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I ' 16 January 2001 AGE-NC Project No 98-0505 ' Page 7 of 9 ' 43 GROUND WATER ELEVATION AND GRADIENT During the 07 October 1999 ground water monitoring event, the average ground water elevation of ' the five ground water monitoring wells was approximately 11 68 feet below mean sea level (ms]), with the average depth of ground water at 19 38 feet below casing grade During the October monitoring event, ground water was between 9 44 and 10 94 feet above the screened intervals in ' monitoring wells MW-1 through MW-5 Therefore, the five ground water monitoring wells were "drowned", and may not have yielded a sample fully representative of ground water conditions near the top of the saturated zone, where fuel hydrocarbons would be expected to have the greatest ' impact The average ground water elevation of the seven shallow ground water monitoring wells on 10 ' November 2000 was approximately 11 8 feet below msl, with the average depth ofwater at 19 5 feet below casing grade The ground water table occurred within the screened intervals of wells MW-7 and MW-8 During the November monitoring event, ground water was between 9 04 and 10 53 feet ' above the screened intervals in monitoring wells MW-1 through MW-5 The ground water table occurred approximately 40 feet above the screened interval of the deep well MW-6 IBased on data collected during the November 2000 groundwater monitoring event,the gradient was calculated to be 0 003 ft/ft (Figure 3) at the site Ground water flow direction was generally toward I the east Due to the low gradient at the site, slight variations in ground water measurements or changes of recharge/discharge of the local ground water could greatly modify ground water flow direction 4 4 ANALYTICAL RESULTS FROM GROUND WATER SAMPLES I Monitoring wells MW-1 through MW-8 were sampled on 10 October 2000 The analytical results of ground water samples are as follows I • Concentrations of TPH-g and BTEX were detected in ground water samples collected from each monitoring well sampled at the site (MW-1 through MW-8) TPH-g concentrations ranged from 95 micrograms per liter(µg/l) in MW-4 to 110,000 µg/1 in MW-1 Benzene was detected in the ground water sainples at concentrations ranging from 0 53 µg/1 (MW-8) to 9,400 µg/1 (MW-1) Toluene was detected at concentrations ranging from 3 2 gg/l (MW-8) to 25,000µg/1(MW-1) Ethylbenzene was detected at concentrations ranging from.0 59 µg/1 (MW-8) to 3,100 µg/1(MW-1) Total xylenes were detected at concentrations ranging from 3 6 µg/l (MW-1) to 14,000 gg/1(MW-8) • MTBE and other fuel oxygenates were not detected in the ground water samples collected Ifrom the site • 1,2-DCA was detected in groundwater samples collected from each well sampled at the site IAdvanced GeoEnvironniental Inc