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

Supporting Information

Regional Board 3 - Central Coast Region

Water Body Name:	Tequisquita Slough
Water Body ID:	CAR3053002020011121091332
Water Body Type:	River & Stream


DECISION ID	126621	Region 3
Tequisquita Slough

Pollutant:	Ammonia
Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Reason for Delisting:	Applicable WQS attained; reason for recovery unspecified
TMDL Name:	Pajaro River Watershed Nutrients
TMDL Project Code:	999
Expected TMDL Completion Date:	2018
Date TMDL Approved by USEPA:	10/06/2016
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under sections 2.2 and 4.1 of the Listing Policy. Under section 4.1 a single line of evidence is necessary to assess listing status. Seven lines of evidence (LOEs) are available in the administrative record to assess this pollutant. Sample and exceedance counts for the lines of evidence with the fraction identified as “none” or “not recorded” are grouped together with those having the fraction “total”, based on the analytical method used. The following is a summary of the sample and exceedances for each beneficial use: Based on LOEs summarizing un-ionized ammonia data, five of the 105 samples exceed the water quality objective (Basin Plan) set to protect aquatic life. Based on LOEs summarizing total ammonia data (‘nitrogen, ammonia’ and ‘nitrogen as ammonia’) two of the 44 samples exceed the EPA's Aquatic Life Ambient Water Quality Criteria set to protect aquatic life. Based on the readily available data and information, the weight of evidence indicates that the water body-pollutant combination should be removed from the section 303(d) List because applicable water quality standards for the pollutant are met. In accordance with section 2.2 of the Policy, there is sufficient justification to place it in the Being Addressed portion of the 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Five of the 105 un-ionized ammonia samples and two of the 44 total ammonia samples exceed the water quality objectives, however this does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. The Pajaro River Watershed Nutrients TMDL was adopted by the USEPA on 10/06/2016. 5. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) List because applicable water quality standards for the pollutant are not being exceeded. There is sufficient justification to place it in the Being Addressed portion of the 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard

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 126621, Ammonia	Region 3
Tequisquita Slough

LOE ID:

13652

Pollutant:

Ammonia (Unionized)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCWQP Northern Area Ag-Waiver Monitoring (R3_CMPNorth) data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Ammonia as N, Unionized.

Data Reference:

Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data

Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin General Objective, Chapter III, Section II.A.2 (General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/l (as N) in receiving waters (page III-4) .

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tesquisquita Slough at Shore Road]

Temporal Representation:

Data was collected over the time period 2/21/2006-3/28/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).

Environmental Conditions:

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

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). QA data are included in submission. All data are flagged as appropriate.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 126621, Ammonia	Region 3
Tequisquita Slough

LOE ID:

219429

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 RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and the results are as follows: 2 of the 67 samples exceeded the water quality threshold for Ammonia as N, Unionized. Although a total of 69 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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin General Objective, Chapter 3, Section 3.3.2 (Objectives for all Inland Surface Waters, Enclosed Bays, and Estuaries) states that the discharge of wastes shall not cause concentrations of unionized ammonia (NH3) to exceed 0.025 mg/L (as N) in receiving waters (page 32).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR).

Temporal Representation:

Data for this waterbody was collected over the date range 2010-04-26 to 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 126621, Ammonia	Region 3
Tequisquita Slough

LOE ID:

9179

Pollutant:

Ammonia (Unionized)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Tequisquita Slough to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Ammonia as N, Unionized.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TES-Tequisquita Slough at Shore Road].

Temporal Representation:

Data was collected over the time period 12/18/1997-12/16/1998. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.

Environmental Conditions:

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

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. All data are flagged as appropriate.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 126621, Ammonia	Region 3
Tequisquita Slough

LOE ID:

58595

Pollutant:

Ammonia (Unionized)

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 CMP data for Tequisquita Slough to determine beneficial use support and results are as follows: 1 of 9 samples exceed the criterion for Ammonia as N, Unionized.

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ Tequisquita Slough - 305TSR]

Temporal Representation:

Data was collected over the time period 4/27/2009-12/29/2009.

Environmental Conditions:

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

QAPP Information:

The data was collected for the CCRWQCB Cooperative Monitoring Program for Agriculture data and provided in SWAMP format.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 126621, Ammonia	Region 3
Tequisquita Slough

LOE ID:

48875

Pollutant:

Ammonia (Unionized)

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:

Central Coast Water Board Staff assessed public submissions data for Tequisquita Slough to determine beneficial use support and results are as follows: 1 of 12 samples exceed the criterion for Ammonia as N, Unionized.

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tequisquita Slough at Shore Rd]

Temporal Representation:

Data was collected over the time period 4/27/2009-3/31/2010.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the Cooperative Monitoring Program QAPP, (Clark and Ogle 2006). All data are flagged as appropriate.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 126621, Ammonia	Region 3
Tequisquita Slough

LOE ID:

149462

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 Surface Water Monitoring Project data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Ammonia as N, Unionized. 3 of these samples were estimates.

Data Reference:

CMP water quality data 10/17/2018--12/20/2018.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station. Station Code(s): 305TSR

Temporal Representation:

Data for this waterbody were collected between 2018-10-24 and 2018-12-19

Environmental Conditions:

QAPP Information:

Data was collected verified in accordance with the Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program,

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 126621, Ammonia	Region 3
Tequisquita Slough

LOE ID:

184468

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 2 of 44 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 3.

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 (305TSR)

Temporal Representation:

The samples were collected between the dates of 2010-05-26 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107461	Region 3
Tequisquita Slough

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:	No Source Analysis Available
Expected TMDL Completion Date:	2035
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) List under sections 4.1 and 4.6 of the Listing Policy. Under 4.1 of the Policy, a minimum of one line of evidence is needed to assess listing status. Eight lines of evidence are available in the administrative record to assess this pollutant. One sample can have multiple toxicity test results (or endpoints) but will be counted only once. One sample is defined as being collected on the same day at the same location. Five LOEs summarize water samples. Six out of 36 samples were toxic to test organisms (exhibited a significant increase in mortality, decrease in cell density, decrease in growth or reproduction compared to the laboratory control) and therefore exceeded the narrative general water quality objective for toxicity, set to protect for aquatic life beneficial uses. Three LOEs summarize sediment samples. Two out of 11 samples were toxic to test organisms (exhibited a significant increase in mortality, decrease in cell density, decrease in growth or reproduction compared to the laboratory control) and therefore exceeded the narrative general water quality objective for toxicity, set to protect for aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates 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. 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. Six out of 36 water samples, and two of the 11 sediment samples, were toxic to test organisms relative to the control 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 107461, Toxicity	Region 3
Tequisquita Slough

LOE ID:

24654

Pollutant:

Invertebrate Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCWQP Northern Area Ag-Waiver Monitoring (R3_CMPnorth) data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Toxicity, Hyalella azteca Survival (%) 10 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).

Data Reference:

Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data

Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data

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. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, toxicity bioassays of appropriate duration, or other appropriate methods as specified by the Regional Board (Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.

Guideline Reference:

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)

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tesquisquita Slough at Shore Road]

Temporal Representation:

Data was collected on a single day 5/18/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107461, Toxicity	Region 3
Tequisquita Slough

LOE ID:

148923

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

1 of the 7 samples collected by RWB3 Cooperative Monitoring Program for Tequisquita Slough exhibited toxicity. A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Hyalella azteca, for Growth (wt/surv indiv), Hyalella azteca, for Survival

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 station. Monitoring site: ( 305TSR )

Temporal Representation:

The samples were collected between the dates of 2013-05-30 and 2018-04-23.

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107461, Toxicity	Region 3
Tequisquita Slough

LOE ID:

58608

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:

Eleven samples were collected to evaluate water toxicity. Five of the eleven samples exhibited significant toxicity. The toxicity tests for the samples included survival and reproduction of Ceriodaphnia dubia, survival and growth of Pimephales promelas and total cell count (growth) of Selenastrum capricornutum. 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. The sample collected on 1/24/08 exhibited significant toxicity to Pimephales promelas growth. Four samples collected on 9/30/08, 1/27/09, 8/25/09 and 9/30/09 exhibited significant toxicity to Ceriodaphnia dubia reproduction. It should be noted that the samples collected in 2006, in the data file associated with this LOE, are not included in this LOE because they were included in the previous assessment cycle.

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

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:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Significant effect is defined here using a two-tier approach consistent with the method used by the SWAMP program. The effect must be significant when compared to the control sample based on statistical test alpha level of 0.05 (Probability field in data set) AND the mean must be more than 20 percent different from the control (PercentControl field in data set).

Guideline Reference:

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

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 305TSR Tequisquita Slough at Shore Road.

Temporal Representation:

The samples were collected from October 2007 to March 2010.

Environmental Conditions:

QAPP Information:

The data was collected for the CCRWQCB Cooperative Monitoring Program for Agriculture data and provided in SWAMP format. QAPP for the Cooperative Monitoring program for Agriculture in Region 3.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107461, Toxicity	Region 3
Tequisquita Slough

LOE ID:

58607

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Three samples were collected to evaluate sediment toxicity. One of the three samples exhibited significant toxicity to Hyalella azteca survival. The toxicity tests included growth and 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. It should be noted that the samples collected in 2006, in the data file associated with this LOE, are not included in this LOE because they were included in the previous assessment cycle.

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

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:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064

Spatial Representation:

The samples were collected at 305TSR Tequisquita Slough.

Temporal Representation:

The samples were collected in annually from April 2007 to April 2009.

Environmental Conditions:

QAPP Information:

The data was collected for the CCRWQCB Cooperative Monitoring Program for Agriculture data and provided in SWAMP format. QAPP for the Cooperative Monitoring program for Agriculture in Region 3.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107461, Toxicity	Region 3
Tequisquita Slough

LOE ID:

24657

Pollutant:

Plant Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCWQP Northern Area Ag-Waiver Monitoring (R3_CMPnorth) data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Selenastrum capricornutum Growth (Cell Density) 4 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).

Data Reference:

Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data

Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Significant reduction in cell count of test organism relative to the control (alpha < 0.05) and cell count <80% of control.

Guideline Reference:

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)

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tesquisquita Slough at Shore Road]

Temporal Representation:

Data was collected over the time period 2/21/2006-9/26/2006. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107461, Toxicity	Region 3
Tequisquita Slough

LOE ID:

24652

Pollutant:

Invertebrate Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCWQP Northern Area Ag-Waiver Monitoring (R3_CMPnorth) data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Ceriodaphnia dubia Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).

Data Reference:

Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data

Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.

Guideline Reference:

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)

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tesquisquita Slough at Shore Road].

Temporal Representation:

Data was collected between 2/21/06 and 9/21/06. Cooperative Monitoring Program (CMP) staff conduct monitoring for conventional pollutants at all Ag Waiver monitoring sites monthly. CMP staff also conduct water toxicity monitoring quarterly and sediment toxicity monitoring annually (in spring).

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107461, Toxicity	Region 3
Tequisquita Slough

LOE ID:

24656

Pollutant:

Vertebrate Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCWQP Northern Area Ag-Waiver Monitoring (R3_CMPnorth) data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 3 samples exceed the criterion for Toxicity, Pimephales promelas Survival (%) 7 days. Toxicity is defined by SWAMP (2004) as follows: Significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%, and less than the evaluation threshold (both criteria are met).

Data Reference:

Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data

Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.

Guideline Reference:

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)

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tesquisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107461, Toxicity	Region 3
Tequisquita Slough

LOE ID:

148893

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 22 samples collected by RWB3 Cooperative Monitoring Program for Tequisquita Slough 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: Ceriodaphnia dubia, for Young/female, Selenastrum capricornutum, for Total Cell Count, Ceriodaphnia dubia, for Survival, Thalassiosira pseudonana, for Total Cell Count, Pimephales promelas, for Survival, Hyalella azteca, for Survival, Pimephales promelas, for Biomass (wt/orig indiv), Cyprinodon variegatus, for Biomass (wt/orig indiv), Cyprinodon variegatus, for Survival, Chironomus dilutus, for Survival

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Significant reduction of survival of test organism relative to the control (alpha < 0.05) and test organism survival is 20% less than the control survival.

Guideline Reference:

SWAMP_Memo_Toxicity_Data_Intrepretation

Spatial Representation:

The samples were collected at 1 station. Monitoring site: ( 305TSR )

Temporal Representation:

The samples were collected between the dates of 2013-03-28 and 2018-04-23.

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107463	Region 3
Tequisquita Slough

Pollutant:	Turbidity
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:	No Source Analysis Available
Expected TMDL Completion Date:	2035
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the Clean Water Act (CWA) section 303(d) List under section 4.2 of the Listing Policy. Under section 4.2 a single line of evidence is necessary to assess listing status. A total of five lines of evidence are available in the administrative record to assess this pollutant. Sample and exceedance counts for the lines of evidence with the fraction identified as “none” or “not recorded” are grouped together with those having the fraction “total”, based on the analytical method used. Once summed, a total of 97 of 177 samples exceed the evaluation guideline for warm freshwater habitat (Shoup, D.E. and Wahl D.H., 2009) used to interpret the water quality objectives for the aquatic life beneficial use. 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. 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. A total of 97 of 177 samples exceed the evaluation guideline for warm freshwater habitat and this exceeds the allowable frequency listed in Table 4.2 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 not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Line of Evidence (LOE) for Decision ID 107463, Turbidity	Region 3
Tequisquita Slough

LOE ID:

12072

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Tequisquita Slough to determine beneficial use support and results are as follows: 11 of 11 samples exceed the criterion for Turbidity(NTU).

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Water Quality Control Plan, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.

Guideline Reference:

Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TES-Tequisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107463, Turbidity	Region 3
Tequisquita Slough

LOE ID:

182301

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 28 of 94 samples exceeded the water quality threshold for Turbidity.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009).

Guideline Reference:

The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2010-04-26 and 2018-12-19

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107463, Turbidity	Region 3
Tequisquita Slough

LOE ID:

17503

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Tequisquita Slough to determine beneficial use support and results are as follows: 42 of 44 samples exceed the criterion for Turbidity(NTU).

Data Reference:

Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A

Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.

Guideline Reference:

Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 2 monitoring sites [ TS-SHO - Tequisquita Slough at Shore Rd., at Lake Rd]

Temporal Representation:

Data was collected over the time period 9/28/2005-1/24/2007.

Environmental Conditions:

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

QAPP Information:

Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107463, Turbidity	Region 3
Tequisquita Slough

LOE ID:

13629

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCWQP Northern Area Ag-Waiver Monitoring (R3_CMPNorth) data for Tequisquita Slough to determine beneficial use support and results are as follows: 4 of 5 samples exceed the criterion for Turbidity(NTU).

Data Reference:

Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data

Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Sigler et al. (1984) states that turbidities of 25 NTU's or greater caused reduction in juvenile salmonid growth due to interference with their ability to find food.

Guideline Reference:

Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tesquisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107463, Turbidity	Region 3
Tequisquita Slough

LOE ID:

48902

Pollutant:

Turbidity

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:

Central Coast Water Board Staff assessed public submissions data for Tequisquita Slough to determine beneficial use support and results are as follows: 12 of 23 samples exceed the criterion for Turbidity(NTU).

