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lie 29 June 2001 AGE-NC Project No 97-0333 ' Page 3 of 5 ' feet below the tops of well casings, ground water elevations were calculated to be between 16 23 feet and 16 36 feet above mean sea level Ground water elevation at the site decreased an average 0 40 feet between the January 2001 and the April 2001 ground water monitoring events The ground water ' elevation data for MW-1 through MW-5 during the April 2001 ground water monitoring event is depicted in Figure 3, well MW-6 was not utilized to contour ground water elevations because it has not been surveyed for elevation to grade Ground water flow direction for the area bound by wells ' MW-1 through MW-5 was inferred to be towards the northeast at a gradient of 0 001 Rift or less, or approximately 5 feet per mile(Figure 3) 3 2 LABORATORY RESULTS OF MONITORING WELL GROUND WATER SAMPLES ' A total of six ground water samples were submitted to a DHS-certified laboratory in April 2001 TPH-g was detected in water samples collected from wells MW-1, MW-2,MW-3,MW-4 and MW-6 at concentrations as high as 160,000 micrograms per liter(µg11), however the laboratory reported the sample chromatograms from MW-1 and MW-4 as having isolated peaks and samples MW-2, MW-3, MW-4 and MW-6 as having significant unmodified or weakly modified gasoline BTEX compounds were detected in the ground water samples collected from wells MW-2, MW-3, MW-4 and MW-6 at concentrations as high as 32,000 µg/1 (MW-6, toluene) The highest benzene concentration was detected in the water sample collected from well MW-2 at a concentration of 12,000 µg11 MTBE was detected at concentrations as high as 1,900,000 ug/l in water samples collected from MW-1, MW-2, MW-3 and MW-6 by the EPA 8020 analysis ' MTBE was detected in water samples collected from MW-1, MW-2, MW-3, MW-4 and MW-6 utilizing EPA Method 8260 Modified at concentrations as high as 2,000,000 µg/1 TAME was not ' detected in water samples collected from any wells during the April 2001 monitoring event, but TAME was previously detected in samples collected from MW-1 at concentrations as high as 1,100 Mcg/l No other fuel oxygenated compounds or volatile organic compounds (VOCs) were detected ' above the respected laboratory reporting limits, however chloroform was detected in water samples collected from MW-1 and MW-2 at concentrations as high as 28,000 µg/1 Previous and current analytical results of ground water monitoring well samples are summarized in Tables 2 and 3 The ' laboratory reports(McCampbell Analytical Inc 1 D No 66596 through 66601)and chain-of-custody forms are presented in Appendix B ' 40 SUMMARY AND CONCLUSIONS iThe implications from the April 2001 ground %tater :monitoring event are as follows Advanced Gco@ nrLronnfcnu1 Inc i