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' 06 July 1999 �• AGE-NC Project No. 95-0197 Page 5 of 8 AGE was able to determine general ground water flow direction and gradient from ground water ' monitoring data. Laboratory analysis of four ground water monitoring well samples detected total petroleum. hydrocarbons in one ground water sample; MTBE was detected in two ground water samples. 3.1 SOIL PROFILE ' Generally, a ale brown to mottled gray/brown,/brown very stiff to hard, fine sand silt was encountered p g Y � r3' Y between 5 feet bsg and 10 feet bsg. A brown, moist to saturated, medium dense to dense, silty fine ' sand was generally encountered between 10 feet bsg and 25 feet.bsg. A blue/gray to dark gray, saturated, medium dense to dense, poorly sorted, gravelly, silty, fine to coarse sand was generally ' encountered at depths between 25-and 35 feet bsg. Saturated soil was encountered at 20 feet bsg in borings MW-1 through MW-4; ground water levels ' were measured at 15 feet bsg utilizing a Solinst water level meter. Boring logs are included in Appendix A. General lithology beneath the site in cross-sectional view is depicted in Figures 3 and 4. 3.2. FIELD EVIDENCE OF HYDROCARBON-IMPACTED SOIL AND GROUND WATER ' Petroleum hydrocarbon odor or petroleum hydrocarbon vapor (using a PID) were not observed in soil sample duplicates collected from soil borings MW-1 through MW-4. Petroleum hydrocarbon odor was not detected in quarterly ground water samples collected from all ground water monitoring wells. ' 3.3. GROUND WATER ELEVATION AND GRADIENT On 12 April 1999, the depths to first encountered ground water in wells MW-1 through MW-4 ' ranged between 15.06 and 15.65 feet below the tops of well casings. Ground water elevations were calculated to lie between 10.27 feet and 10.41 feet below mean sea level; ground water elevations, as measured on 12 April 1999, are depicted in Figure 9. The general ground water gradient at the site ' was calculated to be approximately 0.002 ft/ft or approximately 11 feet per mile; the general ground water flow direction was calculated towards the northeast. In April 1999, the depths to first encountered ground water in wells MW-1 through MW-4 were approximately three to six feet below the tops of the well screens. Therefore, these wells are Advmutd GeoEnvironmeataL Inc.