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' 06 July 1999 (. AGE-NC Project No. 95-0197 Page 7 of 8 was between 15 feet bsg and 20 feet bsg. ' General lithology beneath the site is depicted in cross sectional view on Figures 3 and 4 and consists of pale brown to mottled gray/brown, very stiff.to hard, fine sandy silt between 5 feet bsg and 10 feet bsg;brown, moist to saturated, medium dense to dense, silty fine sand between 10 feet bsg and 25 feet bsg; blue/gray to dark gray, saturated, medium dense to dense, poorly sorted, gravelly, silty, fine to coarse sand between 25 and 35 feet bsg. ' Laboratory analysis of twelve soil samples did not detect any total petroleum hydrocarbons, volatile aromatics or fuel oxygenated compounds in any of the analyzed soil samples. The estimated extent of adsorbed petroleum hydrocarbons in soil is illustrated in cross sectional view in Figures 10 and 11 and in plan view on Figure 12. The estimated extent of petroleum hydrocarbon impacted soil extends horizontally approximately 25 feet southwest ' and northeast of the former fuel dispensing island area; and appears to extend vertically to at least 30 feet bsg. The vertical and horizontal extent of petroleum hydrocarbon-impacted soil is relatively unknown northwest and southeast of the former fuel dispenser island area. ' G The site gradient was calculated at 0.002 ft/ft, or approximately 11 feet per mile (Figure 9). Ground water was inferred to be flowing towards the northeast in the area bound by wells MW-1 through MW-4. The ground water depths in wells MW-1 through MW-4 were approximately three to six feet ' below the tops of the well screens. Therefore, these wells are "properly screened", and should yield samples representative of shallow ground water conditions. G TPH-d was detected in a ground water sample collected from well MW-1 at a concentration of 130 µg/l. ' C BTEX compounds were not detected in ground water samples collected from wells MW-1 through MW-4 Utilizing EPA Method 8020, MTBE was detected in the ground water sample collected from ' well MW-2 and MW-3 at concentrations ranging as high as 2.5 ,ug/l; utilizing EPA Method 8260, MTBE was confirmed in the ground water sample collected from well MW-2 at a concentration of 1.9 ,ugll.No other dissolved fuel-oxygenate analytes were detected above laboratory reporting limits. r - 5.0. RECOMMENDATIONS ' Based upon data collected during April 1999, AGE recommends: Advanced GeoEnvirnnmental, Inc.