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

# Supporting Information

## Regional Board 5 - Central Valley Region

Water Body Name: | Horse Creek (Rising Star Mine to Shasta Lake)
Water Body ID: | CAR5062001019980814101128
Water Body Type: | River & Stream

DECISION ID | 7556
Pollutant: | Copper
Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Revised
Sources: | Resource Extraction
Expected TMDL Completion Date: | 2020
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One lines of evidence are available in the administrative record to assess pollutant. One of 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 removing this water segment-pollutant combination from the 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 2 samples exceeded the water quality objective for total copper and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. A minimum sample size of 28 is required to make a delisting designation according to Table 4.1. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are 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 removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 7556

LOE ID: | 20651
Pollutant: | Copper
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | 0 of the 2 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Copper.
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: | Copper levels should not exceed 1300 ug/L (Department of Public Health Primary MCL)
Guideline Reference: | Compilation of Water Quality Goals - 2007 for toxicity data
Spatial Representation: | Samples were collected at Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from Oct 15 2003 to Oct 15 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: | 4231
Pollutant: | Copper
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference pre-2006 303(d)
Water Quality Objective/Criterion: | Unspecified
Objective/Criterion Reference: | Placeholder reference pre-2006 303(d)
Evaluation Guideline: | Unspecified
Guideline Reference: | Placeholder reference pre-2006 303(d)
Spatial Representation: | Unspecified
Temporal Representation: | Unspecified
Environmental Conditions: | Unspecified
QAPP Information: | Unspecified
QAPP Information Reference(s):
LOE ID: | 6771
Pollutant: | Copper
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 1
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | 1 of the 2 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Copper. The exceeded results are as follows: 10/15/2003 - a sample taken at Upper Horse Creek had a result of 11µg/L.
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) Total Copper levels should not exceed the calculated limit based on the formula: Criteria Maximum Concentration (1-hour Average, total)=(EXP(0.9422*LN(hardness)-1.7)) (CTR)
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
| Compilation of Water Quality Goals - 2007 for toxicity data
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from Oct 15 2003 to Oct 15 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 | 7558
Pollutant: | Zinc
Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Revised
Sources: | Resource Extraction
Expected TMDL Completion Date: | 2020
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for delisting under sections 4.1 of the Listing Policy. Under section 4.1 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 removing this water segment-pollution combination from the section 303(d) list. The recommendation is based on staff findings that only 2 samples are available and a minimum of 28 is needed for evaluation under section 4.1. 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 removed from the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: | N/A
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 7558

LOE ID: | 6773
Pollutant: | Zinc
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | 0 of the 2 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Zinc.
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) Total Zinc levels should not exceed the calculated limit based on the formula: Criteria Maximum Concentration=EXP((0.8473*LN(hardness))+0.884)(CTR)
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
| Compilation of Water Quality Goals - 2007 for toxicity data
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from Oct 15 2003 to Oct 15 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 | 9259
Pollutant: | Zinc
Final Listing Decision: | Do Not Delist from 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: | 2020
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for delisting under sections 4.1 of the Listing Policy. Under section 4.1 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 removing this water segment-pollution combination from the section 303(d) list. The recommendation is based on staff findings that only 2 samples are available and a minimum of 28 is needed for evaluation under section 4.1. 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 removed from the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 9259

LOE ID: | 6773
Pollutant: | Zinc
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | 0 of the 2 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Zinc.
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) Total Zinc levels should not exceed the calculated limit based on the formula: Criteria Maximum Concentration=EXP((0.8473*LN(hardness))+0.884)(CTR)
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
| Compilation of Water Quality Goals - 2007 for toxicity data
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from Oct 15 2003 to Oct 15 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 | 7558
Pollutant: | Zinc
Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Revised
Sources: | Resource Extraction
Expected TMDL Completion Date: | 2020
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for delisting under sections 4.1 of the Listing Policy. Under section 4.1 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 removing this water segment-pollution combination from the section 303(d) list. The recommendation is based on staff findings that only 2 samples are available and a minimum of 28 is needed for evaluation under section 4.1. 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 removed from the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.
SWRCB Board Decision / Staff Recommendation: | N/A
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 7558

LOE ID: | 4233
Pollutant: | Zinc
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference pre-2006 303(d)
Water Quality Objective/Criterion: | Unspecified
Objective/Criterion Reference: | Placeholder reference pre-2006 303(d)
Evaluation Guideline: | Unspecified
Guideline Reference: | Placeholder reference pre-2006 303(d)
Spatial Representation: | Unspecified
Temporal Representation: | Unspecified
Environmental Conditions: | Unspecified
QAPP Information: | Unspecified
QAPP Information Reference(s):
LOE ID: | 20812
Pollutant: | Zinc
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | 0 of the 2 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Zinc.
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: | Zinc levels should not exceed 5000 ug/L (Department of Public Health Secondary MCL)
Guideline Reference: | SWAMP data entered by SWRCB into BDAT database
Spatial Representation: | Samples were collected at Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from Oct 15 2003 to Oct 15 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 | 10078
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
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 2 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 2 has 2 or more samples that exceed the evaluation criteria.
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 10078

LOE ID: | 20603
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | 0 of the 2 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Chloride.
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: | Chloride levels should not exceed 250 mg/L (USEPA Maximum Contaminant Level)
Guideline Reference: | Compilation of Water Quality Goals - 2007 for toxicity data
Spatial Representation: | Samples were collected at Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from Oct 15 2003 to Oct 15 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 | 10080
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 listing under sections 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Data is available from 3 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 4 of 21 available concentrations exceeded the USEPA E. coli Objective for Municipal Use and this does not exceed the allowable frequency using Table 3.2 of the Listing Policy. The recommendation is based on staff findings that 3 of 21 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. The recommendation is based on staff findings that 4 of 21 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. 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 10080

LOE ID: | 7145
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Non-Contact Recreation
Number of Samples: | 21
Number of Exceedances: | 3
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | 3 of the 21 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation guideline for E.Coli Bacteria. The exceeded results are as follows: 5/26/2004 - a sample taken at Middle Horse Creek had a result of 488MPN/100 mL. 6/16/2004 - a sample taken at Middle Horse Creek had a result of 816MPN/100 mL. 6/21/2005 - a sample taken at Upper Horse Creek had a result of 687MPN/100 mL.
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 Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from May 26 2004 to Aug 16 2005
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: | 6910
Pollutant: | Escherichia coli (E. Coli)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 21
Number of Exceedances: | 4
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | Four of the 21 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation guideline for E.Coli Bacteria. The exceeded results are as follows: 5/26/2004 - a sample taken at Middle Horse Creek had a result of 488MPN/100 mL. 6/16/2004 - a sample taken at Middle Horse Creek had a result of 816MPN/100 mL. 5/18/2005 - a sample taken at Middle Horse Creek had a result of 345MPN/100 mL. 6/21/2005 - a sample taken at Upper Horse Creek had a result of 687MPN/100 mL.
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 Guideline)
Guideline Reference: | Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
Spatial Representation: | Samples were collected at Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from May 26 2004 to Aug 16 2005
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 | 10081
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
Weight of Evidence: | 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 21 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 21 has 5 or more samples that exceed the evaluation criteria.
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 10081

LOE ID: | 20852
Pollutant: | Specific Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 21
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | 0 of the 21 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Specific Conductivity.
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: | The water quality objective used was the California Secondary MCL recommended level of 900 uS/cm. The Basin Plan includes chemical constituent water quality objectives that include (by reference) secondary maximum contaminant levels (MCLs) protective of MUN (CVRWQCB, 2007a).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 concentration was used as it is intended to be protective of all drinking water uses.
Guideline Reference: | Compilation of Water Quality Goals - 2007 for toxicity data
Spatial Representation: | Samples were collected at Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from Oct 15 2003 to Apr 20 2005
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 | 10082
Pollutant: | Total Dissolved Solids
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 2 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 2 has 2 or more samples that exceed the evaluation criteria.
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 10082

LOE ID: | 20729
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Asses Water Quality: | 0 of the 2 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for Total Dissolved Solids.
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: | The water quality objective used was the California Secondary MCL recommended level of 500 mg/L. The Basin Plan includes chemical constituent water quality objectives that include (by reference) secondary maximum contaminant levels (MCLs) protective of MUN (CVRWQCB, 2007a).The secondary MCLs for TDS provide a range of values including a recommended level (500 mg/L), upper level (1000 mg/L) and a short-term level (1500 mg/L). The recommended concentration was used as it is intended to be protective of all drinking water uses.
Guideline Reference: | Compilation of Water Quality Goals - 2007 for toxicity data
Spatial Representation: | Samples were collected at Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from Oct 15 2003 to Oct 15 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 | 9258
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 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 sufficient justification for placing this water segment-pollution combination on the section 303(d) list. The recommendation is based on staff findings that 7 of 29 available concentrations exceeded the water quality objective and this does 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 29 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 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 9258

LOE ID: | 6772
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 29
Number of Exceedances: | 7
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | 7 of the 29 samples collected by the Surface Water Ambient Monitoring Program exceeded the evaluation objective for pH. The exceeded results are as follows: 10/15/2003 - a sample taken at Middle Horse Creek had a result of 8.98none. 7/12/2004 - a sample taken at Middle Horse Creek had a result of 8.78none. 10/15/2003 - a sample taken at Upper Horse Creek had a result of 8.88none. 4/24/2004 - a sample taken at Upper Horse Creek had a result of 8.94none. 7/12/2004 - a sample taken at Upper Horse Creek had a result of 9.03none. 6/21/2005 - a sample taken at Upper Horse Creek had a result of 8.85none. 8/16/2005 - a sample taken at Upper Horse Creek had a result of 8.56none.
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 8.5 (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 Middle Horse Creek. Samples were collected at Upper Horse Creek.
Temporal Representation: | The samples were collected from Oct 15 2003 to Aug 16 2005
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 | 7555
Pollutant: | Cadmium
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Original
Sources: | Resource Extraction
Expected TMDL Completion Date: | 2020
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.
RWQCB Board Decision / Staff Recommendation: | No new data were assessed for 2008. The decision has not changed.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 7555

LOE ID: | 4230
Pollutant: | Cadmium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference pre-2006 303(d)
Water Quality Objective/Criterion: | Unspecified
Objective/Criterion Reference: | Placeholder reference pre-2006 303(d)
Evaluation Guideline: | Unspecified
Guideline Reference: | Placeholder reference pre-2006 303(d)
Spatial Representation: | Unspecified
Temporal Representation: | Unspecified
Environmental Conditions: | Unspecified
QAPP Information: | Unspecified
QAPP Information Reference(s):

DECISION ID | 7557
Pollutant: | Lead
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006)
Revision Status | Original
Sources: | Resource Extraction
Expected TMDL Completion Date: | 2020
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.
RWQCB Board Decision / Staff Recommendation: | No new data were assessed for 2008. The decision has not changed.
SWRCB Board Decision / Staff Recommendation: |
USEPA Decision: |

Lines of Evidence (LOEs) for Decision ID 7557

LOE ID: | 4232
Pollutant: | Lead
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Warm Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Asses Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference pre-2006 303(d)
Water Quality Objective/Criterion: | Unspecified
Objective/Criterion Reference: | Placeholder reference pre-2006 303(d)
Evaluation Guideline: | Unspecified
Guideline Reference: | Placeholder reference pre-2006 303(d)
Spatial Representation: | Unspecified
Temporal Representation: | Unspecified
Environmental Conditions: | Unspecified
QAPP Information: | Unspecified
QAPP Information Reference(s):