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

Supporting Information

Regional Board 6 - Lahontan Region

Water Body Name: Scotts Lake
Water Body ID: CAL6332000020170914053315
Water Body Type: Lake & Reservoir
 
DECISION ID
102265
Region 6     
Scotts 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 of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. 0 of 1 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 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 does not satisfy the data quantity requirements of section 6.1.5 of the Policy.
3. 0 of 1 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 are 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:
 
 
Line of Evidence (LOE) for Decision ID 102265, Chloride
Region 6     
Scotts Lake
 
LOE ID: 96886
 
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: Data were collected in August 2012 as part of USEPA's National Lakes Assessment. One sample was collected and the chloride concentration recorded as 0.332 mg/L which attains the water quality objective.
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for the EPA National Lakes Assessment 2012.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The site specific objective for chloride in Scotts Lake, as referenced in the Lahontan Basin Plan table 3-14 and applied because the waterbody is tributary to the West Fork Carson River (headwaters to Hope Valley), is a mean of monthly means not to exceed 1.0 mg/L.
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data were collected from 633L12123.
Temporal Representation: Data were collected on one day in August 2012.
Environmental Conditions: Scotts Lake is small lake in northern Alpine County near the Tahoe Basin. The waterbody drains south to Hope Valley where it flows into the West Fork Carson River near Picketts Junction. The drainage is used for recreation year round.
QAPP Information: Data were collected in accordance with the USEPA NLA 2012 QAPP
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan
 
 
DECISION ID
102266
Region 6     
Scotts 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 of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. 0 of 1 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 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 does not satisfy the data quantity requirements of section 6.1.5 of the Policy.
3. 0 of 1 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 are 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:
 
 
Line of Evidence (LOE) for Decision ID 102266, Nitrate/Nitrite (Nitrite + Nitrate as N)
Region 6     
Scotts Lake
 
LOE ID: 98199
 
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 Scotts 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 the 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, Lahontan Region is 10.0 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(s) (633L12123)
Temporal Representation: The samples were collected between the dates of 2012-08-15 and 2012-08-15
Environmental Conditions:
QAPP Information: 2012 National Lakes Assessment Quality Assurance Project Plan
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan
 
 
DECISION ID
102267
Region 6     
Scotts 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 of evidence is necessary to assess listing status.

Two lines of evidence, one which assesses the available data for the AG beneficial use and one which assesses the available data for the MUN beneficial use, are available in the administrative record to assess this pollutant. 0 of 1 samples in each assessment 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 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 does not satisfy the data quantity requirements of section 6.1.5 of the Policy.
3. 0 of 1 samples in each beneficial use assessment 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 per beneficial use assessed are 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:
 
 
Line of Evidence (LOE) for Decision ID 102267, Sodium
Region 6     
Scotts Lake
 
LOE ID: 98112
 
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 Lakes Assessment 2012 data for Scotts Lake to determine beneficial use support and results are as follows: 0 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 the 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 (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(s) (633L12123)
Temporal Representation: The samples were collected between the dates of 2012-08-15 and 2012-08-15
Environmental Conditions:
QAPP Information: 2012 National Lakes Assessment Quality Assurance Project Plan
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan
 
Line of Evidence (LOE) for Decision ID 102267, Sodium
Region 6     
Scotts Lake
 
LOE ID: 97075
 
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 Lakes Assessment 2012 data for Scotts Lake to determine beneficial use support and results are as follows: 0 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 the 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 (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(s) (633L12123)
Temporal Representation: The samples were collected between the dates of 2012-08-15 and 2012-08-15
Environmental Conditions:
QAPP Information: 2012 National Lakes Assessment Quality Assurance Project Plan
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan
 
 
DECISION ID
102268
Region 6     
Scotts 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 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 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 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 does not satisfy the data quantity requirements of section 6.1.5 of the Policy.
3. 0 of 1 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 are 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:
 
 
Line of Evidence (LOE) for Decision ID 102268, Sulfates
Region 6     
Scotts Lake
 
LOE ID: 96887
 
Pollutant: Sulfates
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: Data were collected in August 2012 as part of USEPA's National Lakes Assessment. One sample was collected and the sulfates concentration recorded as 0.138 mg/L which attains the water quality objective.
Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for the EPA National Lakes Assessment 2012.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The site specific objective for sulfates in Scotts Lake, as referenced in the Lahontan Basin Plan table 3-14 and applied because the waterbody is tributary to the West Fork Carson River (headwaters to Hope Valley), is a mean of monthly means not to exceed 2.0 mg/L.
Objective/Criterion Reference: Water Quality Control Plan for the Lahontan Region (as amended)
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Data were collected from 633L12123.
Temporal Representation: Data were collected on one day in August 2012.
Environmental Conditions: Scotts Lake is small lake in northern Alpine County near the Tahoe Basin. The waterbody drains south to Hope Valley where it flows into the West Fork Carson River near Picketts Junction. The drainage is used for recreation year round.
QAPP Information: Data were collected in accordance with the USEPA NLA 2012 QAPP
QAPP Information Reference(s): 2012 National Lakes Assessment Quality Assurance Project Plan