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Turbidities of 40 NTU or greater can cause a reduction in piscivorous fish (largemouth bass) growth due to interference with their ability to find food (Shoup, D.E. and Wahl D.H., 2009).

Guideline Reference:

The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tequisquita Slough at Shore Rd]

Temporal Representation:

Data was collected over the time period 2/13/2007-6/30/2010.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107456	Region 3
Tequisquita Slough

Pollutant:	pH
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:	No Source Analysis Available
Expected TMDL Completion Date:	2035
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the Clean Water Act section 303(d) List under sections 4.2 of the Listing Policy. Under this section, a single line of evidence is necessary to assess listing status. Fifteen lines of evidence are available in the administrative record to assess this pollutant. Forty-three of the 259 samples exceed the maximum pH water quality objective for Contact and Non-Contact Recreation beneficial uses. Fifteen of the 259 samples exceed the maximum pH water quality objective for Warm Freshwater Habitat. 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. 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. Forty-three of the 259 samples exceed the maximum pH water quality objective for Contact and Non-contact Recreation beneficial uses, 15 of the 259 samples exceed the maximum pH water quality objective for Warm Freshwater Habitat and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be 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 107456, pH	Region 3
Tequisquita Slough

LOE ID:

11278

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Tequisquita Slough to determine beneficial use support and results are as follows: 1 of 13 samples exceed the criterion for pH.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, the pH value shall not be depressed below 7.0 or raised above 8.5.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TES-Tequisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

13671

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data

Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for water contact recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: pH value shall neither be depressed below 6.5 nor raised above 8.3.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tesquisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

11276

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Tequisquita Slough to determine beneficial use support and results are as follows: 4 of 13 samples exceed the criterion for pH.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TES-Tequisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

17750

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

122

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A

Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 2 monitoring sites [ TS-SHO - Tequisquita Slough at Shore Rd., at Lake Rd]

Temporal Representation:

Data was collected over the time period 12/23/2002-1/24/2007.

Environmental Conditions:

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

QAPP Information:

Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

48890

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Water Board Staff assessed public submissions data for Tequisquita Slough to determine beneficial use support and results are as follows: 9 of 22 samples exceed the criterion for pH.

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall neither be depressed below 6.5 nor raised above 8.3 (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tequisquita Slough at Shore Rd]

Temporal Representation:

Data was collected over the time period 2/13/2007-6/30/2010.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

178991

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 RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 4 of 97 samples exceeded the water quality threshold for pH.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for warm fresh water habitat (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 7.0 nor raised above 8.5.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2010-04-26 and 2018-12-19

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

177769

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 7 of 97 samples exceeded the water quality threshold for pH.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 6.5 nor raised above 8.3.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2010-04-26 and 2018-12-19

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

177839

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for water contact recreation (Section 3.3.2 Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries) states that the pH value shall neither be depressed below 6.5 nor raised above 8.3.

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2010-04-26 and 2018-12-19

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

11277

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TES-Tequisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

13673

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data

Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tesquisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

17752

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

122

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A

Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 2 monitoring sites [ TS-SHO - Tequisquita Slough at Shore Rd., at Lake Rd]

Temporal Representation:

Data was collected over the time period 12/23/2002-1/24/2007.

Environmental Conditions:

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

QAPP Information:

Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

48901

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:

Central Coast Water Board Staff assessed public submissions data for Tequisquita Slough to determine beneficial use support and results are as follows: 5 of 22 samples exceed the criterion for pH.

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall not be depressed below 7.0 or raised above 8.5 (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tequisquita Slough at Shore Rd]

Temporal Representation:

Data was collected over the time period 2/13/2007-6/30/2010.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

13672

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data

Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tesquisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

48891

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Water Board Staff assessed public submissions data for Tequisquita Slough to determine beneficial use support and results are as follows: 9 of 22 samples exceed the criterion for pH.

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH value shall neither be depressed below 6.5 nor raised above 8.3 (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tequisquita Slough at Shore Rd]

Temporal Representation:

Data was collected over the time period 2/13/2007-6/30/2010.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107456, pH	Region 3
Tequisquita Slough

LOE ID:

17751

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

122

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A

Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 2 monitoring sites [ TS-SHO - Tequisquita Slough at Shore Rd., at Lake Rd]

Temporal Representation:

Data was collected over the time period 12/23/2002-1/24/2007.

Environmental Conditions:

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

QAPP Information:

Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.

QAPP Information Reference(s):


DECISION ID	131025	Region 3
Tequisquita Slough

Pollutant:	Fecal Coliform
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)(2018)
Revision Status	Revised
Sources:	Collection System Failure \| Domestic Animals/Livestock \| Urban Runoff/Storm Sewers
TMDL Name:	Pajaro River Fecal Coliform (including San Benito R., Llagas Cr., and Tequesquita Slough)
TMDL Project Code:	669
Date TMDL Approved by USEPA:	08/03/2010
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 of the Listing Policy due to a change in water quality standards. The State Water Boards 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: where the salinity level of a waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies; and where the salinity level of a waterbody is greater than 1 part per thousand 95 percent or more of the time, the Enterococci bacteria objective applies. These objectives supersede the fecal coliform water quality objective for water contact recreation. Consequently, the fecal coliform objective for water contact recreation is no longer applicable to this waterbody and those LOEs have been removed from this decision. However, one line of evidence (LOE) is available in the administrative record to assess this pollutant and the non-contact recreation use. Eight of the 12 samples exceed the water quality objective for non-contact recreation. After review of the available data and information for the non-contact recreation beneficial use, RWQCB staff concludes that the water body-pollutant combination should not be removed from the CWA section 303(d) List because applicable water quality standards for the pollutant are being exceeded. In accordance with section 2.2 of the Policy, there is sufficient justification to place it in the Being Addressed portion of the 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eight of the 12 samples exceed the water quality objective for non-contact recreation, and this does exceed the allowable frequency listed in Table 4.2 of the Listing Policy. 4. The Pajaro River Fecal Coliform TMDL has been approved by USEPA on 08/03/2010. 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. This water body pollutant combination should be placed in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard.

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 131025, Fecal Coliform	Region 3
Tequisquita Slough

LOE ID:

11275

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:

Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Tequisquita Slough to determine beneficial use support and results are as follows: 8 of 12 samples exceed the criterion for Coliform, Fecal.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan, Central Coast Basin objective for non-contact water recreation uses (Section II.A.2. Objectives for All Inland Surface Waters, Enclosed Bays, and Estuaries, II.A.2.a) states the following: Fecal coliform concentration, based on a minimum of not less than five samples for any 30-day period, shall not exceed a log mean of 2000/100 ml, nor shall more than ten percent of samples collected during any 30-day period exceed 4000/100 ml.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TES-Tequisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):


DECISION ID	107454	Region 3
Tequisquita Slough

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	Agriculture \| Domestic Animals/Livestock \| Natural Sources
TMDL Name:	Pajaro River Watershed Nutrients
TMDL Project Code:	999
Expected TMDL Completion Date:	2018
Date TMDL Approved by USEPA:	10/06/2016
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) List under sections 2.2 and 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Seven lines of evidence are available in the administrative record to assess this pollutant. Fifty-one of 121 samples exceed the water quality objective for fish spawning (Basin Plan). Forty-two of 263 samples exceed the water quality objective for warm freshwater habitat (Basin Plan). Note that there is no difference between samples fractions ‘dissolved’ and ‘total,’ therefore sample and exceedance counts will be summed for the purpose of this decision. Previous decisions (pre-2020) included dissolved oxygen saturation LOEs as ancillary evidence. This decision will no longer include dissolved oxygen saturation and these LOEs will be retired next cycle. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Fifty-one of 121 samples exceed the fish spawning objective. This exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. The Pajaro River watershed nutrients TMDL was approved by the USEPA on October 6, 2016. 5. 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. Furthermore, this pollutant waterbody combination should be placed in the 'Being Addressed' portion of the 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard.

