# Draft 2008 California 303(d)/305(b) Integrated Report

# Supporting Information

## Regional Board 5 - Central Valley Region

Water Body Name: | Calaveras River, Lower (from Stockton Diverting Canal to the San Joaquin River; partly in Delta Waterways, eastern portion)
Water Body ID: | CAR5440000020011128144534
Water Body Type: | River & Stream

DECISION ID | 6031
Pollutant: | Diazinon
Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Revised
Sources: | Agriculture
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess pollutant. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Eight of 32 water samples collected from the lower Calaveras River exceeded the California Fish and Game Hazard Assessment freshwater aquatic life protection, 4-day average criterion of 0.100 µg/L, not to be exceeded more than once every three years, and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
SWRCB Board Decision / Staff Recommendation: | N/A
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 6031

LOE ID: | 21718
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 16
Number of Exceedances: | 6
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Sixteen water samples were collected from the lower Calaveras River between 18 June 2002 and 19 May 2003, representing sixteen calculated 4-day average concentrations and sixteen 1-hour average concentrations. Six of the sixteen 4-day average concentrations exceeded the 4-day average criterion of 0.100 ug/L. Three of the sixteen 1-hour average concentrations exceeded the 1-hour average criterion of 0.160 ug/L.
Data Reference: | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
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.
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | California Fish and Game Hazard Assessment diazinon criteria for freshwater aquatic life protection: 0.160 ug/L (1-hour average) and 0.100 ug/L (4-day average) concentrations, not to be exceeded more than once every three years.
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
| 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: | Water samples were collected from the lower Calaveras River at Ijams Road.
Temporal Representation: | Samples were collected monthly between 18 June and 17 September 2002; on 19 December 2002; on 22 January 2003 and 18 February 2003; and nine times, either weekly or every two weeks, between 3 March and 19 May 2003.
Environmental Conditions: |
QAPP Information: | Data quality: Good. Calanchini, H. 2006. Quality Assurance Project Plan, Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. John Muir Institute of the Environment, U.C. Davis. Davis, CA.
QAPP Information Reference(s): | Quality Assurance Project Plan. Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. Final. SWAMP Project ID 02TM5001 (Revision 0.0). John Muir Institute of the Environment, U.C. Davis. Davis, CA. January 26, 2006
LOE ID: | 21709
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Five water samples were collected daily from the lower Calaveras River between 15 February and 19 February 2005, representing two calculated 4-day average concentrations and five 1-hour average concentrations. Zero of the two calculated 4-day average concentrations exceeded the 4-day average criterion of 0.100 ug/L. Zero of the five 1-hour average concentrations exceeded the 1-hour average criterion of 0.160 ug/L.
Data Reference: | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
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.
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | California Fish and Game Hazard Assessment diazinon criteria for freshwater aquatic life protection: 0.160 ug/L (1-hour average) and 0.100 ug/L (4-day average) concentrations, not to be exceeded more than once every three years.
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
| 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: | Water samples were collected from the lower Calaveras River at Ijams Road.
Temporal Representation: | Samples were collected daily during a storm event, between 15 February and 19 February 2005.
Environmental Conditions: |
QAPP Information: | Data quality: Excellent. Calanchini, H. 2006. Quality Assurance Project Plan, Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. John Muir Institute of the Environment, U.C. Davis. Davis, CA.
QAPP Information Reference(s): | Quality Assurance Project Plan. Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. Final. SWAMP Project ID 02TM5001 (Revision 0.0). John Muir Institute of the Environment, U.C. Davis. Davis, CA. January 26, 2006
LOE ID: | 21759
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Five water samples were collected from the lower Calaveras River, under the Central Valley Water Board's pesticide TMDL program, in March and April 2005, representing five calculated 4-day average concentrations and five 1-hour average concentrations. Zero of the five calculated 4-day average concentrations exceeded the 4-day average criterion of 0.100 ug/L. Zero of the five 1-hour average concentrations exceeded the 1-hour average criterion of 0.160 ug/L.
Data Reference: | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
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.
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | California Fish and Game Hazard Assessment diazinon criteria for freshwater aquatic life protection: 0.160 ug/L (1-hour average) and 0.100 ug/L (4-day average) concentrations, not to be exceeded more than once every three years.
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
| 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: | Water samples were collected from the lower Calaveras River at Ijams Road.
Temporal Representation: | Samples were collected weekly between 2 March and 6 April 2005.
Environmental Conditions: |
QAPP Information: | Data quality: Excellent. Calanchini, H. 2006. Quality Assurance Project Plan, Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. John Muir Institute of the Environment, U.C. Davis. Davis, CA.
QAPP Information Reference(s): | Quality Assurance Project Plan. Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. Final. SWAMP Project ID 02TM5001 (Revision 0.0). John Muir Institute of the Environment, U.C. Davis. Davis, CA. January 26, 2006
LOE ID: | 2801
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference 2006 303(d)
Water Quality Objective/Criterion: |
Objective/Criterion Reference:
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: |
Temporal Representation: |
Environmental Conditions: |
QAPP Information: | QA Info Missing
QAPP Information Reference(s):
LOE ID: | 21708
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 9
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Fifteen water samples were collected from the lower Calaveras River, under the Central Valley Water Board's Pesticide TMDL program, between February and April 2004, representing nine calculated 4-day average concentrations and fifteen 1-hour average concentrations. Two of nine calculated 4-day average concentrations (2 February to 5 February 2005, and 16 February to 19 February 2005) exceeded the 4-day average criterion of 0.100 ug/L. Four of fifteen 1-hour average concentrations (2 February, 3 February, 26 February, and 17 February 2005) exceeded the 1-hour average criterion of 0.160 ug/L.
Data Reference: | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
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.
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | California Fish and Game Hazard Assessment diazinon criteria for freshwater aquatic life protection: 0.160 ug/L (1-hour average) and 0.100 ug/L (4-day average) concentrations, not to be exceeded more than once every three years.
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
| 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: | Water samples were collected from the lower Calaveras River at Ijams Road.
Temporal Representation: | Samples were collected from the lower Calaveras River daily during two storm events (2 February to 6 February 2004 and 16 February to 20 February 2004), weekly in March, and once in early April 2004.
Environmental Conditions: | Water samples were collected during, and after, two storm events in February 2004.
QAPP Information: | Data quality: Good. Calanchini, H. 2006. Quality Assurance Project Plan, Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. John Muir Institute of the Environment, U.C. Davis. Davis, CA.
QAPP Information Reference(s): | Quality Assurance Project Plan. Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. Final. SWAMP Project ID 02TM5001 (Revision 0.0). John Muir Institute of the Environment, U.C. Davis. Davis, CA. January 26, 2006

DECISION ID | 13109
Pollutant: | Chlorpyrifos
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Agriculture
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | 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. Four lines of evidence are available in the administrative record to assess this pollutant. Two 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 in favor of 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. Two of 32 samples exceed the 4-day average maximum concentration criterion and this exceeds the criterion more than once every three years. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 13109

LOE ID: | 21707
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 9
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Fifteen water samples were collected from the lower Calaveras River, under the Central Valley Water Board, Pesticide TMDL program, between February and April 2004. The fifteen water samples represent nine calculated 4-day average concentrations and fifteen 1-hour average concentrations. One of the nine calculated 4-day average concentrations exceeded the 4-day average criterion of 0.015 ug/L. Zero of the fifteen 1-hour average concentrations exceeded the 1-hour average criterion of 0.025 ug/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
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.
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | California Department of Fish and Game Hazard Assessment chlorpyrifos criteria for freshwater aquatic life protection: 0.015 ug/L (4-day average concentration), and 0.025 ug/L (1-hour average concentration), not to be exceeded more than once every three years.
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation: | Water samples were collected from the lower Calaveras River at Ijams Road.
Temporal Representation: | Samples were collected from the lower Calaveras River daily during two storm events (2 February to 6 February 2004 and 16 February to 20 February 2004), weekly in March, and once in early April 2004.
Environmental Conditions: | Water samples were collected during, and after, two storm events in February 2004.
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.
QAPP Information Reference(s):
LOE ID: | 25732
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Five water samples were collected from the lower Calaveras River, under the Central Valley Water Board's pesticide TMDL program, in March and April 2005, representing five calculated 4-day average concentrations and five 1-hour average concentrations. Zero of the five calculated 4-day average concentrations exceeded the 4-day average criterion of 0.100 ug/L. Zero of the five 1-hour average concentrations exceeded the 1-hour average criterion of 0.160 ug/L.
Data Reference: | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
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.
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | California Fish and Game Hazard Assessment chlorpyrifos criteria for freshwater aquatic life protection: 0.025 ug/L (1-hour average) and 0.015 ug/L (4-day average) concentrations, not to be exceeded more than once every three years.
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation: | Water samples were collected from the lower Calaveras River at Ijams Road.
Temporal Representation: | Samples were collected weekly between 2 March and 6 April 2005.
Environmental Conditions: |
QAPP Information: | Data quality: Excellent. Calanchini, H. 2006. Quality Assurance Project Plan, Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. John Muir Institute of the Environment, U.C. Davis. Davis, CA.
QAPP Information Reference(s): | Quality Assurance Project Plan. Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. Final. SWAMP Project ID 02TM5001 (Revision 0.0). John Muir Institute of the Environment, U.C. Davis. Davis, CA. January 26, 2006
LOE ID: | 21706
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Five water samples were collected from the lower Calaveras River, under the Central Valley Regional Board's Pesticide TMDL program, daily between 15 February and 19 February 2005, representing two calculated 4-day average chlorpyrifos concentrations and five 1-hour average chlorpyrifos concentrations. Zero of the two calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion of 0.015 ug/L. Zero of the five 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion of 0.025 ug/L.
Data Reference: | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
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.
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | California Department of Fish and Game Hazard Assessment chlorpyrifos criteria for freshwater aquatic life protection: 0.015 ug/L (4-day average concentration), and 0.025 ug/L (1-hour average concentration), not to be exceeded more than once every three years.
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation: | Water samples were collected from the lower Calaveras River at Ijams Road.
Temporal Representation: | Samples were collected daily during a storm event, between 15 February and 19 February 2005.
Environmental Conditions: |
QAPP Information: | Data quality: Good. Calanchini, H. 2006. Quality Assurance Project Plan, Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. John Muir Institute of the Environment, U.C. Davis. Davis, CA.
QAPP Information Reference(s): | Quality Assurance Project Plan. Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. Final. SWAMP Project ID 02TM5001 (Revision 0.0). John Muir Institute of the Environment, U.C. Davis. Davis, CA. January 26, 2006
LOE ID: | 21704
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 16
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | One of sixteen water samples collected from the lower Calaveras River by the Central Valley Water Board, Pesticide TMDL program between June 2002 and September 2003, exceeded the 4-day average criterion of 0.015 ug/L. Zero of sixteen water samples exceeded the 1-hour average criterion of 0.025 ug/L. The water sample that exceeded the 4-day average criterion was collected on 18 March 2003.
Data Reference: | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
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.
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | California Department of Fish and Game Hazard Assessment chlorpyrifos criteria for the protection of freshwater aquatic life: 0.015 ug/L (4-day average concentration), and 0.025 ug/L (1-hour average concentration), not to be exceeded more than once every three years.
Guideline Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
Spatial Representation: | Samples were collected from the lower Calaveras River at Ijams Road.
Temporal Representation: | Seven water samples were collected approximately monthly from 18 June 2002 to18 February 2003, and 9 water samples were collected approximately weekly from 3 March 2003 to 19 May 2003.
Environmental Conditions: |
QAPP Information: | Data quality: Good. Calanchini, H. 2006. Quality Assurance Project Plan, Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. John Muir Institute of the Environment, U.C. Davis. Davis, CA.
QAPP Information Reference(s): | Quality Assurance Project Plan. Sacramento and San Joaquin River Basins and Sacramento-San Joaquin Delta TMDL Monitoring for Organophosphorus Pesticides and Other Pesticides Identified as Posing a High Risk to Surface Waters. Final. SWAMP Project ID 02TM5001 (Revision 0.0). John Muir Institute of the Environment, U.C. Davis. Davis, CA. January 26, 2006

DECISION ID | 9828
Pollutant: | Mercury
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Resource Extraction
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | 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. Eleven 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 in favor of 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. Nine of 12 water samples exceed the CTR value for total recoverable mercury of 50 ng/L, and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 9828

LOE ID: | 26128
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 12
Number of Exceedances: | 9
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | A total of 15 water samples were collected at one location from the lower Calaveras River representing twelve 30-day average samples. Nine out of the twelve 30-day average samples exceeded the USEPA (CTR) mercury-based numeric criterion for human health. The total recoverable mercury concentrations in water ranged from 2.5 ng/l to 2200 ng/l with an average of 760 ng/l for the twelve 30-day average samples.
Data Reference: | City of Stockton NPDES Municipal Stormwater Program Report of Waste Discharge
Water Quality Objective/Criterion: | The USEPA California Toxics Rule Criteria (CTR) Inland Surface Waters for the protection of human health for the consumption of both water and fish that live in the water is 50 ng/L (30-day average) for total recoverable mercury.
Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected from one location on the lower Calaveras River at North El Dorado Street.
Temporal Representation: | Water samples were collected during fifteen sampling events from 4/12/2003 to 6/5/2006.
Environmental Conditions: | Samples represented a range of flow conditions including wet and dry seasons.
QAPP Information: | Analysis done by labs with approved QAQC programs, in accordance with stormwater permit requirements.
QAPP Information Reference(s):

DECISION ID | 6632
Pollutant: | Pathogens
Final Listing Decision: | List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Revised
Sources: | Urban Runoff/Storm Sewers
TMDL Name: | Stockton Area Sloughs and Rivers - Pathogens
TMDL Project Code: | 721
Date TMDL Approved by USEPA: | 05/13/2008
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | There is sufficient justification to place this pollutant the Being Addressed portion of the 303(d) list because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard.. The Stockton Urban Waterbodies Pathogen TMDL has been approved by the Central Valley Water Board in 2008 and approved by USEPA on 13 may 2008.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the Being Addressed portion of the section 303(d) list because a TMDL has been completed and approved by USEPA and is expected to result in attainment of the standard.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 6632

LOE ID: | 21077
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 74
Number of Exceedances: | 20
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | Total Maximum Daily Load Report for Pathogens in: Five-Mile Slough, Lower Calaveras River, Mormon Slough, Mosher Slough, Smith Canal and Walker Slough, Final Staff Report, Appendix A, Unpublished Water Quality Data. Though included in the datasets for this LOE, the data described in this section does not include Deltakeeper water samples and results assessed in LOE 7003 (ref2932). Twelve of the 57 daily average results for water samples collected by the Deltakeeper exceeded the E. coli Evaluation Guideline value of 235 MPN/100 ml; the dates (and daily average E. coli MPN values) for the exceedances at "Diverting Canal" was: 21 October 2004 (754 MPN); at "UOP" was: 4 February 2004 (6,867 MPN); at "UOP footbridge" were: 21 April 2001 (1,302 MPN); 20 July 2001 (294 MPN); 8 March 2003 (>24,192 MPN); 11 April 2002 (472 MPN); 20 May 2002 (1,872 MPN); 14 April 2003 (3,609 MPN); and 6 February 2004 (419 MPN); at "DR Dock" were: 27 October 2004 (3,464 MPN); and 7 December 2004 (759 MPN); and at an unspecified location on 11 December 2003 (3,783 MPN) . Eight of the 17 daily average results for water samples collected by the CVRWQCB exceeded the E. coli Evaluation Guideline value of 235 MPN/100 ml; the dates (and daily average E. coli MPN values) for the exceedances at "Deltakeeper" were: 17 November 2005 (240 MPN); 19 December 2005 (850 MPN); and 20 December 2005 (700 MPN); at "McAllen Rd" were: 12 October 2005 (260 MPN); 25 October 2005 (600 MPN); and 17 November 2005 (300 MPN); at "UOP" were: 12 October 2005 (550 MPN); and 19 December 2005 (850 MPN).
Data Reference: | Total Maximum Daily Load Report for Pathogens in: Five-Mile Slough, Lower Calaveras River, Mormon Slough, Mosher Slough, Smith Canal and Walker Slough, Final Staff Report, Appendix A, Unpublished Water Quality Data
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. (CRWQCB, 2006)
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | E. coli bacteria levels should not exceed 235 MPN/100 mL in any single sample (USEPA E. coli objective).
Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation: | Though included in the datasets for this LOE, the data described in this section does not include water samples and results assessed in LOE 7003 (ref2932). Water samples were collected by Deltakeeper from the Calaveras River at "Deltakeeper's Dock", "Diverting Canal", "DR Dock", "UOP", "UOP footbridge", and 1 or more unspecified locations (the latter data was not assessed). Water samples were collected by the CVRWQCB from the Calaveras River at "Deltakeeper", McAllen Rd", and "UOP".
Temporal Representation: | Though included in the datasets for this LOE, the data described in this section does not include water samples and results collected by Deltakeeper and assessed as described in LOE 7003 (ref2932). Water samples were collected from the Calaveras River by Deltakeeper at "Diverting Canal" on: 21 October 2004; at "DR Dock" on: 27 March 2003; 8 April 2003; 12, 17,21 and 25 May 2004; 1, 5, 12, 19 and 27 July 2004; 1, 15, 22, and 30 September 2004; 27 October 2004; 7, 13, 20 and 27 December 2004; 5 January 2005; and 26 May 2005; at "UOP" on: 4 February 2004; at "UOP footbridge" on: 12 and 21 April 2001; 30 May 2001; 28 June 2001; 7 and 20 July 2001; 24 and 28 January 2002; 8, 11, 14 and 24 February 2002; 4, 8, 14, 20 and 29 March 2002; 11, 18 and 25 April 2002; 2, 9, 14, 20 and 31 May 2002; 27 March 2003; 14 April 2003; 2, 6 and 9 February 2004; and 26 March 2004; and at unspecified location(s) on: 11 December 2003; 25 April 2000; 2 May 2000; 13 June 2000; and 9 August 2000. Water samples were collected from the Calaveras River by the CVRWQCB at "Deltakeeper" on: 12 and 25 October 2005; 11, 17 and 28 November 2005; and 6, 19 and 20 December 2005; at "McAllen Rd" on: 12 and 25 October 2005; and 17 November 2005; at "UOP" on: 12 and 25 October 2005; 11, 17 and 28 November 2005; and 6, 19 and 20 December 2005.
Environmental Conditions: |
QAPP Information: | Good. Monitoring was conducted by Deltakeeper and by the Central Valley Water Board for the San Joaquin River TMDL for pathogens
QAPP Information Reference(s):
LOE ID: | 7003
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 33
Number of Exceedances: | 11
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | DeltaKeeper submitted bacteria data for water samples collected from two locations on the lower Calaveras River (Jennings, 2001). One sampling location is near the mouth of the river and the other is approximately four miles upstream. A total of 26 samples collected at the upstream location over during 10 months in 2000-2001, and a total of 11 samples collected at the downstream location during seven months in 2000, were analyzed. Geometric means of the bacteria counts have been calculated using the data submitted by DeltaKeeper. The geometric mean for E. coli is 322 MPN per 100 ml for samples collected at the upstream location (exceeding the USEPA criterion of 126 MPN per 100 ml). The geometric mean for E. coli for samples collected at the downstream location is 76 MPN per 100 ml. One (collected on 24 May 2000) of eleven water samples collected from the downstream site exceeded the USEPA single sample criterion of 235 MPN per 100 ml. Twenty-four water samples collected from the upstream site (at UOP footbridge) yielded 22 daily average MPN E. coli concentrations. Ten (collected on 28 August 2000; 11 October 2000; 30 October 2000; 8, 11, and 24 January 2001; 10 and 11 February 2001; and 5 and 26 March 2001 ) of the 22 water samples collected from the upstream site exceeded the USEPA single sample criterion of 235 MPN per 100 ml.
Data Reference: | Letter from Bill Jennings (DeltaKeeper A Project of San Francisco BayKeeper) to Mr. Jerry Bruns and Mr. Joe Karkoski (California Regional Water Quality Control Board, Central Valley Region) dated May 14, 2001, regarding DeltaKeeper comments on section 303(d) list update
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. (CRWQCB, 2006)
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | The California Department of Health Services (CDHS) has adopted regulations for recreational waters and beaches for single samples of total coliform bacteria of 10,000 Most Probable Number (MPN) per 100 milliliters and of 1,000 MPN per 100 ml for 30-day log mean of sample levels (Title 17 California Code of Regulation section 7958). CDHS has also published draft guidelines that include limits for single samples of E. coli of 235 MPN per 100 milliliters (CDHS, July 2000 http://www.dhs.ca.gov/ps/ddwem/beaches/freshwater.htm). USEPA guidelines for bacteria contained in Ambient Water Quality Criteria for Bacteria (USEPA, 1986a) state Based on a statistically sufficient number of samples (generally not less than 5 samples equally spaced over a 30-day period), the geometric mean of the indicated bacterial densities should not exceed one or the other of the following: E. coli 126 MPN per 100 ml; or Enterococci 33 MPN per 100 ml. A methodology for determining exceedances based on single samples is also included in the standards.
Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation: | The original listing info in the Central Valley Water Board's 2002 303(d) list report indicated that the impaired portion of the lower 5 miles of the Calaveras River, within the Stockton urban area, have similar land use patterns and were recommended for listing as impaired due to pathogen contamination. Water samples were collected from two loations - near the mouth of the Calaveras River (Calaveras River at UOP footbridge), and approximately 4 miles upstream (Calaveras River at Deltakeeper Dock).
Temporal Representation: | Twenty-four water samples were collected at the upstream location (at UOP footbridge) on 7, 14, 22, and 28 August 2000; 20 September 2000; 4, 11, 19, and 30 October 2000; 11, 21, and 28 November 2001; 6 December 2000, 8, 11, and 24 January 2001; 10 and 11 February 2001; and 5, 14, 20 and 26 March 2001. Eleven water samples were collected at the downstream location (at Deltakeeper Doc) on 12, 26 and 27 April 2000; 10 and 24 May 2000; 1 and 21 June 2000; 28 July 2000; 18 August 2000; 12 September 2000; and 3 October 2000.
Environmental Conditions: | tidal phase information was reported for most sampling dates
QAPP Information: | Assumed to be good, since the samples were collected by the Deltakeeper organization.
QAPP Information Reference(s):

DECISION ID | 6631
Pollutant: | Organic Enrichment/Low Dissolved Oxygen
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Original
Sources: | Urban Runoff/Storm Sewers
Expected TMDL Completion Date: | 2012
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.
RWQCB Board Decision / Staff Recommendation: | No new data were assessed for 2008. The Regional Board will update this decision when new data and information become available and are assessed.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 6631

LOE ID: | 4291
Pollutant: | Organic Enrichment/Low Dissolved Oxygen
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference pre-2006 303(d)
Water Quality Objective/Criterion: | Unspecified
Objective/Criterion Reference: | Placeholder reference pre-2006 303(d)
Evaluation Guideline: | Unspecified
Guideline Reference: | Placeholder reference pre-2006 303(d)
Spatial Representation: | Unspecified
Temporal Representation: | Unspecified
Environmental Conditions: | Unspecified
QAPP Information: | Unspecified
QAPP Information Reference(s):