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07 September 2005 AGE-NC Project No 98-0540 Page 7 of 9 toluene, and 34 µg/1 xylenes The fuel additive 1,2-DCA was detected in the ground water samples from wells MW-1 and MW-3 through MW-5 at concentrations of 190 µg/1, 310 µg/l, 9 7 µg/1, and 9 5 µg/1, respectively No other target analytes were detected at or above laboratory reporting limits in the samples analyzed Analytical results of ground water samples are summarized in Table 4 Maps depicting the estimated lateral extents of dissolved TPH-g and 1,2-DCA are illustrated on Figures 6 and 7, respectively Copies of the laboratory report(CTEL Project No CT214-0506135), QA/QC reports, and chain of custody forms are included in Appendix H I3 5 GROUND WATER GRADIENT AND FLOW DIRECTION During the June 2005 ground water monitoring event, depths to ground water ranged between 78 58 feet (MW-2) and 8145 feet (MW-5) below the tops of the well casings By subtracting the depths to ground water from the surveyed relative casing elevations in monitoring wells MW-1 through MW-3, the average ground water elevation was calculated to be approximately 2197 feet below mean sea level (MSL), indicating an increase in ground water elevation of approximately 2 77 feet since the last ground water monitoring event in December 2004 (Table 1) Since a well- head elevation survey has not been completed for wells MW-4 and MW-5,these wells were not used to determine the average elevation At the time of the June 2005 ground water monitoring event, ground water was inferred to be flowing toward the southwest under a hydraulic gradient of approximately 0 007 foot/foot (ft/ft) During this monitoring event, ground water elevations were within the screened intervals of the I wells, indicating that the wells are properly screened to yield samples representative of shallow ground water conditions Figure 8 illustrates the contoured ground water elevation as measured on 14 June 2005 I ' 36 GEOTRACKER CONFIRMATIONS Documents confirming the upload of laboratory electronic deliverable format(EDF)files and depth to water measurements to GeoTracker are included in Appendix I I 4.0. SUMMARY AND CONCLUSIONS I Based upon the findings investigation, s of this AGE concludes • P g Advanced GeoEonronmental,Inc.