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27 June 2002 <br /> AGE-NC Project No, 98-0520 <br />' Page 6 of 8 . <br />' The BTEX.eompounds toluene, ethylbenzene and xylenes were detected in samples MW-6-35, <br /> MW-8-30 and MW-9-20 at maximum concentrations of 0.093 mg/kg, 0.83 mg/kg and 0.7 mg/kg, <br /> respectively, in the sample from MW-9-20. Benzene was not detected in any of the samples <br />' analyzed. <br /> MTBE was detected at a concentration of 0.0075 mg/kg in soil sample MW-9-25. <br /> No other analytes were detected in the soil samples analyzed. Analytical results of soil samples are . <br /> summarized on'Table 1. Cross-sections showing the vertical and lateral extent of hydrocarbon-• . <br /> impacted soil are provided as Figures 5 through 8. The laboratory reports (MAI I.D. Nos.82460- . <br /> ' 82472), quality assurance and quality control (QA/QC) report and chain-of-custody forms are <br /> included in Appendix D. <br /> 3.4. GROUND WATER GRADIENT AND FLOW DIRECTION <br /> ' The elevation of ground water in each well was calculated by subtracting the depth to ground water <br /> from the surveyed casing elevations (Table 2). Depths to ground water ranged from 20.05 feet to <br /> ' 20.99 feet below the tops of the well casings. Ground water elevations at the site ranged from <br /> 15.96 feet in MW-8 to 16.37 feet in MW-10 relative to mean sea level (MSL). <br /> ' The ground water flow direction was determined using ground water elevation data(Figure 9). The <br /> ground water table underlying the site formed a trough-like depression,with the base of the trough <br /> plunging north-northwest under an'average gradient of 0.004 ft/ft. The eastern limb of the trough <br /> ' flows westward under an average gradient of 0.005 ft/ft; the western limb's flow direction is <br /> northeast under a 0.004 ft/ft gradient. <br /> 3.5. RESULTS OF WATER SAMPLE ANALYSIS <br /> 'Y TPH= was detected in the ground water samples collected from wells MW-1 through MW-5,MW-8 <br /> g , <br /> and MW-9 at concentrations ranging between 280 micrograms per liter (µg/1) in well MW-9 and' <br /> 9,000 µg/1 in well MW-5. <br /> The BTEX compounds toluene, ethylbenzene and xylenes were detected in sample' s-from wells <br /> ' MW-1 through MW-5 and MW-9; the maximum concentrations were detected in the water sample <br /> from MW-5 at 14 µg/1,8.6 µg/1 and 220 µg/1,respectively.Benzene was not detected in the samples <br /> analyzed. <br /> ' Advanced CeoEnvironmental,Inc. <br /> 1 <br />