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. 30 January 2004 <br /> ` AGE-NC Project No 96-0232 <br /> Page 10 of 15 <br /> 3 4 12 Second Zone Aquifer <br /> Ground water elevation data collected in the Second Zone Aquifer (40 to 60 feet bsg) inferred a <br /> radially-inward ground water flow In the area of Flag City Chevron well MW-6B, net flow is <br /> southwards at ground water gradients of 0 002 Rift or less Ground water flow direction at the Three <br /> B's Truck Plaza was inferred to be towards the east-southeast at hydraulic gradient of 0 002 ft/ft or <br /> less (Figure 5) <br /> 3 4 13 Secondary Aquifer Zone <br /> Ground water flow in the Secondary Aquifer Zone (85 to 105 feet bsg) appeared to be towards the <br /> east-northeast at both the Flag City Chevron and Three B's Truck Plaza sites, at hydraulic gradients <br /> of 0 001 ft/ft or less (Figure 6) <br /> 3 4 14 Priniga Aquifer Zone <br /> Ground water flow to the Primary Aquifer Zone (130 to 150 feet bsg) appeared to be east at the <br /> Three B's Truck Plaza site, at a hydraulic gradient of 0 001 ft/ft, towards an essentially flat ground <br /> water gradient at Flag City Chevron (Figure 7) <br /> 3 4 2 Laboratory Results of Ground Water Samples <br /> During the December 2003 sampling event, TPH-d was detected In the sample collected from <br /> MW-12A at a concentration of 230 gg/1 The laboratory report noted that the TPH-d sample <br /> chromatogram had significant diesel range compounds <br /> MTBE (utilizing EPA Method 8260M) was detected in water samples collected from monitoring <br /> wells MW-8A,MW-9A,MW-11 B,MW-11D,MW-12B,MW-13A,MW-13B andMW-14 through <br /> MW-18 at concentrations as high as 400 [.g/1 (MW-8A), isoconcentration maps displaying the <br /> estimated extent of dissolved MTBE in First Zone and Second Zone aquifer are depicted in Figures <br /> 8,9 and 10 In addition,MTBE was detected in water samples collected from extraction wells EW-2, <br /> EW-4, EW-5, EW-7 through EW-10 at concentrations as high as 36 4g/l (EW-7) <br /> No other constituents of concern were detected above laboratory reporting limits in the water <br /> samples collected during the fourth quarter 2003 sampling event Analytical results of ground water <br /> monitoring well samples are summarized in Tables 5 and 6 The laboratory reports (McCampbell <br /> Analytical Inc work order nos 0312187, 0312188, 0312189 and 0312209) and chain-of-custody <br /> forms are presented in Appendix H <br /> Advanced GeoEnvironmental,Inc <br />