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' 08 December 2004 AGE-NC Protect No 98-0511 ' Page 5 of 6 ' 4.0. SUMMARY AND CONCLUSIONS Based upon data collected from the site during the 21 May 2004 investigation, AGE concludes the ' following • Ground water elevations in the monitored area averaged 1 77 feet above MSL with the ' ground water elevation decreasing approximately 2 feet since the previous quarter The ground water flow direction was inferred to be generally west-southwest, consistent with previous flow directions, with a hydraulic gradient of 0 004 ft/ft to 0 006 ft/ft ' • TPH-g and BTEX compounds were detected in ground water sample MW-1 at concentrations of 32,000 µg/1 TPH-g, 200 µg/1 benzene, 130 µg/1 toluene, 530 µg/1 ' ethylbenzene, and 2,860 gg/l total xylenes, in addition, benzene and toluene were detected in sample MW-5 at concentrations of 24 µg/1 and 5 2 µg/l, respectively The detected concentrations of benzene and xylenes were above the MCLs for these contaminants in ' drinking water • MTBE was detected only in ground water sample MW-5 at a concentration of 38 µg/1 The I detected concentration of MTBE was above the MCL(13 µg/1)for MTBE in drinking water • Analytes of concern were not detected above laboratory reporting limits in ground water samples collected from wells MW-2 through MW-4 and MW-6 through MW-8 ' Hydrocarbon-impacted soil and ground water are not defined laterally along the up-gradient, eastern portion of the site This property is owned by the adjacent railroad and off-site access ' to the street east of the site has been unattainable ' 5.0. RECOMMENDATIONS IBased upon data collected from the site, AGE recommends • Continued quarterly ground water monitoring, and • Preparation of a Remedial Action Work Plan to propose appropriate remedial alternatives for minor soil contamination and the ground water contamination at the eastern edge of the site Consideration for the remediation method should include hydraulic controls of the water ' table to capture off-site contamination not readily accessible Advanced Geo Envi ron mental,Inc I