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�N N 19 July 2004 AGE-NC Project No 95-0109 Page 5 of 7 3.0. FINDINGS Soil descriptions were determined from field data collected between 12 April and 14 April 2004 Ground water elevation and flow direction were Inferred from the field data The petroleum hydrocarbon-Impact to ground water was quantified by laboratory analysis of the ground water samples 31 STRATIGRAPHY Generally, light brown to brown clayey silt and sandy silt were encountered from surface grade to approximately 13 feet bsg Orange brown to green brown to brown silty sand to sand and gravelly sand was encountered from 13 feet to 23 feet bsg Generally yellow brown to brown sandy silt and silt was found around 25 feet bsg In the monitoring well borings, silty sand and sand was encountered from after 25 feet bsg to dust above 40 feet bsg The borings for the ozone wells were silty sand and sandy silt at 30 and 35 feet bsg At 40 feet bsg, all borings generally had some clayey silt in varying colors Ozone borings contained silty sand, sand and gravelly sand from 45 feet bsg to total depth The majority of the soil below 40 feet bsg in the monitoring well borings was silty sand, sand and gravelly sand Organic vapor was detected in some soil samples collected from ozone well borings OW-2 and OW-3 at concentrations as high as 490 parts per million(ppm)in the sample collected from 25 feet bsg in boring OW-3 PID data is included on the boring logs (Appendix A) 3 2 GROUND WATER GRADIENT AND DIRECTION On 26 June 2004, the depth to ground water ranged from 56 73 feet to 60 75 feet below the tops of the well casings Ground water elevations at the site ranged from 2 51 feet below mean sea level (MSL)in well MW-5 to 6 97 feet below MSL In well MW-17 Ground water levels were within the screened Intervals of water-table wells MWA through MW-14 and MW-16, but ranged from approximately 15 to 52 feet above the screened intervals of the deep-screened wells MWA 5, MW-17,MW-18 and MW-19 Data from wells MW-1 through MW-5 were not used to infer ground water flow direction or gradient because these wells are screened at different Intervals than the remaining wells The ground water for the well network was Inferred to be flowing towards the south The ground water gradient ranged from approximately 0 002 ft/ft on-site to 0 005 ft/ft off-site Figure 3 Illustrates the contoured ground water elevations, historical ground water flow directions are summarized on i Table 4 Advanced GeoEnvironmental,Inc