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. 01 June 2003 AGE-NC Project No 98-0452 Page 3 of 4 MTBE was detected by EPA Method 8260B in the ground water samples collected from MW-2 and 1 MW-3 at concentrations of 52 micrograms per liter (µg11) and 75 gg/l, respectively No other fuel additives were detected at or above laboratory reporting limits ' Analytical results of ground water samples are summarized on Table 2 The laboratory report (CTEL Project No CT214-0303157) and chain-of-custody forms are included in Appendix C 4.0. SUMMARY AND CONCLUSIONS Based upon data collected from the site, AGE concludes the following ' • Average groundwater elevation at the site has remained relatively stable since gauging began in September 2000 • The ground water gradient was calculated to be 0 0023 feet/feet with a flow direction toward ' the west-southwest, which is more westerly than the flow direction determined during the fourth quarter 2002 Ground water flow direction during previous monitoring events has • alternated from the northeast to the southwest Local ground water appears to be influenced ' by seasonal hydrogeologic changes • TPH-g and BTE&X constituents were not detected at or above laboratory reporting limits ' in any of the ground water samples collected and analyzed since initiation of monitoring in November 1999 ' • MTBE was detected in monitoring wells MW-2 and MW-3 at concentrations of 52 µg/1 and 75 µg/l, respectively The concentrations detected in samples MW-2 and MW-3 exceed the DHS-Maximum Containment Level for MTBE in drinking water 1 5.0. RECOMMENDATIONS Based upon data collected from the site, AGE recommends • Continued ground water monitoring for MTBE The next quarterly monitoring event should be scheduled for June 2003 ' • AGE is currently preparing a work plan to collect additional soil and ground water samples to define the lateral extent of MTBE-impacted ground water west of MW-2 and north of MW-3 • ' Advanced GeoEnvironrnental,Inc