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

# Supporting Information

## Regional Board 5 - Central Valley Region

Water Body Name: | Sacramento Slough
Water Body ID: | CAR5192200019980814113208
Water Body Type: | River & Stream

DECISION ID | 15244
Pollutant: | Carbaryl
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
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. Three lines of evidence are available in the administrative record to assess this pollutant. Zero water samples exceed the narrative toxicity 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 89 calculated 4-day average carbaryl concentrations exceeded the Evaluation Guideline for carbaryl of 2.53 ug/L (based on the California Department of Fish and Game Hazard Assessment freshwater aquatic life protection carbaryl 4-day average criterion) and, therefore, zero samples exceeded the narrative toxicity objective, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Zero of 99 1-hour average carbaryl concentrations exceeded the Evaluation Guideline for carbaryl of 2.53 ug/L (based on the California Department of Fish and Game Hazard Assessment freshwater aquatic life protection carbaryl 1-hour average criterion) and, therefore, zero samples exceeded the narrative toxicity objective, and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 5. 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 not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15244

LOE ID: | 26235
Pollutant: | Carbaryl
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 33
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Thirty-three water samples were collected from Sacramento Slough between January 2001 and September 2004 by the USGS, and representing 33 four-day average concentrations and 33 one-hour average concentrations. Zero of 33 four-day average concentrations exceeded the four day maximum concentration guideline of 2.53 ug/L. Zero of 33 one-hour average concentrations exceeded the maximum 1-hour concentration of 2.53 ug/L.
Data Reference: | National Water Quality Assessment database, Sacramento Study Unit data
| Sacramento River Watershed Program Annual Reports for 1999-2000, 2000-2001, 2001-2002, 2002-2003, and 2003-2004; and BDAT data 1998-2003
| Quality Assurance Project Plans prepared for Sacramento River Watershed Program
| SRWP Year 6 (2004) toxicity and water chemistry data files
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: | 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 carbaryl criteria for freshwater aquatic life protection: 2.53 ug/L for both 4-day average and 1-hour average concentrations (Siepmann and Jones, 1998).
Guideline Reference: | Hazard Assessment of the Insecticide Carbaryl to Aquatic Organisms in the Sacramento-San Joaquin River System. State of California Department of Fish and Game
Spatial Representation: | Water samples were collected from Sacramento Slough near Knights Landing.
Temporal Representation: | Water samples were collected from Sacramento Slough monthly (or every 2 or three months, intermittently) between 18 January 2001 and 27 September 2004.
Environmental Conditions: |
QAPP Information: | Data Quality: Good.
QAPP Information Reference(s): | National field manual for the collection of water quality data. Reston, VA. U.S. Geological Survey. Office of Water Quality
| Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
LOE ID: | 26234
Pollutant: | Carbaryl
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 22
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Twenty-two water samples were collected from Sacramento Slough in January and February 2004 and in February 2005, under the Pesticide TMDL program, and representing 12 four-day average concentrations and 22 one-hour average concentrations. Zero of 12 calculated 4-day average concentrations exceeded the 4-day maximum concentration guideline of 2.53 ug/L. Zero of 22 available 1-hour average concentrations exceeded the 1-hour maximum concentration guideline of 2.53 ug/L.
Data Reference: | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
| Sacramento River Watershed Program Annual Reports for 1999-2000, 2000-2001, 2001-2002, 2002-2003, and 2003-2004; and BDAT data 1998-2003
| Quality Assurance Project Plans prepared for Sacramento River Watershed Program
| SRWP Year 6 (2004) toxicity and water chemistry data files
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: | 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 carbaryl criteria for freshwater aquatic life protection: 2.53 ug/L for both 4-day average and 1-hour average concentrations (Siepmann and Jones, 1998).
Guideline Reference: | Hazard Assessment of the Insecticide Carbaryl to Aquatic Organisms in the Sacramento-San Joaquin River System. State of California Department of Fish and Game
Spatial Representation: | Water samples were collected from Sacramento Slough.
Temporal Representation: | Water samples were collected from Sacramento Slough daily between 28 January 2004 and 1 February 2004; on 4 February 2004; on 16, 17, 19, 20, and 21 February 2004; and daily between 16 and 26 February 2005.
Environmental Conditions: |
QAPP Information: | Data Quality: Good.
QAPP Information Reference(s): | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
LOE ID: | 26236
Pollutant: | Carbaryl
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 44
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Forty-four water samples were collected from Sacramento Slough between June 1999 and August 2007 by the Sacramento River Watershed Program. The 44 water samples represent 43 four-day average concentrations and 44 one-hour average concentrations. Zero of the 43 four-day average concentrations exceeded the four day maximum concentration guideline of 2.53 ug/L. Zero of the 44 one-hour average concentrations exceeded the maximum 1-hour concentration of 2.53 ug/L.
Data Reference: | National Water Quality Assessment database, Sacramento Study Unit data
| Final Proposition 50 Grant Monitoring Report, 2005 - 2007. Includes Quality Assurance Project Plan (QAPP) Revision 1.2.0, Appendix A, March 2006
| Sacramento River Watershed Program Annual Reports for 1999-2000, 2000-2001, 2001-2002, 2002-2003, and 2003-2004; and BDAT data 1998-2003
| SRWP Year 6 (2004) toxicity and water chemistry data files
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: | 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 carbaryl criteria for freshwater aquatic life protection: 2.53 ug/L for both 4-day average and 1-hour average concentrations (Siepmann and Jones, 1998).
Guideline Reference: | Hazard Assessment of the Insecticide Carbaryl to Aquatic Organisms in the Sacramento-San Joaquin River System. State of California Department of Fish and Game
Spatial Representation: | Water samples were collected from Sacramento Slough near Knights Landing.
Temporal Representation: | Water samples were collected from Sacramento Slough monthly (or, occasionally, twice per month, every two months, or every 3 months) between 22 June 1999 and 16 June 2002; on 26 October 2002, 21 November 2002, and monthly between 3 March 2003 and 24 June 2003; on 20 April 2006, 6 and 25 July 2006, 24 August 2006, 15 and 29 March 2007, 26 April 2007, 16 May 2007, 7 and 27 June 2007, 25 July 2007, and 8 August 2007.
Environmental Conditions: |
QAPP Information: | Data Quality: Good.
QAPP Information Reference(s): | Final Proposition 50 Grant Monitoring Report, 2005 - 2007. Includes Quality Assurance Project Plan (QAPP) Revision 1.2.0, Appendix A, March 2006
| Sacramento River Watershed Program Annual Reports for 1999-2000, 2000-2001, 2001-2002, 2002-2003, and 2003-2004; and BDAT data 1998-2003
| Quality Assurance Project Plans prepared for Sacramento River Watershed Program

DECISION ID | 6776
Pollutant: | Diazinon
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Delist from 303(d) list (TMDL required list)(2006)
Revision Status | Revised
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. Three lines of evidence are available in the administrative record to assess this pollutant. One 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. One of 39 available 4-day average concentrations exceeded the 4-day average maximum concentration criterion and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. In addition, none of 54 available 1-hour average concentrations exceeded the 1-day average concentration criterion 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.
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 placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 6776

LOE ID: | 2657
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 109
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | None of the 109 samples exceeded the criteria for diazinon (Central Valley RWQCB, 2006).
Data Reference: | Placeholder reference 2006 303(d)
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses. 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.
Objective/Criterion Reference: | Placeholder reference 2006 303(d)
Evaluation Guideline: | CDFG Hazard Assessment Criteria 0.16 ug/L 1-hour average, 0.10 ug/L 4-day average (chronic) (Siepman & Finlayson, 2000; Finlayson, 2004).
Guideline Reference: | Placeholder reference 2006 303(d)
Spatial Representation: | Samples were taken near Knights Landing, at Hwy 113, near Verona, at Karnak, and at sites identified as "Sac Slough".
Temporal Representation: | Samples were collected from 2000 thru 2005.
Environmental Conditions: |
QAPP Information: | QA Info Missing
QAPP Information Reference(s):
LOE ID: | 22867
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Ten water samples were collected from Sacramento Slough in January and February 2004, representing 3 4-day average concentrations and 10 1-hour average concentrations.0 of 3 four-day average concentrations exceeded the four day maximum concentration guideline of 0.100 ug/L.0 of 10 one-hour average concentrations exceeded the maximum 1-hour concentration of 0.160 ug/L.
Data Reference: | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007). All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
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 Criteria - 0.160 ug/L 1-hour average and 0.100 ug/L 4-day average concentration (Siepmann and Finlayson, 2000 and Finlayson, 2004).
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: | Sacramento Slough near Karnak. Samples were collected by boat.
Temporal Representation: | Samples were collected daily from 1/28/2004 through 2/4/2004 (not on 2/3/2004), and daily from 2/16/2004 through 2/17/2004 (not on 2/18/2004 because water was flowing the wrong direction because of high water in the Sacramento River). Because of the high water in the Sacramento River, samples were collected in Reclamation Slough on 2/21/2004. Samples collected on 2/20/2004 were not used in the count because the sample location was not clear (Sacramento Slough or Reclamation Slough?). These samples were collected during two storm events.Sacramento Slough backed up because of high water in the Sacramento River. Samples were collected
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: | 22869
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 33
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Thirty-three water samples were collected from January 2001 - September 2004, representing 33 4-day average concentrations and 33 1-hour average concentrations.1 of 33 four-day average concentrations exceeded the four day maximum concentration guideline of 0.100 ug/L.0 of 33 one-hour average concentrations exceeded the maximum 1-hour concentration of 0.160 ug/L.
Data Reference: | National Water Quality Assessment database, Sacramento Study Unit data
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007). All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
Objective/Criterion Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game
| 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 Criteria - 0.160 ug/L 1-hour average and 0.100 ug/L 4-day average concentration (Siepmann and Finlayson, 2000 and Finlayson, 2004).
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: | Sacramento Slough near Knights Landing, California.
Temporal Representation: | Samples were collected monthly from January - September 2001, January - November 2002 (excluding August and October), January - September 2003 (excluding August), and January - September 2004 (excluding February and August).
Environmental Conditions: |
QAPP Information: | Data quality: Good. In accordance with section 6.1.4 of the Listing Policy, data from major monitoring programs in California and Published USGS reports are considered of adequate quality.
QAPP Information Reference(s):
LOE ID: | 22868
Pollutant: | Diazinon
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Ten water samples were collected from Sacramento Slough in February 2005, representing 3 4-day average concentrations and 11 1-hour average concentrations.0 of 3 four-day average concentrations exceeded the four day maximum concentration guideline of 0.100 ug/L.0 of 11 one-hour average concentrations exceeded the maximum 1-hour concentration of 0.160 ug/L.
Data Reference: | Zipped file of Central Valley Waterways Pesticide TMDL monitoring data spreadsheets and reports
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007). All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
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 Criteria - 0.160 ug/L 1-hour average and 0.100 ug/L 4-day average concentration (Siepmann and Finlayson, 2000 and Finlayson, 2004).
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: | Sacramento Slough near Karnak. Samples were collected by boat.
Temporal Representation: | Samples were collected daily from 2/16/2005 through 2/26/2005.
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

DECISION ID | 12383
Pollutant: | Malathion
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
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. 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 59 available 4-day average concentrations exceeded criterion continuous concentration and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. In addition, 0 of 59 available 1-hour average concentrations exceeded 1-hour maximum criterion concentration 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.
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 placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 12383

LOE ID: | 22765
Pollutant: | Malathion
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 26
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | 26 water samples were collected from Sacramento Slough between June 1999 and May 2002, representing 26 four-day average concentrations and 26 one-hour average concentrations. 0 of 26 available 4-day average concentrations exceeded the 4-day maximum concentration guideline of 0.1 ug/L. 0 of 26 available 1-hour average concentrations exceeded the maximum 1-hour concentration of 0.43 ug/L.
Data Reference:
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007).All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
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 Criteria - 0.015 ug/L 4-day average and 0.025 ug/L 1-hour average (Siepmann and Finlayson, 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005).
Guideline Reference:
Spatial Representation: | Samples were collected from Sacramento Slough
Temporal Representation: | Samples were collected between June 1999 and May 2002 at variable intervals (e.g. bi-weekly, monthly).
Environmental Conditions: |
QAPP Information: | Data quality: Excellent. Monitoring was conducted in accordance with the Quality Assurance Project Plan for Monitoring prepared for the Sacramento River Watershed Program (SRWP 1999a, 1999b, 2000b, 2001b, 2002b, 2003b, 2006).
QAPP Information Reference(s):
LOE ID: | 22764
Pollutant: | Malathion
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 33
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | 33 water samples were collected from Sacramento Slough from January 2001 through September 2004, representing 33 four-day average concentrations and 33 one-hour average concentrations.0 of 33 four-day average concentrations exceeded the four day maximum concentration guideline of 0.1 ug/L.0 of 33 one-hour average concentrations exceeded the maximum 1-hour concentration of 0.43 ug/L.
Data Reference:
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007).All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
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
| Quality Criteria for Water. USEPA Office of Water and Hazardous Materials. Washington, D.C
Evaluation Guideline: | US EPA recommended criterion continuous concentration (CCC) 0.1 ug/L (US EPA, 1976). California Department of Fish and Game Hazard Assessment Criterion is 0.43 ug/L for criterion maximum concentration (CMC) (CDFG, 1998)
Guideline Reference: | Hazard Assessment of the Insecticide Malathion to Aquatic Life in the Sacramento-San Joaquin River System. California Department of Fish and Game. Office of Spill Prevention and Response Administrative Report 98-2
Spatial Representation: | Samples were collected from Sacramento Slough near Knight Landing.
Temporal Representation: | Samples were collected from January 2001 through September 2004 at monthly interval.
Environmental Conditions: |
QAPP Information: | Data quality: Good. In accordance with section 6.1.4 of the Listing Policy, data from major monitoring programs in California and Published USGS reports are considered of adequate quality.
QAPP Information Reference(s):

DECISION ID | 15108
Pollutant: | Propanil (DCPA mono- and di-acid degrad)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
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. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the samples exceed the narrative toxicity 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 40 water samples exceeded the Evaluation Guideline for propanil (none exceeded the narrative toxicity objective), 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.
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 placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15108

LOE ID: | 26203
Pollutant: | Propanil (DCPA mono- and di-acid degrad)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 33
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Thirty-three water samples were collected from Sacramento Slough by the USGS between January 2001 and September 2004. None of the 33 water samples had a propanil concentration that exceeded the Evaluation Guideline value of 16 ug/L.
Data Reference: | Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: | 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: | Where valid testing has developed 96 hour LC50 values for aquatic organisms (the concentration that kills one half of the test organisms in 96 hours), 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. Other available technical information on the pesticide (such as Lowest Observed Effect Concentrations and No Observed Effect Levels), the water bodies and the organisms involved will be evaluated to determine if lower concentrations are required to meet the narrative objectives (CVRWQCB, 2007). The 5-day EC50 tested for freshwater diatom (Navicula pelliculosa) is 16 ug/L.
Guideline 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
| Ecotoxicity database. U.S. Environmental Protection Agency, Office of Pesticide Programs
Spatial Representation: | Water samples were collected from Sacramento Slough near Knights Landing.
Temporal Representation: | Water samples were collected monthly between January 2001 and September 2004.
Environmental Conditions: |
QAPP Information: | Data Quality: Good. U.S. Geological Survey, variously dated, National field manual for the collection of water-quality data: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, chaps. A1-A9, available online at http://pubs.water.usgs.gov/twri9A
QAPP Information Reference(s): | National field manual for the collection of water quality data. Reston, VA. U.S. Geological Survey. Office of Water Quality
LOE ID: | 26202
Pollutant: | Propanil (DCPA mono- and di-acid degrad)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 7
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Seven water samples were collected from Sacramento Slough between January and September 2004, as reported in the DPR Surface Water Database. None of the 7 water samples had a propanil concentration that exceeded the Evaluation Guideline value of 16 ug/L.
Data Reference: | Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: | 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: | Where valid testing has developed 96 hour LC50 values for aquatic organisms (the concentration that kills one half of the test organisms in 96 hours), 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. Other available technical information on the pesticide (such as Lowest Observed Effect Concentrations and No Observed Effect Levels), the water bodies and the organisms involved will be evaluated to determine if lower concentrations are required to meet the narrative objectives (CVRWQCB, 2007). The 5-day EC50 tested for freshwater diatom (Navicula pelliculosa) is 16 ug/L.
Guideline 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
| Ecotoxicity database. U.S. Environmental Protection Agency, Office of Pesticide Programs
Spatial Representation: | Water samples were collected from Sacramento Slough near Karnak.
Temporal Representation: | Water samples were collected monthly between January and September 2004.
Environmental Conditions: |
QAPP Information: | Data Quality: Good. Minimum requirements for the Surface Water Database are: Name of the sampling agency or organization Date that each sample was collected Date of each sample analysis County where samples were taken Detailed sampling location information (including latitude and longitude or township/range/section if available), detailed map or description of each sampling site (i.e., address, cross roads, etc.) Name or description of water body sampled Name of the active ingredient analyzed for; concentration detected (with unit of measurement), and limit of quantitation Description of analytical QA/QC plan, or statement that no formal plan exists Additional optional requirements are included on DPRs webpage at http://www.cdpr.ca.gov/docs/emon/surfwtr/caps/req.htm.
QAPP Information Reference(s):

DECISION ID | 12395
Pollutant: | Sediment Toxicity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
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 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 3 samples exceeded the narrative toxicity objective 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.
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 placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 12395

LOE ID: | 25405
Pollutant: | Sediment Toxicity
LOE Subgroup: | Pollutant-Sediment
Matrix: | Sediment
Fraction: | None
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | 0/3 samples were statistically different from the control using Irrigated Lands Regulatory data.
Data Reference: | Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
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.
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: | Statistically significant difference from control using a t-test with 4-day toxicity tests.
Guideline Reference:
Spatial Representation: | Sacramento Slough at Karnak
Temporal Representation: | July 2005-September 2006
Environmental Conditions: |
QAPP Information: | California Regional Water Quality Control Board Central Valley Region Monitoring and Reporting Program Order No. R5-2003-0826 for Coalition Groups Under Resolution No. R5-2003-0105 Conditional Waiver of Waster Discharge Requirements for Discharges from Irrigated Lands.
QAPP Information Reference(s):

DECISION ID | 10290
Pollutant: | Specific Conductivity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for listing under sections 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Data is available from 1 line of evidence for this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification for placing this water segment-pollution combination on the section 303(d) list. The recommendation is based on staff findings that 0 of 25 available concentrations exceeded the water quality objective and this does not exceed the allowable frequency using Table 3.2 of the Listing Policy. Table 3.2 of the listing policy recommends listing if a sample size of 25 has 5 or more samples that exceed the evaluation criteria. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 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 not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10290

LOE ID: | 20838
Pollutant: | Specific Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 25
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | 0 of the 25 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Specific Conductivity.
Data Reference: | SWAMP data entered by SWRCB into BDAT database
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
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 water quality objective used was the California Secondary MCL recommended level of 900 uS/cm. The Basin Plan includes chemical constituent water quality objectives that include (by reference) secondary maximum contaminant levels (MCLs) protective of MUN (CVRWQCB, 2007a).The secondary MCLs for electrical conductivity provide a range of values including a recommended level (900 uS/cm), upper level (1600 uS/cm) and a short-term level (2200 uS/cm). The recommended concentration was used as it is intended to be protective of all drinking water uses.
Guideline Reference: | Compilation of Water Quality Goals
Spatial Representation: | Samples were collected at Sacramento Slough East @ HWY 113. Samples were collected at Sacramento Slough West @ HWY 113.
Temporal Representation: | The samples were collected from Nov 13 2002 to Apr 10 2003
Environmental Conditions: |
QAPP Information: | Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):

DECISION ID | 12387
Pollutant: | Thiobencarb/Bolero
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
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. Two lines of evidence are available in the administrative record to assess this pollutant. One 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. One of 40 available concentrations exceeded the concentration criterion (1 µg/L) 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.
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 placed on the section 303(d) list because applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 12387

LOE ID: | 22855
Pollutant: | Thiobencarb/Bolero
LOE Subgroup: | Pollutant-Water
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: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | 7 water samples were collected from Sacramento Slough from January through September 2004, representing 7 concentrations. 0 of 7 concentrations exceeded Secondary MCL concentration of 1 ug/L.
Data Reference: | Surface Water database (SWDB) for Central Valley waterbodies, 2000-2005
| Correspondence between the Department of Pesticide Regulation and Central Valley Regional Water Quality Control Board regarding water quality data for waterbodies in the Central Valley
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007).All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
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
| California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring. http://www.cdph.ca.gov/certlic/drinkingwater/Pages/Lawbook.aspx
Evaluation Guideline: | Secondary Maximum Contaminant Levels (MCLs) for drinking water standard adopted by the California Department of Public Health (CDPH) is 1 ug/L (CDPH, 2008).
Guideline Reference: | California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring. http://www.cdph.ca.gov/certlic/drinkingwater/Pages/Lawbook.aspx
Spatial Representation: | Samples were collected from Sacramento Slough at Karnak.
Temporal Representation: | Samples were collected at monthly interval from January through September 2004.
Environmental Conditions: |
QAPP Information: | Data quality: Good. Minimum requirements for the CDPR Surface Water Database are: Name of the sampling agency or organization, Date that each sample was collected, Date of each sample analysis, County where samples were taken, Detailed sampling location information (including latitude and longitude or township/range/section if available), detailed map or description of each sampling site (i.e., address, cross roads, etc.), Name or description of water body sampled, Name of the active ingredient analyzed for; concentration detected (with unit of measurement), and limit of quantitation, Description of analytical QA/QC plan, or statement that no formal plan exists. Additional optional requirements are included on DPR's webpage at http://www.cdpr.ca.gov/docs/emon/surfwtr/caps/req.htm
QAPP Information Reference(s): | Standard Operating Procedure for Conducting Surface Water Monitoring for Pesticides
LOE ID: | 22854
Pollutant: | Thiobencarb/Bolero
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 33
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | 33 water samples were collected from Sacramento Slough from January 2001 through September 2004, representing 33 concentrations.1 of 33 concentrations exceeded Secondary MCL (1.0 ug/L)
Data Reference: | National Water Quality Assessment database, Sacramento Study Unit data
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007).All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
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
| California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring. http://www.cdph.ca.gov/certlic/drinkingwater/Pages/Lawbook.aspx
Evaluation Guideline: | Secondary Maximum Contaminate Levels (MCLs) for drinking water standard adopted by the California Department of Public Health (CDPH) is 1 ug/L (CDPH, 2008).
Guideline Reference: | California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring. http://www.cdph.ca.gov/certlic/drinkingwater/Pages/Lawbook.aspx
Spatial Representation: | Sacramento Slough near Knights Landing, California.
Temporal Representation: | Samples were collected monthly from January 2001 through September 2004.
Environmental Conditions: |
QAPP Information: | Data quality: Good. In accordance with section 6.1.4 of the Listing Policy, data from major monitoring programs in California and Published USGS reports are considered of adequate quality.
QAPP Information Reference(s):

DECISION ID | 4682
Pollutant: | Chlorpyrifos
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2006)
Revision Status | Revised
Sources: | Source Unknown
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 samples exceed the narrative toxicity 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 64 available calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion more than once every three years; therefore, in accordance with Section 3.11 of the Listing Policy, this water body should be 303(d)-listed. 4. Zero of 76 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion, and this does not exceed the number of exceedances allowed in Table 3.1 of the Listing Policy. 5. 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 4682

LOE ID: | 22777
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life 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: | Fourteen water samples were collected from Sacramento Slough in January and February 2004, representing five calculated 4-day average chlorpyrifos concentrations and fourteen 1-hour average chlorpyrifos concentrations. Zero of the five available calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos concentration criterion of 0.015 ug/L. Zero of the fourteen available 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: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial use. 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: 0.015 ug/L as a 4-day average chlorpyrifos concentration, and 0.025 ug/L as a 1-hour average chlorpyrifos 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 Sacramento Slough.
Temporal Representation: | Samples were collected daily during three storm events in January and February 2004.
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: | 22778
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
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: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Eleven water samples were collected from Sacramento Slough in February 2005, representing eight calculated 4-day average chlorpyrifos concentrations and eleven 1-hour average chlorpyrifos concentrations. Zero of the eight calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion of 0.015 ug/L. Zero of the eleven 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: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (CVRWQCB, 2007). All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life (CVRWQCB, 2007).
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 Criteria - 0.015 ug/L 4-day average and 0.025 ug/L 1-hour average (Siepmann and Finlayson, 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005).
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 Sacramento Slough.
Temporal Representation: | Samples were collected daily in 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: | 22780
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 18
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Eighteen water samples were collected from Sacramento Slough between January 2000 and May 2002, representing eighteen calculated 4-day average chlorpyrifos concentrations and eighteen 1-hour average chlorpyrifos concentrations. Zero of the eighteen available calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion of 0.015 ug/L. Zero of the eighteen available 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion of 0.025 ug/L.
Data Reference: | Sacramento River watershed program (SRWP) water quality database. Davis, CA
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: | Water quality 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
| 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: 0.015 ug/L as a 4-day average chlorpyrifos concentration, and 0.025 ug/L as a 1-hour average chlorpyrifos 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 Sacramento Slough.
Temporal Representation: | Samples were collected between June 1999 and May 2002 at variable intervals (e.g. bi-weekly, monthly).
Environmental Conditions: |
QAPP Information: | Data quality: Excellent. Monitoring was conducted in accordance with the Quality Assurance Project Plan for Monitoring prepared for the Sacramento River Watershed Program (SRWP 1999a, 1999b, 2000b, 2001b, 2002b, 2003b, 2006).
QAPP Information Reference(s):
LOE ID: | 22779
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Warm Freshwater Habitat
Aquatic Life Use: | Warm Freshwater Habitat
Number of Samples: | 33
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Thirty-three water samples were collected from Sacramento Slough from January 2001 through September 2004, representing thirty-three calculated 4-day average chlorpyrifos concentrations and thirty-three 1-hour average chlorpyrifos concentrations. Zero of the thirty-three calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion of 0.015 ug/L. Two of the thirty-three 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion of 0.025 ug/L.
Data Reference: | National Water Quality Assessment database, Sacramento Study Unit data
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial use. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: | Water quality 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
| 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: 0.015 ug/L as a 4-day average chlorpyrifos concentration, and 0.025 ug/L as a 1-hour average chlorpyrifos 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 Sacramento Slough near Knights Landing.
Temporal Representation: | Samples were collected monthly from January 2001 through September 2004.
Environmental Conditions: |
QAPP Information: | Data quality: Good. In accordance with section 6.1.4 of the Listing Policy, data from major monitoring programs in California and Published USGS reports are considered of adequate quality.
QAPP Information Reference(s):
LOE ID: | 2656
Pollutant: | Chlorpyrifos
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 17
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Seven sites were monitored in the Sacramento River Basin (samples here were recorded from Sacramento Slough). Sampling frequency for each storm event was one sample/day was taken for 7 days. Isokinetic, depth integrated water samples were collected at 6-10 equally spaced points across the channel width with a USGS D-77 sampler using the equal-width-increment method (EWI). Samples were collected from a boat at Sacramento Slough. Seventeen samples were taken; none exceeded the CDFG criteria. (USGS, 2005, LWA, 2002b).
Data Reference: | Placeholder reference 2006 303(d)
Water Quality Objective/Criterion: | Pesticide concentrations shall not exceed those allowable by applicable antidegradation policies (see State Water Resources Control Board Resolution No. 68-16 and 40 CFR section 131.12). No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses. 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. Pesticide concentrations shall not exceed the lowest levels technically and economically achievable. Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of pesticides in excess of the Maximum Contaminant Levels set forth in California Code of Regulations, Title 22, Division 4, Chapter 15.
Objective/Criterion Reference: | Placeholder reference 2006 303(d)
Evaluation Guideline: | CDFG Hazard Assessment Criteria - 14 ng/L 4-day average and 25 ng/L 1-hour average.
Guideline Reference: | Placeholder reference 2006 303(d)
Spatial Representation: | On 2 and 3 February 2004, a single grab sample was collected from the bank. On 4 February and 20 February samples collected were representative of an integrated grab sample. On 18, 21 and 23 February grab samples were collected from the bank at nearby Reclamation Slough - a tributary of Sacramento Slough.
Temporal Representation: | Two storm events were sampled for the 2004 TMDL project in the Sacramento River Basin. The first storm event (Storm 1) was the period 28 January to 6 February 2004. The second storm event (Storm 2) was the period 15-23 February, 2004. For storm 1 sampling was conducted from 28 January to 3 February at most sites, and as late as 6 February at the Tower Bridge at Sacramento site. For storm 2 the sampling period began on 16 February and extended until 22 February.
Environmental Conditions: |
QAPP Information: | Sample quality control was measured through collection of sequential duplicates (n=8), blanks (n=5) and matrix spikes (n=5) (Table 3). The relative percent difference (RPD) between environmental and duplicate sample concentrations of chlorpyrifos ranged from 0-104%. The RPDs between environmental and duplicate sample concentrations of diazinon ranged from 0-40%.
QAPP Information Reference(s):

DECISION ID | 12381
Pollutant: | Oxygen, Dissolved
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Source Unknown
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 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One lines of evidence are available in the administrative record to assess this pollutant. Sixteen 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. Sixteen of 16 available DO concentrations exceed the minimum DO concentration (7 mg/L) in surface water and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
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 12381

LOE ID: | 22769
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 16
Number of Exceedances: | 16
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | 16 samples were taken from Sacramento Slough between September 2004 and August 2006. 16 samples were below the minimum dissolved oxygen concentration (7 mg/L) and 0 sample was below 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
Water Quality Objective/Criterion: | Sacramento/San Joaquin River Basin Plan (CVRWQCB. 2007a) (COLD), Minimum Dissolved Oxygen concentration of 7mg/L(SPWN), Minimum Dissolved Oxygen concentration of 7 mg/L(WARM), Minimum Dissolved Oxygen concentration of 5 mg/L
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: |
Guideline Reference:
Spatial Representation: | Samples were collected from Sacramento Slough near Karnak.
Temporal Representation: | Samples were collected between September 2004 and August 2006 at various intervals (daily, biweekly, or monthly)
Environmental Conditions: |
QAPP Information: | Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):

DECISION ID | 12396
Pollutant: | Unknown Toxicity
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Source Unknown
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. Five lines of evidence are available in the administrative record to assess this pollutant. Fourteen 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. Four of 22 samples exceed the narrative toxicity objective for invertebrates and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. In addition, 10 of 21 samples exceed the narrative toxicity objective for selenastrum 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 12396

LOE ID: | 25406
Pollutant: | Unknown Toxicity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 16
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Samples were collected by the Irrigated Lands Regulatory Program and 0 out of 16 samples tested with ceriodaphnia were statistically different from their control.
Data Reference: | Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
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.
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: | Statistically significant difference from control using a t-test with 4-day toxicity tests.
Guideline Reference:
Spatial Representation: | Sacramento Slough at Karnak
Temporal Representation: | September 2004-October 2006
Environmental Conditions: |
QAPP Information: | California Regional Water Quality Control Board Central Valley Region Monitoring and Reporting Program Order No. R5-2003-0826 for Coalition Groups Under Resolution No. R5-2003-0105 Conditional Waiver of Waster Discharge Requirements for Discharges from Irrigated Lands
QAPP Information Reference(s):
LOE ID: | 25407
Pollutant: | Unknown Toxicity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 6
Number of Exceedances: | 2
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Samples were collected by SWAMPand 2 out of 6 samples tested with ceriodaphnia were statistically different from their control.
Data Reference: | Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
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.
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: | Statistically significant difference from control using a t-test with 4-day toxicity tests.
Guideline Reference:
Spatial Representation: | Sacramento Slough East at Highway 113 and Sacramento Slough West at Highway 113
Temporal Representation: | January-March 2003
Environmental Conditions: |
QAPP Information: | Quality Assurance Management Plan for the State of Californias Surface Water Ambient Monitoring Program 2002
QAPP Information Reference(s):
LOE ID: | 25408
Pollutant: | Unknown Toxicity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 6
Number of Exceedances: | 2
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Samples were collected by SWAMP and 2 out of 6 samples tested with hyelella were statistically different from their control.
Data Reference: | SWAMP data entered by SWRCB into BDAT database
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.
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: | Statistically significant difference from control using a t-test with 4-day toxicity tests.
Guideline Reference:
Spatial Representation: | Sacramento Slough East at Highway 113 and Sacramento Slough West at Highway 113
Temporal Representation: | January-March 2003
Environmental Conditions: |
QAPP Information: | Quality Assurance Management Plan for the State of Californias Surface Water Ambient Monitoring Program 2002
QAPP Information Reference(s):
LOE ID: | 25409
Pollutant: | Unknown Toxicity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 21
Number of Exceedances: | 10
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Valley Regional Water Quality Control Board Irrigated Lands Program 2007 Monitoring Data Review for Zone 1. Ten out of 21 samples tested with selenastrum were statistically different from their control.
Data Reference: | Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
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.
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: | Statistically significant difference from control using a t-test with 4-day toxicity tests.
Guideline Reference:
Spatial Representation: | Sacramento Slough at Karnak
Temporal Representation: | September 2004-October 2006
Environmental Conditions: |
QAPP Information: | California Regional Water Quality Control Board Central Valley Region Monitoring and Reporting Program Order No. R5-2003-0826 for Coalition Groups Under Resolution No. R5-2003-0105 Conditional Waiver of Waster Discharge Requirements for Discharges from Irrigated Lands.
QAPP Information Reference(s):
LOE ID: | 25410
Pollutant: | Unknown Toxicity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 19
Number of Exceedances: | 0
Data and Information Type: | TOXICITY TESTING
Data Used to Assess Water Quality: | Central Valley Regional Water Quality Control Board Irrigated Lands Program 2007 Monitoring Data Review for Zone 1. None of the19 samples tested with pimephales promelas were statistically different from their control.
Data Reference: | Revised Draft of the 2007 Review of the Monitoring Data for the Irrigated Lands Regulatory Conditional Waiver Program
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.
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: | Statistically significant difference from control using a t-test with 4-day toxicity tests.
Guideline Reference:
Spatial Representation: | Sacramento Slough at Karnak
Temporal Representation: | September 2004-October 2006
Environmental Conditions: |
QAPP Information: | California Regional Water Quality Control Board Central Valley Region Monitoring and Reporting Program Order No. R5-2003-0826 for Coalition Groups Under Resolution No. R5-2003-0105 Conditional Waiver of Waster Discharge Requirements for Discharges from Irrigated Lands.
QAPP Information Reference(s):

DECISION ID | 12385
Pollutant: | pH (low)
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Source Unknown
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 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One lines of evidence are available in the administrative record to assess this pollutant. Five 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. Five of 30 available samples had pH values lower than the pH objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
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 12385

LOE ID: | 22856
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Aquatic Life Use: | Cold Freshwater Habitat
Number of Samples: | 30
Number of Exceedances: | 5
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The California Rice Commission collected 30 samples from September 2004 to October 2006. Five of the 30 samples did not meet the evaluation objective and had a pH lower than 6.5.
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: | 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: | 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: | Measurement of pH within the range of 6.5 and 8.5. A low pH value is lower than 6.5
Guideline Reference:
Spatial Representation: | Samples were collected from Sacramento Slough near Karnak.
Temporal Representation: | Sampling occurred from September 2004 to October 2006.
Environmental Conditions: |
QAPP Information: | Data quality: Good. Monitoring was conducted in accordance with Central Valley Water Board Monitoring and Reporting Program (order number R5-2003-0826) requirements (CVRWQCB, 2003)
QAPP Information Reference(s):

DECISION ID | 7161
Pollutant: | Mercury
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: | Source Unknown
Expected TMDL Completion Date: | 2020
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 decision has not changed.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 7161

LOE ID: | 4518
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Not Recorded
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
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):