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1 . ' 25 April 2002 • AGE-NC Project No. 97-0343 ' Page 3 of 4 ' BTEX compounds were detected in the ground water samples collected from MW 1,MW2 and MW3 at concentrations as high as 93 µg/1 benzene, 3,300 gg/l toluene, 1,800 µg/1 ethylbenzene and 5,700 gg/l total xylenes (MW1). Fuel additives were not detected at or above laboratory reporting limits ' in the ground water samples. The analytical results of water samples collected in February 2002 are summarized on Table 2.The ' laboratory reports(MAI Lab I.D.Nos. 90287-90293), QA/QC report and chain-of-custody form are included in Appendix B. 4.0. SUMMARY AND CONCLUSIONS IBased on the data collected from the site, AGE finds: • Ground water flow at the site on 12 February 2002 was inferred to be generally toward the ' northwest at an average gradient of 0.003 feet/feet. Ground water elevations at the site increased in wells MW4 through MW7 an average of 3.45 feet since the fourth quarter 2001 monitoring event. e Concentrations of dissolved TPH-g, TPH-d and BTEX compounds increased in samples from wells MWI, 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 in ground water samples collected from MW4 through MW7.Fuel additives were not detected at or above laboratory reporting Iimits in 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 isocontour maps are presented in Figures 4, 5 and 6. 5.0. RECOMMENDATIONS Based on the findings of the environmental activities recounted in this report, AGE recommends g p continued quarterly monitoring of the ground water monitoring wells on-site. The next monitoring event should be performed in May 2002.In addition,AGE recommends the preparation of a Problem Assessment Report (PAR). Advanced GeoEnvironmental,Inc. I