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

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)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541MER535 (San Luis Drain @ Terminus).

Temporal Representation:

The samples were collected between the dates of 1996-11-26 and 2001-11-29

Environmental Conditions:

QAPP Information:

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)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159984, Chloride	Region 5
San Luis Drain

LOE ID:

330946

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the upper limit of the range for Chloride. Additionally, 0 of the 2 samples fall within the range, and 0 of 2 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541SLDGCR (San Luis Drain - Gun Club Road).

Temporal Representation:

The samples were collected between the dates of 2013-12-10 and 2014-02-27

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 159984, Chloride	Region 5
San Luis Drain

LOE ID:

345848

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP BDAT data for San Luis Drain to determine beneficial use support and results are as follows: 2 of 3 samples exceeded the upper limit of the range for Chloride. Additionally, 1 of the 3 samples fall within the range, and 0 of 3 samples fall below the threshold.

Data 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)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541MER562 (Inflow to San Luis Drain).

Temporal Representation:

The samples were collected between the dates of 1996-09-26 and 2000-04-26

Environmental Conditions:

QAPP Information:

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)

QAPP Information Reference(s):


DECISION ID	119780	Region 5
San Luis Drain

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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119780, Chlorpyrifos	Region 5
San Luis Drain

LOE ID:

187448

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

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 (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-15 to 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119807	Region 5
San Luis Drain

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

Regional Board Conclusion:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119807, Chromium	Region 5
San Luis Drain

LOE ID:

187479

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for total chromium incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.05 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2012-06-06 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	159985	Region 5
San Luis Drain

Pollutant:	Copper
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollution

Regional Board Conclusion:	Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159985, Copper	Region 5
San Luis Drain

LOE ID:

331056

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Copper.

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary Maximum Contaminant Level for copper incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 1.0 mg/L assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541SLDGCR (San Luis Drain - Gun Club Road).

Temporal Representation:

The samples were collected between the dates of 2018-01-30 and 2020-01-03

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 159985, Copper	Region 5
San Luis Drain

LOE ID:

187718

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Copper.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

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 (541MER535)

Temporal Representation:

The samples were collected between the dates of 2012-06-06 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119809	Region 5
San Luis Drain

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

Regional Board Conclusion:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119809, Coumaphos	Region 5
San Luis Drain

LOE ID:

187680

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Coumaphos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for chronic toxicity in invertebrates (7 day average).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-15 to 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119808	Region 5
San Luis Drain

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

Regional Board Conclusion:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119808, Demeton	Region 5
San Luis Drain

LOE ID:

188289

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Demeton, Total. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria toxicity threshold for demeton for freshwater aquatic life protection is 0.1 ug/l (4 day average)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-15 to 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119782	Region 5
San Luis Drain

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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119782, Diazinon	Region 5
San Luis Drain

LOE ID:

188470

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L (4 day average)(Finlayson, 2004).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2013-08-15 and 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119783	Region 5
San Luis Drain

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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119783, Dichlorvos	Region 5
San Luis Drain

LOE ID:

188790

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

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 for the Sacramento and San Joaquin River Basins).

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-15 to 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119800	Region 5
San Luis Drain

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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119800, Dimethoate	Region 5
San Luis Drain

LOE ID:

188921

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2013-08-15 and 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119784	Region 5
San Luis Drain

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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119784, Disulfoton	Region 5
San Luis Drain

LOE ID:

189216

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for chronic toxicity in invertebrates (7 day average).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-15 to 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119785	Region 5
San Luis Drain

Pollutant:	EPTC (Eptam, s-ethyl dipropylthiocarbamate)
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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119785, EPTC (Eptam, s-ethyl dipropylthiocarbamate)	Region 5
San Luis Drain

LOE ID:

189735

Pollutant:

EPTC (Eptam, s-ethyl dipropylthiocarbamate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for EPTC (Eptam, s-ethyl dipropylthiocarbamate) is the USEPA Aquatic Life Benchmark of 40 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2013-08-15 and 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119798	Region 5
San Luis Drain

Pollutant:	Ethion
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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119798, Ethion	Region 5
San Luis Drain

LOE ID:

189939

Pollutant:

Ethion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria toxicity threshold for ethion for freshwater aquatic life protection is 0.02 ug/l

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-15 to 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119801	Region 5
San Luis Drain

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

Regional Board Conclusion:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119801, Ethoprop	Region 5
San Luis Drain

LOE ID:

189685

Pollutant:

