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

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name:	Westley Wasteway (Stanislaus County)
Water Body ID:	CAR5411000020080808192151
Water Body Type:	River & Stream


DECISION ID	164235	Region 5
Westley Wasteway (Stanislaus County)

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

Regional Board Conclusion:	LOEs for this waterbody-pollutant combination from previous cycles were reviewed, found to be of insufficient quality to meet the requirements of Listing Policy section 6.1.4, and retired. This resulted in retirement of this decision.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 164235, Dimethoate	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

357463

Pollutant:

Dimethoate

LOE Subgroup:

Ancillary Line of Evidence

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data from previous cycles for this waterbody-pollutant combination were reviewed and found to be of insufficient quality to meet the requirements of section 6.1.4 of the Listing Policy. LOE 26127 was retired.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins; Fifth Edition. Revised May 2018 (with approved amendments)

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

Data from previous cycles for this waterbody-pollutant were not supported by an approved QAPP or did not meet the requirements of Section 6.1.4 of the Listing Policy. These data were deemed to be of insufficient quality to be included in this assessment.

QAPP Information Reference(s):

This is a placeholder for previously assessed data that does not have quality assurance information but would require it under newly developed policies. These LOEs were previously assessed and approved at the Regional, State and Federal level in past cycles. The LOEs needed to be moved and/or reassessed but required this reference code for movement within the decision making database.


DECISION ID	119147	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Aldicarb
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 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 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 119147, Aldicarb	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

185924

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 3 ug/L

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 119147, Aldicarb	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72177

Pollutant:

Aldicarb

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for Aldicarb.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

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. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The Department of Public Health archived advisory level for aldicarb is 7 ug/L.

Guideline Reference:

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

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/14/2007.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	119148	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Aldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 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 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 119148, Aldrin	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72199

Pollutant:

Aldrin

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Aldrin.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The CTR objective for aldrin to protect human health from the consumption of water and organisms is 0.00013 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 119148, Aldrin	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

185981

Pollutant:

Aldrin

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 43 samples were collected, 43 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Aldrin criteria for the protection of human health from the consumption of water and organisms is 0.00013 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Date for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	159722	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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 159722, Arsenic	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72202

Pollutant:

Arsenic

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 18 samples exceed the criterion for Arsenic.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for arsenic is 0.010 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159722, Arsenic	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

186237

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for arsenic incorporated by reference in the Basin Plan is 0.010 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 159722, Arsenic	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

330763

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for arsenic incorporated by reference in the Basin Plan is 0.010 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-05-08 and 2021-10-12

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program


DECISION ID	119124	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Atrazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 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 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 119124, Atrazine	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72204

Pollutant:

Atrazine

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Atrazine.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for atrazine is 1 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 119124, Atrazine	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

186440

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for atrazine incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.001 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	159723	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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 159723, Cadmium	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

186771

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for cadmium incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.005 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 159723, Cadmium	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

186746

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for cadmium incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.005 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 159723, Cadmium	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

330876

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for cadmium incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.005 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-05-08 and 2021-03-19

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 159723, Cadmium	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72227

Pollutant:

Cadmium

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 18 samples exceed the criterion for Cadmium.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for cadmium is 5 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	119126	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Carbofuran
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 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 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 119126, Carbofuran	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72244

Pollutant:

Carbofuran

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for Carbofuran.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for Carbofuran is 18 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/14/2007.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 119126, Carbofuran	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

187070

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.018 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	159724	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Chlordane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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 159724, Chlordane	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

333023

Pollutant:

Chlordane

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Total Chlordane. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The chlordane criterion for the protection of human health from the consumption of water and organisms is 0.00057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-05-08 and 2018-07-10

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 159724, Chlordane	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

187077

Pollutant:

Chlordane

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlordane. Although a total of 43 samples were collected, 43 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Chlordane criterion for the protection of human health from the consumption of water and organisms is 0.00057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Date for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	159725	Region 5
Westley Wasteway (Stanislaus County)

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:	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 159725, Copper	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

331053

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-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: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-10-09 and 2021-10-12

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 159725, Copper	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

346333

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2011-12-13 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	169920	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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 169920, DDD (Dichlorodiphenyldichloroethane)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

331219

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 27 samples were collected, 27 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDD criterion for the protection of human health from the consumption of water and organisms is 0.00083 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-05-08 and 2021-08-10

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 169920, DDD (Dichlorodiphenyldichloroethane)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

188190

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 44 samples were collected, 44 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDD(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Date for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	169925	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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 169925, DDE (Dichlorodiphenyldichloroethylene)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

188223

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 43 samples were collected, 43 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDE(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Date for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 169925, DDE (Dichlorodiphenyldichloroethylene)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

331267

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 27 samples were collected, 27 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDE [DDE(p,p')] criterion to protect human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-05-08 and 2021-08-10

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program


DECISION ID	169930	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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 169930, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

188522

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 44 samples were collected, 44 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDT(p,p) criteria for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Date for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 169930, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

331306

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 27 samples were collected, 27 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDT(4,4') criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-05-08 and 2021-08-10

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program


DECISION ID	119130	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Dieldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
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 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 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 119130, Dieldrin	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

188798

Pollutant:

Dieldrin

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dieldrin. Although a total of 44 samples were collected, 44 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Dieldrin criteria for the protection of human health from the consumption of water and organisms is 0.00014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Date for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 119130, Dieldrin	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72015

Pollutant:

Dieldrin

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Dieldrin.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The criterion for Dieldrin to protect human health from the consumption of water and organisms is 0.00014 ug/L (California Toxics Rule).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	119131	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Endosulfan sulfate
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 119131, Endosulfan sulfate	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

189322

Pollutant:

Endosulfan sulfate

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 43 samples exceeded the water quality threshold for Endosulfan Sulfate.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endosulfan sulfate criteria for the protection of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	119132	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Endrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 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 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 119132, Endrin	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

189351

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endrin criteria for the protection of human health from the consumption of water and organisms is 0.76 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 119132, Endrin	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72041

Pollutant:

Endrin

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Endrin.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endrin criterion for the protection of human health from the consumption of water and organisms is 0.76 ug/L. (California Toxics Rule, 2000)

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	119133	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Heptachlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 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 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 119133, Heptachlor	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72057

Pollutant:

Heptachlor

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The CTR objective for Heptachlor to protect human health from the consumption of water and organisms is 0.00021 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 119133, Heptachlor	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

190432

Pollutant:

Heptachlor

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor. Although a total of 43 samples were collected, 43 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor criteria for the protection of human health from the consumption of water and organisms is 0.00021 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Date for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	119134	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Heptachlor epoxide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 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 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 119134, Heptachlor epoxide	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

190624

Pollutant:

Heptachlor epoxide

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor Epoxide. Although a total of 42 samples were collected, 42 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor Epoxide criteria for the protection of human health from the consumption of water and organisms is 0.0001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Date for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 119134, Heptachlor epoxide	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72059

Pollutant:

Heptachlor epoxide

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor epoxide.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The CTR objective for Heptachlor epoxide to protect human health from the consumption of water and organisms is 0.0001 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	119150	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Hexachlorocyclohexane (HCH), alpha
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 119150, Hexachlorocyclohexane (HCH), alpha	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

189965

Pollutant:

Hexachlorocyclohexane (HCH), alpha

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for HCH, alpha-. Although a total of 44 samples were collected, 44 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The alpha-HCH (alpha-BHC) criteria for the protection of human health from consumption of water and organisms is 0.0039 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Date for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	119149	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Hexachlorocyclohexane (HCH), beta
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 119149, Hexachlorocyclohexane (HCH), beta	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

190113

Pollutant:

Hexachlorocyclohexane (HCH), beta

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support and the results are as follows: 0 of the 43 samples exceeded the water quality threshold for HCH, beta-. Although a total of 44 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The BHC, beta criteria for the protection of human health from the consumption of water and organisms is 0.014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Data for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	159726	Region 5
Westley Wasteway (Stanislaus County)

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 159726, Lead	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

190847

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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 (541XWWNCR)

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 159726, Lead	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

190915

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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 (541XWWNCR)

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 159726, Lead	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

331733

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-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: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-05-08 and 2021-10-12

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program


DECISION ID	119136	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 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 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 119136, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72719

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for HCH, gamma.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for HCH, gamma (Lindane) is 0.2 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 119136, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

190120

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support and the results are as follows: 0 of the 43 samples exceeded the water quality threshold for HCH, gamma-. Although a total of 44 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The BHC, gamma(Lindane) criteria for the protection of human health from the consumption of water and organisms is 0.019 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Data for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	119137	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Methoxychlor
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 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 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 119137, Methoxychlor	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72726

Pollutant:

Methoxychlor

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Methoxychlor.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for Methoxychlor, 30 ug/L, is incorporated by reference into the (Water Quality Control Plan, Central Valley Region, Sacramento and San Joaquin Basins).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 119137, Methoxychlor	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

191343

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Methoxychlor incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.03 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	159727	Region 5
Westley Wasteway (Stanislaus County)

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:	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 159727, Nickel	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72404

Pollutant:

Nickel

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 17 samples exceed the criterion for Nickel.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for nickel is 0.1 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159727, Nickel	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

191756

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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 (541XWWNCR)

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 159727, Nickel	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

191956

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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 (541XWWNCR)

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 159727, Nickel	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

331882

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 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: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-05-08 and 2021-03-19

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program


DECISION ID	159728	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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 159728, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72406

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Nitrate/Nitrite as N.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for nitrate + nitrite (as N) is 10.0 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 4/8/2008-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 159728, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

331917

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 1 of 31 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Primary California Maximum Contaminant Level for nitrate + nitrite (as N) incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L (California Code of Regulations, Title 22).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-05-08 and 2021-10-12

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 159728, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

192055

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 1 of 65 samples exceeded the water quality threshold for Nitrate + Nitrite as N.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for nitrate + nitrite (as N) incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 10 mg/L (California Code of Regulations, Title 22).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2010-09-16 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	119140	Region 5
Westley Wasteway (Stanislaus County)

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

Regional Board Conclusion:	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 119140, Oxamyl (Vydate)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

192735

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Oxamyl 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 (541XWWNCR)

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	159729	Region 5
Westley Wasteway (Stanislaus County)

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 159729, Selenium	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

193290

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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 (541XWWNCR)

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 159729, Selenium	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

332643

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 Irrigated Lands Regulatory Program for the 2026 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: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-05-08 and 2021-10-12

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 159729, Selenium	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72469

Pollutant:

Selenium

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 18 samples exceed the criterion for Selenium.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for selenium is 0.05 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	159730	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Simazine
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 159730, Simazine	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

193702

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Simazine incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.004 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 159730, Simazine	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

332652

Pollutant:

Simazine

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 Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Primary Maximum Contaminant Level for Simazine incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.004 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-08-14 and 2018-08-14

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 159730, Simazine	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72471

Pollutant:

Simazine

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Simazine.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for Simazine is 4 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	169905	Region 5
Westley Wasteway (Stanislaus County)

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 169905, Specific Conductivity	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

332696

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 5 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 1 of the 5 samples fall within the range, and 4 of 5 samples fall below the threshold.

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 Integrated Report in Region 5

SWAMP Data:

Non-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: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2017-10-10 and 2021-10-12

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program

Line of Evidence (LOE) for Decision ID 169905, Specific Conductivity	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

346637

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the upper limit of the range for SpecificConductivity. Additionally, 3 of the 8 samples fall within the range, and 5 of 8 samples fall below the threshold.

Data Reference:

Field, Habitat, Sediment, 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: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2010-10-12 and 2017-08-08

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	166513	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Total Dissolved Solids
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(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:	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 166513, Total Dissolved Solids	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

346734

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 9 samples exceeded the upper limit of the range for Total Dissolved Solids. Additionally, 6 of the 9 samples fall within the range, and 3 of 9 samples fall below the threshold.

Data Reference:

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

SWAMP Data:

Non-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: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2010-10-12 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	119145	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Toxaphene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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 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 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 119145, Toxaphene	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72502

Pollutant:

Toxaphene

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Toxaphene criterion for the protection of human health from the consumption of water and organisms is 0.00073 ug/L. (California Toxics Rule, 2000)

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 119145, Toxaphene	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

193905

Pollutant:

Toxaphene

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 Westside San Joaquin River Watershed Coalition data for Westley Wasteway (Stanislaus County) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Toxaphene. Although a total of 45 samples were collected, 45 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Toxaphene criteria for the protection of human health from the consumption of water and organisms is 0.00073 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

Date for this waterbody was collected over the date range 2011-03-08 to 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	159731	Region 5
Westley Wasteway (Stanislaus County)

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:	LOE 194405 has been replaced by LOE 346817 due to a reassessment of data. 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 159731, Zinc	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

346817

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Secondary Maximum Contaminant Level for zinc incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 5.0 mg/L assessed as an annual average.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2011-12-13 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition

Line of Evidence (LOE) for Decision ID 159731, Zinc	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

333068

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Irrigated Lands Regulatory Program for the 2026 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: 541XWWNCR (Westley Wasteway near Cox Road).

Temporal Representation:

The samples were collected between the dates of 2018-08-14 and 2021-03-19

Environmental Conditions:

QAPP Information:

QAPP Reference for Irrigated Lands Regulatory Program

QAPP Information Reference(s):

QAPP Reference for Irrigated Lands Regulatory Program


DECISION ID	119129	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	alpha-Endosulfan (Endosulfan 1)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	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 119129, alpha-Endosulfan (Endosulfan 1)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

189414

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The alpha-endosulfan criteria for the protection of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	119141	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	beta-Endosulfan (Endosulfan 2)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	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 119141, beta-Endosulfan (Endosulfan 2)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

189595

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The beta-endosulfan criteria for the protection of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

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

Temporal Representation:

The samples were collected between the dates of 2011-03-08 and 2018-02-13

Environmental Conditions:

QAPP Information:

Pacific EcoRisk. 2013. QAPP for Westside San Joaquin River Watershed Coalition.

QAPP Information Reference(s):

QAPP for Westside San Joaquin River Watershed Coalition


DECISION ID	72785	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.2 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Eighteen of the 42 samples exceed the evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eighteen of 42 samples exceeded the evaluation guideline and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 72785, Indicator Bacteria	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72043

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 5 of 20 samples exceed the criterion for Escherichia coli.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The USEPA recommended objective for single sample maximum allowable density of E. coli in freshwater designated beach areas is 235 MPN/100mL.

Guideline Reference:

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 72785, Indicator Bacteria	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

23243

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The Westside San Joaquin River Water Quality Coalition collected 22 samples from July 2004 to October 2006. Thirteen out of 22 samples exceeded the evaluation objective.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. The objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Evaluation Guideline:

The USEPA E. Coli objective of 235/100 mL in any single sample (USEPA 1986).

Guideline Reference:

Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002

Spatial Representation:

Samples were collected at two locations: Westley Wasteway at Refuge Ponds and Westley Wasteway near Cox Road.

Temporal Representation:

Sampling occurred from July 2004 to October 2006.

Environmental Conditions:

QAPP Information:

Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):


DECISION ID	92289	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with action other than TMDL)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with action other than TMDL)(2016)
Revision Status	Original
Sources:	Agriculture
Expected Attainment Date:	2026
Implementation Action Other than TMDL:	This water body segment-pollutant combination is being addressed through Basin Plan requirements established under CRWQCB-CVR resolution R5-20140041, and implemented through Board established Waste Discharge Requirements for agricultural discharges. The sources of chlorpyrifos to this segment have been identified as offsite movement of chlorpyrifos from chlorpyrifos applications by the agricultural dischargers regulated by the CRWQCB-CVR WDRs. The Basin Plan identifies numeric water quality objectives for diazinon and chlorpyrifos. The Basin Plan and WDRs require growers to implement management practices through the development and implementation of water quality management plans to meet water quality objectives for chlorpyrifos as soon as possible but no longer than ten years from the date of approval of the Basin Plan Amendment. These management plans are required to be developed and implemented within one year of the Basin Plan Amendment approval. Agricultural management practices to be implemented may include pest management practices, pesticide application practices, vegetation management practices and water management practices, all of which are effective in reducing offsite movement of chlorpyrifos into surface water. The Basin Plan and the Monitoring and Reporting programs in the WDRs require monitoring to determine if adequate reductions are being attained. The Basin Plan and WDRs require management practices to be iteratively improved through updates of the management plans until the water quality objectives are achieved.
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This water body - pollutant combination is being considered for removal from the 303(d) list under sections 2.2 and 4.11 of the Listing Policy. Under section 4.11, a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The evidence indicates that chlorpyrifos concentrations are not attaining the applicable water quality standards, but existing pollution control requirements, under State authority, are stringent enough to implement applicable water quality standards because the impairment is being addressed by an enforceable regulatory program, other than a TMDL, that is reasonably expected to result in attainment of the water quality standards within a reasonable, specified time frame. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Three of 20 available calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion. These exceedances occurred more than once every three years. 4. Three of 20 available 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion. These exceedances occurred more than once every three years. 5. The sources of chlorpyrifos to this water body segment have been identified as offsite movement of chlorpyrifos from chlorpyrifos applications by the agricultural dischargers, who are regulated under enforceable Waste Discharge Requirements (WDRs). 6. In 2016, the Board adopted Resolution R5-2014-0041 establishing Basin Plan amendments that primarily address the regulation of agricultural pesticide runoff and discharges of diazinon and chlorpyrifos in the Central Valley which are implemented through Board established Waste Discharge Requirements for agricultural dischargers. The amendments established numeric water quality objectives for chlorpyrifos and a control program to ensure that the objectives will be attained within a reasonable, specified time frame. The Basin Plan and WDRs require growers to implement management practices through the development and implementation of water quality management plans to meet water quality objectives for chlorpyrifos as soon as possible but no longer than ten years from the date of approval of the Basin Plan Amendment. These management plans are required to be developed and implemented within one year of the Basin Plan Amendment approval. 7. Agricultural management practices to be implemented may include pest management practices, pesticide application practices, vegetation management practices and water management practices, all of which are effective in reducing offsite movement of chlorpyrifos into surface water. 8. The Basin Plan and the Monitoring and Reporting programs in the Boards WDRs require monitoring to determine if adequate reductions are being attained. The Basin Plan and WDRs require management practices to be iteratively improved through updates of the management plans until the water quality objectives are attained. 9. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are being met.

Regional Board Decision Recommendation:	After review of the available data and information described in the lines of evidence associated with this decision, the Regional Water Board determined that this water body and pollutant combination is still impaired and that it should be listed as being addressed by another regulatory program that is reasonably expected to result in attainment of the water quality standard within a reasonable, specified time frame because an alternative State regulatory program is in place which can be reasonably expected to result in attainment of the water quality standard within a reasonable, specified time frame.

State Board Review of Regional Board Conclusion and Recommendation:	The Basin Plan and WDRs require growers to implement management practices through the development and implementation of water quality management plans to meet water quality objectives for chlorpyrifos as soon as possible but no longer than ten years from the date of approval of the Basin Plan Amendment. These management plans are required to be developed and implemented within one year of the Basin Plan Amendment approval. 7. Agricultural management practices to be implemented may include pest management practices, pesticide application practices, vegetation management practices and water management practices, all of which are effective in reducing offsite movement of chlorpyrifos into surface water. 8. The Basin Plan and the Monitoring and Reporting programs in the Boards WDRs require monitoring to determine if adequate reductions are being attained. The Basin Plan and WDRs require management practices to be iteratively improved through updates of the management plans until the water quality objectives are attained. 9. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are being met.

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 92289, Chlorpyrifos	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

23241

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Eleven water samples were collected from Westley Wasteway from July 2004 through August 2006, representing four calculated 4-day average chlorpyrifos concentrations and four 1-hour average chlorpyrifos concentrations. Two of four calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion of 0.015 ug/L. Two of four 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion of 0.025 ug/L. Seven water samples had method detection limits (0.02, 0.05, 0.032 ug/L) higher than the CDFG Hazard Assessment Chlorpyrifos 1-hour Criterion (0.015 ug/L) and, in accordance with Section 6.1.5.5 of the Listing Policy, these samples were not included in this analysis.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

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. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Objective/Criterion Reference:

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

Evaluation Guideline:

California Department of Fish and Game (CDFG) Hazard Assessment Chlorpyrifos Criteria: 0.015 ug/L as a 4-day average concentration, and 0.025 ug/L as a 1-hour average concentration, not to be exceeded more than once every three years.

Guideline Reference:

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

Spatial Representation:

Samples were collected from Westley Wasteway near Cox Road.

Temporal Representation:

Samples were collected biweekly from June 2004 through August 2006.

Environmental Conditions:

QAPP Information:

Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 92289, Chlorpyrifos	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72245

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 1 of 16 samples exceed the criterion for Chlorpyrifos.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	80303	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Diazinon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1, a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of sixteen available water sample results exceed the evaluation guidelines. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 16 available water sample results exceed the evaluation guideline, and this sample size is sufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 80303, Diazinon	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

71999

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for Diazinon.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	88753	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Glyphosate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data for this water segment-pollutant combination were received by the State Water Resources Control Board as part of the data solicitation for the 2014 Integrated Report Cycle. These data were not assessed as part of the 2014 Integrated Report.

Regional Board Decision Recommendation:	Data for this water segment - pollutant combination were not assessed by RWQCB staff during the 2014 Integrated Report cycle. RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list at this time. These data will be assessed by RWQCB staff during a future Integrated Report cycle to determine the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 88753, Glyphosate	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72055

Pollutant:

Glyphosate

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 5 samples exceed the criterion for Glyphosate.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for Glyphosate is 700 ug/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-7/10/2007.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	88830	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Methyl Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data for this water segment-pollutant combination were received by the State Water Resources Control Board as part of the data solicitation for the 2014 Integrated Report Cycle. These data were not assessed as part of the 2014 Integrated Report.

Regional Board Decision Recommendation:	Data for this water segment - pollutant combination were not assessed by RWQCB staff during the 2014 Integrated Report cycle. RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list at this time. These data will be assessed by RWQCB staff during a future Integrated Report cycle to determine the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 88830, Methyl Parathion	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72728

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The NAS health advisory level for methyl parathion is 30 µg/L.

Guideline Reference:

National Academy of Sciences - Volume I Drinking Water and Health

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	88904	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Molinate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data for this water segment-pollutant combination were received by the State Water Resources Control Board as part of the data solicitation for the 2014 Integrated Report Cycle. These data were not assessed as part of the 2014 Integrated Report.

Regional Board Decision Recommendation:	Data for this water segment - pollutant combination were not assessed by RWQCB staff during the 2014 Integrated Report cycle. RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list at this time. These data will be assessed by RWQCB staff during a future Integrated Report cycle to determine the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 88904, Molinate	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72730

Pollutant:

Molinate

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 6 samples exceed the criterion for Molinate.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for Molinate is 20 ug/L .

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/14/2007.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	88908	Region 5
Westley Wasteway (Stanislaus County)

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)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data for this water segment-pollutant combination were received by the State Water Resources Control Board as part of the data solicitation for the 2014 Integrated Report Cycle. These data were not assessed as part of the 2014 Integrated Report.

Regional Board Decision Recommendation:	Data for this water segment - pollutant combination were not assessed by RWQCB staff during the 2014 Integrated Report cycle. RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list at this time. These data will be assessed by RWQCB staff during a future Integrated Report cycle to determine the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 88908, Nitrogen, Nitrate	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72407

Pollutant:

Nitrogen, Nitrate

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 8 samples exceed the criterion for Nitrate as N.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for nitrate (NO3 as N) is 10.0 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-10/9/2007.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	88909	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Nitrogen, Nitrite
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data for this water segment-pollutant combination were received by the State Water Resources Control Board as part of the data solicitation for the 2014 Integrated Report Cycle. These data were not assessed as part of the 2014 Integrated Report.

Regional Board Decision Recommendation:	Data for this water segment - pollutant combination were not assessed by RWQCB staff during the 2014 Integrated Report cycle. RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list at this time. These data will be assessed by RWQCB staff during a future Integrated Report cycle to determine the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 88909, Nitrogen, Nitrite	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72408

Pollutant:

Nitrogen, Nitrite

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California primary maximum contaminant level for nitrite (as N) is 1 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-10/9/2007.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	88910	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Parathion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data for this water segment-pollutant combination were received by the State Water Resources Control Board as part of the data solicitation for the 2014 Integrated Report Cycle. These data were not assessed as part of the 2014 Integrated Report.

Regional Board Decision Recommendation:	Data for this water segment - pollutant combination were not assessed by RWQCB staff during the 2014 Integrated Report cycle. RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list at this time. These data will be assessed by RWQCB staff during a future Integrated Report cycle to determine the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 88910, Parathion	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72437

Pollutant:

Parathion

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 10 samples exceed the criterion for Parathion, Ethyl.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

The NAS health advisory level for parathion or ethyl parathion is 30 µg/L.

Guideline Reference:

National Academy of Sciences - Volume I Drinking Water and Health

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 4/8/2008-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	73089	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	Toxicity
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data for this water segment-pollutant combination were received by the State Water Resources Control Board as part of the data solicitation for the 2014 Integrated Report Cycle. These data were not assessed as part of the 2014 Integrated Report.

Regional Board Decision Recommendation:	Data for this water segment - pollutant combination were not assessed by RWQCB staff during the 2014 Integrated Report cycle. RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list at this time. These data will be assessed by RWQCB staff during a future Integrated Report cycle to determine the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 73089, Toxicity	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

23248

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Zero of 12 samples tested with Selenastrum capricornutum were toxic and violated the narrative toxicity objective.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CVRWQCB, 2007)

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control using a t-test with 4-day chronic-style toxicity tests.

Guideline Reference:

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

Spatial Representation:

Samples were collected from two locations: Westley Wasteway at Refuge Ponds and Westley Wasteway near Cox Road.

Temporal Representation:

Samples were collected from July 2004 to August 2006.

Environmental Conditions:

QAPP Information:

Data quality: Excellent. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 73089, Toxicity	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

23246

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Zero of the 12 samples tested with Pimephales promelas were toxic and violated the narrative toxicity objective.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control using a t-test with 4-day acute-style toxicity tests.

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-012

Spatial Representation:

Samples were collected from two locations: Westley Wasteway at Refuge Ponds and Westley Wasteway near Cox Road.

Temporal Representation:

Samples were collected from July 2004 to August 2006.

Environmental Conditions:

QAPP Information:

Data quality: Excellent. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 73089, Toxicity	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

23245

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

The one sample tested with Hyalella azteca was toxic and violated the narrative toxicity objective. One sample collected at WWNCR exhibited a statistically significant decrease in survival compared to the control. The sample date and percent of control (in parentheses) are as follows:10 October 2005 (0)

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:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control using a t-test with 10-day Hyalella azteca sediment toxicity tests.

Guideline Reference:

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

Spatial Representation:

Samples were collected from Westley Wasteway near Cox Road.

Temporal Representation:

The sample was collected October 10, 2005.

Environmental Conditions:

QAPP Information:

Data quality: Excellent. Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.

QAPP Information Reference(s):

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

Line of Evidence (LOE) for Decision ID 73089, Toxicity	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

23244

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One of the 2 samples tested with Hyalella azteca was toxic and violated the narrative toxicity objective. One sample collected at Westley Wasteway near Cox Road exhibited a statistically significant decrease in survival compared to the control. The sample date and percent of control (in parentheses) are as follows:11 September 2006 (1)

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control using a t-test with 10-day Hyalella azteca sediment toxicity tests.

Guideline Reference:

Spatial Representation:

Samples were collected from Westley Wasteway near Cox Road.

Temporal Representation:

Samples were collected in September 2004 and September 2006

Environmental Conditions:

QAPP Information:

Data quality: Excellent. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 73089, Toxicity	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

23240

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Zero of the 12 samples tested with Ceriodaphnia dubia were toxic and violated the narrative toxicity objective.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Statistically significant difference from control using a t-test with 4-day acute-style toxicity tests.

Guideline Reference:

Spatial Representation:

Samples were collected from two locations: Westley Wasteway at Refuge Ponds and Westley Wasteway near Cox Road.

Temporal Representation:

Samples were collected from July 2004 to August 2006.

Environmental Conditions:

QAPP Information:

Data quality: Excellent. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):


DECISION ID	88989	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	alpha.-BHC (Benzenehexachloride or alpha-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data for this water segment-pollutant combination were received by the State Water Resources Control Board as part of the data solicitation for the 2014 Integrated Report Cycle. These data were not assessed as part of the 2014 Integrated Report.

Regional Board Decision Recommendation:	Data for this water segment - pollutant combination were not assessed by RWQCB staff during the 2014 Integrated Report cycle. RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list at this time. These data will be assessed by RWQCB staff during a future Integrated Report cycle to determine the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 88989, alpha.-BHC (Benzenehexachloride or alpha-HCH)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72200

Pollutant:

alpha.-BHC (Benzenehexachloride or alpha-HCH)

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for HCH, alpha.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The HCH, alpha criterion, 0.0039 ug/L, is for the protection of human health from the consumption of water and organisms. (California Toxics Rule, 2002)

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	89068	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	beta-BHC (Benzenehexachloride or beta-HCH)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Data for this water segment-pollutant combination were received by the State Water Resources Control Board as part of the data solicitation for the 2014 Integrated Report Cycle. These data were not assessed as part of the 2014 Integrated Report.

Regional Board Decision Recommendation:	Data for this water segment - pollutant combination were not assessed by RWQCB staff during the 2014 Integrated Report cycle. RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list at this time. These data will be assessed by RWQCB staff during a future Integrated Report cycle to determine the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 89068, beta-BHC (Benzenehexachloride or beta-HCH)	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

72225

Pollutant:

beta-BHC (Benzenehexachloride or beta-HCH)

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 Ag Waiver data for Westley Wasteway (Stanislaus County) to determine beneficial use support and results are as follows: 0 of 16 samples exceed the criterion for HCH, beta.

Data Reference:

Data for Various Pollutants in Westside San Joaquin Water Quality Coalition, 2004-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The HCH, beta criterion for the protection of human health from the consumption of water and organisms is 0.014 ug/L (California Toxics Rule, 2002).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Westley Wasteway (Stanislaus County) was collected at 1 monitoring site [Westley Wasteway near Cox Road - 541XWWNCR]

Temporal Representation:

Data was collected over the time period 3/13/2007-8/11/2009.

Environmental Conditions:

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

QAPP Information:

Data for this line of evidence was collected as part of the Irrigated Lands Regulatory Program.

QAPP Information Reference(s):


DECISION ID	71864	Region 5
Westley Wasteway (Stanislaus County)

Pollutant:	pH
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The decision has not changed. Region 5 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle. This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Four of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Four of 34 samples exceeded the pH objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 71864, pH	Region 5
Westley Wasteway (Stanislaus County)

LOE ID:

23247

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The Westside San Joaquin Water Quality Coalition collected 34 samples from July 2004 to October 2006. Four out of 34 samples were outside the acceptable range; two samples were higher than the acceptable range and two samples were lower than the acceptable range.

Data Reference:

Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH of water shall not be depressed below 6.5,raised above 8.5, or changed at any time more than 0.5 units from normal ambient pH.

Objective/Criterion Reference:

Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from two locations: Westley Wasteway at Refuge Ponds and Westley Wasteway near Cox Road.

Temporal Representation:

Sampling occurred from July 2004 to October 2006.

Environmental Conditions:

QAPP Information:

Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)

QAPP Information Reference(s):