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r 10 December 2001 • AGE-NC Project No 96-0249 rPage 4of6 MTBE was detected In water samples collected from MW-1, MW-4 and MW-6 utilizing EPA Method 8260 Modified at concentrations as high as 110µgll No other fuel oxygenated compounds were detected In any other ground water samples ILaboratory analysis of samples collected from domestic drinking water wells DW-1 and RDW-1 did not detect any constituents of concern above laboratory reporting limits rPrevious and current analytical results of ground water monitoring well samples are summarized In Tables 2 and 3, analytical results of the ground water samples collected from the domestic drinking I water wells DW-1 and RDW-1 are summarized In Table 4 The laboratory reports (McCampbell Analytical Inc I D No 77224 through 77229, 77238 and 77239) and chain-of-custody forms are presented In Appendix C r 4.0. SUMMARY AND CONCLUSIONS The implications from the September 2001 ground water monitoring event are as follows lie o Ground water flow direction for the area bound by Three B's Truck Plaza wells MW-1 through MW-6 was inferred to be toward the west at a gradient of 0 004 ft/ft, or approximately 21 feet per mile and less (Figure 3) G Due to the low gradient at the site, slight variations In ground water measurements or changes of recharge/discharge of the local ground water could greatly modify ground water flow direction • Ground water flow direction at the site may have been Influenced by pumping of the Three B's Truck Plaza domestic drinking water well • The ground water elevation at the site was within the screened Intervals of wells MW-1 through MW-6 which should yield samples fully representative of shallow ground water conditions (First Water Zone) • Ground water elevation at the site decreased an average 4 14 feet between the March 2001 and the June 2001 ground water monitoring events and decreased another 3 60 feet between the June 2001 and September 2001 ground water monitoring events (Table 1) • The lateral extent of the dissolved petroleum hydrocarbon plume Is not known toward the south, southwest, west, northwest, north and northeast of the area bound by wells MW-i through MW-6, the vertical extent on the site is not known(Figures 4, 5, 6 and 7) • The elevated petroleum hydrocarbon concentrations detected In water samples collected from wells MW-1, MW-2, MW-3 (screened between 5 and 25 feet bsg) suggest that these wells IAdvanced GeoEnvironmental,Inc