| Water Body Name: | Cosumnes River, Lower (in Delta Waterways, eastern portion) |
| Water Body ID: | CAR5440000020221118037022 |
| Water Body Type: | River & Stream |
DECISION ID |
152214 |
Region 5 |
Cosumnes River, Lower (in Delta Waterways, eastern portion) |
||
| Pollutant: | Mercury |
| Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2020) |
| Revision Status | Revised |
| Sources: | A Source Unknown |
| Expected TMDL Completion Date: | 2033 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This waterbody was split as part of the 2024 cycle Delta Remapping Project. Decisions were reassessed based on the new spatial representation. This pollutant is being considered for placement on the section 303(d) list under sections 3.1 and 3.5 of the Listing Policy. Under sections 3.1 and 3.5 a single line of evidence is necessary to assess listing status. One line of evidence are available in the administrative record to assess this pollutant. 15 of 16 tissue samples exceed the site specific objective for the for trophic level 4 fish for COMM beneficial uses. 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 CWA section 303(d) List. 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. 15 of 16 tissue samples exceeded the site specific objective for trophic level 4 fish for the COMM beneficial use 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: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded. |
| 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 not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded. |
|
|||||
| LOE ID: | 309339 | ||||
| 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: | 16 | ||||
| Number of Exceedances: | 15 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed SWAMP Sportfish Contamination in Lakes and Resrv data for Cosumnes River, Lower (below Michigan Bar; partly in Delta Waterways, eastern portion) to determine beneficial use support and the results are as follows: 15 of the 16 samples exceeded the objective for Mercury. This LOE contains data only for trophic level 4 fish and is based on samples of individual Largemouth Bass. | ||||
| Data Reference: | Statewide Lakes Sportfish Contamination Study 2007 2008 | ||||
| Contaminants in Fish from California Lakes and Reservoirs, 2007-2008: Summary Report on a Two-Year Screening Survey | |||||
| SWAMP Data: | SWAMP | ||||
| Water Quality Objective/Criterion: | For the Delta Waterways, the average methylmercury concentrations shall not exceed 0.08 and 0.24 mg methylmercury/kg, wet weight, in muscle tissue of trophic level 3 and 4 fish, respectively (150-500 mm total length). (Water Quality Control Plan, Central Valley Region, Sacramento River Basin and San Joaquin River Basin) | ||||
| Objective/Criterion Reference: | Water Quality Control Plan for the California Regional Water Quality Control Board Central Valley Region, Sacramento and San Joaquin River Basins; Fifth Edition. Revised May 2018 (with approved amendments) | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | Data was collected from 1 station(s) with the station code(s): 544TC0450. | ||||
| Temporal Representation: | Data for this line of evidence were collected on 2007-11-05. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program. | ||||
| QAPP Information Reference(s): | Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program | ||||