Draft California 2026 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name: Virginia Lakes (Mono County)
Water Body ID: CAL6304005220100103210430
Water Body Type: Lake & Reservoir
 
DECISION ID
162441
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Atrazine
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 162441, Atrazine
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341146
 
Pollutant: Atrazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Atrazine.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Maximum Contaminant Level for atrazine incorporated by reference in the Water Quality Control Plan, Lahontan Region is 1 ug/L (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
Line of Evidence (LOE) for Decision ID 162441, Atrazine
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341142
 
Pollutant: Atrazine
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Atrazine.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
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, Lahontan Region).
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of < 1 ug/L for a nonvascular plant (acute). The benchmark was derived from a 'less-than' value (for example, <1,500) and may underestimate toxicity.
Guideline Reference: OPP Aquatic Life Benchmarks
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
 
DECISION ID
162442
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Chloride
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 162442, Chloride
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 348042
 
Pollutant: Chloride
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data to determine beneficial use support and results are as follows:
0 of 1 samples exceeded the water quality threshold for Chloride
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Basin Plan objective for Chloride in this water body is 2 (mg/L), (as a Mean).
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: NLA12_CA-R13 (NARS_WQX-NLA12_CA-R13)
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
 
DECISION ID
162443
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Chlorophyll-a
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 162443, Chlorophyll-a
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341216
 
Pollutant: Chlorophyll-a
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorophyll a.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect the water for beneficial uses.
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: North Carolina Administrative code (NCAC), Title 15A ? Environmental and Natural Resources, Subchapter 2B-Surface water and wetland standards, Rule 0211-Fresh surface water quality standards for class C waters (Class C is defined as freshwaters protected for secondary recreation, fishing, aquatic life including propagation and survival, and wildlife).?Section 3(a) of Rule 0211 applies to all fresh surface waters and states that chlorophyll a is not to exceed 40 ug/L.
Guideline Reference: North Carolina standards, criteria, or toxic concentrations. Adopted per title 15A North Carolina Administrative Code subchapter 2B - Surface water and wetland standards
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
 
DECISION ID
74403
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Mercury
Final Listing Decision: Do Not 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)(2016)
Revision Status Revised
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5 a single line of evidence is necessary to assess listing status.

Two lines of evidence which assess fish tissue data for the COMM and WILD beneficial uses are available in the administrative record to assess this pollutant. 0 of 1 composite trophic level three fish tissue samples comprised of ten individual fish exceed the applicable guidelines for both the COMM and WILD beneficial use assessments. There is insufficient information to determine if the beneficial uses are fully supported - a minimum of three composites are needed per beneficial use to fully determine the use support rating.

LOE 133087 replaces the 2012 LOEs 46040 & 47538 which were written using a now superseded objective. These data have been reassessed using the new objectives and the information now resides in LOE 133087. The 2012 LOEs will be removed completely for the next iteration of this decision.

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 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. 0 of 1 fish tissue samples exceed the applicable objectives for the COMM and WILD beneficial use assessments and these sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of three composite samples per beneficial use assessment are needed to determine if a beneficial use is fully supported in accordance with the mercury objectives.
4. Pursuant to SECTION 3.11 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, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 74403, Mercury
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 132922
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Wildlife Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP Sportfish Contamination in Lakes and Resrv data for Virginia Lakes (Mono County) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality standard 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 10 fish were aggregated into 1 annual averages, which consisted of 1 fish species (2 composite(s) of Rainbow Trout each composed of 5 fish per composite).
Data Reference: Statewide Lakes Sportfish Contamination Study 2007 2008
 
SWAMP Data: 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 Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
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): 630PVL031.
Temporal Representation: Data for this line of evidence were collected between 2007-10-18 and 2007-10-18
Environmental Conditions:
QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP L:akes and Reserviors study
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 74403, Mercury
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46040
 