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 107454, Oxygen, Dissolved	Region 3
Tequisquita Slough

LOE ID:

13654

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCWQP Northern Area Ag-Waiver Monitoring (R3_CMPNorth) data for Tequisquita Slough to determine beneficial use support and results are as follows: 1 of 5 samples exceed the criterion for Oxygen, Dissolved.

Data Reference:

Final Data File used for assessment: Central Coast Water Quality Preservation Inc water quality data

Final Data File used for assessment: Central Coast Water Quality Preservation Inc toxicity data

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tesquisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107454, Oxygen, Dissolved	Region 3
Tequisquita Slough

LOE ID:

174270

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 47 of 99 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2010-04-26 and 2018-12-19

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107454, Oxygen, Dissolved	Region 3
Tequisquita Slough

LOE ID:

17823

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

121

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed Monterey Area Research Consortium (R3_MARC) data for Tequisquita Slough to determine beneficial use support and results are as follows: 26 of 121 samples exceed the criterion for Oxygen, Dissolved.

Data Reference:

Final Data File used for assessment: Marc Los Huertos Water Quality Data, file A

Final Data File used for assessment: Marc Los Huertos Water Quality Data, file B

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 2 monitoring sites [ TS-SHO - Tequisquita Slough at Shore Rd., at Lake Rd]

Temporal Representation:

Data was collected over the time period 12/23/2002-1/24/2007.

Environmental Conditions:

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

QAPP Information:

Regional Board approved QAPP. Multiple errors were identified in data and were flagged or fixed by RB staff (in communication with Project staff) prior to assessment of data.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107454, Oxygen, Dissolved	Region 3
Tequisquita Slough

LOE ID:

48888

Pollutant:

Oxygen, Dissolved

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:

Central Coast Water Board Staff assessed public submissions data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 22 samples exceed the criterion for Oxygen, Dissolved.

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tequisquita Slough at Shore Rd]

Temporal Representation:

Data was collected over the time period 2/13/2007-6/30/2010.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107454, Oxygen, Dissolved	Region 3
Tequisquita Slough

LOE ID:

174681

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 12 of 99 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2010-04-26 and 2018-12-19

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107454, Oxygen, Dissolved	Region 3
Tequisquita Slough

LOE ID:

48887

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Water Board Staff assessed public submissions data for Tequisquita Slough to determine beneficial use support and results are as follows: 4 of 22 samples exceed the criterion for Oxygen, Dissolved.

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentration shall not be reduced below 7.0 mg/l at any time (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TSR - Tequisquita Slough at Shore Rd]

Temporal Representation:

Data was collected over the time period 2/13/2007-6/30/2010.

Environmental Conditions:

Central Coast Water Board Staff are not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107454, Oxygen, Dissolved	Region 3
Tequisquita Slough

LOE ID:

12070

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Tequisquita Slough to determine beneficial use support and results are as follows: 3 of 16 samples exceed the criterion for Oxygen, Dissolved.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Coast Basin, General Objective, Chapter III, Section II.A.2 General Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries states the following: For waters not mentioned by a specific beneficial use, dissolved oxygen concentration shall not be reduced below 5.0 mg/l at any time.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TES-Tequisquita Slough at Shore Road]

Temporal Representation:

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):


DECISION ID	107446	Region 3
Tequisquita Slough

Pollutant:	2,4,6-Trichlorophenol
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:	This decision was made by SWRCB staff.

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 107446, 2,4,6-Trichlorophenol	Region 3
Tequisquita Slough

LOE ID:

183576

Pollutant:

2,4,6-Trichlorophenol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 6 samples exceeded the water quality threshold for Trichlorophenol, 2,4,6-.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Human health risk associated with organism consumption is 6.5 ug/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 (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107449	Region 3
Tequisquita Slough

Pollutant:	2,4-Dichlorophenol
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:	This decision was made by SWRCB staff.

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 107449, 2,4-Dichlorophenol	Region 3
Tequisquita Slough

LOE ID:

163989

Pollutant:

2,4-Dichlorophenol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the water quality threshold for Dichlorophenol, 2,4-.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Human health risk associated with organism consumption is 790 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107450	Region 3
Tequisquita Slough

Pollutant:	2,4-Dimethylphenol
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:	This decision was made by SWRCB staff.

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 107450, 2,4-Dimethylphenol	Region 3
Tequisquita Slough

LOE ID:

164790

Pollutant:

2,4-Dimethylphenol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Human health risk associated with organism consumption is 2,300 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107452	Region 3
Tequisquita Slough

Pollutant:	2,4-Dinitrophenol
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:	This decision was made by SWRCB staff.

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 107452, 2,4-Dinitrophenol	Region 3
Tequisquita Slough

LOE ID:

165008

Pollutant:

2,4-Dinitrophenol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Dinitrophenol, 2,4-.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Human health risk associated with organism consumption is 14,000 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2017-04-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107458	Region 3
Tequisquita Slough

Pollutant:	2-Chlorophenol
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:	This decision was made by SWRCB staff.

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 107458, 2-Chlorophenol	Region 3
Tequisquita Slough

LOE ID:

161023

Pollutant:

2-Chlorophenol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Human health risk associated with organism consumption is 400 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107475	Region 3
Tequisquita Slough

Pollutant:	Aldicarb
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 107475, Aldicarb	Region 3
Tequisquita Slough

LOE ID:

157209

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Aldicarb.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2014-04-23

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107425	Region 3
Tequisquita Slough

Pollutant:	Atrazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the Clean Water Act (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. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of zero of four samples exceed the evaluation guideline for the warm freshwater habitat beneficial use. The readily available data and information are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 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. 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. A total of zero of four samples exceed the evaluation guideline for the warm freshwater habitat 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. 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 107425, Atrazine	Region 3
Tequisquita Slough

LOE ID:

158814

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 4 samples exceeded the water quality threshold for Atrazine.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of <1 ug/L for a nonvascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107441	Region 3
Tequisquita Slough

Pollutant:	Azinphos-methyl (Guthion)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	This decision was made by SWRCB staff.

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 107441, Azinphos-methyl (Guthion)	Region 3
Tequisquita Slough

LOE ID:

159036

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The Criterion Continuous Concentration for freshwater aquatic life is 0.01 ug/L (National Recommended Water Quality Criteria, EPA 2016)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-03-01

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107469	Region 3
Tequisquita Slough

Pollutant:	Bifenthrin
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 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 in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) List. One line of evidence is available in the administrative record to assess this pollutant. Zero of the three sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1 of the Listing Policy. Therefore, the use support rating is set to 'insufficient information'. 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. 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 three sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107469, Bifenthrin	Region 3
Tequisquita Slough

LOE ID:

151097

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and the results are as follows: 0 of the 3 samples exceeded the evaluation guideline for Bifenthrin .

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin from Amweg et al. (2005) and Amweg and Weston (2007).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2017-09-25

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107426	Region 3
Tequisquita Slough

Pollutant:	Cadmium
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:	This decision was made by SWRCB staff.

