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

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118945, Aldicarb	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72074

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 Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Aldicarb.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthall Slough @ Woodward Ave - 535WSAWAV]. Some data collected from Walthall Slough @ Woodward Ave used an alternate site code - 544WSAWAV

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118945, Aldicarb	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

221469

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_SJCDWQC data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 12 samples exceeded the water quality threshold for Aldicarb.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	118946	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. Zero of the zero and zero of zero samples exceed for each of the COM and MUN, zero of the 12 samples exceed the WARM, and zero of six samples for COLD water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the zero and zero of zero samples exceed for each of the COM and MUN, zero of the 12 samples exceed the WARM, and zero of six samples for COLD water quality objective, and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118946, Aldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72089

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The criterion maximum concentration to protect aquatic life in freshwater for aldrin is 1.5 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118946, Aldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186082

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The established numeric criteria for aldrin to protect aquatic life in freshwater as an instantaneous maximum concentration is 3 ug/L . This established criteria was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000.

Objective/Criterion Reference:

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118946, Aldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

185973

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 consumption of organisms only 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118946, Aldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

185980

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:

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:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118946, Aldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72075

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118946, Aldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72076

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Aldrin. Twelve samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The criterion to protect human health from consumption of organisms only for aldrin is 0.00014 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118898	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). LOE 72107 has been replaced by LOE 221726 due to a reassessment of data using a U.S. EPA aquatic life benchmark. The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118898, Atrazine	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186249

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118898, Atrazine	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186506

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118898, Atrazine	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72108

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118898, Atrazine	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

221726

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	118914	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	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 one line(s) of evidence are necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of the zero samples exceed the Evaluation Guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of zero samples exceeded Evaluation Guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118914, Azinphos-methyl (Guthion)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186293

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 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:

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

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria for azinphos methyl for freshwater aquatic life protection is 0.01 ug/l (instantaneous maximum)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118914, Azinphos-methyl (Guthion)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72109

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 National Recommended Water Quality criterion for Azinphos Methyl (Guthion) for the protection of freshwater aquatic life is a maximum of 0.01 ug/l.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118937	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118937, Bifenthrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186645

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 5 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Bifenthrin is 0.1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Bifenthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Bifenthrin

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-05-15 to 2018-09-18

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118899	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118899, Boron	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186546

Pollutant:

Boron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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:

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

Objective/Criterion Reference:

Evaluation Guideline:

Water Quality for Agriculture, published by the Food and Agriculture Organization of the United Nations in 1985, contains criteria protective of various agricultural uses of water, including irrigation of various types of crops and stock watering. At or below the limits presented in the Water Quality Goals tables, agricultural uses of water should not be limited. These criteria were used to translate narrative water quality objectives for chemical constituents that prohibit chemicals in concentrations that would impair agricultural uses of water. The criteria for boron is 700 ug/L (0.7 mg/L).

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118900	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. Zero of the six water samples reported as a dissolved fraction exceed the criterion for COLD; zero of the sixteen water samples reported as a dissolved fraction exceed the objective for MUN; zero of the twenty-eight water samples reported as a total fraction exceed the objective for MUN; and zero of the twelve water samples reported as a total fraction exceed the criterion for WARM. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the six water samples reported as a dissolved fraction exceed the criterion for COLD; zero of the sixteen water samples reported as a dissolved fraction exceed the objective for MUN; zero of the twenty-eight water samples reported as a total fraction exceed the objective for MUN; and zero of the twelve water samples reported as a total fraction exceed the criterion for WARM and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118900, Cadmium	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186857

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118900, Cadmium	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186539

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118900, Cadmium	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186657

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118900, Cadmium	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72135

Pollutant:

Cadmium

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 AgWaiver data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Cadmium.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The cadmium criterion in freshwater is hardness-dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [ Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118900, Cadmium	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72124

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118901	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 57 samples exceed the evaluation guideline for aquatic life. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 57 samples exceed the evaluation guideline for aquatic life and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118901, Carbaryl	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72136

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 USEPA recommended water quality criterion for freshwater aquatic life for carbaryl is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118901, Carbaryl	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

187152

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA recommended water quality criteria for freshwater aquatic life for carbaryl is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118902	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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:	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. Four lines of evidence are available in the administrative record to assess this pollutant. Zero of 57 samples exceed the objective for MUN. Zero of 57 samples exceed the evaluation guideline for aquatic life. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of 57 samples exceed the objective for MUN. Zero of 57 samples exceed the evaluation guideline for aquatic life. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118902, Carbofuran	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72137

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 maximum concentration for carbofuran is 0.5 µg/L (DFG 92-3, 1992).

Guideline Reference:

Hazard Assessment of the Insecticide Carbofuran to Aquatic Organisms in the Sacramento River System

Spatial Representation:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118902, Carbofuran	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186957

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118902, Carbofuran	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

187026

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The interim water quality criterion for the protection of sensitive aquatic organisms from Carbofuran is 0.5 ug/l (DFG 92-3, 1992).

Guideline Reference:

Hazard Assessment of the Insecticide Carbofuran to Aquatic Organisms in the Sacramento River System

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118902, Carbofuran	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72138

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118903	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118903, Chlordane	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

187104

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 consumption of organisms only 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118903, Chlordane	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

187058

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 San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118903, Chlordane	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

186984

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The Chlordane criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0043 ug/L (California Toxics Rule, 2000).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118958	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118958, Chloropicrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

187344

Pollutant:

Chloropicrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chloropicrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Chloropicrin is the USEPA Aquatic Life Benchmark of 5.5 ug/L for a fish (acute).

