Final California 2024 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 1 - North Coast Region

Water Body Name: Mount Dome Hydrologic Subarea, Indian Tom Lake
Water Body ID: CAL1059106020171003027695
Water Body Type: Lake & Reservoir
 
DECISION ID
104631
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
Pollutant: Ammonia
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: "This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the 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 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. None of the one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
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 104631, Ammonia
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
LOE ID: 102757
 
Pollutant: Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Total
 
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 Lakes Assessment 2012 data for Mount Dome Hydrologic Subarea, Indian Tom Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Ammonia as N.
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for EPA National Lakes Assessment 2012 .
 
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 (North Coast Regional Water Quality Control Board).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
Evaluation Guideline: The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L
Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories
 
Spatial Representation: The samples were collected at 1 monitoring site(s) (105L12208)
Temporal Representation: The samples were collected between the dates of 2012-08-21 and 2012-08-21
Environmental Conditions:
QAPP Information: Quality Assurance Project Plan for EPA National Lakes Assessment 2012
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan
 
 
DECISION ID
104629
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
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: "This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the 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 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. None of the one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 3.2.
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 104629, Chloride
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
LOE ID: 102746
 
Pollutant: Chloride
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 Lakes Assessment 2012 data for Mount Dome Hydrologic Subarea, Indian Tom Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Chloride.
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for EPA National Lakes Assessment 2012 .
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The secondary maximum contaminant level listed in Table 64449-B for chloride is 250 mg/L.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s) (105L12208)
Temporal Representation: The samples were collected between the dates of 2012-08-21 and 2012-08-21
Environmental Conditions:
QAPP Information: Quality Assurance Project Plan for EPA National Lakes Assessment 2012
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan
 
 
DECISION ID
104630
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
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: "This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the 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 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. None of the one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
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 104630, Nitrate/Nitrite (Nitrite + Nitrate as N)
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
LOE ID: 118968
 
Pollutant: Nitrate/Nitrite (Nitrite + Nitrate as N)
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 Lakes Assessment 2012 data for Mount Dome Hydrologic Subarea, Indian Tom Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Nitrate + Nitrite as N.
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for EPA National Lakes Assessment 2012 .
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The California Maximum Contaminant Level for nitrate + nitrite (as N) that is incorporated by reference in the Water Quality Control Plan, North Coast Basin is 10.0 mg/L (Water Quality Control Plan, North Coast Basin).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s) (105L12208)
Temporal Representation: The samples were collected between the dates of 2012-08-21 and 2012-08-21
Environmental Conditions:
QAPP Information: Quality Assurance Project Plan for EPA National Lakes Assessment 2012
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan
 
 
DECISION ID
103859
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line(s) of evidence are necessary to assess listing status.

Two lines of evidence are available in the administrative record to assess this pollutant. One of one samples exceed the objective for the MUN beneficial use(s).

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. One of one samples exceed the objective for the MUN beneficial use and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 3.2.
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 103859, Sodium
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
LOE ID: 118957
 
Pollutant: Sodium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Lakes Assessment 2012 data for Mount Dome Hydrologic Subarea, Indian Tom Lake to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality standard for Sodium.
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for EPA National Lakes Assessment 2012 .
 
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 (North Coast Regional Water Quality Control Board).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
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(s) (105L12208)
Temporal Representation: The samples were collected between the dates of 2012-08-21 and 2012-08-21
Environmental Conditions:
QAPP Information: Quality Assurance Project Plan for EPA National Lakes Assessment 2012
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 103859, Sodium
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
LOE ID: 118946
 
Pollutant: Sodium
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Dissolved
 
Beneficial Use: Agricultural Supply
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Water Board staff assessed EPA National Lakes Assessment 2012 data for Mount Dome Hydrologic Subarea, Indian Tom Lake to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality standard for Sodium.
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for EPA National Lakes Assessment 2012 .
 
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 (North Coast Regional Water Quality Control Board).
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
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(s) (105L12208)
Temporal Representation: The samples were collected between the dates of 2012-08-21 and 2012-08-21
Environmental Conditions:
QAPP Information: Quality Assurance Project Plan for EPA National Lakes Assessment 2012
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan
 
 
DECISION ID
104648
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
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: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

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

None of the samples exceed the 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 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. None of the one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 26 samples is needed to determine if a beneficial use is fully supported using table 3.2.
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 104648, Sulfates
Region 1     
Mount Dome Hydrologic Subarea, Indian Tom Lake
 
LOE ID: 110929
 
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 Lakes Assessment 2012 data for Mount Dome Hydrologic Subarea, Indian Tom Lake to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Sulfate.
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for EPA National Lakes Assessment 2012 .
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The secondary maximum contaminant level listed in Table 64449-B for sulfate is 250 mg/L.
Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The samples were collected at 1 monitoring site(s) (105L12208)
Temporal Representation: The samples were collected between the dates of 2012-08-21 and 2012-08-21
Environmental Conditions:
QAPP Information: Quality Assurance Project Plan for EPA National Lakes Assessment 2012
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan