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1 <br />' 25 March 2004 <br /> i AGE-NC Protect No 97-0249 <br />' Page 6 of 7 <br />' of-custody forms are presented in Appendix C Analytical ground water data for the Flag City <br /> Chevron's monitoring events are Included in Appendix B <br />' 4.0. SUMMARY AND CONCLUSIONS <br />' The implications from the December 2003 ground water monitoring event are as follows <br /> Generally,depth to ground water at the site varied between 11 and 14 feet bsg,ground water <br />' elevations ranged between 3 85 feet(MW-6)and 4 32 feet(MW-10F)below mean sea level <br /> - Ground water in Hydrogeologic Unit 1 at the Three B's Truck Plaza site was inferred to be <br /> east and oriented towards a ground water depression in the area of Flag City Chevron wells <br /> MW-1, MW-2 and MW-4 (Figure 4) <br /> Ground water in Hydrogeologic Unit 2 at the Three B's Truck Plaza was inferred to be <br /> eastwardly and oriented towards a ground water depression in the area of Flag City Chevron <br /> well MW-6 (Figure 5) <br /> - Ground water in Hydrogeologic Units 3,4 and 6 at the Three B's Truck Plaza and Flag City <br />� . Chevron were Inferred to be towards the east (Figures 6, 7 and 8) <br /> C The most intense TPH-g impacted ground water was reported in the area of wells MW-2, <br /> MW-3 and MW-6 at concentrations as high as 12,000 µg/1 (Figure 9) <br /> o The most intense TPH-d impacted ground water was reported in the area of wells MW-3 and <br /> MW-6 at concentrations as high as 1,900 gg/l(Figure 10),an isolated TPH-d occurrence was <br /> Ireported at Flag City Chevron well MW-12A, approximately 200 feet southeast of the site <br /> The most intense on-site MTBE-impacted ground water was detected from Hydrogeologic <br /> Unit 1 in the In the area of Three B's Truck Plaza well MW-8A at a concentration of 99 µg/1 <br /> (Figure 11), from Hydrologic Unit 2 in the area of Flag City Chevron well MW-17 at a <br /> concentration of 45 µg/l(Figure 12), and from Hydrogeologic Unit 3 in the area of Flag City <br /> Chevron wells MW-11B and MW-18 at concentrations as high as 130 µg/l (Appendix A) <br /> The highest off-site concentrations of dissolved MTBE were detected in the Flag City <br /> Chevron samples collected from Hydrogeologic Unit 1 extraction wells EW-7 at 36 gg/1 <br /> (Figure 11) and from Hydrologic Unit 2 well MW-8A at 400 µg/l (Figure 12) <br /> Low concentrations of TBA and 1,2-DCA have been detected from wells MW-1, MW-2, <br /> MW-3,MW-5,MW-6,MW-8A,MW-10A and MW-11A suggesting that onlya minorTBA- <br /> impact and 1,2-DCA-impact to ground water in Hydrogeologic Unit 1 is present at the site <br /> - The lateral and vertical extent of the dissolved petroleum hydrocarbon plume is not known <br /> Itoward the northeast of Three B's Truck Plaza well MW-3, toward the south of Three B's <br /> Truck Plaza well MW-6 and toward the south of Flag City Chevron wells MW-16/17/18 <br /> I (Figures 9, 10, 11 and 12) <br /> Advanced GeoEnvironmental,Inc <br /> 1 <br />