Final California 2018 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name: Rock Creek (Nevada County)
Water Body ID: CAR5173203320110209161055
Water Body Type: River & Stream
 
DECISION ID
92750
Region 5     
Rock Creek (Nevada County)
 
Pollutant: Indicator Bacteria
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.
Four lines of evidence are available in the administrative record to assess this pollutant. One of 28 water samples exceeds the evaluation guideline for E. coli and none of the 28 water samples exceed the evaluation guideline for total coliform.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. One of 28 water samples exceeds the evaluation guideline for E. coli and none of the 28 water samples exceed the evaluation guideline for total coliform, and this does not exceed 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 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.
 
 
Line of Evidence (LOE) for Decision ID 92750, Indicator Bacteria
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 69440
 
Pollutant: Escherichia coli (E. coli)
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PATHOGEN MONITORING
Data Used to Assess Water Quality: SWAMP data indicates that 0 of 6 sample results exceed the evaluation guideline value for Escherichia coli.
Data Reference: RWB5 Safe to Swim FY0708 FY0809
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
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: The U.S. EPA recommended objective for a single-sample maximum allowable density of E. coli in freshwater designated-beach areas is 235 MPN/100mL.
Guideline Reference: 40 CFR Part 131 Water Quality Standards for Coastal and Great Lakes Recreation Waters; Final Rule [Federal Register / Vol. 69, No. 220]
 
Spatial Representation: Data for this line of evidence was collected at two monitoring sites [ Rock Creek Above Lake Vera - 516NEV904, Rock Creek Below Lake Vera - 516NEV905]
Temporal Representation: Data was collected over the time period 8/27/2008-9/3/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 92750, Indicator Bacteria
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 69441
 
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: 1
 
Data and Information Type: Not Specified
Data Used to Assess Water Quality: One of the 22 samples exceeded the E. coli objective.
Data Reference: Data in Yuba: metal, 2000-2007 and conventional, 2000-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River and San Joaquin River Basins)
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: The E. coli concentration shall not exceed more than 235/100 ml. USEPA Ambient Water Quality Criteria for Bacteria - 1986.
Guideline Reference: Ambient Water Quality Criteria for Bacteria - 1986. EPA440/5-84-002
 
Spatial Representation: The samples were collected at SYRCL monitoring station 22, Lower Rock Creek and station 34, Upper Rock Creek. WBID: CAR5173203320110209161055
Temporal Representation: The samples were collected monthly between 2001 and 2006.
Environmental Conditions:
QAPP Information: This data was collected under the Water Monitoring Quality Assurance Project Plan for the Yuba Watershed Council Monitoring Committee. Rev 1.3. qa12
QAPP Information Reference(s):
 
 
DECISION ID
86836
Region 5     
Rock Creek (Nevada County)
 
Pollutant: Iron
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1, one line(s) of evidence are necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. One of the eight samples exceed the Evaluation Guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. One of eight samples exceeded Evaluation Guideline and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1.
4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.
 
State Board Review of Regional Board Conclusion and Recommendation:
 
State Board Decision Recommendation: After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.
 
 
Line of Evidence (LOE) for Decision ID 86836, Iron
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 69442
 
Pollutant: Iron
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: Not Recorded
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 8
Number of Exceedances: 1
 
Data and Information Type: Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: One of the eight samples exceeded the recommended guideline of 1,000 ug/L.
Data Reference: Data in Yuba: metal, 2000-2007 and conventional, 2000-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: Waters shall not contain chemical constituents in concentrations that adversely affect beneficial uses.
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: National Recommended Water Quality Criteria Continuous Concentrations are intended protect freshwater aquatic organisms from chronic exposures and are expressed as 4-day average concentrations. The recommended guideline for Iron is 1,000 ug/L.
Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
 
Spatial Representation: The samples were collected from station 22 (Lower Rock Creek) and 34 (Upper Rock Creek).
Temporal Representation: Samples were collected from stations 22 and 34 in 2005 and 2006; and also from station 34 in 2007.
Environmental Conditions:
QAPP Information: Samples were collected and analyzed in accordance with Water Monitoring Quality Assurance Project Plan prepared for the Yuba Watershed Monitoring Committee (Revision 1.3) dated June 30, 2008.
QAPP Information Reference(s):
 
 
DECISION ID
92807
Region 5     
Rock Creek (Nevada County)
 
Pollutant: Oxygen, Dissolved
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Zero of the 51 samples exceed the Criteria/Objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Zero of 51 samples exceeded the Criteria/Objective and this does not exceed 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 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.
 
