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Kennedy/Jenks/Chilton When the excavations were completed, four confirmation soil samples ' (C-1, C-2, C-3, and C-4) were collected. Each confirmation sample was comprised of surface soil collected from three points within each area excavated. Figure 9 shows the approximate sampling locations Confir- mation samples were collected by packing soil from each sampling location into a brass liner using disposable plastic scoops After sample collection, the ends of the brass liners were covered with Teflon sheets and clean plastic end caps. The caps were secured with duct tape to prevent slippage during shipping. A completed label was attached to each liner with the following information- site name, collection date/time, sample number, sample depth, and collector's initials. ' Samples were temporarily stored and transported in a chilled ice-chest under Chain-of Custody to the Kennedy/Jenks/Chilton Laboratory Division in San Francisco, Lzlifornia. ' Confirmation Sample Results Soil samples collected from the excavation areas were analyzed for ' organochlorine pesticides by EPA Method 8080. The concentrations of the pesticides which were detected are provided in Table 5. Laboratory reports are provided in Appendix A, Part 3 The range of concentrations of the organochlorine pesticides that were detected are listed below. tRange of Concentrations Compound Detected (ug/Kg) Alpha-BHC <6.25 to 200 Gamma-BHC <6 25 to 34 to <62.5 ' Beta BHC <6 25 to 34 to <62.5 Delta-BHC <6 25 to 15 to <62 5 Endrin <6.25 to 77.0 4,4'-DDE 66 to 1,400 4,4'-DDD 160 to 1,500 4,4'-DDT 130 to 1,700 Methoxychlor <6 25 to 560 The high concentration of pesticides in the extract from some of the samples required dilution of the extract as per EPA laboratory protocol . This resulted in higher detection limits for the other compounds analyzed in the extract. Laboratory analyses results indicate that one of the four confirmation samples (C-4) contained 4,4'-DDT at a concentration greater than 1,000 ug/Kg (1,700 ug/Kg) . Rather than continue excavation of soils, calculations were performed to confirm that the health-risk posed by ' soil remaining at the site was within the EPA's acceptable range. Risk calculations were made using the results of the confirmation pesticide analyses conducted on the soil remaining at the site following excavation The calculations indicated that soil remaining at the site does not pose an unacceptable health risk. Therefore, excavation of soil was completed and the four excavations were backfilled. A discussion of the human health assessment is provided in Appendix B. ' WPI13 3 2 882526.01