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 107426, Cadmium	Region 3
Tequisquita Slough

LOE ID:

159730

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Cadmium.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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 (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107427	Region 3
Tequisquita Slough

Pollutant:	Carbaryl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 107427, Carbaryl	Region 3
Tequisquita Slough

LOE ID:

160351

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The Criterion Continuous Concentration for freshwater aquatic life is 2.1 ug/L (National Recommended Water Quality Criteria, EPA 2016)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2014-04-23

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107428	Region 3
Tequisquita Slough

Pollutant:	Carbofuran
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 107428, Carbofuran	Region 3
Tequisquita Slough

LOE ID:

160443

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Carbofuran is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertibrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2014-04-23

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107429	Region 3
Tequisquita Slough

Pollutant:	Chlordane
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 107429, Chlordane	Region 3
Tequisquita Slough

LOE ID:

151784

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Chlordane from MacDonald et al., 2000a which states that the probable effect concentration for Chlordane is 17.6 ug/kg. (dw = Dry Weight)

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2010-05-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107431	Region 3
Tequisquita Slough

Pollutant:	Chlorpyrifos
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 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 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) List. Two lines of evidence are available in the administrative record to assess this pollutant. Zero out of four water samples exceeded the aquatic life evaluation guideline (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005). Zero out of four sediment samples exceeded the aquatic life evaluation guideline (Amweg and Weston, 2007). These sample sizes are 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 supported using table 3.1. 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. 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 water samples and zero of four sediment samples exceeded the water quality objectives. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107431, Chlorpyrifos	Region 3
Tequisquita Slough

LOE ID:

161950

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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005).

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2017-09-25 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107431, Chlorpyrifos	Region 3
Tequisquita Slough

LOE ID:

151908

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the evaluation guideline for Chlorpyrifos .

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

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:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107484	Region 3
Tequisquita Slough

Pollutant:	Clothianidin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	This decision was made by SWRCB staff.

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 107484, Clothianidin	Region 3
Tequisquita Slough

LOE ID:

162312

Pollutant:

Clothianidin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Clothianidin is the USEPA Aquatic Life Benchmark of 0.05 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2017-09-25 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107432	Region 3
Tequisquita Slough

Pollutant:	Copper
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 Clean Water Act (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. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of zero of seven samples exceed the water quality objective for the warm freshwater habitat beneficial use. These data are insufficient to determine the applicable beneficial use support rating with the power and confidence required by the Listing Policy. After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed 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. A total of zero of seven samples exceed the water quality objective for the warm freshwater habitat beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107432, Copper	Region 3
Tequisquita Slough

LOE ID:

163045

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 3.

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 (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107473	Region 3
Tequisquita Slough

Pollutant:	Cyanazine
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:	This decision was made by SWRCB staff.

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 107473, Cyanazine	Region 3
Tequisquita Slough

LOE ID:

163402

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for cyanazine is the EC50 of 4.8 ug/L for Navicula pelliculosa (freshwater diatom) (USEPA Office of Pesticide Programs Ecotoxicity database).

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107477	Region 3
Tequisquita Slough

Pollutant:	Cyfluthrin
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 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 in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) List. One line of evidence is available in the administrative record to assess this pollutant. Zero of the five sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1 of the Listing Policy. Therefore, the use support rating is set to 'insufficient information'. 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. 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 sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107477, Cyfluthrin	Region 3
Tequisquita Slough

LOE ID:

152147

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and the results are as follows: 0 of the 5 samples exceeded the evaluation guideline for Cyfluthrin, total .

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

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:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107479	Region 3
Tequisquita Slough

Pollutant:	Cyhalothrin, Lambda
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 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 in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) List. One line of evidence is available in the administrative record to assess this pollutant. Zero of the five sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1 of the Listing Policy. Therefore, the use support rating is set to 'insufficient information'. 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. 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 sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107479, Cyhalothrin, Lambda	Region 3
Tequisquita Slough

LOE ID:

152415

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

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:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2018-04-23

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107470	Region 3
Tequisquita Slough

Pollutant:	Cypermethrin
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 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 in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) List. One line of evidence is available in the administrative record to assess this pollutant. Zero of the five sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1 of the Listing Policy. Therefore, the use support rating is set to 'insufficient information'. 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. 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 sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107470, Cypermethrin	Region 3
Tequisquita Slough

LOE ID:

152837

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 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al. (2002).

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	130083	Region 3
Tequisquita Slough

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
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 section 303(d) List under section 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the 303(d) List. One line of evidence is available in the administrative record to assess this pollutant. One LOE summarizes sediment samples. Zero of one sediment sample exceeds the DDD evaluation guideline (MacDonald et al., 2000a) set to protect for aquatic life beneficial uses. 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. 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 sediment samples exceeded the evaluation guidelines set to protect aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 130083, DDD (Dichlorodiphenyldichloroethane)	Region 3
Tequisquita Slough

LOE ID:

152728

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Sum DDD from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDD is 28 ug/kg. (dw = Dry Weight)

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2010-05-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	130156	Region 3
Tequisquita Slough

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
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 section 303(d) List under section 3.1 and section 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the 303(d) List. One line of evidence is available in the administrative record to assess this pollutant. One LOE summarizes sediment samples. One of one sediment sample exceeds the DDE evaluation guideline (MacDonald et al., 2000a) set to protect for aquatic life beneficial uses. 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. 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. One of one sediment sample exceeded the evaluation guidelines, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 130156, DDE (Dichlorodiphenyldichloroethylene)	Region 3
Tequisquita Slough

LOE ID:

153123

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the evaluation guideline for DDE (Dichlorodiphenyldichloroethylene) .

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2010-05-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	129993	Region 3
Tequisquita Slough

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
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 section 303(d) List under section 3.1 and 3.6 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the 303(d) List. Two lines of evidence are available in the administrative record to assess this pollutant. Note that this decision combines the pollutant ‘DDT’ and ‘total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD).’ Two LOEs summarize sediment samples. Zero of one sediment sample exceeds the DDT evaluation guideline (MacDonald et al., 2000a) set to protect for aquatic life beneficial uses. Zero of one sediment sample exceeds the total DDT evaluation guideline (MacDonald et al., 2000a) set to protect for aquatic life beneficial uses. 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. 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 sediment samples exceeded the evaluation guidelines set to protect aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 129993, DDT (Dichlorodiphenyltrichloroethane)	Region 3
Tequisquita Slough

LOE ID:

156011

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Total DDTs from MacDonald et al., 2000a which states that the probable effect concentration for Total DDTs is 572 ug/kg. (dw = Dry Weight)

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2010-05-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 129993, DDT (Dichlorodiphenyltrichloroethane)	Region 3
Tequisquita Slough

LOE ID:

153151

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Sum DDT from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDT is 62.9 ug/kg. (dw = Dry Weight)

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2010-05-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107478	Region 3
Tequisquita Slough

Pollutant:	Deltamethrin
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 107478, Deltamethrin	Region 3
Tequisquita Slough

LOE ID:

153606

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 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

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:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2010-05-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107433	Region 3
Tequisquita Slough

Pollutant:	Diazinon
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 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of seven water samples exceed the aquatic life evaluation guideline (Finlayson, 2004). 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 supported using table 3.1. 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero samples exceed the evaluation guidelines. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107433, Diazinon	Region 3
Tequisquita Slough

LOE ID:

163661

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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107434	Region 3
Tequisquita Slough

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 107434, Dichlorvos	Region 3
Tequisquita Slough

LOE ID:

164431

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 RWB3 Cooperative Monitoring Program data for Tequisquita Slough 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 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

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

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR).

