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F 30 October 2002 AGE-NC Project No 01-0827 ' Page 4of5 3 3 GROUND WATER GRADIENT AND FLOW DIRECTION On 04 September,depths to ground water ranged from 22 26 to 23 94 feet below the well casing tops ' (Table 3) The ground water elevations at the site ranged from 12 36 feet (MW-5) to 12 65 feet (MW-2)below mean sea level(MSL) The ground water flow direction was inferred to be northeast at a gradient of 0 002 ft/ft at the former UST area (Figure 3) 3 4 ANALYTICAL RESULTS OF GROUND WATER SAMPLES ITPH-g was detected in two of the seven ground water samples, at concentrations ranging from 60 µg/1(MW-1)to 5,500 ug/l(VW-2d) TPH-d was not detected in the seven ground water samples collected BTEX compounds were detected in samples MW-1 and VW-2d at maximum concentrations of 1,040µg11 benzene, 112 µg/1 toluene, 126 µg/l ethylbenzene and 234 µg/l xylenes, respectively, in the sample from well VW-2d No other ground water samples contained detectable concentrations of BTEX MTBE was detected in ground water samples MW-1, VW-2d and VW-5d at concentrations of 1 6 gg/l,62 µg/1 and 1 6 gg/l,respectively TAME was detected in sample VW-2d at a concentration of 38 µg/1 The chlorinated solvent 1,2-DCA was not detected in ground water samples The analytical results are summarized in Tables 4 and 5 A copy of the laboratory report (PET Lab ID 16638-01 to 07) and chain-of-custody form are included in Appendix D 4.0. SUMMARY AND CONCLUSIONS Based on the data collected from the site, AGE finds • Hydrocarbons were not extracted from the SVE network during the monitoring period The concentrations of hydrocarbons in the SVE influent has declined below detection limits for two consecutive sampling events,during normal SVE operation and monitoring However, the SVE should continue operation during IAS operation, to potentially encourage I volatilization and collect any vapors • Ground water was encountered at a depth of approximately 23 feet bsg, ground water flow was inferred to be towards the east under a gradient of 0 002 ft/ft I • The maximum concentrations of petroleum hydrocarbon and BTEX compounds in ground . water were detected in the ground water sample collected from on-site vapor well VW-2d Advanced GeoEnvironmental,Inc