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I29 June 2001 AGE-NC Project No 97-0343 Page 3 of 4 water samples collected from monitoring wells MW1,MW2 and MW3 at concentrations of 440µg/l, 1,100 µg/1 and 94 µg/l, respectively BTEX compounds were detected m the ground water samples collected from MW1,MW2 and MW3 at concentrations as high as 5 2 µg11 benzene, 150 µg/1 toluene, 56µg/1 ethylbenzene and 350 1,4g/1 total xylenes(MW2) TBA was detected for the first time in the ground water sample collected from MW2 at a concentration of 5 1 µg/l No other fuel oxygenated compounds were detected at or above laboratory reporting limits in the ground water samples lThe analytical results of water samples collected in May 2001 are summarized on Table 3 The laboratory reports (MAI Lab I D No 66926-66932), QA/QC report and chain-of-custody form are included in Appendix B 4.0. SUMMARY AND CONCLUSIONS Based on the data collected from the site, AGE finds • Ground water flow at the site on 07 May 2001 was inferred to be toward the west-northwest at an average gradient of 0 002 feet/feet Ground water elevations at the site increased an average of 1 07 feet since the first quarter 2001 monitoring events • Concentrations of dissolved TPH-g, TPH-d and BTEX compounds decreased in samples from wells MW1, MW2 and MW3 compared to the previous monitoring event TPH-g, TPH-d, and BTEX compounds were not detected at or above laboratory reporting limits an ground water samples collected from MW4 through MW7 TBA was detected for the first time in the ground water sample collected from MW2 at a concentration of 5 1 µg/l No other fuel oxygenated compounds were detected at or above laboratory reporting limits an the ground water samples The lateral extent of the fuel-impacted ground water appears to have been defined The current TPH-g, TPH-d and benzene asocontour maps are presented in Figures 4, 5 and 6 The vertical extent of impacted ground water has not been defined r 5.0. RECOMMENDATIONS ' Based on the findings of the environmental activities recounted an this report, AGE recommends I • Continued quarterly monitoring of the ground water monitoring wells on-sate The next monitoring event should be performed in August 2001 ' • Preparation of a work plan to define the vertical extent of impacted ground water Advanced GcoEnvironmental,Inc