Temporal Representation:

Date for this waterbody was collected over the date range 2014-02-27 to 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107435	Region 3
Tequisquita Slough

Pollutant:	Dieldrin
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 107435, Dieldrin	Region 3
Tequisquita Slough

LOE ID:

153686

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Dieldrin from MacDonald et al., 2000a which states that the probable effect concentration for Dieldrin is 61.8 ug/kg dw. (dw = Dry Weight)

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2010-05-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107472	Region 3
Tequisquita Slough

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:	This pollutant is being considered for placement on the section 303(d) List under sections 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 seven water samples exceeded the USEPA aquatic life evaluation guideline. 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 supported using table 3.1. 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero samples exceed the evaluation guidelines. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107472, Dimethoate	Region 3
Tequisquita Slough

LOE ID:

164847

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 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

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

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107436	Region 3
Tequisquita Slough

Pollutant:	Dinitro-o-cresol
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:	This decision was made by SWRCB staff.

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 107436, Dinitro-o-cresol	Region 3
Tequisquita Slough

LOE ID:

165054

Pollutant:

Dinitro-o-cresol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Human health risk associated with organism consumption is 765 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107437	Region 3
Tequisquita Slough

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:	This decision was made by SWRCB staff.

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 107437, Disulfoton	Region 3
Tequisquita Slough

LOE ID:

165131

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

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

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107438	Region 3
Tequisquita Slough

Pollutant:	Diuron
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:	This decision was made by SWRCB staff.

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 107438, Diuron	Region 3
Tequisquita Slough

LOE ID:

165325

Pollutant:

Diuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of Diuron, 1.3 ug/L, is not exceeded more than once every three years on the average (Fojut et al., 2010).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: III. Diuron. Reviews of Environmental Contamination and Toxicology 216:105-141.

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107439	Region 3
Tequisquita Slough

Pollutant:	Endrin
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 107439, Endrin	Region 3
Tequisquita Slough

LOE ID:

153852

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Endrin from MacDonald et al., 2000a which states that the probable effect concentration for Endrin is 207 ug/kg. (dw = Dry Weight)

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2010-05-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107481	Region 3
Tequisquita Slough

Pollutant:	Esfenvalerate/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:	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 107481, Esfenvalerate/Fenvalerate	Region 3
Tequisquita Slough

LOE ID:

154158

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 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

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:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2010-05-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107480	Region 3
Tequisquita Slough

Pollutant:	Fenpropathrin
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 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 in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) List. One line of evidence is available in the administrative record to assess this pollutant. Zero of the five sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1 of the Listing Policy. Therefore, the use support rating is set to 'insufficient information'. 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. 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 sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107480, Fenpropathrin	Region 3
Tequisquita Slough

LOE ID:

154251

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 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for fenpropathrin is the median lethal concentration (LC50) of 1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1 ug/g is the geometric mean of LC50 values for fenpropathrin from Ding et al. ( 2011).

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2018-04-23

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107440	Region 3
Tequisquita Slough

Pollutant:	Glyphosate
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 Clean Water Act (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. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of zero of five samples exceed the evaluation guideline for the warm freshwater habitat beneficial use. The readily available data and information are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 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. 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. A total of zero of five samples exceed the evaluation guideline for the warm freshwater habitat 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. 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 107440, Glyphosate	Region 3
Tequisquita Slough

LOE ID:

166803

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Glyphosate is the USEPA Aquatic Life Benchmark of 11900 ug/L for a vascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-08-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107466	Region 3
Tequisquita Slough

Pollutant:	Imidacloprid
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:	This decision was made by SWRCB staff.

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 107466, Imidacloprid	Region 3
Tequisquita Slough

LOE ID:

167290

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 1 of 2 samples exceeded the water quality threshold for Imidacloprid.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2017-12-13 and 2018-03-01

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107442	Region 3
Tequisquita Slough

Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1. Under section 3.1 at least one line of evidence is necessary to assess listing status. One line of evidence are available in the administrative record to assess this pollutant. Zero of the 7 dissolved lead samples exceed the evaluation guideline for the aquatic life beneficial uses. 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 supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1. Therefore, the use support rating is set to 'insufficient information.' 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 samples exceed the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107442, Lead	Region 3
Tequisquita Slough

LOE ID:

167938

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 3.

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 (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107443	Region 3
Tequisquita Slough

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:	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 107443, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 3
Tequisquita Slough

LOE ID:

154481

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Lindane from MacDonald et al., 2000a which states that the probable effect concentration for Lindane is 4.99 ug/kg. (dw = Dry Weight)

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2010-05-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107444	Region 3
Tequisquita Slough

Pollutant:	Linuron
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 Clean Water Act (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. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of zero of four samples exceed the evaluation guideline for the warm freshwater habitat beneficial use. The readily available data and information are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 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. 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. A total of zero of four samples exceed the evaluation guideline for the warm freshwater habitat 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. 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 107444, Linuron	Region 3
Tequisquita Slough

LOE ID:

168246

Pollutant:

Linuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Linuron is the USEPA Aquatic Life Benchmark of 0.09 ug/L for a invertebrate (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107445	Region 3
Tequisquita Slough

Pollutant:	Malathion
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 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 four samples exceed the evaluation guideline (Faria et al., 2010) applied to protect aquatic life beneficial uses. 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. 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero samples exceeded the evaluation guidelines and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. The sample size is 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. 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 107445, Malathion	Region 3
Tequisquita Slough

LOE ID:

168738

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the four-day average concentration of malathion does not exceed 0.028 ug/L more than once every three years on the average (Faria et al., 2010).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-08-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107423	Region 3
Tequisquita Slough

Pollutant:	Methamidophos
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:	This decision was made by SWRCB staff.

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 107423, Methamidophos	Region 3
Tequisquita Slough

LOE ID:

169675

Pollutant:

Methamidophos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Methamifophos is the USEPA Aquatic Life Benchmark of 4.5 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2017-09-25 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107471	Region 3
Tequisquita Slough

Pollutant:	Methidathion
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 section 303(d) List under sections 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 seven water samples exceeded the USEPA aquatic life evaluation guideline. 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 supported using table 3.1. 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero samples exceed the evaluation guidelines. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107471, Methidathion	Region 3
Tequisquita Slough

LOE ID:

170002

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Methidathion is the USEPA Aquatic Life Benchmark of 0.66 ug/L for a invertebrate (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107467	Region 3
Tequisquita Slough

Pollutant:	Methiocarb
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 107467, Methiocarb	Region 3
Tequisquita Slough

LOE ID:

170171

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Methiocarb is the USEPA Aquatic Life Benchmark of 2.75 ug/L for a invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2014-04-23

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107468	Region 3
Tequisquita Slough

Pollutant:	Methomyl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 107468, Methomyl	Region 3
Tequisquita Slough

LOE ID:

170376

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Methomyl is the USEPA Aquatic Life Benchmark of 0.7 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2014-04-23

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107447	Region 3
Tequisquita Slough

Pollutant:	Nickel
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 Clean Water Act (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. A total of three lines of evidence are available in the administrative record to assess this pollutant. A total of zero of seven samples exceed the dissolved fraction water quality objective and zero of seven samples exceed the total fraction water quality objective for the commercial or recreational collection of fish, shellfish, or organisms beneficial use and zero of seven samples exceed the water quality objective for the warm freshwater habitat beneficial use. These data are insufficient to determine the applicable beneficial use support rating with the power and confidence required by the Listing Policy. After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed 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. A total of zero of seven samples exceed the dissolved fraction water quality objective and zero of seven samples exceed the total fraction water quality objective for the commercial or recreational collection of fish, shellfish, or organisms beneficial use and zero of seven samples exceed the water quality objective for the warm freshwater habitat beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107447, Nickel	Region 3
Tequisquita Slough

LOE ID:

170690

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Human health risk associated with organism consumption is 4.6 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107447, Nickel	Region 3
Tequisquita Slough

LOE ID:

170746

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 3.

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 (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107447, Nickel	Region 3
Tequisquita Slough

LOE ID:

170601

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Human health risk associated with organism consumption is 4.6 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107451	Region 3
Tequisquita Slough

Pollutant:	Organophosphate Pesticides
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 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 seven water samples exceeded the aquatic life evaluation guideline for additive effects of chlorpyrifos and diazinon (Bailey et al., 1997). 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. 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. 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 seven water samples exceeded the evaluation guideline, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. 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 107451, Organophosphate Pesticides	Region 3
Tequisquita Slough

LOE ID:

173836

Pollutant:

Organophosphate Pesticides

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for the protection of aquatic life from the additive effects of the organophophate pesticides chlorpyrifos and diazinon is one toxic unit equivalent. A toxic unit equivalent is equal to the sum of chlorpyrifos and diazinon from a single sample, each having their reported concentration divided their respective evaluation guideline prior to being summed. If this results in a value greater than one, the sample is considered to be in exceedance of the water quality standard. (Bailey et al., 1997).

Guideline Reference:

Joint acute toxicity of Diazinon and Chlorpyrifos to Ceriodaphnia dubia.

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107453	Region 3
Tequisquita Slough

Pollutant:	Oxamyl (Vydate)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 107453, Oxamyl (Vydate)	Region 3
Tequisquita Slough

LOE ID:

173961

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Oxamyl is the USEPA Aquatic Life Benchmark of 27 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2014-04-23

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107482	Region 3
Tequisquita Slough

Pollutant:	Paraquat
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 Clean Water Act (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. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of zero of one sample exceeds the evaluation guideline for the warm freshwater habitat beneficial use. The readily available data and information are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 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. 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. A total of zero of one sample exceeds the evaluation guideline for the warm freshwater habitat 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. 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 107482, Paraquat	Region 3
Tequisquita Slough

LOE ID:

176379

Pollutant:

Paraquat

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality threshold for Paraquat. Although a total of 2 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Paraquat is the USEPA Aquatic Life Benchmark of 0.396 ug/L for a nonvascular plant (acute) for Paraquat dichloride.

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR).

Temporal Representation:

Data for this waterbody was collected over the date range 2014-08-27 to 2017-12-13

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107455	Region 3
Tequisquita Slough

Pollutant:	Pentachlorophenol (PCP)
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:	This decision was made by SWRCB staff.

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 107455, Pentachlorophenol (PCP)	Region 3
Tequisquita Slough

LOE ID:

176866

Pollutant:

Pentachlorophenol (PCP)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Pentachlorophenol criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is pH dependent. The criteria has a value of 15 ug/L when based on a default pH of 7.8. (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 107455, Pentachlorophenol (PCP)	Region 3
Tequisquita Slough

LOE ID:

176894

Pollutant:

Pentachlorophenol (PCP)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Human health risk associated with organism consumption is 8.2 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107483	Region 3
Tequisquita Slough

Pollutant:	Permethrin
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 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 in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) List. One line of evidence is available in the administrative record to assess this pollutant. Zero of the three sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1 of the Listing Policy. Therefore, the use support rating is set to 'insufficient information'. 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. 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 three sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107483, Permethrin	Region 3
Tequisquita Slough

LOE ID:

155470

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 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

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:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2017-09-25

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107457	Region 3
Tequisquita Slough

Pollutant:	Phenol
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:	This decision was made by SWRCB staff.

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 107457, Phenol	Region 3
Tequisquita Slough

LOE ID:

179997

Pollutant:

Phenol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Human health risk associated with organism consumption is 4,600,000 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107474	Region 3
Tequisquita Slough

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:	This pollutant is being considered for placement on the 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of seven water samples exceeded the USEPA aquatic life evaluation guideline. 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 supported using table 3.1. 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero samples exceed the evaluation guidelines. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107474, Phorate	Region 3
Tequisquita Slough

LOE ID:

180173

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 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for a invertebrate (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107476	Region 3
Tequisquita Slough

Pollutant:	Phosmet
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 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. One line of evidence is available in the administrative record to assess this pollutant. Zero of six water samples exceed the USEPA aquatic life evaluation guideline. 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 supported using table 3.1. 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. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero samples exceed the evaluation guidelines. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) List. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107476, Phosmet	Region 3
Tequisquita Slough

LOE ID:

180703

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Phosmet is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107465	Region 3
Tequisquita Slough

Pollutant:	Pyrethroids
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 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 in sediment. The pollutant concentration in sediment must be associated with toxicity to result in addition of the pollutant to the Section 303(d) List. One lines of evidence is available in the administrative record to assess this pollutant. Zero of the six sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses. A minimum of 16 samples is needed to determine if a beneficial use is supported and a minimum of two exceedances is needed to determine if beneficial uses are not supported using table 3.1 of the Listing Policy. Therefore, the use support rating is set to 'insufficient information'. 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. 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 six sediment samples exceed the evaluation guideline applied to protect for aquatic life beneficial uses and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107465, Pyrethroids	Region 3
Tequisquita Slough

LOE ID:

155634

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the evaluation guideline for Pyrethroids .

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

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, Central Coast Basin, Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit. Individual pyrethroid concentrations in sediment were normalized to organic carbon content, divided by the respective LC50 and then summed. A sum over over one toxic unit is an exceedance of the evaluation guideline (Amweg et al. 2006).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

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

Guideline Reference:

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

Guideline Reference:

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

Guideline Reference:

Pyrethroid insecticides and sediment toxicity in urban creeks from California and Tennessee. Environmental Science and Technology, 40(5): 1700-1706

Guideline Reference:

Compilation of freshwater OC-normalized sediment toxicity data for pyrethroids

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 305TSR.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-05-26 to 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107460	Region 3
Tequisquita Slough

Pollutant:	Simazine
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 Clean Water Act (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. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of zero of four samples exceed the evaluation guideline for the warm freshwater habitat beneficial use. The readily available data and information are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 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. 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. A total of zero of four samples exceed the evaluation guideline for the warm freshwater habitat 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. 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 107460, Simazine	Region 3
Tequisquita Slough

LOE ID:

181893

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107485	Region 3
Tequisquita Slough

Pollutant:	Thiamethoxam
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 107485, Thiamethoxam	Region 3
Tequisquita Slough

LOE ID:

156449

Pollutant:

Thiamethoxam

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall reach concentrations that adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

The evaluation guideline for Thiamethoxam is the USEPA Aquatic Life Benchmark of 0.74 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2017-12-13 and 2017-12-13

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107462	Region 3
Tequisquita Slough

Pollutant:	Trifluralin
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 Clean Water Act (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. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of zero of four samples exceed the evaluation guideline for the warm freshwater habitat beneficial use. The readily available data and information are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 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. 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. A total of zero of four samples exceed the evaluation guideline for the warm freshwater habitat 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. 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 107462, Trifluralin	Region 3
Tequisquita Slough

LOE ID:

183561

Pollutant:

Trifluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

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 3.

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, Central Coast Basin, General Objective Chapter III, Section II.A.2 Objectives for all Inland Surface Waters, Enclosed Bays and Estuaries).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

UC Davis Aquatic Life Criteria: Aquatic life should not be affected unacceptably if the four-day average concentration of Trifluralin does not exceed 0.33 ug/L in the water column more than once every three years on average (Bower, et al. 2017).

