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I , 03 September 2002 AGE-NC Project No 99-0624 ' Page 3 of 5 were measured between 52 23 and,53 24 feet below the tops of the well casings, ground water ' elevations were calculated to be between 13 74 feet(MW-4)and 14 04 feet(MW-1)below mean sea level (MSL) Ground water elevation at the site decreased an average 192 feet between the March 2002 and the May 2002 ground water monitoring events (Table 2) The ground water elevation data ' for MW-1 through MW-4 during the May 2002 ground water monitoring event is depleted and contoured in Figure 3 ' The general ground water gradient in the area of wells MW-1 through MW-4 was calculated to be approximately 0 004 ft/ft or less, or approximately 21 feet per mile and inferred to be flowing towards the south-southwest I ' 32 LABORATORY RESULTS OF GROUND WATER SAMPLES A total of four ground water samples were submitted to a DHS-certified laboratory TPH-g was 1 detected in water samples collected from wells MW-2 and MW-3 at concentrations of 740 micrograms per liter (µg11) and 67 ug1l, respectively The laboratory indicated that the sample chromatograms from MW-2 and MW-3 had significant unmodified or weakly modified gasoline BTEX constituents were detected in ground water samples collected from wells MW-2 and MW-3 at concentrations ranging as high as 41 µg/1 (xylene, MW-2) IMTBE was detected(EPA 8260) in ground water samples collected from wells MW-1, MW-2 and MW-3 at concentrations ranging as high as 11,000 µg/l (MW-2) No other constituents of concern ' were detected above laboratory reporting limits in the analyzed samples Previous and current analytical results of ground water monitoring well samples are summarized in Tables 3 and 4 The laboratory reports (McCampbell Analytical Inc Lab I D No 0205441-1, 2 and 3) and chain-of- custody forms are presented in Appendix C ' 4.0. SUMMARY AND CONCLUSIONS ' The implications from the findings of the May 2002 investigation are • The average depth to ground water and ground water elevation on 30 May 2002 in I monitoring wells on-site was approximately 52%2 feet below surface grade and 14 feet below MSL, respectively • Ground water flow direction in the area of wells MW-1 through MW-4 was inferred to be Itowards the south-southwest at an approximate gradient of 0 004 ft/ft Due to the low • IAdvanced GcoEnvironmental,Inc