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29 December 2004 <br /> AGE-NC Protect No 95-0130 <br />' Page 7 of 10 <br /> I3 3 3 MASS CALCULATION OF RECOVERED PRODUCT <br /> The hydrocarbon mass removed during the SVE operating period was calculated using the equation <br /> M = C•Q•t <br /> where M = cumulative mass recovered(kg) <br /> C =vapor concentration (kg/m3) <br /> Q = extraction flow rate (m3/hr) <br /> t= operational period, in hours <br /> Between 31 August 2004 and 01 October 2004,the SVE unit operated a total of 744 hours(Table 6) <br /> The average analytical results (approximately 71,333 µg/l) of the influent SVE air flow samples <br /> I (Table 5), average flow rates (approximately 18 scfm, Table 6) and the operational period <br /> (744 hours) were used to calculate the approximate mass of extracted gasoline during this period <br /> IDuring the third quarter 2004 operational period, the mass of hydrocarbons extracted by the SVE <br /> system was calculated to be approximately 3,578 pounds, or equivalent to a volume of 573 gallons <br /> of gasoline The volume/mass calculations for extracted hydrocarbons are included with Appendix <br /> 10 H <br />' 4.0. SUMMARY AND CONCLUSIONS <br />' The implications from the September 2004 ground water monitoring event are as follows <br /> • Ground water flow direction within Hydrologic Units 1,2 and 3 was inferred to be towards <br />' the northeast at gradients between 0 004 ft/ft and 0 006 ft/ft (Figures 3 and 4) <br /> • Between January 1995 and August 2001, ground water elevations at the site generally <br /> increased from 44 feet to 23 feet below MSL, since August 2001 and present day, ground <br />' water elevations have generally fluctuated between 24 feet and 29 feet below MSL(Table 2) <br /> • Ground water at the site was generally observed between 44 and 45 feet bsg and was above <br />' the screened intervals of wells MW-1 through MW-5,MW-6(B-E),MW-7(B-E),VW-1C, <br /> VW-2A and VW-3A (i a screened below ground water elevation), and may not yield <br /> samples fully representative of shallowest ground water conditions <br />' • The greatest concentrations of Top Filling Station dissolved TPH-g and BTEX were detected <br /> in samples collected from wells MW-7, VW-2A and VW-1C (Figures 5 and 7) which is <br />' consistent with previous monitoring results TPH-g concentrations were detected as high as <br /> 190,000µg/l from well VW-2A Additionally,the deepest detection of dissolved TPH-g and <br />' Advanced GeoEnvironmental,Inc <br /> I f <br />