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) U 14 May 2004 AGE-NC Project No 96-0235 Page 4 of 5 Analytical results of water samples collected during the first quarter of 2004 are summarized on Tables 2 and 3, analytical results from previous monitoring events are summarized on Tables 4 and 5 Figures 5 and 6 illustrate the ground water contamination plumes in upper and lower ground water intervals, respectively The laboratory report (CTEL Laboratory IDs 0402-024-1 through 0402-024-19),chain-of-custody forms and the laboratory QA/QC report are included in Appendix C 4.0. SUMMARY AND CONCLUSIONS Based on the data collected from the former UST cluster area, AGE finds • The shallow-screened data delineate a radial ground water flow pattern, with a net flow towards the northeast at a gradient of 0 002 ft/ft, the deep-screened data delineated a ground water flow direction toward the east at a gradient of 0 009 ft/ft Ground water gradient and flow direction observed during the first quarter 2004 were similar to the previous quarter • TPH-g was detected in the ground water sample collected from MW-9 at a concentration of 140 µg/1 • MTBE was not detected in the shallow-screened wells sampled during the first quarter 2004 MTBE was detected by EPA Method 8260B In the deep-screened wells MW-9, MW-11B, MW-12B, MW-13B and MW-14B at concentrations as high as 140 µg/1 (MW-9) The reported MTBE concentrations were above the DHS' Primary MCL of 13 µg/1 in drinking water • 1,2-DCA was detected in the ground water sample collected from well MW-14B, the detected concentration exceeded the DHS' MCL • The most impacted ground water appears to be centered around the former UST dispenser location The vertical extent of the contamination plume,as well as the lateral extent east and south of the former UST cluster, are not well defined • Monitoring well MW-10 was damaged during the fourth quarter 2003 overexcavation activities and was not sampled Based on the data collected from the former UST No 3 area, AGE finds • The ground water flow direction at the shallow-screened level was inferred to be towards the southeast at a gradient of 0 005 ft/ft, ground water flow direction at the deep-screened level was inferred to be toward the south-southwest at a gradient of 0 013 ft/ft Ground water gradient and flow direction observed during the first quarter 2004 were similar to the previous quarter • TPH-g was detected in the samples collected from MW-1, MW-2 and EW-2 at Advanced GeoEnvironmental,Inc