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-03-14 to 2018-04-10

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118904	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

Pollutant:	Chlorpyrifos
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:	Data for this waterbody has been considered; however, there is insufficient information to determine beneficial use support for the large and complex Delta subarea. Decisions regarding the Delta subareas will be phased out of the Integrated Report during future cycles and data will be reevaluated as part of localized assessments where data is more representative of water quality in the described segment. Due to this change, new decisions for the Delta subareas will not be assessed for the 2020/2022 cycle. Decisions regarding the beneficial use support of individual waterbodies within the Delta will be made during a future Integrated Report cycle.

Regional Board Decision Recommendation:	After review, RWQCB staff concludes that the listing decision will not change during the current cycle and the specific waterbody will be reassessed in future cycles. Assessments for Delta Subareas will be phased out of the Integrated Report during future cycles and these data will be reevaluated as part of localized assessments where data is more representative of water quality.

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 118904, Chlorpyrifos	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

187347

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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:

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

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-08-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118904, Chlorpyrifos	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

195967

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin 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 evaluation guideline for chlorpyrifos, 0.177 ug/g, is one-tenth of the median lethal concentration (LC50; 1.77 ug/g) and is normalized by the percentage of organic carbon in the sediment sample (Amweg and Weston, 2007).

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 544WSAWAV.

Temporal Representation:

Date for this waterbody were collected over the date range 2010-09-07 to 2010-09-07

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118904, Chlorpyrifos	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72139

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Spatial Representation:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118942	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant for aquatic life. Zero of the 55 samples exceed the guideline for the aquatic life use. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 55 samples exceed the guideline for the aquatic life use and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118942, Cyanazine	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

187703

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118942, Cyanazine	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72155

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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	118950	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118950, Cyfluthrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

196297

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin, total. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

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 evaluation guideline for cyfluthrin, 0.11 ug/g, is one-tenth of the median lethal concentration (LC50; 1.1 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin from Amweg et al. (2005).

Guideline Reference:

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

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 544WSAWAV.

Temporal Representation:

Date for this waterbody were collected over the date range 2010-09-07 to 2010-09-07

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118950, Cyfluthrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

187729

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Cyfluthrin is 0.2 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Cyfluthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Bifenthrin

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-07-17 to 2018-09-18

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118952	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118952, Cyhalothrin, Lambda	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190818

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 2 samples were collected, 2 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Lambda-cyhalothrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Lambda-cyhalothrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-02-20 to 2018-03-14

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118952, Cyhalothrin, Lambda	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

196088

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

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 evaluation guideline for lambda-cyhalothrin, 0.044 ug/g, is one-tenth of the median lethal concentration (LC50; 0.44 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin from Amweg et al. (2005).

Guideline Reference:

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

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 544WSAWAV.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-07 to 2010-09-07

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118938	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118938, Cypermethrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

196254

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

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 evaluation guideline for cypermethrin, 0.03 ug/g, is one-tenth of the median lethal concentration (LC50; 0.3 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al. (2002).

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 544WSAWAV.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-07 to 2010-09-07

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118938, Cypermethrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188113

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 4 samples were collected, 4 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Cypermethrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Cypermethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Cypermethrin

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-02-20 to 2018-08-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	127554	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 127554, DDD (Dichlorodiphenyldichloroethane)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188124

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 16 samples were collected, 16 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 criteria for the protection of human health from consumption of organisms only is 0.00084 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 127554, DDD (Dichlorodiphenyldichloroethane)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188157

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 San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 16 samples were collected, 16 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	127556	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 127556, DDE (Dichlorodiphenyldichloroethylene)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

187996

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 16 samples were collected, 16 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 consumption of organisms only is 0.00084 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 127556, DDE (Dichlorodiphenyldichloroethylene)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188019

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 San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 16 samples were collected, 16 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	127557	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 127557, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188540

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 16 samples were collected, 16 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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-4,4' criteria for the protection of human health from consumption of organisms only 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 127557, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188375

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 16 samples were collected, 16 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.005 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 127557, DDT (Dichlorodiphenyltrichloroethane)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188435

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 San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 16 samples were collected, 16 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118951	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118951, Deltamethrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

196592

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

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 evaluation guideline for deltamethrin, 0.079 ug/g, is one-tenth of the median lethal concentration (LC50; 0.79 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin from Amweg et al. (2005).

Guideline Reference:

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

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 544WSAWAV.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-07 to 2010-09-07

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118954	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118954, Demeton	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188506

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118906	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118906, Diazinon	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188410

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-08-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118906, Diazinon	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72156

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118907	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118907, Dichlorvos	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188631

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 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:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118908	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the twenty-eight samples exceed the evaluation guideline for COLD. LOE 72157 has been replaced by LOE 221502 due to a reassessment of data using a U.S. EPA aquatic life benchmark. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the twenty-eight samples exceed the evaluation guideline for COLD and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118908, Dicofol	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188677

Pollutant:

Dicofol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dicofol is the USEPA Aquatic Life Benchmark of 4.4 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118908, Dicofol	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

221502

Pollutant:

Dicofol

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Dicofol is the USEPA Aquatic Life Benchmark of 4.4 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	118909	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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:	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. Six lines of evidence are available in the administrative record to assess this pollutant. Zero of the twenty-eight samples exceed the criterion for COLD/WARM; zero of the zero samples exceed the criterion for COMM; and zero of the zero samples exceed the criterion for MUN. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the twenty-eight samples exceed the criterion for COLD/WARM; zero of the zero samples exceed the criterion for COMM; and zero of the zero samples exceed the criterion for MUN and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118909, Dieldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188816

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 San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 16 samples were collected, 16 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118909, Dieldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72170

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118909, Dieldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72168

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118909, Dieldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72169

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Dieldrin. Twelve samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Dieldrin criterion for the protection of human health from consumption of organisms only, is 0.00014 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118909, Dieldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188601

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118909, Dieldrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

188718

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 16 samples were collected, 16 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 consumption of organisms only 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118940	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Previously considered water quality data was reevaluated according to new guidelines as part of this assessment. Line of evidence #72171 was replaced by #221690. Two lines of evidence are available in the administrative record to assess this pollutant. One of the 55 samples exceed the evaluation guideline for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. One of 55 samples exceeded the evaluation guideline and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 118940, Dimethoate	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

221690

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

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 118940, Dimethoate	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189146

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118910	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status. Two lines of evidence is available in the administrative record to assess this pollutant. Zero of the 12 samples exceed the Evaluation Guideline for WARM. Zero of zero samples exceed the Evaluation Guideline for COLD. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 12 samples exceed the Evaluation Guideline for WARM. Zero of zero samples exceed the Evaluation Guideline for COLD. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of 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 118910, Disulfoton	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189170

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Disulfoton. Although a total of 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:

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

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118910, Disulfoton	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72172

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 USEPA National Recommended Water Quality criterion for disulfoton in freshwater (0.05 ug/L) is an aquatic life maximum (instantaneous) level.

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118911	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118911, Diuron	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189094

Pollutant:

Diuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of diuron does not exceed 1.3 ug/L (UC Davis Aquatic Life Criteria).

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118912	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. Two lines of evidence are available to assess for Municipal and Domestic Supply. Two lines of evidence are available to assess for aquatic life. Two lines of evidence are available to assess for Commercial or recreational collection of fish, shellfish, or organisms. Zero of the 28 samples, reported as a total concentration or with the fraction not reported, exceed the criterion for Municipal and Domestic Supply. Zero of the 28 samples, reported as a total concentration or with the fraction not reported, exceed the criterion for aquatic life. Zero of the 28 samples, reported as a total concentration or with the fraction not reported, exceed the criterion for Commercial or recreational collection of fish, shellfish, or organisms. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 28 samples, reported as a total concentration or with the fraction not reported, exceed the criterion for Municipal and Domestic Supply. Zero of the 28 samples, reported as a total concentration or with the fraction not reported, exceed the criterion for aquatic life. Zero of the 28 samples, reported as a total concentration or with the fraction not reported, exceed the criterion for Commercial or recreational collection of fish, shellfish, or organisms. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118912, Endrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72190

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L. (California Toxics Rule, 2000)

Objective/Criterion Reference:

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118912, Endrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189404

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118912, Endrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72189

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endrin criterion for the protection of human health from consumption of organisms only is 0.81 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118912, Endrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189589

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118912, Endrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189609

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endrin criteria for the protection of human health from consumption of organisms only is 0.81ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118912, Endrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72188

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118955	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118955, Esfenvalerate/Fenvalerate	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

196585

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate/Fenvalerate, Total. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

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 evaluation guideline for esfenvalerate/fenvalerate, 0.15 ug/g, is one-tenth of the median lethal concentration (LC50; 1.5 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate from Amweg et al. (2005).

Guideline Reference:

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

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 544WSAWAV.

Temporal Representation:

Date for this waterbody were collected over the date range 2010-09-07 to 2010-09-07

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118955, Esfenvalerate/Fenvalerate	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189936

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Esfenvalerate. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Esfenvalerate is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Esfenvalerate were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Esfenvalerate

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-02-20 to 2018-06-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118953	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118953, Fenpropathrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

196344

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Fenpropathrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

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 evaluation guideline for fenpropathrin, 0.1 ug/g, is one-tenth of the median lethal concentration (LC50; 1 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1 ug/g is the geometric mean of LC50 values for fenpropathrin from Ding et al. ( 2011).

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 544WSAWAV.

Temporal Representation:

Date for this waterbody were collected over the date range 2010-09-07 to 2010-09-07

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118953, Fenpropathrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189926

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Fenpropathrin is the USEPA Aquatic Life Benchmark of 0.06 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2018-05-15 and 2018-09-18

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118913	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. LOE 72213 has been replaced by LOE 221959 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118913, Glyphosate	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72214

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118913, Glyphosate	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

221959

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

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 118913, Glyphosate	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190286

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-07-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118913, Glyphosate	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189964

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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 Glyphosate incorporated by reference in the Water Quality Control Plan for the Sacramento and San Joaquin River Basins is 0.7 mg/L.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-07-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118915	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118915, Heptachlor	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72216

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor. Twelve samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor criterion for the protection of human health from consumption of organisms only is 0.00021 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118915, Heptachlor	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72215

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118915, Heptachlor	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72236

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118915, Heptachlor	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190443

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 San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118915, Heptachlor	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190571

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 consumption of organisms only 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118915, Heptachlor	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190404

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118916	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118916, Heptachlor epoxide	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190456

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118916, Heptachlor epoxide	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190619

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 San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118916, Heptachlor epoxide	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190519

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 consumption of organisms only is 0.00011 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118916, Heptachlor epoxide	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72239

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor Epoxide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118916, Heptachlor epoxide	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72238

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Heptachlor epoxide. Twelve samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Heptachlor Epoxide criterion for the protection of human health from consumption of organisms only is 0.00011 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118916, Heptachlor epoxide	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72237

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118949	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118949, Hexachlorocyclohexane (HCH), alpha	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189968

Pollutant:

Hexachlorocyclohexane (HCH), alpha

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The alpha-HCH (alpha-BHC) criteria for the protection of human health from consumption of organisms only is 0.013 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118949, Hexachlorocyclohexane (HCH), alpha	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190179

