Draft California 2026 Integrated Report (303(d) List/305(b) Report)

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for endosulfan (l and ll) in fish tissue is 13,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 164761, Endosulfan	Region 7
Imperial Valley Drains

LOE ID:

126208

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 7 samples exceeded the water quality standard for Endosulfan. Data were collected for 6 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in human, plant, animal, or indigenous aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Endosulfan, Total concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723RICEDR, 723PEACHD, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164761, Endosulfan	Region 7
Imperial Valley Drains

LOE ID:

126398

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 10 samples exceeded the water quality standard for Endosulfan. Data were collected for 6 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 7 station(s) with the station code(s): 723NRFGDN, 723BARWDR, 723NRGNDN, 723RI3DRN, 723SCNTDR, 723CNTDRN, 723OLANDR.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164761, Endosulfan	Region 7
Imperial Valley Drains

LOE ID:

126506

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Data was collected from 7 station(s) with the station code(s): 723NRFGDN, 723BARWDR, 723NRGNDN, 723RI3DRN, 723SCNTDR, 723CNTDRN, 723OLANDR.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164761, Endosulfan	Region 7
Imperial Valley Drains

LOE ID:

46183

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum total Endosulfan concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 164761, Endosulfan	Region 7
Imperial Valley Drains

LOE ID:

126458

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723RICEDR, 723PEACHD, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 164761, Endosulfan	Region 7
Imperial Valley Drains

LOE ID:

5533

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

Toxic Substances Monitoring Program (TSMP) Data for organic and inorganic chemicals in fish and sediment samples collected from water bodies located in the Colorado River Basin-Region 7. 1978-2000. State Water Resources Control Board. Sacramento, CA.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 20,000 ug/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Rice drain 3, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach Drain, Tokay drain, Barbara Worth drain, and Warren drain.

Temporal Representation:

Fish tissue samples were generally collected from 10/1985 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-one fish fillet samples of carp, channel catfish, tilapia, flathead catfish, spiny soft shelled turtle, redbelly tilapia, and yellow bullhead were collected. Eight carp fillet composite samples were collected in the years (2)1985, 1986, 1988, (3)1990, and 1999. Two carp single fish fillet samples were collected in the years 1989-90. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. Two tilapia fillet composite samples were collected in the years 1996, and 2000. One flathead catfish fillet composite sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. One yellow bullhead fillet composite sample was collected in the year 1985. Nineteen whole fish samples of mosquitofish, and sailfin molly were collected. Twelve mosquitofish whole fish composite samples were collected in 1985, 1989, (2)1990, (3)1991, 1995-96, and (3)2000. Seven sailfin molly whole fish composite samples were collected in (2)1989, 1991, (2)1992, (2)2000.

Environmental Conditions:

QAPP Information:

The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 164761, Endosulfan	Region 7
Imperial Valley Drains

LOE ID:

5607

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

The field procedures are described in TSMP Data Reports and associated Appendices. CDFG's Laboratory applies a Quality Assurance Program Plan procedures for laboratory Quality Assurance and Quality Control, as described in Rasmussen (1993).

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.


DECISION ID	170104	Region 7
Imperial Valley Drains

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Reason for Delisting:	Flaws in original listing
TMDL Name:	Imperial Valley Organochlorine Compounds and Organophosphate Pesticides TMDL
TMDL Project Code:	1289
Date TMDL Approved by USEPA:	03/19/2024
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. The number of measured exceedances is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicant pollutants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that this water segment-pollutant combination should not be placed on the CWA section 303(d) List. Refer to the lines of evidence in this fact sheet for the data and information, sample counts and exceedances, quality assurance documentation, beneficial uses, and water quality objectives or numeric evaluation guidelines relied upon for this decision.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 170104, DDE (Dichlorodiphenyldichloroethylene)	Region 7
Imperial Valley Drains

LOE ID:

220743

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Not Recorded

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Sportfish Rivers and Streams data for Kern River, North Fork to determine beneficial use support and the results are as follows 0 of the 1 samples exceeded the water quality standard for Endosulfan. Data were collected for 1 fish species (1 composite(s) of Rainbow Trout each composed of 5 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

This is a placeholder LOE use to generate a decision on the 2020 cyce. It should not be considered for assessment and should be deleted once it has been used for its purpose.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Placeholder

Temporal Representation:

Placeholder

Environmental Conditions:

QAPP Information:

Placeholder

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 170104, DDE (Dichlorodiphenyldichloroethylene)	Region 7
Imperial Valley Drains

LOE ID:

333604

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) .

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Sum DDE from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDE is 31.3 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-08 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170104, DDE (Dichlorodiphenyldichloroethylene)	Region 7
Imperial Valley Drains

LOE ID:

353919

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

0 of the 1 samples collected by SWAMP RWB7 Monitoring for Imperial Valley Drains exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or indigenous aquatic life. (Colorado River Basin Plan)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The sample is toxic when the response of the organisms exposed to the sample is significantly different (worse) than the response of the organisms exposed to the laboratory control based on statistical hypothesis testing. An exceedance is counted when the significant effect code is \Significant; Less Similarity,\ which means that the sample result is significantly different than the control result, and the percent effect is greater than the evaluation threshold. The default evaluation threshold is 20% unless otherwise stated.

Guideline Reference:

Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013

Spatial Representation:

The samples were collected at monitoring site: 723STRDRN ( R Drain Tributary at Alcott and wister road ).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-04-10.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170104, DDE (Dichlorodiphenyldichloroethylene)	Region 7
Imperial Valley Drains

LOE ID:

353879

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

1 of the 2 samples collected by SWAMP RWB7 Monitoring for Imperial Valley Drains exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Growth (wt/surv indiv), Hyalella azteca for Survival. The following tests exhibited toxicity: Hyalella azteca for Growth (wt/surv indiv) on 2019-10-15.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723SSDS03 ( Salton Sea Drain S3 (Trifolium TD1) ).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170104, DDE (Dichlorodiphenyldichloroethylene)	Region 7
Imperial Valley Drains

LOE ID:

353719

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Sum DDE from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDE is 31.3 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170104, DDE (Dichlorodiphenyldichloroethylene)	Region 7
Imperial Valley Drains

LOE ID:

353718

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Sum DDE from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDE is 31.3 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-14 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170104, DDE (Dichlorodiphenyldichloroethylene)	Region 7
Imperial Valley Drains

LOE ID:

353716

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Sum DDE from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDE is 31.3 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	169424	Region 7
Imperial Valley Drains

Pollutant:	Ammonia
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Eighteen lines of evidence are available in the administrative record to assess pollutant. Four of the 29 total fraction water samples and 8 out of 31 toxicity samples exceed the threshold. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Four of the 29 total fraction water samples and eight of 31 toxicity samples exceed the threshold and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354037

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for AmmoniaNAFreshwater 2013 document.

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS02 (Salton Sea Drain S2 (Niland 4)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354045

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354041

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354046

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PEACHD (Peach Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354047

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354042

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354043

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2020-01-14 and 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354038

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354044

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Ammonia as N.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354052

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354049

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

125408

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

7 of the 27 samples collected by SWAMP RWB7 Monitoring for Imperial Valley Drains exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca, for Survival, Hyalella azteca, for Growth (wt/surv indiv)

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Colorado River Basin Plan)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 27 stations. Monitoring site(s): ( 723BDRAIN, 723CENTD2, 723CENTD3, 723CTD3MA, 723EDRAIN, 723ELML6D, 723KDRAIN, 723MARIGD, 723MCALD1, 723OASISD, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PMLEOD, 723QLATDR, 723SCENTD, 723SPRUCD, 723THIS5D, 723TRI12D, 723UADCMC, 723UADGUN, 723UADSPC, 723VAIL7D, 723VAL2AD, 723VERDED, 723WILDCD )

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-11-04.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

125395

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

1 of the 4 samples collected by DPR Surface Water Study 290 Name for Imperial Valley Drains exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Chironomus dilutus, for Ash Free Dry Mass, Chironomus dilutus, for Survival

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DPR Surface Water Study 290 Name.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 4 stations. Monitoring site(s): ( 723IPHV10, 723IPMV61, 723IPRC99, 723IPVD69 )

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15.

Environmental Conditions:

QAPP Information:

A QAPP was not required for this data

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

127558

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 4 of 29 samples exceeded the water quality standard for Ammonia as N.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 28 monitoring site(s) (723BDRAIN, 723CENTD2, 723CENTD3, 723CTD3MA, 723EDRAIN, 723ELML6D, 723KDRAIN, 723MARIGD, 723MCALD1, 723OASISD, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PMLEOD, 723QLATDR, 723SCENTD, 723SPRUCD, 723THIS5D, 723TRI12D, 723UADCMC, 723UADGUN, 723UADSPC, 723VAIL7D, 723VAL2AD, 723VERDED, 723WILDCD, 728SSDS01)

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

220742

Pollutant:

Ammonia

LOE Subgroup:

Pollutant-Tissue

Matrix:

Not Recorded

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP Sportfish Contamination in Lakes and Resrv data for Isabella Lake to determine beneficial use support and the results are as follows 0 of the 1 samples exceeded the water quality standard for Endosulfan. Data were collected for 1 fish species (1 composite(s) of Channel Catfish each composed of 4 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

This is a placeholder LOE use to generate a decision on the 2020 cyce. It should not be considered for assessment and should be deleted once it has been used for its purpose.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Placeholder

Temporal Representation:

Placeholder

Environmental Conditions:

QAPP Information:

Placeholder

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

334567

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2020-01-08 and 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354035

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169424, Ammonia	Region 7
Imperial Valley Drains

LOE ID:

354050

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.


DECISION ID	156116	Region 7
Imperial Valley Drains

Pollutant:	Disulfoton
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Nine lines of evidence are available in the administrative record to assess pollutant. 2 of the 2 total water samples exceed the guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 2 of 2 total fraction water samples exceeded the evaluation guideline and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156116, Disulfoton	Region 7
Imperial Valley Drains

LOE ID:

128890

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the water quality standard for Disulfoton. Although a total of 7 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Data was collected from 23 station(s): (Station Codes 723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723CNTDRN, 723HLVLDR, 723MAGDRN, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OLANDR, 723PEACHD, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCNTDR, 723SPRDRN, 723SSDS02, 723SSDS03, 723SSPDRN, 723TI2DRN, 723VERDRN).

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-08 to 2012-05-09

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156116, Disulfoton	Region 7
Imperial Valley Drains

LOE ID:

125408

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-11-04.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156116, Disulfoton	Region 7
Imperial Valley Drains

LOE ID:

125395

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DPR Surface Water Study 290 Name.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 4 stations. Monitoring site(s): ( 723IPHV10, 723IPMV61, 723IPRC99, 723IPVD69 )

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15.

Environmental Conditions:

QAPP Information:

A QAPP was not required for this data

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 156116, Disulfoton	Region 7
Imperial Valley Drains

LOE ID:

320880

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

Surface Water Ambient Monitoring Program (SWAMP) Data for organic and inorganic constituents in water and sediment samples collected from water bodies located in the Colorado River Basin- Region 7. May 2002 - May 2004.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlordane, Bolstar, Ciodrin, Dacthal, Demeton s, Dichlorvos, Dimethoate, Disulfoton, Endrin Ketone, Ethoprop, Famphur, Mirex, Naled, or Oxodiazon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156116, Disulfoton	Region 7
Imperial Valley Drains

LOE ID:

354486

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Disulfoton. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156116, Disulfoton	Region 7
Imperial Valley Drains

LOE ID:

354494

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156116, Disulfoton	Region 7
Imperial Valley Drains

LOE ID:

354490

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156116, Disulfoton	Region 7
Imperial Valley Drains

LOE ID:

354493

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156116, Disulfoton	Region 7
Imperial Valley Drains

LOE ID:

354487

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	159222	Region 7
Imperial Valley Drains

Pollutant:	Imidacloprid
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. 49 lines of evidence are available in the administrative record to assess pollutant. 33 of the 36 water samples exceed the evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 17 of 17 dissolved water samples exceeded the criteria and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. 8 of 11 total water samples exceeded the criteria and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 5. 8 of 8 water samples with no fraction reported exceeded the criteria and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

125395

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DPR Surface Water Study 290 Name.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 4 stations. Monitoring site(s): ( 723IPHV10, 723IPMV61, 723IPRC99, 723IPVD69 )

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15.

Environmental Conditions:

QAPP Information:

A QAPP was not required for this data

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

351813

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

335417

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Imidacloprid.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354719

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the water quality threshold for Imidacloprid. Although a total of 3 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site (723IPVD69).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354710

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354715

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Imidacloprid. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354721

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354725

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354712

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355861

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354713

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354732

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354729

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355863

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355858

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354736

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354739

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Imidacloprid. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354728

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355870

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354723

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Imidacloprid. Although a total of 3 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site (723IPMV61).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355860

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355859

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355884

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355872

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355867

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354716

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Imidacloprid. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354738

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Imidacloprid. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355874

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355876

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355879

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354718

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site (723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354726

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354711

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355877

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355880

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355857

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723MALVAD (Malva Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355869

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354720

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 3 of 3 samples exceeded the water quality threshold for Imidacloprid.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355873

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355868

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

354733

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355875

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355878

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355862

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355864

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355865

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355866

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

355883

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the 4-day average concentration of Imidacloprid does not exceed 0.016 ug/L.

Guideline Reference:

Water Quality Criteria Report for Imidacloprid Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology. University of California, Davis

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159222, Imidacloprid	Region 7
Imperial Valley Drains

LOE ID:

125408

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-11-04.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	156142	Region 7
Imperial Valley Drains

Pollutant:	PCBs (Polychlorinated biphenyls)
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	Agriculture
TMDL Name:	Imperial Valley Organochlorine Compounds and Organophosphate Pesticides TMDL
TMDL Project Code:	1289
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the section 303(d) list under sections 2.2, 3.11, 4.1, 4.5 and 4.6 of the Listing Policy. Under these sections of the Policy, a minimum of one line of evidence is needed to assess listing status. At least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. Under section 3.11 when all other listing factors do not result in the listing of a water segment but information indicates non-attainment of standards, a water segment shall be evaluated to determine whether the weight of evidence demonstrates that water quality standard is not attained. If the weight of evidence indicates non-attainment, the water segment shall be placed on the CWA section 303(d) List. They may be approved by RBs in resolutions The COMM beneficial use has not been designated to this waterbody. While there is not a specific health advisory for Imperial Valley Drains, in 2022 OEHHA released Statewide Health Advisory and Guidelines for Eating Fish from California’s Rivers, Streams, and Creeks without Site-Specific Advice for PCBs. Fishing occurs at Imperial Valley Drains and the fish species common carp used for the assessments in LOE 126632 and 126267 are part of 2022 Advisory.¿ Also, data were collected in this waterbody by the Surface Water Ambient Monitoring Program to monitor pollutants in fish tissue for the purpose of evaluating risks to human health from consumption. Twelve lines of evidence are available in the administrative record to assess this pollutant. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. LOE 5108 was removed from the decision because it was split apart into multiple individual pollutant LOEs. LOE 321033 replaces the corresponding data. Eight of 8 total fraction fish tissue samples exceeded the OEHHA fish contaminant goal. Nine of 12 fish fillet fraction fish tissue samples exceeded the modified OEHHA fish tissue evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eight of 8 total fraction fish tissue samples exceeded the OEHHA fish contaminant goal. Nine of 12 fish fillet fraction fish tissue samples exceeded the modified OEHHA fish tissue evaluation guideline. These exceed the allowable frequency listed in Table 4.1 of the Listing Policy. This pollutant is a possible cause or contributor to toxicity. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

125408

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-11-04.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

125395

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DPR Surface Water Study 290 Name.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 4 stations. Monitoring site(s): ( 723IPHV10, 723IPMV61, 723IPRC99, 723IPVD69 )

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15.

Environmental Conditions:

QAPP Information:

A QAPP was not required for this data

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

321033

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Consensus Based Sediment Quality Guideline Probable Effects Concentrations (PECs) for the protection of freshwater organisms to toxic effects were used for the following constituents: 33 mg/kg Arsenic, 1050 ug/kg Benz[a]anthrazene, 4.98 mg/kg Cadmium, 111 mg/kg Chromium, 1290 ug/kg Chrysene, 149 mg/kg Copper, 61.8 ug/g Dieldrin, 207 ug/kg Endrin, 2230 ug/kg Fluoranthene, 536 ug/kg Fluorene, 128 mg/kg Lead, 4.99 ug/kg Lindane/Hexachlorocyclohexane (HCH), 1.06 mg/kg Mercury, 561 ug/kg Naphthalene, 48.6 mg/kg Nickel, 676 ug/kg PCBs (Polychlorinated biphenyls), 1170 ug/kg Phenanthrene , 1520 ug/kg Pyrene (Macdonald et al, 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

353825

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan, Colorado River Basin)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for total PCBs is the probable effect concentration (PEC) of 676 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

355071

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for PCBs (Polychlorinated biphenyls). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The PCB, total aroclors criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.014 ug/L. This value corresponds to the sum of aroclors 1242, 1254, 1221, 1232, 1248, 1260, and 1016 (California Toxics Rule, 2000).

Objective/Criterion Reference:

Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

46230

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 3 of 4 samples exceed the criterion for PCB, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites were averaged for species collected at the same time and location. Composites comprised of 2-3 fish for channel catfish and 1 fish for Tilapia spp. and flathead catfish. Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for polychlorinated biphenyls in fish tissue is 2.6 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

5647

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in imperial valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, none exceeded the NAS tissue guideline. (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 500 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

126632

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 2 of the 3 samples exceeded the water quality standard for PCBs (Polychlorinated biphenyls). Data were collected for 3 fish species (1 composite(s) of Mosquitofish each composed of 60 fish per composite, 1 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite). Of these, 1 species (Mosquitofish) exceeded the water quality standard.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data was collected from 3 station(s) with the station code(s): 723SCNTDR, 723CNTDRN, 723NRFGDN.

Temporal Representation:

Data for this line of evidence were collected between 2012-10-15 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

126518

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 5 samples exceeded the water quality standard for PCBs (Polychlorinated biphenyls). Data were collected for 5 fish species (1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum total PCB concentration of 500 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 3 station(s) with the station code(s): 723RICEDR, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-11 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

126633

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 3 samples exceeded the water quality standard for PCBs (Polychlorinated biphenyls). Data were collected for 3 fish species (1 composite(s) of Mosquitofish each composed of 60 fish per composite, 1 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 3 station(s) with the station code(s): 723SCNTDR, 723CNTDRN, 723NRFGDN.

Temporal Representation:

Data for this line of evidence were collected between 2012-10-15 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

46243

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for PCB, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites were averaged for species collected at the same time and location. Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

5441

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. Eighteen fish fillet and 14 whole fish sample results could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The 3 fish fillet samples and 5 whole fish samples that were acceptable were generally collected from 12/1999 through 11/2000. Of these total samples, 3 fish fillet samples and 5 whole fish samples collected at 5 locations exceeded the OEHHA Fish Contaminant Goal. At Holtville Main drain an exceedance was found in 1 channel catfish fillet composite sample collected on 12/05/1999. At Central drain exceedances were found in 1 carp fillet composite sample collected on 12/05/1999, and 1 sailfin molly whole fish composite sample collected on 11/08/2000. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample collected on 12/05/1999, and 1 sailfin molly whole fish composite sample collected on 11/08/2000. At Greeson an exceedance was found in 1 mosquitofish whole fish composite sample collected on 11/07/2000. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples collected on (2)11/08/2000 (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 3.6 ug/kg to protect human health when consuming fish (OEHHA, 2008).

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156142, PCBs (Polychlorinated biphenyls)	Region 7
Imperial Valley Drains

LOE ID:

126267

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 4 of the 5 samples exceeded the water quality standard for PCBs (Polychlorinated biphenyls). Data were collected for 5 fish species (1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite). Of these, 2 species (Mosquitofish, Common Carp) exceeded the water quality standard.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data was collected from 3 station(s) with the station code(s): 723RICEDR, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-11 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	159219	Region 7
Imperial Valley Drains

Pollutant:	Selenium
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under section 4.1, 4.5, and 4.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Beneficial use support for Commercial or recreational collection of fish, shellfish, or organisms will be reassessed in a future cycle, if more data are available. Thirteen lines of evidence are available in the administrative record to assess pollutant. Zero sediment and tissue samples exceeded the objectives. Forty-two of 63 dissolved water samples exceed the continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater (California Toxics Rule, 2000) for the "Warm Freshwater Habitat" beneficial use assessed. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero sediment and tissue samples exceeded the objectives, however, forty-two of 63 dissolved water samples exceed the continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater (California Toxics Rule, 2000) for the "Warm Freshwater Habitat" beneficial use assessed. This exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. This pollutant is a possible cause or contributor to toxicity. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

355271

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQX from the NWQMP for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

355378

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed USGS California Water Science Center data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Selenium.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-331043115365301 (SONNY BONO SALTON SEA NWR E POND NR NILAND CA).

Temporal Representation:

The samples were collected between the dates of 2021-05-14 and 2021-05-14

Environmental Conditions:

QAPP Information:

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

355379

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQX from the NWQMP for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: USGS-331052115365301 (SONNY BONO SALTON SEA NWR NE POND SITE C NR NILAND).

Temporal Representation:

The samples were collected between the dates of 2021-05-14 and 2021-05-14

Environmental Conditions:

QAPP Information:

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

QAPP Information Reference(s):

QAPP for USGS Data Collected during the 2026 Integrated Report Cycle

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

355273

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

355274

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Selenium.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

129013

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 40 of 56 samples exceeded the water quality standard for Selenium.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 32 monitoring site(s) (723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723CNTDRN, 723CTD3MA, 723HLVLDR, 723MAGDRN, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OASISD, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PEACHD, 723PMLEOD, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCENTD, 723SCNTDR, 723SPRDRN, 723SSDS02, 723SSDS03, 723SSPDRN, 723TI2DRN, 723UADGUN, 723VERDED, 723VERDRN)

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

336173

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

30274

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).

No evaluation guideline for the sediment fraction of Selenium for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Sediment samples were collected and analyzed in May of 2002 at all three sampling locations. In October of 2002 sediment samples were collected and analyzed at the Niland 4 and Trifolium TD1 sampling locations only.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

5443

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-three fish fillet samples and 24 whole fish samples were taken at 19 locations in Imperial Valley drains. The samples were generally collected from 10/1986 through 11/2000. Of these total samples, none exceeded the OEHHA Fish Contaminant Goal (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 7400 ppb to protect human health when consuming fish (OEHHA, 2008).

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Samples were collected from the following Imperial Valley drain locations; Rose drain, Holtville Main drain, Central drain, South Central drain, Verde drain, Greeson drain, Fig drain, Pumice drain, Mayflower drain, Orange drain, Peach drain, Tokay drain, Barbara Worth drain, Warren drain, Dixie drain No.1, Dixie drain No.3, Dixie drain No.5, Forgetmenot drain, and West Side drain.

Temporal Representation:

Fish tissue samples were generally collected from 10/1986 through 11/2000. Fish tissue samples were not collected from each location every sampling round. Twenty-three fish fillet samples of carp, tilapia, channel catfish, flathead catfish, spiny soft shell turtle, redbelly tilapia, and Mozambique tilapia were collected. Seven carp fillet composite samples were collected in the years 1985, (2)1986, (3)1990 and 1999. Three carp single fish fillet samples were collected in the years 1986, 1989-90. Two tilapia fillet composite samples were collected in the years 1996, and 2000. Three channel catfish fillet composite samples were collected in the years 1989-90, and 1999. One channel catfish single fish fillet sample was collected in the year 1999. One flathead catfish single fish fillet sample was collected in the year 1988. Two spiny soft shelled turtle fillet composite samples were collected in the year (2)1992. One redbelly tilapia fillet composite sample was collected in the year 1992. Three Mozambique tilapia fillet composite samples were collected in year (3)1986. Twenty-four whole fish composite samples of mosquitofish, and sailfin molly were collected. Fifteen mosquitofish whole fish composite samples were collected in the years 1985, (2)1986, 1989, (2)1990, (4)1991, 1995-96, (3)2000. Nine sailfin molly whole fish composite samples were collected in the years (3)1986, (2)1989, 1991, (2)1992, 2000.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

125408

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-11-04.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

125395

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DPR Surface Water Study 290 Name.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 4 stations. Monitoring site(s): ( 723IPHV10, 723IPMV61, 723IPRC99, 723IPVD69 )

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15.

