See previous POLREP
ERRS continued excavation along the western slope of the Site. XRF screening data showed concentrations of lead in these excavated soils up to 31,074 ppm.
ERRS collected a composite soil sample for TCLP metals analysis from stockpile 2. ERRS shipped this sample to a laboratory for analysis, which will determine if stockpile 2 will have to be disposed of as "hazardous" waste.
ERRS began to stockpile fill material on Site, in preparation for construction of a cap over the remaining contaminated soils. ERRS are utilizing a large pile of fill material that was already present on the Site. ERRS collected a soil sample from this fill material to ensure that it could be used to construct the cap. ERRS analyzed the soil for metals, volatile and semi-volatile organics, and PCBs.
START continued to conduct air monitoring with DataRAM 4000's along the southern, western, and eastern areas of the Site. The maximum concentration of particulates that migrated from the Site during this operational period was 39.4 ug/m3.
Respiratory protection is still being utilized in the hot zone areas as an additional precaution, due to the presence of high lead concentrations in the excavation areas. START will continue to monitor the particulate levels in the hot zone; a determination to downgrade PPE may occur when the lead concentrations become lower in the Site soils. START utilized a personal DataRAM in the hot zone throughout the week; concentrations of particulates did not exceed 40 ug/m3.
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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