# Draft 2008 California 303(d)/305(b) Integrated Report

# Supporting Information

## Regional Board 3 - Central Coast Region

Water Body Name: | Hernandez Reservoir
Water Body ID: | CAL3055001619980828154910
Water Body Type: | Lake & Reservoir

DECISION ID | 6184
Pollutant: | Mercury
Final Listing Decision: | Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (being addressed by USEPA approved TMDL)(2006)
Revision Status | Revised
Sources: | Subsurface Mining
TMDL Name: | Clear Creek and Hernandez Reservoir Mercury
TMDL Project Code: | 123
Date TMDL Approved by USEPA: | 06/03/2004
Impairment from Pollutant or Pollution: | Pollutant
Weight of Evidence: | This pollutant is being considered for listing under section 2.2 of the Listing Policy. Under section 2.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. 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. Three out of 4 samples exceeded the OEHHA Screening Value. However, a TMDL is in place to address this pollutant in this water body. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. The USEPA final decision on the 2006 303(d) list was to move this listing to the 'being addressed by a USEPA approved TMDL' portion of the 303(d) list, because a TMDL and implementation plan has been approved for this water segment-pollutant combination by USEPA on 06/03/2004 (USEPA, 2007).
RWQCB Board Decision / Staff Recommendation: | No new data were assessed for 2008. The Regional Board will update this decision when new data and information become available and are assessed.
SWRCB Board Decision / Staff Recommendation: | N/A
USEPA Decision: | The USEPA final decision on the 2006 303(d) list was to move this listing to the 'being addressed by a USEPA approved TMDL' portion of the 303(d) list, because a TMDL and implementation plan has been approved for this water segment-pollutant combination by USEPA on 06/03/2004 (USEPA, 2007).

Lines of Evidence (LOEs) for Decision ID 6184

LOE ID: | 696
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Total
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 4
Number of Exceedances: | 3
Data and Information Type: | Fish tissue analysis
Data Used to Assess Water Quality: | Three out of 4 samples exceeded. Four filet composite samples were collected: 2 largemouth bass, 1 channel catfish, and 1 bullhead. Bass were collected in 1995 and 2002, channel catfish in 1995, and bullhead in 2002. Only the bullhead sample did not exceed the guideline (TSMP, 2002).
Data Reference: | Placeholder reference 2006 303(d)
Water Quality Objective/Criterion: | Central Coast RWQCB Basin Plan: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or produce detrimental physiological responses in human, plant, animal, or aquatic life.
Objective/Criterion Reference: | Placeholder reference 2006 303(d)
Evaluation Guideline: | 0.3 ug/g (OEHHA Screening Value).
Guideline Reference: | Placeholder reference 2006 303(d)
Spatial Representation: | One station located in Lake Hernandez on the San Benito River.
Temporal Representation: | Samples were collected 11/30/95 and 11/7/02.
Environmental Conditions: |
QAPP Information: | Toxic Substances Monitoring Program 1994-95 Data Report. Environmental Chemistry Quality Assurance and Data Report for the Toxic Substances Monitoring Program, 2001-2002. Department of Fish and Game
QAPP Information Reference(s):
LOE ID: | 695
Pollutant: | Mercury
LOE Subgroup: | Pollutant-Tissue
Matrix: | Tissue
Fraction: | Not Recorded
Beneficial Use: | Commercial or recreational collection of fish, shellfish, or organisms
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference 2006 303(d)
Water Quality Objective/Criterion: |
Objective/Criterion Reference:
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: |
Temporal Representation: |
Environmental Conditions: |
QAPP Information: | QA Info Missing
QAPP Information Reference(s):