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' 16 December 2005 . AGE-NC Project No 97-0249 ' Page 5 of 8 ' 0 001 ft/ft or less, the gradient is essentially flat at the Three B's Truck Plaza(Figure 6) ' 3 14 Hydrogeologic Unit 6 Ground water elevation data collected in the Hydrogeologic Unit 6(130 to 150 feet bsg) inferred a ' net ground water flow direction at the Flag City Chevron towards the east-southeast at a hydraulic gradient of 0 002 ft/ft or less The ground water gradient at the Three B's Truck Plaza inferred a net ground water flow direction towards the east at a hydraulic gradient of 0 001 ft/ft or less(Figure 7) 3 2 LABORATORY RESULTS OF MONITORING WELL GROUND WATER SAMPLES ' A total of forty ground water monitoring well samples were submitted to MAI for analysis, in addition, one domestic water well sample was submitted for analysis ' TPH-g was detected in ground water samples MW-1,MW-2,MW-3,MW-5,MW-7A,MW-8(A-C) and MW-10 (A-C and E) at a maximum concentration of 44,000 micrograms per liter(µg/1) in the ' sample collected from MW-3 The estimated extent of dissolved TPH-g in Hydrologic Unit I is depicted on Figure 8 TPH-d was detected in ground water samples MW-1,MW-2,MW-3,MW-5,MW-6,MW-8(A and C) and MW-l0A at a maximum concentration of 5,700 µg/1 in the sample collected from MW-3 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 in Hydrologic Unit 1 is depicted on Figure 9 Various BTEX constituents were detected in ground water samples MW-1, MW-2,MW-3, MW-5, MW-6, MW-7 (A-E), MW-8 (A-F), MW-9C, MW-10 (A-F), MW-I 1E and MW-12 (D-F) at concentrations as high as 7,100 µg/l benzene, 700 µg/l toluene, 1,400 µg/1 ethylbenzene and 4,800 µg/1 xylenes in the sample collected from MW-3 MTBE was detected by EPA Method 8260 in ground water samples MW-1,MW-2, MW-4,MW-5, MW-6, MW-8 (A-C),MW-9(A-B),MW-10(A-C)and MW-11 (B-C)at concentrations as high as 120 µg/l (MW-8A) The estimated extent of dissolved MTBE in Hydrologic Units I and 2 are Idepicted on Figures 10 and 11, respectively TBA was detected in ground water samples MW-1, MW-5, MW-8A and MW-l0A at maximum concentrations of 110 µg/l from well MW-1, 1,2-DCA was detected in ground water samples MW-10 (A, B and E) at a maximum concentration of 9 3 µg/1 (MW-10A) IAdvanced GcoEnvironmental,Inc