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04 August 2000 • AGE-NC Project No 97-0300 ' Page 8 of 10 No other petroleum hydrocarbon constituents or fuel oxygenated compounds were detected during the laboratory analysis Analytical results of the ground water samples are summarized in Tables 5 and 6 The laboratory reports(McCampbell Analytical Inc I D 40652 through 40654) and chain-of- custody forms are presented in Appendix H ' 4 0. SUMMARY AND CONCLUSIONS The findings of the June 2000 drilling and well installation investigation results are as follows ' • A fine sandy, clayey silt was encountered at depths of 5 10 30 35 40 45 55 and 60 feet bsg, a silty fine sand was encountered at depths of 15, 20, 25 and 50 feet bsg At depths in ' excess of 65 feet bsg, a gravelly fine to coarse sand was encountered General lithology beneath the site in cross-sectional view is depicted in Figures 3 and 4 ' • Saturated soil was observed in soil sample duplicates at 40 feet bsg in borings P-7, MW-1, MW-2 and MW-3, ground water levels were measured at approximately 38 feet bsg utilizing le a Solinst water level meter INone of the constituents of concern were detected by laboratory analysis of selected soil samples ' • Based on data collected from P-7, the vertical extent of petroleum hydrocarbon-impacted soil underlying the former UST pit does not appear to extend beyond 40 feet bsg in the area ' beneath the former USTs (Figures 10 and 11) • From the former UST tank pit,the horizontal extent of petroleum hydrocarbon- impacted soil appears to extend approximately 5 feet toward the northwest (P-1), 10 feet toward the I southwest between P-3 and P-6, 15 feet southeast (MW-3) and 20 feet northeast between MW-2 and P-5 (Figure 12) • The major portion of the petroleum hydrocarbon soil-impact at the site appears to have been caused by a gasoline release, a minor portion may have been the result of a diesel release • The results of the microbial enumeration and physicochemical analysis indicated that hydrocarbon-degrading microorganisms were detected at 26,000 CFU per gram The laboratory indicated that these physicochemical conditions at the site were well within the range necessary to support microbial growth and bioremedial activity • Based on the guide How to Evaluate Alternative Cleanup Technologies For UST Sites (October 1994) published by the United States Environmental Protection Agency (EPA) Office of USTs, intrinsic permeability values between the magnitude of 10 2 and 10-8 are • generally adequate for soil vapor extraction (SVE) technology (Exhibit IT& Intrinsic Advanced GeoEnvironmental,ine I