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x ' 17 September 2003 . AGE-NC Project No 98-0448 Page 7 of 9 ' Q =extraction flow rate (m3/hr) ' t=operational period, in hours Between 20 March 2003 and 23 June 2003,the SVE unit continuously operated approximately 2,280 hours The average of analytical results between SVE air flow sampling events (Table 5), average SVE air flow rates, (Table 6) and the operational period were used to calculate the approximate ' volume and mass of extracted gasoline during these periods During the above air monitoring events, the mass of hydrocarbons extracted from the SVE system ' was calculated to be approximately 25 42 pounds, or equivalent to an approximate volume of 4 06 gallons of gasoline extracted A plot of the cumulative volume(gallons) of hydrocarbons extracted to date is in Appendix E Added to the estimated 229 98 gallons of hydrocarbons extracted from the ' SVE system since 16 April 2001, the total volume of hydrocarbons extracted to date is estimated at 235 61 gallons The mass/volume calculations for extracted hydrocarbons are included with Appendix F 5.0. DISCUSSION AND CONCLUSIONS The implications from the June 2003 ground water monitoring event are as follows Ground water elevations ranged between 9 01 feet (MW-7) and 1127 feet (MW-4B) feet below MSL, the increase in ground water elevation`of approximately 0 64 feet between March 2003 and June 2003 maybe due to seasonal fluctuation The ground water elevation k at the site was within the screened intervals of wells MW-1 through MW-8 should be , representative of shallow ground water conditions,however well MW-4B is"drowned"with water approximately 24 feet over the screen and yields a sample more representative of deeper ground water conditions • Ground water elevation data collected on 17 June 2003 is not conclusive to suggest ground water mounding is occurring due to air sparging at the site • Ground water flow direction at the site was generally oriented toward the southwest, the gradient was estimated to be approximately 0 006 ft/ft north-northwest of well MW-2 (approximately 32 feet per mile), the gradient appeared much steeper at 0 016 ft/ft(845 feet per mile) south-southwest of well MW-2 • The elevated concentrations of petroleum hydrocarbons detected in the sample collected from well MW-2 indicates that this well is within the dissolved petroleum hydrocarbon"core area" of the plume (Figure 4) ' i Advanced GeoEnvironmental,Inc ,