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t� ail • 31 July 2000 AGE-NC Project No 97-0249 Page 4 of 5 4.0. SUMMARY AND CONCLUSIONS The implications from the May 2000 ground water monitoring event are as follows • With a ground water low reported at MW-6, ground water flow direction at the site appeared to be oriented generally towards the southwest at a gradient of approximately 0 003, 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 • Ground water elevation at the site decreased an average 3 98 feet from the February 2000 ground water monitoring event to the May 2000 ground water monitoring event • • A correlation was observed at wells MW-2 and MW-3 between increasing/decreasing TPH-g and BTEX concentrations and increasing/decreasing ground water elevations, a weaker correlation may be observed at MW-1 • The lateral extent of the dissolved petroleum hydrocarbon plume is not known toward the south, southwest, west, northwest, north and northeast of the current area bound by wells MW-i through MW-6, the vertical extent is not known • 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 may be screened within or near the "core area" of the dissolved petroleum hydrocarbon plume The area of greatest dissolved petroleum hydrocarbon-impact was observed in the area near MW-3 (Figure 4) • Elevated concentrations of dissolved petroleum hydrocarbons were detected in the samples collected from well MW-6, the TPH-g and TPH-d contour maps (Figures 4 and 5) suggest a secondary dissolved petroleum hydrocarbon plume in the area of MW-6 • The area of highest MTBE-impact appears to be the areas near well MW-4 and MW-6 • Laboratory results of grab ground water samples suggest that there is not an MTBE-impact to the domestic drinking water well at this time • AGE suspects the ethanol detected in DW-1 (May 2000)"grab"ground water sample was due to the coated bentonite pellets utilized during construction of well MW-13 Samples of the . `/4-inch coated bentonite pellets (Sinclair Services)were submitted in a VOA container filled Advanced GeoEnvironmental,Inc