Final California 2020 Integrated Report (303(d) List/305(b) Report)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water bodies shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses. (RWQCB, 2007)
A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total P. These values are not to be exceeded more than 10% of the time unless studies of the specific water body in question clearly show that water quality objective changes are permissible and changes are approved by the Regional Board. Analogous threshold values have not been set for nitrogen compounds; however, natural ratios of nitrogen to phosphorus are to be determined by surveillance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used. (RWQCB, 2007)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA

Spatial Representation:

Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.

Temporal Representation:

Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.

Environmental Conditions:

Samples were collected during wet weather.

QAPP Information:

QA/QC conducted according to Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 126467, Benthic Community Effects	Region 9
Santa Margarita River (Lower)

LOE ID:

7497

Pollutant:

Total Nitrogen as N

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 monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Five of six samples exceed the water quality objective according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected one to two times a year from 2001-2006 with the exception of the 2004-2005 monitoring year.

Data Reference:

Urban Runoff Monitoring, Volume 1- Final Report To request a file review please contact the San Diego Regional Board receptionist. They may be reached by phone at (619) 516-1990, by email at rb9_records@waterboards.ca.gov, by fax at (619) 516-1994, or mail your request to: California Regional Water Quality Control Board Attention: File Review Request 2375 Northside Drive, Suite 100 San Diego, CA 92108 The ECM document handle is #2733059

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Data for Various Pollutants from the County of San Diego Copermittees Receiving Waters Monitoring and Reporting Program, 2001-2008.

Spatial Representation:

Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.

Temporal Representation:

Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.

Environmental Conditions:

Samples were collected during wet weather.

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 126467, Benthic Community Effects	Region 9
Santa Margarita River (Lower)

LOE ID:

76544

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Eleven samples were collected to test for toxicity. Five of the eleven samples exhibited statistically significant toxicity. The toxicity tests included survival of Hyalella azteca, growth of Selenastrum capriconutum and survival and reproduction of Ceriodaphnia dubia.

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

Objective/Criterion Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. EPA-821-R-02-012

Evaluation Guideline:

Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. The t-test is used to determine if there is a statistically significant decrease in organism response in the sample as compared to the control.

Guideline Reference:

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 station 902SMR-MLS - Santa Margarita River.

Temporal Representation:

The samples were collected from 2001 to 2008.

Environmental Conditions:

QAPP Information:

The data was collected under the County of San Diego Co-Permittees Receiving Waters Urban Runoff Monitoring and Reporting Program (Order No. 2007-01). Data quality is good.

QAPP Information Reference(s):

e-mail clarifying QAPP information

Line of Evidence (LOE) for Decision ID 126467, Benthic Community Effects	Region 9
Santa Margarita River (Lower)

LOE ID:

7501

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Ambient toxicity testing (chronic)

Data Used to Assess Water Quality:

Selenastrum capricornutum-
Three samples were collected with one samples showing significant toxicity levels (SL) as determined by the Selenastrum capricornutum growth test.

Ceriodaphnia dubia-
Two samples were collected and one samples show significant toxicity levels (SL) as determined by the Ceriodaphnia dubia survival/reproductive test. A fourth sample was collected and tested however the sample temperature was received outside acceptable limits upon laboratory receipt and the results were not used in this assessment.
Hyalella azteca-
Two samples were collected and one sample shows significant toxicity levels (SL) as determined by the Hyalella azteca growth/survival test according to results in the Surface Water Ambient Monitoring Program Report, 2007. Samples were collected on the following dates: January 14, April 15, May 13, and September 9, 2003.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

From the Basin Plan, all waters shall be free of toxic substances that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (RWQCB, 2007).

Objective/Criterion Reference:

Evaluation Guideline:

According to SWAMP, waters are considered toxic when samples show significant toxicity levels (SWAMP code ¿SL¿) when compared to a negative control. Significant toxicity is determined when statistical tests result in an alpha of less than 5% and percent control values less than the evaluation threshold.

Guideline Reference:

2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA

Spatial Representation:

Samples were collected at the monitoring station Santa Margarita 10 located on the main stem of the Lower Santa Margarita River.

Temporal Representation:

Samples were collected on the following dates: January 14, April 15, May 13, and September 9, 2003.

Environmental Conditions:

QAPP Information:

Quality control for the chemical analysis portion of this study conducted in accordance with the California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 126467, Benthic Community Effects	Region 9
Santa Margarita River (Lower)

LOE ID:

215822

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Water Board staff assessed data for 902S00117 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.7168 to 0.7168 .

Data Reference:

California Stream Condition Index Scores for the 2020 Integrated Report

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 or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board. Region 9 Basin Plan.

Objective/Criterion Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Evaluation Guideline:

The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rhen, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.

Guideline Reference:

Spatial Representation:

Samples were collected from station 902S00117

Temporal Representation:

Samples were collected from 5/25/2010 to 5/25/2010.

Environmental Conditions:

QAPP Information:

Data collected following SWAMP QA protocols.

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 126467, Benthic Community Effects	Region 9
Santa Margarita River (Lower)

LOE ID:

7500

Pollutant:

Phosphorus

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 monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

All five samples exceed the water quality objective. according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected on the following dates: January 14, April 15, twice on May 13, and September 9, 2003.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water bodies shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses.
Water Quality Control Plan for the San Diego Basin has a goal of 0.1 mg/L for total phosphorus in streams and other flowing waters. (RWQCB, 2007)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The sampling site lies on the lower Santa Margarita River (Santa Margarita 10 (902SSMR10 lat/long: 33.23669/-117.39175)).

Temporal Representation:

Samples were collected on the following dates: January 14, April 15, twice on May 13, and September 9, 2003.

Environmental Conditions:

The first two sampling events occurred between storm events and high base flow respectively. The third and fourth occurred during declining and minimum base flow respectively.

QAPP Information:

Quality control for the chemical analysis portion of this study was conducted in accordance with the California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 126467, Benthic Community Effects	Region 9
Santa Margarita River (Lower)

LOE ID:

7499

Pollutant:

Phosphorus

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 monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Five of six samples exceed the water quality objective according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the San Diego Basin has a goal of 0.1 mg/L for total phosphorus in streams and other flowing waters. (RWQCB, 2007)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

Spatial Representation:

Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.

Temporal Representation:

Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.

Environmental Conditions:

Samples were collected during wet weather.

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 126467, Benthic Community Effects	Region 9
Santa Margarita River (Lower)

LOE ID:

146035

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 10 of 11 samples exceeded the water quality threshold for Phosphorus as P.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Concentrations of nitrogen and phosphorus, by themselves or in combination with other nutrients, shall be maintained at levels below those which stimulate algae and emergent plant growth. A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total P. Analogous threshold values have not been set for nitrogen compounds; however, natural ratios of nitrogen to phosphorus are to be determined by surveillance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

County of San Diego - Dept of Public Works. 2008. Quality Assurance Project Plan from Southern California Bight. ., Weston Solutions, Inc.. 2014. Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program., Wood. 2019. Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load., Weston Solutions, Inc.. 2019. Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring.

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 126467, Benthic Community Effects	Region 9
Santa Margarita River (Lower)

LOE ID:

79700

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Six samples were taken at one station in the Santa Margarita River below De Luz Creek. Two had CSCI scores below the 0.79 threshold, and therefore exceed the water quality objective for the aquatic life beneficial use.

Data Reference:

Data for Various Pollutants from the County of San Diego Copermittees Receiving Waters Monitoring and Reporting Program, 2001-2008.

RWB9 Stormwater Monitoring Council CY 2009

Region 9 CSCI Scores & Water Body Information

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at the following stations: 902SMR-CP

Temporal Representation:

The samples were collected from 2003 to 2007.

Environmental Conditions:

QAPP Information:

The data was collected under the County of San Diego NPDES MS4 Copermittees Receiving Waters Monitoring and Reporting Program.

QAPP Information Reference(s):

e-mail clarifying QAPP information

QAPP Information Reference(s):

Data for Various Pollutants from the County of San Diego Copermittees Receiving Waters Monitoring and Reporting Program, 2001-2008.

QAPP Information Reference(s):

RWB9 Stormwater Monitoring Council CY 2009

Line of Evidence (LOE) for Decision ID 126467, Benthic Community Effects	Region 9
Santa Margarita River (Lower)

LOE ID:

143980

Pollutant:

Total Nitrogen as N

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 12 of 13 samples exceeded the water quality threshold for Nitrogen, Total.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 126467, Benthic Community Effects	Region 9
Santa Margarita River (Lower)

LOE ID:

77848

Pollutant:

Chlorpyrifos

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:

State Water Board staff assessed County of San Diego data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 2 of 3 samples exceed the criterion for Chlorpyrifos. Four sample results 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:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in the water column, sediments or biota at concentration(s) that adversely affect beneficial uses. Pesticides shall not be present at levels which will bioaccumulate in aquatic organisms to levels which are harmful to human health, wildlife or aquatic organisms (Water Quality Control Plan, San Diego Basin).

Objective/Criterion 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).

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 ug/L (Siepmann and Finlayson 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Weston, The Regional Monitoring Workgroup Urban Runoff Monitoring Final Report Methods Sections and Statements of Work, and Weston Solutions Inc. Desk Reference for Quality Control Of Work Products was used.

QAPP Information Reference(s):

Quality Assurance Project Plan from Weston, The Regional Monitoring Workgroup Urban Runoff Monitoring Final Report Methods Sections and Statements of Work, and Weston Solutions Inc. Desk Reference for Quality Control Of Work Products.


DECISION ID	111241	Region 9
Santa Margarita River (Lower)

Pollutant:	Chlorpyrifos
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
Expected TMDL Completion Date:	2029
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. Five lines of evidence are available in the administrative record to assess this pollutant. Two of 16 samples exceed the water quality threshold for the WARM/COLD beneficial use. Zero of 16 samples exceed the water quality threshold for the MUN beneficial use. Zero of one sediment sample exceeds the water quality threshold for sediment; this sample size is not sufficient to determine beneficial use support with the statistical power and confidence of the Listing Policy. 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. Two of 16 samples exceeded the water qualtiy threshold for the WARM/COLD beneficial use, 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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111241, Chlorpyrifos	Region 9
Santa Margarita River (Lower)

LOE ID:

77851

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed County of San Diego data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Chlorpyrifos.

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

2011 Edition of the Drinking Water Standards and Health Advisories

Evaluation Guideline:

The USEPA drinking water health advisory for chlorpyrifos is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111241, Chlorpyrifos	Region 9
Santa Margarita River (Lower)

LOE ID:

77848

Pollutant:

Chlorpyrifos

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:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 ug/L (Siepmann and Finlayson 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111241, Chlorpyrifos	Region 9
Santa Margarita River (Lower)

LOE ID:

76475

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlorpyrifos.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the San Diego Basin (SDRWQCB 2007): 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.

Objective/Criterion Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Evaluation Guideline:

The evaluation guideline for chlorpyrifos is the median lethal concentration (LC50) of 1.77 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Amweg and Weston, 2007).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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 111241, Chlorpyrifos	Region 9
Santa Margarita River (Lower)

LOE ID:

141438

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Chlorpyrifos.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

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:

2018 Edition of the Drinking Water Standards and Health Advisories

Evaluation Guideline:

The 2018 USEPA drinking water health advisory for chlorpyrifos is 2 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111241, Chlorpyrifos	Region 9
Santa Margarita River (Lower)

LOE ID:

219702

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 13 samples exceeded the water quality threshold for Chlorpyrifos.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

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:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (4 day average)(Siepmann and Finlayson 2000).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111241, Chlorpyrifos	Region 9
Santa Margarita River (Lower)

LOE ID:

219683

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

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:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (4 day average)(Siepmann and Finlayson 2000).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	128036	Region 9
Santa Margarita River (Lower)

Pollutant:	Indicator Bacteria
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
Expected TMDL Completion Date:	2025
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 4.3 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Zero lines of evidence is available in the administrative record to assess this pollutant. This sample size is insufficient to determine beneficial use support with the statistical power and confidence required by the Listing Policy; the minimum sample size necessary to delist is 26. 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. No new data is available, and this sample size is insufficient information in Table 4.2. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies Therefore, this waterbody is being considered for placement on or removal from the CWA section 303(d) List under section 3.3 or 4.3 of the Listing Policy, as applicable, using the E. coli objective. In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Indicator bacteria (total coliform, fecal coliform, E. coli, enterococci) populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, they do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of indicator bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address bacteria. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the list, which could result in the unnecessary expenditure of public resources or missing a human health problem. Historic lines of evidence for data collected prior to 2010 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. For E. coli data, Listing Policy sections 3.3 and 4.3 instructs to use the binomial distribution table in sections 3.2 and 4.2, as applicable. To use the binomial table that uses a four percent exceedance frequency, the data must be collected from coastal beaches or inland surface waters from April 1 through October 31 only, and where collected from inland waters from April 1 through October 31 only, bacterial measurements must be indicative of human fecal matter, and there is substantial human contact in the waterbody. No fecal coliform data are used in this assessment because the fecal coliform water quality objective was superseded and is no longer used as the basis of any 303(d) List decision for water contact recreation.

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:	The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies Therefore, this waterbody is being considered for placement on or removal from the CWA section 303(d) List under section 3.3 or 4.3 of the Listing Policy, as applicable, using the E. coli objective. In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Indicator bacteria (total coliform, fecal coliform, E. coli, enterococci) populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, they do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of indicator bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address bacteria. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the list, which could result in the unnecessary expenditure of public resources or missing a human health problem. Historic lines of evidence for data collected prior to 2010 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. For E. coli data, Listing Policy sections 3.3 and 4.3 instructs to use the binomial distribution table in sections 3.2 and 4.2, as applicable. To use the binomial table that uses a four percent exceedance frequency, the data must be collected from coastal beaches or inland surface waters from April 1 through October 31 only, and where collected from inland waters from April 1 through October 31 only, bacterial measurements must be indicative of human fecal matter, and there is substantial human contact in the waterbody. No fecal coliform data are used in this assessment because the fecal coliform water quality objective was superseded and is no longer used as the basis of any 303(d) List decision for water contact recreation.

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 128036, Indicator Bacteria	Region 9
Santa Margarita River (Lower)

LOE ID:

76464

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed County of San Diego data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Coliform, Fecal.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

In waters designated for water contact recreation (REC I), the fecal coliform concentration shall not exceed 400 MPN/100 ml.

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ Santa Margarita Estuary, Santa Margarita Estuary, Santa Margarita Estuary, Santa Margarita Estuary]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 128036, Indicator Bacteria	Region 9
Santa Margarita River (Lower)

LOE ID:

76465

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

In waters designated for non contact recreation (REC 2), the fecal coliform concentration shall not exceed 4000 MPN/100 ml (Basin Plan).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 128036, Indicator Bacteria	Region 9
Santa Margarita River (Lower)

LOE ID:

7503

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PWS pathogen monitoring (ambient water)

Data Used to Assess Water Quality:

All five samples collected exceed the water quality objective according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected one to two times a year from 2001 - 2006, with the exception of the 2004-2005 monitoring year.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

From the Basin Plan, the bacteriological criteria for enterococcus sets a maximum limit at 61 colonies per 100mL (RWQCB, 2007).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.

Temporal Representation:

Samples were collected one to two times a year from 2001 - 2006, with the exception of the 2004-2005 monitoring year.

Environmental Conditions:

Samples were collected during wet weather.

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 128036, Indicator Bacteria	Region 9
Santa Margarita River (Lower)

LOE ID:

7504

Pollutant:

Fecal Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PWS pathogen monitoring (ambient water)

Data Used to Assess Water Quality:

All five samples collected exceed the water quality objective according to resuls in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected one to two times a year from 2001 - 2006, with the exception of the 2004-2005 monitoring year.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No more than 10% of the samples during any 30-day period for waters designated for contact recreation shall exceed 400 colonies per 100 ml (RWQCB, 2007).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.

Temporal Representation:

Samples were collected one to two times a year from 2001 - 2006, with the exception of the 2004-2005 monitoring year.

Environmental Conditions:

Samples were collected during wet weather.

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 128036, Indicator Bacteria	Region 9
Santa Margarita River (Lower)

LOE ID:

76542

Pollutant:

Total Coliform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxicsubstances in concentrations which are toxic to,or which produce detrimental physiologicalresponses in human, plant, animal, or indigenousaquatic life (Basin Plan).

Objective/Criterion Reference:

Draft Guidance for Fresh Water Beaches. Last Update: May 8, 2006. Initial Draft: November 1997. California Department of Public Health.

Evaluation Guideline:

In waters designated for water contact recreation (REC I), the total coliform concentration shall not exceed 10000 MPN/100 ml (CDPH 2006).

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 128036, Indicator Bacteria	Region 9
Santa Margarita River (Lower)

LOE ID:

76463

Pollutant:

Enterococcus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Samples shall not exceed 61 organisms per 100 ml for enterococcus in waters designated for REC I beneficial use (Water Quality Control Plan for the San Diego Basin).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):


DECISION ID	127616	Region 9
Santa Margarita River (Lower)

Pollutant:	Nitrogen
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
Expected TMDL Completion Date:	2025
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. Four lines of evidence are available in the administrative record to assess pollutant. Twenty of the 24 samples exceed the water quality 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. Twenty of the 24 samples exceed the water quality 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:	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 127616, Nitrogen	Region 9
Santa Margarita River (Lower)

LOE ID:

144039

Pollutant:

Total Nitrogen as N

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 127616, Nitrogen	Region 9
Santa Margarita River (Lower)

LOE ID:

143980

Pollutant:

Total Nitrogen as N

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 127616, Nitrogen	Region 9
Santa Margarita River (Lower)

LOE ID:

7497

Pollutant:

Total Nitrogen as N

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 monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.

Temporal Representation:

Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.

Environmental Conditions:

Samples were collected during wet weather.

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 127616, Nitrogen	Region 9
Santa Margarita River (Lower)

LOE ID:

7498

Pollutant:

Total Nitrogen as N

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 monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA

Spatial Representation:

Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.

Temporal Representation:

Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.

Environmental Conditions:

Samples were collected during wet weather.

QAPP Information:

QA/QC conducted according to Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):


DECISION ID	111255	Region 9
Santa Margarita River (Lower)

Pollutant:	Phosphorus
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
Expected TMDL Completion Date:	2021
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. Four lines of evidence are available in the administrative record to assess pollutant. Twenty of the 22 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. Twenty of the 22 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:	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 111255, Phosphorus	Region 9
Santa Margarita River (Lower)

LOE ID:

7500

Pollutant:

Phosphorus

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 monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water bodies shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses.
Water Quality Control Plan for the San Diego Basin has a goal of 0.1 mg/L for total phosphorus in streams and other flowing waters. (RWQCB, 2007)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

Spatial Representation:

The sampling site lies on the lower Santa Margarita River (Santa Margarita 10 (902SSMR10 lat/long: 33.23669/-117.39175)).

Temporal Representation:

Samples were collected on the following dates: January 14, April 15, twice on May 13, and September 9, 2003.

Environmental Conditions:

The first two sampling events occurred between storm events and high base flow respectively. The third and fourth occurred during declining and minimum base flow respectively.

QAPP Information:

Quality control for the chemical analysis portion of this study was conducted in accordance with the California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111255, Phosphorus	Region 9
Santa Margarita River (Lower)

LOE ID:

145624

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111255, Phosphorus	Region 9
Santa Margarita River (Lower)

LOE ID:

146035

Pollutant:

Phosphorus

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111255, Phosphorus	Region 9
Santa Margarita River (Lower)

LOE ID:

7499

Pollutant:

Phosphorus

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 monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Five of six samples exceed the water quality objective according to results in the San Diego County Municipal Copermittees Annual Progress Report, 2007. Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the San Diego Basin has a goal of 0.1 mg/L for total phosphorus in streams and other flowing waters. (RWQCB, 2007)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

Spatial Representation:

Samples were collected at the mass loading station located near the lower boundary of the watershed on Camp Pendleton under the Basilone Road Bridge.

Temporal Representation:

Samples were collected one to two times a year from 2001-2006, with the exception of the 2004-2005 monitoring year.

Environmental Conditions:

Samples were collected during wet weather.

QAPP Information:

QA/QC conducted according to Federal Regulations under requirements of a NPDES permit.

QAPP Information Reference(s):


DECISION ID	111259	Region 9
Santa Margarita River (Lower)

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
Expected TMDL Completion Date:	2025
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 4.6 of the Listing Policy. Under this section, a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess pollutant. Seven of the 23 water samples exceed the water quality threshold. There are an insufficient number of sediment samples. 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. Seven of 23 samples exceeded the water quality 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:	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 111259, Toxicity	Region 9
Santa Margarita River (Lower)

LOE ID:

134750

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 9 samples collected by San Diego Region NPDES for Santa Margarita River (Lower) 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: Selenastrum capricornutum, for Total Cell Count, Ceriodaphnia dubia, for Survival, Selenastrum capricornutum, for Growth (Chlorophyll a), Strongylocentrotus purpuratus, for Normal Development, Pimephales promelas, for Survival, Pimephales promelas, for Biomass (wt/orig indiv), Ceriodaphnia dubia, for Reproduction

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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board.

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 station. Monitoring site: ( SLR-MLS )

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111259, Toxicity	Region 9
Santa Margarita River (Lower)

LOE ID:

7501

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Ambient toxicity testing (chronic)

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

From the Basin Plan, all waters shall be free of toxic substances that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (RWQCB, 2007).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA

Spatial Representation:

Samples were collected at the monitoring station Santa Margarita 10 located on the main stem of the Lower Santa Margarita River.

Temporal Representation:

Samples were collected on the following dates: January 14, April 15, May 13, and September 9, 2003.

Environmental Conditions:

QAPP Information:

Quality control for the chemical analysis portion of this study conducted in accordance with the California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111259, Toxicity	Region 9
Santa Margarita River (Lower)

LOE ID:

76544

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Copermittees Receiving Waters Monitoring and Reporting Program, 2001-2008.

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

Objective/Criterion Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. EPA-821-R-02-012

Evaluation Guideline:

Guideline Reference:

Guideline Reference:

Spatial Representation:

The samples were collected at station 902SMR-MLS - Santa Margarita River.

Temporal Representation:

The samples were collected from 2001 to 2008.

Environmental Conditions:

QAPP Information:

The data was collected under the County of San Diego Co-Permittees Receiving Waters Urban Runoff Monitoring and Reporting Program (Order No. 2007-01). Data quality is good.

QAPP Information Reference(s):

e-mail clarifying QAPP information

Line of Evidence (LOE) for Decision ID 111259, Toxicity	Region 9
Santa Margarita River (Lower)

LOE ID:

30287

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Ambient toxicity testing (chronic)

Data Used to Assess Water Quality:

Hyalella azteca-
Two samples were collected and neither shows significant toxicity levels (SL) as determined by the Hyalella azteca growth/survival test according to results in the Surface Water Ambient Monitoring Program Report, 2007. Samples were collected on the following dates: January 14, April 15, May 13, and September 9, 2003.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

From the Basin Plan, all waters shall be free of toxic substances that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (RWQCB, 2007).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA

Spatial Representation:

Samples were collected at the monitoring station Santa Margarita 10 located on the main stem of the Lower Santa Margarita River.

Temporal Representation:

Samples were collected on the following dates: January 14, April 15, May 13, and September 9, 2003.

Environmental Conditions:

QAPP Information:

Quality control for the chemical analysis portion of this study conducted in accordance with the California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111259, Toxicity	Region 9
Santa Margarita River (Lower)

LOE ID:

134781

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 station. Monitoring site: ( SLR-MLS )

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111259, Toxicity	Region 9
Santa Margarita River (Lower)

LOE ID:

76546

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One sample was collected to evaluate sediment toxicity. The sample did not exhibit significant toxicity. The toxicity test included survival of Hyalella azteca. One sample can have multiple toxicity test results but will be counted only once. One sample is defined as being collected on the same day at the same location with the same lab sample id (if provided).

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. Region 9 Basin Plan.

Objective/Criterion Reference:

SWAMP_Memo_Toxicity_Data_Intrepretation

Evaluation Guideline:

Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. For SWAMP data exceedances are counted with the significant effect code SL, Significant compared to negative control based on statistical test, less than stated alpha level, AND less than the evaluation threshold (both criteria are met).

Guideline Reference:

Spatial Representation:

The sample was collected at station 902SSMR07.

Temporal Representation:

The samples were collected in May 2008.

Environmental Conditions:

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission.

QAPP Information Reference(s):


DECISION ID	111270	Region 9
Santa Margarita River (Lower)

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:	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 111270, Alkalinity as CaCO3	Region 9
Santa Margarita River (Lower)

LOE ID:

139573

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Alkalinity as CaCO3.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

The CCC of 20mg/L is a minimum value except where alkalinity is naturally lower, in which case the criterion cannot be lower than 25% of the natural level (USEPA National Recommended Water Quality Criteria Aquatic Life)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-06-01 and 2017-06-01

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111270, Alkalinity as CaCO3	Region 9
Santa Margarita River (Lower)

LOE ID:

139591

Pollutant:

Alkalinity as CaCO3

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-06-01 and 2017-06-01

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	127800	Region 9
Santa Margarita River (Lower)

Pollutant:	Ammonia
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 127800, Ammonia	Region 9
Santa Margarita River (Lower)

LOE ID:

184937

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) 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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-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 Ammonia - Freshwater 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 (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2013-02-09 and 2017-01-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 127800, Ammonia	Region 9
Santa Margarita River (Lower)

LOE ID:

184951

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:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-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 (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2013-02-09 and 2017-01-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	115483	Region 9
Santa Margarita River (Lower)

Pollutant:	Ammonia (Unionized)
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 115483, Ammonia (Unionized)	Region 9
Santa Margarita River (Lower)

LOE ID:

185337

Pollutant:

Ammonia (Unionized)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Ammonia as N, Unionized. 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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The discharge of wastes shall not cause concentrations of un-ionized ammonia (NH3) to exceed 0.025 mg/l (as N) in inland surface waters, enclosed bays and estuaries and coastal lagoons (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-02-09 to 2017-01-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 115483, Ammonia (Unionized)	Region 9
Santa Margarita River (Lower)

LOE ID:

185398

Pollutant:

Ammonia (Unionized)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-02-09 to 2017-01-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111238	Region 9
Santa Margarita River (Lower)

Pollutant:	Antimony
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111238, Antimony	Region 9
Santa Margarita River (Lower)

LOE ID:

139848

Pollutant:

Antimony

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Antimony.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for antimony is .006 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2013-05-02

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111238, Antimony	Region 9
Santa Margarita River (Lower)

LOE ID:

139864

Pollutant:

Antimony

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2013-05-02

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111238, Antimony	Region 9
Santa Margarita River (Lower)

LOE ID:

78322

Pollutant:

Antimony

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Antimony.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278

Evaluation Guideline:

In marine and estuarine sediments the effects range median (predictive of sediment toxicity for sediment-dwelling organisms) for Antimony is 25 ug/g dry weight (Long and Morgan, 1990).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 111238, Antimony	Region 9
Santa Margarita River (Lower)

LOE ID:

77838

Pollutant:

Antimony

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed County of San Diego data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for Antimony.

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for antimony is .006 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):


DECISION ID	111239	Region 9
Santa Margarita River (Lower)

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 sections 3.1 and 3.6 of the Listing Policy. 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. Ten lines of evidence are available in the administrative record to assess this pollutant. Zero of 19 samples exceed the water quality threshold in water for the MUN beneficial use, zero of 20 samples exceed the water quality threshold in water for the WARM beneficial use, and zero of five samples exceed the water quality threshold in sediment. 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 19 samples exceed the water quality threshold in water for the MUN beneficial use, zero of 20 samples exceed the water quality threshold in water for the WARM beneficial use, and zero of five samples exceed the water quality threshold in sediment, and this sample size is sufficient to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111239, Arsenic	Region 9
Santa Margarita River (Lower)

LOE ID:

140047

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 14 samples exceeded the water quality threshold for Arsenic.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-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 0.150 mg/L (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 (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111239, Arsenic	Region 9
Santa Margarita River (Lower)

LOE ID:

139944

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-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 0.150 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111239, Arsenic	Region 9
Santa Margarita River (Lower)

LOE ID:

140184

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for arsenic is 0.01 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111239, Arsenic	Region 9
Santa Margarita River (Lower)

LOE ID:

140339

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-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 0.150 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111239, Arsenic	Region 9
Santa Margarita River (Lower)

LOE ID:

78323

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Arsenic.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97

Evaluation Guideline:

In marine and estuarine sediments the effects range median (predictive of sediment toxicity for sediment-dwelling organisms) for Arsenic is 70 ug/g dry weight (Long et al., 1995).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 111239, Arsenic	Region 9
Santa Margarita River (Lower)

LOE ID:

139868

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-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 0.150 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111239, Arsenic	Region 9
Santa Margarita River (Lower)

LOE ID:

77840

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-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 0.150 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111239, Arsenic	Region 9
Santa Margarita River (Lower)

LOE ID:

77841

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for arsenic is 0.01 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111239, Arsenic	Region 9
Santa Margarita River (Lower)

LOE ID:

76470

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Arsenic.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for arsenic is 33 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the 2002 QAMP.

