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1 pe 30 March 1999 AGE-NC Project No 96-0263 Page 5 of 7 BTEX compounds were detected in eleven of the fifteen soil samples analyzed The greatest ' concentrations of BTEX compounds detected were generally in soil samples collected at depths of five and ten feet bsg, however, in the former dispenser area BTEX compounds were detected in a soil sample collected from a depth of twelve feet bsg at a considerable concentration The ' concentrations detected dropped 2 orders of magnitude in a soil sample collected at 15 feet bsg in the same boring In the former dispenser area, the concentrations of BTEX compounds detected in ' the deepest sample collected (25 feet bsg) were above the method detection limits, yet were low compared to concentrations in soil samples collected at depths of 5 feet to 35 feet bsg MTBE was detected in 12 of the fifteen soil samples analyzed MTBE concentrations detected in soil from depths less than 10 feet bsg were as high as 43,000 kzg/kg (B5-10') MTBE was detected in the soil sample collected at 25 feet bsg at a concentration of 58 µg/kg Laboratory results of soil samples analyzed for petroleum hydrocarbons area summarized in Tables 2 and 3 The laboratory reports(MAI Laboratory ID 91060 to 91063, and 91065 to 910 75), QA/QC ' reports and chains-of-custody are included in Appendix B 4 3 HYDROCARBON-IMPACTED GROUND WATER TPH-g was detected in four of the seven grab ground water samples collected from the site at concentrations ranging from 3,200 to 27,000 micrograms per liter (ug/1) BTEX compounds were detected in four of the water samples at significant concentrations ranging from 30µg/1 benzene in boring B3 to 5,400 /.zg/l of xylene in boring B 1 MTBE was the only oxygenated fuel additive detected in the water samples, and was detected in five of the seven samples analyzed at concentrations ranging from 65 µg/l to 11,000,ug/1 Only the grab ground water samples collected from bonngs B7 and B9 did not contain detectable concentrations of MTBE Laboratory results of grab ground water samples analyzed for petroleum hydrocarbons and fuel additives are summarized in Tables 4 and 5 The laboratory reports (MAI Laboratory ID 91051 to 91059), QA/QC reports and chain-of-custody forms are Included in Appendix B Figure 4 depicts the areal distribution of detected analytes in grab ground water samples E5.0. SUMMARY AND CONCLUSIONS The following conclusions were drawn from the results of this investigation • Ground water at the site was encountered at a depth of approximately 10 feet bsg The Advanced GcoEnvironmental,Inc I