See previous POLREP
EPA contractors have started to remove contaminated soils and shaping of the slope. A great deal more battery casings have been unearthed as originally anticipated.
The OSC has met with the property owner to discuss deed restrictions that will have to applied to certain parcels of land due to the lead contamination being left in place. Plan is to grade land to a 3 to 1 level. Prior to backfilling, EPA will document the levels of lead contamination that remain through the use of XRF instrumentation; 10% of these samples will be collected and shipped to a laboratory for analysis. Backfilling will consist of putting down orange construction fencing then geo-tech liner. The orange fencing will be used as a marker that will denote there is contamination under it.
ERRS have constructed roads along the site perimeter to allow access to the contaminated soil on Site. ERRS have excavated approximately 1,500 tons of battery debris and lead-contaminated soil. ERRS have constructed a poly-lined staging area for this contaminated soil, and secure the stockpile of soil daily with poly covering. ERRS have collected a composite soil sample from this stockpile to begin arrangements for T&D of the contaminated soil.
Following a heavy rain event, the water in Beaver Creek rose to high levels and had a high flow rate. START collected water samples from locations upstream, downstream, and adjacent to the contaminated soil to be analyzed for PCB congeners.
On December 10, 2009, START collected ten soil samples for XRF confirmatory analysis for lead. The samples were collected from excavated areas on Site, along with an elevated area of the Site where the soil is under consideration for backfilling use.
Interested parties may view added recent pictures in the Images section of the website: www.epaosc.org/twincities.
1. Remove contaminated sediment from Beaver Creek such that average concentrations along the entire length of the Site do not exceed 91.3 mg/kg lead and 1 mg/kg PCB;
2. Prepare Site for permanent erosions controls by grading and/or removal of soil and debris. Preparing the Site for surface for the permanent erosion controls may require removing or covering soil and debris with lead over 1,000 mg/kg and PCBs over 25 mg/kg such that soil at the surface contains lead less than 1000 mg/kg and PCBs less than 25 mg/kg:
3. Install permanent erosion controls that intend to protect the integrity of the response action and minimize the erosion of the installed cover;
5. Sample and consolidate or otherwise prepare the soils and sediments removed for appropriate off-Site disposal pursuant to Section 121(d)(3) of CERCLA and 40 CFR 300.440;
6. Dispose of off-Site all soils and sediments removed in accordance with Section 121(d)(3) of CERCLA and 40 CFR 300.440.
Continue excavation of designated areas.
Continue coordination with local and state officials.
1. Concentrations of lead in Site soils were determined up to 149,000 mg/kg.
2. Concentrations of lead in Site sediments were determined up to 677 mg/kg.
3. Concentrations of PCBs in Site soils were determined up to 66 mg/kg.
4. Concentrations of PCBs in Site sediments were determined up to 2 mg/kg.
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