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i 21 June 2004 AGE-NC Protect No 97-0249 IPage 5 of 7 3 14 Hydrologic Unit 4 Net ground water flow from Hydrologic Unit 4 (90 to 110 feet bsg) was inferred to be towards the east-northeast at both the Flag City Chevron and Three B's Truck Plaza sites,at hydraulic gradients of 0 001 ft/ft or less (Figure 7) ' 3 1 5 Hydrologic Unit 6 Net ground water flow from Hydrologic Unit 6 (130 to 150 feet bsg) appeared to be toward the Isouth-southeast at the Flag City Chevron site and toward the east-southeast at the Three B's Truck Plaza at hydraulic gradients of 0 002 fl/ft or less (Figure 8) I 3 2 LABORATORY RESULTS OF MONITORING WELL GROUND WATER SAMPLES A total of forty-one ground water samples were submitted to McCampbell Analytical Inc , a DHS- certified laboratory, for analysis lie TPH-g was detected ml 8 water samples collected from wells MW-1,MW-2,MW-3,MW-5,MW-6, MW-7(B-D),MW-8 (A-E)and MW-10 (A and E) at concentrations as high as 21,000 micrograms ' per liter (µg/1) in the sample collected from MW-3 The estimated extent of dissolved TPH-g in Hydrologic Unit 1 is depicted in Figure 9 ' TPH-d was detected in six water samples collected from wells MW-1, MW-2, MW-3, MW-6 and MW-8 (A and C) at concentrations as high as 3,200 µg/l in the sample collected from MW-3, however, the laboratory reported the TPH-d sample chromatograms to either have significant gasoline range compounds, diesel range compounds, oil range compounds or unmodified gasoline/diesel The estimated extent of dissolved TPH-d mHydrologic Unit 1 is depicted in Figure 10 Various BTEX constituents were detected in 24 water samples collected from wells MW-1,MW-2, MW-3, MW-5, MW-6, MW-7 (A-E), MW-8 (A-F), MW-9 (B and C) and MW-10 (A-F) at ' concentrations as high as 4,200µg/1 benzene,450µg/1 toluene,610 pg/1 ethylbenzene and 2,100µg/l xylenes in the sample collected from MW-3 The greatest benzene-impact was also detected in the ground water sample collected from well MW-3 at a concentration of 4,200 pg/l MTBE was detected by EPA Method 8260 in 12 ground water samples collected from wells MW-1, MW-2, MW-4, MW-8 (A), MW-9 (A and B), MW-10 (A-C) and MW-11 (A-C) at concentrations as high as 64 gg/1 (MW-8A) The estimated extent of dissolved MTBE in Hydrologic Units 1 and 2 are depicted in Figures 11 and 12, respectively IAdvanced GeoEnvironmental,Inc I