| Water Body Name: | Nicasio Reservoir |
| Water Body ID: | CAL2011301220050519182548 |
| Water Body Type: | Lake & Reservoir |
DECISION ID |
5315 |
Region 2 |
Nicasio Reservoir |
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| 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. Two of the 9 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. |
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| LOE ID: | 670 | ||||
| Pollutant: | Mercury | ||||
| LOE Subgroup: | Pollutant-Tissue | ||||
| Matrix: | Tissue | ||||
| Fraction: | Total | ||||
| Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms | ||||
| Number of Samples: | 9 | ||||
| Number of Exceedances: | 2 | ||||
| Data and Information Type: | Fish tissue analysis | ||||
| Data Used to Assess Water Quality: | Two out of 9 samples exceeded. A total of 9 composite samples were collected and analyzed from Nicasio Reservoir: 3 bluegill, 3 carp, and 3 largemouth bass. Two largemouth bass 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: | OEHHA Screening Value of 0.3 ug/g for mercury (Brodberg & Pollock, 1999). | ||||
| Guideline Reference: | Placeholder reference 2006 303(d) | ||||
| Spatial Representation: | One station. | ||||
| Temporal Representation: | All samples were collected on 9/19/2001. | ||||
| 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): | |||||