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1 a ' 14 February 2006 AGE-NC Project No 98-0448 ' Page 7 of 9 ' volume and mass of extracted gasoline during these periods Note the detection limit of analytical method was used for mass calculation During the above air monitoring events, the mass of hydrocarbons extracted from the SVE system was calculated to be approximately 30 pounds, or ' equivalent to an approximate volume of 4 82 gallons of gasoline extracted A plot of the cumulative volume (gallons) of hydrocarbons extracted to date is in Appendix E Added to the estimated 315 27 gallons of hydrocarbons extracted from the SVE system since 16 April 2001,the total volume of hydrocarbons extracted to date is estimated at 320 09 gallons The mass/volume calculations for extracted hydrocarbons are included with Appendix F 5.0. DISCUSSION AND CONCLUSIONS ' The implications from the November 2005 ground water monitoring events are as follows • The November 2005 ground water elevations at the site ranged approximately between 10 49 ' feet (MW-7) and 12 34 feet (MW-4B) below MSL The ground water elevation at the site were within the screened intervals of wells MW-1, MW-2, MW-4A, MW-6, MW-7 and MW-8, and 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 (Table 2) ' • Ground water elevation data collected on 23 November 2005 did not suggest that ground water mounding was occurring due to air spargmg at the site (Figure 3) • Ground water flow direction at the site was toward the south-southwest, the ground water gradient was estimated to be approximately 0 008 ft/ft (Figure 3) • No other petroleum hydrocarbons were detected from sampled monitoring wells • Between the September 2005 and November 2005 monitoring events, TPH-g was not detected for the 2"d consecutive sampling event in well MW-2, benzene levels were not detected from MW-2 for the 10" consecutive monitoring event, toluene and ethylbenzene ' were not detected for the 2"consecutive event and total xylenes decreased to non detect this quarter The trend of decreasing concentrations may be attributed to the air sparge activities being performed at wells AW-4, AW-5 and MW-4B (Table 3) Based on SVE/IAS remediation data collected between 07 September 2005 and 22 November 2005, AGE concludes • The volume of hydrocarbons extracted by the SVE system was calculated to be approximately 30 pounds during the fourth quarter 2005, or equivalent to an approximate volume of 4 82 gallons of gasoline extracted (Appendix F) or approximately one percent Advanced GeoEavironmental,Inc I