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17 December 1998 • AGE-NC Project No 95-0173 Page 3 of 5 elevation data for MW-1 through MW-12, VW-1, AW-1B and AW-2B during the October 1998 ground water monitoring event is depicted in Figure 3 During the October 1998 monitoring event, ground water was approximately 4 feet above the top of the screened intervals of monitoring wells MW-1 through MW-4, approximately 24 feet above screened interval of AW-1B and approximately 34 feet above screened interval of AW-2B As a result, the screened intervals from these wells are completely submerged (drowned), and may not yield water samples fully representative of ground water conditions near the top of the saturated zone where fuel hydrocarbons would be expected to have the greatest impact Ground water elevation data collected in October 1998 in the area of MW-1 through MW-12 and VW-1 indicated that the ground water flow direction was generally toward the northeast at a gradient of 0 003 ft/ft, or approximately 16 feet per mile (Figure 3) 3 2 LABORATORY RESULTS OF GROUND WATER SAMPLES During the October 1998 sampling event,TPH-g was detected in water samples collected from MW- D through MW 4, MW-6, MW-8, MW-9, MW-12, VW-1, AW-1B and AW-2B at concentrations ranging between 57 micrograms per liter(4zg/1)and 150,000µg/l,respectively, TPH-d was detected in water samples collected from wells MW-1 through MW-4,MW-6,MW-8,MW-11,MW-12,VW- 1 AW-1B and AW-2B at concentrations ranging between 68 ,ug/l and 11,000 mg/l, however the laboratory reported that the chromatograms for the samples did not have typical diesel characteristics It was noted in the laboratory reports that the diesel sample containers from MW-2 and MW-9 were broken when received by the laboratory, and the samples were not analyzed Various BTE&X compounds were detected in water samples collected from wells MW-1 through MW4, MW-6,MW-9, VW-1,AW-1B and AW-213 at concentrations ranging between 4 7,g/l and 37,000 ,ug/1 (toluene, VW-1) The greatest benzene concentration was reported from MW-6 at a concentration of 28,000µg/1 Detection of MTBE by EPA Method 8020 was confirmed in a water sample collected from AW-2B by EPA Method 8260 at a concentration of 1 5 ,ug/l MTBE was not confirmed in the sample from MW-9, but was detected utilizing EPA Method 8020 at a concentration of 0 75 Ag/l Based on historical detection,MTBE may be present at wells MW-1 through MW-4, VW-I and AW-IB, but may have been masked due to raised detection limits None of the fuel oxygenating compounds were detected in the analyzed water samples However, . based on historical detection, DIPE and/or TBA may be present at MW-3, MW-6, VW-I and AW- Advanced GeoEnviron mental,Inc. I