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18 July 2005 <br /> S AGE-NC Project No 97-0326 <br /> Page 3 of 5 <br /> 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> At the time of the March 2005 sampling event, depths to ground water ranged from 35 07 feet to <br />' 36 81 feet below the tops of the well casings <br /> The elevation of ground water in each well was calculated by subtracting the depth to ground water <br />' from the casing elevations Ground water elevations ranged from 21 51 feet (MW-2) to 2198 feet <br /> (MW-9D) below mean sea level (MSL) <br />' First-encountered ground water was within the screen Interval of wells MW-1 through MW-3, <br /> MW-7, MW-8A and MW-9A, these wells should yield samples representative of shallow ground <br /> water conditions (Table 1), ground water from deep-screened wells MW-8[B-D] and MW-9[B-D] <br /> should yield samples representative of deeper ground water conditions <br /> A ground water elevation map of first-encountered ground water is presented in Figure 3 <br /> fFirst-encountered ground water was inferred to be flowing toward the south-southwest, hydraulic <br /> gradients ranged between 0 004 foot/foot(ft/ft)in the area between wells MW-1 through MW-3 and <br /> . 0 01 ftlft south of wells MW-1 and MW-3 The flow direction is generally consistent with previous <br /> rmonitoring events <br /> t32 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br />' Twelve ground water samples were collected and submitted for laboratory analysis for the <br /> constituents listed in Section 2 2 (Table 2) The analytical results for each hydrogeologic unit is <br /> characterized below <br /> HUI - TPH-g was detected in ground water samples collected in HU1 from wells MW-1, MW-2, <br /> MW-3,MW-8A,and MW-9A at concentrations ranging from 12,000 micrograms per liter(µgll)in <br />' sample MW-8A to 980,000 µg/1 in sample MW-3 (Figure 4) <br /> BTEX compounds were detected in all HU1 wells at maximum concentrations of 100,000 µg11 <br />' benzene (MW-3) and 90,000 µg/l ethylbenzene (MW-3), 200,000 pg/I toluene (MW-3) and <br /> 390,000 pg/l xylenes (MW-3) <br />' The fuel additive MTBE was detected in ground water samples collected from HU1 from wells MW- <br /> 1, MW-3, MW-8A, and MW-9A at concentrations ranging from 11 µg/I (MW-2) to 290 µg11 <br /> (MW-9A) (Figure 5) In addition, 1,2-DCA was detected in samples MW-1, MW-3, MW-8A, and <br /> MW-9A at a maximum concentration of 16 pg/1 (MW-3) <br /> Advanced GeoEnvironmental,Inc <br />