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

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name: Stony Gorge Reservoir
Water Body ID: CAL5222200020000209112836
Water Body Type: Lake & Reservoir
 
DECISION ID
11929
 
Pollutant: Mercury
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: 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.

Three lines of evidence are available in the administrative record to assess this pollutant. Eleven of the samples exceed the water quality objective.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Eleven of 62 samples exceed the USEPA fish tissue criterion for human health 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 11929
 
LOE ID: 22417
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 2
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Fish were sampled for tissue analysis at one location from Stony Gorge Reservoir. A total of 1 out of 2 samples exceeded the USEPA fish tissue criterion for human health. The average wet weight mercury concentration in fish tissue was 0.34 ppm for the 2 samples collected. The number of fish collected per sample, the measured mercury concentrations in fish tissue, and the number of exceedances are, by species: Black Crappie- 1 sample, 0.22 ppm, no exceedances; Largemouth Bass- 1 sample, 0.46 ppm, 1 exceedance. Both composite samples were collected from fish with average total lengths greater than 150 mm, which represent fish most commonly caught and consumed by sport fishers and their families.
Data Reference: SWRCB-DWQ. 2002. Toxic Substances Monitoring Program: Freshwater Bioaccumulation Monitoring: TSM Program Data 1978-2000. State Water Resources Control Board, Division of Water Quality
 
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. The 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: The USEPA Fish Tissue Residue Criterion for methylmercury in fish is 0.3 mg/kg (0.3 ppm) for the protection of human health. This is the concentration in fish tissue that should not be exceeded based on a total fish and shellfish consumption-weighted rate of 0.0175 kg fish/day. (USEPA, 2001)
Guideline Reference: Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
 
Spatial Representation: The sample was collected at one location near the center of Stony Gorge Reservoir.
Temporal Representation: Fish samples were collected during one sampling event on 8/7/1985.
Environmental Conditions:
QAPP Information: Data quality: Good.. Quality Control for the fish sampling, tissue preparation, mercury analysis, and QA sample analysis portions of this study was conducted as described in the Toxic Substance Monitoring Report for 1985 (Rasmussen et al., 1987).
QAPP Information Reference(s):

 
LOE ID: 22416
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 4
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Fish were sampled for tissue analysis at one location from Stony Gorge Reservoir. A total of 1 out of 4 samples exceeded the USEPA fish tissue criterion for human health. The average wet weight mercury concentration in fish tissue was 0.27 ppm for the 4 samples collected. The number of fish collected per sample, the measured mercury concentrations in fish tissue, and the number of exceedances are, by species: Channel Catfish- 3 samples, 0.23-0.27 ppm (average 0.25 ppm), no exceedances; Largemouth Bass- 1 sample, 0.34 ppm, 1 exceedance. All 4 samples were collected from fish with total lengths greater than 150 mm, which represent fish most commonly caught and consumed by sport fishers and their families.
Data Reference: Mercury Contamination in Fish from Northern California Lakes and Reservoirs. State of California. The Resources Agency. Department of Water Resources. Northern District. July 2007
 
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. The 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: The USEPA Fish Tissue Residue Criterion for methylmercury in fish is 0.3 mg/kg (0.3 ppm) for the protection of human health. This is the concentration in fish tissue that should not be exceeded based on a total fish and shellfish consumption-weighted rate of 0.0175 kg fish/day. (USEPA, 2001)
Guideline Reference: Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
 
Spatial Representation: Samples were collected at one location from the southern end of Stony Gorge Reservoir.
Temporal Representation: Fish samples were collected during the spring and summer of 2000 and 2001.
Environmental Conditions:
QAPP Information: Data quality: Excellent.. Quality control for sample collection, preparation, handling, and analyses were conducted in accordance with the Surface Water Ambient Monitoring Program Quality Assurance Program Plan (Puckett, 2002) with the following exception: instead of wrapping fish in Teflon sheets before being frozen and transported to the laboratory, the fish were wrapped in aluminum foil (dull side to skin). This wrapping method should not have affected mercury concentrations. Quality control procedures for selection of target fish species and compositing of samples followed the General Protocol for Sport Fish Sampling and Analysis developed by OEHHA (Gassel and Brodberg, 2005). Gassel, M. and R.K. Brodberg. 2005. General Protocol for Sport Fish Sampling and Analysis. California Environmental Protection Agency, Office of Environmental Health Hazard Assessment (OEHHA), Pesticide and Environmental Toxicology Branch. December 2005.
QAPP Information Reference(s):

 
LOE ID: 22415
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 56
Number of Exceedances: 9
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Fish were sampled for tissue analysis at two locations from Stony Gorge Reservoir. A total of 9 out of 56 samples exceeded the USEPA fish tissue criterion for human health. 1) Stony Gorge Reservoir, near the dam: The average wet weight mercury concentration in fish tissue was 0.17 ppm for the 29 samples collected at this location. The number of fish collected per sample, the measured mercury concentrations in fish tissue, and the number of exceedances are, by species: Bluegill- 4 samples, 0.07-0.24 ppm (average 0.13 ppm), no exceedances; Carp- 5 samples, 0.08-0.27 ppm (average 0.2 ppm), no exceedances; Channel Catfish- 12 samples, 0.12-0.3 ppm (average 0.19 ppm), no exceedances; Goldfish- 5 samples, 0.05-0.15 ppm (average 0.11 ppm), no exceedances; Largemouth Bass- 3 samples, 0.19-0.27 ppm (average 0.24 ppm), no exceedances. 2) Stony Gorge Reservoir, South: The average wet weight mercury concentration in fish tissue was 0.25 ppm for the 27 samples collected at this location. The number of fish collected per sample, the measured mercury concentrations in fish tissue, and the number of exceedances are, by species: Bluegill- 5 samples, 0.09-0.14 ppm (average 0.11 ppm), no exceedances; Carp- 12 samples, 0.24-0.51 ppm (average 0.34 ppm), 8 exceedances; Channel Catfish- 1 sample, 0.12 ppm, no exceedances; Goldfish- 5 samples, 0.13-0.27 ppm (average 0.16 ppm), no exceedances; Largemouth Bass- 4 samples, 0.23-0.36 ppm (average 0.28 ppm), 1 exceedance. All 56 samples were collected from fish with total lengths greater than 150 mm, which represent fish most commonly caught and consumed by sport fishers and their families.
Data Reference: Fish Mercury Project, Year 2 Annual Report, Sport Fish Sampling and Analysis. Final Report. October 2007
 
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. The 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: The USEPA Fish Tissue Residue Criterion for methylmercury in fish is 0.3 mg/kg (0.3 ppm) for the protection of human health. This is the concentration in fish tissue that should not be exceeded based on a total fish and shellfish consumption-weighted rate of 0.0175 kg fish/day. (USEPA, 2001)
Guideline Reference: Water Quality Criterion for the Protection of Human Health: Methylmercury. Final. United States Environmental Protection Agency Office of Science and Technology Office of Water. EPA-823-R-01-001. January 2001
 
Spatial Representation: Samples were collected at two locations from Stony Gorge Reservoir: near the Stony Gorge Dam, and at the southern end of the reservoir.
Temporal Representation: Fish samples were collected during one sampling event on 7/26/2006.
Environmental Conditions:
QAPP Information: Data quality: Excellent.. Quality Control for all of the elements described in section 6.1.4 of the Policy was conducted in accordance with the Laboratory QAPP developed by Moss Landing Marine Laboratories (MLML, 2005). This data was also collected and analyzed in accordance with the CALFED Mercury Project QAPP (Puckett and van Buuren, 2000).
QAPP Information Reference(s):