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DECISION ID |
4341 |
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| Pollutant: |
Silver (sediment) |
| Final Listing Decision: |
Delist from 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: |
Do Not Delist from 303(d) list (TMDL required list)(2006) |
| Revision Status |
Revised |
| Reason for Delisting: |
Flaws in original listing |
| Impairment from Pollutant or Pollution: |
Pollutant |
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| Weight of Evidence: |
This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section 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.
Ballona Creek, above Centinela Blvd., is a concrete-lined channel and the Ballona Creek Estuary, below Centinela Blvd., is soft-bottom. Data used in the 1996 WQA to assess Ballona Creek for silver in sediment appear to have been collected from the soft-bottom estuary. Data for silver in sediment from Line of Evidence (LOE) 2366 appears to follow the same the pattern and the information described LOE will not be considered in this decision. Accordingly, in the Ballona Creek Estuary Toxic Pollutants TMDL, "USEPA and the State found that the Ballona Creek listings for all sediments (cadmium, copper, lead and silver) were made in error and should be applied to the Estuary. |
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| RWQCB Board Decision / Staff Recommendation: |
After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because the original listing was faulty. |
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| SWRCB Board Decision / Staff Recommendation: |
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| USEPA Decision: |
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| LOE ID: |
28195 |
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| Pollutant: |
Silver |
| LOE Subgroup: |
Narrative Description Data |
| Matrix: |
Sediment |
| Fraction: |
None |
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| Beneficial Use: |
Warm Freshwater Habitat |
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| Number of Samples: |
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| Number of Exceedances: |
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| Data and Information Type: |
Not Specified |
| Data Used to Assess Water Quality: |
In the Basin Plan, the transition between Creek and Estuary is at Centinela Blvd. The Ballona Creek Estuary Toxic Pollutants TMDL indicates that, "Ballona Creek (above Centinela) is concrete-lined. Ballona Creek Estuary (below Centinela) is soft-bottomed. Agencies unfamiliar with this regulatory distinction may have inadvertently attributed samples collected from Ballona Creek Estuary to Ballona Creek. Sediment data used in the 1996 WQA appear to have been collected from soft-bottomed Estuary sediments as opposed to the concrete-lined channel." |
| Data Reference: |
Water Quality Control Plan Los Angeles Region R4 Basin Plan |
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Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009 |
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Ballona Creek Estuary Toxic Pollutants TMDL Final Staff Report. Prepared by California Regional Water Quality Control Board Los Angeles Region and U.S. Environmental Protection Agency Region 9. |
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| Water Quality Objective/Criterion: |
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| Objective/Criterion Reference: |
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| Evaluation Guideline: |
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| Guideline Reference: |
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| Spatial Representation: |
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| Temporal Representation: |
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| Environmental Conditions: |
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| QAPP Information: |
QA info not available. |
| QAPP Information Reference(s): |
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| LOE ID: |
2366 |
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| Pollutant: |
Silver |
| LOE Subgroup: |
Pollutant-Sediment |
| Matrix: |
Sediment |
| Fraction: |
Total |
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| Beneficial Use: |
Warm Freshwater Habitat |
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| Number of Samples: |
21 |
| Number of Exceedances: |
3 |
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| Data and Information Type: |
Chemical monitoring of sediments |
| Data Used to Assess Water Quality: |
There were 21 samples collected with 3 exceeding the PEL. Samples were collected by the Army Corps of Engineers (Heal the Bay, 2006). |
| Data Reference: |
Placeholder reference 2006 303(d) |
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| Water Quality Objective/Criterion: |
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| Objective/Criterion Reference: |
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| Evaluation Guideline: |
Probable Effects Level (PEL) of 1.77 ug/g (dry weight) (MacDonald et al., 1996). |
| Guideline Reference: |
Placeholder reference 2006 303(d) |
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| Spatial Representation: |
Several sites in the water body. |
| Temporal Representation: |
October 5-6, 1999. |
| Environmental Conditions: |
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| QAPP Information: |
ACOE Sediment Chemistry Data. |
| QAPP Information Reference(s): |