Environmental Conditions:

QAPP Information:

A QAPP was not required for this data

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

46244

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Selenium. Seventeen composites (1 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The OEHHA Fish Contaminant Goal for selenium in fish tissue is 7.4 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A background dietary consumption rate of 0.114 mg/day is applied for this micronutrient.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 159219, Selenium	Region 7
Imperial Valley Drains

LOE ID:

126269

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 8 samples exceeded the water quality standard for Selenium. Data were collected for 8 fish species (1 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Mosquitofish each composed of 7 fish per composite, 1 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 105 fish per composite, 1 composite(s) of Mosquitofish each composed of 37 fish per composite, 3 composite(s) of Common Carp each composed of 1 fish per composite, 5 composite(s) of Tilapia spp. each composed of 1 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data was collected from 7 station(s) with the station code(s): 723BARWDR, 723SCNTDR, 723NRGNDN, 723OLANDR, 723NRFGDN, 723CNTDRN, 723PEACHD.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-08 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	156150	Region 7
Imperial Valley Drains

Pollutant:	Toxaphene
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Name:	Imperial Valley Organochlorine Compounds and Organophosphate Pesticides TMDL
TMDL Project Code:	1289
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the section 303(d) list under sections 2.2 and 4.5 of the Listing Policy. Under these sections of the Policy, a minimum of one line of evidence is needed to assess listing status. The COMM beneficial use has not been designated to this waterbody. However, data were collected in this waterbody by the Surface Water Ambient Monitoring Program to monitor pollutants in fish tissue for the purpose of evaluating risks to human health from consumption. Data were collected as recent as 2012 and 23 out of 23 samples exceed the allowable frequency based on table 3.1 of the Listing Policy. The weight of evidence of the data and information indicate water quality standards are not attained. Seven lines of evidence are available in the administrative record to assess this pollutant. Twenty-three of 23 total fraction fish tissue samples exceeded the OEHHA fish contaminant goal. Twenty-one of 40 total fraction fish tissue samples exceeded the NAS fish tissue evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twenty-three of 23 total fraction fish tissue samples exceeded the OEHHA fish contaminant goal. Twenty-one of 40 total fraction fish tissue samples exceeded the NAS fish tissue evaluation guideline. These exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

Line of Evidence (LOE) for Decision ID 156150, Toxaphene	Region 7
Imperial Valley Drains

LOE ID:

46245

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Eleven samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for toxaphene in fish tissue is 4.3 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156150, Toxaphene	Region 7
Imperial Valley Drains

LOE ID:

46246

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Toxaphene. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Toxaphene concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156150, Toxaphene	Region 7
Imperial Valley Drains

LOE ID:

355333

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Toxaphene. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The toxaphene criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0002 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156150, Toxaphene	Region 7
Imperial Valley Drains

LOE ID:

319648

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Aldrin, Chlorpyrifos, Diazinon, or Toxaphene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156150, Toxaphene	Region 7
Imperial Valley Drains

LOE ID:

127204

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Toxaphene. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Toxaphene criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0002 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 23 station(s) (Station Code(s) 723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723CNTDRN, 723HLVLDR, 723MAGDRN, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OLANDR, 723PEACHD, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCNTDR, 723SPRDRN, 723SSDS02, 723SSDS03, 723SSPDRN, 723TI2DRN, 723VERDRN).

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-07 to 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156150, Toxaphene	Region 7
Imperial Valley Drains

LOE ID:

5658

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156150, Toxaphene	Region 7
Imperial Valley Drains

LOE ID:

2958

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Five out of 5 samples exceeded the NAS guideline. A total of 5 whole fish composite samples of mosquitofish and sailfin molly were collected. Two mosquitofish samples were collected in 2000 and 3 sailfin molly samples were collected in 1992 and 2001-02. The guideline was exceeded in all samples (TSMP, 2002).

Two out of 2 samples exceeded the OEHHA guideline. One filet composite sample (1999) and 1 individual filet sample (2002) of carp were collected. Both samples were in exceedance.

Three out of 3 samples exceeded the NAS guideline. A total of 3 whole fish composite samples of sailfin molly and mosquitofish were collected. One sailfin molly sample was collected in 1992 and 2 mosquitofish samples were collected in 1995-96. The guideline was exceeded in all samples.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Colorado River Basin RWQCB Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

NAS Guideline (whole fish) 100 ng/g and OEHHA Screening Value 30 ng/g.

Guideline Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Spatial Representation:

The Barbara Worth Drain, Peach Drain, and Rice Drain only. For the 5 samples: 1 station located off Anderhold Road south of Highway S80 where drain comes alongside road. This information only applies to the Barbara Worth Drain area of the Imperial Valley Drains. For the 2 samples: 1 station located downstream of Meloland Road. This information only applies to the Central Drain area of the Imperial Valley Drains. For the 3 samples: One station located at highway 115 crossing. This information only applies to the Peach Drain area of the Imperial Valley Drains.

Temporal Representation:

Samples were collected on 12-5-1999, 10/22/2002, in 1992, 1995-1996 and 2000-2002.

Environmental Conditions:

QAPP Information:

Toxic Substances Monitoring Program 1992-93 Data Report.

Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 1996-2000. Department of Fish and Game.

Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 2001-2002. Department of Fish and Game.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156150, Toxaphene	Region 7
Imperial Valley Drains

LOE ID:

5442

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. Nine fish fillet and eight whole fish sample results could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentrations. The 12 fish fillet samples and 11 whole fish samples that were acceptable were generally collected from 12/1922 through 11/2000. Of these total samples, 12 fish fillet samples and 11 whole fish samples collected at 12 locations exceeded the OEHHA Fish Contaminant Goal. At Rose drain an exceedance was found in 1 carp fillet composite sample. At Holtville Main drain exceedances were found in 2 channel catfish fillet composite samples. At Central drain exceedances were found in 1 carp fillet composite sample, and 1 sailfin molly whole fish composite sample. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample, 1 carp single fish fillet sample, and 1 sailfin molly whole fish composite sample. At Rice drain 3 exceedances were found in 2 carp fillet composite samples. At Verde drain an exceedance was found in 1 carp single fish fillet sample. At Greeson drain exceedances were found in 1 carp fillet composite sample, 1 yellow bullhead fillet composite sample, and 1 mosquitofish whole fish composite sample. At Pumice drain an exceedance was found in 1 channel catfish fillet composite sample. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Orange drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 6.1 ug/kg to protect human health when consuming fish (OEHHA, 20008).

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.


DECISION ID	159220	Region 7
Imperial Valley Drains

Pollutant:	Toxicity
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown \| Agriculture
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Eight lines of evidence are available in the administrative record to assess pollutant in the water and sediment matrices. Ten of the 39 water samples exceed the evaluation guideline for water aquatic life toxicity. One of the 3 sediment samples exceed the evaluation guideline for sediment aquatic life toxicity. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Ten of the 39 water samples exceed the evaluation guideline for water aquatic life toxicity and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159220, Toxicity	Region 7
Imperial Valley Drains

LOE ID:

353916

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723WRMWDD ( Wormwood Drain ).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DPR Surface Water Study 290 Name.

Line of Evidence (LOE) for Decision ID 159220, Toxicity	Region 7
Imperial Valley Drains

LOE ID:

125395

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 4 stations. Monitoring site(s): ( 723IPHV10, 723IPMV61, 723IPRC99, 723IPVD69 )

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15.

Environmental Conditions:

QAPP Information:

A QAPP was not required for this data

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 159220, Toxicity	Region 7
Imperial Valley Drains

LOE ID:

353879

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723SSDS03 ( Salton Sea Drain S3 (Trifolium TD1) ).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159220, Toxicity	Region 7
Imperial Valley Drains

LOE ID:

353891

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

1 of the 3 samples collected by SWAMP RWB7 Monitoring for Imperial Valley Drains exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival. The following tests exhibited toxicity: Hyalella azteca for Survival on 2019-04-08.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723SSDS03 ( Salton Sea Drain S3 (Trifolium TD1) ).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2020-01-07.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159220, Toxicity	Region 7
Imperial Valley Drains

LOE ID:

353905

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

0 of the 2 samples collected by SWAMP RWB7 Monitoring for Imperial Valley Drains exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723STRDRN ( R Drain Tributary at Alcott and wister road ).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-10-16.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159220, Toxicity	Region 7
Imperial Valley Drains

LOE ID:

353886

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

1 of the 2 samples collected by SWAMP RWB7 Monitoring for Imperial Valley Drains exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day and the same location. The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca for Survival. The following tests exhibited toxicity: Hyalella azteca for Survival on 2020-01-08.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723IPYG46 ( Vail Drain Near Young ).

Temporal Representation:

The samples were collected between the dates of 2019-10-16 and 2020-01-08.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159220, Toxicity	Region 7
Imperial Valley Drains

LOE ID:

353919

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723STRDRN ( R Drain Tributary at Alcott and wister road ).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-04-10.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159220, Toxicity	Region 7
Imperial Valley Drains

LOE ID:

125408

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-11-04.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	156104	Region 7
Imperial Valley Drains

Pollutant:	Chlordane
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	Agriculture
TMDL Name:	Imperial Valley Organochlorine Compounds and Organophosphate Pesticides TMDL
TMDL Project Code:	1289
Date TMDL Approved by USEPA:	03/19/2024
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the section 303(d) list under sections 2.2 and 4.5 of the Listing Policy. Under these sections of the Policy, a single line of evidence is needed to assess listing status. The COMM beneficial use has not been designated to this waterbody. However, data were collected in this waterbody by the Surface Water Ambient Monitoring Program to monitor pollutants in fish tissue for the purpose of evaluating risks to human health from consumption. LOE 5438 was not used for this assessment and the data has been replaced with LOE 46768 due to an updated Fish Contaminant Goal from OEHHA. 11 LOEs are available for to assess this pollutant. 15 of 27 samples exceed the tissue quality threshold for the fish fillet fraction for commercial or recreational collection of fish and 20 of 40 samples exceed the tissue quality threshold for the total fraction for commercial or recreational collection of fish. This does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy. The weight of evidence of the data and information indicate water quality standards are not attained. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Twenty of 40 total fraction and 15 of 27 fish fillet fraction fish tissue samples exceeded the modified OEHHA fish contaminant goal for the "Commercial or recreational collection of fish, shellfish, or organisms" beneficial use assessed. This does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

353642

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chlordane is the probable effect concentration (PEC) of 17.6 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

320035

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: 3 ug/l Aldrin, 0.22 ug/l alpha Endosulfan, 340 ug/l Arsenic, 0.22 ug/l beta-Endosulfan, 2.4 ug/l Chlordane, 0.52 ug/l Heptachlor, and 0.52 ug/l Heptachlor epoxide (USEPA, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

320863

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

5581

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, 1 fish fillet samples collected at 1 location exceeded the NAS tissue guideline. At Rice drain 3 an exceedence was found in 1 carp fillet composite sample collected on 10/10/1985. (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

46768

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish tissue samples were generally collected from 10/1985 through 11/2000. Of these total samples, 9 fish fillet samples and 10 whole fish samples collected at 10 locations exceeded the OEHHA Fish Contaminant Goal. At Holtville Main drain exceedances were found in 2 channel catfish fillet composite samples collected on 10/28/1989, and 12/05/1999. At Central drain exceedances were found in 1 carp fillet composite sample collected on 12/05/1999, and 1 sailfin molly whole fish composite sample collected on 11/08/2000. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample collected on 12/05/1999, and 1 carp single fish fillet collected on 8/01/1990. At Rice drain 3 an exceedance was found in 1 carp fillet composite sample collected on 10/10/1985. At Greeson exceedances were found in 1 carp fillet composite sample collected on 11/15/1985, 1 spiny soft-shelled turtle collected on 9/18/1992, and 1 mosquitofish whole fish composite sample collected on 11/07/2000. At Pumice drain an exceedance was found in 1 channel catfish fillet composite sample collected on 11/20/1990. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample collected on 8/16/1991. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples collected on 10/28/1995, and 11/03/1996, and 1 sailfin molly whole fish composite sample collected on 9/17/1992. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples collected on (2)11/08/2000, and 1 sailfin molly whole fish composite sample collected on 9/17/1992. At Warren Drain an exceedance was found in 1 mosquitofish whole fish composite sample collected on 9/09/1990 (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for total chlordane in fish tissue is 3.9 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

126607

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 7 of the 8 samples exceeded the water quality standard for Total Chlordanes. Data were collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite). Of these, 2 species (Mosquitofish, Common Carp) exceeded the water quality standard.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723PEACHD, 723RICEDR, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

46001

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Chlordane, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Total chlordane was calculated as the sum of the following chlordane isomers: cis- and trans-chlordane, cis- and trans-nonachlor, and oxychlordane. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum total Chlordane concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

126387

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 8 samples exceeded the water quality standard for Total Chlordanes. Data were collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723PEACHD, 723RICEDR, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

126565

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 15 samples exceeded the water quality standard for Total Chlordanes. Data were collected for 11 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 1 composite(s) of Mosquitofish each composed of 15 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 60 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Mosquitofish each composed of 7 fish per composite, 1 composite(s) of Mosquitofish each composed of 37 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 8 station(s) with the station code(s): 723OLANDR, 723NRGNDN, 723PEACHD, 723CNTDRN, 723NRFGDN, 723RI3DRN, 723SCNTDR, 723BARWDR.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

46000

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 3 of 4 samples exceed the criterion for Chlordane, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Total chlordane was calculated as the sum of the following chlordane isomers: cis- and trans-chlordane, cis- and trans-nonachlor, and oxychlordane. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

126564

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 5 of the 15 samples exceeded the water quality standard for Total Chlordanes. Data were collected for 11 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 1 composite(s) of Mosquitofish each composed of 15 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 60 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Mosquitofish each composed of 7 fish per composite, 1 composite(s) of Mosquitofish each composed of 37 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite). Of these, 1 species (Mosquitofish) exceeded the water quality standard.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data was collected from 8 station(s) with the station code(s): 723OLANDR, 723NRGNDN, 723PEACHD, 723CNTDRN, 723NRFGDN, 723RI3DRN, 723SCNTDR, 723BARWDR.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156104, Chlordane	Region 7
Imperial Valley Drains

LOE ID:

5438

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 5.6 ug/kg to protect human health when consuming fish (OEHHA, 2008).

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.


DECISION ID	156105	Region 7
Imperial Valley Drains

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	Agriculture
TMDL Name:	Imperial Valley Organochlorine Compounds and Organophosphate Pesticides TMDL
TMDL Project Code:	1289
Date TMDL Approved by USEPA:	03/19/2024
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the CWA section 303(d) List under sections 2.2 and 4.1 of the Listing Policy. Under 4.1 of the Policy, a minimum of one line of evidence is needed to assess listing status. 20 lines of evidence are available in the administrative record to assess this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 24 of 33 samples exceeded the water quality threshold for warm freshwater habitat for the not recorded fraction, 16 of 18 samples exceeded the water quality threshold for warm freshwater habitat for the total fraction, and 8 of 31 samples exceeded the toxicity threshold for warm freshwater habitat and these exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. The Imperial Valley Organochlorine Compounds and Organophosphate Pesticides TMDL was approved by USEPA on 3/19/2024. 5. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354225

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005)

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

334761

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354220

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 8 of 8 samples exceeded the water quality threshold for Chlorpyrifos.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354208

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 6 of 7 samples exceeded the water quality threshold for Chlorpyrifos.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354210

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354209

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354213

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354211

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354216

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorpyrifos.

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354212

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorpyrifos.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354221

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 2 of 8 samples exceeded the water quality threshold for Chlorpyrifos.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354222

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354205

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354230

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

354203

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

319634

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Aldrin, Chlorpyrifos, Diazinon, or Toxaphene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

125395

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DPR Surface Water Study 290 Name.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 4 stations. Monitoring site(s): ( 723IPHV10, 723IPMV61, 723IPRC99, 723IPVD69 )

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15.

Environmental Conditions:

QAPP Information:

A QAPP was not required for this data

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

125408

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-11-04.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

127974

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 12 of the 12 samples exceeded the water quality standard for Chlorpyrifos. Although a total of 23 samples were collected, 11 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 ug/L (Siepmann and Finlayson 2000).

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Data was collected from 49 station(s): (Station Codes 723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723BDRAIN, 723CENTD2, 723CENTD3, 723CNTDRN, 723CTD3MA, 723EDRAIN, 723ELML6D, 723HLVLDR, 723KDRAIN, 723MAGDRN, 723MARIGD, 723MCALD1, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OASISD, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PEACHD, 723PMLEOD, 723QLATDR, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCENTD, 723SCNTDR, 723SPRDRN, 723SPRUCD, 723SSDS02, 723SSDS03, 723SSPDRN, 723THIS5D, 723TI2DRN, 723TRI12D, 723UADCMC, 723UADGUN, 723UADSPC, 723VAIL7D, 723VAL2AD, 723VERDED, 723VERDRN, 723WILDCD).

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-07 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

46002

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Chlorpyrifos. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for chlorpyrifos in fish tissue is 660 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156105, Chlorpyrifos	Region 7
Imperial Valley Drains

LOE ID:

5531

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 10000 ug/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.


DECISION ID	169663	Region 7
Imperial Valley Drains

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	Agriculture
TMDL Name:	Imperial Valley Organochlorine Compounds and Organophosphate Pesticides TMDL
TMDL Project Code:	1289
Date TMDL Approved by USEPA:	03/19/2024
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the section 303(d) list under sections 2.2 and 4.5 of the Listing Policy. Under these sections of the Policy, a minimum of one line of evidence is needed to assess listing status. The COMM beneficial use has not been designated to this waterbody. However, data were collected in this waterbody by the Surface Water Ambient Monitoring Program to monitor pollutants in fish tissue for the purpose of evaluating risks to human health from consumption. Data were collected as recent as 2018 and 39 of 40 and 20 of 28 samples exceed the allowable frequency based on table 4.1 of the Listing Policy. The weight of evidence of the data and information indicate water quality standards are not attained. Nineteen lines of evidence are available in the administrative record to assess this pollutant. Thirty-nine of 40 tissue samples exceeded the Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal for consuming fish for the total fraction for the "Commercial or recreational collection of fish, shellfish, or organisms" (COMM) beneficial use assessed. Twenty of 28 tissue samples exceeded the modified OEHHA Fish Contaminant Goal for consuming fish for the fish fillet fraction for the COMM beneficial use assessed. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. There were no exceedances for water samples; however, tissue samples exceedances (see a, b and d below) and sediment sample exceedances (see g below), did not allow for delisting. Exceedances are as follows: a) Thirty-nine of 40 tissue samples exceeded the OEHHA Fish Contaminant Goal for consuming fish for the total fraction for the COMM beneficial use assessed. b) Twenty of 28 tissue samples exceeded the modified OEHHA Fish Contaminant Goal for consuming fish for the fish fillet fraction for the COMM beneficial use assessed. c) Fourteen of 40 tissue samples exceeded the National Academy of Science (NAS) tissue guideline for the protection of aquatic life uses (NAS, 1973). for the total fraction for the "Warm Freshwater Habitat" beneficial use assessed. d) Two of 28 tissue samples exceeded the National Academy of Science guidelines (NAS 1972) maximum concentration (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances. for the fish fillet fraction for the "Warm Freshwater Habitat" beneficial use assessed. e) Zero of six water samples exceeded the California Toxics Rule (CTR) Criterion Maximum Concentration (CMC) for the protection of freshwater aquatic life uses (USEPA, 2000) for the dissolved fraction for the "Warm Freshwater Habitat" beneficial use assessed. f) Zero of 43 water samples exceeded the criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater (California Toxics Rule, 2000) for the total fraction for the "Warm Freshwater Habitat" beneficial use assessed. g.) Three of 6 sediment samples exceeded the probable effect concentration (PEC) of 572 ug/kg dry weight to protect aquatic life for the "Warm Freshwater Habitat" beneficial use and sediment toxicity is not exhibited. Tissue samples exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

354360

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The DDT(4,4') criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

126593

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 8 of the 16 samples exceeded the water quality standard for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD). Data were collected for 12 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 1 composite(s) of Mosquitofish each composed of 15 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 60 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Mosquitofish each composed of 7 fish per composite, 1 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 37 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite). Of these, 2 species (Mosquitofish, Common Carp) exceeded the water quality standard.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for total DDT in fish tissue is 15 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data was collected from 8 station(s) with the station code(s): 723CNTDRN, 723OLANDR, 723BARWDR, 723RI3DRN, 723NRGNDN, 723SCNTDR, 723PEACHD, 723NRFGDN.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

353854

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

353853

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

353857

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-14 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

353919

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723STRDRN ( R Drain Tributary at Alcott and wister road ).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-04-10.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

353879

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723SSDS03 ( Salton Sea Drain S3 (Trifolium TD1) ).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

5058

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) Criterion Maximum Concentration (CMC) of 1.1 ug/l for the protection of freshwater aquatic life uses (USEPA, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

5439

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. The fish samples were generally collected from 10/1985 through 11/2000. Of these total samples, 20 fish fillet samples and 19 whole fish samples collected at 15 locations exceeded the OEHHA Fish Contaminant Goal. At Rose drain exceedances were found in 1 carp fillet composite sample, and 1 mosquitofish whole fish composite sample. At Holtville Main drain exceedances were found in 2 channel catfish fillet composite samples, 1 tilapia fillet compostie sample, and 1 carp fillet composite sample. At Central drain exceedances were found in 1 carp fillet composite sample, 1 flathead catfish single fish fillet sample, and 1 sailfin molly whole fish composite sample. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample, 1 carp single fish fillet sample, 1 spiny soft shelled turtle fillet composite sample, and 1 sailfin molly whole fish composite sample. At Rice drain 3 exceedances were found in 2 carp fillet composite samples. At Verde drain an exceedance was found in 1 carp single fish fillet sample. At Greeson exceedances were found in 1 carp fillet composite sample, 1 yellow bullhead fillet composite sample, 1 spiny soft shelled turtle fillet composite sample, and 1 mosquitofish whole fish composite sample. At Fig drain exceedances were found in 1 carp fillet composite sample, 1 mosquitofish whole fish composite sample, and 3 sailfin molly whole fish composite samples. At Pumice drain exceedances were found in 1 channel catfish fillet composite sample, 1 tilapia fish composite sample, and 1 carp fillet composite sample. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Orange drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Tokay drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Warren drain exceedances were found in 2 mosquitofish whole fish composite samples (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 21 ug/kg to protect human health when consuming fish (OEHHA, 2008).

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

5591

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 1000 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

127400

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for DDT (Dichlorodiphenyltrichloroethane).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The DDT(4,4') criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

127818

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 42 samples exceeded the water quality standard for DDT (Dichlorodiphenyltrichloroethane).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The DDT(4,4') criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 23 monitoring site(s) (723ARCDRN, 723CNTDRN, 723NRGNDN, 723SSPDRN, 723RICEDR, 723SSDS02, 723RI3DRN, 723MUNDRN, 723SSDS03, 723SCNTDR, 723ARNDRN, 723HLVLDR, 723TI2DRN, 723OLANDR, 723VERDRN, 723MAGDRN, 723ROSDRN, 723BARWDR, 723SPRDRN, 723PEACHD, 723NRFGDN, 723ARIDRN, 723NETDRN)

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

333736

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for total DDTs is the probable effect concentration (PEC) of 572 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-08 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

46166

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for DDT, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Total DDT was calculated as the sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum total DDT concentration of 1000 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

126594

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 2 of the 16 samples exceeded the water quality standard for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD). Data were collected for 12 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 1 composite(s) of Mosquitofish each composed of 15 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 60 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Mosquitofish each composed of 7 fish per composite, 1 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 37 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite). Of these, 1 species (Mosquitofish) exceeded the water quality standard.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 8 station(s) with the station code(s): 723CNTDRN, 723OLANDR, 723BARWDR, 723RI3DRN, 723NRGNDN, 723SCNTDR, 723PEACHD, 723NRFGDN.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

126361

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 8 samples exceeded the water quality standard for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD). Data were collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723PEACHD, 723RICEDR, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

46165

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 4 of 4 samples exceed the criterion for DDT, Total. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Total DDT was calculated as the sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

126155

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 8 of the 8 samples exceeded the water quality standard for Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD). Data were collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite). Of these, 2 species (Mosquitofish, Common Carp) exceeded the water quality standard.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723PEACHD, 723RICEDR, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169663, DDT (Dichlorodiphenyltrichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

353724

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for the sum of DDT is the probable effect concentration (PEC) of 62.9 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156115	Region 7
Imperial Valley Drains

Pollutant:	Dieldrin
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	Agriculture
TMDL Name:	Imperial Valley Organochlorine Compounds and Organophosphate Pesticides TMDL
TMDL Project Code:	1289
Date TMDL Approved by USEPA:	03/19/2024
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the CWA section 303(d) List under sections 2.2 and 4.1 of the Listing Policy. Under 4.1 of the Policy, a minimum of one line of evidence is needed to assess listing status. 16 lines of evidence are available in the administrative record to assess this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eight of eight samples exceed the tissue quality threshold for the fish fillet fraction for commercial or recreational collection of fish, 36 of 36 samples exceed the tissue quality threshold for the total fraction for the commercial or recreational collection of fish, four of 40 samples exceed the tissue quality threshold for warm freshwater habitat, and eight of 31 samples exceed the water quality threshold for warm freshwater habitat. These exceed the allowable frequency listed in Table NUMBER of the Listing Policy. 4. The TMDL NAME was approved by USEPA on MM/DD/YEAR. 5. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

320997

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

319308

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: 1724 ug/l Chromium, 0.24 ug/l Dieldrin, and 0.086 ug/l Endrin (USEPA, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

353735

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dieldrin is the probable effect concentration (PEC) of 61.8 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

354438

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

126645

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 2 of the 2 samples exceeded the water quality standard for Dieldrin. Data were collected for 3 fish species (1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Common Carp each composed of 5 fish per composite, 2 composite(s) of Tilapia spp. each composed of 5 fish per composite). Of these species, 2 species (Tilapia spp., Common Carp) exceeded the evaluation guideline. Although a total of 4 samples were collected 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for dieldrin in fish tissue is 0.32 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data was collected from 3 station(s) with the station code(s): 723NRFGDN, 723RI3DRN, 723NRGNDN.

Temporal Representation:

Data for this line of evidence were collected between 2012-10-15 and 2012-10-16

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

126583

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 2 of the 2 samples exceeded the water quality standard for Dieldrin. Data were collected for 3 fish species (1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite). Of these species, 2 species (Common Carp, Mosquitofish) exceeded the evaluation guideline. Although a total of 3 samples were collected 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data was collected from 3 station(s) with the station code(s): 723BARWDR, 723RICEDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-04-20 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

46168

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 4 of 4 samples exceed the criterion for Dieldrin. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

126246

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 3 samples exceeded the water quality standard for Dieldrin. Data were collected for 3 fish species (1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Dieldrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 3 station(s) with the station code(s): 723BARWDR, 723RICEDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-04-20 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

46181

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Dieldrin. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

126657

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 4 samples exceeded the water quality standard for Dieldrin. Data were collected for 3 fish species (1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Common Carp each composed of 5 fish per composite, 2 composite(s) of Tilapia spp. each composed of 5 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 3 station(s) with the station code(s): 723NRFGDN, 723RI3DRN, 723NRGNDN.

Temporal Representation:

Data for this line of evidence were collected between 2012-10-15 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

5440

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. Four fish fillet sample results could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentration. The 17 fish fillet samples and 19 whole fish samples that were acceptable were generally collected from 5/1986 through 11/2000. Of these total samples, 17 fish fillet samples and 19 whole fish samples collected at 15 locations exceeded the OEHHA Fish Contaminant Goal. At Rose drain exceedances were found in 1 carp fillet composite sample, and 1 mosquitofish whole fish composite sample. At Holtville Main drain exceedances were found in 2 channel catfish fillet composite samples, and 1 carp fillet composite sample. At Central drain exceedances were found in 1 carp fillet composite sample, 1 flathead catfish single fish fillet sample, and 1 sailfin molly whole fish composite sample. At South Central drain exceedances were found in 1 channel catfish single fish fillet sample, 1 carp single fish fillet sample, 1 spiny soft shelled turtle fish composite sample, and 1 sailfin molly whole fish composite sample. At Rice drain 3 exceedances were found in 2 carp fillet composite samples. At Verde drain an exceedance was found in 1 carp single fish fillet sample. At Greeson exceedances were found in 1 carp fillet composite sample, 1 yellow bullhead fillet composite sample, 1 spiny soft shelled turtle fillet composite sample, and 1 mosquitofish whole fish composite sample. At Fig drain exceedances were found in 1 mosquitofish whole fish composite sample, and 3 sailfin molly whole fish composite samples. At Pumice drain exceedances were found in 1 channel catfish fillet composite sample, and 1 carp fillet composite sample. At Mayflower drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Orange drain an exceedance was found in 1 mosquitofish whole fish composite. At Peach drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Tokay drain an exceedance was found in 1 mosquitofish whole fish composite sample. At Barbara Worth drain exceedances were found in 2 mosquitofish whole fish composite samples, and 1 sailfin molly whole fish composite sample. At Warren Drain exceedances were found in 2 mosquitofish whole fish composite samples (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Fish Contaminant Goal of 0.46 ug/kg to protect human health when consuming fish (OEHHA, 2008).

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

5600

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

127164

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 41 samples exceeded the water quality standard for Dieldrin.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 23 monitoring site(s) (723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723CNTDRN, 723HLVLDR, 723MAGDRN, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OLANDR, 723PEACHD, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCNTDR, 723SPRDRN, 723SSDS02, 723SSDS03, 723SSPDRN, 723TI2DRN, 723VERDRN)

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

128140

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Dieldrin.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

125395

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for DPR Surface Water Study 290 Name.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 4 stations. Monitoring site(s): ( 723IPHV10, 723IPMV61, 723IPRC99, 723IPVD69 )

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15.

Environmental Conditions:

QAPP Information:

A QAPP was not required for this data

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 156115, Dieldrin	Region 7
Imperial Valley Drains

LOE ID:

125408

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-11-04.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	156177	Region 7
Imperial Valley Drains

Pollutant:	1-Methylnaphthalene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156177, 1-Methylnaphthalene	Region 7
Imperial Valley Drains

LOE ID:

320055

Pollutant:

1-Methylnaphthalene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156177, 1-Methylnaphthalene	Region 7
Imperial Valley Drains

LOE ID:

320000

Pollutant:

1-Methylnaphthalene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Naphthalene, Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156176	Region 7
Imperial Valley Drains

Pollutant:	1-Methylphenanthrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156176, 1-Methylphenanthrene	Region 7
Imperial Valley Drains

LOE ID:

319267

Pollutant:

1-Methylphenanthrene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Phenanthrene, or 1-Methylphenanthrene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156178	Region 7
Imperial Valley Drains

Pollutant:	2,3,5-Trimethylnaphthalene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156178, 2,3,5-Trimethylnaphthalene	Region 7
Imperial Valley Drains

LOE ID:

320056

Pollutant:

2,3,5-Trimethylnaphthalene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156178, 2,3,5-Trimethylnaphthalene	Region 7
Imperial Valley Drains

LOE ID:

320001

Pollutant:

2,3,5-Trimethylnaphthalene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Naphthalene, Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156179	Region 7
Imperial Valley Drains

Pollutant:	2,6-Dimethylnaphthalene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156179, 2,6-Dimethylnaphthalene	Region 7
Imperial Valley Drains

LOE ID:

320013

Pollutant:

2,6-Dimethylnaphthalene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Naphthalene, Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156179, 2,6-Dimethylnaphthalene	Region 7
Imperial Valley Drains

LOE ID:

319845

Pollutant:

2,6-Dimethylnaphthalene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156146	Region 7
Imperial Valley Drains

Pollutant:	2-Methylnaphthalene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156146, 2-Methylnaphthalene	Region 7
Imperial Valley Drains

LOE ID:

320014

Pollutant:

2-Methylnaphthalene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Naphthalene, Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156146, 2-Methylnaphthalene	Region 7
Imperial Valley Drains

LOE ID:

319846

Pollutant:

2-Methylnaphthalene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156154	Region 7
Imperial Valley Drains

Pollutant:	Acenaphthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156154, Acenaphthene	Region 7
Imperial Valley Drains

LOE ID:

319387

Pollutant:

Acenaphthene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Acenaphthene, pp-DCBP, or Indeno(1,2,3,c,d)Pyrene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156155	Region 7
Imperial Valley Drains

Pollutant:	Acenaphthylene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156155, Acenaphthylene	Region 7
Imperial Valley Drains

LOE ID:

319847

Pollutant:

Acenaphthylene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156155, Acenaphthylene	Region 7
Imperial Valley Drains

LOE ID:

320015

Pollutant:

Acenaphthylene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Naphthalene, Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171953	Region 7
Imperial Valley Drains

Pollutant:	Acetamiprid
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171953, Acetamiprid	Region 7
Imperial Valley Drains

LOE ID:

353938

Pollutant:

Acetamiprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for acetamiprid is the USEPA Aquatic Life Benchmark of 2.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171953, Acetamiprid	Region 7
Imperial Valley Drains

LOE ID:

353936

Pollutant:

Acetamiprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for acetamiprid is the USEPA Aquatic Life Benchmark of 2.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171953, Acetamiprid	Region 7
Imperial Valley Drains

LOE ID:

353937

Pollutant:

Acetamiprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for acetamiprid is the USEPA Aquatic Life Benchmark of 2.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171953, Acetamiprid	Region 7
Imperial Valley Drains

LOE ID:

353933

Pollutant:

Acetamiprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for acetamiprid is the USEPA Aquatic Life Benchmark of 2.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171953, Acetamiprid	Region 7
Imperial Valley Drains

LOE ID:

353942

Pollutant:

Acetamiprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for acetamiprid is the USEPA Aquatic Life Benchmark of 2.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171953, Acetamiprid	Region 7
Imperial Valley Drains

LOE ID:

353934

Pollutant:

Acetamiprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for acetamiprid is the USEPA Aquatic Life Benchmark of 2.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171953, Acetamiprid	Region 7
Imperial Valley Drains

LOE ID:

353941

Pollutant:

Acetamiprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for acetamiprid is the USEPA Aquatic Life Benchmark of 2.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7


DECISION ID	171970	Region 7
Imperial Valley Drains

Pollutant:	Aldicarb
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. 0 of the 5 samples exceed the OBJECTIVE/GUIDELINE/CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 0 of 5 samples exceeded the OBJECTIVE/GUIDELINE/CRITERIA and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 171970, Aldicarb	Region 7
Imperial Valley Drains

LOE ID:

353950

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171970, Aldicarb	Region 7
Imperial Valley Drains

LOE ID:

353945

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171970, Aldicarb	Region 7
Imperial Valley Drains

LOE ID:

353948

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171970, Aldicarb	Region 7
Imperial Valley Drains

LOE ID:

353947

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171970, Aldicarb	Region 7
Imperial Valley Drains

LOE ID:

353949

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	171962	Region 7
Imperial Valley Drains

Pollutant:	Aldicarb sulfone
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. 0 of the 5 samples exceed the OBJECTIVE/GUIDELINE/CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 0 of 5 samples exceeded the OBJECTIVE/GUIDELINE/CRITERIA and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 171962, Aldicarb sulfone	Region 7
Imperial Valley Drains

LOE ID:

353961

Pollutant:

Aldicarb sulfone

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Aldicarb Sulfone is the USEPA Aquatic Life Benchmark of 140 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171962, Aldicarb sulfone	Region 7
Imperial Valley Drains

LOE ID:

353953

Pollutant:

Aldicarb sulfone

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Aldicarb Sulfone is the USEPA Aquatic Life Benchmark of 140 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171962, Aldicarb sulfone	Region 7
Imperial Valley Drains

LOE ID:

353956

Pollutant:

Aldicarb sulfone

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Aldicarb Sulfone is the USEPA Aquatic Life Benchmark of 140 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171962, Aldicarb sulfone	Region 7
Imperial Valley Drains

LOE ID:

353954

Pollutant:

Aldicarb sulfone

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Aldicarb Sulfone is the USEPA Aquatic Life Benchmark of 140 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171962, Aldicarb sulfone	Region 7
Imperial Valley Drains

LOE ID:

353958

Pollutant:

Aldicarb sulfone

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Aldicarb Sulfone is the USEPA Aquatic Life Benchmark of 140 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	171963	Region 7
Imperial Valley Drains

Pollutant:	Aldicarb sulfoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 171963, Aldicarb sulfoxide	Region 7
Imperial Valley Drains

LOE ID:

353972

Pollutant:

Aldicarb sulfoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Aldicarb Sulfoxide is the USEPA Aquatic Life Benchmark of 21.5 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171963, Aldicarb sulfoxide	Region 7
Imperial Valley Drains

LOE ID:

353967

Pollutant:

Aldicarb sulfoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Aldicarb Sulfoxide is the USEPA Aquatic Life Benchmark of 21.5 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171963, Aldicarb sulfoxide	Region 7
Imperial Valley Drains

LOE ID:

353969

Pollutant:

Aldicarb sulfoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Aldicarb Sulfoxide is the USEPA Aquatic Life Benchmark of 21.5 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171963, Aldicarb sulfoxide	Region 7
Imperial Valley Drains

LOE ID:

353965

Pollutant:

Aldicarb sulfoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Aldicarb Sulfoxide is the USEPA Aquatic Life Benchmark of 21.5 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171963, Aldicarb sulfoxide	Region 7
Imperial Valley Drains

LOE ID:

353968

Pollutant:

Aldicarb sulfoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Aldicarb Sulfoxide is the USEPA Aquatic Life Benchmark of 21.5 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156170	Region 7
Imperial Valley Drains

Pollutant:	Aldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156170, Aldrin	Region 7
Imperial Valley Drains

LOE ID:

319633

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Aldrin, Chlorpyrifos, Diazinon, or Toxaphene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156170, Aldrin	Region 7
Imperial Valley Drains

LOE ID:

126344

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 8 samples exceeded the water quality standard for Aldrin. Data were collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Aldrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723PEACHD, 723BARWDR, 723RICEDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156170, Aldrin	Region 7
Imperial Valley Drains

LOE ID:

126541

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 11 samples exceeded the water quality standard for Aldrin. Data were collected for 7 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 7 station(s) with the station code(s): 723BARWDR, 723NRFGDN, 723CNTDRN, 723RI3DRN, 723NRGNDN, 723OLANDR, 723SCNTDR.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156170, Aldrin	Region 7
Imperial Valley Drains

LOE ID:

320033

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156170, Aldrin	Region 7
Imperial Valley Drains

LOE ID:

126961

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Aldrin criterion maximum concentration to protect aquatic life in freshwater is 3 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156170, Aldrin	Region 7
Imperial Valley Drains

LOE ID:

126934

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Aldrin.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Aldrin criterion maximum concentration to protect aquatic life in freshwater is 3 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156170, Aldrin	Region 7
Imperial Valley Drains

LOE ID:

5573

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156170, Aldrin	Region 7
Imperial Valley Drains

LOE ID:

45990

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Aldrin. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156170, Aldrin	Region 7
Imperial Valley Drains

LOE ID:

353973

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The aldrin criterion maximum concentration (expressed as a 1-day average) to protect aquatic life in freshwater is 1.5 ug/L. The criterion of 3 ug/L provided in the California Toxics Rule is an instantaneous maximum concentration and was divided by 2 in order to better represent a criterion maximum concentration (CMC) value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule (2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	159225	Region 7
Imperial Valley Drains

Pollutant:	Alkalinity as CaCO3
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. 15 lines of evidence are available in the administrative record to assess this pollutant. Zero of the 18 samples exceed the guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of 18 samples exceeded the guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

334465

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-10-16 and 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

354001

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-10-16 and 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

353996

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2022-04-26 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

354013

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-10-15 and 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

354011

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2022-04-26 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

353993

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PEACHD (Peach Drain).

Temporal Representation:

The samples were collected between the dates of 2022-04-26 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

353998

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS02 (Salton Sea Drain S2 (Niland 4)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

353997

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

354003

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2022-04-25 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

354005

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2022-04-25 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

353986

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2022-04-25 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

353990

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRFGDN (New River at Fig Drain).

Temporal Representation:

The samples were collected between the dates of 2018-11-14 and 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

354000

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2022-04-26 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

354012

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

The samples were collected between the dates of 2018-11-14 and 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159225, Alkalinity as CaCO3	Region 7
Imperial Valley Drains

LOE ID:

353991

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2022-04-26 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	171949	Region 7
Imperial Valley Drains

Pollutant:	Allethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171949, Allethrin	Region 7
Imperial Valley Drains

LOE ID:

354015

Pollutant:

Allethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Allethrin is the USEPA Aquatic Life Benchmark of 1.05 ug/L for an invertebrate (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	156210	Region 7
Imperial Valley Drains

Pollutant:	Aluminum
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156210, Aluminum	Region 7
Imperial Valley Drains

LOE ID:

354017

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate.

Guideline Reference:

Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156210, Aluminum	Region 7
Imperial Valley Drains

LOE ID:

319499

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Aluminum, Manganese, or Silver for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156210, Aluminum	Region 7
Imperial Valley Drains

LOE ID:

354021

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156210, Aluminum	Region 7
Imperial Valley Drains

LOE ID:

334511

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156198	Region 7
Imperial Valley Drains

Pollutant:	Ametryn
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156198, Ametryn	Region 7
Imperial Valley Drains

LOE ID:

319806

Pollutant:

Ametryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ametryn, Prometryn, Simetryn, or Terbutryn for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156095	Region 7
Imperial Valley Drains

Pollutant:	Anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156095, Anthracene	Region 7
Imperial Valley Drains

LOE ID:

353581

Pollutant:

Anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156095, Anthracene	Region 7
Imperial Valley Drains

LOE ID:

319482

Pollutant:

Anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Anthracene, Benz(a)Anthracene, or Dibenzo(a,h)Anthracene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156095, Anthracene	Region 7
Imperial Valley Drains

LOE ID:

353583

Pollutant:

Anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for anthracene is the probable effect concentration (PEC) of 845 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156096	Region 7
Imperial Valley Drains

Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

5072

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the USFWS Biological Effects Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

United State Fish and Wildlife Service (USFWS) Biological Effect Criteria of 0.25 mg/l for the protection of aquatic life uses (USDOI, 1998).

Guideline Reference:

Guidelines for Interpretation of the Biological Effect of Selected Constituents in Biota, Water, and Sediment. US Department of Interior report.

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

128658

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 57 samples exceeded the water quality standard for Arsenic.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 150 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 33 monitoring site(s) (723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723CENTD2, 723CNTDRN, 723CTD3MA, 723HLVLDR, 723MAGDRN, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OASISD, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PEACHD, 723PMLEOD, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCENTD, 723SCNTDR, 723SPRDRN, 723SSDS02, 723SSDS03, 723SSPDRN, 723TI2DRN, 723UADGUN, 723VERDED, 723VERDRN)

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

45991

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Arsenic. Seventeen composites (1 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Seventeen samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for arsenic in fish tissue is 0.0034 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. It is assumed that 10% of the total arsenic is present as inorganic arsenic. This constituent is a carcinogen therefore the risk level is set to one in a million.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

5545

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-three fish fillet samples and 24 whole fish samples were taken at 19 locations in Imperial Valley drains. Nineteen fish fillet and 16 whole fish sample results could not be used in this assessment because the consituent was not analyzed in the sample. The 4 fish fillet samples and 8 whole fish samples that were acceptable were generally collected from 8/1990 through 11/2000 at nine locations. Of these total samples, none exceeded the OEHHA Screening Value (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 1 mg/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

321176

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

320034

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

353602

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 3 samples exceeded the evaluation guideline for Arsenic .

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-08 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

353603

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-10 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

353596

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRFGDN (New River at Fig Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

353597

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

354065

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

354067

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

333477

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for arsenic is the probable effect concentration (PEC) of 33 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-09 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156096, Arsenic	Region 7
Imperial Valley Drains

LOE ID:

334598

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7


DECISION ID	171956	Region 7
Imperial Valley Drains

Pollutant:	Atrazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 171956, Atrazine	Region 7
Imperial Valley Drains

LOE ID:

354073

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of < 1 ug/L for a nonvascular plant (acute). The benchmark was derived from a 'less-than' value (for example, <1,500) and may underestimate toxicity.

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2015-03-24 and 2015-03-24

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171956, Atrazine	Region 7
Imperial Valley Drains

LOE ID:

354074

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2015-03-24 and 2015-03-24

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171956, Atrazine	Region 7
Imperial Valley Drains

LOE ID:

354077

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2015-03-24 and 2015-03-24

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156202	Region 7
Imperial Valley Drains

Pollutant:	Atroton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156202, Atroton	Region 7
Imperial Valley Drains

LOE ID:

319465

Pollutant:

Atroton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Atroton, Prometon, or Secbumeton for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156191	Region 7
Imperial Valley Drains

Pollutant:	Azinphos, Ethyl (Ethyl Guthion)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156191, Azinphos, Ethyl (Ethyl Guthion)	Region 7
Imperial Valley Drains

LOE ID:

319271

Pollutant:

Azinphos, Ethyl (Ethyl Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Azinphos, methyl, or Azinphos, ethyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156123	Region 7
Imperial Valley Drains

Pollutant:	Azinphos-methyl (Guthion)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156123, Azinphos-methyl (Guthion)	Region 7
Imperial Valley Drains

LOE ID:

319272

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Azinphos, methyl, or Azinphos, ethyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156123, Azinphos-methyl (Guthion)	Region 7
Imperial Valley Drains

LOE ID:

128925

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The National Recommended Water Quality Criteria for Azinphos Methyl (Guthion) expressed as a 4-day average for the protection of freshwater aquatic life is a maximum of 0.01 ug/l.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-07 to 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	159232	Region 7
Imperial Valley Drains

Pollutant:	Bensulide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159232, Bensulide	Region 7
Imperial Valley Drains

LOE ID:

354089

Pollutant:

Bensulide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Bensulide.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Bensulide is the USEPA Aquatic Life Benchmark of 11 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159232, Bensulide	Region 7
Imperial Valley Drains

LOE ID:

354087

Pollutant:

Bensulide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Bensulide is the USEPA Aquatic Life Benchmark of 11 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159232, Bensulide	Region 7
Imperial Valley Drains

LOE ID:

354090

Pollutant:

Bensulide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Bensulide is the USEPA Aquatic Life Benchmark of 11 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159232, Bensulide	Region 7
Imperial Valley Drains

LOE ID:

354093

Pollutant:

Bensulide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Bensulide is the USEPA Aquatic Life Benchmark of 11 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159232, Bensulide	Region 7
Imperial Valley Drains

LOE ID:

354099

Pollutant:

Bensulide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Bensulide is the USEPA Aquatic Life Benchmark of 11 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159232, Bensulide	Region 7
Imperial Valley Drains

LOE ID:

334637

Pollutant:

Bensulide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Bensulide is the USEPA Aquatic Life Benchmark of 11 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159232, Bensulide	Region 7
Imperial Valley Drains

LOE ID:

354088

Pollutant:

Bensulide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Bensulide is the USEPA Aquatic Life Benchmark of 11 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159232, Bensulide	Region 7
Imperial Valley Drains

LOE ID:

354092

Pollutant:

Bensulide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Bensulide is the USEPA Aquatic Life Benchmark of 11 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159232, Bensulide	Region 7
Imperial Valley Drains

LOE ID:

354098

Pollutant:

Bensulide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Bensulide is the USEPA Aquatic Life Benchmark of 11 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159232, Bensulide	Region 7
Imperial Valley Drains

LOE ID:

354083

Pollutant:

Bensulide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Bensulide is the USEPA Aquatic Life Benchmark of 11 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156098	Region 7
Imperial Valley Drains

Pollutant:	Benzo(a)anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156098, Benzo(a)anthracene	Region 7
Imperial Valley Drains

LOE ID:

353608

Pollutant:

Benzo(a)anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156098, Benzo(a)anthracene	Region 7
Imperial Valley Drains

LOE ID:

319483

Pollutant:

Benzo(a)anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Anthracene, Benz(a)Anthracene, or Dibenzo(a,h)Anthracene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156098, Benzo(a)anthracene	Region 7
Imperial Valley Drains

LOE ID:

321177

Pollutant:

Benzo(a)anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156098, Benzo(a)anthracene	Region 7
Imperial Valley Drains

LOE ID:

353606

Pollutant:

Benzo(a)anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for benz[a]anthrazene is the probable effect concentration (PEC) of 1050 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	156097	Region 7
Imperial Valley Drains

Pollutant:	Benzo(a)pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156097, Benzo(a)pyrene	Region 7
Imperial Valley Drains

LOE ID:

353613

Pollutant:

Benzo(a)pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156097, Benzo(a)pyrene	Region 7
Imperial Valley Drains

LOE ID:

4963

Pollutant:

Benzo(a)pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were generally collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Consensus Based Sediment Quality Guideline Probable Effects Concentration (PEC) of 1450 ug/kg for the protection of freshwater organisms to toxic effects (Macdonald et al, 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Sediment samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected at each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156097, Benzo(a)pyrene	Region 7
Imperial Valley Drains

LOE ID:

353612

Pollutant:

Benzo(a)pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for benzo[a]pyrene is the probable effect concentration (PEC) of 1450 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156197	Region 7
Imperial Valley Drains

Pollutant:	Benzo(e)Pyrene (4,5-benzopyrene)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156197, Benzo(e)Pyrene (4,5-benzopyrene)	Region 7
Imperial Valley Drains

LOE ID:

319791

Pollutant:

Benzo(e)Pyrene (4,5-benzopyrene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, Biphenyl, or Terbufos for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156197, Benzo(e)Pyrene (4,5-benzopyrene)	Region 7
Imperial Valley Drains

LOE ID:

319469

Pollutant:

Benzo(e)Pyrene (4,5-benzopyrene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, or Biphenyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156099	Region 7
Imperial Valley Drains

Pollutant:	Benzo[b]fluoranthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156099, Benzo[b]fluoranthene	Region 7
Imperial Valley Drains

LOE ID:

319320

Pollutant:

Benzo[b]fluoranthene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Benzo(b)Fluoranthene, or Benzo(k)Fluoranthene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156100	Region 7
Imperial Valley Drains

Pollutant:	Benzo[g,h,i]perylene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156100, Benzo[g,h,i]perylene	Region 7
Imperial Valley Drains

LOE ID:

319470

Pollutant:

Benzo[g,h,i]perylene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, or Biphenyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156100, Benzo[g,h,i]perylene	Region 7
Imperial Valley Drains

LOE ID:

319807

Pollutant:

Benzo[g,h,i]perylene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, Biphenyl, or Terbufos for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156101	Region 7
Imperial Valley Drains

Pollutant:	Benzo[k]fluoranthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156101, Benzo[k]fluoranthene	Region 7
Imperial Valley Drains

LOE ID:

319321

Pollutant:

Benzo[k]fluoranthene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Benzo(b)Fluoranthene, or Benzo(k)Fluoranthene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156102	Region 7
Imperial Valley Drains

Pollutant:	Biphenyl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156102, Biphenyl	Region 7
Imperial Valley Drains

LOE ID:

319481

Pollutant:

Biphenyl

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, or Biphenyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156102, Biphenyl	Region 7
Imperial Valley Drains

LOE ID:

319808

Pollutant:

Biphenyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, Biphenyl, or Terbufos for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156171	Region 7
Imperial Valley Drains

Pollutant:	Bolstar
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156171, Bolstar	Region 7
Imperial Valley Drains

LOE ID:

320851

Pollutant:

Bolstar

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156103	Region 7
Imperial Valley Drains

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

45992

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Cadmium. Seventeen composites (1 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for cadmium in fish tissue is 2.2 ppm. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

127093

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 55 samples exceeded the water quality standard for Cadmium.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 32 monitoring site(s) (723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723CENTD2, 723CNTDRN, 723CTD3MA, 723HLVLDR, 723MAGDRN, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OASISD, 723OLANDR, 723OSAGED, 723PAMPAD, 723PEACHD, 723PMLEOD, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCENTD, 723SCNTDR, 723SPRDRN, 723SSDS02, 723SSDS03, 723SSPDRN, 723TI2DRN, 723UADGUN, 723VERDED, 723VERDRN)

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

333516

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-09 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

334667

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.2 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

354136

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

353621

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

353637

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-08 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

319382

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five water quality samples were generally collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) Hardness Dependent Criterion Maximum Concentrations (CMCs) for the protection of freshwater aquatic life uses were used for the following constituents: Cadmium, Lead, Nickel, and Zinc (USEPA, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

321178

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

5546

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-three fish fillet samples and 24 whole fish samples were taken at 19 locations in Imperial Valley drains. Twenty-two fish fillet and 16 whole fish sample results could not be used in this assessment because the consituent was not analyzed in the sample. The 1 fillet and 8 whole fish samples that were acceptable were generally collected from 8/1990 through 11/2000 at seven locations. Of these total samples, none exceeded the OEHHA Screening Value (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 3 mg/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

353632

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRFGDN (New River at Fig Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

354137

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156103, Cadmium	Region 7
Imperial Valley Drains

LOE ID:

353641

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for cadmium is the probable effect concentration (PEC) of 4.98 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-10 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7


DECISION ID	171957	Region 7
Imperial Valley Drains

Pollutant:	Carbaryl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 171957, Carbaryl	Region 7
Imperial Valley Drains

LOE ID:

354154

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA National Recommended Aquatic Life criteria pursuant to Section 304(a) of the Clean Water Act for Carbaryl is 2.1 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171957, Carbaryl	Region 7
Imperial Valley Drains

LOE ID:

354152

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA National Recommended Aquatic Life criteria pursuant to Section 304(a) of the Clean Water Act for Carbaryl is 2.1 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171957, Carbaryl	Region 7
Imperial Valley Drains

LOE ID:

354151

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA National Recommended Aquatic Life criteria pursuant to Section 304(a) of the Clean Water Act for Carbaryl is 2.1 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171957, Carbaryl	Region 7
Imperial Valley Drains

LOE ID:

354153

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA National Recommended Aquatic Life criteria pursuant to Section 304(a) of the Clean Water Act for Carbaryl is 2.1 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171957, Carbaryl	Region 7
Imperial Valley Drains

LOE ID:

354155

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA National Recommended Aquatic Life criteria pursuant to Section 304(a) of the Clean Water Act for Carbaryl is 2.1 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691


DECISION ID	171958	Region 7
Imperial Valley Drains

Pollutant:	Carbofuran
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. 0 of the 5 samples exceed the OBJECTIVE/GUIDELINE/CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 0 of 5 samples exceeded the OBJECTIVE/GUIDELINE/CRITERIA and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 171958, Carbofuran	Region 7
Imperial Valley Drains

LOE ID:

354165

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for carbofuran is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertibrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171958, Carbofuran	Region 7
Imperial Valley Drains

LOE ID:

354160

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for carbofuran is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertibrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171958, Carbofuran	Region 7
Imperial Valley Drains

LOE ID:

354161

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for carbofuran is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertibrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171958, Carbofuran	Region 7
Imperial Valley Drains

LOE ID:

354163

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for carbofuran is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertibrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171958, Carbofuran	Region 7
Imperial Valley Drains

LOE ID:

354159

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for carbofuran is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertibrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156180	Region 7
Imperial Valley Drains

Pollutant:	Carbophenothion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156180, Carbophenothion	Region 7
Imperial Valley Drains

LOE ID:

320901

Pollutant:

Carbophenothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156163	Region 7
Imperial Valley Drains

Pollutant:	Chlorfenvinphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156163, Chlorfenvinphos	Region 7
Imperial Valley Drains

LOE ID:

320706

Pollutant:

Chlorfenvinphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	159215	Region 7
Imperial Valley Drains

Pollutant:	Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Three of the three samples exceed the threshold. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Three of the three samples exceed the threshold and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159215, Chloride	Region 7
Imperial Valley Drains

LOE ID:

334726

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2020-01-08 and 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159215, Chloride	Region 7
Imperial Valley Drains

LOE ID:

354173

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159215, Chloride	Region 7
Imperial Valley Drains

LOE ID:

354170

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159215, Chloride	Region 7
Imperial Valley Drains

LOE ID:

354182

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2020-01-14 and 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159215, Chloride	Region 7
Imperial Valley Drains

LOE ID:

354180

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS02 (Salton Sea Drain S2 (Niland 4)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159215, Chloride	Region 7
Imperial Valley Drains

LOE ID:

129026

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the water quality standard for Chloride.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (728SSDS01)

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	171959	Region 7
Imperial Valley Drains

Pollutant:	Chlorothalonil
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 171959, Chlorothalonil	Region 7
Imperial Valley Drains

LOE ID:

354191

Pollutant:

Chlorothalonil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chlorothalonil is the USEPA Aquatic Life Benchmark of 0.6 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2013-03-05 and 2013-03-05

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171959, Chlorothalonil	Region 7
Imperial Valley Drains

LOE ID:

354187

Pollutant:

Chlorothalonil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chlorothalonil is the USEPA Aquatic Life Benchmark of 0.6 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-03-05 and 2014-03-05

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171959, Chlorothalonil	Region 7
Imperial Valley Drains

LOE ID:

354190

Pollutant:

Chlorothalonil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chlorothalonil is the USEPA Aquatic Life Benchmark of 0.6 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2013-03-05 and 2013-03-05

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171959, Chlorothalonil	Region 7
Imperial Valley Drains

LOE ID:

354186

Pollutant:

Chlorothalonil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chlorothalonil is the USEPA Aquatic Life Benchmark of 0.6 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2013-03-05 and 2013-03-05

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156207	Region 7
Imperial Valley Drains

Pollutant:	Chlorpyrifos, methyl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). LOE Removal(s): 29876; LOE Replacement(s): 320707 The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156207, Chlorpyrifos, methyl	Region 7
Imperial Valley Drains

LOE ID:

354237

Pollutant:

Chlorpyrifos, methyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Chlorpyrifos Methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156207, Chlorpyrifos, methyl	Region 7
Imperial Valley Drains

LOE ID:

354241

Pollutant:

Chlorpyrifos, methyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Chlorpyrifos Methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156207, Chlorpyrifos, methyl	Region 7
Imperial Valley Drains

LOE ID:

354244

Pollutant:

Chlorpyrifos, methyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Chlorpyrifos Methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156207, Chlorpyrifos, methyl	Region 7
Imperial Valley Drains

LOE ID:

320707

Pollutant:

Chlorpyrifos, methyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156207, Chlorpyrifos, methyl	Region 7
Imperial Valley Drains

LOE ID:

129053

Pollutant:

Chlorpyrifos, methyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 72 samples exceeded the water quality standard for Chlorpyrifos Methyl.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Chlorpyrifos Methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 49 monitoring site(s) (723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723BDRAIN, 723CENTD2, 723CENTD3, 723CNTDRN, 723CTD3MA, 723EDRAIN, 723ELML6D, 723HLVLDR, 723KDRAIN, 723MAGDRN, 723MARIGD, 723MCALD1, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OASISD, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PEACHD, 723PMLEOD, 723QLATDR, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCENTD, 723SCNTDR, 723SPRDRN, 723SPRUCD, 723SSDS02, 723SSDS03, 723SSPDRN, 723THIS5D, 723TI2DRN, 723TRI12D, 723UADCMC, 723UADGUN, 723UADSPC, 723VAIL7D, 723VAL2AD, 723VERDED, 723VERDRN, 723WILDCD)

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	156209	Region 7
Imperial Valley Drains

Pollutant:	Chromium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156209, Chromium	Region 7
Imperial Valley Drains

LOE ID:

354250

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 180 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-10-15 and 2019-10-15

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156209, Chromium	Region 7
Imperial Valley Drains

LOE ID:

320985

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156209, Chromium	Region 7
Imperial Valley Drains

LOE ID:

353662

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156209, Chromium	Region 7
Imperial Valley Drains

LOE ID:

353659

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-10 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156209, Chromium	Region 7
Imperial Valley Drains

LOE ID:

354247

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 180 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156209, Chromium	Region 7
Imperial Valley Drains

LOE ID:

334796

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 180 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156209, Chromium	Region 7
Imperial Valley Drains

LOE ID:

333555

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-09 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156209, Chromium	Region 7
Imperial Valley Drains

LOE ID:

353665

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-08 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156209, Chromium	Region 7
Imperial Valley Drains

LOE ID:

353650

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chromium is the probable effect concentration (PEC) of 111 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRFGDN (New River at Fig Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156209, Chromium	Region 7
Imperial Valley Drains

LOE ID:

319307

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):


DECISION ID	69929	Region 7
Imperial Valley Drains

Pollutant:	Chromium (total)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceed the objectives. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 69929, Chromium (total)	Region 7
Imperial Valley Drains

LOE ID:

127595

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 56 samples exceeded the water quality standard for Chromium.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	156106	Region 7
Imperial Valley Drains

Pollutant:	Chrysene (C1-C4)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156106, Chrysene (C1-C4)	Region 7
Imperial Valley Drains

LOE ID:

353675

Pollutant:

Chrysene (C1-C4)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-14 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156106, Chrysene (C1-C4)	Region 7
Imperial Valley Drains

LOE ID:

353670

Pollutant:

Chrysene (C1-C4)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156106, Chrysene (C1-C4)	Region 7
Imperial Valley Drains

LOE ID:

353671

Pollutant:

Chrysene (C1-C4)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for chrysene is the probable effect concentration (PEC) of 1290 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156106, Chrysene (C1-C4)	Region 7
Imperial Valley Drains

LOE ID:

320986

Pollutant:

Chrysene (C1-C4)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	170780	Region 7
Imperial Valley Drains

Pollutant:	Cinerin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs 128113 and 127353 are reassessed and replaced by LOE 355456. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 170780, Cinerin	Region 7
Imperial Valley Drains

LOE ID:

355456

Pollutant:

Cinerin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for cinerin is the USEPA Aquatic Life Benchmark of 0.04 ug/L for freshwater invertebrates (chronic) and is the sum of cinerin-1 and cinerin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156172	Region 7
Imperial Valley Drains

Pollutant:	Ciodrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156172, Ciodrin	Region 7
Imperial Valley Drains

LOE ID:

320864

Pollutant:

Ciodrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171973	Region 7
Imperial Valley Drains

Pollutant:	Clothianidin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 171973, Clothianidin	Region 7
Imperial Valley Drains

LOE ID:

354267

Pollutant:

Clothianidin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Clothianidin is the USEPA Aquatic Life Benchmark of 1.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171973, Clothianidin	Region 7
Imperial Valley Drains

LOE ID:

354261

Pollutant:

Clothianidin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Clothianidin is the USEPA Aquatic Life Benchmark of 1.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171973, Clothianidin	Region 7
Imperial Valley Drains

LOE ID:

354259

Pollutant:

Clothianidin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Clothianidin is the USEPA Aquatic Life Benchmark of 1.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171973, Clothianidin	Region 7
Imperial Valley Drains

LOE ID:

354262

Pollutant:

Clothianidin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Clothianidin is the USEPA Aquatic Life Benchmark of 1.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171973, Clothianidin	Region 7
Imperial Valley Drains

LOE ID:

354265

Pollutant:

Clothianidin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Clothianidin is the USEPA Aquatic Life Benchmark of 1.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171973, Clothianidin	Region 7
Imperial Valley Drains

LOE ID:

354266

Pollutant:

Clothianidin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Clothianidin is the USEPA Aquatic Life Benchmark of 1.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171973, Clothianidin	Region 7
Imperial Valley Drains

LOE ID:

354264

Pollutant:

Clothianidin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Clothianidin is the USEPA Aquatic Life Benchmark of 1.1 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156107	Region 7
Imperial Valley Drains

Pollutant:	Copper
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

4944

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were generally collected and analyzed twice, in May and October of 2002 at 3 Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule Hardness Dependent Criterion Maximum Concentration (CMC) for the protection of freshwater aquatic life uses (USEPA, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

5073

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the USFWS Biological Effects Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

United State Fish and Wildlife Service (USFWS) Biological Effects Criteria of 15 mg/l for the protection of aquatic life uses (USDOI, 1998).

Guideline Reference:

Guidelines for Interpretation of the Biological Effect of Selected Constituents in Biota, Water, and Sediment. US Department of Interior report.

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

127120

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

320987

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

353696

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-08 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

353676

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-10 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

354279

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

353693

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRFGDN (New River at Fig Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

353682

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

354269

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

334863

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156107, Copper	Region 7
Imperial Valley Drains

LOE ID:

333596

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for copper is the probable effect concentration (PEC) of 149 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-09 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.


DECISION ID	102629	Region 7
Imperial Valley Drains

Pollutant:	Coumaphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1, a single line(s) of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of zero samples exceed the USEPA Aquatic Life Benchmark for an invertebrate (chronic). Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5 Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of zero samples exceed the USEPA Aquatic Life Benchmark for an invertebrate (chronic). Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5 This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 102629, Coumaphos	Region 7
Imperial Valley Drains

LOE ID:

127998

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Coumaphos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-07 to 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	156164	Region 7
Imperial Valley Drains

Pollutant:	Cuomaphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156164, Cuomaphos	Region 7
Imperial Valley Drains

LOE ID:

320708

Pollutant:

Cuomaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	159228	Region 7
Imperial Valley Drains

Pollutant:	Cyfluthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.6 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355519

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The chronic criterion for cyfluthrin is 0.2 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of cyfluthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

351681

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355515

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354293

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354301

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355500

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355482

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354289

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355496

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354303

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355469

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355507

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355477

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355485

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355489

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354300

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355494

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355499

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354309

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355506

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723BDRAIN (B Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354291

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354296

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355492

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354286

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355483

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354295

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354302

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355513

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355520

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355464

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355467

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

354287

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355466

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355474

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355518

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355470

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

353700

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin (Amweg et al., 2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WRMWDD (Wormwood Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

353701

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MTSIGD (Mount Signal Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

353698

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355484

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355498

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

125821

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 25 samples exceeded the evaluation guideline for Cyfluthrin, total. Although a total of 26 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 26 (Station Codes: 723BDRAIN, 723CENTD2, 723CENTD3, 723CTD3MA, 723EDRAIN, 723ELML6D, 723KDRAIN, 723MARIGD, 723MCALD1, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PMLEOD, 723QLATDR, 723SCENTD, 723SPRUCD, 723THIS5D, 723TRI12D, 723UADCMC, 723UADGUN, 723UADSPC, 723VAIL7D, 723VAL2AD, 723VERDED, 723WILDCD).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

334885

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159228, Cyfluthrin	Region 7
Imperial Valley Drains

LOE ID:

355472

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.


DECISION ID	159229	Region 7
Imperial Valley Drains

Pollutant:	Cyhalothrin, Lambda
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.6 of the Listing Policy. One sample exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355939

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The chronic criterion for lambda-cyhalothrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of lambda-cyhalothrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355948

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355919

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355923

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354774

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355938

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355912

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354750

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354773

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355926

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355901

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355907

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723BDRAIN (B Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355909

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355943

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354755

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

353705

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin (Amweg et al., 2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MTSIGD (Mount Signal Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355934

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355931

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355937

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355928

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354768

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

125526

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 1 of the 24 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda-. Although a total of 25 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 25 (Station Codes: 723BDRAIN, 723CENTD2, 723CENTD3, 723CTD3MA, 723EDRAIN, 723ELML6D, 723KDRAIN, 723MARIGD, 723MCALD1, 723OLANDR, 723OSAGED, 723PAMPAD, 723PMLEOD, 723QLATDR, 723SCENTD, 723SPRUCD, 723THIS5D, 723TRI12D, 723UADCMC, 723UADGUN, 723UADSPC, 723VAIL7D, 723VAL2AD, 723VERDED, 723WILDCD).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

335427

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

351842

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355940

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355910

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355922

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

353703

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354759

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354765

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Lambda-cyhalothrin. Although a total of 3 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site (723IPVD69).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

353704

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WRMWDD (Wormwood Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355927

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355932

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355947

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355905

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354751

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354754

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354767

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355936

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355946

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355929

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

355914

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354758

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159229, Cyhalothrin, Lambda	Region 7
Imperial Valley Drains

LOE ID:

354763

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 4 of the 4 samples exceeded the water quality threshold for Lambda-cyhalothrin. Although a total of 7 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site (723ST1252).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691


DECISION ID	172119	Region 7
Imperial Valley Drains

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 172119, DDD (Dichlorodiphenyldichloroethane)	Region 7
Imperial Valley Drains

LOE ID:

353712

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for the sum of DDD is the probable effect concentration (PEC) of 28 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.


DECISION ID	156108	Region 7
Imperial Valley Drains

Pollutant:	Dacthal
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). LOE Removal(s): 29878, 30057; LOE Replacement(s): 320865, 319453 The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156108, Dacthal	Region 7
Imperial Valley Drains

LOE ID:

127379

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 32 samples exceeded the water quality standard for Dacthal.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Dacthal is the USEPA Aquatic Life Benchmark of > 11000 ug/L for a nonvascular plant (acute) and vascular plant (acute). The benchmark was derived from a 'greater-than' value (for example, > 265,000) and may overestimate toxicity.

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-16

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156108, Dacthal	Region 7
Imperial Valley Drains

LOE ID:

319453

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Dacthal, Mirex, or Oxadiazon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156108, Dacthal	Region 7
Imperial Valley Drains

LOE ID:

128754

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Dacthal.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156108, Dacthal	Region 7
Imperial Valley Drains

LOE ID:

320865

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	169360	Region 7
Imperial Valley Drains

Pollutant:	Deltamethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355632

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355640

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355595

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355596

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355597

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355598

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355604

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355613

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

351731

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

348845

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program Â

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357546

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357541

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723KDRAIN (K Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357567

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PMLEOD (Pomelo Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357547

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357559

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SCENTD (South Central Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357552

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357565

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723OSAGED (Osage Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-04 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357575

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PAM115 (Pampas Drain near 115).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357569

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MARIGD (Marigold Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357555

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CENTD3 (Central Drain Three).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357574

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PAMPAD (Pampas Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357572

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723EDRAIN (E Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357543

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357566

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CENTD2 (Central Drain Two).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357542

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WILDCD (Wildcat Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357550

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VERDED (Verde Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357562

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723OLANDR (Oleander Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-04 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357556

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723BDRAIN (B Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357570

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357540

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VAIL7D (Vail Seven Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357577

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357545

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357576

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MCALD1 (McCall Drain One).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

357573

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723THIS5D (Thistle Five Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355637

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355642

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355624

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355634

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355590

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355607

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355620

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

354365

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355622

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355638

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355643

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355619

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

353727

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355625

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

354368

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355603

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

353726

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WRMWDD (Wormwood Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

354363

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

354366

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355623

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BDRAIN (B Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355608

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355635

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355599

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

355600

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169360, Deltamethrin	Region 7
Imperial Valley Drains

LOE ID:

353730

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MTSIGD (Mount Signal Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156110	Region 7
Imperial Valley Drains

Pollutant:	Demeton s
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156110, Demeton s	Region 7
Imperial Valley Drains

LOE ID:

320866

Pollutant:

Demeton s

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171948	Region 7
Imperial Valley Drains

Pollutant:	Desethyl-Atrazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171948, Desethyl-Atrazine	Region 7
Imperial Valley Drains

LOE ID:

354378

Pollutant:

Desethyl-Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for desethyl-atrazine is the USEPA Aquatic Life Benchmark of 1000 ug/L for a nonvascular plant (acute) for triazine DEA degradate.

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2015-03-24 and 2015-03-24

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171948, Desethyl-Atrazine	Region 7
Imperial Valley Drains

LOE ID:

354381

Pollutant:

Desethyl-Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for desethyl-atrazine is the USEPA Aquatic Life Benchmark of 1000 ug/L for a nonvascular plant (acute) for triazine DEA degradate.

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2015-03-24 and 2015-03-24

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171948, Desethyl-Atrazine	Region 7
Imperial Valley Drains

LOE ID:

354377

Pollutant:

Desethyl-Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for desethyl-atrazine is the USEPA Aquatic Life Benchmark of 1000 ug/L for a nonvascular plant (acute) for triazine DEA degradate.

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2015-03-24 and 2015-03-24

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156111	Region 7
Imperial Valley Drains

Pollutant:	Diazinon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. The number of measured exceedances is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicant pollutants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that this water segment-pollutant combination should not be placed on the CWA section 303(d) List. Refer to the lines of evidence in this fact sheet for the data and information, sample counts and exceedances, quality assurance documentation, beneficial uses, and water quality objectives or numeric evaluation guidelines relied upon for this decision.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354408

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354387

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354407

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354383

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

46167

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Diazinon. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for diazinon in fish tissue is 1,500 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

5532

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 300 ug/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

127143

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 3 of 72 samples exceeded the water quality standard for Diazinon.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

319647

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Aldrin, Chlorpyrifos, Diazinon, or Toxaphene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354415

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354409

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354396

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354412

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354397

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354403

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354395

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354404

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

354414

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

334998

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156111, Diazinon	Region 7
Imperial Valley Drains

LOE ID:

4952

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains. Of these total samples, none exceeded the CDFG Hazardous Assessment Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

California Department of Fish and Game (CDFG) Hazardous Assessment Criteria of 0.16 ug/l for the protection of aquatic life uses (Siepmann and Finlayson, 2000).

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

Quality Assurance and Quality Control for the sampling and analysis of this study was conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156112	Region 7
Imperial Valley Drains

Pollutant:	Dibenz[a,h]anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156112, Dibenz[a,h]anthracene	Region 7
Imperial Valley Drains

LOE ID:

319484

Pollutant:

Dibenz[a,h]anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Anthracene, Benz(a)Anthracene, or Dibenzo(a,h)Anthracene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156181	Region 7
Imperial Valley Drains

Pollutant:	Dichlofenthion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156181, Dichlofenthion	Region 7
Imperial Valley Drains

LOE ID:

320902

Pollutant:

Dichlofenthion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156113	Region 7
Imperial Valley Drains

Pollutant:	Dichlorobenzophenone
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156113, Dichlorobenzophenone	Region 7
Imperial Valley Drains

LOE ID:

319400

Pollutant:

Dichlorobenzophenone

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Acenaphthene, pp-DCBP, or Indeno(1,2,3,c,d)Pyrene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156114	Region 7
Imperial Valley Drains

Pollutant:	Dichlorvos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156114, Dichlorvos	Region 7
Imperial Valley Drains

LOE ID:

354423

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156114, Dichlorvos	Region 7
Imperial Valley Drains

LOE ID:

354432

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156114, Dichlorvos	Region 7
Imperial Valley Drains

LOE ID:

320878

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156114, Dichlorvos	Region 7
Imperial Valley Drains

LOE ID:

354430

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156114, Dichlorvos	Region 7
Imperial Valley Drains

LOE ID:

354424

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156114, Dichlorvos	Region 7
Imperial Valley Drains

LOE ID:

354431

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156114, Dichlorvos	Region 7
Imperial Valley Drains

LOE ID:

354427

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156165	Region 7
Imperial Valley Drains

Pollutant:	Dicrotophos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156165, Dicrotophos	Region 7
Imperial Valley Drains

LOE ID:

320709

Pollutant:

Dicrotophos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156158	Region 7
Imperial Valley Drains

Pollutant:	Dimethoate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). LOE Removal(s): 29878; LOE Replacement(s): 320879 The number of measured exceedances is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicant pollutants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that this water segment-pollutant combination should not be placed on the CWA section 303(d) List. Refer to the lines of evidence in this fact sheet for the data and information, sample counts and exceedances, quality assurance documentation, beneficial uses, and water quality objectives or numeric evaluation guidelines relied upon for this decision.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

354456

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

354467

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

320879

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

128135

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 2 of 44 samples exceeded the water quality standard for Dimethoate.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

354450

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 1 of 8 samples exceeded the water quality threshold for Dimethoate.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

335050

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

354473

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

354458

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

354465

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

354469

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

354457

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

354472

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 1 of 7 samples exceeded the water quality threshold for Dimethoate.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156158, Dimethoate	Region 7
Imperial Valley Drains

LOE ID:

354464

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	171954	Region 7
Imperial Valley Drains

Pollutant:	Dinotefuran
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171954, Dinotefuran	Region 7
Imperial Valley Drains

LOE ID:

354475

Pollutant:

Dinotefuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Dinotefuran is the USEPA Aquatic Life Benchmark of > 6360 ug/L for a fish (chronic). The benchmark was derived from a 'greater-than' value (for example, > 265,000) and may overestimate toxicity.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171954, Dinotefuran	Region 7
Imperial Valley Drains

LOE ID:

354482

Pollutant:

Dinotefuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171954, Dinotefuran	Region 7
Imperial Valley Drains

LOE ID:

354481

Pollutant:

Dinotefuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171954, Dinotefuran	Region 7
Imperial Valley Drains

LOE ID:

354477

Pollutant:

Dinotefuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171954, Dinotefuran	Region 7
Imperial Valley Drains

LOE ID:

354484

Pollutant:

Dinotefuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171954, Dinotefuran	Region 7
Imperial Valley Drains

LOE ID:

354483

Pollutant:

Dinotefuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171954, Dinotefuran	Region 7
Imperial Valley Drains

LOE ID:

354479

Pollutant:

Dinotefuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156208	Region 7
Imperial Valley Drains

Pollutant:	Dioxathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156208, Dioxathion	Region 7
Imperial Valley Drains

LOE ID:

320903

Pollutant:

Dioxathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156117	Region 7
Imperial Valley Drains

Pollutant:	Dyfonate (Fonofos or Fonophos)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156117, Dyfonate (Fonofos or Fonophos)	Region 7
Imperial Valley Drains

LOE ID:

354665

Pollutant:

Dyfonate (Fonofos or Fonophos)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fonofos is the maximum acceptable toxicant concentration (MATC) of 0.45 ug/L. The MATC is calculated as the geometric mean of the lowest observed effect concentration (LOEC) of 0.64 ug/L and the no observed effect concentration (NOEC) of 0.31 ug/L, as determined in a 21 day toxicity study with the water flea, Daphnia magna. Threshold values (LOEC and NOEC) are from USEPA Office of Pesticide Programs Ecotoxicity database.

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156117, Dyfonate (Fonofos or Fonophos)	Region 7
Imperial Valley Drains

LOE ID:

354669

Pollutant:

Dyfonate (Fonofos or Fonophos)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156117, Dyfonate (Fonofos or Fonophos)	Region 7
Imperial Valley Drains

LOE ID:

354667

Pollutant:

Dyfonate (Fonofos or Fonophos)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156117, Dyfonate (Fonofos or Fonophos)	Region 7
Imperial Valley Drains

LOE ID:

320720

Pollutant:

Dyfonate (Fonofos or Fonophos)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156118	Region 7
Imperial Valley Drains

Pollutant:	Endosulfan sulfate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s).

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156118, Endosulfan sulfate	Region 7
Imperial Valley Drains

LOE ID:

319496

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Endosulfan 1, Endosulfan 2, or Endosulfan Sulfate for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156119	Region 7
Imperial Valley Drains

Pollutant:	Endrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

127347

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Endrin.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

126524

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 7 samples exceeded the water quality standard for Endrin. Data were collected for 6 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for endrin in fish tissue is 660 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; USEPA, 2000)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723BARWDR, 723PEACHD, 723RICEDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

126440

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 10 samples exceeded the water quality standard for Endrin. Data were collected for 6 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Data was collected from 7 station(s) with the station code(s): 723NRGNDN, 723NRFGDN, 723RI3DRN, 723SCNTDR, 723CNTDRN, 723BARWDR, 723OLANDR.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

46184

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Endrin. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

353738

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for endrin is the probable effect concentration (PEC) of 207 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

354529

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

46197

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Endrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

126417

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 7 samples exceeded the water quality standard for Endrin. Data were collected for 6 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723BARWDR, 723PEACHD, 723RICEDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

5534

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 1000 ug/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

5615

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

126439

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 10 samples exceeded the water quality standard for Endrin. Data were collected for 6 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 7 station(s) with the station code(s): 723NRGNDN, 723NRFGDN, 723RI3DRN, 723SCNTDR, 723CNTDRN, 723BARWDR, 723OLANDR.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

127191

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

319309

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156119, Endrin	Region 7
Imperial Valley Drains

LOE ID:

320998

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156173	Region 7
Imperial Valley Drains

Pollutant:	Endrin Ketone
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156173, Endrin Ketone	Region 7
Imperial Valley Drains

LOE ID:

320881

Pollutant:

Endrin Ketone

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171968	Region 7
Imperial Valley Drains

Pollutant:	Ethalfluralin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. 0 of the 20 samples exceed the OBJECTIVE/GUIDELINE/CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 0 of 20 samples exceeded the OBJECTIVE/GUIDELINE/CRITERIA and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 171968, Ethalfluralin	Region 7
Imperial Valley Drains

LOE ID:

354568

Pollutant:

Ethalfluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Ethalfluralin is the USEPA Aquatic Life Benchmark of 0.4 ug/L for a fish (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171968, Ethalfluralin	Region 7
Imperial Valley Drains

LOE ID:

354571

Pollutant:

Ethalfluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Ethalfluralin.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Ethalfluralin is the USEPA Aquatic Life Benchmark of 0.4 ug/L for a fish (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171968, Ethalfluralin	Region 7
Imperial Valley Drains

LOE ID:

354573

Pollutant:

Ethalfluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Ethalfluralin.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Ethalfluralin is the USEPA Aquatic Life Benchmark of 0.4 ug/L for a fish (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171968, Ethalfluralin	Region 7
Imperial Valley Drains

LOE ID:

354560

Pollutant:

Ethalfluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Ethalfluralin is the USEPA Aquatic Life Benchmark of 0.4 ug/L for a fish (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171968, Ethalfluralin	Region 7
Imperial Valley Drains

LOE ID:

354566

Pollutant:

Ethalfluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Ethalfluralin is the USEPA Aquatic Life Benchmark of 0.4 ug/L for a fish (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156153	Region 7
Imperial Valley Drains

Pollutant:	Ethion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355734

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355751

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

351783

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

5541

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 2000 ug/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

320916

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355783

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355791

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MAGDRN (Magnolia Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355787

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355788

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355781

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

354589

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355742

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355765

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS02 (Salton Sea Drain S2 (Niland 4)).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355773

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRFGDN (New River at Fig Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

354587

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355798

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDRN (Verde Drain RWB7).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355767

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355763

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ROSDRN (Rose Drain RWB7).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355764

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-09 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355774

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ARNDRN (N Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355754

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355778

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723HLVLDR (Holtville Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355753

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCNTDR (South Central Drain RWB7).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355752

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355760

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355780

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PEACHD (Peach Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355782

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355772

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355761

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

354581

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355777

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355771

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355730

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NETDRN (Nettle Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355786

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355755

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723RICEDR (Rice Drain at Headgate 101).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355756

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355736

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355750

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355733

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723RI3DRN (Rice 3 Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355796

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355759

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355766

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ARCDRN (C Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355775

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ARIDRN (I Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355779

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355731

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355793

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BDRAIN (B Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355762

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRDRN (Spruce Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355789

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723TI2DRN (Timothy 2 Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355739

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355743

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MUNDRN (Munyon Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355732

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156153, Ethion	Region 7
Imperial Valley Drains

LOE ID:

355749

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ethion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethion is the USEPA Aquatic Life Benchmark of 0.028 ug/L for invertebrates (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.


DECISION ID	156159	Region 7
Imperial Valley Drains

Pollutant:	Ethoprop
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

128733

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

320893

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

354600

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

354590

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

354610

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

354612

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

354606

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

354603

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

354609

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

354615

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156159, Ethoprop	Region 7
Imperial Valley Drains

LOE ID:

354611

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156174	Region 7
Imperial Valley Drains

Pollutant:	Famphur
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156174, Famphur	Region 7
Imperial Valley Drains

LOE ID:

320894

Pollutant:

Famphur

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171971	Region 7
Imperial Valley Drains

Pollutant:	Fenamiphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 171971, Fenamiphos	Region 7
Imperial Valley Drains

LOE ID:

354620

Pollutant:

Fenamiphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fenamiphos is the USEPA Aquatic Life Benchmark of 0.12 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171971, Fenamiphos	Region 7
Imperial Valley Drains

LOE ID:

354623

Pollutant:

Fenamiphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fenamiphos is the USEPA Aquatic Life Benchmark of 0.12 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171971, Fenamiphos	Region 7
Imperial Valley Drains

LOE ID:

354617

Pollutant:

Fenamiphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fenamiphos is the USEPA Aquatic Life Benchmark of 0.12 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171971, Fenamiphos	Region 7
Imperial Valley Drains

LOE ID:

354621

Pollutant:

Fenamiphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fenamiphos is the USEPA Aquatic Life Benchmark of 0.12 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171971, Fenamiphos	Region 7
Imperial Valley Drains

LOE ID:

354619

Pollutant:

Fenamiphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fenamiphos is the USEPA Aquatic Life Benchmark of 0.12 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156166	Region 7
Imperial Valley Drains

Pollutant:	Fenchlorphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156166, Fenchlorphos	Region 7
Imperial Valley Drains

LOE ID:

320721

Pollutant:

Fenchlorphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156182	Region 7
Imperial Valley Drains

Pollutant:	Fenitrothion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156182, Fenitrothion	Region 7
Imperial Valley Drains

LOE ID:

128603

Pollutant:

Fenitrothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Fenitrothion is the USEPA Aquatic Life Benchmark of 0.087 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156182, Fenitrothion	Region 7
Imperial Valley Drains

LOE ID:

320917

Pollutant:

Fenitrothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156182, Fenitrothion	Region 7
Imperial Valley Drains

LOE ID:

354635

Pollutant:

Fenitrothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fenitrothion is the USEPA Aquatic Life Benchmark of 0.087 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156182, Fenitrothion	Region 7
Imperial Valley Drains

LOE ID:

354628

Pollutant:

Fenitrothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fenitrothion is the USEPA Aquatic Life Benchmark of 0.087 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156182, Fenitrothion	Region 7
Imperial Valley Drains

LOE ID:

354634

Pollutant:

Fenitrothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fenitrothion is the USEPA Aquatic Life Benchmark of 0.087 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	170655	Region 7
Imperial Valley Drains

Pollutant:	Fenpropathrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 and 3.6 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

354638

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355799

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355822

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

353747

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fenpropathrin is the median lethal concentration (LC50) of 1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1 ug/g is the geometric mean of LC50 values for fenpropathrin from Ding et al., ( 2011).

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MTSIGD (Mount Signal Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355847

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355843

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355803

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

351812

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

125785

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 26 samples exceeded the evaluation guideline for Fenpropathrin .

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355852

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355845

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BDRAIN (B Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355849

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

353744

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

354657

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2016-03-22 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355815

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355832

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355825

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355807

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355818

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355829

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355820

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355836

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

354651

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

353746

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WRMWDD (Wormwood Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355805

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355809

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355835

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355839

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355840

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355838

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

354650

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

354652

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

354649

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2016-03-22 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355826

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355814

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355806

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 170655, Fenpropathrin	Region 7
Imperial Valley Drains

LOE ID:

355834

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.0015 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156183	Region 7
Imperial Valley Drains

Pollutant:	Fensulfothion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156183, Fensulfothion	Region 7
Imperial Valley Drains

LOE ID:

320918

Pollutant:

Fensulfothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156184	Region 7
Imperial Valley Drains

Pollutant:	Fenthion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). LOE Removal(s): 29872; LOE Replacement(s): 320919

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156184, Fenthion	Region 7
Imperial Valley Drains

LOE ID:

127939

Pollutant:

Fenthion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenthion. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Fenthion is the USEPA Aquatic Life Benchmark of 0.013 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-07 to 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156184, Fenthion	Region 7
Imperial Valley Drains

LOE ID:

320919

Pollutant:

Fenthion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156121	Region 7
Imperial Valley Drains

Pollutant:	Fluoranthene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156121, Fluoranthene	Region 7
Imperial Valley Drains

LOE ID:

353749

Pollutant:

Fluoranthene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156121, Fluoranthene	Region 7
Imperial Valley Drains

LOE ID:

333618

Pollutant:

Fluoranthene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-08 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156121, Fluoranthene	Region 7
Imperial Valley Drains

LOE ID:

320999

Pollutant:

Fluoranthene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156121, Fluoranthene	Region 7
Imperial Valley Drains

LOE ID:

353752

Pollutant:

Fluoranthene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fluoranthene is the probable effect concentration (PEC) of 2230 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	156122	Region 7
Imperial Valley Drains

Pollutant:	Fluorene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156122, Fluorene	Region 7
Imperial Valley Drains

LOE ID:

353759

Pollutant:

Fluorene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156122, Fluorene	Region 7
Imperial Valley Drains

LOE ID:

353760

Pollutant:

Fluorene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for fluorene is the probable effect concentration (PEC) for Fluorene is 536 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156122, Fluorene	Region 7
Imperial Valley Drains

LOE ID:

321009

Pollutant:

Fluorene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156124	Region 7
Imperial Valley Drains

Pollutant:	Heptachlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156124, Heptachlor	Region 7
Imperial Valley Drains

LOE ID:

128077

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Heptachlor.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156124, Heptachlor	Region 7
Imperial Valley Drains

LOE ID:

5625

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156124, Heptachlor	Region 7
Imperial Valley Drains

LOE ID:

126483

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 8 samples exceeded the water quality standard for Heptachlor. Data were collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Heptachlor concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723BARWDR, 723PEACHD, 723RICEDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156124, Heptachlor	Region 7
Imperial Valley Drains

LOE ID:

126231

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 11 samples exceeded the water quality standard for Heptachlor. Data were collected for 7 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 7 station(s) with the station code(s): 723BARWDR, 723NRFGDN, 723SCNTDR, 723NRGNDN, 723RI3DRN, 723CNTDRN, 723OLANDR.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156124, Heptachlor	Region 7
Imperial Valley Drains

LOE ID:

354697

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156124, Heptachlor	Region 7
Imperial Valley Drains

LOE ID:

127489

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156124, Heptachlor	Region 7
Imperial Valley Drains

LOE ID:

319322

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Heptachlor, or Heptachlor Epoxide for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156124, Heptachlor	Region 7
Imperial Valley Drains

LOE ID:

320048

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156124, Heptachlor	Region 7
Imperial Valley Drains

LOE ID:

46200

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Heptachlor. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156125	Region 7
Imperial Valley Drains

Pollutant:	Heptachlor epoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

126611

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 15 samples exceeded the water quality standard for Heptachlor Epoxide. Data were collected for 11 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 1 composite(s) of Mosquitofish each composed of 15 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 60 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Mosquitofish each composed of 7 fish per composite, 1 composite(s) of Mosquitofish each composed of 37 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Heptachlor Epoxide concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 8 station(s) with the station code(s): 723PEACHD, 723NRFGDN, 723BARWDR, 723CNTDRN, 723OLANDR, 723NRGNDN, 723SCNTDR, 723RI3DRN.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

126152

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 8 samples exceeded the water quality standard for Heptachlor Epoxide. Data were collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723PEACHD, 723RICEDR, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

126610

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Waterboard staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: Zero of Zero samples exceeded the water quality standard for Heptachlor Epoxide. Although data was collected for 11 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Mosquitofish each composed of 60 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 37 fish per composite, 1 composite(s) of Mosquitofish each composed of 15 fish per composite, 1 composite(s) of Mosquitofish each composed of 7 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite), all 15 sample(s) had to be thrown out due to quantitation issues.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for heptachlor epoxide in fish tissue is 0.93 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; OEHHA, 1999)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Public Health Goal for Heptachlor and Heptachlor Epoxide in Drinking Water

Spatial Representation:

Data was collected from 8 station(s) with the station code(s): 723PEACHD, 723NRFGDN, 723BARWDR, 723CNTDRN, 723OLANDR, 723NRGNDN, 723SCNTDR, 723RI3DRN.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

126497

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Waterboard staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows: Zero of Zero samples exceeded the water quality standard for Heptachlor Epoxide. Although data was collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite), all 8 sample(s) had to be thrown out due to quantitation issues.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Public Health Goal for Heptachlor and Heptachlor Epoxide in Drinking Water

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723PEACHD, 723RICEDR, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

46213

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor epoxide. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Eleven samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Public Health Goal for Heptachlor and Heptachlor Epoxide in Drinking Water

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

46214

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Heptachlor epoxide. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

354709

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor Epoxide. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The heptachlor epoxide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

319323

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Heptachlor, or Heptachlor Epoxide for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

320049

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

126893

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Heptachlor Epoxide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

127802

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Heptachlor Epoxide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

5634

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156125, Heptachlor epoxide	Region 7
Imperial Valley Drains

LOE ID:

5542

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Twenty-one fish fillet samples and nineteen whole fish samples were taken at 14 locations in Imperial Valley drains. Seventeen fish fillet and 14 whole fish sample results could not be used in this assessment because the sample results were non-detect and the detection limit was above the criteria concentrations. The 4 fish fillet samples and 5 whole fish samples that were acceptable were generally collected from 12/1999 through 11/2000 at five locations. Of these total samples, none OEHHA Screening Value (TSMP, 2007).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 4 ug/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.


DECISION ID	156126	Region 7
Imperial Valley Drains

Pollutant:	Hexachlorobenzene/ HCB
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156126, Hexachlorobenzene/ HCB	Region 7
Imperial Valley Drains

LOE ID:

319617

Pollutant:

Hexachlorobenzene/ HCB

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of alpha-HCH, beta-HCH, Hexachlorobenzene, or Methoxychlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156126, Hexachlorobenzene/ HCB	Region 7
Imperial Valley Drains

LOE ID:

5543

Pollutant:

Hexachlorobenzene/ HCB

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 20 ug/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156126, Hexachlorobenzene/ HCB	Region 7
Imperial Valley Drains

LOE ID:

46215

Pollutant:

Hexachlorobenzene/ HCB

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Hexachlorobenzene. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for hexachlorobenzene in fish tissue is 2.8 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156126, Hexachlorobenzene/ HCB	Region 7
Imperial Valley Drains

LOE ID:

126355

Pollutant:

Hexachlorobenzene/ HCB

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 8 samples exceeded the water quality standard for Hexachlorobenzene. Data were collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723RICEDR, 723PEACHD, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156126, Hexachlorobenzene/ HCB	Region 7
Imperial Valley Drains

LOE ID:

126377

Pollutant:

Hexachlorobenzene/ HCB

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 11 samples exceeded the water quality standard for Hexachlorobenzene. Data were collected for 7 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Data was collected from 7 station(s) with the station code(s): 723BARWDR, 723CNTDRN, 723NRFGDN, 723NRGNDN, 723RI3DRN, 723SCNTDR, 723OLANDR.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	156206	Region 7
Imperial Valley Drains

Pollutant:	Hydroxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156206, Hydroxide	Region 7
Imperial Valley Drains

LOE ID:

319275

Pollutant:

Hydroxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Three water quality samples were collected and analyzed in October of 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for Hydroxide, or Pheophytin a for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Three water samples were collected. Water samples were collected from all three sampling locations and analyzed in May of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156128	Region 7
Imperial Valley Drains

Pollutant:	Indeno[1,2,3-cd]pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156128, Indeno[1,2,3-cd]pyrene	Region 7
Imperial Valley Drains

LOE ID:

319401

Pollutant:

Indeno[1,2,3-cd]pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Acenaphthene, pp-DCBP, or Indeno(1,2,3,c,d)Pyrene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	170781	Region 7
Imperial Valley Drains

Pollutant:	Jasmolin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 170781, Jasmolin	Region 7
Imperial Valley Drains

LOE ID:

355894

Pollutant:

Jasmolin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for jasmolin is the USEPA Aquatic Life Benchmark of 0.04 ug/L for freshwater invertebrates (chronic) and is the sum of jasmolin-1 and jasmolin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	156129	Region 7
Imperial Valley Drains

Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

353776

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-08 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

353766

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRFGDN (New River at Fig Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

354785

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved lead criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-10-16 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

321010

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

319383

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

335461

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

333650

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-09 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

353762

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

353775

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for lead is the probable effect concentration (PEC) of 128 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-10 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

354782

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156129, Lead	Region 7
Imperial Valley Drains

LOE ID:

129064

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 31 monitoring site(s) (723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723CENTD2, 723CNTDRN, 723CTD3MA, 723HLVLDR, 723MAGDRN, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OASISD, 723OLANDR, 723OSAGED, 723PAMPAD, 723PEACHD, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCENTD, 723SCNTDR, 723SPRDRN, 723SSDS02, 723SSDS03, 723SSPDRN, 723TI2DRN, 723UADGUN, 723VERDED, 723VERDRN)

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	156167	Region 7
Imperial Valley Drains

Pollutant:	Leptophos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156167, Leptophos	Region 7
Imperial Valley Drains

LOE ID:

320722

Pollutant:

Leptophos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156130	Region 7
Imperial Valley Drains

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

46198

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for HCH, gamma. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Composites collected at the same time on the same day for the same species were averaged in accordance with the listing policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for lindane in fish tissue is 4.6 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

128307

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The gamma-BHC (Lindane) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

129081

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The gamma-BHC (Lindane) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

6742

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

National Academy of Science (NAS) tissue guideline of 100 ug/kg for the protection of aquatic life uses (NAS, 1973).

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

5544

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 30 ug/kg to protect human health when consuming fish (OEHHA, 1999).

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

353761

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for lindane is the probable effect concentration (PEC) for Lindane is 4.99 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

321011

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

46199

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

National Academy of Science guidelines (NAS 1972) establish a maximum Lindane concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

126223

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 8 samples exceeded the water quality standard for HCH, gamma-. Data were collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723PEACHD, 723RICEDR, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

126183

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 16 samples exceeded the water quality standard for HCH, gamma-. Data were collected for 12 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 1 composite(s) of Mosquitofish each composed of 15 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 60 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Mosquitofish each composed of 7 fish per composite, 1 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 37 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency

Spatial Representation:

Data was collected from 8 station(s) with the station code(s): 723OLANDR, 723PEACHD, 723NRGNDN, 723SCNTDR, 723CNTDRN, 723NRFGDN, 723BARWDR, 723RI3DRN.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

126354

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows 0 of the 8 samples exceeded the water quality standard for HCH, gamma-. Data were collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723PEACHD, 723RICEDR, 723BARWDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

126184

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.

Spatial Representation:

Data was collected from 8 station(s) with the station code(s): 723OLANDR, 723PEACHD, 723NRGNDN, 723SCNTDR, 723CNTDRN, 723NRFGDN, 723BARWDR, 723RI3DRN.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156130, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 7
Imperial Valley Drains

LOE ID:

354681

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The gamma-BHC (Lindane, gamma-HCH) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L. (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7


DECISION ID	156131	Region 7
Imperial Valley Drains

Pollutant:	Malathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). LOE Removal(s): 29872 ; LOE Replacement(s): 320931

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354800

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354820

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354801

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 2 of the 6 samples exceeded the water quality threshold for Malathion. Although a total of 8 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site (723IPVD69).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354788

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354796

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354789

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 1 of the 5 samples exceeded the water quality threshold for Malathion. Although a total of 7 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site (723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354823

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 5 samples exceeded the water quality threshold for Malathion. Although a total of 8 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site (723IPHV10).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354787

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

320931

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

128461

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 11 samples were collected, 11 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

Data was collected from 49 station(s) (Station Code(s) 723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723BDRAIN, 723CENTD2, 723CENTD3, 723CNTDRN, 723CTD3MA, 723EDRAIN, 723ELML6D, 723HLVLDR, 723KDRAIN, 723MAGDRN, 723MARIGD, 723MCALD1, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OASISD, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PEACHD, 723PMLEOD, 723QLATDR, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCENTD, 723SCNTDR, 723SPRDRN, 723SPRUCD, 723SSDS02, 723SSDS03, 723SSPDRN, 723THIS5D, 723TI2DRN, 723TRI12D, 723UADCMC, 723UADGUN, 723UADSPC, 723VAIL7D, 723VAL2AD, 723VERDED, 723VERDRN, 723WILDCD).

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-07 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354803

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354802

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354786

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site (723IPMV61).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354808

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

354818

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 156131, Malathion	Region 7
Imperial Valley Drains

LOE ID:

335495

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The UC Davis Criteria for Malathion for the protection of aquatic organisms is a 4 day average of 0.028 ug/L.

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026


DECISION ID	156132	Region 7
Imperial Valley Drains

Pollutant:	Manganese
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156132, Manganese	Region 7
Imperial Valley Drains

LOE ID:

319385

Pollutant:

Manganese

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Aluminum, Manganese, or Silver for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	172118	Region 7
Imperial Valley Drains

Pollutant:	Mercury
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	"This pollutant is being considered for placement on the section 303(d) list under sections 3.1, 3.5 and 3.6 of the Listing Policy. Under sections 3.1 and 3.5 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. Thirteen lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. LOE 46228 was re-assessed using the new objective and was not included in the final use rating. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. LOE 12737 for COMM water data was retired due to undesignated COMM. LOE 5108 is replaced with LOE 321021 due to a multipollutant LOE being split into LOEs for individual pollutants. The following LOEs were replaced because of reassessment of previous data due to adoption of the statewide mercury objectives: 1) LOE 5565 is replaced with LOEs 357755 and 357759 2) LOE 46228 is replaced with LOEs 133043 and 133339 This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of three TL4 fish tissue samples exceeded the Statewide Sport Fish Water Quality Objective for the protection of the Commercial and Sport Fishing (CDFW). Zero of four TL4 fish tissue samples exceeded the Statewide Sport Fish Water Quality Objective for the protection of Wildlife Habitat (200-500 mm). Zero of one samples exceeded the Statewide Prey Fish Water Quality Objective for the protection of Wildlife Habitat (50-150 mm) for the Wildlife Habitat beneficial use assessed. None of 17 sediment sample exceeded the sediment quality guideline. None of three dissolved and one total water samples exceeded the criteria. These do not exceed the allowable frequency of the Listing Policy in Table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met."

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133336

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 3 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 2 fish were aggregated into 1 annual averages, which consisted of 1 fish species (1 composite(s) of Common Carp each composed of 2 fish per composite).

Data Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The Statewide Sport Fish Water Quality Objective for the protection of Wildlife Habitat comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. If trophic level 3 fish are used in the assessment then the Prey Fish Water Quality Objective must also be used to determine that the Sport Fish Objective is being met. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027.

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2004-11-02 and 2004-11-02

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

132970

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 4 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 7 fish were aggregated into 1 annual averages, which consisted of 2 fish species (1 composite(s) of Channel Catfish each composed of 3 fish per composite, 1 composite(s) of Channel Catfish each composed of 4 fish per composite). This LOE does not contain data from fish whos average length was outside of the legal size limits as described by the California Department of Fish and Wildlife Fishing Regulations.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): 723NROTWM.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-09 and 2011-11-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133249

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 4 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 7 fish were aggregated into 1 annual averages, which consisted of 2 fish species (1 composite(s) of Channel Catfish each composed of 4 fish per composite, 1 composite(s) of Channel Catfish each composed of 3 fish per composite). This LOE does not contain data from fish whos average length was outside of the legal size limits as described by the California Department of Fish and Wildlife Fishing Regulations.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The Statewide Sport Fish Water Quality Objective for the protection of the Commercial and Sport Fishing beneficial comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027.

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): 723NROTWM.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-09 and 2011-11-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133043

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 4 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 17 fish were aggregated into 2 annual averages, which consisted of 2 fish species (5 composite(s) of Channel Catfish each composed of 3 fish per composite, 1 composite(s) of Channel Catfish each composed of 2 fish per composite). This LOE does not contain data from fish whos average length was outside of the legal size limits as described by the California Department of Fish and Wildlife Fishing Regulations.

