| Water Body Name: | Casitas, Lake |
| Water Body ID: | CAL4022003220091208111831 |
| Water Body Type: | Lake & Reservoir |
DECISION ID |
17947 |
Region 4 |
Casitas, Lake |
||
| Pollutant: | Mercury |
| Final Listing Decision: | List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | New Decision |
| Revision Status | Revised |
| Sources: | Natural Sources | Source Unknown |
| Expected TMDL Completion Date: | 2021 |
| 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 line of evidence is available in the administrative record to assess this pollutant. Nine of 24 samples exceed the water quality objective. 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. Nine of 24 samples exceed the water quality objective 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: | N/A |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem. |
| USEPA Action (if applicable): | USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant. |
|
|||||
| LOE ID: | 31037 | ||||
| Pollutant: | Mercury | ||||
| LOE Subgroup: | Pollutant-Tissue | ||||
| Matrix: | Tissue | ||||
| Fraction: | Fish fillet | ||||
| Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms | ||||
| Number of Samples: | 24 | ||||
| Number of Exceedances: | 9 | ||||
| Data and Information Type: | Fish tissue analysis | ||||
| Data Used to Assess Water Quality: | Fish were collected for tissue analysis at two locations from Lake Casitas. A total of 24 sample composites were generated from two species: Largemouth Bass (22) and Common Carp (2). Details of the compositing protocol can be found in the March 2009 report entitled: "Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Study" (SWAMP, 2009). A total of 9 out of 24 samples exceeded the OHHEA fish tissue screening value for human health. | ||||
| Data Reference: | Data associated with report entitled: Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA | ||||
| Contaminants in Fish from California Lakes and Reservoirs: Technical Report on Year One of a Two-Year Screening Survey. A Report of the Surface Water Ambient Monitoring Program (SWAMP). California State Water Resources Control Board, Sacramento, CA | |||||
| Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008 | |||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | The Basin Plan contains the following objective: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Water Board. | ||||
| Objective/Criterion Reference: | Water Quality Control Plan Los Angeles Region R4 Basin Plan | ||||
| Evaluation Guideline: | Office of Environmental Health Hazard Assessment (OEHHA) Screening Value of 0.3 mg/kg to protect human health when consuming fish (OEHHA, 1999). | ||||
| Guideline Reference: | Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment | ||||
| Spatial Representation: | Samples were collected from two locations in Lake Casitas. As discussed in the Lakes and Reservoirs Report (SWAMP, 2009), individual sample locations consisted of an area within a given waterbody with an approximate one-mile diameter, from which multiple fish tissue samples were collected. The number of sample locations per waterbody was based on the overall size of the waterbody. Specifics of individual sampling locations can be found in the supplemental report entitled "Cruise Report for the Surface Waters Ambient Monitoring Program (SWAMP) Bioaccumulation Screening Study in California Lakes and Reservoirs, Sampling Dates: June 2007- March 2008" (SWAMP, 2008). | ||||
| Temporal Representation: | Samples were collected on June 13, 2007 | ||||
| Environmental Conditions: | There are no known environmental conditions (e.g., seasonality, land use practices, fire events, storms, etc.) that are related to these data. | ||||
| QAPP Information: | Samples were collected, processed, and analyzed in accordance with the methods described in "Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs." (SWAMP, 2008). | ||||
| QAPP Information Reference(s): | Quality Assurance Project Plan Screening Study of Bioaccumulation in California Lakes and Reservoirs. Moss Landing Marine Labs. Prepared for SWAMP BOG, 49 pages plus appendices and attachments | ||||