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

# Supporting Information

## Regional Board 5 - Central Valley Region

Water Body Name: | Isabella Lake
Water Body ID: | CAL5542101020020418145333
Water Body Type: | Lake & Reservoir

DECISION ID | 9415
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
Weight of Evidence: | 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 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 52 available concentrations exceeded the water quality objective and this does not exceed the allowable frequency using Table 3.1 of the Listing Policy. Table 3.1 of the listing policy recommends listing if a sample size of 52 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 9415

LOE ID: | 8828
Pollutant: | Ammonia
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 52
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Zero of the 52 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
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: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | 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 Boulder Gulch. Samples were collected at Camp 9. Samples were collected at French Gulch. Samples were collected at Hanning Flat. Samples were collected at Main Dam. Samples were collected at Pioneer Point. Samples were collected at So. Fork Rec.. Samples were collected at Tille Creek. Samples were collected at Wofford Heights.
Temporal Representation: | The samples were collected from Jun 20 2002 to May 25 2004
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 | 10380
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
Weight of Evidence: | 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 22 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 22 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 10380

LOE ID: | 20862
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 22
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | 0 of the 22 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for E.Coli Bacteria.
Data Reference: | SWAMP data entered by SWRCB into BDAT database
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: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | 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 Boulder Gulch. Samples were collected at Camp 9. Samples were collected at French Gulch. Samples were collected at Hanning Flat. Samples were collected at Main Dam. Samples were collected at Pioneer Point. Samples were collected at So. Fork Rec.. Samples were collected at Tille Creek. Samples were collected at Wofford Heights.
Temporal Representation: | The samples were collected from Mar 28 2002 to Jun 25 2003
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):
LOE ID: | 20861
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 22
Number of Exceedances: | 0
Data and Information Type: | PATHOGEN MONITORING
Data Used to Assess Water Quality: | 0 of the 22 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for E.Coli Bacteria.
Data Reference: | SWAMP data entered by SWRCB into BDAT database
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: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | E.Coli Bacteria levels should not exceed 235 MPN/100 mL in any single sample (USEPA E.Coli objective)
Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation: | Samples were collected at Boulder Gulch. Samples were collected at Camp 9. Samples were collected at French Gulch. Samples were collected at Hanning Flat. Samples were collected at Main Dam. Samples were collected at Pioneer Point. Samples were collected at So. Fork Rec.. Samples were collected at Tille Creek. Samples were collected at Wofford Heights.
Temporal Representation: | The samples were collected from Mar 28 2002 to Jun 25 2003
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 | 9417
Pollutant: | Nitrate as Nitrate (NO3)
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
Weight of Evidence: | 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 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 9 available concentrations exceeded the water quality objective and this does not exceed the allowable frequency using Table 3.1 of the Listing Policy. Table 3.1 of the listing policy recommends listing if a sample size of 9 has 2 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.
RWQCB Board Decision / Staff 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.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 9417

LOE ID: | 8830
Pollutant: | Nitrate as Nitrate (NO3)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 9
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Zero of the 9 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation guideline for Nitrate-N.
Data Reference: | SWAMP data entered by SWRCB into BDAT database
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: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: | Nitrate-N levels should not to exceed 100 mg/L (USEPA National Ambient Water Quality Objective)
Guideline Reference: | National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology. 4304T The Blue Book
Spatial Representation: | Samples were collected at Boulder Gulch. Samples were collected at Camp 9. Samples were collected at French Gulch. Samples were collected at Hanning Flat. Samples were collected at Main Dam. Samples were collected at Pioneer Point. Samples were collected at So. Fork Rec.. Samples were collected at Tille Creek. Samples were collected at Wofford Heights.
Temporal Representation: | The samples were collected from Jun 20 2002 to Jun 25 2003
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 | 15951
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
Weight of Evidence: | 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. Ten 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. Ten of 58 dissolved oxygen samples fell below the 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.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15951

LOE ID: | 8829
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 58
Number of Exceedances: | 10
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Ten of the 58 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Dissolved Oxygen. The exceeded results are as follows: 12/11/2002 - a sample taken at Boulder Gulch had a result of 5.24mg/L. 9/17/2002 - a sample taken at French Gulch had a result of 6.53mg/L. 12/11/2002 - a sample taken at French Gulch had a result of 4.2mg/L. 6/19/2002 - a sample taken at Hanning Flat had a result of 6.91mg/L. 12/11/2002 - a sample taken at Hanning Flat had a result of 5.91mg/L. 9/17/2002 - a sample taken at Main Dam had a result of 6.03mg/L. 12/11/2002 - a sample taken at Main Dam had a result of 4.72mg/L. 12/11/2002 - a sample taken at Pioneer Point had a result of 4.46mg/L. 12/11/2002 - a sample taken at So. Fork Rec. had a result of 5.21mg/L. 12/11/2002 - a sample taken at Tille Creek had a result of 5.49mg/L.
Data Reference: | SWAMP data entered by SWRCB into BDAT database
Water Quality Objective/Criterion: | The Basin Plan Objective sets the minimum Dissolved Oxygen content at 7 mg/L
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at Boulder Gulch. Samples were collected at Camp 9. Samples were collected at French Gulch. Samples were collected at Hanning Flat. Samples were collected at Main Dam. Samples were collected at Pioneer Point. Samples were collected at So. Fork Rec.. Samples were collected at Tille Creek. Samples were collected at Wofford Heights.
Temporal Representation: | The samples were collected from Mar 28 2002 to May 25 2004
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 | 15952
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
Weight of Evidence: | 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. Thirty-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. Thirty-seven of 64 samples exceeded the pH 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.
RWQCB Board Decision / Staff Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 15952

LOE ID: | 8827
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 64
Number of Exceedances: | 37
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Thirty-seven of the 64 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for pH.
Data Reference: | SWAMP data entered by SWRCB into BDAT database
Water Quality Objective/Criterion: | pH levels should not be lower than 6.5 or higher than 8.3 (Basin Plan Objective)
Objective/Criterion Reference: | Central Valley Regional Water Quality Control Board. Water Quality Control Plan (Basin Plan) for the California Regional Water Quality Control Board - Central Valley Region
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at Boulder Gulch. Samples were collected at Camp 9. Samples were collected at French Gulch. Samples were collected at Hanning Flat. Samples were collected at Main Dam. Samples were collected at Pioneer Point. Samples were collected at So. Fork Rec.. Samples were collected at Tille Creek. Samples were collected at Wofford Heights.
Temporal Representation: | The samples were collected from Mar 28 2002 to May 25 2004
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):