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

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name: Del Valle Reservoir
Water Body ID: CAL2043002420050519181540
Water Body Type: Lake & Reservoir
 
DECISION ID
5294
Region 2     
Del Valle Reservoir
 
Pollutant: Mercury
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: Source Unknown
Expected TMDL Completion Date: 2013
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. One line of evidence is available in the administrative record to assess this pollutant.

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. Four of the 12 samples exceeded the OEHHA Screening Value and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: No new data were assessed for 2008. 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.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 5294, Mercury
Region 2     
Del Valle Reservoir
 
LOE ID: 677
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 12
Number of Exceedances: 4
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Four out of 12 samples exceeded. A total of 12 composite samples were collected and analyzed from Del Valle Reservoir - 3 bluegill, 3 channel catfish, 3 largemouth bass, and 3 redear sunfish. One catfish and all three largemouth bass samples exceeded the Hg guideline (TSMP, 2002).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: San Francisco Bay RWQCB Basin Plan: Many pollutants can accumulate on particles, in sediment, or bioaccumulate in fish and other aquatic organisms. Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: OEHHA Screening Value of 0.3 ug/g for mercury (Brodberg and Pollock, 1999).
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: One station located in upper end of reservoir south of boat ramp.
Temporal Representation: All samples were collected on 4/25/2001.
Environmental Conditions:
QAPP Information: Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 2001-2002. Department of Fish and Game.
QAPP Information Reference(s):
 
 
DECISION ID
5356
Region 2     
Del Valle Reservoir
 
Pollutant: PCBs (Polychlorinated biphenyls)
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: Source Unknown
Expected TMDL Completion Date: 2019
Impairment from Pollutant or Pollution: Pollutant
 
Regional Board Conclusion: This pollutant is being considered for placement on the section 303(d) list under section 3.5 of the Listing Policy. One line of evidence is available in the administrative record to assess this pollutant.

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. Three of the 3 samples exceeded the OEHHA Screening Value and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy.
4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
 
Regional Board Decision Recommendation: No new data were assessed for 2008. 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.
 
USEPA Action (if applicable): USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.
 
 
Line of Evidence (LOE) for Decision ID 5356, PCBs (Polychlorinated biphenyls)
Region 2     
Del Valle Reservoir
 
LOE ID: 678
 
Pollutant: PCBs (Polychlorinated biphenyls)
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 3
Number of Exceedances: 3
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Three out of 3 samples exceeded. A total of 3 channel catfish composite samples were collected and analyzed from Del Valle Reservoir. All samples exceeded guideline (TSMP, 2002).
Data Reference: Placeholder reference 2006 303(d)
 
SWAMP Data: Non-SWAMP
 
Water Quality Objective/Criterion: San Francisco Bay RWQCB Basin Plan: Many pollutants can accumulate on particles, in sediment, or bioaccumulate in fish and other aquatic organisms. Controllable water quality factors shall not cause a detrimental increase in concentrations of toxic substances found in bottom sediments or aquatic life. Effects on aquatic organisms, wildlife, and human health will be considered.
Objective/Criterion Reference: Placeholder reference 2006 303(d)
 
Evaluation Guideline: 20.0 ng/g PCB - OEHHA Screening Value (Interim Health Advisory for Hg and PCB, Alameda County) (Brodberg and Pollock, 1999).
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: One station located in upper end of reservoir south of boat ramp.
Temporal Representation: All samples were collected on 4/25/2001.
Environmental Conditions:
QAPP Information: Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 2001-2002. Department of Fish and Game.
QAPP Information Reference(s):