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1 ' 15 January 2001 AGE-NC Project No 96-0232 ' Page 18 of 20 ' water flow direction appeared to oriented east-southeast at an approximate gradient of 0 001 ft/ft or less (Figure 16) and the Primary Aquifer Zone ground water flow direction appeared to be oriented southeast at an approximate gradient of 0 0004 ft/ft or less (Figure 17) ' • First and Second Zone ground water flow direction and gradient during the Flag City Chevron monitoring event appeared to be influenced by ground water extraction activities ' at EW-2, EW-4, EW-6 and EW-9 (south trench-line), Primary Aquifer Zone ground water flow direction at the site may have been influenced by pumping of the Rocky's Restaurant and Three B's Truck Plaza domestic drinking water wells ' Due to the low ground water gradient at the site, small variations in ground water measurements or changes of recharge/discharge of the local ground water could greatly modify ground water flow direction • The greatest concentrations of dissolved MTBE in on-site First Zone monitoring wells were detected in MW-1 at concentrations as high as 1,800µg/1 (Figure 18), lesser concentrations ' of MTBE were detected from MW-4 and MW-6A Dissolved MTBE was detected in Second Zone monitoring well MW-9A (Figure 19) • The greatest concentrations of dissolved MTBE detected in the extraction wells were in samples collected from EW-4, EW-6 and EW-7 at concentrations as high as 890,ug/l (Figure 18), lesser concentrations of MTBE were detected in samples from extraction wells EW-2, 1 EW-5, EW-8, EW-9 and EW-10 • The greatest concentration of off-site dissolved MTBE was detected in MW-11A (screened 40 to 50 feet bsg) at a concentration of 110,ug/l, low concentrations of MTBE were detected ' off-site from MW-6A (screened 7 to 27 feet bsg), MW-6B (screened 43 to 48 feet bsg), MW-7 (screened 41/2 to 241/2 feet bsg), MW-12A (screened 10 to 20 feet bsg) and MW-13A ' (screened 10 to 20 feet bsg) at concentrations as high as 56 ugll (MW-7) • Low concentrations of dissolved TPH d were encountered in MW-6B (screened 43 to 48 ft bsg), MW-9B (screened 95 to 105 feet bsg), MW-12A (screened 10 to 20 feet bsg) and MW-13A (screened 10 to 20 feet bsg) 10.0. 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 Advanced GeoEnvironmental,Inc