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I ' 13 July 2001 • AGE-NC Project No 96-0232 ' Page 13 of 15 ' • Decreasing ground water elevations were reported at the site between the March and June 2001 monitoring events, the decrease of ground water elevation is probably due to seasonal fluctuation Hydrographs depicting recorded ground water elevations at wells MW-2, ' MW-6A and MW-6B vs time are in Appendix I • The greatest concentration of on-site dissolved MTBE was detected in First Zone monitoring ' well MW-1 at a concentration of 15 µg/1 (Figure 7) and from First Zone extraction well EW-4 at a concentration of 140µg/l (Figure 8), low concentrations of on-site MTBE were detected in water samples from First Zone extraction wells EW-2, EW-5, EW-6, EW-8, ' EW-9 and EW-10 and Second Zone monitoring well MW-9A(Figure 9) • The greatest concentration of off-site MTBE was detected in Rocky's Upper Zone water near ' the Rocky's Restaurant domestic water well in MW-11B at a concentration of 190µg/l and in First Zone water from Three B's Truck Plaza well MW-4 at a concentration of 60 µg/1 (Figure 7), low concentrations of off-site MTBE were detected in First Zone water at wells ' MW-7, MW-12A, MW-13A, Three B's Truck Plaza wells MW-1, MW-2 and MW-6, and Second Zone water from well MW-11 A (Figure 8) • A First Zone water sample collected off-site from well MW-12A contained significant �. TPH-d, TPH-mo, toluene and xylene Low concentrations of dissolved TPH-d were also encountered in First Zone water from well MW-13A and Secondary Aquifer Zone water from well MW-8B ' S.O. CONCLUSIONS AGE interprets the results of all work completed to indicate a Flag City Chevron release of ' hydrocarbons and MTBE occurred in the areas of the fuel dispensers,UST pit and/or storm drain, migrated through the First Zone and upper Second Zone to the Rocky's Restaurant domestic well, at which point it apparently migrated vertically to the Rocky's Upper, Secondary Aquifer and ' Primary Aquifer Zones ' Between March and June 2001, substantial decreases of dissolved MTBE were detected in samples collected from RDW-1, from monitoring wells MW-1, MW-6B, MW-9A, MW-9C, MW-11A, MW-11B, MW-11D, from extraction wells EW-2, EW-4, EW-5, EW-6, EW-7, EW-8, EW-9, ' EW-10 and influent ground water pump and treat samples collected between the April 2001 and the June 2001 sampling events, this data implies that the reported decreases may be due to the overall MTBE mass reduction in First Zone and Second Zone ground water at the site AGE estimates the arithmetic average concentration of MTBE in ground water extracted between . 01 April and 30 June 2001 was 77 µg/1 The total volume of water processed through the ground Advanced GeoEnvironmental,Inc I