Ethoprop

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Ethoprop is the USEPA Aquatic Life Benchmark of 0.8 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2013-08-15 and 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119799	Region 5
San Luis Drain

Pollutant:	Ethyl p-nitrophenyl (EPN)
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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119799, Ethyl p-nitrophenyl (EPN)	Region 5
San Luis Drain

LOE ID:

189718

Pollutant:

Ethyl p-nitrophenyl (EPN)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The Basin Plan states: \Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide...\" The evaluation guideline for EPN, 0.68 ug/L, is one-tenth of the median lethal concentration (LC50 = 6.8 ug/L) for Gammarus fasciatus (Scud); USEPA Office of Pesticide Programs Ecotoxicity database."

Guideline Reference:

OPP Pesticide Ecotoxicity Database.

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2013-08-15 and 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119806	Region 5
San Luis Drain

Pollutant:	Fenthion
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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119806, Fenthion	Region 5
San Luis Drain

LOE ID:

189948

Pollutant:

Fenthion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenthion. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Fenthion is the USEPA Aquatic Life Benchmark of 0.013 ug/L for chronic toxicity in invertebrates (7 day average).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-15 to 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	159987	Region 5
San Luis Drain

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:	Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159987, Glyphosate	Region 5
San Luis Drain

LOE ID:

331601

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 0 of 11 samples exceeded the water quality threshold for Glyphosate.

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Glyphosate incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.7 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541SLDGCR (San Luis Drain - Gun Club Road).

Temporal Representation:

The samples were collected between the dates of 2019-01-24 and 2021-03-16

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652


DECISION ID	127061	Region 5
San Luis Drain

Pollutant:	Indicator Bacteria
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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 127061, Indicator Bacteria	Region 5
San Luis Drain

LOE ID:

194700

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for San Luis Drain to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective applicable to all waters, except Lake Tahoe, where the salinity is less than 10 parts per thousand (ppth) 95 percent or more of the time is a STATISTICAL THRESHOLD VALUE (STV) of 320 cfu/100 mL not to be exceeded more than 10 percent of the time (calculated monthly).

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 541MER535

Temporal Representation:

The samples were collected between the days of 2010-12-14 and 2011-05-24 .

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 127061, Indicator Bacteria	Region 5
San Luis Drain

LOE ID:

194474

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for San Luis Drain to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 541MER535

Temporal Representation:

The samples were collected between the days of 2012-06-06 and 2012-06-06 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	159988	Region 5
San Luis Drain

Pollutant:	Lead
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159988, Lead	Region 5
San Luis Drain

LOE ID:

331720

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for lead incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.015 mg/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541SLDGCR (San Luis Drain - Gun Club Road).

Temporal Representation:

The samples were collected between the dates of 2013-11-04 and 2014-02-27

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 159988, Lead	Region 5
San Luis Drain

LOE ID:

190906

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

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 (541MER535)

Temporal Representation:

The samples were collected between the dates of 2012-06-06 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 159988, Lead	Region 5
San Luis Drain

LOE ID:

190750

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: At a minimum, water designated for use as MUN shall not contain lead in excess of 0.015 mg/l.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2012-06-06 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119788	Region 5
San Luis Drain

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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119788, Malathion	Region 5
San Luis Drain

LOE ID:

191153

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of malathion does not exceed 0.028 ug/L (UC Davis Aquatic Life Criteria).

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 (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-15 to 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	165435	Region 5
San Luis Drain

Pollutant:	Mercury
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 165435, Mercury	Region 5
San Luis Drain

LOE ID:

191028

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Mercury. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The mercury criteria for the protection of human health from the consumption of water and organisms is 0.050 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2012-06-06 to 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 165435, Mercury	Region 5
San Luis Drain

LOE ID:

190983

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2012-06-06 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 165435, Mercury	Region 5
San Luis Drain

LOE ID:

331776

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Mercury. Although a total of 4 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The mercury criteria for the protection of human health from the consumption of water and organisms is 0.050 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541SLDGCR).

Temporal Representation:

The samples were collected between the dates of 2013-11-04 and 2014-02-27

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652


DECISION ID	119789	Region 5
San Luis Drain

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

Regional Board Conclusion:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119789, Methyl Parathion	Region 5
San Luis Drain

LOE ID:

192987

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The California Department of Fish and Game instantaneous aquatic life criterion for Methyl Parathion is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System. California Department of Fish and Game. Environmental Services Division. Administrative Report 92-1

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-15 to 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119790	Region 5
San Luis Drain

Pollutant:	Molybdenum
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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

Line of Evidence (LOE) for Decision ID 119790, Molybdenum	Region 5
San Luis Drain

LOE ID:

191927

Pollutant:

Molybdenum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 37 of 37 samples exceeded the water quality threshold for Molybdenum.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Evaluation Guideline:

Water Quality for Agriculture, published by the Food and Agriculture Organization of the United Nations in 1985, contains criteria protective of various agricultural uses of water. These criteria were used to translate narrative water quality objectives for chemical constituents that prohibit chemicals in concentrations that would impair agricultural uses of water. A 10 ug/L criteria is the recommended maximum concentration of molybdenum in irrigation water.

Guideline Reference:

Water Quality for Agriculture, Food and Agriculture Organization of the United Nations - Irrigation and Drainage Paper No. 29, Rev 1, Rome (1985)

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2010-10-05 and 2013-09-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	159989	Region 5
San Luis Drain

Pollutant:	Nickel
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, determined to be inaccurate, and removed. Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159989, Nickel	Region 5
San Luis Drain

LOE ID:

331856

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for nickel incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.1 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541SLDGCR (San Luis Drain - Gun Club Road).

Temporal Representation:

The samples were collected between the dates of 2013-11-04 and 2014-02-27

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 159989, Nickel	Region 5
San Luis Drain

LOE ID:

191791

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for nickel incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.1 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2012-06-06 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 159989, Nickel	Region 5
San Luis Drain

LOE ID:

191907

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

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 (541MER535)

Temporal Representation:

The samples were collected between the dates of 2012-06-06 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	169914	Region 5
San Luis Drain

Pollutant:	Nitrogen, Nitrate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 169914, Nitrogen, Nitrate	Region 5
San Luis Drain

LOE ID:

192180

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 0 of 31 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Nitrate as N incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2012-01-05 and 2013-09-25

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 169914, Nitrogen, Nitrate	Region 5
San Luis Drain

LOE ID:

192233

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 5 of 13 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Nitrate as N incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2011-06-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 169914, Nitrogen, Nitrate	Region 5
San Luis Drain

LOE ID:

192075

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 3 of 12 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Nitrate as N incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2011-05-31 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 169914, Nitrogen, Nitrate	Region 5
San Luis Drain

LOE ID:

331947

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Primary California Primary Maximum Contaminant Level for Nitrate as N incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541MER535 (San Luis Drain @ Terminus).

Temporal Representation:

The samples were collected between the dates of 2010-11-02 and 2010-11-02

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 169914, Nitrogen, Nitrate	Region 5
San Luis Drain

LOE ID:

331949

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 0 of 44 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Primary California Primary Maximum Contaminant Level for Nitrate as N incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541SLDGCR (San Luis Drain - Gun Club Road).

Temporal Representation:

The samples were collected between the dates of 2017-01-26 and 2021-12-28

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 169914, Nitrogen, Nitrate	Region 5
San Luis Drain

LOE ID:

331960

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 0 of 10 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Primary California Primary Maximum Contaminant Level for Nitrate as N incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541SLDGCR (San Luis Drain - Gun Club Road).

Temporal Representation:

The samples were collected between the dates of 2013-11-04 and 2014-12-16

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652


DECISION ID	128265	Region 5
San Luis Drain

Pollutant:	Nitrogen, Nitrite
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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 128265, Nitrogen, Nitrite	Region 5
San Luis Drain

LOE ID:

192657

Pollutant:

Nitrogen, Nitrite

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Nitrite as N incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 1000 ug/L .

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2012-06-06 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	123631	Region 5
San Luis Drain

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

Regional Board Conclusion:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 123631, Oxygen, Dissolved	Region 5
San Luis Drain

LOE ID:

208697

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

122

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 5 of 122 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as SPWN is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2011-05-31 and 2013-09-25

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 123631, Oxygen, Dissolved	Region 5
San Luis Drain

LOE ID:

209046

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for San Luis Drain to determine beneficial use support and results are as follows: 0 of 45 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as COLD is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2011-06-28

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 123631, Oxygen, Dissolved	Region 5
San Luis Drain

LOE ID:

208798

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:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as SPWN is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2011-06-28

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 123631, Oxygen, Dissolved	Region 5
San Luis Drain

LOE ID:

209196

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

122

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The minimum dissolved oxygen concentration for waters designated as COLD is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2011-05-31 and 2013-09-25

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119792	Region 5
San Luis Drain

