| Water Body Name: | Squirrel Creek (Nevada County) |
| Water Body ID: | CAR5172002320080731223725 |
| Water Body Type: | River & Stream |
DECISION ID |
12035 |
Region 5 |
Squirrel Creek (Nevada County) |
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| Pollutant: | Mercury |
| Final Listing Decision: | Do Not List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.
One lines of evidence are available in the administrative record to assess this pollutant. One of the samples exceed the water quality 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 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 5 samples exceed the USEPA (CTR) mercury-based numeric criterion for human health 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: | 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. |
| USEPA Action (if applicable): | |
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| LOE ID: | 22438 | ||||
| Pollutant: | Mercury | ||||
| LOE Subgroup: | Pollutant-Water | ||||
| Matrix: | Water | ||||
| Fraction: | Total | ||||
| Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms | ||||
| Number of Samples: | 5 | ||||
| Number of Exceedances: | 1 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | A total of 9 water samples were collected at one location from this reach representing five 30-day average samples. One out of the five 30-day average samples exceeded the USEPA (CTR) mercury-based numeric criterion for human health. The total recoverable mercury concentrations in water ranged from 3.7 ng/l to 53.4 ng/l with an average of 25.8 ng/l for the five 30-day average samples. | ||||
| Data Reference: | Deer Creek Watershed Mercury Survey, draft 2-28-2007 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | The USEPA (CTR) numeric criterion for the protection of human health for the consumption of both water and fish that live in the water is 50 ng/l (30-day average) for total recoverable mercury (40 CFR 131.38). | ||||
| Objective/Criterion Reference: | Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency | ||||
| 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 one location from Squirrel Creek at the Pleasant Valley Road bridge crossing. | ||||
| Temporal Representation: | Water samples were collected during nine sampling events from 12/1/2005 to 6/29/2006. | ||||
| Environmental Conditions: | Samples represented a range of flow conditions, including two low-flow irrigation season events, four high-flow storms, and four intermediate-flow winter and spring events. | ||||
| QAPP Information: | Protocols for the water sampling conducted for this study are described in Field Sampling Protocols for Total Mercury Water Samples (Friends of Deer Creek, 2005). Quality Control for all of the elements described in section 6.1.4 of the Policy was conducted in accordance with the Citizen Water Monitoring Quality Assurance Project Plan For The Yuba Watershed Monitoring Committee (van der Veen, 2004). The Friends of Deer Creeks mercury survey was a collaboration with the Regional Water Quality Control Board/Central Valley Region and their CALFED mercury QA program. | ||||
| QAPP Information Reference(s): | |||||