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Parsons Engineering Science, Inc contained TPH-D at concentrations in excess of 1,000 mg/kg (SB2-30, 1,300 mg/kg, SB2-25, 2,900 mg/kg, B-1, 6,800 mg/kg, SB7-25, 9,600 mg/kg, and SB7-15, 16,000 mg/kg) Benzene was detected in 7 of the 86 samples collected The maximum concentration was 0 050 mg/kg Toluene was detected in 7 of the 90 samples The maximum concentration was 0 0034 mg/kg Ethylbenzene was detected in 11 of the 90 samples The maximum concentration was 0 760 mg/kg Total xylenes were detected in 28 of the 90 samples The maximum concentration was 3 10 mg/kg Figure 8 is a comprehensive soil analytical data map based on historic data collected between September 1991 and August 1996 The non-detect line for TPH-D surrounds the former USFT excavation area The TPH-D "zero-line" indicates the onsite lateral extent of TPH-D in soil with concentrations exceeding the laboratory practical quantitation limit The estimated area enclosed by the zero line is approximately 9,400 square feet In addition, the area enclosed by the 10 mg/kg line is estimated to be approximately 3,300 square feet and is contained entirely on Greyhound property Analytical results from boring SB-9 (converted to MW-4), located approximately 10 feet from the western edge of the property boundary, indicate that the western edge of the soil contamination is limited to the site property TPH- D and BTEX were not detected in any of the 10 samples collected from SB-9 The highest TPH-D concentrations have been detected above a depth of 30 feet bgs (Figures 6 and 7) The approximate volume of soil within the TPH-D zero line is 11,000 cubic yards The approximate volume of soil within the TPH-D 10 mg/kg line is 3,700 cubic yards Groundwater Contamination Assessment The type of contaminants detected include TPH-D and all four BTEX components TPH-G was not detected in the six groundwater samples that were analyzed for TPH-G Appendix I contains a summary of groundwater analytical data for the period September 1991 through August 1996 Over this period, wells MW-1, MW-2 and MW-3 were sampled 17 times TPH-D was detected in MW-1 on two occasions [August 1994 (80 µg/l) and December 1994 (50 µg/l)], in MW-2 on five occasions [June 1993 (70 µg/1), August 1994 (130 µg/1), December 1994 (50 pg/l), September 1995 (90 µg/1), and June 1996 (330 µg/l), and in MW-3 on seven occasions [June 1993 (50 µg/l), June 1994 (110 µg11), August 1994 (80 pall), December 1994 (70 pg/1), September 1995 (60 µg/l), December 1995 (70 µg/1), and June 1996 (1,200 µg/1)] TPH-D was not detected in any of the samples collected during the most recent groundwater sampling event (September 1996) Benzene was detected in MW-3 in June 1993 at a concentration of 0 7 µg/l Toluene was detected at a concentration of 0 5 pg,/1 in wells MWA (December 1992) and MW-3 (June 1993) Ethylbenzene and total xylenes were detected in well MW-3 in June 1993 at concentrations of 0 5 and 16 pall, respectively These compounds have never been detected PARESSYROI VOLIR IWP1727607 80969\27607R03 WW6 9