 
Line of Evidence (LOE) for Decision ID 92807, Oxygen, Dissolved
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 59359
 
Pollutant: Oxygen, Dissolved
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 51
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of the 51 daily averaged samples exceeded the water quality objective for dissolved oxygen in this water body.
Data Reference: Data for Various Pollutants at Placer County Utilities, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: From the Basin Plan, the minimum level for dissolved oxygen is 7 mg/L for waters designated as COLD.
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 collected at sites 22 - Lwr Rock Ck and 34 - Uppr Rock Ck.
Temporal Representation: Samples collected between 11/13/2001 and 7/10/2010.
Environmental Conditions:
QAPP Information: CITIZEN WATER MONITORING QUALITY ASSURANCE PROJECT PLAN FOR THE YUBA WATERSHED MONITORING COMMITTEE (June 30, 2008)
QAPP Information Reference(s):
 
 
DECISION ID
92808
Region 5     
Rock Creek (Nevada County)
 
Pollutant: Specific Conductivity
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of

Two lines of evidence are available in the administrative record to assess this pollutant. Zero of the 59 samples exceed the Criteria/Objective.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Zero of 59 samples exceeded the Criteria/Objective and this does not exceed 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 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.
 
 
Line of Evidence (LOE) for Decision ID 92808, Specific Conductivity
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 69432
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: SWAMP data indicates that 0 of 6 sample results exceed the criterion for electrical conductivity.
Data Reference: RWB5 Safe to Swim FY0708 FY0809
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The California Secondary Maximum Contaminant Levels for electrical conductivity provide a range of values including a recommended level (900 uS/cm), an upper level (1,600 uS/cm) and a short-term level (2,200 uS/cm). The recommended level of 900 uS/cm was used as it is protective of all drinking water uses.
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: Data for this line of evidence was collected at two monitoring sites [ Rock Creek Below Lake Vera - 516NEV905, Rock Creek Above Lake Vera - 516NEV904]
Temporal Representation: Data was collected over the time period 8/27/2008-9/3/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The SWAMP QAMP (2002) was used for data before Septemper 1, 2008 and SWAMP QAPP (2008) was thereafter.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 92808, Specific Conductivity
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 59358
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 53
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of the 53 daily averaged samples exceeded the water quality objective for electrical conductivity in this water body.
Data Reference: Data for Various Pollutants at Placer County Utilities, 2005-2010.
 
SWAMP Data: Non-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: Secondary Maximum Contaminant Levels and Compliance. CCR Title 22 section 64449.
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples collected at sites 22 - Lwr Rock Ck and 34 - Uppr Rock Ck.
Temporal Representation: Samples collected between 11/3/2001 and 7/10/2010.
Environmental Conditions:
QAPP Information: CITIZEN WATER MONITORING QUALITY ASSURANCE PROJECT PLAN FOR THE YUBA WATERSHED MONITORING COMMITTEE (June 30, 2008)
QAPP Information Reference(s):
 
 
DECISION ID
92809
Region 5     
Rock Creek (Nevada County)
 
Pollutant: Temperature, water
Final Listing Decision: Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status Original
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

One line of evidence is available in the administrative record to assess this pollutant. Three of the 97 samples exceed the Evaluation Guideline.

Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. Three of 97 samples exceeded the Evaluation Guideline and this does not exceed 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 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.
 
 
Line of Evidence (LOE) for Decision ID 92809, Temperature, water
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 69451
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 3
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: SWAMP data indicates that 3 of 6 sample results exceed the evaluation guideline value for Water Temperature.
Data Reference: RWB5 Safe to Swim FY0708 FY0809
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
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: Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: Inland Fishes of California (1976)
 
Spatial Representation: Data for this line of evidence was collected at two monitoring sites [ Rock Creek Below Lake Vera - 516NEV905, Rock Creek Above Lake Vera - 516NEV904]
Temporal Representation: Data was collected over the time period 8/27/2008-9/3/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The SWAMP QAMP (2002) was used for data before Septemper 1, 2008 and SWAMP QAPP (2008) was thereafter.
QAPP Information Reference(s): Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 92809, Temperature, water
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 69452
 
Pollutant: Temperature, water
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 91
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: None of the 91 samples exceeded the evaluation guideline for temperature in this water body (SYRCL, 2010).
Data Reference: Data in Yuba: metal, 2000-2007 and conventional, 2000-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. In determining compliance with the water quality objectives for temperature, appropriate averaging periods may be applied provided that beneficial uses will be fully protected (Central Valley Regional Board Basin Plan, Pg. III-8.00, Water Quality Objectives).
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: The lethal temperature threshold for Steelhead adult migration and holding and juvenile growth and rearing is 24 degrees Celsius. (Carter, 2008).
Guideline Reference: Effects of Temperature, Dissolved Oxygen/Total Dissolved Gas, Ammonia, and pH on Salmonids. Implications for California's North Coast TMDLs. California Regional Water Quality Control Board, North Coast Region
 
Spatial Representation: Samples were collected at the following locations: SYRCL monitoring station 22, Lwr Rock Ck SYRCL monitoring station 34, Uppr Rock Ck
Temporal Representation: Samples were collected monthly from 11/3/2001 to 7/10/2010.
Environmental Conditions:
QAPP Information: CITIZEN WATER MONITORING QUALITY ASSURANCE PROJECT PLAN FOR THE YUBA WATERSHED MONITORING COMMITTEE (June 30, 2008)
QAPP Information Reference(s):
 
 
DECISION ID
93149
Region 5     
Rock Creek (Nevada County)
 
Pollutant: pH
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)(2016)
Revision Status Original
Sources: A Source Unknown
Expected TMDL Completion Date: 2027
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.

Three lines of evidence are available in the administrative record to assess this pollutant. 30 of the 60 samples exceed the COLD, zero of the six samples exceed each of the MUN and REC water Criteria/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 CWA section 303(d) List.

This conclusion is based on the staff findings that:
1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
3. 30 of the 60 samples exceed the COLD water Criteria/Objective, 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.
 
 
Line of Evidence (LOE) for Decision ID 93149, pH
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 59360
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 54
Number of Exceedances: 30
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: Thirty of the 54 daily averaged samples exceeded the water quality objective for pH in this water body (they were below 6.5).
Data Reference: Data for Various Pollutants at Placer County Utilities, 2005-2010.
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: From the Basin Plan, pH levels should not be lower than 6.5 or higher than 8.5.
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 collected at sites 22 - Lwr Rock Ck and 34 - Uppr Rock Ck.
Temporal Representation: Samples collected between 11/13/2001 and 7/10/2010.
Environmental Conditions:
QAPP Information: CITIZEN WATER MONITORING QUALITY ASSURANCE PROJECT PLAN FOR THE YUBA WATERSHED MONITORING COMMITTEE (June 30, 2008)
QAPP Information Reference(s):
 
Line of Evidence (LOE) for Decision ID 93149, pH
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 69445
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: SWAMP data indicates that 0 of 6 sample results exceed the criterion for pH.
Data Reference: RWB5 Safe to Swim FY0708 FY0809
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
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: Data for this line of evidence was collected at two monitoring sites [ Rock Creek Below Lake Vera - 516NEV905, Rock Creek Above Lake Vera - 516NEV904]
Temporal Representation: Data was collected over the time period 8/27/2008-9/3/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 93149, pH
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 69444
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: SWAMP data indicates that 0 of 6 sample results exceed the criterion for pH.
Data Reference: RWB5 Safe to Swim FY0708 FY0809
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
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: Data for this line of evidence was collected at two monitoring sites [ Rock Creek Below Lake Vera - 516NEV905, Rock Creek Above Lake Vera - 516NEV904]
Temporal Representation: Data was collected over the time period 8/27/2008-9/3/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan
 
Line of Evidence (LOE) for Decision ID 93149, pH
Region 5     
Rock Creek (Nevada County)
 
LOE ID: 69443
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 6
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: SWAMP data indicates that 0 of 6 sample results exceed the criterion for pH.
Data Reference: RWB5 Safe to Swim FY0708 FY0809
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: pH should not be lower than 6.5 or higher than 8.5. (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin)
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: Data for this line of evidence was collected at two monitoring sites [ Rock Creek Below Lake Vera - 516NEV905, Rock Creek Above Lake Vera - 516NEV904]
Temporal Representation: Data was collected over the time period 8/27/2008-9/3/2008.
Environmental Conditions: Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: The SWAMP QAPP (2008) was followed.
QAPP Information Reference(s): Surface Water Ambient Monitoring Program Quality Assurance Program Plan