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

Regional Board Conclusion:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119792, Parathion	Region 5
San Luis Drain

LOE ID:

192775

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA recommended freshwater aquatic life ambient water quality chronic criteria for Parathion is 0.013 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-15 to 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119802	Region 5
San Luis Drain

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

Regional Board Conclusion:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119802, Pendimethalin	Region 5
San Luis Drain

LOE ID:

193008

Pollutant:

Pendimethalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Pendimethalin is the USEPA Aquatic Life Benchmark of 5.2 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2013-08-15 and 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119803	Region 5
San Luis Drain

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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119803, Phorate	Region 5
San Luis Drain

LOE ID:

193019

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Phorate is the USEPA Aquatic Life Benchmark of 0.21 ug/L for a invertebrate (acute).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2013-08-15 and 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	164116	Region 5
San Luis Drain

Pollutant:	Selenium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 164116, Selenium	Region 5
San Luis Drain

LOE ID:

344286

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

301

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Waterboard staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 31 of 301 samples exceeded the water quality standard for Selenium

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for selenium in this water body is 0.02 mg/L (as a 7-day average).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541SLDGCR)

Temporal Representation:

The samples were collected between the dates of 2013-10-21 and 2021-12-31.

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 164116, Selenium	Region 5
San Luis Drain

LOE ID:

344270

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Waterboard staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 17 of 17 samples exceeded the water quality standard for Selenium

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for selenium in this water body is 0.002 mg/L (as a monthly average).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER562)

Temporal Representation:

The samples were collected between the dates of 2020-01-07 and 2021-12-31.

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 164116, Selenium	Region 5
San Luis Drain

LOE ID:

344269

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Waterboard staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality standard for Selenium

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for selenium in this water body is 0.002 mg/L (as a monthly average).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2010-08-30 and 2010-08-30.

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 164116, Selenium	Region 5
San Luis Drain

LOE ID:

344285

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Waterboard staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 2 of 65 samples exceeded the water quality standard for Selenium

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for selenium in this water body is 0.02 mg/L (as a 7-day average).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER562)

Temporal Representation:

The samples were collected between the dates of 2020-01-13 and 2021-12-31.

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 164116, Selenium	Region 5
San Luis Drain

LOE ID:

344284

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for selenium in this water body is 0.02 mg/L (as a 7-day average).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2010-08-30 and 2010-08-30.

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 164116, Selenium	Region 5
San Luis Drain

LOE ID:

344271

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Waterboard staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 80 of 89 samples exceeded the water quality standard for Selenium

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Basin Plan objective for selenium in this water body is 0.002 mg/L (as a monthly average).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541SLDGCR)

Temporal Representation:

The samples were collected between the dates of 2013-10-21 and 2021-12-31.

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 164116, Selenium	Region 5
San Luis Drain

LOE ID:

193551

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 26 of 26 samples exceeded the water quality threshold for Selenium.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2011-02-15 and 2013-09-25

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 164116, Selenium	Region 5
San Luis Drain

LOE ID:

193335

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 6 of 21 samples exceeded the water quality threshold for Selenium.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for selenium incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.05 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2011-02-15 and 2013-09-25

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	169906	Region 5
San Luis Drain

Pollutant:	Specific Conductivity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 169906, Specific Conductivity	Region 5
San Luis Drain

LOE ID:

346542

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB5 Monitoring data for San Luis Drain to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 2 samples fall within the range, and 0 of 2 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL that is incorporated by reference into the Water Quality Control Plan for the Sacramento and San Joaquin River Basins specifies a range for specific conductance of 900-1600 uS/cm assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541MER535 (San Luis Drain @ Terminus).

Temporal Representation:

The samples were collected between the dates of 2010-12-28 and 2011-06-28

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 169906, Specific Conductivity	Region 5
San Luis Drain

LOE ID:

346472

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 4 of 4 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 4 samples fall within the range, and 0 of 4 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

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: 541MER562 (Inflow to San Luis Drain).

Temporal Representation:

The samples were collected between the dates of 2010-12-31 and 2013-12-29

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 169906, Specific Conductivity	Region 5
San Luis Drain

LOE ID:

345929

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows data for San Luis Drain to determine beneficial use support and results are as follows: 11 of 11 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 11 samples fall within the range, and 0 of 11 samples fall below the threshold.

Data Reference:

Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER535 (MER535).

