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' 05 January 2006 AGE-NC Project No 97-0326 ' Page 3 of 5 ' 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION At the time of the December 2005 sampling event, depths to ground water ranged from 35 10 feet ' to 37 92 feet below the tops of the well casings First-encountered ground water was within the screened interval of wells MW-1 through MW-3,MW-7,MW-8A,and MW-9A,these wells should yield samples representative of shallow ground water conditions(Table 1) Ground water from deep- screened wells MW-8B-D and MW-9B-D should yield samples representative of deeper ground water conditions ' The elevation of ground water in each well was calculated by subtracting the depths to ground water from the casing elevations Ground water elevations ranged from 2166 feet(MW-9A)to 22 77 feet (MW-8D) below mean sea level (MSL) ' A ground water elevation map of first-encountered ground water is presented in Figure 3 First-encountered ground water was inferred to be flowing toward the south under a hydraulic ' gradient of approximately 0 004 foot/foot (ft/ft) The flow direction is generally consistent with previous monitoring events • 32 ANALYTICAL RESULTS OF GROUND WATER SAMPLES ' Twelve ground water samples were collected and submitted for laboratory analysis for the constituents listed in Section 2 2 (Table 2) The analytical results for each hydrogeologic unit are ' characterized below HU1 - TPH-g was detected in ground water samples collected in HU1 from wells MW-1, MW-2, ' MW-3, MW-8A, and MW-9A at concentrations ranging from 1,300 micrograms per liter(µg11) in sample MW-8A to 100,000 µg/1 in sample MW-3 (Figure 4) ' BTEX compounds were detected in ground water samples collected in HU1 from wells MW-1, MW-2, MW-3, MW-8A, and MW-9A at maximum concentrations of 26,000 dig/1 benzene, 16,000 µg/1 toluene, 6,000 µg11 ethylbenzene, and 37,000 µg/1 xylenes in sample MW-3 1 The fuel additives MTBE, TAME, and 1,2-DCA were detected in ground water samples collected in HUI from wells MW-1, MW-2, MW-3, MW-8A, and MW-9A at maximum concentrations of t 1,500 µg/l MTBE (MW-9A), 160 µg/l TAME (MW-2), and 97 µg11 1,2-DCA (MW-3), DIPE was detected in sample MW-1 at a concentration of 4 6 pg/l The areal distribution of MTBE within HU 1 is depicted on Figure 5 ' HU2 - TPH- and BTEX compounds were detected in samples MW-8B and MW-9B at maximum • g P ' Advanced GcoEnvironmental,Inc 1