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: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Mercury. The 1 sample for rainbow trout consisted of 2 composites (5 fish per composite) that were not independent and so were averaged. The results of the composites collected on the same day were averaged, per USEPA 2001, resulting in a total of one sample and zero exceedances. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
  Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Lahontan Region: 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.
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The USEPA 304(a) recommended water quality criterion for concentrations of methylmercury in fish tissue of trophic level 4 fish (150 - 500 mm; fillet wet weight) is 0.20 mg/kg. Total mercury is usually analyzed for most fish studies and assumed to be 100 percent methylmercury for the purposes of risk assessment (Klasing & Brodberg 2008).
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: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. Samples were collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 74403, Mercury
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 133087
 
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: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed SWAMP Sportfish Contamination in Lakes and Resrv data for Virginia Lakes (Mono County) to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the water quality standard 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 10 fish were aggregated into 1 annual averages, which consisted of 1 fish species (2 composite(s) of Rainbow Trout each composed of 5 fish per composite). This LOE does not contain data from fish whos average length was outside of the legal size limits as described by the California Department of Fish and Wildlife Fishing Regulations.
Data Reference: Statewide Lakes Sportfish Contamination Study 2007 2008
 
SWAMP Data: 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 Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
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): 630PVL031.
Temporal Representation: Data for this line of evidence were collected between 2007-10-18 and 2007-10-18
Environmental Conditions:
QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP L:akes and Reserviors study
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 74403, Mercury
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 47538
 
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: 2
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Mercury. The two samples for rainbow trout consisted of 2 composites (5 fish per composite). Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
  Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Lahontan Region: 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.
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The USEPA 304(a) recommended water quality criterion for concentrations of methylmercury in fish tissue of trophic level 4 fish (150 - 500 mm; fillet wet weight) is 0.2 mg/kg. Total mercury is usually analyzed for most fish studies and assumed to be 100 percent methylmercury for the purposes of risk assessment (Klasing & Brodberg 2008). The fish consumption rate of 32 g/day is considered more protective of human health since recommendations are now to eat one meal per week of fish to obtain necessary Omega-3 nutrition. The fish consumption rate of 32 g/day is also protective of wildlife, as it protects 6 out of 7 endangered species.
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: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. Samples were collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
170304
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Microcystins
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
 
Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 170304, Microcystins
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341506
 
Pollutant: Microcystins
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Wildlife Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Microcystins, Total.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
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, Lahontan Region).
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: California Office of Environmental Health Hazard Assessment (OEHHA) established 2 ug/L of microcystins as the subchronic water concentration for dog intake/ingestion (Office of Environmental Health Hazard Assessment Public Health Action Level for microcystin and Human Recreational Uses (May 2012)). OEHHA Action Level for subchronic water intake, dog.
Guideline Reference: Toxicological Summary and Suggested Action Levels to Reduce Potential Adverse Health Effects of Six Cyanotoxins
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
Line of Evidence (LOE) for Decision ID 170304, Microcystins
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341505
 
Pollutant: Microcystins
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Microcystins, Total.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
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, Lahontan Region).
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: USEPA 10-day microcystin health advisory for bottle-fed infants and young children of pre-school age is 0.3 ug/L.
Guideline Reference: Drinking Water Health Advisory for the Cyanobacterial Microcystin Toxins
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
Line of Evidence (LOE) for Decision ID 170304, Microcystins
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341509
 
Pollutant: Microcystins
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Microcystins, Total.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
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, Lahontan Region).
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The California Cyanobacteria and Harmful Algal Bloom (CCHAB) Network established 6 ug/L of microcystins as the water concentration protective of swimmers and other contact recreational users including water-skiing/jet-skiing, fishing, boating, sail boarding, and canoeing.
Guideline Reference: Appendix to the CCHAB preliminary changes to the statewide voluntary guidance on cyanoHABs in recreational waters, January 2016. Appendix A. Description of cyanotoxin triggers in recreational waters.
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
 
DECISION ID
162445
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Sodium
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 162445, Sodium
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341819
 
Pollutant: Sodium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Sodium.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
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, Lahontan Region).
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: Water Quality for Agriculture, published by the Food and Agriculture Organization of the United Nations in 1985, contains criteria protective of various agricultural uses of water, including irrigation of various types of crops and stock watering. At or below the sodium threshold of 69 mg/L, agricultural uses of water should not be limited.
Guideline Reference: Water Quality for Agriculture, Food and Agriculture Organization of the United Nations - Irrigation and Drainage Paper No. 29, Rev 1, Rome (1985)
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
Line of Evidence (LOE) for Decision ID 162445, Sodium
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341789
 
Pollutant: Sodium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Sodium.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
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, Lahontan Region).
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: Per the Drinking Water Standards and Health Advisories (USEPA 2012), the health advisory for sodium for individuals on a sodium-restricted diet is 20 mg/l.
Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
 
DECISION ID
170305
Region 6     
Virginia Lakes (Mono County)
 
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available
 
Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
 
 
Line of Evidence (LOE) for Decision ID 170305, Specific Conductivity
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341887
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for SpecificConductivity.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water designated as MUN shall not contain concentrations of chemical constituents in excess of the maximum contaminant level (MCL) or secondary maximum contaminant level (SMCL) based upon drinking water standards specified in Title 22 of the California Code of Regulations (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's 'Chemical Constituents' objective. The California Secondary MCL for specific conductivity is 900 uS/cm.
Guideline Reference: California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
 
DECISION ID
162446
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Sulfates
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 162446, Sulfates
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341938
 
Pollutant: Sulfates
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Sulfate.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Secondary MCL that is incorporated by reference in the Water Quality Control Plan, Lahontan Region for Sulfate 250 mg/L (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
 
DECISION ID
162447
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Turbidity
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 162447, Turbidity
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341979
 
Pollutant: Turbidity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Turbidity.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water designated as MUN shall not contain concentrations of chemical constituents in excess of the maximum contaminant level (MCL) or secondary maximum contaminant level (SMCL) based upon drinking water standards specified in Title 22 of the California Code of Regulations. The Lahontan Basin Plan also has regionwide turbidity objective for other beneficial uses that states: Waters shall be free of changes in turbidity that cause nuisance or adversely affect the water for beneficial uses. Increases in turbidity shall not exceed natural levels by more than 10%.
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: California Maximum Contaminant Levels (MCLs) apply to ambient surface waters under the Lahontan Basin Plan's 'Chemical Constituents' objective. The Secondary MCL for turbidity is 5 NTU. Calculation of a numeric objective for other beneficial uses requires comparison with upstream or other background data which may not be available as part of the data used for water quality assessment.
Guideline Reference: California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
 
DECISION ID
162444
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: pH
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
 
Regional Board Conclusion: Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.
 
Regional Board Decision 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. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation:
 
 
Line of Evidence (LOE) for Decision ID 162444, pH
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341671
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Lahontan Basin Plan's regionwide objective for pH states: 'In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis.'
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
Line of Evidence (LOE) for Decision ID 162444, pH
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 341701
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Aquatic Resources Survey (NARS) data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for pH. The objective for this pollutant requires background information that is currently unavailable, and therefore an assessment of water quality thresholds could not be made.
Data Reference: WQX from the NWQMP for the 2026 Integrated Report in Region 6
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The Lahontan Basin Plan's regionwide objective for pH states: 'In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units. For all other waters of the region, the pH shall not be depressed below 6.5 nor raised above 8.5 units. The Regional Board recognizes that some waters of the Region may have natural pH levels outside of the 6.5 to 8.5 range. Compliance with the pH objective for these waters will be determined on a case-by-case basis.'
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site: NARS_WQX-NLA12_CA-R13 (NLA12_CA-R13).
Temporal Representation: The samples were collected between the dates of 2012-07-13 and 2012-07-13
Environmental Conditions:
QAPP Information: SWAMP QAPrP
QAPP Information Reference(s): Generic SWAMP QAPrP
 
 
DECISION ID
78289
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Aldrin
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the guideline 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78289, Aldrin
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46055
 
Pollutant: Aldrin
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Aldrin. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: National Academy of Science guidelines (NAS 1972) establish a maximum Aldrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78290
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Chlordane
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the criteria/guidelines for both the COLD and COMM beneficial uses 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78290, Chlordane
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46066
 
Pollutant: Chlordane
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: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlordane, Total. One sample composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total chlordane was calculated as the sum of the following chlordane isomers: cis- and trans-chlordane, cis- and trans-nonachlor, and oxychlordane.
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Lahontan Region: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for total chlordane in fish tissue is 3.9 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference: Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. Samples were collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 78290, Chlordane
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46058
 
Pollutant: Chlordane
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Chlordane, Total. One sample composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total chlordane was calculated as the sum of the following chlordane isomers: cis- and trans-chlordane, cis- and trans-nonachlor, and oxychlordane.
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: National Academy of Science guidelines (NAS 1972) establish a maximum total Chlordane concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. Samples were collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78541
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the guidelines for both COLD and COMM beneficial uses 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78541, DDT (Dichlorodiphenyltrichloroethane)
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46056
 
Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDT, Total. One sample composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total DDT was calculated as the sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD.
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: National Academy of Science guidelines (NAS 1972) establish a maximum total DDT concentration of 1000 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. Samples were collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 78541, DDT (Dichlorodiphenyltrichloroethane)
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46064
 
Pollutant: Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)
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: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDT, Total. One sample composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total DDT was calculated as the sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD.
Data Reference: Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
  Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Lahontan Region: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life.
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for total DDT in fish tissue is 15 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference: Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. Samples were collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78291
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Dieldrin
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the guideline for COLD beneficial use; for this same sample, the data was not used because the reporting limit was above the objective for the COMM beneficial use 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78291, Dieldrin
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46065
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Dieldrin. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: National Academy of Science guidelines (NAS 1972) establish a maximum Dieldrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 78291, Dieldrin
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46075
 
Pollutant: Dieldrin
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Dieldrin. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). One sample was not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for dieldrin in fish tissue is 0.32 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference: Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78294
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Endrin
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the guidelines for both COMM and COLD beneficial uses 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78294, Endrin
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 45898
 
Pollutant: Endrin
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Endrin. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: National Academy of Science guidelines (NAS 1972) establish a maximum Endrin concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 78294, Endrin
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46011
 
Pollutant: Endrin
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: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Endrin. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for endrin in fish tissue is 660 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference: Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Guideline Reference: Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78132
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Heptachlor
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the guidelines 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78132, Heptachlor
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46030
 
Pollutant: Heptachlor
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Heptachlor. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: National Academy of Science guidelines (NAS 1972) establish a maximum Heptachlor concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78342
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Heptachlor epoxide
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one sample exceeded the guidelines for both COLD and COMM beneficial uses 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78342, Heptachlor epoxide
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46031
 
Pollutant: Heptachlor epoxide
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Heptachlor epoxide. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: National Academy of Science guidelines (NAS 1972) establish a maximum Heptachlor Epoxide concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 78342, Heptachlor epoxide
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46039
 
Pollutant: Heptachlor epoxide
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: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Heptachlor epoxide. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for heptachlor epoxide in fish tissue is 0.93 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference: Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Guideline Reference: Public Health Goal for Heptachlor and Heptachlor Epoxide in Drinking Water
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78343
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Hexachlorobenzene/ HCB
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78343, Hexachlorobenzene/ HCB
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46012
 
Pollutant: Hexachlorobenzene/ HCB
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: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Hexachlorobenzene. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for hexachlorobenzene in fish tissue is 2.8 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference: Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Guideline Reference: Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78344
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the guidelines for both COLD and COMM beneficial uses 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78344, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46020
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for HCH, gamma. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: National Academy of Science guidelines (NAS 1972) establish a maximum Lindane concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 78344, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46021
 
Pollutant: Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
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: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for HCH, gamma. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for lindane in fish tissue is 4.6 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference: Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Guideline Reference: Air Toxics Hotspots Program Risk Assessment Guidelines. Part ll Technical Support Document for Describing Available Cancer Potency Values.
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78394
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: Mirex
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the criteria 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78394, Mirex
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46048
 
Pollutant: Mirex
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 0
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 0 samples exceed the criterion for Mirex. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). One sample was not used in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy.
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for mirex in fish tissue is 0.28 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference: Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Guideline Reference: Expedited Cancer Potency Values and Proposed Regulatory Levels for Certain Proposition 65 Carcinogens.
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78493
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: PCBs (Polychlorinated biphenyls)
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the guidelines for both COLD and COMM benefiical uses 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78493, PCBs (Polychlorinated biphenyls)
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46057
 
Pollutant: PCBs (Polychlorinated biphenyls)
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: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for PCB, Total. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, Lahontan Region: 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.
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for polychlorinated biphenyls in fish tissue is 2.6 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day for a 30 year exposure over a 70-year lifetime. This constituent is a carcinogen therefore the risk level is set to one in a million. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference: Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 78493, PCBs (Polychlorinated biphenyls)
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46049
 
Pollutant: PCBs (Polychlorinated biphenyls)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for PCB, Total. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). Total PCB was assessed for as follows: PCB aroclors and congeners were summed separately and the sum that yielded the highest value was used for the assessment.
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: 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, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: National Academy of Science guidelines (NAS 1972) establish a maximum total PCB concentration of 500 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
 
DECISION ID
78542
Region 6     
Virginia Lakes (Mono County)
 
Pollutant: alpha-Endosulfan (Endosulfan 1)
Final Listing Decision: Do Not 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)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: 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 line of evidence is available in the administrative record to assess this pollutant. Zero 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. Zero of one samples exceeded the guidelines for both COLD and COMM beneficial uses 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.
 
Regional Board Decision Recommendation: This region was not assessed this cycle. All decisions have been carried over from the previous cycle and remain the same.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 78542, alpha-Endosulfan (Endosulfan 1)
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 45897
 
Pollutant: alpha-Endosulfan (Endosulfan 1)
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: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Endosulfan I. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: The modified OEHHA Fish Contaminant Goal for endosulfan (l and ll) in fish tissue is 13,000 ppb. This screening level assumes an average body weight of 70 kg and a consumption rate of 32 g/day. A cooking reduction factor of 1 is applied for skin-off fillets.
Guideline Reference: Development of Fish Contaminant Goals and Advisory Tissue Levels for Common Contaminants in California Sport Fish: Chlordane, DDTs, Dieldrin, Methylmercury, PCBs, Selenium, and Toxaphene
Guideline Reference: Guidance for Assessing Chemical Contaminant Data for Use In Fish Advisories Volume 1: Fish Sampling and Analysis
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments
 
Line of Evidence (LOE) for Decision ID 78542, alpha-Endosulfan (Endosulfan 1)
Region 6     
Virginia Lakes (Mono County)
 
LOE ID: 46076
 
Pollutant: alpha-Endosulfan (Endosulfan 1)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Fish fillet
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Water Board staff assessed SWAMP data for Virginia Lakes (Mono County) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Endosulfan I. One composite (5 fish per composite) was generated from one species: rainbow trout. Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009).
Data Reference: Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008
  Statewide Lakes Sportfish Contamination Study 2007 2008
  Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey
  Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable levels, using the most recent detection procedures available. There shall not be an increase in pesticide concentrations found in bottom sediments. There shall be no detectable increase in bioaccumulation of pesticides in aquatic life. (Water Quality Control Plan, Lahontan Region)
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline: National Academy of Science guidelines (NAS 1972) establish a maximum total Endosulfan concentration of 100 ug/Kg (wet weight) in tissue samples for protection of aquatic life from bioaccumulation of toxic substances.
Guideline Reference: National Academy of Sciences. Water Quality Criteria 1972. EPA-R3-73-033. Washington, D.C.: U.S. Environmental Protection Agency
 
Spatial Representation: Data for this line of evidence for Virginia Lakes (Mono County) was collected at 1 monitoring site [ Virginia Lakes - 630PVL031]. One sample was collected from 1 location. Individual sample locations consisted of an area within a given waterbody from which fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody (SWAMP, 2010). Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008).
Temporal Representation: Data was collected on a single day 10/18/2007.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: Samples were collected, processed, and analyzed in accordance with the methods described in Quality Assurance Project Plan "Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008).
QAPP Information Reference(s): Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments