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S07 November 2002 AGE-NC Project No 96-0263 Page 4 of 6 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION The elevation of ground water to each well was calculated by subtracting the depth to ground water from the surveyed well casing elevations (Table 1) For the June 2002 sampling event, depths to ground water ranged from 6 80 feet to 7 90 feet below the tops of the well casings Ground water elevations at the site ranged from 28 94 feet above mean sea level(MSL)in well MW9 to 29 83 feet above MSL in well MW11 The groundwater flow direction was determined by contouring the groundwater elevation data The ground water at the site was inferred to be flowing to the north-northwest at an average gradient of 0 005 feet/feet or 26 feet per male The groundwater contours are depicted on Figure 3 Elevation data from deep-screened well MW-6 (well-screened interval between 27 and 32 feet bsg) was not used to determine ground water flow direction 3 2 ANALYTICAL RESULTS OF SOIL SAMPLES A total of 2 soil samples were collected from well boring OWI TPH-g was detected in the 15- and 20-foot soil samples at concentrations of 6 8 and 2 0 mg/kg, respectively BTEX were detected in both soil samples at concentrations as high as 0 11 mg/kg benzene, 0 36 mg/kg toluene, 0 27 mg/kg ethylbenzene, and 1 17 mg/kg total xylenes MTBE was detected an both soil samples at concentrations of 0 80 mg/kg and 0 37 mg/kg, respectively No other analytes were detected above the laboratory reporting limits in the soil samples Analytical results of soil samples are summarized on Table 2 The laboratory reports(CTEL Lab I D No 0206-175-1 and 0206-175-2), quality assurance and quality control(QA/QC)report and chain-of- custody forms are included in Appendix D 33 ANALYTICAL RESULTS OF GROUND WATER SAMPLES TPH-g was detected in the water samples collected from monitoring wells MW2, MW4, MW5, and MW7 at concentrations ranging from 340 rrucrograms per liter (µg/1) in MW4 to 16,000 µg/l m MW7 Various BTEX compounds were detected in the water samples collected from monitoring wells MW2 and MW4 through MW7 at maximum concentrations of 750 µg/1 benzene, 480 µg/1 toluene, 26 µg/1 ethylbenzene and 300 µg/l xylenes, in sample MW7