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18 February 2003 <br /> AGE-NC Project No 96-0229 <br /> Page 7 of 9 <br /> analytical results of selected soil samples are summarized in Table 5 The laboratory reports <br /> (McCampbell Analytical Inc Lab I D No 0210042) and cham-of custody forms are included in <br /> IAppendix F <br /> 4.0 SUMMARY AND CONCLUSIONS <br /> The findings of the September 2002 drilling and well installation investigation results are as follows <br /> 1 A clayey, silty fine sand was encountered at depths of 5 feet, 40 feet and 45 feet bsg, a silty <br /> 1 clay was encountered at a depth of 10 feet bsg, either a fine sandy, clayey silt underlain by <br /> clay(MW-11) or silty sand (MW-12)was encountered at depths of 15 feet and 20 feet bsg, <br /> a fine to coarse sand with some gravel was encountered at depths of 20 feet, 25 feet, 30 feet <br /> and 35 feet bsg General lithology beneath the site is depicted in geologic cross-sectional <br /> views E-E'and F-F' (Figures 5 and 6) <br /> • Saturated soil was observed in soil sample duplicates at 35 feet bsg in borings MW-11 and <br /> MWA 2, ground water levels were measured at approximately 32 feet bsg utilizing a Solinst <br /> r . water level meter(Appendix A) <br /> • None of the constituents of concern were detected by laboratory analysis of selected soil <br /> samples (Table 5) <br /> • Based on analytical data compiled in cross Section F-F', the vertical Ment of perroleum <br /> hydrocarbon-impacted soil underlying the former UST pit does not appear to extend much <br /> Ebeyond 65 feet bsg (Figure 11) <br /> • From the former UST tank pit, the petroleurri hydrocarbon-impacted soil plume appears to <br /> extend at least 200 feet towards the northeast, to the vicinity of well MW-6 (Figure 11) <br /> The implications from the findings of the November 2002 ground water monitoring event are <br /> • Ground water flow direction at the site was inferred to be towards the northeast at an <br /> 1 approximate gradient of 0 003 ft/fl This appears to be the prevailing flow direction for the <br /> i area(Figure 7) <br /> • Due to the low hydraulic gradient at the site,slight variations in ground water measurements <br /> or changes of recharge/discharge of the local ground water could greatly modify the inferred <br /> ground water flow direction <br /> • The elevated concentrations of petroleum Hydrocarbons detected in samples collected from <br /> wells MW-1, MW-2, MW-3 and MW-6 indicate that these wells are within or near the <br /> dissolved petroleum hydrocarbon "core area" of the plume (Figure 8) <br /> I <br /> Advanced GeoEnvironmental,Inc <br /> I <br />