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I26 September 2002 AGE-NC Project No 98-0448 IPage 4of8 4.0. FINDINGS I AGE determined ground water flow direction and gradient from the field data collected on 30 May 2002, the contaminant impact to ground water was assessed from the laboratory data From field data collected at the SVE remediation system between 11 March and 11 June 2002,AGE determined the average TPH-g concentration and the average flow rate and calculated the approximate mass and volume of hydrocarbons removed 4 1 GROUND WATER ELEVATION AND GRADIENT The depths to ground water were measured between 17 69 and 20 22 feet below the tops of the well casings (Table 2) Ground water elevations at the site were calculated to be between 8 95 feet (MW-7) and 10 81 feet (MW-4B) below mean sea level (Table 2), the ground water elevation decreased an average 0 20 feet between the February 2002 and the May 2002 ground water monitoring events The ground water elevations are depicted in Figure 3 I • The general ground water gradient at the site was calculated to be approximately 0 01 ft/ft or less, or approximately 53 feet per mile, directed towards the south-southwest (Figure 3) I 4 2 LABORATORY RESULTS OF GROUND WATER SAMPLES TPH-g was detected in water samples collected from wells MW-1, MW-2, MW-4A, MW-4B and MW-6 at concentrations as high as 37,000 micrograms per liter (µg/l), the highest TPH-g concentration in first water was detected from MW-2 The laboratory reported that the sample chromatograms all contained significant unmodified or weakly modified gasoline The inferred extent of dissolved TPH-g is depicted in plan view in Figure 4 IVarious BTEX compounds were detected in water samples collected from MW-1,MW-2,MW-4A, MW-4B and MW-6 at concentrations as high as 5,800 yg/1 xylene(MW-2),the maximum benzene concentration was detected in the sample collected from MW-4B at a concentration of 2,800 yg/l MTBE was detected in water samples collected from MW-1, MW-4A, MW-4B and MW-8 at concentrations as high as 33,ug/l(MW-4B),DIPE was detected in a samples collected from MW-1, MW-4B and MW-8 at concentrations as high as 6 1,ug/1(MW-4B),TBA was detected on the sample collected from MW-4A at a concentration of 14,ugll No other fuel components were detected by laboratory analysis Previous and current analytical results of ground water monitoring well samples Advanced GeoEnvironmental,Inc