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28 November 2005 ( � AGE-NC Project No 96-0232 Page 5 of 8 _ • Ground water elevations ranged between 1 11 feet (MW-1B&C) and 2 82 feet (MW-1OB) below MSL (Table 2) The net ground water flow direction in First Zone and Second Zone hydrogeologic units was generally inferred to be east-southeast to southeast at the Flag City Chevron site and east to east-northeast at the Three B's Truck Plaza site,hydraulic gradients were calculated to be approximately 0 003 ft/ft or less 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 the inferred ground water flow direction (Figures 3 and 4) • Generally MTBE concentrations declined in all wells in third quarter 2005 The most intense on-site Flag City Chevron MTBE concentration detected was from Second Zone well MW-8A at 560 µg/1 (Figure 6, Table 3), which is a noticeable decline from the 610 µg/1 concentration of the previous quarter Another significant MTBE concentration was detected in First Zone on-site well MW-2 at190 µg/1,which is a noticeable decline from the 220 µg/l of the previous quarter (Figures 5 and 6, Table 3) • The most intense off-site MTBE concentrations were detected north of the site from First Zone well MW-20A(McDonald's parking lot)at a concentration of 500 µg/1 and west of the site from First-Zone Three B's Truck Plaza's well MW-8A at a concentration of 300 µg/l, (01 the MTBE concentrations in well MW-20A continue to increase,albeit gradually, since the well was installed in 2004 • Low to moderate MTBE concentrations were detected in First Zone wells west of the site at Three B's Truck Plaza wells MW-2,MW-3,MW-13A and at Rocky's Restaurant from wells MW-7 and MW-16 (Figure 5) Low to moderate MTBE concentrations(as high as 37 µg/l) r _ were detected in Second Zone wells west-southwest of the site at Rocky's Restaurant wells MW-11A, MW-14, and MW-17, and west-northwest of the site at Three B's Truck Plaza, from wells MW-9A and MW-13B (Figure 6) Low to moderate MTBE concentrations (as high as 170 µg/1) were detected in Rocky's Upper Zone wells west of the site at Rocky Restaurant from wells MW-11B, MW-15 and MW-18 (Figure 7, Table 4) • Between the June 2004 and the September 2005 quarterly monitoring events, a significant MTBE decrease was reported at the northeastern-most well MW-19A(Banner Avenue),from 4,800 µg/l to 1,300 µg/l to 900 µg/1 to 240 µg/1 to 100 µg/l to 15 µg/1 (Figure 5, Table 3) • Low concentrations of TPH--d have been detected at various wells during previous quarterly monitoring events at Flag City Chevron During December 2004, a low concentration of TPH-d was detected in the water samples collected from well MW-12A AGE had previously asked McCampbell Analytical Laboratory to review the TPH-d sample chromatograms from MW-12A, the laboratory concluded that the low TPH-d detections from MW-12A did not have typical diesel characteristics,and that the detected chromatogram peaks were probably the result of biological interference Advanced GeoEnvironmental,Inc