|
DECISION ID |
5126 |
|
Pollutant: |
Mercury (sediment) |
Final Listing Decision: |
List on 303(d) list (being addressed by USEPA approved TMDL) |
Last Listing Cycle's Final Listing Decision: |
Do Not Delist from 303(d) list (TMDL required list)(2006) |
Revision Status |
Revised |
Sources: |
Point Source | Urban Runoff/Storm Sewers |
TMDL Name: |
San Francisco Bay Mercury |
TMDL Project Code: |
6 |
Date TMDL Approved by USEPA: |
02/12/2008 |
Impairment from Pollutant or Pollution: |
Pollutant |
|
Weight of Evidence: |
A TMDL has been developed and approved by USEPA (02/12/2006) and an approved implementation plan is expected to result in attainment of the standard. This provides a sufficient justification in favor of placing this water segment-pollutant combination in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.
This pollutant is being considered for delisting under sections 4.6 of the Listing Policy. Under section 4.6 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. Based on section 4.6, it cannot be determined if the site has significant sediment toxicity or whether the pollutant is likely to cause or contribute to any toxic effect.
Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification in favor of removing this water segment-pollutant combination from the section 303(d) list in the Water Quality Limited Segments category.
This conclusion is based on the staff findings that:
1. The sediment quality guideline used complies, with the requirements of section 6.1.3 of the Policy.
2. The data used satisfies the data quality requirements of section 6.1.4 of the Policy.
3. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy.
4. None of 3 samples exceeded the 2.1 µg/g sediment quality guideline, 1 of 2 samples exhibit toxicity, and these do not meet the minimum data required for delisting as presented in Table 4.1 of the Listing Policy.
5. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. |
|
RWQCB Board Decision / Staff Recommendation: |
Water Board staff conclude that the water body should be placed in the Water Quality Limited Segments Being Addressed category of the section 303(d) list because a TMDL has been approved by USEPA and an approved implementation plan is in place. |
|
SWRCB Board Decision / Staff 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 it cannot be determined if applicable water quality standards are attained. |
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USEPA Decision: |
|
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|
|
LOE ID: |
52 |
|
Pollutant: |
Sediment Toxicity |
LOE Subgroup: |
Toxicity |
Matrix: |
Sediment |
Fraction: |
None |
|
Beneficial Use: |
Estuarine Habitat |
|
Number of Samples: |
2 |
Number of Exceedances: |
1 |
|
Data and Information Type: |
Toxicity testing of sediments |
Data Used to Assess Water Quality: |
Significant amphipod toxicity in 1 of 2 tests. Urchin toxicity in 1 of 2 samples (Hunt et al., 1998b). |
Data Reference: |
Placeholder reference 2006 303(d) |
|
Water Quality Objective/Criterion: |
All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. |
Objective/Criterion Reference: |
Placeholder reference 2006 303(d) |
|
Evaluation Guideline: |
BPTCP Reference envelope approach. |
Guideline Reference: |
Placeholder reference 2006 303(d) |
|
Spatial Representation: |
Data was synoptically collected with chemical measurements. |
Temporal Representation: |
Samples collected in December 1995 and April 1997. Temporal distribution of samples is described in the report: Sediment quality and biological effects of San Francisco Bay (Bay Protection and Toxic Cleanup Program), data August 1998. |
Environmental Conditions: |
|
QAPP Information: |
BPTCP Quality Assurance Project Plan. |
QAPP Information Reference(s): |
|
|
LOE ID: |
54 |
|
Pollutant: |
Mercury (sediment) |
LOE Subgroup: |
Pollutant-Sediment |
Matrix: |
Sediment |
Fraction: |
None |
|
Beneficial Use: |
Estuarine Habitat |
|
Number of Samples: |
3 |
Number of Exceedances: |
|
|
Data and Information Type: |
Chemical monitoring of sediments |
Data Used to Assess Water Quality: |
None of 3 samples exceed the sediment quality guideline. Previous BPTCP analyses used a guideline that was a factor of 3 lower than the guideline used in the current analysis (Hunt et al., 1998b). |
Data Reference: |
Placeholder reference 2006 303(d) |
|
Water Quality Objective/Criterion: |
All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce other detrimental responses in aquatic organisms.
There shall be no chronic toxicity in ambient waters. Chronic toxicity is a detrimental biological effect on growth rate, reproduction, fertilization success, larval development, population abundance, community composition, or any other relevant measure of the health of an organism, population, or community. |
Objective/Criterion Reference: |
Placeholder reference 2006 303(d) |
|
Evaluation Guideline: |
Sediment quality guideline of 2.1 ug/g used (PTI Environmental Services, 1991). |
Guideline Reference: |
Placeholder reference 2006 303(d) |
|
Spatial Representation: |
Data was synoptically collected with toxicity measurements. |
Temporal Representation: |
Samples collected in December 1995 and April 1997. Temporal distribution of samples is described in the report: Sediment quality and biological effects of San Francisco Bay (Bay Protection and Toxic Cleanup Program), data August 1998. |
Environmental Conditions: |
|
QAPP Information: |
BPTCP Quality Assurance Project Plan. |
QAPP Information Reference(s): |