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' 12 February 2003 • AGE-NC Project No 97-0249 ' Page 4 of 5 ' Previous and current analytical results of ground water monitoring well samples are summarized in Tables 3 and 4 The laboratory reports(MAI Work Order No 0212122) and chain-of-custody forms are presented in Appendix C ' 4.0. SUMMARY AND CONCLUSIONS ' The implications from the December 2002 ground water monitoring event are as follows • Ground water elevation at the site appeared to have increased an average 5 45 feet between ' the September 2002 and the December 2002 ground water monitoring events(Table 2) 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 ' • Ground water flow direction at the site was generally inferred to be cast to southeast at an approximate gradient of 0 001, in the area of Three B's Truck Plaza well MW-4, ground water was inferred to be flowing radially inwards towards a depression of the water table located between Flag City Chevron wells MWA, MW-2 and EW-1 (Figure 3) 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 the inferred ground water flow direction • Ground water flow direction at the site does not appear to have been influenced by pumping ' of domestic water well DW-1 • The elevated TPH-g concentrations detected in water samples collected from wells MW-1, ' MW-2 and MW-3 (screened between 5 and 25 feet bsg) suggest that these wells may be screened within or near a"core area"of a dissolved petroleum hydrocarbon plume(Figure 4), however, significant TPH-g concentrations detected at well MW-6 suggest that at least two, 1 separate petroleum "core areas"may be present Historically,the area of greatest dissolved petroleum hydrocarbon-impact was encountered in the samples from wells MW-3 and MW-6 with lower petroleum hydrocarbon concentrations detected from in-between wells MW-1 and I MW-2 • The historical distribution of MTBE concentrations in Three B's Truck Plaza wells MW-1, MW-2,MW-4,MW-6 and Flag City Chevron well MW-7 have suggested the possibility of two separate dissolved MTBE-plumes (Figure 6) • The lateral extent of the dissolved petroleum hydrocarbon plume is not known toward the south, southwest, west, northwest and north of the area bound by wells MW-1 through MW-6, the vertical extent on the site is not known in any direction (Figures 4, 5 and 6) Advanced GeoEnvironmental,Inc