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08 October 1999 AGE-NC Project No 96-0229 ' Page 3 of 6 ' were measured between 24 87 and 26 60 feet below the tops of well casings,ground water elevations were calculated to be between 14 06 feet and 15 70 feet below mean sea level Ground water elevation at the site decreased an average 2 11 feet between the Apnl 1999 and the July 1999 ground ' water monitoring events The ground water elevation data for MW-1 through MW-10 during the January 1999 groundwater monitoring event is depicted in Figure 3 ' Ground water monitoring data collected in the area of wells MW-1 through MW-10 indicated that the ground water flow direction was generally toward the north at a gradient of 0 002 ft/ft, or ' approximately 11 feet per mile (Figure 3) Ground water was approximately 5 feet above the screened interval ;n monitoring well MW-4, ground water was approximately 22 to 24 feet above the screen intervals at MW-1 and MW I O-B Therefore these wells are"drowned", and yield samples ' more representative of deeper ground water conditions 32 LABORATORY RESULTS OF GROUND WATER SAMPLES A total of eleven ground water samples were submitted to a DHS-certified laboratory In July 1999 TPH-g was detected in water samples collected from wells MW-1, MW-2, MW-3 and MW-6 at concentrations ranging as high as 65,000 micrograms per liter(µg/1) BTEX compounds were detected in ground water samples collected from wells MW-1, MW-2, MW- 3, MW-6, MW-7 and MW-1 OB at concentrations ranging as high as 5,500 µg11 (xylenes, MW-1) The greatest benzene concentration was detected In the sample collected from well MW-1 (screened from 48 to 53 feet bsg) at a concentration of 4,800 µgll MTBE was detected in ground water samples collected from wells MW-1, MW-4, MW-7 and MW-8 at concentrations ranging as high Ias 370µg/l MTBE was confirmed utilizing EPA Method 8260 in samples collected from wells MW-1, MW-4, MW-6, MW-7 and MW-8 at concentrations ranging as high as 390 µg/l, DIPE was detected in the ground water sample collected from well MW-1 at a concentration of 11 µg11, TBA was detected in ground water samples collected from wells MW-4 at a concentration of 25 4g11 No other fuel Ioxygenated additives were detected above laboratory reporting limits from the analyzed samples Analytical results of the ground water samples are summarized in Table 2 The laboratory reports (Castle Analytical Laboratory Reference No 2402 and McCampbell Analytical Inc I D No 16628 through 16638) and chain=of-cu stody forms are presented in Appendix B A&anced GeoEmironmental,Inc I