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

Supporting Information

Regional Board 5 - Central Valley Region

Water Body Name: Willow Creek (Sacramento County)
Water Body ID: CAR5142501120090107211344
Water Body Type: River & Stream
 
DECISION ID
73086
Region 5     
Willow Creek (Sacramento 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 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 only 1 sample is available and a minimum of 5 is needed for evaluation under section 3.2.

The data used satisfies the data quality requirements of section 6.1.4 of the Policy. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.
 
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 73086, Specific Conductivity
Region 5     
Willow Creek (Sacramento County)
 
LOE ID: 20282
 
Pollutant: Specific Conductivity
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Municipal & Domestic Supply
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: The sample collected by the Surface Water Ambient Monitoring Program did not exceed the "recommended" Secondary MCL of 900 uS/cm for electrical conductivity
Data Reference: SWAMP data entered by SWRCB into BDAT database
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: The secondary MCLs for electrical conductivity provide a range of values including a "recommended" level (900 uS/cm), upper level (1600 uS/cm) and a short-term level (2200 uS/cm). The ¿recommended¿ concentration was used as it is intended to be protective of all drinking water uses
Objective/Criterion Reference: California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: The sample was collected from Willow Ck at Folsom Boulevard
Temporal Representation: The sample was collected on September 27, 2006
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
74363
Region 5     
Willow Creek (Sacramento County)
 
Pollutant: pH
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: The decision has not changed. Region 5 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.

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 only 1 sample is available and a minimum of 5 is needed for evaluation under section 3.2.

The data used satisfies the data quality requirements of section 6.1.4 of the Policy. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: The decision has not changed. Region 5 data was not included in the 2012 Integrated Report so all decisions are carried over from the 2010 listing cycle.

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 it cannot be determined if 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 74363, pH
Region 5     
Willow Creek (Sacramento County)
 
LOE ID: 20289
 
Pollutant: pH
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Cold Freshwater Habitat
Aquatic Life Use: Cold Freshwater Habitat
 
Number of Samples: 1
Number of Exceedances: 0
 
Data and Information Type: PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: 0 of the 1 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
 
SWAMP Data: SWAMP
 
Water Quality Objective/Criterion: pH levels should not be lower than 6.5 or higher than 8.5 (Basin Plan Objective)
Objective/Criterion Reference: Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins. 4th ed
 
Evaluation Guideline:
Guideline Reference:
 
Spatial Representation: Samples were collected at Willow Ck @ Folsom Blvd.
Temporal Representation: The samples were collected from Sep 27 2006 to Sep 27 2006
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):