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

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name: Solano, Lake
Water Body ID: CAL5112000020020501144846
Water Body Type: Lake & Reservoir
 
DECISION ID
131284
Region 5     
Solano, Lake
 
Pollutant: Mercury
Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not Delist from 303(d) list (TMDL required list)(2018)
Revision Status Revised
Sources: A Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for removal from the CWA section 303(d) List under section 4.5 and 4.11 of the Listing Policy. Under section 4.5 a single line of evidence is necessary to assess listing status. Under section 4.11 when all other delisting factors do not result in the delisting of a water segment but information indicates attainment of standards, a water segment shall be evaluated to determine whether the weight of evidence demonstrates that water quality standard is attained. If the weight of evidence indicates attainment, the water segment shall be removed from the CWA section 303(d) List.

4 lines of evidence are available in the administrative record to assess the pollutant.

LOEs 22594 and 95607 are replaced with LOE 227375. LOE 227375 is a reassessment of the same data following the statewide mercury objectives adopted in 2017.

WILD beneficial use (sport fish objective):
LOE 227368: 1 of 1 samples exceed the mercury objective and consist of 1 trophic level 3 fish.
LOE 227376: 1 of 1 samples exceed the mercury objective and consist of 4 trophic level 3 fish.

COMM beneficial use (sport fish objective):
LOE 227367: 1 of 1 samples exceed the mercury objective and consist of 1 trophic level 3 fish.
LOE 227375: 1 of 1 samples exceed the mercury objective and consist of 4 trophic level 3 fish.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Tissue samples were compared with the sport fish objective and 2 of 2 samples exceed for WILD beneficial use and 2 of 2 samples exceed for the COMM beneficial use. The samples consist of trophic level 3 fish and are from a minimum of 2 annual averages and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. A minimum of 3 annual averages based on composite fish tissue samples must meet the standard to indicate attainment of the standard.
4. 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: This decision was made by SWRCB staff.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 131284, Mercury
Region 5     
Solano, Lake
 
LOE ID: 227376
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Wildlife Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Lower Putah Creek 1997-1998 data for Solano, Lake to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Mercury. This LOE contains data only for trophic level 3 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 4 fish were aggregated into 1 annual averages, which consisted of 2 fish species (3 composite(s) of Sacramento Sucker each composed of 1 fish per composite, 1 composite(s) of Hitch each composed of 1 fish per composite). Of these annual averages, 1 average(s), (Year(s): 1998) exceeded the objective.
Data Reference: Lower Putah Creek 1997-1998 Mercury Biological Distribution Study. Dept. of Environmental Science and Policy, University of California, Davis. February 1999
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Statewide Sport Fish Water Quality Objective for the protection of Wildlife Habitat comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. If trophic level 3 fish are used in the assessment then the Prey Fish Water Quality Objective must also be used to determine that the Sport Fish Objective is being met. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027.
Guideline Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Spatial Representation: Data was collected from 1 station(s) with the station code(s): Lake Solano Study Location 2.
Temporal Representation: Data for this line of evidence were collected between 1998-01-01 and 1998-01-01. When composited fish were collected over multiple days, the first day of fish collection was used as the sample date in the LOE, both for LOE writing, and for averaging period purposes.
Environmental Conditions:
QAPP Information: Data quality: Excellent. Quality Control for the fish sampling, tissue preparation, mercury analysis, and assessment of data precision and accuracy portions of this study was conducted as described in the study report (Slotton et al., 1999).
QAPP Information Reference(s): This is a placeholder for previously assessed data that does not have quality assurance information but would require it under newly developed policies. These LOEs were previously assessed and approved at the Regional, State and Federal level in past cycles. The LOEs needed to be moved and/or reassessed but required this reference code for movement within the decision making database.
 
Line of Evidence (LOE) for Decision ID 131284, Mercury
Region 5     
Solano, Lake
 
LOE ID: 227368
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Wildlife Habitat
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Lower Putah Creek 1997-1998 data for Solano, Lake to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Mercury. This LOE contains data only for trophic level 3 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 1 fish were aggregated into 1 annual averages, which consisted of 1 fish species (1 composite(s) of Sacramento Sucker each composed of 1 fish per composite). Of these annual averages, 1 average(s), (Year(s): 1998) exceeded the objective.
Data Reference: Lower Putah Creek 1997-1998 Mercury Biological Distribution Study. Dept. of Environmental Science and Policy, University of California, Davis. February 1999
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Statewide Sport Fish Water Quality Objective for the protection of Wildlife Habitat comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. If trophic level 3 fish are used in the assessment then the Prey Fish Water Quality Objective must also be used to determine that the Sport Fish Objective is being met. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027.
Guideline Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Spatial Representation: Data was collected from 1 station(s) with the station code(s): Lake Solano Study Location .
Temporal Representation: Data for this line of evidence were collected between 1998-01-01 and 1998-01-01. When composited fish were collected over multiple days, the first day of fish collection was used as the sample date in the LOE, both for LOE writing, and for averaging period purposes.
Environmental Conditions:
QAPP Information: Data quality: Excellent. Quality Control for the fish sampling, tissue preparation, mercury analysis, and assessment of data precision and accuracy portions of this study was conducted as described in the study report (Slotton et al., 1999).
QAPP Information Reference(s): This is a placeholder for previously assessed data that does not have quality assurance information but would require it under newly developed policies. These LOEs were previously assessed and approved at the Regional, State and Federal level in past cycles. The LOEs needed to be moved and/or reassessed but required this reference code for movement within the decision making database.
 
Line of Evidence (LOE) for Decision ID 131284, Mercury
Region 5     
Solano, Lake
 
LOE ID: 227375
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Lower Putah Creek 1997-1998 data for Solano, Lake to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Mercury. This LOE contains data only for trophic level 3 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 4 fish were aggregated into 1 annual averages, which consisted of 2 fish species (3 composite(s) of Sacramento Sucker each composed of 1 fish per composite, 1 composite(s) of Hitch each composed of 1 fish per composite). Of these annual averages, 1 average(s), (Year(s): 1998) exceeded the objective.
Data Reference: Lower Putah Creek 1997-1998 Mercury Biological Distribution Study. Dept. of Environmental Science and Policy, University of California, Davis. February 1999
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Statewide Sport Fish Water Quality Objective for the protection of the Commercial and Sport Fishing beneficial comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027.
Guideline Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Spatial Representation: Data was collected from 1 station(s) with the station code(s): Lake Solano Study Location 2.
Temporal Representation: Data for this line of evidence were collected between 1998-01-01 and 1998-01-01. When composited fish were collected over multiple days, the first day of fish collection was used as the sample date in the LOE, both for LOE writing, and for averaging period purposes.
Environmental Conditions:
QAPP Information: Data quality: Excellent. Quality Control for the fish sampling, tissue preparation, mercury analysis, and assessment of data precision and accuracy portions of this study was conducted as described in the study report (Slotton et al., 1999).
QAPP Information Reference(s): This is a placeholder for previously assessed data that does not have quality assurance information but would require it under newly developed policies. These LOEs were previously assessed and approved at the Regional, State and Federal level in past cycles. The LOEs needed to be moved and/or reassessed but required this reference code for movement within the decision making database.
 
Line of Evidence (LOE) for Decision ID 131284, Mercury
Region 5     
Solano, Lake
 
LOE ID: 227367
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed Lower Putah Creek 1997-1998 data for Solano, Lake to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the water quality threshold for Mercury. This LOE contains data only for trophic level 3 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 1 fish were aggregated into 1 annual averages, which consisted of 1 fish species (1 composite(s) of Sacramento Sucker each composed of 1 fish per composite). Of these annual averages, 1 average(s), (Year(s): 1998) exceeded the objective.
Data Reference: Lower Putah Creek 1997-1998 Mercury Biological Distribution Study. Dept. of Environmental Science and Policy, University of California, Davis. February 1999
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: The Statewide Sport Fish Water Quality Objective for the protection of the Commercial and Sport Fishing beneficial comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027.
Guideline Reference: Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy
 
Spatial Representation: Data was collected from 1 station(s) with the station code(s): Lake Solano Study Location .
Temporal Representation: Data for this line of evidence were collected between 1998-01-01 and 1998-01-01. When composited fish were collected over multiple days, the first day of fish collection was used as the sample date in the LOE, both for LOE writing, and for averaging period purposes.
Environmental Conditions:
QAPP Information: Data quality: Excellent. Quality Control for the fish sampling, tissue preparation, mercury analysis, and assessment of data precision and accuracy portions of this study was conducted as described in the study report (Slotton et al., 1999).
QAPP Information Reference(s): This is a placeholder for previously assessed data that does not have quality assurance information but would require it under newly developed policies. These LOEs were previously assessed and approved at the Regional, State and Federal level in past cycles. The LOEs needed to be moved and/or reassessed but required this reference code for movement within the decision making database.