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1 ' 25 March 2004 AGE-NC Project No 97-0249 ' Page 5 of 7 3 1 5 Hydrologic Unit 6 ' Ground water flow from Hydrologic nit 1 t 1 Three U 6{ 30 a 50 feet bsg} appeared to be east at the hr e ' B's Truck Plaza site, at a hydraulic gradient of 0 001 ft/ft, towards an essentially flat ground water gradient at Flag City Chevron (Figure 8) ' 3 2 LABORATORY RESULTS OF MONITORING WELL GROUND WATER SAMPLES ' A total of forty ground water samples were submitted to McCampbell Analytical Inc , a DHS- certified laboratory, for analysis ' TPH-gwas detected m14 water samples collected from wells MW-1,MW-2,MW-3,MW-5,MW-6, MW-7 (C and E), MW-8 (A-E) and MW-10 (A and F) at concentrations as high as 12,000 micrograms per liter(µg/1) in the sample collected from MW-3 The estimated extent of dissolved ' TPH-g in Hydrogeologic Unit 1 is depicted in Figure 9 TPH-d was detected in eight water samples collected from wells MW-1, MW-2, MW-3, MW-5, MW-6, MW-8 (A and C) and MW-11A at concentrations as high as 1,600 µg/1 in the sample lie 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 in Hydrogeologic Unit 1 is depicted in Figure 10 Various BTEX constituents were detected in 27 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 (A-E) and MW-10 (A-F) at concentrations as high as 3,000 µg/1 in the sample collected from MW-3 The greatest benzene- impact was detected in the ground water sample collected from well MW-3 at a concentration of 3,000 µg/1 ' MTBE was detected by EPA Method 8260 in 14 ground water samples collected from wells MW-1, MW-2, MW-3, MW-4, MW-8 (A and B), MW-9 (A and B), MW-10 (A-C) and MW-11 (A-C) at concentrations as high as 99µg/l(MW-8A) The estimated extent of dissolved MTBE in Hydrologic Units 1 and 2 are depicted in Figures 11 and 12, respectively TBA was detected in 3 ground water samples collected from wells MW-1, MW-8A and MW-11A at concentrations as high as 56 µg/1 in the sample collected from MW-8A, 1,2-DCA was detected in 2 ground water samples collected from wells MW-10A and MW-11A at concentrations of 6 µg/1 and 2 6 µg/1, respectively No other fuel components were detected in the ground water samples Previous and current analytical results of ground water monitoring well samples are summarized in Tables 3 and 4 The laboratory reports(McCampbell Analytical Inc Work Order Nos 0312190,0312208 and 0312207)and chain- Advanced GeoEnviron mental,Inc f