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

Supporting Information

Regional Board 2 - San Francisco Bay Region

Water Body Name: Hill Slough
Water Body ID: CAR2072300020050602210728
Water Body Type: River & Stream
 
DECISION ID
5299
Region 2     
Hill Slough
 
Pollutant: Mercury
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)(2006)
Revision Status Original
Sources: Source Unknown
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 insufficient 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. One of 1 sample exceeded the OEHHA Screening Value and this does not exceed 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 Regional Board will update this decision when new data and information become available and are assessed.
 
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):
 
 
Line of Evidence (LOE) for Decision ID 5299, Mercury
Region 2     
Hill Slough
 
LOE ID: 1829
 
Pollutant: Mercury
LOE Subgroup: Pollutant-Tissue
Matrix: Tissue
Fraction: Total
 
Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms
 
Number of Samples: 1
Number of Exceedances: 1
 
Data and Information Type: Fish tissue analysis
Data Used to Assess Water Quality: Two samples were collected on the same day at the same location (hence they are considered one sample). Thus, 1 out of 1 sample exceeded. Two filet individual samples of striped bass were collected in 1997 (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 0.3 ug/g (Brodberg and Pollock, 1999).
Guideline Reference: Placeholder reference 2006 303(d)
 
Spatial Representation: One station located upstream of McCoy Ditch near Suisun City.
Temporal Representation: Samples were collected 2/27/97.
Environmental Conditions:
QAPP Information: Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program,1996 to 2000. Department of Fish and Game.
QAPP Information Reference(s):