Temporal Representation:

The samples were collected between the dates of 1996-12-27 and 2006-10-26

Environmental Conditions:

QAPP Information:

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)

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 169906, Specific Conductivity	Region 5
San Luis Drain

LOE ID:

332817

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 3 of 3 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 3 samples fall within the range, and 0 of 3 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541MER562 (Inflow to San Luis Drain).

Temporal Representation:

The samples were collected between the dates of 2010-08-30 and 2021-12-31

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 169906, Specific Conductivity	Region 5
San Luis Drain

LOE ID:

332831

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 9 of 9 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 9 samples fall within the range, and 0 of 9 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541SLDGCR (San Luis Drain - Gun Club Road).

Temporal Representation:

The samples were collected between the dates of 2013-12-27 and 2021-12-28

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 169906, Specific Conductivity	Region 5
San Luis Drain

LOE ID:

346422

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

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: 541MER535 (San Luis Drain @ Terminus).

Temporal Representation:

The samples were collected between the dates of 2010-12-31 and 2013-09-25

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 169906, Specific Conductivity	Region 5
San Luis Drain

LOE ID:

332738

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541MER535 (San Luis Drain @ Terminus).

Temporal Representation:

The samples were collected between the dates of 2010-08-30 and 2021-12-31

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 169906, Specific Conductivity	Region 5
San Luis Drain

LOE ID:

346013

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed RWB5S SJR Trends FY0708 FY0809 data for San Luis Drain to determine beneficial use support and results are as follows: 3 of 3 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 0 of the 3 samples fall within the range, and 0 of 3 samples fall below the threshold.

Data Reference:

RWB5S SJR Trends FY0708 FY0809

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541MER535 (San Luis Drain @ Terminus).

Temporal Representation:

The samples were collected between the dates of 2007-12-27 and 2009-06-25

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	159990	Region 5
San Luis Drain

Pollutant:	Sulfates
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159990, Sulfates	Region 5
San Luis Drain

LOE ID:

332844

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 2 of 2 samples exceeded the upper limit of the range for Sulfate. Additionally, 0 of the 2 samples fall within the range, and 0 of 2 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL that is incorporated by reference into the Water Quality Control Plan for the Sacramento and San Joaquin River Basins specifies a range for sulfate of 250-500 mg/L assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541SLDGCR (San Luis Drain - Gun Club Road).

Temporal Representation:

The samples were collected between the dates of 2013-12-10 and 2014-02-27

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 159990, Sulfates	Region 5
San Luis Drain

LOE ID:

346692

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the upper limit of the range for Sulfate. Additionally, 0 of the 1 samples fall within the range, and 0 of 1 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

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: 541MER535 (San Luis Drain @ Terminus).

Temporal Representation:

The samples were collected between the dates of 2012-06-06 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	131157	Region 5
San Luis Drain

Pollutant:	Temperature, water
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:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 131157, Temperature, water	Region 5
San Luis Drain

LOE ID:

230440

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 SWAMP RWB5 Monitoring data for San Luis Drain to determine beneficial use support and results are as follows: 9 of 43 samples exceeded the water quality threshold for Temperature.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses (Sacramento-San Joaquin River Basin Plans.

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2011-06-28

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 131157, Temperature, water	Region 5
San Luis Drain

LOE ID:

230992

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 44 of 93 samples exceeded the water quality threshold for Temperature.

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2011-05-31 and 2013-09-25

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 131157, Temperature, water	Region 5
San Luis Drain

LOE ID:

230996

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Fish Migration

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2011-05-31 and 2013-09-25

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 131157, Temperature, water	Region 5
San Luis Drain

LOE ID:

230437

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Fish Migration

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2011-06-28

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 131157, Temperature, water	Region 5
San Luis Drain

LOE ID:

230993

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2010-08-31 and 2011-06-28

Environmental Conditions:

QAPP Information:

SWAMP QAPrP 2008

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 131157, Temperature, water	Region 5
San Luis Drain

LOE ID:

230380

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2011-05-31 and 2013-09-25

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	119795	Region 5
San Luis Drain

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

Regional Board Conclusion:	Readily available data for this water body have not been used to determine standards attainment. No decision has been made regarding beneficial use support due to a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule. A decision regarding the beneficial use support of this water body will be made during a future Integrated Report cycle if it is determined that this water body is classified as a Water of the United States under the Navigable Waters Protection Rule.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because of a lack of clarity in the status of this water body under the Clean Water Act and the Navigable Waters Protection Rule.

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 119795, Tetrachlorvinphos	Region 5
San Luis Drain

LOE ID:

193991

Pollutant:

Tetrachlorvinphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Stirophos(Tetrachlorvinphos) is the USEPA Aquatic Life Benchmark of 0.125 ug/L for chronic toxicity in invertebrates (7 day average).

Guideline Reference:

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

Spatial Representation:

The samples were collected at 1 monitoring site (541MER535)

Temporal Representation:

The samples were collected between the dates of 2013-08-15 and 2013-08-15

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project


DECISION ID	159991	Region 5
San Luis Drain

Pollutant:	Total Dissolved Solids
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:	Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159991, Total Dissolved Solids	Region 5
San Luis Drain

LOE ID:

346122

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP BDAT data for San Luis Drain to determine beneficial use support and results are as follows: 6 of 6 samples exceeded the upper limit of the range for Total Dissolved Solids. Additionally, 0 of the 6 samples fall within the range, and 0 of 6 samples fall below the threshold.

Data 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)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary MCL that is incorporated by reference into the Water Quality Control Plan for the Sacramento and San Joaquin River Basins specifies a range for total dissolved solids of 500-1000 mg/L assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541MER535 (San Luis Drain @ Terminus).

Temporal Representation:

The samples were collected between the dates of 1997-06-26 and 2002-11-26

Environmental Conditions:

QAPP Information:

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)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159991, Total Dissolved Solids	Region 5
San Luis Drain

LOE ID:

333029

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Grasslands Bypass Project data for San Luis Drain to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the upper limit of the range for Total Dissolved Solids. Additionally, 0 of the 1 samples fall within the range, and 0 of 1 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, WQ from the Grasslands Bypass Project for the 2026 Integrated Report in Region 5

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541SLDGCR (San Luis Drain - Gun Club Road).

Temporal Representation:

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

Environmental Conditions:

QAPP Information:

GBP QAPP - Grasslands Bypass Project

QAPP Information Reference(s):

SWRCB - Region5 - GBP QAPP - Grasslands Bypass Project - 402652

Line of Evidence (LOE) for Decision ID 159991, Total Dissolved Solids	Region 5
San Luis Drain

LOE ID:

346104

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin River SWAMP Monitoring Data - Drainage Basin Inflows data for San Luis Drain to determine beneficial use support and results are as follows: 3 of 3 samples exceeded the upper limit of the range for Total Dissolved Solids. Additionally, 0 of the 3 samples fall within the range, and 0 of 3 samples fall below the threshold.

Data Reference:

Monitoring Data from the Surface Water Ambient Monitoring Program (SWAMP), San Joaquin River Basin - 2007 Data Review

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: MER535 (MER535).

Temporal Representation:

The samples were collected between the dates of 2000-12-28 and 2002-11-26

Environmental Conditions:

QAPP Information:

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)

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 159991, Total Dissolved Solids	Region 5
San Luis Drain

LOE ID:

346090

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP BDAT data for San Luis Drain to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the upper limit of the range for Total Dissolved Solids. Additionally, 0 of the 1 samples fall within the range, and 0 of 1 samples fall below the threshold.

Data 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)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541MER562 (Inflow to San Luis Drain).

Temporal Representation:

The samples were collected between the dates of 2000-04-26 and 2000-04-26

Environmental Conditions:

QAPP Information:

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)

QAPP Information Reference(s):


DECISION ID	159992	Region 5
San Luis Drain

Pollutant:	Zinc
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2020)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Readily available data for this waterbody were not used to determine standards attainment as the status of the waterbody as a water of the United States is uncertain. The 303(d) list is authorized under the Clean Water Act and is therefore limited to waters of the United States. Data will be used to determine standards attainment during a future Integrated Report cycle if it is determined that this water body is classified as a water of the United States.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the listing status for this water body-pollutant combination should not change this cycle because of a lack of clarity in the status of this water body under the Clean Water Act.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 159992, Zinc	Region 5
San Luis Drain

LOE ID:

194268

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, Water data for the 2020/2022 integrated report in Region 5.

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 (541MER535)

Temporal Representation:

The samples were collected between the dates of 2012-06-06 and 2012-06-06

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grasslands Bypass Project

QAPP Information Reference(s):

Quality Assurance Project Plan for the Compliance Monitoring Program for the Operation of the Grassland Bypass Project

Line of Evidence (LOE) for Decision ID 159992, Zinc	Region 5
San Luis Drain

LOE ID:

346139

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP BDAT data for San Luis Drain to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Zinc.

Data Reference: