| Water Body Name: | Duck Slough (in Delta Waterways, northern portion) |
| Water Body ID: | CAR5100000020080623183037 |
| Water Body Type: | River & Stream |
DECISION ID |
92262 |
Region 5 |
Duck Slough (in Delta Waterways, northern portion) |
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| Pollutant: | Chlorpyrifos |
| 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 (being addressed by USEPA approved TMDL)(2016) |
| Revision Status | Original |
| Sources: | Agriculture |
| TMDL Name: | Delta Diazinon and Chlorpyrifos Project |
| TMDL Project Code: | 185 |
| Date TMDL Approved by USEPA: | 10/10/2007 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | During the 2014 Integrated Report cycle, this water body and pollutant combination was considered for removal from the 303(d) list under sections 2.2 and 4.11 of the Listing Policy. Under section 4.11, a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. The evidence indicates that chlorpyrifos concentrations are not attaining the applicable water quality standards, but other pollution control requirements, under State authority, are stringent enough to implement applicable water quality standards.
Based on the readily available data and information, the weight of evidence indicates this water segment-pollutant combination is being addressed by an enforceable regulatory program, other than a TMDL, that is reasonably expected to result in attainment of the water quality standards within a reasonable, specified time frame. This conclusion is based on the staff findings that: 1. The data used 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 thirty available calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion, and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Nine of forty-eight available 1-hour average chlorpyrifos concentrations exceeded the 1-hour average chlorpyrifos criterion, and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 5. In 2007, the Board adopted a TMDL through amendments to the Basin Plan for the control of diazinon and chlorpyrifos runoff into the Sacramento-San Joaquin Delta. USEPA approved the TMDL on 10 October 2007. Resolution R5-2006-0061, by which the Board adopted the TMDL, established site specific numeric objectives for diazinon and chlorpyrifos in the Delta Waterways, an implementation program to reduce pesticide runoff and diazinon and chlorpyrifos dischargers into the Delta Waterways, including the loading capacity and allocations requirements of a TMDL, modified Basin Plan Chapter V (Surveillance and Monitoring) to include monitoring requirements to allow the Central Valley Water Board to assess progress in reducing diazinon and chlorpyrifos discharges and preventing toxicity from pesticide runoff and required dischargers of diazinon and chlorpyrifos to develop and implement a plan to reduce diazinon and chlorpyrifos levels in the Delta Waterways. The Resolution also stated ¿Pursuant to CWC Section 13267, the Executive Officer will require dischargers to submit a management plan that describes the actions that the discharger will take to reduce diazinon and chlorpyrifos discharges and meet the applicable allocations by the required compliance date. The management plan may include actions required by State and Federal pesticide regulations. The Executive Officer will require the discharger to document the relationship between the actions to be taken and the expected reductions in diazinon and chlorpyrifos discharges. The Executive Officer will allow individual dischargers or a discharger group or coalition to submit management plans. The management plan must comply with the provisions of any applicable waiver of waste discharge requirements or waste discharge requirements. The Executive Officer may require revisions to the management plan if compliance with applicable allocations is not attained or the management plan is not reasonably likely to attain compliance.¿ 6. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
| Regional Board Decision Recommendation: | After review of the available data and information described in the lines of evidence associated with this decision, the Regional Water Board determined that this water body and pollutant combination is still impaired and that it should be listed as being addressed by another regulatory program that is reasonably expected to result in attainment of the water quality standard within a reasonable, specified time frame because an alternative State regulatory program is in place which can be reasonably expected to result in attainment of the water quality standard within a reasonable, specified time frame. |
| State Board Review of Regional Board Conclusion and Recommendation: | 5. In 2007, the Board adopted a TMDL through amendments to the Basin Plan for the control of diazinon and chlorpyrifos runoff into the Sacramento-San Joaquin Delta. USEPA approved the TMDL on 10 October 2007.
Resolution R5-2006-0061, by which the Board adopted the TMDL, established site specific numeric objectives for diazinon and chlorpyrifos in the Delta Waterways, an implementation program to reduce pesticide runoff and diazinon and chlorpyrifos dischargers into the Delta Waterways, including the loading capacity and allocations requirements of a TMDL, modified Basin Plan Chapter V (Surveillance and Monitoring) to include monitoring requirements to allow the Central Valley Water Board to assess progress in reducing diazinon and chlorpyrifos discharges and preventing toxicity from pesticide runoff and required dischargers of diazinon and chlorpyrifos to develop and implement a plan to reduce diazinon and chlorpyrifos levels in the Delta Waterways. The Resolution also stated ¿Pursuant to CWC Section 13267, the Executive Officer will require dischargers to submit a management plan that describes the actions that the discharger will take to reduce diazinon and chlorpyrifos discharges and meet the applicable allocations by the required compliance date. The management plan may include actions required by State and Federal pesticide regulations. The Executive Officer will require the discharger to document the relationship between the actions to be taken and the expected reductions in diazinon and chlorpyrifos discharges. The Executive Officer will allow individual dischargers or a discharger group or coalition to submit management plans. The management plan must comply with the provisions of any applicable waiver of waste discharge requirements or waste discharge requirements. The Executive Officer may require revisions to the management plan if compliance with applicable allocations is not attained or the management plan is not reasonably likely to attain compliance.¿ 6. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
| State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
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| LOE ID: | 22069 | ||||
| Pollutant: | Chlorpyrifos | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Total | ||||
| Beneficial Use: | Warm Freshwater Habitat | ||||
| Aquatic Life 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 Duck Slough in February 2005, representing two calculated 4-day average chlorpyrifos concentrations and five 1-hour average chlorpyrifos concentrations. Zero of the two 4-day average chlorpyrifos concentrations exceeded the 4-day maximum chlorpyrifos concentration 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 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed | ||||
| 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 Duck Slough at Five Points. | ||||
| Temporal Representation: | Samples were collected daily during one storm event in February 2005. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | 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 | ||||
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| LOE ID: | 22067 | ||||
| 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: | 2 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Twenty-seven water samples were collected from Duck Slough from June 2002 through May 2003, representing eighteen calculated 4-day average chlorpyrifos concentrations and twenty-seven 1-hour average chlorpyrifos concentrations. Two of the eighteen calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion of 0.015 ug/L. Zero of the twenty-seven 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 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed | ||||
| Objective/Criterion Reference: | Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game | ||||
| Evaluation Guideline: | California Department of Fish and Game 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 Duck Slough at Five Points. | ||||
| Temporal Representation: | Samples were collected daily during two storms in January and February 2003, and at variable intervals (biweekly, weekly, and monthly) between June 2002 and May 2003. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | 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 | ||||
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| LOE ID: | 22068 | ||||
| Pollutant: | Chlorpyrifos | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Total | ||||
| Beneficial Use: | Warm Freshwater Habitat | ||||
| Aquatic Life Use: | Warm Freshwater Habitat | ||||
| Number of Samples: | 10 | ||||
| Number of Exceedances: | 7 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Sixteen water samples were collected from Duck Slough from February through April 2004, representing ten calculated 4-day average chlorpyrifos concentrations and sixteen 1-hour average chlorpyrifos concentrations. Seven of the ten calculated 4-day average chlorpyrifos concentrations exceeded the 4-day average chlorpyrifos criterion of 0.015 ug/L. Nine of the sixteen 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 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed | ||||
| 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 a1-hour average chlorpyrifos criterion, 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 Duck Slough at Five Points. | ||||
| Temporal Representation: | Samples were collected daily during two storm events in February 2004 and weekly from March through April 2004. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | 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 | ||||