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16 August 2044 <br /> w H <br /> . AGE-NC Project No 96-0235 <br /> L <br /> iPage 3 of 6 - <br />' 3.0. FINDINGS <br /> The hydrocarbon-impact to ground water was quantified by laboratory analysis of the ground water <br /> samples Ground water elevation and,gradient was determined by utilizing data collected from the <br />' field <br /> t i <br /> 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> Depths to ground water ranged from 16 92 feet to 19 88 feet below the tops of the well casings, <br />' ground water was within the screened intervals of the shallow wells,but was approximately 11 feet <br /> above the screened interval of intermediate wells MW-3 and EW-2 and between 20 1 and 47 2 feet <br /> above the screened intervals of the deep wells ~ <br /> f' u <br /> The elevation of ground water in each well was calculated by subtracting the depth to ground water <br /> from the surveyed casing elevations (Table 1) Ground water elevations at the site ranged from <br />' 11 83 feet(MW-8A)to 13 30 feet(MW-2)below mean sea level(MSL) The average ground water ' <br /> elevation at the site was approximately 12 22 feet below MSL The average ground water elevation <br /> in the wells increased by approximately 0 63 feet since the February 2004 ground water monitoring <br /> i event <br /> r <br /> Figure 3 and Figure 4 illustrate the ground water potentiometric surface based on the shallow- and <br />' deep-screened data sets Near the former UST cluster, the shallow-screened data delineate a radial <br /> ground water flow pattern,with a net flow towards the northeast at a gradient of 0 002 ft/ft,the deep- <br /> screened data delineated a ground water flow direction toward the northeast at a gradient of <br /> 0 403 fllfl Near the former,UST No 3 excavation ground water flow direction'at the shallow-' , <br /> screened data was inferred to be towards the southeast at a gradient of 0 005 fl/ft, ground water flow <br /> direction at the deep-screened level was inferred to be toward the southwest at a gradient of <br /> 0 013 ft/ft <br /> 3 2 ANALYTICAL RESULTS OF WATyER SAMPLES <br /> 3 <br />' TPH-g was detected m the samples collected from MW-1, MW-2, MW-9, MW-14B and EW-2 at <br /> concentrations ranging from 110 micrograms per liter(µg/1) in sample MW-14B to 27,000 µg/1 in <br /> sample MW-2 TPH-d was detected in samples collected from MW-1,,and MW-2 at concentrations <br /> of 1,500 µg/1 and 4,000 µg/1, respectively <br /> Various BTEX compounds were detectedrin samples MW-1, MW-2 and EW-2 at maximum <br />' concentrations of 2,400 µg/1 benzene(MW-1), 250 µg/1 toluene(MW-2), 1,100 µg/1 ethylbenzene <br /> • (MW-2) and 1,552 µg/1 xylenes (MW-2) <br /> I , <br /> Advanced GeoEnvironmental,Inc <br /> I r <br /> t <br />