Data Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 2 station(s) with the station code(s): 723GRSDRN, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2004-11-02 and 2004-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

132890

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 4 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 7 fish were aggregated into 1 annual averages, which consisted of 2 fish species (1 composite(s) of Channel Catfish each composed of 4 fish per composite, 1 composite(s) of Channel Catfish each composed of 3 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): 723NROTWM.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-09 and 2011-11-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133054

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 2 station(s) with the station code(s): 723CNTDRN, 723GRSDRN.

Temporal Representation:

Data for this line of evidence were collected between 2004-11-02 and 2004-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133277

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 3 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 19 fish were aggregated into 6 annual averages, which consisted of 4 fish species (1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Common Carp each composed of 2 fish per composite, 2 composite(s) of Common Carp each composed of 3 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite). This LOE does not contain data from fish whos average length was outside of the legal size limits as described by the California Department of Fish and Wildlife Fishing Regulations.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 5 station(s) with the station code(s): 723OLANDR, 723NROTWM, 723NRFGDN, 723RI3DRN, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2012-04-04 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133145

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 3 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 19 fish were aggregated into 6 annual averages, which consisted of 4 fish species (1 composite(s) of Common Carp each composed of 2 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 2 composite(s) of Common Carp each composed of 3 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 5 station(s) with the station code(s): 723NROTWM, 723OLANDR, 723NRFGDN, 723CNTDRN, 723RI3DRN.

Temporal Representation:

Data for this line of evidence were collected between 2012-04-04 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133004

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2004-11-02 and 2004-11-02

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

132912

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2004-11-02 and 2004-11-02

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133140

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 3 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 19 fish were aggregated into 6 annual averages, which consisted of 4 fish species (2 composite(s) of Common Carp each composed of 3 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Common Carp each composed of 2 fish per composite). This LOE does not contain data from fish whos average length was outside of the legal size limits as described by the California Department of Fish and Wildlife Fishing Regulations.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 5 station(s) with the station code(s): 723NROTWM, 723OLANDR, 723NRFGDN, 723RI3DRN, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2012-04-04 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

357759

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Toxic Substances Monitoring Program data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 4 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 2 fish were aggregated into 1 annual averages, which consisted of 1 fish species (1 composite(s) of Channel Catfish each composed of 2 fish per composite). This LOE does not contain data from fish whos average length was outside of the legal size limits as described by the California Department of Fish and Wildlife Fishing Regulations.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): Pumice Drain.

Temporal Representation:

Data for this line of evidence were collected between 1990-11-20 and 1990-11-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

357755

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): Pumice Drain.

Temporal Representation:

Data for this line of evidence were collected between 1990-11-20 and 1990-11-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Toxic Substances Monitoring Program 1991 Data Report. 93-1WQ. State Water Resources Control Board (SWRCB), Division of Water Quality. Sacramento, CA.

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

354835

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

321021

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

354829

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

354831

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

354834

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

125454

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 12 samples exceeded the evaluation guideline for Mercury .

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Mercury from MacDonald et al., 2000a which states that the probable effect concentration for Mercury is 1.06 mg/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 12 (Station Codes: 723CENTD2, 723CTD3MA, 723OASISD, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PMLEOD, 723SCENTD, 723TRI12D, 723UADGUN, 723VERDED).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133339

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 4 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 17 fish were aggregated into 2 annual averages, which consisted of 2 fish species (1 composite(s) of Channel Catfish each composed of 2 fish per composite, 5 composite(s) of Channel Catfish each composed of 3 fish per composite).

Data Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 2 station(s) with the station code(s): 723GRSDRN, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2004-11-02 and 2004-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

132967

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 4 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 7 fish were aggregated into 1 annual averages, which consisted of 2 fish species (1 composite(s) of Channel Catfish each composed of 4 fish per composite, 1 composite(s) of Channel Catfish each composed of 3 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): 723NROTWM.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-09 and 2011-11-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133341

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality standard for Mercury. All fish collected within the same calendar year with a reported length of 50-150 mm were averaged into a single sample, independent of species or trophic level, for comparison with the objective. This LOE consists of a total of 7 fish, which were aggregated into 1 annual averages, consisting of 1 fish species (1 composite(s) of Mosquitofish each composed of 7 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The Statewide Prey Fish Water Quality Objective for the protection of Wildlife Habitat comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.05 mg/Kg wet weight whole fish samples of any fish species between 50 to 150 mm in total length collected between February 1 and July 31. (SWRCB Resolution No. 2017-0027)

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): 723PEACHD.

Temporal Representation:

Data for this line of evidence were collected between 2012-10-15 and 2012-10-15

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133109

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 2 station(s) with the station code(s): 723GRSDRN, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2004-11-02 and 2004-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133069

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the water quality standard for Mercury. This LOE contains data only for trophic level 3 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 19 fish were aggregated into 6 annual averages, which consisted of 4 fish species (1 composite(s) of Common Carp each composed of 1 fish per composite, 2 composite(s) of Common Carp each composed of 3 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Common Carp each composed of 2 fish per composite).

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 5 station(s) with the station code(s): 723OLANDR, 723NRFGDN, 723CNTDRN, 723NROTWM, 723RI3DRN.

Temporal Representation:

Data for this line of evidence were collected between 2012-04-04 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 172118, Mercury	Region 7
Imperial Valley Drains

LOE ID:

133167

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Spatial Representation:

Data was collected from 1 station(s) with the station code(s): 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2004-11-02 and 2004-11-02

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156168	Region 7
Imperial Valley Drains

Pollutant:	Merphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156168, Merphos	Region 7
Imperial Valley Drains

LOE ID:

320723

Pollutant:

Merphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156156	Region 7
Imperial Valley Drains

Pollutant:	Methidathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). LOE Removal(s): 29872; LOE Replacement(s): 320932 The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

354859

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Methidathion.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

354849

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Methidathion.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

354852

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

354837

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

354843

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

354855

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

354858

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

354844

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

320932

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

128040

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 45 samples exceeded the water quality standard for Methidathion.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

335538

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

354860

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156156, Methidathion	Region 7
Imperial Valley Drains

LOE ID:

354847

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	171964	Region 7
Imperial Valley Drains

Pollutant:	Methiocarb
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171964, Methiocarb	Region 7
Imperial Valley Drains

LOE ID:

354863

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methiocarb is the USEPA Aquatic Life Benchmark of 2.75 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171964, Methiocarb	Region 7
Imperial Valley Drains

LOE ID:

354864

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methiocarb is the USEPA Aquatic Life Benchmark of 2.75 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171964, Methiocarb	Region 7
Imperial Valley Drains

LOE ID:

354862

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methiocarb is the USEPA Aquatic Life Benchmark of 2.75 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171964, Methiocarb	Region 7
Imperial Valley Drains

LOE ID:

354869

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methiocarb is the USEPA Aquatic Life Benchmark of 2.75 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171964, Methiocarb	Region 7
Imperial Valley Drains

LOE ID:

354870

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methiocarb is the USEPA Aquatic Life Benchmark of 2.75 ug/L for an invertebrate (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	171965	Region 7
Imperial Valley Drains

Pollutant:	Methomyl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171965, Methomyl	Region 7
Imperial Valley Drains

LOE ID:

354880

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Methomyl.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methomyl is the USEPA Aquatic Life Benchmark of 0.6 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171965, Methomyl	Region 7
Imperial Valley Drains

LOE ID:

354882

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methomyl is the USEPA Aquatic Life Benchmark of 0.6 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171965, Methomyl	Region 7
Imperial Valley Drains

LOE ID:

354872

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methomyl is the USEPA Aquatic Life Benchmark of 0.6 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171965, Methomyl	Region 7
Imperial Valley Drains

LOE ID:

354878

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methomyl is the USEPA Aquatic Life Benchmark of 0.6 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171965, Methomyl	Region 7
Imperial Valley Drains

LOE ID:

354877

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methomyl is the USEPA Aquatic Life Benchmark of 0.6 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156133	Region 7
Imperial Valley Drains

Pollutant:	Methoxychlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). LOE Removal(s): 30073; LOE Replacement(s): 319618 The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 156133, Methoxychlor	Region 7
Imperial Valley Drains

LOE ID:

354887

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA national ambient water quality criterion for freshwater aquatic life Criterion Continuous Concentration (CCC) expressed as a 4-day average for methoxychlor is 0.03 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

Line of Evidence (LOE) for Decision ID 156133, Methoxychlor	Region 7
Imperial Valley Drains

LOE ID:

127658

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

According to the National Recommended Water Quality Criteria, the maximum (instantaneous) criteria to protect aquatic life from levels of mirex in water is 0.03 ug/l.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156133, Methoxychlor	Region 7
Imperial Valley Drains

LOE ID:

128692

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

According to the National Recommended Water Quality Criteria, the maximum (instantaneous) criteria to protect aquatic life from levels of mirex in water is 0.03 ug/l.

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156133, Methoxychlor	Region 7
Imperial Valley Drains

LOE ID:

319618

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of alpha-HCH, beta-HCH, Hexachlorobenzene, or Methoxychlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171975	Region 7
Imperial Valley Drains

Pollutant:	Methoxyfenozide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 171975, Methoxyfenozide	Region 7
Imperial Valley Drains

LOE ID:

354904

Pollutant:

Methoxyfenozide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methoxyfenozide is the USEPA Aquatic Life Benchmark of 3.1 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2015-10-13 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171975, Methoxyfenozide	Region 7
Imperial Valley Drains

LOE ID:

354896

Pollutant:

Methoxyfenozide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methoxyfenozide is the USEPA Aquatic Life Benchmark of 3.1 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2015-10-13 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171975, Methoxyfenozide	Region 7
Imperial Valley Drains

LOE ID:

354897

Pollutant:

Methoxyfenozide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methoxyfenozide is the USEPA Aquatic Life Benchmark of 3.1 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2015-10-13 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171975, Methoxyfenozide	Region 7
Imperial Valley Drains

LOE ID:

354900

Pollutant:

Methoxyfenozide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for methoxyfenozide is the USEPA Aquatic Life Benchmark of 3.1 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2015-10-13 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156134	Region 7
Imperial Valley Drains

Pollutant:	Methyl Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). LOE Removal(s): 29872, 30054; LOE Replacement(s): 320933, 319290

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

355054

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental phyusiological responses in human, plant, animal, or indigenous aquatic life. (Colorado River Basin)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for methyl parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

355048

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for methyl parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

128940

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Methyl. Although a total of 11 samples were collected, 11 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The California Department of Fish and Game instantaneous criteria for Methyl Parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-07 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

319290

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Ethyl Parathion, or Methyl Parathion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

320933

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

355057

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Methyl. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for methyl parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

355046

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for methyl parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

355070

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Methyl. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for methyl parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

355064

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Methyl. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for methyl parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

355050

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for methyl parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

355069

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for methyl parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 156134, Methyl Parathion	Region 7
Imperial Valley Drains

LOE ID:

355062

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for methyl parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691


DECISION ID	156169	Region 7
Imperial Valley Drains

Pollutant:	Mevinphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156169, Mevinphos	Region 7
Imperial Valley Drains

LOE ID:

320736

Pollutant:

Mevinphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156135	Region 7
Imperial Valley Drains

Pollutant:	Mirex
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156135, Mirex	Region 7
Imperial Valley Drains

LOE ID:

126274

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Waterboard staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: Zero of Zero samples exceeded the water quality standard for Mirex. Although data was collected for 7 fish species (1 composite(s) of Mosquitofish each composed of 25 fish per composite, 2 composite(s) of Common Carp each composed of 5 fish per composite, 1 composite(s) of Common Carp each composed of 3 fish per composite, 4 composite(s) of Tilapia spp. each composed of 5 fish per composite, 1 composite(s) of Tilapia spp. each composed of 6 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Grass Carp each composed of 4 fish per composite), all 11 sample(s) had to be thrown out due to quantitation issues.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for mirex in fish tissue is 0.28 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets. (Klasing, S., and R. Brodberg, 2008; OEHHA, 1992)

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Expedited Cancer Potency Values and Proposed Regulatory Levels for Certain Proposition 65 Carcinogens.

Spatial Representation:

Data was collected from 7 station(s) with the station code(s): 723NRFGDN, 723BARWDR, 723NRGNDN, 723OLANDR, 723CNTDRN, 723SCNTDR, 723RI3DRN.

Temporal Representation:

Data for this line of evidence were collected between 2012-05-07 and 2014-12-08

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156135, Mirex	Region 7
Imperial Valley Drains

LOE ID:

320895

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156135, Mirex	Region 7
Imperial Valley Drains

LOE ID:

128349

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Mirex. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The criterion continuous concentraion for Mirex is 0.001 ug/l from the National Recommended Water Quality Criteria.

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 723CNTDRN).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-02-11 to 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156135, Mirex	Region 7
Imperial Valley Drains

LOE ID:

128916

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Mirex. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The criterion continuous concentraion for Mirex is 0.001 ug/l from the National Recommended Water Quality Criteria.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-07 to 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156135, Mirex	Region 7
Imperial Valley Drains

LOE ID:

319454

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Dacthal, Mirex, or Oxadiazon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156135, Mirex	Region 7
Imperial Valley Drains

LOE ID:

46229

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Mirex. Eleven composites (2 - 3 fish per composite) were generated from three species: common carp, Tilapia spp, and channel catfish. Eleven samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The modified OEHHA Fish Contaminant Goal for mirex in fish tissue is 0.28 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Expedited Cancer Potency Values and Proposed Regulatory Levels for Certain Proposition 65 Carcinogens.

Spatial Representation:

Data for this line of evidence for Imperial Valley Drains was collected at 2 monitoring sites [ Central Drain - 723CNTDRN, Greeson Drain - 723GRSDRN]

Temporal Representation:

Data was collected over the time period 11/2/2004-11/4/2004.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

The SWAMP QAPP (2002) was followed.

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156135, Mirex	Region 7
Imperial Valley Drains

LOE ID:

126488

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Fish fillet

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Waterboard staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and the results are as follows: Zero of Zero samples exceeded the water quality standard for Mirex. Although data was collected for 7 fish species (2 composite(s) of Mosquitofish each composed of 48 fish per composite, 1 composite(s) of Mosquitofish each composed of 45 fish per composite, 1 composite(s) of Common Carp each composed of 1 fish per composite, 1 composite(s) of Common Carp each composed of 4 fish per composite, 1 composite(s) of Mosquitofish each composed of 117 fish per composite, 1 composite(s) of Mosquitofish each composed of 72 fish per composite, 1 composite(s) of Mosquitofish each composed of 18 fish per composite), all 8 sample(s) had to be thrown out due to quantitation issues.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene

Guideline Reference:

Expedited Cancer Potency Values and Proposed Regulatory Levels for Certain Proposition 65 Carcinogens.

Spatial Representation:

Data was collected from 4 station(s) with the station code(s): 723PEACHD, 723BARWDR, 723RICEDR, 723CNTDRN.

Temporal Representation:

Data for this line of evidence were collected between 2011-02-07 and 2011-04-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	156175	Region 7
Imperial Valley Drains

Pollutant:	Naled
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156175, Naled	Region 7
Imperial Valley Drains

LOE ID:

320896

Pollutant:

Naled

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156136	Region 7
Imperial Valley Drains

Pollutant:	Naphthalene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156136, Naphthalene	Region 7
Imperial Valley Drains

LOE ID:

354921

Pollutant:

Naphthalene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The USEPA recommended naphthalene criterion for the protection of freshwater aquatic life is 620 ug/l. (EPA 440/5-80-059)

Guideline Reference:

Ambient Water Quality Criteria for Naphthalene

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156136, Naphthalene	Region 7
Imperial Valley Drains

LOE ID:

321022

Pollutant:

Naphthalene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156136, Naphthalene	Region 7
Imperial Valley Drains

LOE ID:

320016

Pollutant:

Naphthalene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Naphthalene, Acenaphthylene, 1-Methylnaphthalene, 2-Methynaphthalene, 2,6-Dimethylnaphthalene, or 2,3,5-Trimethylnaphthalene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156136, Naphthalene	Region 7
Imperial Valley Drains

LOE ID:

353787

Pollutant:

Naphthalene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-14 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156136, Naphthalene	Region 7
Imperial Valley Drains

LOE ID:

353789

Pollutant:

Naphthalene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for naphthalene is the probable effect concentration (PEC) of 561 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	156137	Region 7
Imperial Valley Drains

Pollutant:	Nickel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

353806

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

354924

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

353800

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-10 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

333669

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-09 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

353797

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-08 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

354927

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

353803

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for nickel is the probable effect concentration (PEC) of 48.6 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRFGDN (New River at Fig Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

335613

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

319718

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

127670

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156137, Nickel	Region 7
Imperial Valley Drains

LOE ID:

321023

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171966	Region 7
Imperial Valley Drains

Pollutant:	Oryzalin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. Zero of the 20 samples exceed the guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 20 samples exceed the guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171966, Oryzalin	Region 7
Imperial Valley Drains

LOE ID:

354947

Pollutant:

Oryzalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for oryzalin is the USEPA Aquatic Life Benchmark of 13 ug/L for a vascular plant (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171966, Oryzalin	Region 7
Imperial Valley Drains

LOE ID:

354938

Pollutant:

Oryzalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for oryzalin is the USEPA Aquatic Life Benchmark of 13 ug/L for a vascular plant (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171966, Oryzalin	Region 7
Imperial Valley Drains

LOE ID:

354940

Pollutant:

Oryzalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for oryzalin is the USEPA Aquatic Life Benchmark of 13 ug/L for a vascular plant (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171966, Oryzalin	Region 7
Imperial Valley Drains

LOE ID:

354937

Pollutant:

Oryzalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for oryzalin is the USEPA Aquatic Life Benchmark of 13 ug/L for a vascular plant (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171966, Oryzalin	Region 7
Imperial Valley Drains

LOE ID:

354936

Pollutant:

Oryzalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for oryzalin is the USEPA Aquatic Life Benchmark of 13 ug/L for a vascular plant (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156138	Region 7
Imperial Valley Drains

Pollutant:	Oxadiazon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. 25 lines of evidence are available in the administrative record to assess this pollutant. Zero samples exceed the guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero samples exceeded the guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356027

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356030

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723TI2DRN (Timothy 2 Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

355995

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCNTDR (South Central Drain RWB7).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356029

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356021

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ROSDRN (Rose Drain RWB7).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356035

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MAGDRN (Magnolia Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356016

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723RICEDR (Rice Drain at Headgate 101).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

355991

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723RI3DRN (Rice 3 Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356023

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDRN (Verde Drain RWB7).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356000

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PEACHD (Peach Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356009

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRDRN (Spruce Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356008

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS02 (Salton Sea Drain S2 (Niland 4)).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356007

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-09 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

355999

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356024

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ARIDRN (I Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356015

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ARNDRN (N Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356005

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356014

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRFGDN (New River at Fig Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

355996

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723HLVLDR (Holtville Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356020

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MUNDRN (Munyon Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

356010

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ARCDRN (C Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

355998

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NETDRN (Nettle Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

355992

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB7 TMDL data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Oxadiazon.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for Oxadiazon is the USEPA Aquatic Life Benchmark of 0.88 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

319455

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Dacthal, Mirex, or Oxadiazon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156138, Oxadiazon	Region 7
Imperial Valley Drains

LOE ID:

320908

Pollutant:

Oxadiazon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171960	Region 7
Imperial Valley Drains

Pollutant:	Oxamyl (Vydate)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171960, Oxamyl (Vydate)	Region 7
Imperial Valley Drains

LOE ID:

354964

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for oxamyl is the USEPA Aquatic Life Benchmark of 27 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 73 (Pine Drain btwn HWY 115 and Anderson).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171960, Oxamyl (Vydate)	Region 7
Imperial Valley Drains

LOE ID:

354971

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for oxamyl is the USEPA Aquatic Life Benchmark of 27 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171960, Oxamyl (Vydate)	Region 7
Imperial Valley Drains

LOE ID:

354967

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for oxamyl is the USEPA Aquatic Life Benchmark of 27 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171960, Oxamyl (Vydate)	Region 7
Imperial Valley Drains

LOE ID:

354972

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for oxamyl is the USEPA Aquatic Life Benchmark of 27 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171960, Oxamyl (Vydate)	Region 7
Imperial Valley Drains

LOE ID:

354963

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for oxamyl is the USEPA Aquatic Life Benchmark of 27 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-10-11 and 2011-10-11

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156192	Region 7
Imperial Valley Drains

Pollutant:	Oxychlordane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156192, Oxychlordane	Region 7
Imperial Valley Drains

LOE ID:

320734

Pollutant:

Oxychlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156192, Oxychlordane	Region 7
Imperial Valley Drains

LOE ID:

319456

Pollutant:

Oxychlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Oxychlordane, Perylene, or Tedion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171967	Region 7
Imperial Valley Drains

Pollutant:	Oxyfluorfen
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. 1 of the 20 samples exceed the evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 1 of 20 samples exceeded the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171967, Oxyfluorfen	Region 7
Imperial Valley Drains

LOE ID:

354989

Pollutant:

Oxyfluorfen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of oxyfluorfen does not exceed 0.14 ug/L (Bower, et al. 2017).

Guideline Reference:

Water quality criteria report for Oxyfluorfen. Phase III: application of the pesticide water quality criteria methodology.

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171967, Oxyfluorfen	Region 7
Imperial Valley Drains

LOE ID:

354973

Pollutant:

Oxyfluorfen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of oxyfluorfen does not exceed 0.14 ug/L (Bower, et al. 2017).

Guideline Reference:

Water quality criteria report for Oxyfluorfen. Phase III: application of the pesticide water quality criteria methodology.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171967, Oxyfluorfen	Region 7
Imperial Valley Drains

LOE ID:

354975

Pollutant:

Oxyfluorfen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of oxyfluorfen does not exceed 0.14 ug/L (Bower, et al. 2017).

Guideline Reference:

Water quality criteria report for Oxyfluorfen. Phase III: application of the pesticide water quality criteria methodology.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171967, Oxyfluorfen	Region 7
Imperial Valley Drains

LOE ID:

354976

Pollutant:

Oxyfluorfen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 1 of 5 samples exceeded the water quality threshold for Oxyfluorfen.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of oxyfluorfen does not exceed 0.14 ug/L (Bower, et al. 2017).

Guideline Reference:

Water quality criteria report for Oxyfluorfen. Phase III: application of the pesticide water quality criteria methodology.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171967, Oxyfluorfen	Region 7
Imperial Valley Drains

LOE ID:

354984

Pollutant:

Oxyfluorfen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of oxyfluorfen does not exceed 0.14 ug/L (Bower, et al. 2017).

Guideline Reference:

Water quality criteria report for Oxyfluorfen. Phase III: application of the pesticide water quality criteria methodology.

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691


DECISION ID	159216	Region 7
Imperial Valley Drains

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. 19 lines of evidence are available in the administrative record to assess this pollutant. Five of 109 samples exceed the Water Quality Control Plan, Colorado River Basin, Warm Water Habitat Objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Five of 109 samples exceed the Water Quality Control Plan, Colorado River Basin, Warm Water Habitat Objective. This does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355005

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Colorado River Basin, WARM Water Habitat Objective, Chapter III, states the following: The dissolved oxygen concentration for warm water habitats shall not be reduced below 5.0 mg/l at any time.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

354998

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355031

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRFGDN (New River at Fig Drain).

Temporal Representation:

The samples were collected between the dates of 2018-11-14 and 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355025

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355011

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

The samples were collected between the dates of 2018-11-14 and 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355008

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PEACHD (Peach Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355012

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355006

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355016

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS02 (Salton Sea Drain S2 (Niland 4)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355029

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

354999

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

354991

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355004

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355030

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355017

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355020

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

335722

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 1 of 3 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

127297

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 3 of 76 samples exceeded the water quality standard for Oxygen, Dissolved.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Colorado River Basin, WARM Water Habitat Objective, Chapter III, states the following: The dissolved oxygen concentration for cold water habitats shall not be reduced below 5.0 mg/l at any time.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 51 monitoring site(s) (723ARCDRN, 723ARIDRN, 723ARNDRN, 723BARWDR, 723BDRAIN, 723CENTD2, 723CENTD3, 723CNTDRN, 723CTD3MA, 723EDRAIN, 723ELML6D, 723HLVLDR, 723KDRAIN, 723MAGDRN, 723MALVAD, 723MARIGD, 723MCALD1, 723MUNDRN, 723NETDRN, 723NRFGDN, 723NRGNDN, 723OASISD, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PEACHD, 723PMLEOD, 723QLATDR, 723RI3DRN, 723RICEDR, 723ROSDRN, 723SCENTD, 723SCNTDR, 723SPRDRN, 723SPRUCD, 723SSDS02, 723SSDS03, 723SSPDRN, 723THIS5D, 723TI2DRN, 723TRI12D, 723UADCMC, 723UADGUN, 723UADSPC, 723VAIL7D, 723VAL2AD, 723VERDED, 723VERDRN, 723WILDCD, 728SSDS01)

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

354992

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159216, Oxygen, Dissolved	Region 7
Imperial Valley Drains

LOE ID:

355000

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	169598	Region 7
Imperial Valley Drains

Pollutant:	PAHs (Polycyclic Aromatic Hydrocarbons)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 169598, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 7
Imperial Valley Drains

LOE ID:

333706

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-08 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169598, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 7
Imperial Valley Drains

LOE ID:

353813

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-14 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169598, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 7
Imperial Valley Drains

LOE ID:

353818

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 169598, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 7
Imperial Valley Drains

LOE ID:

353816

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for total PAHs is the probable effect concentration (PEC) of 22800 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	156140	Region 7
Imperial Valley Drains

Pollutant:	Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s).

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156140, Parathion	Region 7
Imperial Valley Drains

LOE ID:

355042

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Ethyl. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The criterion continuous concentraion for Parathion, Ethyl is 0.013 ug/l from the National Recommended Water Quality Criteria.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156140, Parathion	Region 7
Imperial Valley Drains

LOE ID:

128491

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Ethyl. Although a total of 11 samples were collected, 11 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The criterion continuous concentraion for Parathion, Ethyl is 0.013 ug/l from the National Recommended Water Quality Criteria.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-07 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156140, Parathion	Region 7
Imperial Valley Drains

LOE ID:

355044

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Ethyl. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The criterion continuous concentraion for Parathion, Ethyl is 0.013 ug/l from the National Recommended Water Quality Criteria.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156140, Parathion	Region 7
Imperial Valley Drains

LOE ID:

319291

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Ethyl Parathion, or Methyl Parathion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156140, Parathion	Region 7
Imperial Valley Drains

LOE ID:

355037

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Ethyl. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The criterion continuous concentraion for Parathion, Ethyl is 0.013 ug/l from the National Recommended Water Quality Criteria.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156140, Parathion	Region 7
Imperial Valley Drains

LOE ID:

320934

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171969	Region 7
Imperial Valley Drains

Pollutant:	Pendimethalin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. 1 of the 20 samples exceed the OBJECTIVE/GUIDELINE/CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 1 of 20 samples exceeded the OBJECTIVE/GUIDELINE/CRITERIA and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 171969, Pendimethalin	Region 7
Imperial Valley Drains

LOE ID:

355085

Pollutant:

Pendimethalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pendimethalin is the USEPA Aquatic Life Benchmark of 5.2 ug/L for a nonvascular plant (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171969, Pendimethalin	Region 7
Imperial Valley Drains

LOE ID:

355083

Pollutant:

Pendimethalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pendimethalin is the USEPA Aquatic Life Benchmark of 5.2 ug/L for a nonvascular plant (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171969, Pendimethalin	Region 7
Imperial Valley Drains

LOE ID:

355086

Pollutant:

Pendimethalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pendimethalin is the USEPA Aquatic Life Benchmark of 5.2 ug/L for a nonvascular plant (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171969, Pendimethalin	Region 7
Imperial Valley Drains

LOE ID:

355074

Pollutant:

Pendimethalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pendimethalin is the USEPA Aquatic Life Benchmark of 5.2 ug/L for a nonvascular plant (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171969, Pendimethalin	Region 7
Imperial Valley Drains

LOE ID:

355079

Pollutant:

Pendimethalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pendimethalin is the USEPA Aquatic Life Benchmark of 5.2 ug/L for a nonvascular plant (acute).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156193	Region 7
Imperial Valley Drains

Pollutant:	Perylene (Dibenz(de,kl)anthracene)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156193, Perylene (Dibenz(de,kl)anthracene)	Region 7
Imperial Valley Drains

LOE ID:

320735

Pollutant:

Perylene (Dibenz(de,kl)anthracene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156193, Perylene (Dibenz(de,kl)anthracene)	Region 7
Imperial Valley Drains

LOE ID:

319467

Pollutant:

Perylene (Dibenz(de,kl)anthracene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Oxychlordane, Perylene, or Tedion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156141	Region 7
Imperial Valley Drains

Pollutant:	Phenanthrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156141, Phenanthrene	Region 7
Imperial Valley Drains

LOE ID:

353836

Pollutant:

Phenanthrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156141, Phenanthrene	Region 7
Imperial Valley Drains

LOE ID:

353831

Pollutant:

Phenanthrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156141, Phenanthrene	Region 7
Imperial Valley Drains

LOE ID:

353835

Pollutant:

Phenanthrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phenanthrene is the probable effect concentration (PEC) of 1170 ug/kg dry weight (MacDonald et al.).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-14 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156141, Phenanthrene	Region 7
Imperial Valley Drains

LOE ID:

319268

Pollutant:

Phenanthrene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Phenanthrene, or 1-Methylphenanthrene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156141, Phenanthrene	Region 7
Imperial Valley Drains

LOE ID:

321034

Pollutant:

Phenanthrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156205	Region 7
Imperial Valley Drains

Pollutant:	Pheophytin a
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156205, Pheophytin a	Region 7
Imperial Valley Drains

LOE ID:

319276

Pollutant:

Pheophytin a

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Three water quality samples were collected and analyzed in October of 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for Hydroxide, or Pheophytin a for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Three water samples were collected. Water samples were collected from all three sampling locations and analyzed in May of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156160	Region 7
Imperial Valley Drains

Pollutant:	Phorate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s). The number of measured exceedances is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicant pollutants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that this water segment-pollutant combination should not be placed on the CWA section 303(d) List. Refer to the lines of evidence in this fact sheet for the data and information, sample counts and exceedances, quality assurance documentation, beneficial uses, and water quality objectives or numeric evaluation guidelines relied upon for this decision.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156160, Phorate	Region 7
Imperial Valley Drains

LOE ID:

127850

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156160, Phorate	Region 7
Imperial Valley Drains

LOE ID:

320748

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156160, Phorate	Region 7
Imperial Valley Drains

LOE ID:

355173

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156160, Phorate	Region 7
Imperial Valley Drains

LOE ID:

355163

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156160, Phorate	Region 7
Imperial Valley Drains

LOE ID:

355166

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156160, Phorate	Region 7
Imperial Valley Drains

LOE ID:

355169

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156160, Phorate	Region 7
Imperial Valley Drains

LOE ID:

355178

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156185	Region 7
Imperial Valley Drains

Pollutant:	Phosmet
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. 22 lines of evidence are available in the administrative record to assess this pollutant. Zero samples exceed the guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero samples exceeded the guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356147

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MAGDRN (Magnolia Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356119

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PEACHD (Peach Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356121

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS02 (Salton Sea Drain S2 (Niland 4)).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356125

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ARCDRN (C Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356132

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCNTDR (South Central Drain RWB7).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356135

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356133

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MUNDRN (Munyon Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356128

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDRN (Verde Drain RWB7).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356158

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723RICEDR (Rice Drain at Headgate 101).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356139

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723TI2DRN (Timothy 2 Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

320749

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356117

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356144

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-09 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356120

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRFGDN (New River at Fig Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356134

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723HLVLDR (Holtville Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356112

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356137

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ARIDRN (I Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356140

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ARNDRN (N Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356142

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ROSDRN (Rose Drain RWB7).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356109

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRDRN (Spruce Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356113

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NETDRN (Nettle Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-15

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356118

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723RI3DRN (Rice 3 Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-16

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156185, Phosmet	Region 7
Imperial Valley Drains

LOE ID:

356138

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for phosmet is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2012-05-08 and 2012-10-17

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156186	Region 7
Imperial Valley Drains

Pollutant:	Phosphamidon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156186, Phosphamidon	Region 7
Imperial Valley Drains

LOE ID:

320750

Pollutant:

Phosphamidon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171972	Region 7
Imperial Valley Drains

Pollutant:	Prodiamine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 171972, Prodiamine	Region 7
Imperial Valley Drains

LOE ID:

355185

Pollutant:

Prodiamine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for prodiamine is the USEPA Aquatic Life Benchmark of 1.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171972, Prodiamine	Region 7
Imperial Valley Drains

LOE ID:

355192

Pollutant:

Prodiamine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for prodiamine is the USEPA Aquatic Life Benchmark of 1.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171972, Prodiamine	Region 7
Imperial Valley Drains

LOE ID:

355183

Pollutant:

Prodiamine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for prodiamine is the USEPA Aquatic Life Benchmark of 1.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171972, Prodiamine	Region 7
Imperial Valley Drains

LOE ID:

355190

Pollutant:

Prodiamine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for prodiamine is the USEPA Aquatic Life Benchmark of 1.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171972, Prodiamine	Region 7
Imperial Valley Drains

LOE ID:

355187

Pollutant:

Prodiamine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for prodiamine is the USEPA Aquatic Life Benchmark of 1.5 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156143	Region 7
Imperial Valley Drains

Pollutant:	Prometon (Prometone)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156143, Prometon (Prometone)	Region 7
Imperial Valley Drains

LOE ID:

319466

Pollutant:

Prometon (Prometone)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Atroton, Prometon, or Secbumeton for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156157	Region 7
Imperial Valley Drains

Pollutant:	Prometryn
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156157, Prometryn	Region 7
Imperial Valley Drains

LOE ID:

319819

Pollutant:

Prometryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ametryn, Prometryn, Simetryn, or Terbutryn for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156203	Region 7
Imperial Valley Drains

Pollutant:	Propazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156203, Propazine	Region 7
Imperial Valley Drains

LOE ID:

319273

Pollutant:

Propazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Propazine, or Terbuthylazine for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156144	Region 7
Imperial Valley Drains

Pollutant:	Pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156144, Pyrene	Region 7
Imperial Valley Drains

LOE ID:

321035

Pollutant:

Pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed biannually from 5/2002 through 5/2005 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the PEC (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156144, Pyrene	Region 7
Imperial Valley Drains

LOE ID:

353842

Pollutant:

Pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-07 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156144, Pyrene	Region 7
Imperial Valley Drains

LOE ID:

353844

Pollutant:

Pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-14 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156144, Pyrene	Region 7
Imperial Valley Drains

LOE ID:

353840

Pollutant:

Pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

Data for this waterbody were collected over the date range 2017-07-11 to 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156144, Pyrene	Region 7
Imperial Valley Drains

LOE ID:

333721

Pollutant:

Pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pyrene is the probable effect concentration (PEC) of 1520 ug/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2020-01-08 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.


DECISION ID	170782	Region 7
Imperial Valley Drains

Pollutant:	Pyrethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and retired. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 170782, Pyrethrin	Region 7
Imperial Valley Drains

LOE ID:

356211

Pollutant:

Pyrethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pyrethrin is the USEPA Aquatic Life Benchmark of 0.04 ug/L for freshwater invertebrates (chronic) and is the sum of pyrethrin-1 and pyrethrin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.


DECISION ID	171951	Region 7
Imperial Valley Drains

Pollutant:	Pyrethrins
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171951, Pyrethrins	Region 7
Imperial Valley Drains

LOE ID:

356235

Pollutant:

Pyrethrins

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for pyrethrins is the USEPA Aquatic Life Benchmark of 0.04 ug/L for an invertebrate (chronic), and is the sum of cinerin-1, cinerin-2, jasmolin-1, jasmolin-2, pyrethrin-1, and pyrethrin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156201	Region 7
Imperial Valley Drains

Pollutant:	Secbumeton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156201, Secbumeton	Region 7
Imperial Valley Drains

LOE ID:

319477

Pollutant:

Secbumeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Atroton, Prometon, or Secbumeton for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156145	Region 7
Imperial Valley Drains

Pollutant:	Silver
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. The number of measured exceedances is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicant pollutants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that this water segment-pollutant combination should not be placed on the CWA section 303(d) List. Refer to the lines of evidence in this fact sheet for the data and information, sample counts and exceedances, quality assurance documentation, beneficial uses, and water quality objectives or numeric evaluation guidelines relied upon for this decision.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 156145, Silver	Region 7
Imperial Valley Drains

LOE ID:

127532

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 1 of 56 samples exceeded the water quality standard for Silver.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion maximum concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156145, Silver	Region 7
Imperial Valley Drains

LOE ID:

355292

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156145, Silver	Region 7
Imperial Valley Drains

LOE ID:

5063

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) Hardness Dependent Criterion Maximum Concentrations (CMC) for the protection of freshwater aquatic life (USEPA, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156145, Silver	Region 7
Imperial Valley Drains

LOE ID:

336227

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156145, Silver	Region 7
Imperial Valley Drains

LOE ID:

319386

Pollutant:

Silver

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Aluminum, Manganese, or Silver for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156145, Silver	Region 7
Imperial Valley Drains

LOE ID:

355283

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156199	Region 7
Imperial Valley Drains

Pollutant:	Simetryn
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156199, Simetryn	Region 7
Imperial Valley Drains

LOE ID:

319820

Pollutant:

Simetryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ametryn, Prometryn, Simetryn, or Terbutryn for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156187	Region 7
Imperial Valley Drains

Pollutant:	Sulfotep
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156187, Sulfotep	Region 7
Imperial Valley Drains

LOE ID:

320751

Pollutant:

Sulfotep

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171950	Region 7
Imperial Valley Drains

Pollutant:	T-Fluvalinate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171950, T-Fluvalinate	Region 7
Imperial Valley Drains

LOE ID:

355300

Pollutant:

T-Fluvalinate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for tau-fluvalinate is the USEPA Aquatic Life Benchmark of 0.064 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7


DECISION ID	171976	Region 7
Imperial Valley Drains

Pollutant:	Tebufenozide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171976, Tebufenozide	Region 7
Imperial Valley Drains

LOE ID:

355303

Pollutant:

Tebufenozide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for tebufenozide is the USEPA Aquatic Life Benchmark of 29 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2015-10-13 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171976, Tebufenozide	Region 7
Imperial Valley Drains

LOE ID:

355309

Pollutant:

Tebufenozide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for tebufenozide is the USEPA Aquatic Life Benchmark of 29 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2015-10-13 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171976, Tebufenozide	Region 7
Imperial Valley Drains

LOE ID:

355308

Pollutant:

Tebufenozide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for tebufenozide is the USEPA Aquatic Life Benchmark of 29 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2015-10-13 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 171976, Tebufenozide	Region 7
Imperial Valley Drains

LOE ID:

355302

Pollutant:

Tebufenozide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for tebufenozide is the USEPA Aquatic Life Benchmark of 29 ug/L for an invertebrate (chronic).

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2015-10-13 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	156194	Region 7
Imperial Valley Drains

Pollutant:	Tedion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156194, Tedion	Region 7
Imperial Valley Drains

LOE ID:

320524

Pollutant:

Tedion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156194, Tedion	Region 7
Imperial Valley Drains

LOE ID:

319468

Pollutant:

Tedion

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Oxychlordane, Perylene, or Tedion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156147	Region 7
Imperial Valley Drains

Pollutant:	Terbufos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available Multi-pollutant LOEs were removed and replaced by single-pollutant LOEs to comply with modern database requirements. Detailed information is included in the replacement LOE(s).

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156147, Terbufos	Region 7
Imperial Valley Drains

LOE ID:

127968

Pollutant:

Terbufos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Terbufos. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for Terbufos is the USEPA Aquatic Life Benchmark of 0.03 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Temporal Representation:

Date for this waterbody was collected over the date range 2012-05-07 to 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 156147, Terbufos	Region 7
Imperial Valley Drains

LOE ID:

319805

Pollutant:

Terbufos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Benzo(g,h,i)Perylene, Benzo(e)Pyrene, Biphenyl, or Terbufos for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156204	Region 7
Imperial Valley Drains

Pollutant:	Terbuthylazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156204, Terbuthylazine	Region 7
Imperial Valley Drains

LOE ID:

319274

Pollutant:

Terbuthylazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Propazine, or Terbuthylazine for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156200	Region 7
Imperial Valley Drains

Pollutant:	Terbutryn
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156200, Terbutryn	Region 7
Imperial Valley Drains

LOE ID:

319821

Pollutant:

Terbutryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ametryn, Prometryn, Simetryn, or Terbutryn for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156148	Region 7
Imperial Valley Drains

Pollutant:	Tetrachlorvinphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156148, Tetrachlorvinphos	Region 7
Imperial Valley Drains

LOE ID:

320737

Pollutant:

Tetrachlorvinphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Chlorfenvinphos, Cuomaphos, Dicrotophos, Fenchchlorphos, Dyfonate, Leptophos, Merphos, Mevinphos, Tetrachlorvinphos, or Chlorpyrifos Methyl for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	171952	Region 7
Imperial Valley Drains

Pollutant:	Tetramethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171952, Tetramethrin	Region 7
Imperial Valley Drains

LOE ID:

355312

Pollutant:

Tetramethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for tetramethrin is the USEPA Aquatic Life Benchmark of 1.85 ug/L for a fish (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	171955	Region 7
Imperial Valley Drains

Pollutant:	Thiacloprid
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171955, Thiacloprid	Region 7
Imperial Valley Drains

LOE ID:

355316

Pollutant:

Thiacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiacloprid is the USEPA Aquatic Life Benchmark of 0.97 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171955, Thiacloprid	Region 7
Imperial Valley Drains

LOE ID:

355317

Pollutant:

Thiacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiacloprid is the USEPA Aquatic Life Benchmark of 0.97 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171955, Thiacloprid	Region 7
Imperial Valley Drains

LOE ID:

355321

Pollutant:

Thiacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiacloprid is the USEPA Aquatic Life Benchmark of 0.97 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171955, Thiacloprid	Region 7
Imperial Valley Drains

LOE ID:

355322

Pollutant:

Thiacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiacloprid is the USEPA Aquatic Life Benchmark of 0.97 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171955, Thiacloprid	Region 7
Imperial Valley Drains

LOE ID:

355320

Pollutant:

Thiacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiacloprid is the USEPA Aquatic Life Benchmark of 0.97 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171955, Thiacloprid	Region 7
Imperial Valley Drains

LOE ID:

355314

Pollutant:

Thiacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiacloprid is the USEPA Aquatic Life Benchmark of 0.97 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171955, Thiacloprid	Region 7
Imperial Valley Drains

LOE ID:

355315

Pollutant:

Thiacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiacloprid is the USEPA Aquatic Life Benchmark of 0.97 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	171974	Region 7
Imperial Valley Drains

Pollutant:	Thiamethoxam
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 171974, Thiamethoxam	Region 7
Imperial Valley Drains

LOE ID:

355325

Pollutant:

Thiamethoxam

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiamethoxam is the USEPA Aquatic Life Benchmark of 0.74 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171974, Thiamethoxam	Region 7
Imperial Valley Drains

LOE ID:

355326

Pollutant:

Thiamethoxam

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiamethoxam is the USEPA Aquatic Life Benchmark of 0.74 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171974, Thiamethoxam	Region 7
Imperial Valley Drains

LOE ID:

355327

Pollutant:

Thiamethoxam

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiamethoxam is the USEPA Aquatic Life Benchmark of 0.74 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171974, Thiamethoxam	Region 7
Imperial Valley Drains

LOE ID:

355328

Pollutant:

Thiamethoxam

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiamethoxam is the USEPA Aquatic Life Benchmark of 0.74 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2020-10-27

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171974, Thiamethoxam	Region 7
Imperial Valley Drains

LOE ID:

355330

Pollutant:

Thiamethoxam

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiamethoxam is the USEPA Aquatic Life Benchmark of 0.74 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171974, Thiamethoxam	Region 7
Imperial Valley Drains

LOE ID:

355332

Pollutant:

Thiamethoxam

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiamethoxam is the USEPA Aquatic Life Benchmark of 0.74 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 171974, Thiamethoxam	Region 7
Imperial Valley Drains

LOE ID:

355331

Pollutant:

Thiamethoxam

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for thiamethoxam is the USEPA Aquatic Life Benchmark of 0.74 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2020-10-28

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156195	Region 7
Imperial Valley Drains

Pollutant:	Thionazin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156195, Thionazin	Region 7
Imperial Valley Drains

LOE ID:

320525

Pollutant:

Thionazin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156188	Region 7
Imperial Valley Drains

Pollutant:	Tokuthion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156188, Tokuthion	Region 7
Imperial Valley Drains

LOE ID:

320946

Pollutant:

Tokuthion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Ethion, Carbophenothion, Dichlofenthion, Dioxathion, Parathion, Fenitrothion, Fensulfothion, Fenthion, Malathion, Methidathion, Methyl Parathion, or Tokuthion for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156149	Region 7
Imperial Valley Drains

Pollutant:	Total Dissolved Solids
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

321361

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

One water sample was collected 1/14/2020 from the following Imperial Valley Drain location: Station Code 723STRDRN. The sample did not exceed the Basin Plan objective for total dissolved solids of 4000 mg/L to protect the WA beneficial use.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Any discharge, excepting discharges from agricultural sources, shall not cause concentration of total dissolved solids (TDS) in surface waters to exceed the following limits of TDS (mg/L): Annual Average 4000, Maximum 4500

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

A sample was collected from the following Imperial Valley Drain location: Station Code 723STRDRN.

Temporal Representation:

One water sample was collected 1/14/2020 from the following Imperial Valley Drain location: Station Code 723STRDRN.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2009

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

321367

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

One water sample was collected 1/8/2020 from the following Imperial Valley Drain location: Station Code 723IPYG46. The sample did not exceed the Basin Plan objective for total dissolved solids of 4500 mg/L to protect the WA beneficial use.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

A sample was collected from the following Imperial Valley Drain location: Station Code 723IPYG46.

Temporal Representation:

One water sample was collected 1/8/2020 from the following Imperial Valley Drain location: Station Code 723IPYG46.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2009

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

321372

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

One water sample was collected 10/26/2016 from the following Imperial Valley Drain location: Station Code 723SSDS02. The sample did not exceed the Basin Plan objective for total dissolved solids of 4500 mg/L to protect the WA beneficial use.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

A sample was collected from the following Imperial Valley Drain location: Station Code 723SSDS02.

Temporal Representation:

One water sample was collected 10/26/2016 from the following Imperial Valley Drain location: Station Code 723SSDS02.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2009

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

321373

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

One water sample was collected 10/26/2016 from the following Imperial Valley Drain location: Station Code 728SSDS01. The sample did not exceed the Basin Plan objective for total dissolved solids of 4500 mg/L to protect the WA beneficial use.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

A sample was collected from the following Imperial Valley Drain location: Station Code 728SSDS01.

Temporal Representation:

One water sample was collected 10/26/2016 from the following Imperial Valley Drain location: Station Code 728SSDS01.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2009

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

321360

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

One water sample (365-day-avg) was collected 4/8/2019 to 1/7/2020 from the following Imperial Valley Drain location: Station Code 723SSDS03. The sample did not exceed the Basin Plan objective for total dissolved solids of 4000 mg/L to protect the WA beneficial use.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

A sample was collected from the following Imperial Valley Drain location: Station Code 723SSDS03.

Temporal Representation:

One water sample (365-day-avg) was collected 4/8/2019 to 1/7/2020 from the following Imperial Valley Drain location: Station Code 723SSDS03.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2009

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

321354

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

A sample was collected from the following Imperial Valley Drain location: Station Code 723IPYG46.

Temporal Representation:

One water sample was collected 1/8/2020 from the following Imperial Valley Drain location: Station Code 723IPYG46.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2009

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

321359

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

A sample was collected from the following Imperial Valley Drain location: Station Code 723SSDS02.

Temporal Representation:

One water sample was collected 10/26/2016 from the following Imperial Valley Drain location: Station Code 723SSDS02.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2009

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

125377

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of the 2 samples exceeded the maximum concentration objective and none exceeded the annual average objective.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The site-pecific objective for Total Dissolved Solids (TDS) in the Colorado River Basin Plan on page 3-3, includes an annual average of 4000 mg/L and a maximum of 4500 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at station 728SSDS01, Salton Sea Drain S1 (W Drain).

Temporal Representation:

Samples were collected on 4/22/2013, and 10/21/2013.

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

321362

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

A sample was collected from the following Imperial Valley Drain location: Station Code 728SSDS01.

Temporal Representation:

One water sample was collected 10/26/2016 from the following Imperial Valley Drain location: Station Code 723S728SSDS01TRDRN.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2009

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

321376

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

A sample was collected from the following Imperial Valley Drain location: Station Code 723STRDRN.

Temporal Representation:

One water sample was collected 1/14/2020 from the following Imperial Valley Drain location: Station Code 723STRDRN.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2009

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156149, Total Dissolved Solids	Region 7
Imperial Valley Drains

LOE ID:

321375

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Two water samples were collected 4/8/2019 to 1/7/2020 from the following Imperial Valley Drain location: Station Code 723SSDS03. The samples did not exceed the Basin Plan objective for total dissolved solids of 4500 mg/L to protect the WA beneficial use.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Two samples were collected from the following Imperial Valley Drain location: Station Code 723SSDS03.

Temporal Representation:

Two water samples were collected 4/8/2019 to 1/7/2020 from the following Imperial Valley Drain location: Station Code 723SSDS03.

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2009

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156151	Region 7
Imperial Valley Drains

Pollutant:	Trichlorfon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156151, Trichlorfon	Region 7
Imperial Valley Drains

LOE ID:

320526

Pollutant:

Trichlorfon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156196	Region 7
Imperial Valley Drains

Pollutant:	Trichloronate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156196, Trichloronate	Region 7
Imperial Valley Drains

LOE ID:

320527

Pollutant:

Trichloronate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of Oxychlordane, Perylene, Phorate, Phosmet, Phosphamidon, Sulfotep, Tedion, Thionazin, Trichloronate, or Trichlorfon for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156152	Region 7
Imperial Valley Drains

Pollutant:	Zinc
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

127951

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

4969

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Consensus Based Sediment Quality Guideline Probable Effects Concentration (PEC) of 459 mg/kg for the protection of freshwater organisms to toxic effects (Macdonald et al, 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five sediment samples were collected. Sediment samples were generally collected and analyzed twice, in May and October of 2002.Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

319719

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Five water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002. Samples were not collected from each location every sampling round.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

355356

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

353866

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRFGDN (New River at Fig Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

336413

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2019-10-16

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

353862

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-10 to 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

353871

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2018-11-14 to 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

353860

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-08 to 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

333748

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for zinc is the probable effect concentration (PEC) of 459 mg/kg dry weight (MacDonald et al., 2000a).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-04-09 to 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 156152, Zinc	Region 7
Imperial Valley Drains

LOE ID:

355363

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156189	Region 7
Imperial Valley Drains

Pollutant:	alpha-Chlordene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156189, alpha-Chlordene	Region 7
Imperial Valley Drains

LOE ID:

319292

Pollutant:

alpha-Chlordene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of alpha-Chlordene, or gamma-Chlordene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156189, alpha-Chlordene	Region 7
Imperial Valley Drains

LOE ID:

319269

Pollutant:

alpha-Chlordene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of alpha-Chlordene, or gamma-Chlordene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156109	Region 7
Imperial Valley Drains

Pollutant:	alpha-Endosulfan (Endosulfan 1)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 156109, alpha-Endosulfan (Endosulfan 1)	Region 7
Imperial Valley Drains

LOE ID:

127471

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endosulfan I criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for alpha-endosulfan is 0.056 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156109, alpha-Endosulfan (Endosulfan 1)	Region 7
Imperial Valley Drains

LOE ID:

354506

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endosulfan I criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for alpha-endosulfan is 0.056 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 156109, alpha-Endosulfan (Endosulfan 1)	Region 7
Imperial Valley Drains

LOE ID:

128182

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endosulfan I criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for alpha-endosulfan is 0.056 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156109, alpha-Endosulfan (Endosulfan 1)	Region 7
Imperial Valley Drains

LOE ID:

319497

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Endosulfan 1, Endosulfan 2, or Endosulfan Sulfate for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156109, alpha-Endosulfan (Endosulfan 1)	Region 7
Imperial Valley Drains

LOE ID:

320050

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156094	Region 7
Imperial Valley Drains

Pollutant:	alpha.-BHC (Benzenehexachloride or alpha-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156094, alpha.-BHC (Benzenehexachloride or alpha-HCH)	Region 7
Imperial Valley Drains

LOE ID:

319631

Pollutant:

alpha.-BHC (Benzenehexachloride or alpha-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of alpha-HCH, beta-HCH, Hexachlorobenzene, or Methoxychlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156127	Region 7
Imperial Valley Drains

Pollutant:	beta-BHC (Benzenehexachloride or beta-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156127, beta-BHC (Benzenehexachloride or beta-HCH)	Region 7
Imperial Valley Drains

LOE ID:

319632

Pollutant:

beta-BHC (Benzenehexachloride or beta-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of alpha-HCH, beta-HCH, Hexachlorobenzene, or Methoxychlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156139	Region 7
Imperial Valley Drains

Pollutant:	beta-Endosulfan (Endosulfan 2)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 156139, beta-Endosulfan (Endosulfan 2)	Region 7
Imperial Valley Drains

LOE ID:

354513

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endosulfan II criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for beta-endosulfan is 0.056 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 156139, beta-Endosulfan (Endosulfan 2)	Region 7
Imperial Valley Drains

LOE ID:

319498

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of Endosulfan 1, Endosulfan 2, or Endosulfan Sulfate for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156139, beta-Endosulfan (Endosulfan 2)	Region 7
Imperial Valley Drains

LOE ID:

127641

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endosulfan II criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for beta-endosulfan is 0.056 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2012-10-17

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156139, beta-Endosulfan (Endosulfan 2)	Region 7
Imperial Valley Drains

LOE ID:

127813

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for RWB7 TMDL.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endosulfan II criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for beta-endosulfan is 0.056 ug/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (723CNTDRN)

Temporal Representation:

The samples were collected between the dates of 2011-02-11 and 2011-02-11

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 156139, beta-Endosulfan (Endosulfan 2)	Region 7
Imperial Valley Drains

LOE ID:

320051

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains. Of these total samples, none exceeded the CTR Criteria (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156161	Region 7
Imperial Valley Drains

Pollutant:	cis-Nonachlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156161, cis-Nonachlor	Region 7
Imperial Valley Drains

LOE ID:

319334

Pollutant:

cis-Nonachlor

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of cis-Nonachlor, or trans-Nonachlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156161, cis-Nonachlor	Region 7
Imperial Valley Drains

LOE ID:

319265

Pollutant:

cis-Nonachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of cis-Nonachlor, or trans-Nonachlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	156190	Region 7
Imperial Valley Drains

Pollutant:	gama-Chlordene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156190, gama-Chlordene	Region 7
Imperial Valley Drains

LOE ID:

319270

Pollutant:

gama-Chlordene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of alpha-Chlordene, or gamma-Chlordene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156190, gama-Chlordene	Region 7
Imperial Valley Drains

LOE ID:

319293

Pollutant:

gama-Chlordene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of alpha-Chlordene, or gamma-Chlordene for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	159217	Region 7
Imperial Valley Drains

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for conventional or other pollutants (Table 3.2 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards for the pollutant are not exceeded.

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355128

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Colorado River Basin Region's water quality objective for all surface waters states the following: Since the regional waters are somewhat alkaline, pH shall range from 6.0-9.0. Discharges shall not cause any changes in pH detrimental to beneficial water uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336067

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355161

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355160

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS02 (Salton Sea Drain S2 (Niland 4)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355159

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355121

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355162

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRFGDN (New River at Fig Drain).

Temporal Representation:

The samples were collected between the dates of 2018-11-14 and 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355150

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335947

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355132

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355147

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355137

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355133

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

The samples were collected between the dates of 2018-11-14 and 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355127

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PEACHD (Peach Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355143

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355124

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355148

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355144

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355156

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

5118

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality measurements were collected and analyzed twice in 2002 at 3 locations in Imperial Valley drains. Of these total measurements, none exceeded the Basin Plan Objective (SWAMP, 2007).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: Since the regional waters are somewhat alkaline, pH shall range from 6.0-9.0 (CRBRWQCB, 2006).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Measurements were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six measurements were collected. Measurements were generally collected and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

127708

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Freshwater Replenishment

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and results are as follows: 0 of 76 samples exceeded the water quality standard for pH.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

128592

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

127322

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

127318

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

The samples were collected between the dates of 2012-05-07 and 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336084

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

The samples were collected between the dates of 2018-11-14 and 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335961

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335962

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRFGDN (New River at Fig Drain).

Temporal Representation:

The samples were collected between the dates of 2018-11-14 and 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336089

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335844

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335995

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336125

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335872

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336002

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PEACHD (Peach Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335882

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335883

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336013

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335887

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336022

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335918

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Freshwater Replenishment

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336076

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335912

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS02 (Salton Sea Drain S2 (Niland 4)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336059

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336065

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723STRDRN (R Drain Tributary at Alcott and wister road).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2020-01-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335820

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335821

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335950

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS03 (Salton Sea Drain S3 (Trifolium TD1)).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2020-01-07

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335963

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRFGDN (New River at Fig Drain).

Temporal Representation:

The samples were collected between the dates of 2018-11-14 and 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335966

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723NRGNDN (New River at Greeson Drain).

Temporal Representation:

The samples were collected between the dates of 2018-11-14 and 2018-11-14

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336090

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335970

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335848

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CC0065 (Fig Drain ~1.2mi N Westside Main Canal).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335851

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CNTDRN (Central Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335977

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336109

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2019-04-09 and 2020-01-08

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336116

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARWDR (Barbara Worth Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-28 and 2022-04-25

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335993

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336004

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PEACHD (Peach Drain).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336132

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335888

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335911

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SSDS02 (Salton Sea Drain S2 (Niland 4)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

336053

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2016-10-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

335927

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159217, pH	Region 7
Imperial Valley Drains

LOE ID:

355131

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2020-10-27 and 2022-04-26

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006


DECISION ID	156162	Region 7
Imperial Valley Drains

Pollutant:	trans-Nonachlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 156162, trans-Nonachlor	Region 7
Imperial Valley Drains

LOE ID:

319335

Pollutant:

trans-Nonachlor

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Five sediment quality samples were collected and analyzed in May and October of 2002 at 3 locations along Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. There shall be no increase in hazardous chemical concentrations found in bottom sediments or aquatic life (CRBRWQCB, 2006).No evaluation guidelines for the sediment fractions of cis-Nonachlor, or trans-Nonachlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 156162, trans-Nonachlor	Region 7
Imperial Valley Drains

LOE ID:

319266

Pollutant:

trans-Nonachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Six water quality samples were collected and analyzed in May and October 2002 at 3 locations in Imperial Valley Drains (SWAMP, 2006).

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Basin Plan: No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses (CRBRWQCB, 2006).No evaluation guidelines for the dissolved fractions of cis-Nonachlor, or trans-Nonachlor for the protection of human, animal or aquatic life in fresh waters could be found that met the requirements of Section 6.1.3 of the Listing Policy.

Objective/Criterion Reference:

Water Quality Control Plan Colorado River Basin, with amendments adopted through June 2006

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from three Imperial Valley Drains ;Trifolium TD1, Niland 4, and W.

Temporal Representation:

Six water samples were collected. Water samples were generally collected from all three sampling locations and analyzed twice, in May and October of 2002.

Environmental Conditions:

QAPP Information:

The sampling and analysis portions of this study were conducted in accordance with the SWAMP Quality Assurance Management Plan (QAMP) (Puckett, 2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	159223	Region 7
Imperial Valley Drains

Pollutant:	Bifenthrin
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Forty-four lines of evidence are available in the administrative record to assess this pollutant. 7 of the 7 water samples exceed the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 5 of 5 water samples with a nonreported fraction exceed the CRITERIA and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 3. 3 of 3 total fraction water samples exceed the CRITERIA and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

125457

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 1 of the 25 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 26 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin from Amweg et al. (2005) and Amweg and Weston (2007).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

351636

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The chronic criterion for bifenthrin is 0.1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of bifenthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355420

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354119

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354128

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355402

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355405

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355407

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355410

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355427

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355413

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355433

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355434

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355446

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354118

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355398

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355404

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355415

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355445

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355393

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

353617

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MTSIGD (Mount Signal Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

353616

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WRMWDD (Wormwood Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

353620

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354115

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354116

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355416

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355438

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354129

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355412

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355419

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BDRAIN (B Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355430

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355441

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355391

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354104

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354103

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the water quality threshold for Bifenthrin. Although a total of 7 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site (723IPHV10).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354125

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355397

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355425

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355395

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354126

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354123

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

354127

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

355396

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159223, Bifenthrin	Region 7
Imperial Valley Drains

LOE ID:

334653

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):


DECISION ID	159224	Region 7
Imperial Valley Drains

Pollutant:	Cypermethrin
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Sixty-nine lines of evidence are available in the administrative record to assess this pollutant. Eight of 8 samples exceed the water quality threshold. Four of the 24 samples exceed the sediment quality threshold but there is insufficient sediment toxicity to determine use support. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eight of 8 samples exceed the water quality threshold. This exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357504

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002).

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723KDRAIN (K Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357525

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357530

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SCENTD (South Central Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357533

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357534

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin, Total. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VAIL7D (Vail Seven Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354312

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The chronic criterion for cypermethrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of cypermethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354314

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Cypermethrin. Although a total of 3 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site (723IPVD69).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355550

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355571

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355543

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355547

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

353709

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WRMWDD (Wormwood Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355551

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355558

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354332

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355560

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355561

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354319

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355575

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355522

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355527

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

353708

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355554

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355556

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BDRAIN (B Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355578

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355524

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355549

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355562

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355563

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354321

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355525

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354329

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355540

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

353879

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723SSDS03 ( Salton Sea Drain S3 (Trifolium TD1) ).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

353919

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723STRDRN ( R Drain Tributary at Alcott and wister road ).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-04-10.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

334899

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355544

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355531

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355535

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355541

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

353711

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin, Total. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MTSIGD (Mount Signal Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354315

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Cypermethrin. Although a total of 7 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site (723IPHV10).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354317

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355573

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354327

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

355537

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354323

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354324

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

354335

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 3 of the 3 samples exceeded the water quality threshold for Cypermethrin. Although a total of 7 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site (723ST1252).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

351708

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

348840

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program Â

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357500

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CENTD3 (Central Drain Three).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357510

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PMLEOD (Pomelo Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357519

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357529

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WILDCD (Wildcat Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357508

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723OSAGED (Osage Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-04 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357501

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723BDRAIN (B Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357514

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VERDED (Verde Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357536

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357521

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MCALD1 (McCall Drain One).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357531

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723THIS5D (Thistle Five Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357502

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CENTD2 (Central Drain Two).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357505

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PAMPAD (Pampas Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357507

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723OLANDR (Oleander Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-04 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357511

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357517

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357518

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357520

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MARIGD (Marigold Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159224, Cypermethrin	Region 7
Imperial Valley Drains

LOE ID:

357528

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin, Total. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723EDRAIN (E Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	159230	Region 7
Imperial Valley Drains

Pollutant:	Esfenvalerate/Fenvalerate
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. 44 lines of evidence are available in the administrative record to assess this pollutant. 8 of the 8 water samples exceed the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 6 of 6 total fraction water samples exceed the CRITERIA and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. 2 of 2 water samples without a fraction recorded exceed the CRITERIA and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355686

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in human, plant, animal, or aquatic life (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The chronic criterion for esfenvalerate is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of esfenvalerate were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355707

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355711

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355671

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355673

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355676

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354554

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

353742

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate (Amweg et al., 2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MTSIGD (Mount Signal Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355715

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354538

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355675

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354556

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355703

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BDRAIN (B Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354535

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the water quality threshold for Esfenvalerate. Although a total of 7 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site (723IPHV10).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355726

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354537

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355680

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355702

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

353743

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355708

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355716

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355719

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354551

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354546

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354553

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355709

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354548

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354550

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355678

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355681

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354555

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355691

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355694

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355698

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

353741

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WRMWDD (Wormwood Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355724

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355714

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

354552

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355693

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355697

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

355705

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

125420

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 1 of the 23 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total .

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before January 8, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 23 (Station Codes: 723BDRAIN, 723CENTD2, 723CENTD3, 723CTD3MA, 723EDRAIN, 723ELML6D, 723KDRAIN, 723MARIGD, 723MCALD1, 723OLANDR, 723OSAGED, 723PAM115, 723PAMPAD, 723PMLEOD, 723QLATDR, 723SCENTD, 723THIS5D, 723TRI12D, 723UADCMC, 723UADGUN, 723VAIL7D, 723VERDED, 723WILDCD).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

335182

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159230, Esfenvalerate/Fenvalerate	Region 7
Imperial Valley Drains

LOE ID:

351765

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7


DECISION ID	159231	Region 7
Imperial Valley Drains

Pollutant:	Permethrin
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Sixty-eight lines of evidence are available in the administrative record to assess this pollutant. Eight of the 8 water samples exceed the UC Davis criteria. LOE 125618 & 128044 has been replaced by LOE 335793, 351896 & 348848 due to a reassessment of data. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 8 of 8 water samples exceed the UC Davis criteria and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355104

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The chronic criterion for permethrin is 1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of permethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355114

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

353828

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin (Amweg et al., 2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

335793

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356061

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356080

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355105

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356038

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356063

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356073

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356083

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355098

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356070

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356090

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356050

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356059

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356072

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BDRAIN (B Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356088

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355092

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355101

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356048

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356062

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356078

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356079

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355099

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and the results are as follows: 3 of the 3 samples exceeded the water quality threshold for Permethrin. Although a total of 7 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site (723IPHV10).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

351896

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

348848

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program Â

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357593

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PAMPAD (Pampas Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357592

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723BDRAIN (B Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357596

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357603

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CENTD2 (Central Drain Two).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357611

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357591

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723OLANDR (Oleander Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-04 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357613

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357623

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WILDCD (Wildcat Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357609

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723THIS5D (Thistle Five Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357601

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357583

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723OSAGED (Osage Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-04 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357616

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PAM115 (Pampas Drain near 115).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357600

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VAIL7D (Vail Seven Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357594

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723EDRAIN (E Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357585

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357606

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MARIGD (Marigold Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357590

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357589

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SCENTD (South Central Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357595

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723KDRAIN (K Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357584

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MCALD1 (McCall Drain One).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357622

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PMLEOD (Pomelo Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357605

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VERDED (Verde Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357602

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CENTD3 (Central Drain Three).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

357610

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356044

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355110

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355112

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356041

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356060

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356065

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355100

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355089

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

353827

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WRMWDD (Wormwood Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

353830

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the Colorado River Basin Region)

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MTSIGD (Mount Signal Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356037

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356040

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356093

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356042

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356051

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

356067

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159231, Permethrin	Region 7
Imperial Valley Drains

LOE ID:

355094

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):


DECISION ID	159221	Region 7
Imperial Valley Drains

Pollutant:	Pyrethroids
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 two lines of evidence is necessary to assess listing status. Eighty-six lines of evidence are available in the administrative record to assess this pollutant. LOE 125451 & 127374 has been replaced by LOE 351993, 336157, 351991, 336160, 348857 due to a reassessment of data. Twenty-seven of the 27 water samples exceed the toxic unit equivalent (Department of Fish and Game Aquatic Life Criteria for Pyrethroid Insecticides, 2000, UC Davis Aquatic Life Criteria for Pyrethroid Insecticides, 2012) Six of the 28 sediment samples exceed the toxic unit equivalent (Department of Fish and Game Aquatic Life Criteria for Pyrethroid Insecticides, 2000, UC Davis Aquatic Life Criteria for Pyrethroid Insecticides, 2012) but insufficient sediment toxicity is present in the water segment to determine use support. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3.Twenty-seven of the 27water samples exceed the toxic unit equivalent (Department of Fish and Game Aquatic Life Criteria for Pyrethroid Insecticides, 2000, UC Davis Aquatic Life Criteria for Pyrethroid Insecticides, 2012). This exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357643

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MCALD1 (McCall Drain One).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357635

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357654

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MARIGD (Marigold Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357660

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723KDRAIN (K Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357627

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CENTD3 (Central Drain Three).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357626

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357640

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VAIL7D (Vail Seven Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357632

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WILDCD (Wildcat Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357656

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CENTD2 (Central Drain Two).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357625

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357648

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357665

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723BDRAIN (B Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357662

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VERDED (Verde Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357628

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PAMPAD (Pampas Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355208

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

The summed ratios of the pyrethroid pesticides bifenthrin, cyfluthrin, cypermethrin, esfenvalerate, lambda-cyhalothrin, permethrin and their respective chronic concentration goals are not to exceed 1. If the freely dissolved concentrations of these pesticides were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355235

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356290

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723ELML6D (Elm Lateral Six Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356295

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723WILDCD (Wildcat Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356288

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723OASISD (Oasis Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356294

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD2 (Central Drain Two).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356301

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 728SSDS01 (Salton Sea Drain S1 (W Drain)).

Temporal Representation:

The samples were collected between the dates of 2013-04-22 and 2013-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356317

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723SPRUCD (Spruce Drain 0.5 miles from Frdericks Rd. and Kalin Rd. and Brandt Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355205

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356300

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356279

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356281

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355209

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355242

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355246

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723MTSIGD (Mount Signal Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356305

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723THIS5D (Thistle Five Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355210

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Pyrethroids.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2015-10-13 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356313

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723CENTD3 (Central Drain Three).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356273

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAMPAD (Pampas Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355207

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356241

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723EDRAIN (E Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356280

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355247

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355261

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356312

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

353879

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723SSDS03 ( Salton Sea Drain S3 (Trifolium TD1) ).

Temporal Representation:

The samples were collected between the dates of 2019-04-08 and 2019-10-15.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

353919

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at monitoring site: 723STRDRN ( R Drain Tributary at Alcott and wister road ).

Temporal Representation:

The samples were collected between the dates of 2019-04-10 and 2019-04-10.

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355226

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IMWLIN (Imperial Wetlands Inlet).

Temporal Representation:

The samples were collected between the dates of 2017-07-11 and 2017-07-11

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355241

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

353848

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723MTSIGD (Mount Signal Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356236

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723OSAGED (Osage Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356275

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723PAM115 (Pampas Drain near 115).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356255

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723BDRAIN (B Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356264

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723MCALD1 (McCall Drain One).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356285

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723VERDED (Verde Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355230

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355240

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355249

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355252

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723WRMWDD (Wormwood Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355215

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 4 of 4 samples exceeded the water quality threshold for Pyrethroids.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356257

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355222

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2016-10-26 and 2017-10-17

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355229

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 5 of 5 samples exceeded the water quality threshold for Pyrethroids.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2017-03-21

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356247

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAIL7D (Vail Seven Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356278

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723OLANDR (Oleander Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-04 and 2015-11-04

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356267

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356307

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723SCENTD (South Central Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

353845

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723WRMWDD (Wormwood Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

353846

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-19 to 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

336160

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

336157

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed DPR Surface Water Study 290 Name data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPYG46 (Vail Drain Near Young).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

351991

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

351993

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

348857

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723BARBWD (Barbara Worth Drain at Barbara Worth Resort and Country Club).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program Â

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357630

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PAM115 (Pampas Drain near 115).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357663

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADCMC (Unnamed Agriculture Drain near Central Main Canal).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357634

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723UADGUN (Unnamed Agriculture Drain at the intersection of Gunterman Rd. and Hwy 98).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357629

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723OSAGED (Osage Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-04 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357650

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723CTD3MA (Central Drain Three at Meloland Rd. and Abatti Rd.).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357647

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723OLANDR (Oleander Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-04 to 2015-11-04

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357641

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723SCENTD (South Central Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357661

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723THIS5D (Thistle Five Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-20 to 2015-10-20

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357624

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723PMLEOD (Pomelo Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-11-03 to 2015-11-03

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

357652

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 723EDRAIN (E Drain).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-10-21 to 2015-10-21

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356254

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723PMLEOD (Pomelo Drain).

Temporal Representation:

The samples were collected between the dates of 2015-11-03 and 2015-11-03

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356269

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723UADSPC (Unnamed Agriculture Drain near New Spruce Canal).

Temporal Representation:

The samples were collected between the dates of 2015-10-20 and 2015-10-20

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356283

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723VAL2AD (Vail Two-A Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355218

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2012-10-09 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355214

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Toxicity, WQ from the DPR Surface Water Study 290 Program for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPRC99 (Rice Drain III at Weinert).

Temporal Representation:

The samples were collected between the dates of 2014-10-15 and 2014-10-15

Environmental Conditions:

QAPP Information:

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

QAPP Information Reference(s):

Department of Pesticide Regulation (DPR) QAPP Equivalent Documentation 2026

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

355225

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 7

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723VALCOD (Vail Cut Off Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-19 and 2015-10-19

Environmental Conditions:

QAPP Information:

General SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356293

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723MARIGD (Marigold Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB7 Monitoring.

Line of Evidence (LOE) for Decision ID 159221, Pyrethroids	Region 7
Imperial Valley Drains

LOE ID:

356272

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB7 Monitoring data for Imperial Valley Drains to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Colorado River Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Spatial Representation:

The samples were collected at 1 monitoring site: 723KDRAIN (K Drain).

Temporal Representation:

The samples were collected between the dates of 2015-10-21 and 2015-10-21

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7


DECISION ID	171961	Region 7
Imperial Valley Drains

Pollutant:	Trifluralin
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. 4 of the 20 samples exceed the UC Davis CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 4 of 20 samples exceed the CRITERIA and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 171961, Trifluralin	Region 7
Imperial Valley Drains

LOE ID:

355348

Pollutant:

Trifluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of Trifluralin does not exceed 0.33 ug/L in the water column more than once every three years on average (Bower, et al. 2017).

Guideline Reference:

Water Quality Criteria Report for Trifluralin Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology University of California, Davis.

Spatial Representation:

The samples were collected at 1 monitoring site: Imperial 75 (Trifolium 3 Drain at Walker).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2011-03-01

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171961, Trifluralin	Region 7
Imperial Valley Drains

LOE ID:

355350

Pollutant:

Trifluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Trifluralin Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology University of California, Davis.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPHV10 (Holtville Main Drain at 115).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171961, Trifluralin	Region 7
Imperial Valley Drains

LOE ID:

355354

Pollutant:

Trifluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 1 of 4 samples exceeded the water quality threshold for Trifluralin.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Trifluralin Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology University of California, Davis.

Spatial Representation:

The samples were collected at 1 monitoring site: 723ST1252 (Rice Drain 3-723ST1252).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171961, Trifluralin	Region 7
Imperial Valley Drains

LOE ID:

355340

Pollutant:

Trifluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Trifluralin Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology University of California, Davis.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPVD69 (Verde Drain at Bonds Corner Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691

Line of Evidence (LOE) for Decision ID 171961, Trifluralin	Region 7
Imperial Valley Drains

LOE ID:

355343

Pollutant:

Trifluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Surface Water Monitoring Project data for Imperial Valley Drains to determine beneficial use support and results are as follows: 2 of 5 samples exceeded the water quality threshold for Trifluralin.

Data Reference:

WQ from the Department of Pesticide Regulation Surface Water Monitoring for the 2026 Integrated Report in Region 7

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual chemical or combination of chemicals shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan for the Colorado River Basin Region (Includes amendments effective on or before March 30, 2019)

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Trifluralin Phase III: Application of the pesticide water quality criteria methodology. Department of Environmental Toxicology University of California, Davis.

Spatial Representation:

The samples were collected at 1 monitoring site: 723IPMV61 (Malva Drain near Park Rd).

Temporal Representation:

The samples were collected between the dates of 2011-03-01 and 2015-10-13

Environmental Conditions:

QAPP Information:

AZDEQ SW QAPP 01/2021

QAPP Information Reference(s):

CRB-RWQCB o/b/o AZDEQ - AZDEQ SW QAPP 01/2021 - AZDEQ_SW - 402691


DECISION ID	68868	Region 7
Imperial Valley Drains

Pollutant:	Sedimentation/Siltation
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Agricultural Return Flows
TMDL Name:	Imperial Valley Drains Sediment TMDL
TMDL Project Code:	14
Date TMDL Approved by USEPA:	09/30/2005
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Board Conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Line of Evidence No 2962 is a placeholder line of evidence, containing no data it is used to indicate this was a listing made prior to 2006. Based on the applicable factor, the Imperial Valley Drains sedimentation/siltation TMDL was approved by USEPA on September 30, 2005. The approved TMDL and implementation plan is expected to result in attainment of the standard. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.

Regional Board Decision Recommendation:	This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 68868, Sedimentation/Siltation	Region 7
Imperial Valley Drains

LOE ID:

2962

Pollutant:

Sedimentation/Siltation

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.

Data Reference: