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I24 October 2003 AGE-NC Protect No 97-0312 ' Page 3 of 4 ' 3 1 GROUND WATER ELEVATION AND GRADIENT Depths to ground water at the site ranged between 6127 to 62 03 feet below top of casing (btoc), rground water elevations were between 33 20 feet (UST-2) and 33 31 feet (UST-3, UST-5 and UST-6) below mean sea level (MSL) The average ground water elevation had increased by an average of 0 94 feet since the February 2003 monitoring event The ground water table occurred ' above the screened intervals of monitoring wells UST-2 through UST-4, the ground '%;�ater table occurred within the screened intervals of monitoring wells UST-5 and UST-6 Monitoring well UST- ' 7 was designed to monitor deeper ground water,with a 5-foot screened interval set at approximately 25 feet below the water table, since it possibly is monitoring a different hydraulic zone, UST-7 was not used to determine gradient and flow direction ' General ground water flow direction at the site was inferred to be west-northwest with an average gradient of approximately 0 0006 ft/ft or less Figure 3 depicts the ground water elevation contours ' for May 2003 Monitoring data from UST-2,UST-3 and UST-4 was combined with monitoring data collected from the adjacent Moore Truck Lines property to determine an approximate regional ground water flow direction 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES tDuring the May 2003 monitoring event,TPH-g,benzene and 1,2-DCA were detected in the sample collected from UST-5 at concentrations of 220 micrograms per liter (µg/1), 5 6 µg/1 and 300 µg/l, respectively TPH-d was detected in the sample collected from UST-3 at a concentration of 60 µg/1 MTBE and 1,2-DCA were detected in the sample collected from UST-6 at concentrations of 0 87 µg/1 and 4 S gg/l, respectively Tetrachloroethene was detected in the sample collected from UST-7 ' at a concentration of 0 99 µg/l No other target analytes were detected at or above laboratory reporting levels in the ground water samples collected this quarter The laboratory reports (MAI Lab IDs 0305262-001 through 0305262-007) and chain-of-custody forms are included in Appendix B Analytical results of water samples collected during the second quarter 2003 are summarized on Tables 2 and 3 The analytical ' results of all water samples are summarized on Tables 4 and 5 Figures 4,5 and 6 illustrate the areal extent of TPH-g/d-, benzene- and 1,2-DCA-impacted ground water, respectively 1 1 Advanced GeoEnviroamental,Inc