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 San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) 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 13 samples were collected, 13 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118948	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118948, Hexachlorocyclohexane (HCH), beta	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190110

Pollutant:

Hexachlorocyclohexane (HCH), beta

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The BHC, beta criteria for the protection of human health from consumption of organisms only is 0.046 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118948, Hexachlorocyclohexane (HCH), beta	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190207

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:

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118934	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118934, Imidacloprid	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190792

Pollutant:

Imidacloprid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Imidacloprid. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-04-10 to 2018-07-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	127020	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence are available in the administrative record to assess this pollutant for Water Contact Recreation (REC-1). Six of the 88 samples, expressed as a Statistical Threshold Value, exceed the objective for REC-1. 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. Six of the 88 samples, expressed as a Statistical Threshold Value, exceed the objective for REC-1 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. The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies Therefore, this waterbody is being considered for placement on or removal from the CWA section 303(d) List under section 3.3 or 4.3 of the Listing Policy, as applicable, using the E. Coli objective. In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Indicator bacteria (total coliform, fecal coliform, E. coli, enterococci) populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, they do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of indicator bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address bacteria. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the list, which could result in the unnecessary expenditure of public resources or missing a human health problem. Historic lines of evidence for data collected prior to 2010 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. For E. Coli data, Listing Policy sections 3.3 and 4.3 instructs to use the binomial distribution table in sections 3.2 and 4.2, as applicable. To use the binomial table that uses a four percent exceedance frequency, the data must be collected from coastal beaches or inland surface waters from April 1 through October 31 only, and where collected from inland waters from April 1 through October 31 only, bacterial measurements must be indicative of human fecal matter, and there is substantial human contact in the waterbody.

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

State Board Review of Regional Board Conclusion and Recommendation:	The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) contains two bacteria water quality objectives applicable to the REC-1 beneficial use, which were adopted on August 7, 2018. Because the salinity level of this waterbody is equal to or less than 1 part per thousand 95 percent or more of the time, the E. coli bacteria objective applies Therefore, this waterbody is being considered for placement on or removal from the CWA section 303(d) List under section 3.3 or 4.3 of the Listing Policy, as applicable, using the E. Coli objective. In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Indicator bacteria (total coliform, fecal coliform, E. coli, enterococci) populations may fluctuate substantially on a daily, seasonal, or yearly basis. Lacking constant inputs, they do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of indicator bacteria in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Additionally, water quality conditions in waterbodies may change as a result of management actions that have been implemented to address bacteria. Unrepresentative data may result in incorrectly placing or not placing a water body segment on the list, which could result in the unnecessary expenditure of public resources or missing a human health problem. Historic lines of evidence for data collected prior to 2010 were evaluated pursuant to these considerations and were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. For E. Coli data, Listing Policy sections 3.3 and 4.3 instructs to use the binomial distribution table in sections 3.2 and 4.2, as applicable. To use the binomial table that uses a four percent exceedance frequency, the data must be collected from coastal beaches or inland surface waters from April 1 through October 31 only, and where collected from inland waters from April 1 through October 31 only, bacterial measurements must be indicative of human fecal matter, and there is substantial human contact in the waterbody.

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 127020, Indicator Bacteria	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72212

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 Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 2 of 12 samples exceed the criterion for Escherichia coli.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 Tulare Lake Basin Second Edition. rev. Jan 2004

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 Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 127020, Indicator Bacteria	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

194415

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and the results are as follows: 6 of the 88 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 544WSAWAV

Temporal Representation:

The samples were collected between the days of 2010-09-07 and 2018-09-18 .

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 127020, Indicator Bacteria	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72191

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:

SWAMP data indicates that 0 of the sample results exceed the evaluation guideline value for Escherichia coli.

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The U.S. EPA recommended objective for a 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 was collected at one monitoring site [ Walthall Slough - 544SJC002]

Temporal Representation:

Data was collected on 5/19/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	118917	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	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. Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the 16 samples exceed the Criteria for Cold Freshwater Habitat in the dissolved fraction. Zero of the 16 samples exceed the objective for Municipal & Domestic Supply in the dissolved fraction. Zero of the 16 samples exceed the objective for Municipal & Domestic Supply in the total fraction Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 16 samples exceed the Criteria for Cold Freshwater Habitat in the dissolved fraction. Zero of the 16 samples exceed the objective for Municipal & Domestic Supply in the dissolved fraction. Zero of the 16 samples exceed the objective for Municipal & Domestic Supply in the total fraction. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118917, Lead	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190863

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118917, Lead	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190688

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118917, Lead	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190927

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118918	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status. Six lines of evidence are available in the administrative record to assess this pollutant. Zero of the 12 and zero of thirteen samples exceed each of the COM and MUN, zero of thirteen samples exceed for COLD, and zero of twelve samples exceed for WARM water Quality Objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 12 and zero of thirteen samples exceed each of the COM and MUN, zero of thirteen samples exceed for COLD, and zero of twelve samples exceed for WARM water Quality Objective, and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118918, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72256

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The HCH, Gamma (Lindane) for the protection of human health from the consumption of organisms only is 0.063 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118918, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72255

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118918, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72257

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The gamma-HCH (Lindane) criterion maximum concentration to protect aquatic life in freshwater is 0.95 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118918, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190021

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The BHC, gamma(Lindane) criteria for the protection of human health from the consumption of organisms only is 0.063 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118918, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190321

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The gamma-BHC (Lindane) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118918, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

190000

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:

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118919	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 72258 has been replaced by LOE 221883 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118919, Linuron	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191108

Pollutant:

Linuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Linuron. 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:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118919, Linuron	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

221883

Pollutant:

Linuron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_SJCDWQC data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Linuron. Although a total of 12 samples were collected, 12 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2009-01-13 to 2009-12-08

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	118920	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of zero samples exceed the evaluation guideline. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of zero samples exceed the evaluation guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118920, Malathion	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72259

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." Aquatic life should not be affected unacceptably if the 4-day average concentration of Malathion, 0.028 ug/L, is not exceeded more than once every three years on the average (UC Davis Aquatic Life Criterion).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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 118920, Malathion	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191215

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 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:

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

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118939	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. LOE 72004 has been replaced by LOE 222074 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118939, Methidathion	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191312

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118939, Methidathion	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

222074

Pollutant:

Methidathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	118935	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118935, Methiocarb	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

221969

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

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 118935, Methiocarb	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191353

Pollutant:

Methiocarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118936	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of the 45 samples exceed the objective for Cold Freshwater Habitat. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 45 samples exceed the objective for Cold Freshwater Habitat and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118936, Methomyl	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191483

Pollutant:

Methomyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The Basin Plan states: \Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide...\" The criteria continuous concentration for Methomyl in the San Joaquin River system is 0.5 ug/L (4-day average). "

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118921	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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:	Data for this waterbody has been considered; however, there is insufficient information to determine beneficial use support for the large and complex Delta subarea. Decisions regarding the Delta subareas will be phased out of the Integrated Report during future cycles and data will be reevaluated as part of localized assessments where data is more representative of water quality in the described segment. Due to this change, new decisions for the Delta subareas will not be assessed for the 2020/2022 cycle. Decisions regarding the beneficial use support of individual waterbodies within the Delta will be made during a future Integrated Report cycle.

Regional Board Decision Recommendation:	After review, RWQCB staff concludes that the listing decision will not change during the current cycle and the specific waterbody will be reassessed in future cycles. Assessments for Delta Subareas will be phased out of the Integrated Report during future cycles and these data will be reevaluated as part of localized assessments where data is more representative of water quality.

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 118921, Methoxychlor	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72007

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118921, Methoxychlor	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191325

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118921, Methoxychlor	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191611

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria toxicity threshold for methoxychlor for freshwater aquatic life protection is 0.03 ug/l.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118921, Methoxychlor	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72017

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the Executive Officer (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:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118922	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	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 one line(s) of evidence are necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Zero of the zero samples exceed the Criteria/Objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of zero samples exceeded Criteria/Objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118922, Methyl Parathion	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72018

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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

Guideline Reference:

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

Spatial Representation:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118922, Methyl Parathion	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

193044

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Methyl. Although a total of 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:

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

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118923	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination. The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118923, Molybdenum	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191926

Pollutant:

Molybdenum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Agricultural Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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:

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

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118924	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Eight lines of evidence are available in the administrative record to assess this pollutant. Two lines of evidence are available to assess for aquatic life. Three lines of evidence are available to assess for Municipal and Domestic Supply. Three lines of evidence are available to assess for Commercial or recreational collection of fish, shellfish, or organisms. Zero of the sixteen samples, reported as a dissolved concentration, exceed the criterion for aquatic life. Zero of the twelve samples, with the fraction not reported, exceed the criterion for aquatic life. Zero of the fifteen samples, reported as a dissolved concentration, exceed the objective for Municipal and Domestic Supply. Zero of the 27 samples, reported as a total concentration or with the fraction not reported, exceed the objective for Municipal and Domestic Supply. Zero of the fifteen samples, reported as a dissolved concentration, exceed the criterion for Commercial or recreational collection of fish, shellfish, or organisms. Zero of the 28 samples, reported as a total concentration or with the fraction not reported, exceed the criterion for Commercial or recreational collection of fish, shellfish, or organisms. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the sixteen samples, reported as a dissolved concentration, exceed the criterion for aquatic life. Zero of the 27 samples, reported as a total concentration or with the fraction not reported, exceed the objective for Municipal and Domestic Supply. Zero of the 28 samples, reported as a total concentration or with the fraction not reported, exceed the criterion for Commercial or recreational collection of fish, shellfish, or organisms. This does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118924, Nickel	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72020

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Nickel criterion for the protection of human health from consumption of organisms is 4.6 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118924, Nickel	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72019

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 Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 11 samples exceed the criterion for Nickel.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118924, Nickel	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72021

Pollutant:

Nickel

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 AgWaiver data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Nickel.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The chromium criterion in freshwater is hardness-dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness-dependent formula for metals criteria.

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 Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [ Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118924, Nickel	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191663

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Nickel criteria for the protection of human health from consumption of organisms only is 4,600 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118924, Nickel	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191867

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Sediment, Toxicity, Water data for the 2020/2022 integrated report in Region 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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118924, Nickel	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191948

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118924, Nickel	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191868

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118924, Nickel	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

191934

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Nickel criteria for the protection of human health from consumption of organisms only is 4,600 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118925	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Eight of the 96 samples exceed the objective for Municipal & Domestic Supply. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eight of the 96 samples exceed the objective for Municipal & Domestic Supply and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118925, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72022

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118925, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

192060

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:

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-09-18

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118926	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination. The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118926, Oxamyl (Vydate)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

192689

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118926, Oxamyl (Vydate)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

192670

Pollutant:

Oxamyl (Vydate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for oxamyl is the USEPA Aquatic Life Benchmark of 27 ug/L for chronic toxicity in invertebrates (7 day average).

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118941	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118941, Oxyfluorfen	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

192497

Pollutant:

Oxyfluorfen

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Oxyfluorfen is the USEPA Aquatic Life Benchmark of 0.29 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2018-01-11 and 2018-02-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118956	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available. LOE 72033 has been replaced by LOE 222310 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118956, Paraquat	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

192674

Pollutant:

Paraquat

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Paraquat. Although a total of 20 samples were collected, 20 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2018-07-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118956, Paraquat	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

222310

Pollutant:

Paraquat

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed ILRP_SJCDWQC data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Paraquat. Although a total of 12 samples were collected, 12 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2009-01-13 to 2009-12-08

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	118943	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118943, Pendimethalin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

192842

Pollutant:

Pendimethalin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, 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:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2018-01-11 and 2018-02-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	130403	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 130403, Permethrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

192958

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Permethrin. Although a total of 5 samples were collected, 5 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The chronic concentration goal for Permethrin is 1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of Permethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Permethrin

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-03-14 to 2018-08-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 130403, Permethrin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

196711

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

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 evaluation guideline for permethrin, 0.89 ug/g, is one-tenth of the median lethal concentration (LC50; 8.9 ug/g) and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin from Amweg et al. (2005).

Guideline Reference:

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

Guideline Reference:

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

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 544WSAWAV.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-07 to 2010-09-07

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118944	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. LOE 72037 has been replaced by LOE 222330 due to a reassessment of data using a U.S. EPA aquatic life benchmark.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118944, Phorate	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

193154

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118944, Phorate	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

222330

Pollutant:

Phorate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	118947	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the fifty-five samples exceed the evaluation guideline for COLD. LOE 72046 has been replaced by LOE 222296 due to a reassessment of data using a U.S. EPA aquatic life benchmark. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the fifty-five samples exceed the evaluation guideline for COLD and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118947, Phosmet	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

222296

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

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 118947, Phosmet	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

193258

Pollutant:

Phosmet

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118933	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:

Line of Evidence (LOE) for Decision ID 118933, Pyrethroids	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

197021

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

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 evaluation guideline for the protection of aquatic life from pyrethroids is one toxic unit equivalent. A toxic unit equivalent is equal to the sum of; Bifenthrin, Cyfluthrin, Cypermethrin, Lambda-Cyhalothrin, and Permethrin, each having their reported concentration divided their respective evaluation guideline prior to being summed. If this results in a value greater than one, the sample day is considered to be in exceedance of the water quality standard. (Department of Fish and Game Aquatic Life Criteria for Pyrethroid Insecticides, 2000)

Guideline Reference:

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

Guideline Reference:

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

Guideline Reference:

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

Guideline Reference:

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

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: ll. Pyrethroid insecticides. Reviews of Environmental Contamination and Toxicology 216:51-103.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 544WSAWAV.

Temporal Representation:

Data for this waterbody were collected over the date range 2010-09-07 to 2010-09-07

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118933, Pyrethroids	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

193391

Pollutant:

Pyrethroids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Pyrethroids. Although a total of 7 samples were collected, 7 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

The summed ratios of the pyrethroid pesticides bifenthrin, cyfluthrin, cypermethrin, esfenvalerate, lambda-cyhalothrin, permethrin and their respective chronic concentration goals are not to exceed 1. If the freely dissolved concentrations of these pesticides were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2018-02-20 to 2018-09-18

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118928	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118928, Selenium	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72047

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.005 mg/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118928, Selenium	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

193269

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118928, Selenium	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

193356

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118928, Selenium	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72048

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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 Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118929	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). LOE 72049 has been replaced by LOE 222469 due to a reassessment of data using a U.S. EPA aquatic life benchmark. The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118929, Simazine	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

222469

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

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 118929, Simazine	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

193680

Pollutant:

Simazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Simazine is the USEPA Aquatic Life Benchmark of 6 ug/L for a nonvascular plant (acute).

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118929, Simazine	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

193412

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118929, Simazine	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72050

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	127544	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Three of the 85 samples, reported as a total concentration or with the fraction not reported, exceed the water quality objective for MUN. 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. Three of the 85 samples, reported as a total concentration or with the fraction not reported, exceeded the water quality objective for MUN, 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 decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 127544, Specific Conductivity	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72187

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 Ag Waiver data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 2 of 13 samples exceed the criterion for Conductivity(Us).

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California secondary maximum contaminant levels for electrical conductivity provide a range of values including a recommended level (900 uS/cm), an upper level (1,600 uS/cm) and a short-term level (2,200 uS/cm). The recommended level of 900 uS/cm was used as it is protective of all drinking water uses.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 127544, Specific Conductivity	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

230000

Pollutant:

Specific Conductivity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

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 in the Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin for specific conductance is 900 uS/cm.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2016-09-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 127544, Specific Conductivity	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72186

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:

SWAMP data indicates that 0 of the sample results exceed the criterion for electrical conductivity.

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Secondary Maximum Contaminant Levels for electrical conductivity provide a range of values including a recommended level (900 uS/cm), an upper level (1,600 uS/cm) and a short-term level (2,200 uS/cm). The recommended level of 900 uS/cm was used as it is protective of all drinking water uses.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

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

Guideline Reference:

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

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Walthall Slough - 544SJC002]

Temporal Representation:

Data was collected on 5/19/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	123059	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess this pollutant. Pursuant to section 6.1.5.9 of the Listing Policy, this assessment utilized the upper limit of the optimal temperature range for rainbow trout for growth and completion of most life stages to interpret the narrative water quality objective for temperature. 29 of 92 samples exceeded the evaluation guideline for COLD. 21 of 71 samples exceeded the evaluation guideline for Fish Migration and Fish Spawning. However, the available data are insufficient to satisfy the Listing Policy requirements for spatial and temporal representation (sections 6.1.5.2 and 6.1.5.3). The surface water grab samples collected did not provide sufficient temporal and spatial representation to determine if temperature conditions experienced by aquatic life were within the optimal temperature range throughout the entire water column or the length of time temperature conditions may have exceeded the optimal temperature range. Available information for this waterbody-pollutant combination is insufficient to determine whether the aquatic beneficial use is supported. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available for this Integrated Report cycle indicating that standards are not met. However, the exceedances of the evaluation guideline indicate that beneficial uses may be threatened. This decision will be reevaluated in the next Integrated Report cycle as more data and information become available. Additional data and information may include information demonstrating that sample location(s) are representative of conditions throughout the waterbody, data from additional sampling locations, continuous monitoring data collected in the waterbody, waterbody-specific information on sensitive resident species, their life stage time frames, and the appropriate temperature thresholds necessary to support each life stage.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 123059, Temperature, water	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

230988

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Inland Fishes of California

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2016-09-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 123059, Temperature, water	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

230989

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Fish Migration

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, 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:

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

Guideline Reference:

Inland Fishes of California

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2016-09-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 123059, Temperature, water	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

230990

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, 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:

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

Guideline Reference:

Inland Fishes of California

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2016-09-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 123059, Temperature, water	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72061

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 7 of 20 samples exceed the criterion for Water Temperature.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

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

Guideline Reference:

Inland Fishes of California (1976)

Spatial Representation:

Data for this line of evidence for Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-7/13/2010.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 123059, Temperature, water	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72060

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that the sample result exceeds the evaluation guideline value for Water Temperature.

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

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

Guideline Reference:

Inland Fishes of California (1976)

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Walthall Slough - 544SJC002]

Temporal Representation:

Data was collected on 5/19/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	118931	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118931, Toxaphene	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

193808

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Toxaphene. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0002 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118931, Toxaphene	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

193978

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Toxaphene. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 consumption of organisms only is 0.00075 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118931, Toxaphene	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72077

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Toxaphene criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0002 ug/L. (California Toxics Rule, 2000)

Objective/Criterion Reference:

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118931, Toxaphene	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72063

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:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118931, Toxaphene	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

194167

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 San Joaquin County Delta Water Quality Coalition data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Toxaphene. Although a total of 6 samples were collected, 6 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and 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 (544WSAWAV).

Temporal Representation:

Date for this waterbody was collected over the date range 2010-09-07 to 2015-12-08

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118931, Toxaphene	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72064

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Ag Waiver data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Toxaphene. Twelve samples were not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Toxaphene criterion for the protection of human health from consumption of organisms only is 0.00075 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.


DECISION ID	118932	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). LOE 72078 has been replaced by LOE 222523 due to a reassessment of data using a U.S. EPA aquatic life benchmark. The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118932, Trifluralin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

194237

Pollutant:

Trifluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Trifluralin is the USEPA Aquatic Life Benchmark of 1.9 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2017-09-19

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118932, Trifluralin	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

222523

Pollutant:

Trifluralin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

The evaluation guideline for Trifluralin is the USEPA Aquatic Life Benchmark of 1.9 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2009-01-13 and 2009-12-08

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	128067	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Zero samples exceeded the objectives, guidelines, or criteria for beneficial uses applicable to this water segment-pollutant combination, which is less than the minimum number of exceedances needed to place the water segment on the section CWA section 303(d) List for toxicants (Table 3.1 of the Listing Policy). The data used satisfies the data quality requirements (section 6.1.4) and data quantity requirements (section 6.1.5) of the Listing Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

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

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 128067, Zinc	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

221033

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 Basin Plan objective for zinc in this water body is 0.016 mg/L expressed as a 7 day averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

SJCDWQC_QAPP_082508_Rev102010_Amended06162015_withSignatures_NoSOPs_Final.pdf, 2017-1227 QAPP AmdmtAprvlNewAnalytes.pdf, 2018-0423 SJD QAPPaprvl.pdf, ESJ_Delta_QAPP_Amend_Approval.pdf, FieldQC_QAPP_Amend_030218.pdf, ILRP_SJC_QAPP_Amendt_SedLabChangeWsigs.pdf, SJCDWQC_QAPP_Amendment_Sampling SOP.pdf, SJD QAPP AmdmtFildQualContrSamplReqmntSigned.pdf

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 128067, Zinc	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72080

Pollutant:

Zinc

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 AgWaiver data for Walthall Slough (in Delta Waterways, eastern portion) to determine beneficial use support and results are as follows: 0 of 12 samples exceed the criterion for Zinc.

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [ Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 128067, Zinc	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72079

Pollutant:

Zinc

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 San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The California secondary maximum contaminant level for zinc is 5.0 mg/L.

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walthall Slough (in Delta Waterways, eastern portion) was collected at 1 monitoring site [Walthal Slough @ Woodward Ave - 544WSAWAV]

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 128067, Zinc	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

221020

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 Basin Plan objective for zinc in this water body is 0.1 mg/L expressed as a 7 day averaging period.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2013-12-17

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118905	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

Pollutant:	alpha-Endosulfan (Endosulfan 1)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. Six lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 and zero of eight samples exceed the water quality objective for each of the COM, MUN, and WARM beneficial uses. 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. Zero of 12 and zero of eight samples exceed the water quality objective for each of the COM, MUN, and WARM beneficial uses. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118905, alpha-Endosulfan (Endosulfan 1)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72093

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endosulfan I criterion for the protection of human health from consumption of organisms only is 240 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118905, alpha-Endosulfan (Endosulfan 1)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72092

Pollutant:

alpha-Endosulfan (Endosulfan 1)

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 San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endosulfan I criterion for the protection of human health from consumption of water and organisms is 110 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118905, alpha-Endosulfan (Endosulfan 1)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72094

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endosulfan I criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118905, alpha-Endosulfan (Endosulfan 1)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189223

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endosulfan I criteria for the protection of human health from consumption of organisms only is 240 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-08-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118905, alpha-Endosulfan (Endosulfan 1)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189280

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endosulfan I criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.028 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-08-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118905, alpha-Endosulfan (Endosulfan 1)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189144

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-08-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	118927	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

Pollutant:	beta-Endosulfan (Endosulfan 2)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. Six lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 and zero of eight samples exceed the water quality objective for each of the COM, MUN, and WARM beneficial uses. 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. Zero of 12 and zero of eight samples exceed the water quality objective for each of the COM, MUN, and WARM beneficial uses. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 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 decision was made by SWRCB staff.

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 118927, beta-Endosulfan (Endosulfan 2)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72121

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endosulfan II criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118927, beta-Endosulfan (Endosulfan 2)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189341

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 (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-08-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118927, beta-Endosulfan (Endosulfan 2)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189396

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endosulfan II criteria for the protection of human health from consumption of organisms only is 240 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-08-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 118927, beta-Endosulfan (Endosulfan 2)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72122

Pollutant:

beta-Endosulfan (Endosulfan 2)

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 San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The beta-endosulfan criterion for the protection of human health from consumption of water and organisms is 110 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118927, beta-Endosulfan (Endosulfan 2)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72123

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Data for Various Pollutants in San Joaquin and Delta Water Quality Coalition, 2004-2010.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Endosulfan II criterion for the protection of human health from consumption of organisms only is 240 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:

Temporal Representation:

Data was collected over the time period 1/13/2009-12/8/2009.

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):

Quality Assurance Project Plan for Monitoring by the San Joaquin County and Delta Water Quality Coalition.

Line of Evidence (LOE) for Decision ID 118927, beta-Endosulfan (Endosulfan 2)	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

189470

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endosulfan II criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.028 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2018-08-21

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition


DECISION ID	123058	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Seven lines of evidence are available in the administrative record to assess this pollutant. Zero of the 72 samples exceeded the OBJECTIVE for COLD and REC-1. Zero of the 71 samples exceeded the OBJECTIVE for REC-2. Zero of the 1 samples exceeded the OBJECTIVE for MUN. One of the 8 samples exceeded the OBJECTIVE for WARM. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of the 72 samples exceeded the OBJECTIVE for COLD and REC-1. Zero of the 71 samples exceeded the OBJECTIVE for REC-2, and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. Zero of the 1 samples exceeded the OBJECTIVE for MUN. One of the 8 samples exceeded the OBJECTIVE for WARM. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 123058, pH	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72036

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the criterion for pH.

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Walthall Slough - 544SJC002]

Temporal Representation:

Data was collected on 5/19/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 123058, pH	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72035

Pollutant:

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:

SWAMP data indicates that 0 of the sample results exceed the criterion for pH.

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Walthall Slough - 544SJC002]

Temporal Representation:

Data was collected on 5/19/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 123058, pH	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

23234

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 East San Joaquin Water Quality Coalition collected 8 samples from April 2003 to September 2003. One out of 8 samples was outside the acceptable range; the sample was 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

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:

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 Walthal Slough at Woodward Avenue.

Temporal Representation:

Sampling occurred from April 2003 to September 2003.

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 123058, pH	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

228718

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2016-09-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 123058, pH	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

229510

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Non-Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2016-09-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 123058, pH	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

228804

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Central Valley Region Sacramento River Basin and San Joaquin River Basin: pH should not be lower than 6.5 or higher than 8.5.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (544WSAWAV)

Temporal Representation:

The samples were collected between the dates of 2010-09-07 and 2016-09-20

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 2.0)

QAPP Information Reference(s):

Quality Assurance Project Plan For Monitoring By The San Joaquin County & Delta Water Quality Coalition (Revision 3.0)

QAPP Information Reference(s):

Quality Assurance Project Plan for Monitoring By the San Joaquin County & Delta Water Quality Coalition

Line of Evidence (LOE) for Decision ID 123058, pH	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72034

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that 0 of the sample results exceed the criterion for pH.

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Walthall Slough - 544SJC002]

Temporal Representation:

Data was collected on 5/19/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan


DECISION ID	128853	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

Pollutant:	Oxygen, Dissolved
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2035
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Eight lines of evidence are available in the administrative record to assess this pollutant for aquatic life and for Fish Spawning (SPWN). Seventy-six of the 149 samples exceed the objective for aquatic life. Seventy-one of the 141 samples exceed the objective for SPWN. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Seventy-six of the 149 samples exceed the objective for aquatic life. Seventy-one of the 141 samples exceed the objective for SPWN. This exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	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 128853, Oxygen, Dissolved	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72031

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that the sample result exceeds the criterion for Oxygen, Dissolved.

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data for this line of evidence was collected at one monitoring site [ Walthall Slough - 544SJC002]

Temporal Representation:

Data was collected on 5/19/2009.

Environmental Conditions:

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

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 128853, Oxygen, Dissolved	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

59511

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

The sample collected exceeded the objective.

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved oxygen concentrations shall not be reduced below the following minimum levels at any time: Waters designated COLD 7.0 mg/l

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One sample was collected from the Walthall Slough station (544SJC002).

Temporal Representation:

One sample was collected on 5/19/2009.

Environmental Conditions:

QAPP Information:

SWAMP QAPP

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 128853, Oxygen, Dissolved	Region 5
Walthall Slough (in Delta Waterways, eastern portion)

LOE ID:

72032

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

SWAMP data indicates that the sample result exceeds the criterion for Oxygen, Dissolved.

Data Reference: