Final California 2018 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name: Walthall Slough (in Delta Waterways, eastern portion)
Water Body ID: CAR5440000020080818111435
Water Body Type: River & Stream
 
DECISION ID
89874
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
Pollutant: Aldicarb
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 12 samples exceed each of the MUN and WARm and COM water 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 the 12 samples exceed each of the MUN and WARM water 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 89874, Aldicarb
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72073
 
Pollutant: Aldicarb
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for aldicarb, 6.33 ug/L, is one-tenth of the median lethal concentration (LC50 = 63.3 ug/L) for Lepomis macrochirus (Bluegill sunfish); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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 89874, 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: 12
Number of Exceedances: 0
 
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.
 
 
DECISION ID
89875
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the zero samples exceed each of the COM and MUN, zero of the 12 samples exceed the 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 zero samples exceed each of the COM and MUN, zero of the 12 sample exceed the 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: 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 89875, 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: 0
Number of Exceedances: 0
 
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.
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: 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 89875, 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: 0
Number of Exceedances: 0
 
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: 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 89875, 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: 12
Number of Exceedances: 0
 
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 Aldrin.
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: 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.
 
 
DECISION ID
84434
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
Pollutant: Arsenic
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
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.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 samples exceed the water quality objective for each of the 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 samples exceed the water quality objective for each of the 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: 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 84434, Arsenic
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72105
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Arsenic.
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 arsenic is 0.010 mg/L.
Objective/Criterion Reference: Maximum Contaminant Levels for organic and inorganic chemicals. CCR Title 22
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for 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 84434, Arsenic
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72106
 
Pollutant: Arsenic
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Arsenic.
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 dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 0.150 mg/L (California Toxics Rule, 2000).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for 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
84435
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)(2016)
Revision Status Original
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.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 samples exceed the MUN water quality objective and zero of 12 samples exceed the WARM 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 12 samples exceed the MUN water quality objective and zero of 12 samples exceed the WARM evaluation guideline. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is 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 84435, Atrazine
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72107
 
Pollutant: Atrazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Atrazine.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Atrazine, 43 ug/L, is a an EC50 for Lemna gibba (duckweed); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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 84435, 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: 12
Number of Exceedances: 0
 
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 Atrazine.
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: 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.
 
 
DECISION ID
89877
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 89877, 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: 0
Number of Exceedances: 0
 
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 Azinphos methyl.
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 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: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
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.
 
 
DECISION ID
84436
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)(2016)
Revision Status Original
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.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 samples exceed each of the MUN and WARM water quality objectives.

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 samples exceed each of the MUN and WARM water quality objectives. 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 84436, 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: 12
Number of Exceedances: 0
 
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 84436, 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: 12
Number of Exceedances: 0
 
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 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 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
84481
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)(2016)
Revision Status Original
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 12 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 12 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 84481, 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: 12
Number of Exceedances: 0
 
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 Carbaryl.
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 USEPA recommended water quality criterion for freshwater aquatic life for carbaryl is 2.1 µg/L.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
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.
 
 
DECISION ID
89933
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 12 samples exceed the MUN water quality objective, zero of the 12 samples exceed the WARM water 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 12 samples exceed the MUN water quality objective, zero of 12 samples exceed the WARM water 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 89933, 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: 12
Number of Exceedances: 0
 
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 Carbofuran.
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: 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 89933, 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: 12
Number of Exceedances: 0
 
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 Carbofuran.
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 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: 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.
 
 
DECISION ID
84483
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)(2016)
Revision Status Original
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 12 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 12 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 84483, 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: 12
Number of Exceedances: 0
 
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 Chlorpyrifos.
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 freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000).
Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game (with minor corrections to significant figures as described in Beaulaurier et al., 2005).
 
Spatial Representation: Data for this line of evidence for 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.
 
 
DECISION ID
84484
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
Pollutant: Copper
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
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.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 samples exceed each of the MUN and WARM water quality objectives.

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 samples exceed each of the MUN and WARM water quality objectives 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 84484, Copper
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72153
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Copper.
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 copper is 1.0 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 84484, Copper
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72154
 
Pollutant: Copper
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Copper.
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.
 
 
DECISION ID
89990
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 12 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 12 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 89990, 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: 12
Number of Exceedances: 0
 
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 Cyanazine.
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 EC50 for Navicula pelliculosa (freshwater diatom) for cyanazine is 4.8 ug/L (USEPA Office of Pesticide Programs Ecotoxicity database).
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
84527
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)(2016)
Revision Status Original
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 12 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 12 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 84527, 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: 12
Number of Exceedances: 0
 
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 Diazinon.
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 freshwater chronic criterion value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).
Guideline Reference: Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game
 
Spatial Representation: Data for this line of evidence for 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.
 
 
DECISION ID
89992
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 12 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 12 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 89992, Dicofol
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72157
 
Pollutant: Dicofol
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Dicofol.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Dicofol, 5.9 ug/L, is the maximum acceptable toxicicant concentration (MATC) for Oncorhyncus mykiss (Rainbow trout); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
83884
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the zero samples exceed each of the COLD and MUN, zero of the 12 samples exceed the 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 zero samples exceed each of the COLD and MUN, zero of the 12 samples exceed the 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: 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 83884, 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: 0
Number of Exceedances: 0
 
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: 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 83884, 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: 0
Number of Exceedances: 0
 
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.
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: 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 83884, 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: 12
Number of Exceedances: 0
 
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 Dieldrin.
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: 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.
 
 
DECISION ID
84528
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)(2016)
Revision Status Original
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 12 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 12 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 84528, Dimethoate
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72171
 
Pollutant: Dimethoate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Dimethoate.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for dimethoate, 4.3 ug/L, is one-tenth of the median lethal concentration (LC50 = 43 ug/L) for Pteronarcys californica (Stonefly); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
89989
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 12 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 12 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 89989, 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: 12
Number of Exceedances: 0
 
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 Disulfoton.
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 USEPA National Recommended Water Quality criterion for disulfoton in freshwater (0.05 ug/L) is an aquatic life maximum (instantaneous) level.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
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.
 
 
DECISION ID
90108
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the 12 samples exceed each of the COM, MUN, and 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 samples exceed each of the COM, MUN, and 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: 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 90108, 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: 12
Number of Exceedances: 0
 
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 Endrin.
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: 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 90108, 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: 12
Number of Exceedances: 0
 
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 Endrin.
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: 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 90108, 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: 12
Number of Exceedances: 0
 
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 Endrin.
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: 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.
 
 
DECISION ID
84529
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)(2016)
Revision Status Original
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.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 samples exceed the MUN water quality objective and zero of 12 samples exceed the WARM 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 12 samples exceed the MUN water quality objective and zero of 12 samples exceed the WARM evaluation guideline. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is 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 84529, Glyphosate
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72213
 
Pollutant: Glyphosate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Glyphosate.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for glyphosate, 5,500 ug/L, is one-tenth of the median lethal concentration (LC50 = 55,000 ug/L) for Chironimus plumosus (Midge). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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 84529, 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: 12
Number of Exceedances: 0
 
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 Glyphosate.
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: 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.
 
 
DECISION ID
76692
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the zero samples exceed each of the COM, MUN, and 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 zero samples exceed each of the COM, MUN, and 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: 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 76692, 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: 0
Number of Exceedances: 0
 
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.
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: 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 76692, 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: 0
Number of Exceedances: 0
 
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: 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 76692, 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: 0
Number of Exceedances: 0
 
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.
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: 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.
 
 
DECISION ID
90047
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the zero samples exceed each of the COM, MUN, and 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 zero samples exceed each of the COM, MUN, and 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: 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 90047, 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: 0
Number of Exceedances: 0
 
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.
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: 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 90047, 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: 0
Number of Exceedances: 0
 
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: 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 90047, 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: 0
Number of Exceedances: 0
 
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.
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: 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.
 
 
DECISION ID
70860
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 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. Two of the 13 water samples exceed the evaluation guideline for E. coli and one of these water samples analyzed for total coliform did not exceed the evaluation guideline for total coliform.

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. Two of the 13 water samples exceed the evaluation guideline for E. coli and one of these water samples analyzed for total coliform did not exceed the evaluation guideline for total coliform, and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 3.2.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 70860, 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: 12
Number of Exceedances: 2
 
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 70860, 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: 1
Number of Exceedances: 0
 
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: RWB5 Bacti Source ID FY0809
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The 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
84530
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)(2016)
Revision Status Original
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 12 samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Zero of 12 samples exceed the water quality objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 84530, Lead
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72240
 
Pollutant: Lead
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Lead.
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.
 
 
DECISION ID
90048
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of the 12 samples exceed each of the COM, MUN, and 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 samples exceed each of the COM, MUN, and 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: 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 90048, 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: 12
Number of Exceedances: 0
 
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 HCH, gamma.
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: 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 90048, 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: 12
Number of Exceedances: 0
 
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 HCH, gamma.
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: 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 90048, 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: 12
Number of Exceedances: 0
 
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 HCH, gamma.
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: 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.
 
 
DECISION ID
90049
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 12 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 12 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 90049, Linuron
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72258
 
Pollutant: Linuron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Linuron.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Linuro, 13.7 ug/L, is the EC50 for Navicula pelliculosa (freshwater diatom). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
84570
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)(2016)
Revision Status Original
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 84570, 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: 0
Number of Exceedances: 0
 
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 Malathion.
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 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: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
90050
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 12 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 12 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 90050, Methidathion
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72004
 
Pollutant: Methidathion
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Methidathion.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Methidathion, 0.86 ug/L, is the maximum acceptable toxicicant concentration (MATC) for Daphina magna (Water flea); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
90110
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 12 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 12 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 90110, Methiocarb
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72005
 
Pollutant: Methiocarb
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Methiocarb.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for methiocarb, 43.6 ug/L, is one-tenth of the median lethal concentration (LC50 = 436 ug/L) for Oncorhyncus mykiss (Rainbow trout); USEPA Office of Pesticide Programs Ecotoxicity database.
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
84571
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)(2016)
Revision Status Original
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 12 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 12 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 84571, Methomyl
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72006
 
Pollutant: Methomyl
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Methomyl.
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 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). (CDFG, 1996)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
90111
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 12 samples exceed each of the MUN and 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 12 samples exceed each of the MUN and WARM water quality objectives 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 90111, 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: 12
Number of Exceedances: 0
 
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 Methoxychlor.
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: 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 90111, 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: 12
Number of Exceedances: 0
 
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 Methoxychlor.
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: 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.
 
 
DECISION ID
90168
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 90168, 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: 0
Number of Exceedances: 0
 
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 Parathion, Methyl.
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 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: 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.
 
 
DECISION ID
84900
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)(2016)
Revision Status Original
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.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 samples exceed the water quality objective for each of the COMM and WARM beneficial uses and zero of 11 samples 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 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 samples exceed the water quality objective for each of the COMM and WARM beneficial uses and zero of 11 samples exceed the water quality objective for MUN. 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 84900, 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: 12
Number of Exceedances: 0
 
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 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 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 84900, 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: 12
Number of Exceedances: 0
 
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 84900, 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: 11
Number of Exceedances: 0
 
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.
 
 
DECISION ID
92258
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of twelve samples exceed the California Primary MCL 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. Zero of twelve samples exceed the California Primary MCL for MUN 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 92258, 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: 12
Number of Exceedances: 0
 
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 Nitrate/Nitrite as N.
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.
 
 
DECISION ID
72039
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
Pollutant: Oxygen, Dissolved
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

Four lines of evidence is available in the administrative record to assess this pollutant. Two of the two samples exceed the COLD, one of the one samples exceed the Fish Spawning, four of the seven samples exceed the WARM water quality objective.

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. Two of the two samples exceed the COLD, one of the one samples exceed the Fish Spawning, four of the seven samples exceed the WARM water quality objective, and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 72039, 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: 1
Number of Exceedances: 1
 
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: RWB5 Bacti Source ID FY0809
 
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: 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 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 72039, Oxygen, Dissolved
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 23232
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 4
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Seven samples were taken from Walthal Slough during 2003 and 2006. Five of the seven samples fell below the Water Quality Objective for minimum dissolved oxygen content in surface water (5 mg/l).
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: Within the legal boundaries of the Delta, the dissolved oxygen concentration shall not be reduced below: 7.0 mg/l in the Sacramento River (below the I Street Bridge) and in all Delta waters west of the Antioch Bridge; 6.0 mg/l in the San Joaquin River (between Turner Cut and Stockton, 1 September through 30 November); and 5.0 mg/l in all other Delta waters except for those bodies of water which are constructed for special purposes and from which fish have been excluded or where the fishery is not important as a beneficial use.
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 Walthall Slough at Woodward Avenue in San Joaquin County.
Temporal Representation: Samples were collected between April and December 2003. Samples were collected at bi-monthly and monthly intervals.
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 72039, 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: 1
Number of Exceedances: 1
 
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: RWB5 Bacti Source ID FY0809
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The minimum dissolved oxygen concentration for waters designated as SPWN is 7.0 mg/L. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin Basin)
Objective/Criterion Reference: 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 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 72039, 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: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The sample collected exceeded the objective.
Data Reference: RWB5 Bacti Source ID FY0809
 
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: 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: 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
 
 
DECISION ID
84947
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)(2016)
Revision Status Original
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 12 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 12 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 84947, Paraquat
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72033
 
Pollutant: Paraquat
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Paraquat.
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 evaluation guideline for Oryzalin, 1,200 ug/L, is an EC50 for Daphnia sp. (Water flea). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
89709
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 12 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 12 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 89709, Phorate
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72037
 
Pollutant: Phorate
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Phorate.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for phorate, 0.2 ug/L, is one-tenth of the median lethal concentration (LC50 = 2.0 ug/L) for Lepomis macrochirus (Bluegill sunfish). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
89710
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a 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 12 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 12 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 89710, Phosmet
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72046
 
Pollutant: Phosmet
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Phosmet.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Phosmet, 5.6 ug/L, is the EC50 for Daphnia magna (Water flea). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
92261
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of twelve samples exceed the California Primary MCL for MUN, and 0 of 12 samples exceed the criterion continuous concentration to protect aquatic life in freshwater (California Toxics Rule, 2000) 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 twelve samples exceed the California Primary MCL for MUN, and 0 of 12 samples exceed the criterion continuous concentration to protect aquatic life in freshwater (California Toxics Rule, 2000) for WARM 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 92261, 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: 12
Number of Exceedances: 0
 
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 Selenium.
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.
 
Line of Evidence (LOE) for Decision ID 92261, 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: 12
Number of Exceedances: 0
 
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 Selenium.
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.
 
 
DECISION ID
84989
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)(2016)
Revision Status Original
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.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 samples exceed the MUN water quality objective and zero of 12 samples exceed the WARM 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 12 samples exceed the MUN water quality objective and zero of 12 samples exceed the WARM evaluation guideline. This sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is 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 84989, Simazine
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72049
 
Pollutant: Simazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Simazine.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Simazine, 90 ug/L, is the EC50 for Navicula pelliculosa (freshwater diatom). (USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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 84989, 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: 12
Number of Exceedances: 0
 
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 Simazine.
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: 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.
 
 
DECISION ID
90230
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 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. Two of the 14 samples exceed the water quality objective.

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. Two of 14 samples exceed the water quality objectives and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 3.2.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 90230, 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: 13
Number of Exceedances: 2
 
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 90230, 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: 1
Number of Exceedances: 0
 
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: RWB5 Bacti Source ID FY0809
 
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: 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: 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
100310
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification for placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that:

1. The data used satisfy the data quality requirements of section 6.1.4 of the Listing Policy.

2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Listing Policy. To determine the appropriate use support rating for COLD, an evaluation guideline identifying the optimal temperature range for rainbow trout for growth and completion of most life stages was used to interpret the narrative water quality objective for temperature. Section 6.1.5.2 of the Listing Policy states ¿¿samples should represent statistically or in a targeted manner the segment of the water body.¿ Water temperature data collected for this water body do not capture the spatial variability of temperatures experienced by aquatic life. Section 6.1.5.3 of the Listing Policy states ¿Samples should be representative of the critical timing that the pollutant is expected to impact the water body.¿ Water temperature data collected for this water body do not capture the temporal variability of temperatures experienced by aquatic life. Per Section 6.1.5.9 of the Listing Policy, ¿¿temperature monitoring data shall be compared to the temperature requirements of aquatic life living in the water segment.¿

Currently, the readily available data for water temperature in this segment are insufficient to determine whether growth and all life stages of rainbow trout are being supported. The monitoring programs that generated the temperature data were not designed to evaluate attainment of temperature standards to support aquatic life. The surface water grab samples collected do not provide sufficient temporal and spatial representation of temperature conditions throughout the water body segment for fish exposure.

3. 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 100310, 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: 1
Number of Exceedances: 1
 
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: RWB5 Bacti Source ID FY0809
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. (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: 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
 
Line of Evidence (LOE) for Decision ID 100310, 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: 20
Number of Exceedances: 7
 
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: 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 Juoaquin River Basin Plans).
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.
 
 
DECISION ID
89769
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a one line(s) of evidence are necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of zero samples exceed the water quality objectives for neither COMM, MUN, nor 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 zero samples exceed the water quality objectives for neither COMM, MUN, nor WARM 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 89769, 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: 0
Number of Exceedances: 0
 
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: 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 89769, 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: 0
Number of Exceedances: 0
 
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.
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: 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 89769, 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: 0
Number of Exceedances: 0
 
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.
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: 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.
 
 
DECISION ID
73260
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
Pollutant: Toxicity
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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.

Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. None of 7 samples exceeded the water quality objective for ceriodaphnia and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. In addition, none of 8 samples exceeded the water quality objective for fathead minnow 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: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 73260, Toxicity
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 23231
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 7
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Zero of the 7 samples tested with Ceriodaphnia dubia were toxic and violated the narrative toxicity objective.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CVRWQCB, 2007)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Statistically significant difference from control using a t-test with 4-day acute-style toxicity tests.
Guideline Reference: Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-012
 
Spatial Representation: Samples were collected from Walthal Slough at Woodward Avenue.
Temporal Representation: Samples were collected from April 2003 to September 2003.
Environmental Conditions:
QAPP Information: Data quality: Excellent. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 73260, Toxicity
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 23233
 
Pollutant: Toxicity
LOE Subgroup: Toxicity
Matrix: Water
Fraction: Total
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: TOXICITY TESTING
Data Used to Assess Water Quality: Zero of the 8 samples tested with Pimephales promelas were toxic and violated the narrative toxicity objective.
Data Reference: Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
  Monitoring and Reporting Program, Order Nos. R5-2003-0826, R5-2005-0833, and R5-2008-0005 for Coalition Groups Under Resolution No. R5-2003-0105, Conditional Waiver of Waste Discharge Requirements for Discharges From Irrigated Lands Within the Central Valley Region
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CVRWQCB, 2007)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Statistically significant difference from control using a t-test with 4-day acute-style toxicity tests.
Guideline Reference: Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fifth Edition. U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-821-R-02-012
 
Spatial Representation: Samples were collected from Walthal Slough at Woodward Avenue.
Temporal Representation: Samples were collected from April 2003 to September 2003.
Environmental Conditions:
QAPP Information: Data quality: Excellent. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):
 
 
DECISION ID
93694
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of twelve samples exceed the evaluation guideline 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 twelve samples exceed the evaluation guideline for WARM 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 93694, Trifluralin
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72078
 
Pollutant: Trifluralin
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 12
Number of Exceedances: 0
 
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 Trifluralin.
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 Basin Plan states: "Where valid testing has developed 96-hour LC50 values for aquatic organisms..., the Board will consider one tenth of this value for the most sensitive species tested as the upper limit (daily maximum) for the protection of aquatic life... or [O]ther available information on the pesticide..." The evaluation guideline for Trifluralin, 1.58 ug/L, is a maximum acceptable toxicicant concentration (MATC) calculated for Oncorhyncus mykiss (Rainbow trout). USEPA Office of Pesticide Programs Ecotoxicity database)
Guideline Reference: OPP Pesticide Ecotoxicity Database.
 
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.
 
 
DECISION ID
85032
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)(2016)
Revision Status Original
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.

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 samples exceed each of water quality objectives for each of the MUN and WARM water quality objectives.

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 samples exceed each of the water quality objectives for each of the MUN and WARM water quality objectives. 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 85032, 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: 12
Number of Exceedances: 0
 
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: 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 85032, 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: 12
Number of Exceedances: 0
 
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 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: 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.
 
 
DECISION ID
100311
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)(2016)
Revision Status Original
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.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 samples exceed the water quality objective for each of the COMM, 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 samples exceed the water quality objective for each of the COMM, 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: 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 100311, 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: 12
Number of Exceedances: 0
 
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 Endosulfan I.
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: 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 100311, 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: 12
Number of Exceedances: 0
 
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 Endosulfan I.
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: 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 100311, 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: 12
Number of Exceedances: 0
 
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 Endosulfan I.
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: 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.
 
 
DECISION ID
89876
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
Pollutant: alpha.-BHC (Benzenehexachloride or alpha-HCH)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 are available in the administrative record to assess this pollutant. Zero of the 12 samples exceed the COM, zero of the zero samples exceed the MUN 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 samples exceed the COM, zero of the zero samples exceed the MUN water quality objective, and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 89876, alpha.-BHC (Benzenehexachloride or alpha-HCH)
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72090
 
Pollutant: alpha.-BHC (Benzenehexachloride or alpha-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
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 HCH, alpha.
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, alpha criterion, 0.0039 ug/L, is for the protection of human health from the consumption of water and organisms. (California Toxics Rule, 2002)
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for 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 89876, alpha.-BHC (Benzenehexachloride or alpha-HCH)
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72091
 
Pollutant: alpha.-BHC (Benzenehexachloride or alpha-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 12
Number of Exceedances: 0
 
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 HCH, alpha.
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, alpha criterion for the protection of human health from consumption of organisms only is 0.013 ug/L (California Toxics Rule, 2002).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for 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.
 
 
DECISION ID
89931
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
Pollutant: beta-BHC (Benzenehexachloride or beta-HCH)
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 are available in the administrative record to assess this pollutant. Zero of the 12 samples exceed each of the COM and MUN 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 12 samples exceed each of the COM and MUN water quality objectives 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 89931, beta-BHC (Benzenehexachloride or beta-HCH)
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72119
 
Pollutant: beta-BHC (Benzenehexachloride or beta-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 12
Number of Exceedances: 0
 
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 HCH, beta.
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, beta criterion for the protection of human health from the consumption of water and organisms is 0.014 ug/L (California Toxics Rule, 2002).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for 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 89931, beta-BHC (Benzenehexachloride or beta-HCH)
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72120
 
Pollutant: beta-BHC (Benzenehexachloride or beta-HCH)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 12
Number of Exceedances: 0
 
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 HCH, beta.
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, beta criterion for the protection of human health from consumption of organisms only is 0.046 ug/L (California Toxics Rule, 2002).
Objective/Criterion Reference: Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data for this line of evidence for 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.
 
 
DECISION ID
84439
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)(2016)
Revision Status Original
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.

Three lines of evidence are available in the administrative record to assess this pollutant. Zero of 12 samples exceed the water quality objective for each of the COMM, 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 samples exceed the water quality objective for each of the COMM, 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: 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 84439, 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: 12
Number of Exceedances: 0
 
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 Endosulfan II.
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: 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 84439, 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: 12
Number of Exceedances: 0
 
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 Endosulfan II.
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: 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 84439, 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: 12
Number of Exceedances: 0
 
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 Endosulfan II.
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: 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.
 
 
DECISION ID
72040
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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

Four lines of evidence is available in the administrative record to assess this pollutant. Zero of the one samples exceed the MUN, one of the 8 samples exceed the WARM, zero of one samples exceeded the COLD, zero of the one samples exceed the WATER CONTACT RECREATION 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 the one samples exceed the COLD, zero of the one samples exceed the MUN, one of the eight samples exceed the WARM, zero of the one samples exceed the WATER CONTACT RECREATION Criteria/Objective, and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: 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 72040, pH
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72036
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
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: RWB5 Bacti Source ID FY0809
 
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: 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 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 72040, pH
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72034
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
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: RWB5 Bacti Source ID FY0809
 
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: 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 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 72040, pH
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 23234
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
Aquatic Life Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 1
 
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 72040, pH
Region 5     
Walthall Slough (in Delta Waterways, eastern portion)
 
LOE ID: 72035
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
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: RWB5 Bacti Source ID FY0809
 
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: 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 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