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 111239, Arsenic	Region 9
Santa Margarita River (Lower)

LOE ID:

140003

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for arsenic is 0.01 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111264	Region 9
Santa Margarita River (Lower)

Pollutant:	Bifenthrin
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
Expected TMDL Completion Date:	2033
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111264, Bifenthrin	Region 9
Santa Margarita River (Lower)

LOE ID:

76472

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Bifenthrin.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

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:

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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	111240	Region 9
Santa Margarita River (Lower)

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 sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary, and 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. Nine lines of evidence for sediment and two lines of evidence for water are available in the administrative record to assess this pollutant. Zero of 20 samples exceed the water quality threshold in water for the COLD beneficial use, zero of 19 samples exceed the water quality threshold in water for the MUN beneficial use, and zero of five samples exceed the water quality threshold in sediment. 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 20 samples exceed the water quality threshold in water for the COLD beneficial use, zero of 19 samples exceed the water quality threshold in water for the MUN beneficial use, and these sample sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111240, Cadmium	Region 9
Santa Margarita River (Lower)

LOE ID:

140720

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-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 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111240, Cadmium	Region 9
Santa Margarita River (Lower)

LOE ID:

76474

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed County of San Diego NDPES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for Cadmium.

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations for dissolved Cadmium to protect aquatic life in freshwater. The dissolved Cadmium 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:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected 11/29/2001-02/28/2006.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Weston, the Regional Monitoring Workgroup Urban Runoff Monitoring Final Report Methods Sections and Statements of Work, and Weston Solutions Inc. Desk Reference for Quality Control Of Work Products was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111240, Cadmium	Region 9
Santa Margarita River (Lower)

LOE ID:

77844

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111240, Cadmium	Region 9
Santa Margarita River (Lower)

LOE ID:

140467

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111240, Cadmium	Region 9
Santa Margarita River (Lower)

LOE ID:

140583

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for cadmium is 0.005 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111240, Cadmium	Region 9
Santa Margarita River (Lower)

LOE ID:

140635

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for cadmium is 0.005 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111240, Cadmium	Region 9
Santa Margarita River (Lower)

LOE ID:

78325

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Cadmium.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278

Evaluation Guideline:

In marine and estuarine sediments the probable effect level (predictive of sediment toxicity for sediment-dwelling organisms) for Cadmium is 4.21 ng/g dry weight (MacDonald et al., 1996).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 111240, Cadmium	Region 9
Santa Margarita River (Lower)

LOE ID:

76473

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Cadmium.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for cadmium is 4.98 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the 2002 QAMP.

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 111240, Cadmium	Region 9
Santa Margarita River (Lower)

LOE ID:

77845

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for cadmium is 0.005 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):


DECISION ID	111274	Region 9
Santa Margarita River (Lower)

Pollutant:	Chromium
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111274, Chromium	Region 9
Santa Margarita River (Lower)

LOE ID:

141403

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for total chromium is 0.05 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111274, Chromium	Region 9
Santa Margarita River (Lower)

LOE ID:

141166

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for total chromium is 0.05 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111274, Chromium	Region 9
Santa Margarita River (Lower)

LOE ID:

141100

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111274, Chromium	Region 9
Santa Margarita River (Lower)

LOE ID:

141152

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111274, Chromium	Region 9
Santa Margarita River (Lower)

LOE ID:

76477

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed County of San Diego NDPES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chromium.

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations for dissolved chromium to protect aquatic life in freshwater. The dissolved Chromium 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:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected on a single day 11/29/2001.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111274, Chromium	Region 9
Santa Margarita River (Lower)

LOE ID:

78328

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Chromium.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97

Evaluation Guideline:

In marine and estuarine sediments the effects range median (predictive of sediment toxicity for sediment-dwelling organisms) for Chromium is 370 ug/g dry weight (Long et al., 1995).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 111274, Chromium	Region 9
Santa Margarita River (Lower)

LOE ID:

76476

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chromium.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for chromium is 111 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the 2002 QAMP.

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	111242	Region 9
Santa Margarita River (Lower)

Pollutant:	Chromium, trivalent
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 111242, Chromium, trivalent	Region 9
Santa Margarita River (Lower)

LOE ID:

141532

Pollutant:

Chromium, trivalent

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-31 and 2017-03-30

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111242, Chromium, trivalent	Region 9
Santa Margarita River (Lower)

LOE ID:

141508

Pollutant:

Chromium, trivalent

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

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, San Diego Basin). The California Maximum Contaminant Level for total chromium, incorporated into the basin plan by reference, is 0.05 mg/L .

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-31 and 2017-03-30

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111242, Chromium, trivalent	Region 9
Santa Margarita River (Lower)

LOE ID:

141488

Pollutant:

Chromium, trivalent

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-31 and 2017-03-30

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111243	Region 9
Santa Margarita River (Lower)

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 sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary, and 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. Eight lines of evidence are available in the administrative record to assess this pollutant. Zero of five samples (sediment) and one of twenty samples (water) exceeded the water quality threshold for the WARM beneficial use. Zero of 19 samples exceed the water quality threshold for the MUN beneficial use. 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 20 samples exceed the water quality threshold for the WARM beneficial use, zero of 19 samples exceed the water quality threshold for the MUN beneficial use, and this sample size is sufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111243, Copper	Region 9
Santa Margarita River (Lower)

LOE ID:

77853

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL for copper is 1.0 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111243, Copper	Region 9
Santa Margarita River (Lower)

LOE ID:

78333

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Copper.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97

Evaluation Guideline:

In marine and estuarine sediments the effects range median (predictive of sediment toxicity for sediment-dwelling organisms) for Copper is 270 ug/g dry weight (Long et al., 1995).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 111243, Copper	Region 9
Santa Margarita River (Lower)

LOE ID:

76478

Pollutant:

Copper

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Copper.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for copper is 149 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the 2002 QAMP.

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 111243, Copper	Region 9
Santa Margarita River (Lower)

LOE ID:

77852

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:

State Water Board staff assessed County of San Diego data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 1 of 6 samples exceed the criterion for Copper.

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations for dissolved Copper to protect aquatic life in freshwater. The dissolved Copper 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:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111243, Copper	Region 9
Santa Margarita River (Lower)

LOE ID:

141673

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL for copper is 1.0 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111243, Copper	Region 9
Santa Margarita River (Lower)

LOE ID:

141652

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL for copper is 1.0 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111243, Copper	Region 9
Santa Margarita River (Lower)

LOE ID:

141517

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111243, Copper	Region 9
Santa Margarita River (Lower)

LOE ID:

141633

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111271	Region 9
Santa Margarita River (Lower)

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:	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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111271, Cyfluthrin	Region 9
Santa Margarita River (Lower)

LOE ID:

77855

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Cyfluthrin, total.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

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 from Amweg et al. (2005).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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	111273	Region 9
Santa Margarita River (Lower)

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:	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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111273, Cyhalothrin, Lambda	Region 9
Santa Margarita River (Lower)

LOE ID:

143105

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Lambda-cyhalothrin.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Evaluation Guideline:

The chronic concentration goal 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:

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 (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-05-09 and 2017-05-09

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111273, Cyhalothrin, Lambda	Region 9
Santa Margarita River (Lower)

LOE ID:

143086

Pollutant:

Cyhalothrin, Lambda

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Evaluation Guideline:

Guideline Reference:

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 (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-05-09 and 2017-05-09

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111273, Cyhalothrin, Lambda	Region 9
Santa Margarita River (Lower)

LOE ID:

143040

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 San Diego Region NPDES data for Santa Margarita River (Lower) 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 8 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Evaluation Guideline:

Guideline Reference:

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 (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-02-18 to 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111273, Cyhalothrin, Lambda	Region 9
Santa Margarita River (Lower)

LOE ID:

136644

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 San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and the results are as follows: 0 of the 2 samples exceeded the evaluation guideline for Cyhalothrin, Total lambda- .

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

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 from Amweg et al. (2005).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-10-27 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111273, Cyhalothrin, Lambda	Region 9
Santa Margarita River (Lower)

LOE ID:

77856

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Cyhalothrin, lambda, total.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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 111273, Cyhalothrin, Lambda	Region 9
Santa Margarita River (Lower)

LOE ID:

136643

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-10-27 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111273, Cyhalothrin, Lambda	Region 9
Santa Margarita River (Lower)

LOE ID:

142927

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) 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 8 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Evaluation Guideline:

Guideline Reference:

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 (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-02-18 to 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111265	Region 9
Santa Margarita River (Lower)

Pollutant:	Cypermethrin
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111265, Cypermethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

142040

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal 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:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-05-09 and 2017-05-09

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111265, Cypermethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

136729

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

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:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-10-27 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111265, Cypermethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

136782

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-10-27 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111265, Cypermethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

142209

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) 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 8 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-02-18 to 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111265, Cypermethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

142089

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 San Diego Region NPDES data for Santa Margarita River (Lower) 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 8 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-02-18 to 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111265, Cypermethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

141813

Pollutant:

Cypermethrin

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-05-09 and 2017-05-09

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111265, Cypermethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

77857

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Cypermethrin, total.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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	111272	Region 9
Santa Margarita River (Lower)

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:	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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111272, Deltamethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

136860

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

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 from Amweg et al. (2005).

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-10-27 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111272, Deltamethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

136910

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-10-27 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111272, Deltamethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

142297

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 9 samples exceeded the water quality threshold for Deltamethrin.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Deltamethrin is the USEPA Aquatic Life Benchmark of 0.0041 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-02-18 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111272, Deltamethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

142249

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:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Deltamethrin is the USEPA Aquatic Life Benchmark of 0.0041 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-02-18 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111272, Deltamethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

77858

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Deltamethrin.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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	111276	Region 9
Santa Margarita River (Lower)

Pollutant:	Demeton
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 111276, Demeton	Region 9
Santa Margarita River (Lower)

LOE ID:

142183

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

The USEPA National Recomm. Water Quality criteria, 4-day avg. is 0.1 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111276, Demeton	Region 9
Santa Margarita River (Lower)

LOE ID:

142201

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

The USEPA National Recomm. Water Quality criteria, 4-day avg. is 0.1 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111244	Region 9
Santa Margarita River (Lower)

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 sections 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 additional lines of evidence are necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the 16 samples exceed the water quality threshold in water. Zero of one sample exceeds the water quality threshold in sediment, but this sample size is insufficient to determine beneficial use support with the statistical power and confidence of the Listing Policy. 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 16 samples exceeded the water quality threshold, 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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111244, Diazinon	Region 9
Santa Margarita River (Lower)

LOE ID:

142136

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

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:

2018 Edition of the Drinking Water Standards and Health Advisories

Evaluation Guideline:

The USEPA drinking water health advisory for diazinon is 1.4 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111244, Diazinon	Region 9
Santa Margarita River (Lower)

LOE ID:

142151

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

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 for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111244, Diazinon	Region 9
Santa Margarita River (Lower)

LOE ID:

142134

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111244, Diazinon	Region 9
Santa Margarita River (Lower)

LOE ID:

77831

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Diazinon.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Evaluation Guideline:

The evaluation guideline for diazinon is the median lethal concentration (LC50) of 11 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 11 ug/g is the geometric mean of LC50 values for diazinon from Ding et al. (2011).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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 111244, Diazinon	Region 9
Santa Margarita River (Lower)

LOE ID:

77834

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

State Water Board staff assessed County of San Diego data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Diazinon. Three of the six samples could not be used in this assessment because they lacked sufficiently sensitive methods.

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

2011 Edition of the Drinking Water Standards and Health Advisories

Evaluation Guideline:

The California Department of Public Health (CDPH) Notification Level for Diazinon is 1.2 ug/L.

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111244, Diazinon	Region 9
Santa Margarita River (Lower)

LOE ID:

77832

Pollutant:

Diazinon

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:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):


DECISION ID	111245	Region 9
Santa Margarita River (Lower)

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 111245, Dichlorvos	Region 9
Santa Margarita River (Lower)

LOE ID:

142052

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) 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 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-12 to 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111245, Dichlorvos	Region 9
Santa Margarita River (Lower)

LOE ID:

142458

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) 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 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-01-12 to 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111266	Region 9
Santa Margarita River (Lower)

Pollutant:	Dimethoate
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 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 111266, Dimethoate	Region 9
Santa Margarita River (Lower)

LOE ID:

142385

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111266, Dimethoate	Region 9
Santa Margarita River (Lower)

LOE ID:

142488

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

CDPH Archived Advisory Levels for Drinking Water. Archived Advisory Levels are currently considered Notification Levels.

Evaluation Guideline:

The California Department of Health Services notification level for dimethoate is 1 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111266, Dimethoate	Region 9
Santa Margarita River (Lower)

LOE ID:

142531

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111246	Region 9
Santa Margarita River (Lower)

Pollutant:	Disulfoton
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 111246, Disulfoton	Region 9
Santa Margarita River (Lower)

LOE ID:

142507

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 11 samples exceeded the water quality threshold for Disulfoton.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

2018 Edition of the Drinking Water Standards and Health Advisories

Evaluation Guideline:

The USEPA drinking water health advisory for disulfoton is 0.7 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-09

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111277	Region 9
Santa Margarita River (Lower)

Pollutant:	Esfenvalerate/Fenvalerate
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111277, Esfenvalerate/Fenvalerate	Region 9
Santa Margarita River (Lower)

LOE ID:

142466

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) 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 8 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal 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:

Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Pyrethroid Pesticide Discharges

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-02-18 to 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111277, Esfenvalerate/Fenvalerate	Region 9
Santa Margarita River (Lower)

LOE ID:

77835

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Esfenvalerate/Fenvalerate, total.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

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 from Amweg et al. (2005).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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 111277, Esfenvalerate/Fenvalerate	Region 9
Santa Margarita River (Lower)

LOE ID:

142561

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-05-09 and 2017-05-09

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111277, Esfenvalerate/Fenvalerate	Region 9
Santa Margarita River (Lower)

LOE ID:

142510

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 San Diego Region NPDES data for Santa Margarita River (Lower) 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 8 samples were collected, 8 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-02-18 to 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111277, Esfenvalerate/Fenvalerate	Region 9
Santa Margarita River (Lower)

LOE ID:

142453

Pollutant:

Esfenvalerate/Fenvalerate

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-05-09 and 2017-05-09

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111277, Esfenvalerate/Fenvalerate	Region 9
Santa Margarita River (Lower)

LOE ID:

137533

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-10-27 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111277, Esfenvalerate/Fenvalerate	Region 9
Santa Margarita River (Lower)

LOE ID:

137479

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-10-27 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111267	Region 9
Santa Margarita River (Lower)

Pollutant:	Ethoprop
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 111267, Ethoprop	Region 9
Santa Margarita River (Lower)

LOE ID:

142671

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111267, Ethoprop	Region 9
Santa Margarita River (Lower)

LOE ID:

142363

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111275	Region 9
Santa Margarita River (Lower)

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:	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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111275, Fenpropathrin	Region 9
Santa Margarita River (Lower)

LOE ID:

77836

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Fenpropathrin.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

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:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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 111275, Fenpropathrin	Region 9
Santa Margarita River (Lower)

LOE ID:

137394

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Fenpropathrin .

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2013-02-15 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111275, Fenpropathrin	Region 9
Santa Margarita River (Lower)

LOE ID:

142657

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.06 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-02-18 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111275, Fenpropathrin	Region 9
Santa Margarita River (Lower)

LOE ID:

142617

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.06 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-02-18 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111275, Fenpropathrin	Region 9
Santa Margarita River (Lower)

LOE ID:

137341

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2013-02-15 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111237	Region 9
Santa Margarita River (Lower)

Pollutant:	Fenvalerate
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 111237, Fenvalerate	Region 9
Santa Margarita River (Lower)

LOE ID:

142783

Pollutant:

Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

OPP Pesticide Ecotoxicity Database.

Evaluation Guideline:

The evaluation guideline for Fenvalerate is the LC50 of 1.13 ug/L for fathead minnow, Pimephales promelas. (USEPA Office of Pesticide Programs Ecotoxicity database)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-02-18 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111237, Fenvalerate	Region 9
Santa Margarita River (Lower)

LOE ID:

142801

Pollutant:

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

OPP Pesticide Ecotoxicity Database.

Evaluation Guideline:

The evaluation guideline for Fenvalerate is the LC50 of 1.13 ug/L for fathead minnow, Pimephales promelas. (USEPA Office of Pesticide Programs Ecotoxicity database)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-02-18 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111248	Region 9
Santa Margarita River (Lower)

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:	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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111248, Lead	Region 9
Santa Margarita River (Lower)

LOE ID:

76466

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations for dissolved lead to protect aquatic life in freshwater. The dissolved lead 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:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected on a single day 11/29/2001.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111248, Lead	Region 9
Santa Margarita River (Lower)

LOE ID:

78314

Pollutant:

Lead

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Lead.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278

Evaluation Guideline:

In marine and estuarine sediments the probable effect level (predictive of sediment toxicity for sediment-dwelling organisms) for Lead is 112.18 ug/g dry weight (MacDonald et al., 1996).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 111248, Lead	Region 9
Santa Margarita River (Lower)

LOE ID:

142895

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111248, Lead	Region 9
Santa Margarita River (Lower)

LOE ID:

143112

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for lead is .015 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111248, Lead	Region 9
Santa Margarita River (Lower)

LOE ID:

143019

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Maximum Contaminant Level for lead is .015 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111248, Lead	Region 9
Santa Margarita River (Lower)

LOE ID:

142931

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	128183	Region 9
Santa Margarita River (Lower)

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:	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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 128183, Mercury	Region 9
Santa Margarita River (Lower)

LOE ID:

78318

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Mercury.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Pollutants of concern in Puget Sound. EPA 910/9-91-003. Seattle, WA: U.S. Environmental Protection Agency

Evaluation Guideline:

In marine and estuarine sediments the sediment quality guideline (predictive of sediment toxicity for sediment-dwelling organisms) for Mercury is 2.1 ug/g (PTI Environmental Services, 1991).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 128183, Mercury	Region 9
Santa Margarita River (Lower)

LOE ID:

76467

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Mercury.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for mercury is 1.06 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the 2002 QAMP.

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 128183, Mercury	Region 9
Santa Margarita River (Lower)

LOE ID:

3012

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Total

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

None of 4 samples for mercury in fish tissue taken exceeded the screening value. (TSMP, 2002).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

OEHHA screening value for mercury 0.3 mg/kg (ppm).

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Lower Santa Margarita River.

Temporal Representation:

Samples were taken between March 1979 and August 1999.

Environmental Conditions:

QAPP Information:

CFCP 1998 Year 1 QA Summary Pesticides and PCBs. California Department of Fish and Game.

CDFG Fish and Wildlife Water Pollution Control Laboratory Data Quality
Assurance Report. 1999 Coastal Fish Contamination Program (CFCP Year 2). California Department of Fish and Game.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 128183, Mercury	Region 9
Santa Margarita River (Lower)

LOE ID:

143415

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Mercury.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The mercury criteria for the protection of human health from the consumption of water and organisms for mercury is 0.050 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-31 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 128183, Mercury	Region 9
Santa Margarita River (Lower)

LOE ID:

143126

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The mercury criteria for the protection of human health from the consumption of water and organisms for mercury is 0.050 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-31 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111269	Region 9
Santa Margarita River (Lower)

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:

Line of Evidence (LOE) for Decision ID 111269, Naled	Region 9
Santa Margarita River (Lower)

LOE ID:

143326

Pollutant:

Naled

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Naled is the USEPA Aquatic Life Benchmark of 0.045 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-09

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111269, Naled	Region 9
Santa Margarita River (Lower)

LOE ID:

143344

Pollutant:

Naled

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Naled is the USEPA Aquatic Life Benchmark of 0.045 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-09

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111251	Region 9
Santa Margarita River (Lower)

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 sections 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary, and under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. Five lines of evidence are available in the administrative record to assess this pollutant. Zero of the 20 samples exceed the water quality threshold for the COLD beneficial use. Zero of the 19 samples exceed the water quality threshold for the MUN beneficial use. Zero of one sediment sample exceeds the water quality threshold for sediment; this sample size is not sufficient to determine beneficial use support with the power and confidence of the Listing Policy. 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 20 samples exceed the threshold for the COLD beneficial use, and zero of 19 samples exceed the threshold for the MUN beneficial use, 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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111251, Nickel	Region 9
Santa Margarita River (Lower)

LOE ID:

77862

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations for dissolved Nickel to protect aquatic life in freshwater. The dissolved Nickel 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:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111251, Nickel	Region 9
Santa Margarita River (Lower)

LOE ID:

143627

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111251, Nickel	Region 9
Santa Margarita River (Lower)

LOE ID:

143672

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111251, Nickel	Region 9
Santa Margarita River (Lower)

LOE ID:

76622

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Nickel.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for nickel is 48.6 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the 2002 QAMP.

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 111251, Nickel	Region 9
Santa Margarita River (Lower)

LOE ID:

77865

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111251, Nickel	Region 9
Santa Margarita River (Lower)

LOE ID:

77863

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nickel is 0.1 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111251, Nickel	Region 9
Santa Margarita River (Lower)

LOE ID:

143757

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nickel is 0.1 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111251, Nickel	Region 9
Santa Margarita River (Lower)

LOE ID:

143734

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nickel is 0.1 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	128272	Region 9
Santa Margarita River (Lower)

Pollutant:	Nitrogen, Nitrite
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. Zero of the 18 samples exceed the water quality threshold. 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 18 samples exceed the water quality threshold 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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 128272, Nitrogen, Nitrite	Region 9
Santa Margarita River (Lower)

LOE ID:

77868

Pollutant:

Nitrogen, Nitrite

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrite (as N) is 1.0 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 128272, Nitrogen, Nitrite	Region 9
Santa Margarita River (Lower)

LOE ID:

144012

Pollutant:

Nitrogen, Nitrite

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrite (as N) is 1.0 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Title 22. Division 4. Chapter 15. Sections 64400 et seq. California Code of Regulations

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111252	Region 9
Santa Margarita River (Lower)

Pollutant:	Oxygen, Dissolved
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 111252, Oxygen, Dissolved	Region 9
Santa Margarita River (Lower)

LOE ID:

144725

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:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Dissolved oxygen levels shall not be less than 5.0 mg/l in inland surface waters with the WARM beneficial use designated (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-20 and 2017-06-01

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111252, Oxygen, Dissolved	Region 9
Santa Margarita River (Lower)

LOE ID:

144404

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Dissolved oxygen levels shall not be less than 6.0 mg/l in inland surface waters with the COLD beneficial use designated (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-20 and 2017-06-01

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111253	Region 9
Santa Margarita River (Lower)

Pollutant:	Parathion
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 111253, Parathion	Region 9
Santa Margarita River (Lower)

LOE ID:

144840

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

The USEPA recommended freshwater aquatic life ambient water quality chronic criteria for Parathion is 0.013 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111253, Parathion	Region 9
Santa Margarita River (Lower)

LOE ID:

145023

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:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

The USEPA recommended freshwater aquatic life ambient water quality chronic criteria for Parathion is 0.013 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	130320	Region 9
Santa Margarita River (Lower)

Pollutant:	Permethrin
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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 130320, Permethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

76524

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Permethrin, Total.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

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 from Amweg et al. (2005).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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 130320, Permethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

144774

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 San Diego Region NPDES data for Santa Margarita River (Lower) 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 9 samples were collected, 9 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Criteria Report for Permethrin

Evaluation Guideline:

The chronic concentration goal 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:

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 (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-02-18 to 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 130320, Permethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

138645

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-10-27 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 130320, Permethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

144794

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) 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 9 samples were collected, 9 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Criteria Report for Permethrin

Evaluation Guideline:

Guideline Reference:

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 (SLR-MLS).

Temporal Representation:

Date for this waterbody was collected over the date range 2011-02-18 to 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 130320, Permethrin	Region 9
Santa Margarita River (Lower)

LOE ID:

138596

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion 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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): SLR-MLS.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-10-27 to 2013-02-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111268	Region 9
Santa Margarita River (Lower)

Pollutant:	Phorate
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 111268, Phorate	Region 9
Santa Margarita River (Lower)

LOE ID:

145545

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

National Academy of Sciences - Volume I Drinking Water and Health

Evaluation Guideline:

The national academy of sciences no-adverse effect level in drinking water for phorate is 0.7 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111268, Phorate	Region 9
Santa Margarita River (Lower)

LOE ID:

145795

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111268, Phorate	Region 9
Santa Margarita River (Lower)

LOE ID:

145597

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan from Southern California Bight.

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2011-01-12 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111256	Region 9
Santa Margarita River (Lower)

Pollutant:	Selenium
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. Zero of the 20 samples exceed the water quality threshold. 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 20 samples exceeded the threshold, 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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111256, Selenium	Region 9
Santa Margarita River (Lower)

LOE ID:

77875

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:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

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 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111256, Selenium	Region 9
Santa Margarita River (Lower)

LOE ID:

77876

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Maximum Contaminant Level for selenium in the Basin Plan is 0.05 mg/L (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111256, Selenium	Region 9
Santa Margarita River (Lower)

LOE ID:

77878

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater 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:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111256, Selenium	Region 9
Santa Margarita River (Lower)

LOE ID:

146102

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

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 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111256, Selenium	Region 9
Santa Margarita River (Lower)

LOE ID:

146402

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California MCL for Selenium is .05 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111256, Selenium	Region 9
Santa Margarita River (Lower)

LOE ID:

146342

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

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 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111256, Selenium	Region 9
Santa Margarita River (Lower)

LOE ID:

146450

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

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 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111256, Selenium	Region 9
Santa Margarita River (Lower)

LOE ID:

146451

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:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

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 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111256, Selenium	Region 9
Santa Margarita River (Lower)

LOE ID:

146202

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California MCL for Selenium is .05 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111257	Region 9
Santa Margarita River (Lower)

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:	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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111257, Silver	Region 9
Santa Margarita River (Lower)

LOE ID:

146382

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Silver.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-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:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-31 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111257, Silver	Region 9
Santa Margarita River (Lower)

LOE ID:

146907

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Table 64449-A of section 64449 of Title 22 of the California Code of Regulations (Secondary Maximum Contaminant Levels, Consumer Acceptance Limits) which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Secondary MCL for silver is 0.1 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-31 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111257, Silver	Region 9
Santa Margarita River (Lower)

LOE ID:

146359

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Table 64449-A of section 64449 of Title 22 of the California Code of Regulations (Secondary Maximum Contaminant Levels, Consumer Acceptance Limits) which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Secondary MCL for silver is 0.1 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-31 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111257, Silver	Region 9
Santa Margarita River (Lower)

LOE ID:

78347

Pollutant:

Silver

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Silver.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278

Evaluation Guideline:

In marine and estuarine sediments the probable effect level (predictive of sediment toxicity for sediment-dwelling organisms) for Silver is 1.77 ug/g dry weight (MacDonald et al., 1996).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 111257, Silver	Region 9
Santa Margarita River (Lower)

LOE ID:

146852

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-31 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	127654	Region 9
Santa Margarita River (Lower)

Pollutant:	Specific Conductivity
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. One line of evidence is available in the administrative record to assess this pollutant. Ten of the 13 samples exceed the California Secondary MCL for Specific Conductivity. However, this is a recommended, not required value, which is lower than the upper and short-term acceptable ranges in Table 64449-B and is lower than the naturally occurring specific conductance in some southern California streams. This water quality threshold will be reevaluated for future Integrated Report cycles.

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 127654, Specific Conductivity	Region 9
Santa Margarita River (Lower)

LOE ID:

146953

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 10 of 13 samples exceeded the water quality threshold for SpecificConductivity.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Table 64449-A of section 64449 of Title 22 of the California Code of Regulations (Secondary Maximum Contaminant Levels, Consumer Acceptance Limits) which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Secondary MCL for specific conductance is 900 uS/cm (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-19 and 2017-06-01

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111262	Region 9
Santa Margarita River (Lower)

Pollutant:	Surfactants (MBAS)
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 111262, Surfactants (MBAS)	Region 9
Santa Margarita River (Lower)

LOE ID:

143359

Pollutant:

Surfactants (MBAS)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Secondary California Maximum Contaminant Level for MBAS is 0.5 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111258	Region 9
Santa Margarita River (Lower)

Pollutant:	Thallium
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 111258, Thallium	Region 9
Santa Margarita River (Lower)

LOE ID:

147247

Pollutant:

Thallium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Thallium.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The thallium criterion for the protection of human health from the consumption of water and organisms is 1.7 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111258, Thallium	Region 9
Santa Margarita River (Lower)

LOE ID:

147271

Pollutant:

Thallium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The thallium criterion for the protection of human health from the consumption of water and organisms is 1.7 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2017-01-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	111261	Region 9
Santa Margarita River (Lower)

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:	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 this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 111261, Zinc	Region 9
Santa Margarita River (Lower)

LOE ID:

76563

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations for dissolved Zinc to protect aquatic life in freshwater. The dissolved Zinc 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:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected on a single day 11/29/2001.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111261, Zinc	Region 9
Santa Margarita River (Lower)

LOE ID:

78348

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Zinc.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97

Evaluation Guideline:

In marine and estuarine sediments the effects range median (predictive of sediment toxicity for sediment-dwelling organisms) for Zinc is 410 ug/g dry weight (Long et al., 1995).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 111261, Zinc	Region 9
Santa Margarita River (Lower)

LOE ID:

76556

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Zinc.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity for sediment-dwelling organisms) for Zinc is 459 mg/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the 2002 QAMP.

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 111261, Zinc	Region 9
Santa Margarita River (Lower)

LOE ID:

77882

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

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 physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, San Diego Basin).

Objective/Criterion Reference:

Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.

Evaluation Guideline:

The California Secondary MCL for zinc is 5.0 mg/L (Title 22 California Code of Regulations).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 111261, Zinc	Region 9
Santa Margarita River (Lower)

LOE ID:

147946

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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111261, Zinc	Region 9
Santa Margarita River (Lower)

LOE ID:

147809

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111261, Zinc	Region 9
Santa Margarita River (Lower)

LOE ID:

148191

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Secondary MCL for zinc is 5.0 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111261, Zinc	Region 9
Santa Margarita River (Lower)

LOE ID:

148136

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the maximum contaminant levels specified in Title 22 of the California Code of Regulations which is incorporated by reference into this plan. (Water Quality Control Plan, San Diego Basin). The California Secondary MCL for zinc is 5.0 mg/L (Title 22 California Code of Regulations).

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-20 and 2017-05-31

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111261, Zinc	Region 9
Santa Margarita River (Lower)

LOE ID:

77883

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):


DECISION ID	111254	Region 9
Santa Margarita River (Lower)

Pollutant:	pH
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 111254, pH	Region 9
Santa Margarita River (Lower)

LOE ID:

145465

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:

Water Board staff assessed San Diego Region NPDES data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 1 of 13 samples exceeded the water quality threshold for pH.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

In inland surface waters the pH shall not be depressed below 6.5 nor raised above 8.5.

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-19 and 2017-06-01

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load

Line of Evidence (LOE) for Decision ID 111254, pH	Region 9
Santa Margarita River (Lower)

LOE ID:

145349

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold 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, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 9.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

In inland surface waters the pH shall not be depressed below 6.5 nor raised above 8.5.

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (SLR-MLS)

Temporal Representation:

The samples were collected between the dates of 2010-10-19 and 2017-06-01

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency for NPDES Receiving Water Monitoring

QAPP Information Reference(s):

Quality Assurance Project Plan for the County of San Diego's Inland Surface Water Monitoring Program

QAPP Information Reference(s):

Quality Assurance Project Plan Equivalency Los Penasquitos Watershed Management Area Sediment Load Total Maximum Daily Load


DECISION ID	81478	Region 9
Santa Margarita River (Lower)

Pollutant:	2-Methylnaphthalene
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	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of the four samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 the four samples exceed the water quality objective and 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:	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 81478, 2-Methylnaphthalene	Region 9
Santa Margarita River (Lower)

LOE ID:

78321

Pollutant:

2-Methylnaphthalene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for 2-Methylnaphthalene.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278

Evaluation Guideline:

In marine and estuarine sediments the probable effect level (predictive of sediment toxicity for sediment-dwelling organisms) for 2-Methylnaphthalene is 201.28 ng/g dry weight (MacDonald et al., 1996).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.


DECISION ID	81575	Region 9
Santa Margarita River (Lower)

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)(2016)
Revision Status	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of the four samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 the four samples exceed the water quality objective and 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:	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 81575, Benzo(a)anthracene	Region 9
Santa Margarita River (Lower)

LOE ID:

78324

Pollutant:

Benzo(a)anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Benzo(a)anthracene.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278

Evaluation Guideline:

In marine and estuarine sediments the probable effect level (predictive of sediment toxicity for sediment-dwelling organisms) for Benzo(a)anthracene is 692.53 ng/g dry weight (MacDonald et al., 1996).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.


DECISION ID	81315	Region 9
Santa Margarita River (Lower)

Pollutant:	Chlordane
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	Original
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. 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. Zero of the five samples exceed the water quality 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. Zero of the five samples exceed the water quality objective and 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:	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 81315, Chlordane	Region 9
Santa Margarita River (Lower)

LOE ID:

78326

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Chlordane, Total.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

The potential for biological effects of sediment-sorbed contaminants tested in the National Status of Trends Program. NOAA Technical Memorandum NOS OMA 52. Seattle, WA: National Oceanic and Atmospheric Administration

Evaluation Guideline:

In marine and estuarine sediments the effects range median (predictive of sediment toxicity for sediment-dwelling organisms) for Total Chlordane is 6 ng/g dry weight (Long and Morgan, 1990).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 81315, Chlordane	Region 9
Santa Margarita River (Lower)

LOE ID:

72833

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:

0 of 1 samples collected exceeded the criteria for chlordane concentration (Sum of trans-Chlordane, cis-Chlordane, cis-Nonachlor, trans-Nonachlor, and Oxychlordane).

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. Waters shall not contain substances in concentrations that result in the deposition of material that causes nuisance or adversely affects beneficial uses. (Water Quality Control Plan for the San Diego Basin).

Objective/Criterion Reference:

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

Evaluation Guideline:

The Probable Effect Concentration for Chlordane in freshwater sediments is 17.6 ug/kg(MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data were collected at the following station 902SSMR07 (Santa Margarita at Basilone Rd).

Temporal Representation:

The samples were collected on 5/21/2008.

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	100515	Region 9
Santa Margarita River (Lower)

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)(2016)
Revision Status	Original
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 lines of evidence is available in the administrative record to assess this pollutant. zero of the four samples exceed the water quality 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. Zero of four samples exceeded the water quality objective and 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:	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 100515, Chrysene (C1-C4)	Region 9
Santa Margarita River (Lower)

LOE ID:

78332

Pollutant:

Chrysene (C1-C4)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Chrysene.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278

Evaluation Guideline:

In marine and estuarine sediments the probable effect level (predictive of sediment toxicity for sediment-dwelling organisms) for Chrysene is 845.98 ng/g dry weight (MacDonald et al., 1996).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.


DECISION ID	100525	Region 9
Santa Margarita River (Lower)

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)(2016)
Revision Status	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 one sample exceed the objective and 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:	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 100525, DDD (Dichlorodiphenyldichloroethane)	Region 9
Santa Margarita River (Lower)

LOE ID:

76480

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDD.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDD (o,p' + p,p') is 28.0 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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	81788	Region 9
Santa Margarita River (Lower)

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
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	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 one sample exceed the objective and 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:	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 81788, DDE (Dichlorodiphenyldichloroethylene)	Region 9
Santa Margarita River (Lower)

LOE ID:

76481

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDE.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDE (o,p' + p,p') is 31.3 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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	81842	Region 9
Santa Margarita River (Lower)

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
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	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 one sample exceed the objective and 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:	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 81842, DDT (Dichlorodiphenyltrichloroethane)	Region 9
Santa Margarita River (Lower)

LOE ID:

76482

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDT.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for sum of DDT (o,p' + p,p') is 62.9 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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	81844	Region 9
Santa Margarita River (Lower)

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)(2016)
Revision Status	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of four samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 four samples exceed the objective and 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:	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 81844, Dibenz[a,h]anthracene	Region 9
Santa Margarita River (Lower)

LOE ID:

78307

Pollutant:

Dibenz[a,h]anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Dibenzo(a, h)anthracene.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97

Evaluation Guideline:

In marine and estuarine sediments the effects range median (predictive of sediment toxicity for sediment-dwelling organisms) for Dibenzo(a, h)anthracene is 260 ng/g dry weight (Long et al., 1995).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.


DECISION ID	81950	Region 9
Santa Margarita River (Lower)

Pollutant:	Dieldrin
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	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 one sample exceed the objective and 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:	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 81950, Dieldrin	Region 9
Santa Margarita River (Lower)

LOE ID:

76461

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Dieldrin.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for dieldrin is 61.8 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the 2002 QAMP.

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	81951	Region 9
Santa Margarita River (Lower)

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)(2016)
Revision Status	Original
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. 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. Zero of the two samples exceed the objective. Zero of two samples exhibited sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 the two samples exceed the objective, and 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:	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 81951, Endrin	Region 9
Santa Margarita River (Lower)

LOE ID:

78310

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: a total of 5 samples were collected and they were all non-detect, however 3 samples were not used in analysis because when the method detection limit was organic carbon normalized, the results were above the guideline and therefore could not be quanitified with the level of certainty required by the Listing Policy.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Technical basis for deriving sediment criteria for nonionic organic contaminants for the protection of benthic organisms by using equilibrium partitioning. EPA822-R-93-011. Washington, D.C.: Office of Water, USEPA

Evaluation Guideline:

In marine and estuarine sediments the sediment quality guideline (predictive of sediment toxicity for sediment-dwelling organisms) for Endrin is 0.76 ug/g oc (Fairey et al., 2001).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 81951, Endrin	Region 9
Santa Margarita River (Lower)

LOE ID:

76462

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Endrin.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for endrin is 207 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the 2002 QAMP.

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	81270	Region 9
Santa Margarita River (Lower)

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)(2016)
Revision Status	Original
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. 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. Zero of the two samples exceed the objective. Zero of five samples exhibited sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 the five samples exceed the objective, and 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:	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 81270, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 9
Santa Margarita River (Lower)

LOE ID:

77837

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for HCH, gamma.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for Lindane (gamma-HCH) is 4.99 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the 2002 QAMP.

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 81270, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 9
Santa Margarita River (Lower)

LOE ID:

78317

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for HCH, Gamma.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

An evaluation of methods for calculating mean sediment quality guideline quotients as indicators of contamination and acute toxicity to amphipods by chemical mixtures. Environmental Toxicology and Chemistry. 20(10): 2276-2286

Evaluation Guideline:

In marine and estuarine sediments the sediment quality guideline (predictive of sediment toxicity for sediment-dwelling organisms) for HCH, gamma(Lindane; BHC, gamma) is 0.37 ug/g oc (Fairey et al., 2001).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.


DECISION ID	81217	Region 9
Santa Margarita River (Lower)

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)(2016)
Revision Status	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of one sample exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 one sample exceed the objective and 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:	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 81217, Methyl Parathion	Region 9
Santa Margarita River (Lower)

LOE ID:

77912

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Parathion, Methyl.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Evaluation Guideline:

The evaluation guideline for methyl parathion is the median lethal concentration (LC50) of 6 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 6 ug/g is the geometric mean of LC50 values for methyl parathion from Ding et al. (2011).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita at Basilone Rd - 902SSMR07]

Temporal Representation:

Data was collected on a single day 5/21/2008.

Environmental Conditions:

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

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP 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	81532	Region 9
Santa Margarita River (Lower)

Pollutant:	Nitrate/Nitrite (Nitrite + Nitrate as N)
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	Original
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. One line of evidence is available in the administrative record to assess this pollutant. Zero of the six samples exceed the water quality 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. Zero of six samples exceeded the water quality objective and 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 iare 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:	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 81532, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 9
Santa Margarita River (Lower)

LOE ID:

77867

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants from the County of San Diego Department of Public Works Watershed Protection Program, 2001-2008.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrate + nitrite (as N) is 10.0 mg/L (Title 22 of the California Code of Regulations).

Objective/Criterion Reference:

Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 1 monitoring site [ Santa Margarita River - 902SMR-MLS]

Temporal Representation:

Data was collected over the time period 11/29/2001-2/28/2006.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):


DECISION ID	81431	Region 9
Santa Margarita River (Lower)

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:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of the four samples exceed the evaluation guideline for total PAHs, Zero of four samples exceeded the evaluation guideline for low molecular weight PAhs, and zero of four samples exceeded the evaluation guideline for high molecular weight PAHs. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 the 4 samples exceed the objective, and 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:	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 81431, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 9
Santa Margarita River (Lower)

LOE ID:

78343

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for PAHs (Polycyclic Aromatic Hydrocarbons).

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Quality Assurance Project Plan from Southern California Bight.

Evaluation Guideline:

In marine and estuarine sediments the sediment quality guideline (predictive of sediment toxicity for sediment-dwelling organisms) for Total PAHs is 1800 ug/g (Fairey et al., 2001).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 81431, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 9
Santa Margarita River (Lower)

LOE ID:

78341

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine 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:

Incidence of adverse biological effects within ranges of chemical concentrations in marine and estuary sediments. Environmental Management. 19, (1): 81-97

Evaluation Guideline:

In marine and estuarine sediments the effects range median (predictive of sediment toxicity for sediment-dwelling organisms) for High molecular weight PAHs is 9600 ng/g dry weight (Long et al., 1995).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 81431, PAHs (Polycyclic Aromatic Hydrocarbons)	Region 9
Santa Margarita River (Lower)

LOE ID:

78342

Pollutant:

PAHs (Polycyclic Aromatic Hydrocarbons)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine 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:

Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278

Evaluation Guideline:

In marine and estuarine sediments the effects range median (predictive of sediment toxicity for sediment-dwelling organisms) for Low molecular weight PAHs is 1442 ng/g dry weight (Long et al., 1995).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.


DECISION ID	81322	Region 9
Santa Margarita River (Lower)

Pollutant:	PCBs (Polychlorinated biphenyls)
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	Original
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. 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. Zero of the two samples exceed the objective. Zero of five samples exhibited sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 the five samples exceed the objective, and 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:	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 81322, PCBs (Polychlorinated biphenyls)	Region 9
Santa Margarita River (Lower)

LOE ID:

78344

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for PCB, Total.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls. Environmental Toxicology and Chemistry. 19(5): 1403-1413

Evaluation Guideline:

In marine and estuarine sediments the sediment quality guideline (predictive of sediment toxicity for sediment-dwelling organisms) for Total PCBs is 400 ng/g (MacDonald et al., 2000b).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.

Line of Evidence (LOE) for Decision ID 81322, PCBs (Polychlorinated biphenyls)	Region 9
Santa Margarita River (Lower)

LOE ID:

72813

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:

Zero of 1 sample collected for Total PCBs exceeded the evaluation guideline.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity) for total PCB is 676 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Spatial Representation:

Data were collected at the following station 902SSMR07 (Santa Margarita at Basilone Rd).

Temporal Representation:

The samples were collected on 5/21/2008.

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	81479	Region 9
Santa Margarita River (Lower)

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)(2016)
Revision Status	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of the four samples exceed the objective. Zero of four samples exhibited sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 the four samples exceed the objective, and 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:	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 81479, Phenanthrene	Region 9
Santa Margarita River (Lower)

LOE ID:

78345

Pollutant:

Phenanthrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Phenanthrene.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278

Evaluation Guideline:

In marine and estuarine sediments the probable effect level (predictive of sediment toxicity for sediment-dwelling organisms) for Phenanthrene is 543.53 ng/g dry weight (MacDonald et al., 1996).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.


DECISION ID	81480	Region 9
Santa Margarita River (Lower)

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)(2016)
Revision Status	Original
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. 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of the four samples exceed the objective. Zero of four samples exhibited sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for 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 the four samples exceed the objective, and 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:	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 81480, Pyrene	Region 9
Santa Margarita River (Lower)

LOE ID:

78346

Pollutant:

Pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Estuarine Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Bight data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 4 samples exceed the criterion for Pyrene.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Development and evaluation of sediment quality guidelines for Florida coastal waters. Ecotoxicology 5: 253-278

Evaluation Guideline:

In marine and estuarine sediments the probable effect level (predictive of sediment toxicity for sediment-dwelling organisms) for Pyrene is 1397.4 ng/g dry weight (MacDonald et al., 1996).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Santa Margarita River (Lower) was collected at 4 monitoring sites [ 902_6317, 902_6303, 902_6311, 902_6314]

Temporal Representation:

Data was collected on a single day 8/29/2008.

Environmental Conditions:

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

QAPP Information:

The Quality Assurance Project Plan from Southern California Bight was followed.

QAPP Information Reference(s):

Quality Assurance Project Plan from Southern California Bight.


DECISION ID	77006	Region 9
Santa Margarita River (Lower)

Pollutant:	Sulfates
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	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The decision has not changed from the previous listing cycle. No new data were assessed for the current listing cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the 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. One line of evidence is available in the administrative record to assess this pollutant. Two of the five samples exceed the Basin Plan water quality objective for sulfates. 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. Two of the five samples exceed the Basin Plan water quality objective for sulfates and 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 26 samples is needed to determine if a beneficial use is fully supported using table 3.2. 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:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

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 77006, Sulfates	Region 9
Santa Margarita River (Lower)

LOE ID:

21195

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical monitoring (conventional pollutants only)

Data Used to Assess Water Quality:

Five water samples were collected at Santa Margarita River 10 Station 902SSMR10 on January 2003, April 2003, May 2003, and September 2003, Two of the five showed excessive sulfate concentrations according to results in California's Surface Water Ambient Monitoring Program Report, 2007.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The recommended secondary drinking water standard for sulfate is 250 mg/l.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA

Spatial Representation:

Water samples were collected at Santa Margarita River 10 Station 902SSMR10; (Latitude 33.2370, Longitude -117.3923).

Temporal Representation:

Samples were collected on January 2003, April 2003, May 2003, and September 2003.

Environmental Conditions:

Samples were collected during wet weather.

QAPP Information:

Quality control for the chemical analysis portion of this study was conducted in accordance with the California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):


DECISION ID	81752	Region 9
Santa Margarita River (Lower)

Pollutant:	Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
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	Original
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. One line of evidence is available in the administrative record to assess this pollutant. Zero of the one sample exceed the 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. Zero of one sample exceeded the objective and 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:	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 81752, Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)	Region 9
Santa Margarita River (Lower)

LOE ID:

76543

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:

Preservation of Rare & Endangered Species

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP data for Santa Margarita River (Lower) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDT, Total.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference: