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I through MW-4 were single-completed utilizing 2-inch diameter PVC casing screened 30-50 feet bsg Analytical results detected TPH-g and BTEX constituents from the soil samples collected at B-1, B-2 and MW-1 through MW-4, the most intense petroleum hydrocarbon- impacted soil was encountered from B-2 at 35 feet at concentrations as high as 9,900 mg/kg TPH-g, 29 mg/kg benzene, 530 mg/kg toluene, 160 mg/kg ethylbenzene and 700 mg/kg ' xylene Initial water samples collected from MW-1 through MW-4 detected TPH-g at concentrations as high as 100,000 micrograms per liter (µg/1), BTEX constituents were detected at concentrations as high as 16,000 µg/1 xylenes Results of the July 1996 investigation were reported in Preliminary Investigation & Evaluation Report, dated 09 September 1996 • December 1996- Six soil probe borings (B-3 through B-8) were advanced both on-site and off-site and downgradient of the former UST area to maximum depths of 40 feet bsg Analytical results of soil samples detected TPH-g from B-3, B-4 and B-6 at concentrations I as high as 54 mg/kg, and BTEX constituents at concentrations as high as 2 1 mg/kg toluene Analytical results of grab water samples collected from B-3, B-4, B-6 and B-7 detected TPH-g at concentrations as high as 140,000 µg11 and BTEX constituents as high as 28,000 gg/l toluene, grab water samples were not collected from B-5 or B-8 Results of the December 1995 investigation were reported in Quarterly Report - July 1997, dated 11 August 1997 • June 1997-Five ground water monitoring wells (MW-5 through MW-9) and two soil vapor extraction wells(VW-1 and VW-2)were installed on and off-site to maximum depths of 45 feet bsg,wells MW-5 through MW-9 were single-completed utilizing 2-inch diameter PVC casing screened 25-45 feet bsg, wells VW-1 and VW-2 were single-completed utilizing 2- inch diameter PVC casing screened 15-35 feet bsg Analytical results of soil samples detected TPH-g from MW-6,VW-1 and VW-2 at concentrations as high as 6,600 mg/kg and BTEX constituents at concentrations as high as 580 mg/kg xylenes Analytical results of initial water samples detected TPH-g from MW-6, MW-8 and MW-9 at concentrations as high as 44,000 µg/1 and BTEX constituents as high as 5,800 µg/1 benzene Results of the December 1996 investigation were reported in Quarterly Report - July 1997, dated 11 August 1997 • July 1997 - An eight-hour soil vapor extraction (SVE) pilot test was performed to provide data to assess SVE as a component of the final remediation system A theoretical radius of influence of 30 feet was estimated during the pilot test at an induced vacuum of 0 1 inches of water Results of SVE pilot test were reported in Corrective Action Plan - May 1998, dated 05 May 1998 • October 1997 - Two air-sparge wells (AW-1 and AW-2) were installed at the site to maximum depths of 85 feet bsg, well AW-1 was dual-completed utilizing 2-inch diameter PVC casing screened 39-44 feet bsg and 50-60 feet bsg, well AW-2 was dual-completed utilizing 2-inch diameter PVC casing screened 40-45 feet bsg and 60-70 feet bsg Analytical results of soil samples detected TPH-g from AW-1 and AW-2 at concentrations as high as 1,500 mg/kg and BTEX constituents at concentrations as high as 160 mg/kg xylenes Analytical results of initial water samples detected 'IPH-g from AW-1 and AW-2 at concentrations as high as 63,000µg11 and BTEX constituents as high as 11,000 gg/l toluene APPENDIX A