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' 26 May 2004 . AGE-NC Project No 99-0637 ' Page 3 of 4 ' MTBE was detected in the ground water samples collected from wells MW1, MW4, MW5 and MW6 at concentrations ranging from 1 6 gg/l in well MW6 to 480 gg/l in well MW4 An iso-concentration map depicting the approximate distribution of dissolved MTBE is presented on ' Figure 4 No other analytes were detected at or above laboratory reporting limits in the ground water samples ' The analytical results of ground water samples are summarized in Tables 2 and 3 The laboratory report (MAI Work Order 0405269), QA/QC report and chain of custody form are included in Appendix B GeoTracker confirmation pages of the submitted laboratory electronic deliverable format (EDF) files are included in Appendix C I4.0. SUMMARY AND CONCLUSIONS The following conclusions were drawn from the results of this investigation • The ground water elevations ranged from 1192 feet to 12 54 feet above MSL Ground water flow was inferred to be flowing toward the northwest, away from the former UST area at an average gradient of 0 005 ft/ft • TPH-g, TPH-d, BTEX and fuel additives, with the exception of MTBE, were not detected in any of the ground water samples collected from the site • MTBE was detected in the ground water samples collected from wells MW I, MW4, MW5 and MW6 Concentrations of MTBE decreased to non detect limits this quarter in the samples collected from wells MW2,MW9 and MW 10 An iso-concentration map depicting the approximate distribution of dissolved MTBE is presented on Figure 4 • The lateral extent of MTBE-impacted ground water has been defined in all directions 5.0. RECOMMENDATIONS IBased on the findings of this investigation, AGE recommends • Continuation of the quarterly ground water monitoring program The next monitoring event was performed on 17 August 2004 • Initiation of a 24-week ozone sparging pilot test Ozone inl cction began on 19 August 2004 I Advanced GeoEnvironmental,Inc I