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-04-23 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107464	Region 3
Tequisquita Slough

Pollutant:	Zinc
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 Clean Water Act (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. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of zero of seven samples exceed the water quality objective for the warm freshwater habitat beneficial use. These data are insufficient to determine the applicable beneficial use support rating with the power and confidence required by the Listing Policy. After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed 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. A total of zero of seven samples exceed the water quality objective for the warm freshwater habitat beneficial use. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107464, Zinc	Region 3
Tequisquita Slough

LOE ID:

156699

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 3.

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 (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107459	Region 3
Tequisquita Slough

Pollutant:	Selenium
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	No Source Analysis Available
Expected TMDL Completion Date:	2035
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the Clean Water Act (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. A total of one line of evidence is available in the administrative record to assess this pollutant. A total of two of six samples exceed the water quality objective for the warm freshwater habitat beneficial use. After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed 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. A total of two of six samples exceed the water quality objective for the warm freshwater habitat beneficial use. This exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 107459, Selenium	Region 3
Tequisquita Slough

LOE ID:

181211

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 2 of 6 samples exceeded the water quality threshold for Selenium.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The criterion continuous concentration 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 (305TSR)

Temporal Representation:

The samples were collected between the dates of 2014-02-27 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	128218	Region 3
Tequisquita Slough

Pollutant:	Nitrate
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	Agriculture \| Domestic Animals/Livestock \| Natural Sources
TMDL Name:	Pajaro River Watershed Nutrients
TMDL Project Code:	999
Date TMDL Approved by USEPA:	10/06/2016
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. The Aquatic Life beneficial uses are not supported. Since the 2010 Integrated Report assessment cycle, Central Coast Water Board staff assessed nitrate data using an evaluation guideline (Central Coast Region Technical Report, 2010) used to interpret the narrative water quality objective for biostimulatory substances, set to protect Cold and Warm Freshwater Habitat beneficial uses. Sixty-one of the 92 nitrate/nitrite samples exceed this evaluation guideline. In addition, and in accordance with section 3.11 of the Listing Policy, the following evidence supports the conclusion that nitrate contributes to or causes a bio-stimulatory response in this waterbody. 1) Dissolved oxygen for this water body ranged from 1.6 mg/L to 18.9 mg/L, exceeding both the water quality objective of 7.0 mg/L and the upper dissolved oxygen screening level of 13.0 mg/L (R3 NNE Technical Report, 2010). 2) Water column chlorophyll a concentrations in this water body were measured above 199 ug/L on multiple occasions exceeding the screening threshold of 15 ug/L (R3 NNE Technical Report, 2010). 3) Both photos and field observations document nuisance algal mats and scum. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. [NUMBER] of [NUMBER] samples exceed the [OBJECTIVE/GUIDELINE/CRITERIA] and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. 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. Sixty-one of the 92 nitrate/nitrite samples exceed this evaluation guideline and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. In addition, and in accordance with section 3.11 of the Listing Policy, there is evidence that supports the conclusion that nitrate contributes to or causes a bio-stimulatory response in this waterbody. 4. The Pajaro River Watershed Nutrient TMDL has been approved by the USEPA. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:	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. Sixty-one of the 92 nitrate/nitrite samples exceed this evaluation guideline and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. In addition, and in accordance with section 3.11 of the Listing Policy, there is evidence that supports the conclusion that nitrate contributes to or causes a bio-stimulatory response in this waterbody. 4. The Pajaro River Watershed Nutrient TMDL has been approved by the USEPA. 5. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 128218, Nitrate	Region 3
Tequisquita Slough

LOE ID:

171835

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate 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:

Water Board staff assessed RWB3 Cooperative Monitoring Program data for Tequisquita Slough to determine beneficial use support and results are as follows: 58 of 89 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 3.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses (Water Quality Control Plan, Central Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Technical approach to develop nutrient numeric endpoints for California, Tetra Tech, June 2006. The Central Coast Region numeric target for maximum nitrate concentration is based on the Tetra Tech NNE (Nutrient Numeric Endpoint) Model and CCAMP data for 193 sites, monitored monthly for at least 1 year between January 1998 and December 2006. The model numeric target for aquatic life habitats in the Central Coast Region is 1.0 mg/L Nitrate as N.

Guideline Reference:

Central Coast RegionTechnical Paper: Interpreting Narrative Objectives for Biostimulatory Substances for California Central Coast Waters. This method uses the Technical Approach for Developing California Nutrient Numeric Endpoints.

Spatial Representation:

The samples were collected at 1 monitoring site (305TSR)

Temporal Representation:

The samples were collected between the dates of 2010-04-26 and 2018-09-26

Environmental Conditions:

QAPP Information:

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6.

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6

Line of Evidence (LOE) for Decision ID 128218, Nitrate	Region 3
Tequisquita Slough

LOE ID:

149444

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate 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:

Water Board staff assessed Surface Water Monitoring Project data for Tequisquita Slough to determine beneficial use support and results are as follows: 3 of 3 samples exceeded the water quality standard for Nitrate + Nitrite as N.

Data Reference:

CMP water quality data 10/17/2018--12/20/2018.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data were collected from 1 station. Station Code(s): 305TSR

Temporal Representation:

Data for this waterbody were collected between 2018-10-24 and 2018-12-19

Environmental Conditions:

QAPP Information:

Data was collected verified in accordance with the Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program,

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring for the Region 3 Conditional Ag Waiver Cooperative Monitoring Program, Revision 6


DECISION ID	107430	Region 3
Tequisquita Slough

Pollutant:	Chlorophyll-a
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2018)
Revision Status	Original
Sources:	No Source Analysis Available
Expected TMDL Completion Date:	2035
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	No new data were assessed for the 2020 listing cycle. 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. Three lines of evidence are available in the administrative record to assess this pollutant. Nine of the 36 samples exceed the evaluation guideline (North Carolina Administrative code, Title 15A) used to interpret the narrative water quality objective for bio-stimulation risk and aquatic life beneficial uses. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Nine of the 36 samples exceed the evaluation guideline and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	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 107430, Chlorophyll-a	Region 3
Tequisquita Slough

LOE ID:

9366

Pollutant:

Chlorophyll-a

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Central Coast Regional Board Staff assessed CCAMP Pajaro (Pajaro) data for Tequisquita Slough to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Chlorophyll a.

Data Reference:

Final Data File used for assessment: CCAMP Water Quality Data_file1

Final Data File used for assessment: CCAMP Water Quality Data_file2

Final Data File used for assessment: CCAMP Water Quality Data_file3

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) - Central Coast Region (Region 3)

Objective/Criterion Reference:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Objective/Criterion Reference:

Water quality standards table

Evaluation Guideline:

North Carolina Administrative code (NCAC), Title 15A - Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife). Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.

Guideline Reference:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Guideline Reference:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Spatial Representation:

Data for this line of evidence for Tequisquita Slough was collected at 1 monitoring site [ 305TES-Tequisquita Slough at Shore Road]

Temporal Representation:

Data was collected over the time period 2/19/1998-12/16/1998. Pajaro watershed is one of five annual rotation areas that are monitored for conventional pollutants by CCAMP staff monthly for one year.

Environmental Conditions:

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

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 107430, Chlorophyll-a	Region 3
Tequisquita Slough

LOE ID:

48876

Pollutant:

Chlorophyll-a

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:

Central Coast Water Board Staff assessed public submissions data for Tequisquita Slough to determine beneficial use support and results are as follows: 9 of 21 samples exceed the criterion for Chlorophyll a.

Data Reference:

Data from Region 3 Conditional Waiver Cooperative Monitoring Program, Jan. 2007-Jun. 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the Central Coastal Basin

Evaluation Guideline:

Guideline Reference:

North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards

Guideline Reference:

Water quality standards table