Final California 2010 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name: Hensley Lake
Water Body ID: CAL5393201020020702142618
Water Body Type: Lake & Reservoir
 
DECISION ID
10075
Region 5     
Hensley 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 listing under sections 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Data is available from 2 lines of evidence for this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification for placing this water segment-pollution combination on the section 303(d) list. The recommendation is based on staff findings that 0 of 8 available concentrations exceeded the USEPA Health Advisory for Ammonia and this does not exceed the allowable frequency using Table 3.1 of the Listing Policy. The recommendation is based on staff findings that 0 of 8 available concentrations exceeded the USEPA Freshwater Aquatic Life Protection Criteria Maximum Concentration and this does not exceed the allowable frequency using Table 3.1 of the Listing Policy. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 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 because applicable water quality standards are not being exceeded.
 
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.
 
USEPA Action (if applicable):
 
 
Line of Evidence (LOE) for Decision ID 10075, Ammonia
Region 5     
Hensley Lake
 
LOE ID: 6765
 
Pollutant: Ammonia
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: 0 of the 8 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation guideline for Ammonia.
Data Reference: SWAMP data entered by SWRCB into BDAT database
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CRWQCB, 2006)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Ammonia levels should not to exceed the calculated limit. Freshwater Aquatic Life Protection (Salmonid present) Criteria Maximum Concentration (CMC) (1-hour Average (mg N/L)) calculated based on the following formula: CMC = (0.275/(1 + 107.204-pH)) + (39.0/(1 + 10pH-7.204)) which incorporates pH (US EPA, 2005: Appendix C)
Guideline Reference: 1999 Update of Ambient Water Quality Criteria for Ammonia
 
Spatial Representation: Samples were collected at Hensley Lake - Andy's Cove. Samples were collected at Hensley Lake - inflow. Samples were collected at Hensley Lake - outflow. Samples were collected at Hensley Lake - Restroom #7 to east.
Temporal Representation: The samples were collected from Aug 21 2001 to Oct 16 2001
Environmental Conditions:
QAPP Information: Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 10075, Ammonia
Region 5     
Hensley Lake
 
LOE ID: 21120
 
Pollutant: Ammonia
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 8
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: 0 of the 8 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Ammonia.
Data Reference: SWAMP data entered by SWRCB into BDAT database
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CRWQCB, 2006)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Ammonia levels should not exceed 30 mg/L (USEPA Health Advisory)
Guideline Reference: 2006 edition of the drinking water standards and health advisories. EPA 822-R-03-013
 
Spatial Representation: Samples were collected at Hensley Lake - Andy's Cove. Samples were collected at Hensley Lake - inflow. Samples were collected at Hensley Lake - North end of Andy's Cove. Samples were collected at Hensley Lake - outflow. Samples were collected at Hensley Lake - Restroom #7 to east.
Temporal Representation: The samples were collected from Aug 21 2001 to Oct 16 2001
Environmental Conditions:
QAPP Information: Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):
 
 
DECISION ID
10076
Region 5     
Hensley Lake
 
Pollutant: Escherichia coli (E. coli)
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 section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status.

One line of evidence are available in the administrative record to assess this pollutant. None 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. None of 13 available concentrations exceeded the USEPA E. coli Objective for Water Contact Recreation and this does not exceed the allowable frequency using Table 3.2 of the Listing Policy. In addition, 0 of 13 available concentrations exceeded the USEPA E. coli Objective for Non-Contact Recreation and this does not exceed the allowable frequency using Table 3.2 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: 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 because applicable water quality standards are not being exceeded.
 
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.
 
USEPA Action (if applicable):
 
 
Line of Evidence (LOE) for Decision ID 10076, Escherichia coli (E. coli)
Region 5     
Hensley Lake
 
LOE ID: 7142
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Non-Contact Recreation
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Zero of the 13 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation guideline for E.Coli Bacteria.
Data Reference: SWAMP data entered by SWRCB into BDAT database
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CRWQCB, 2006)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: E.Coli Bacteria levels should not exceed 409 MPN/100 mL in any single sample (USEPA E.Coli Guideline)
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Samples were collected at Hensley Lake - Andy's Cove. Samples were collected at Hensley Lake - inflow. Samples were collected at Hensley Lake - North end of Andy's Cove. Samples were collected at Hensley Lake - outflow. Samples were collected at Hensley Lake - Restroom #7 to east.
Temporal Representation: The samples were collected from Aug 21 2001 to Jun 27 2002
Environmental Conditions:
QAPP Information: Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 10076, Escherichia coli (E. coli)
Region 5     
Hensley Lake
 
LOE ID: 6909
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: Zero of the 13 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation guideline for E.Coli Bacteria.
Data Reference: SWAMP data entered by SWRCB into BDAT database
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. (CRWQCB, 2006)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: E.Coli Bacteria levels should not exceed 235 MPN/100 mL in any single sample (USEPA E.Coli Guideline)
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: Samples were collected at Hensley Lake - Andy's Cove. Samples were collected at Hensley Lake - inflow. Samples were collected at Hensley Lake - North end of Andy's Cove. Samples were collected at Hensley Lake - outflow. Samples were collected at Hensley Lake - Restroom #7 to east.
Temporal Representation: The samples were collected from Aug 21 2001 to Jun 27 2002
Environmental Conditions:
QAPP Information: Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):
 
 
DECISION ID
10077
Region 5     
Hensley Lake
 
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: This pollutant is being considered for listing under sections 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Data is available from 1 line of evidence for this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is not sufficient justification for placing this water segment-pollution combination on the section 303(d) list. The recommendation is based on staff findings that 0 of 13 available concentrations exceeded the water quality objective and this does not exceed the allowable frequency using Table 3.2 of the Listing Policy. Table 3.2 of the listing policy recommends listing if a sample size of 13 has 5 or more samples that exceed the evaluation criteria.

The data used satisfies the data quality requirements of section 6.1.4 of the Policy. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 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 because applicable water quality standards are not being exceeded.
 
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.
 
USEPA Action (if applicable):
 
 
Line of Evidence (LOE) for Decision ID 10077, Specific Conductivity
Region 5     
Hensley Lake
 
LOE ID: 20451
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 13
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of the 13 samples collected by the Surface Water Ambient Monitoring Program exceeded the "recommended" Secondary MCL of 900 uS/cm for electrical conductivity
Data Reference: SWAMP data entered by SWRCB into BDAT database
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The secondary MCLs for electrical conductivity provide a range of values including a recommended level (900 uS/cm), upper level (1600 uS/cm) and a short-term level (2200 uS/cm). The “recommended” level of 900 uS/cm was used as it is intended to be protective of all drinking water uses
Objective/Criterion Reference: California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected from Hensley Lake at Andy's Cove, at Hensley Lake inflow, at Hensley Lake outflow, and at Restroom #7 to east
Temporal Representation: The samples were collected between August 21, 2001 and June 27, 2002
Environmental Conditions:
QAPP Information: Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):
 
 
DECISION ID
17961
Region 5     
Hensley Lake
 
Pollutant: Mercury
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
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. Twenty-one of the samples exceed the water quality objective.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Twenty-one of 24 samples exceed the water quality objective and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: N/A
 
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 be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 17961, Mercury
Region 5     
Hensley Lake
 
LOE ID: 31054
 
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: 24
Number of Exceedances: 21
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Fish were collected for tissue analysis at two locations from Hensley Lake. A total of 24 sample composites were generated from two species: Largemouth Bass (22) and Common Carp (2). 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). A total of 21 out of 24 samples exceeded the OHHEA fish tissue screening value for human health.
Data Reference: Data associated with report entitled: 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
  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: All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. The objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances.
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline: Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 0.3 mg/kg to protect human health when consuming fish (OEHHA, 1999).
Guideline Reference: Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment
 
Spatial Representation: Samples were collected from two locations in Hensley Lake. As discussed in the Lakes and Reservoirs Report (SWAMP, 2009), individual sample locations consisted of an area within a given waterbody with an approximate one-mile diameter, from which multiple fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody. 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: Samples were collected on May 24, 2007 and August 28, 2007
Environmental Conditions: There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these 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
15942
Region 5     
Hensley Lake
 
Pollutant: Oxygen, Dissolved
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the 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 are available in the administrative record to assess this pollutant. Six of the samples exceed the water quality objective.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Six of 13 samples fell below the dissolved oxygen objective outlined in the Basin Plan and this exceeds the allowable frequency listed in Table 3.2 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: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
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.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 15942, Oxygen, Dissolved
Region 5     
Hensley Lake
 
LOE ID: 6768
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 13
Number of Exceedances: 6
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: 6 of the 13 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Dissolved Oxygen. The exceeded results are as follows: 8/21/2001 - a sample taken at Hensley Lake - Andy's Cove had a result of 4.6mg/L. 10/16/2001 - a sample taken at Hensley Lake - Andy's Cove had a result of 3.71mg/L. 8/21/2001 - a sample taken at Hensley Lake - inflow had a result of 4.82mg/L. 10/16/2001 - a sample taken at Hensley Lake - inflow had a result of 3.37mg/L. 10/16/2001 - a sample taken at Hensley Lake - outflow had a result of 3.26mg/L. 10/16/2001 - a sample taken at Hensley Lake - Restroom #7 to east had a result of 3.41mg/L.
Data Reference: SWAMP data entered by SWRCB into BDAT database
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The Basin Plan Objective sets the minimum Dissolved Oxygen content at 5 mg/L
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at Hensley Lake - Andy's Cove. Samples were collected at Hensley Lake - inflow. Samples were collected at Hensley Lake - North end of Andy's Cove. Samples were collected at Hensley Lake - outflow. Samples were collected at Hensley Lake - Restroom #7 to east.
Temporal Representation: The samples were collected from Aug 21 2001 to Jun 27 2002
Environmental Conditions:
QAPP Information: Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):
 
 
DECISION ID
15943
Region 5     
Hensley Lake
 
Pollutant: pH
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the 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 are available in the administrative record to assess this pollutant. Seven of the samples exceed the water quality objective.

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

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. Seven of 13 samples exceed the pH objective found in the Basin Plan and this exceeds the allowable frequency listed in Table 3.2 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: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
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.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 15943, pH
Region 5     
Hensley Lake
 
LOE ID: 6769
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Warm Freshwater Habitat
 
Number of Samples: 13
Number of Exceedances: 7
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: 7 of the 13 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for pH. The exceeded results are as follows: 8/21/2001 - a sample taken at Hensley Lake - Andy's Cove had a result of 8.94-. 10/16/2001 - a sample taken at Hensley Lake - Andy's Cove had a result of 9.38-. 6/27/2002 - a sample taken at Hensley Lake - Andy's Cove had a result of 8.5-. 8/21/2001 - a sample taken at Hensley Lake - outflow had a result of 8.96-. 10/16/2001 - a sample taken at Hensley Lake - outflow had a result of 8.59-. 8/21/2001 - a sample taken at Hensley Lake - Restroom #7 to east had a result of 8.69-. 6/27/2002 - a sample taken at Hensley Lake - Restroom #7 to east had a result of 8.5-.
Data Reference: SWAMP data entered by SWRCB into BDAT database
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: pH levels should not be lower than 6.5 or higher than 8.3 (Basin Plan Objective)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at Hensley Lake - Andy's Cove. Samples were collected at Hensley Lake - inflow. Samples were collected at Hensley Lake - North end of Andy's Cove. Samples were collected at Hensley Lake - outflow. Samples were collected at Hensley Lake - Restroom #7 to east.
Temporal Representation: The samples were collected from Aug 21 2001 to Jun 27 2002
Environmental Conditions:
QAPP Information: Monitoring was conducted in accordance with the State Water Resources Control Board's Quality Assurance Program Plan for the State of California's Surface Water Ambient Monitoring Program.
QAPP Information Reference(s):