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

# Supporting Information

## Regional Board 5 - Central Valley Region

Water Body Name: | New Melones Reservoir
Water Body ID: | CAL5342101020020430113521
Water Body Type: | Lake & Reservoir

DECISION ID | 12590
Pollutant: | Mercury
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Sources: | Resource Extraction
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two 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. Fourteen of 46 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 12590

LOE ID: | 22563
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Total
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 44
Number of Exceedances: | 12
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | Fish were sampled for tissue analysis at multiple locations throughout New Melones Reservoir. A total of 12 out of 44 samples exceeded the USEPA fish tissue criterion for human health. The average wet weight mercury concentration in fish tissue was 0.23 ppm for all 44 samples collected. The number of fish collected per sample, the measured mercury concentrations in fish tissue, and the number of exceedances are, by species: Bluegill- 1 sample, 0.18 ppm, no exceedances; Channel Catfish- 15 samples, 0.05-0.28 ppm (average 0.13 ppm), no exceedances; Kokanee Salmon- 11 samples, 0.08-0.14 ppm (average 0.11 ppm), no exceedances; Largemouth Bass- 10 samples, 0.27-0.94 ppm (average 0.48 ppm), 8 exceedances; Spotted Bass- 5 samples, 0.24-0.53 ppm (average 0.4 ppm), 4 exceedances; White Catfish- 2 samples, 0.03 and 0.05 ppm, no exceedances. All 44 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: | United States Bureau of Reclamation Mercury Fish Study for Folsom and New Melones Reservoirs, 2004-2006. United States Bureau of Reclamation, Mid-Pacific Region, Environmental Monitoring Branch. Unpublished Data
Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. 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 multiple locations throughout New Melones Reservoir. Site locations were not provided with the submitted data.
Temporal Representation: | Fish samples were collected during one sampling event between 8/10/2004 and 8/11/2004.
Environmental Conditions: | Significant gold and mercury mining activity occurred during the Gold Rush era within the New Melones Reservoir watershed and the lands inundated by New Melones Reservoir (USGS, 2005).
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 QAPP for the Survey of Mercury Content in Fish from Folsom Lake and New Melones Reservoir (USBR, 2004).
QAPP Information Reference(s):
LOE ID: | 22564
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: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | Fish were sampled for tissue analysis at one location from New Melones Reservoir. A total of 2 out of 2 samples exceeded the USEPA fish tissue criterion for human health. The average wet weight mercury concentration in fish tissue was 0.39 ppm for the two samples collected. The number of fish collected per sample, the measured mercury concentrations in fish tissue, and the number of exceedances are, by species: Carp- one 5-fish composite sample, 0.42 ppm, 1 exceedance; Largemouth Bass- one 7-fish composite sample, 0.36 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: | Samples were collected at one location from the Angel Creek Arm of New Melones Reservoir.
Temporal Representation: | Fish samples were collected during one sampling event on 9/1/1987.
Environmental Conditions: | Significant gold and mercury mining activity occurred during the Gold Rush era within the New Melones Reservoir watershed and the lands inundated by New Melones Reservoir (USGS, 2005).
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 1987 (Rasmussen and Starrett, 1989).
QAPP Information Reference(s):