| Water Body Name: | Lexington Reservoir |
| Water Body ID: | CAL2054002020000304130209 |
| Water Body Type: | Lake & Reservoir |
DECISION ID |
151591 |
Region 2 |
Lexington 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)(2018) |
| Revision Status | Revised |
| Sources: | A Source Unknown |
| Expected TMDL Completion Date: | 2037 |
| 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. Under section 3.5 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess the pollutant. LOE 92134 is replaced with LOE 307463. LOE 307463 is a reassessment of the same data following the statewide mercury objectives adopted in 2017. COMM beneficial use: Fish used in the COMM assessment are limited to lengths that are within Calif. Dept. of Fish and Wildlife legal size limits applicable to this waterbody. LOE 307463: 2 of 2 samples exceed the mercury objective and consist of 25 trophic level 4 fish (CDFW legal size limit). WILD beneficial use: LOE 307479: 2 of 2 samples exceed the mercury objective and consist of 25 trophic level 3 and 4 fish. LOE 307464: 2 of 2 samples exceed the mercury objective and consist of 25 trophic level 4 fish (CDFW legal size limit). 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. Tissue samples were compared to the prey fish objective and 2 of 2 samples exceed for WILD beneficial use. Samples may consist of a mix of trophic levels and are from a minimum of 2 annual averages and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. CDFW legal fish limit fish fillet tissue samples were compared with the sport fish objective and 2 of 2 samples exceed for WILD beneficial use and 2 of 2 samples exceed for the COMM beneficial use. The samples consist of trophic level 4 fish and are from a minimum of 2 annual averages and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 5. 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: | Decision written by SWRCB staff. |
| 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. |
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| LOE ID: | 307479 | ||||
| Pollutant: | Mercury | ||||
| LOE Subgroup: | Pollutant-Tissue | ||||
| Matrix: | Tissue | ||||
| Fraction: | Fish fillet | ||||
| Beneficial Use: | Wildlife Habitat | ||||
| Number of Samples: | 2 | ||||
| Number of Exceedances: | 2 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Guadalupe River Watershed Mercury TMDL project, Aug. 2004-Nov 2006 data for Lexington Reservoir to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the water quality threshold for Mercury. All fish collected within the same calendar year with a reported length of 50-150 mm were averaged into a single sample, independent of species or trophic level, for comparison with the objective. This LOE consists of a total of 25 fish, which were aggregated into 2 annual averages, consisting of 2 fish species (5 composite(s) of Pumpkinseed each composed of 1 fish per composite, 20 composite(s) of Largemouth Bass each composed of 1 fish per composite). Of these annual averages, 2 average(s), (Year(s): 2006, 2004) exceeded the objective. | ||||
| Data Reference: | Data from the Guadalupe River Watershed Mercury TMDL project, Aug. 2004-Nov 2006 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Water Quality Control Plan for the San Francisco Bay Basin: 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: | Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2) | ||||
| Evaluation Guideline: | The Statewide Prey Fish Water Quality Objective for the protection of Wildlife Habitat comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.05 mg/Kg wet weight whole fish samples of any fish species between 50 to 150 mm in total length collected between February 1 and July 31. (SWRCB Resolution No. 2017-0027) | ||||
| Guideline Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Spatial Representation: | Data were collected from 1 station(s). Station Code(s): LR-01, LR-02, LR-03, LR-04, LR-05, LR-06, LR-07, LR-08, LR-09, LR-10, LR-11, LR-21, LR-22, LR-23, LR-24, LR-25, LR-26, LR-27, LR-28, LR-29, LR-30, LR-31, LR-32, LR-33, LR-34, LR-35, LR-36, LR-37, LR-38, LR-39, LX1, LX10, LX11, LX12, LX2, LX3, LX4, LX46, LX47, LX48, LX5, LX6, LX7, LX8, LX9, LX13, LX14, LX15, LX49, LX50 (Lexington Reservoir). | ||||
| Temporal Representation: | Data for this line of evidence were collected between 2004-09-08 and 2006-11-14. When composited fish were collected over multiple days, the first day of fish collection was used as the sample date in the LOE, both for LOE writing, and for averaging period purposes. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Technical Memorandum 7.4.2, Quality Assurance Plan, Prepared for Santa Clara Valley Water District. June 13 | ||||
| QAPP Information Reference(s): | Technical Memorandum 7.4.2, Quality Assurance Plan, Prepared for Santa Clara Valley Water District. June 13 | ||||
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| LOE ID: | 307463 | ||||
| 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: | 2 | ||||
| Number of Exceedances: | 2 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Guadalupe River Watershed Mercury TMDL project, Aug. 2004-Nov 2006 data for Lexington Reservoir to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the water quality threshold for Mercury. This LOE contains data only for trophic level 4 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 25 fish were aggregated into 2 annual averages, which consisted of 1 fish species (25 composite(s) of Largemouth Bass each composed of 1 fish per composite). Of these annual averages, 2 average(s), (Year(s): 2004, 2006) exceeded the objective.This LOE does not contain data from fish who's average length was outside of the legal size limits as described by the California Department of Fish and Wildlife Fishing Regulations. | ||||
| Data Reference: | Data from the Guadalupe River Watershed Mercury TMDL project, Aug. 2004-Nov 2006 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Water Quality Control Plan for the San Francisco Bay Basin: 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: | Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2) | ||||
| Evaluation Guideline: | The Statewide Sport Fish Water Quality Objective for the protection of the Commercial and Sport Fishing beneficial comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027. | ||||
| Guideline Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Spatial Representation: | Data were collected from 1 station(s). Station Code(s): LR-01, LR-02, LR-03, LR-04, LR-05, LR-06, LR-07, LR-08, LR-09, LR-10, LR-11, LR-21, LR-22, LR-23, LR-24, LR-25, LR-26, LR-27, LR-28, LR-29, LR-30, LR-31, LR-32, LR-33, LR-34, LR-35, LR-36, LR-37, LR-38, LR-39, LX1, LX10, LX11, LX12, LX2, LX3, LX4, LX46, LX47, LX48, LX5, LX6, LX7, LX8, LX9, LX13, LX14, LX15, LX49, LX50 (Lexington Reservoir). | ||||
| Temporal Representation: | Data for this line of evidence were collected between 2004-09-08 and 2006-11-14. When composited fish were collected over multiple days, the first day of fish collection was used as the sample date in the LOE, both for LOE writing, and for averaging period purposes. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Technical Memorandum 7.4.2, Quality Assurance Plan, Prepared for Santa Clara Valley Water District. June 13 | ||||
| QAPP Information Reference(s): | Technical Memorandum 7.4.2, Quality Assurance Plan, Prepared for Santa Clara Valley Water District. June 13 | ||||
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| LOE ID: | 307464 | ||||
| Pollutant: | Mercury | ||||
| LOE Subgroup: | Pollutant-Tissue | ||||
| Matrix: | Tissue | ||||
| Fraction: | Fish fillet | ||||
| Beneficial Use: | Wildlife Habitat | ||||
| Number of Samples: | 2 | ||||
| Number of Exceedances: | 2 | ||||
| Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
| Data Used to Assess Water Quality: | Water Board staff assessed Guadalupe River Watershed Mercury TMDL project, Aug. 2004-Nov 2006 data for Lexington Reservoir to determine beneficial use support and the results are as follows: 2 of the 2 samples exceeded the water quality threshold for Mercury. This LOE contains data only for trophic level 4 fish. The concentration of Mercury in fish collected within the same calendar year, for the same trophic level were averaged into a single sample for comparison with the objective. A total of 25 fish were aggregated into 2 annual averages, which consisted of 1 fish species (25 composite(s) of Largemouth Bass each composed of 1 fish per composite). Of these annual averages, 2 average(s), (Year(s): 2006, 2004) exceeded the objective.This LOE does not contain data from fish who's average length was outside of the legal size limits as described by the California Department of Fish and Wildlife Fishing Regulations. | ||||
| Data Reference: | Data from the Guadalupe River Watershed Mercury TMDL project, Aug. 2004-Nov 2006 | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | Water Quality Control Plan for the San Francisco Bay Basin: 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: | Water Quality Control Plan (Basin Plan) San Francisco Bay Basin (Region 2) | ||||
| Evaluation Guideline: | The Statewide Sport Fish Water Quality Objective for the protection of Wildlife Habitat comes from the Statewide Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California, and is 0.2 mg/Kg wet weight skinless fillet samples of trophic level 3, or trophic level 4 fish (whichever is highest in the water body) over a one year averaging period. If trophic level 3 fish are used in the assessment then the Prey Fish Water Quality Objective must also be used to determine that the Sport Fish Objective is being met. Trophic levels of applicable fish are defined in, but not limited to those in Attachment C of the Final Regulatory Language document (Appendix A) of State Water Resources Control Board Resolution No. 2017-0027. | ||||
| Guideline Reference: | Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy | ||||
| Spatial Representation: | Data were collected from 1 station(s). Station Code(s): LR-01, LR-02, LR-03, LR-04, LR-05, LR-06, LR-07, LR-08, LR-09, LR-10, LR-11, LR-21, LR-22, LR-23, LR-24, LR-25, LR-26, LR-27, LR-28, LR-29, LR-30, LR-31, LR-32, LR-33, LR-34, LR-35, LR-36, LR-37, LR-38, LR-39, LX1, LX10, LX11, LX12, LX2, LX3, LX4, LX46, LX47, LX48, LX5, LX6, LX7, LX8, LX9, LX13, LX14, LX15, LX49, LX50 (Lexington Reservoir). | ||||
| Temporal Representation: | Data for this line of evidence were collected between 2004-09-08 and 2006-11-14. When composited fish were collected over multiple days, the first day of fish collection was used as the sample date in the LOE, both for LOE writing, and for averaging period purposes. | ||||
| Environmental Conditions: | |||||
| QAPP Information: | Technical Memorandum 7.4.2, Quality Assurance Plan, Prepared for Santa Clara Valley Water District. June 13 | ||||
| QAPP Information Reference(s): | Technical Memorandum 7.4.2, Quality Assurance Plan, Prepared for Santa Clara Valley Water District. June 13 | ||||