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QU ■3 . 30 October 2004 AGE-NC Project No 96-0232 Page 10 of 14 Analytical Inc Work Order 0409206) and chain of custody forms are presented in Appendix G, GeoTracker confirmation pages of the submitted laboratory electronic deliverable format(EDF)files are Included in Appendix H 4.0. SUMMARY OF FINDINGS FROM QUARTERLY ACTIVITIES Previous soil characteristics data obtained by a CPT investigation enabled AGE to define five Informal hydrogeologlc units (Final Remediation Plan, dated 31 August 2000) The Informal hydrogeologlc units were defined as First Zone (10-35 feet bsg), Second Zone (40-60 feet bsg), Rocky's Upper Zone (65-75 feet bsg), Secondary Aquifer Zone (85-105 feet bsg), and Primary Aquifer Zone (130-150 feet bsg) The Rocky's Upper Zone was the shallowest groundwater zone screened in the destroyed Rocky's domestic drinking water well The results of pump and treat ground water remediation between 15 June 2004 and 17 August 2004 is as follows • Approximately 885,468 gallons of MTBE-impacted ground water were continuously extracted from wells EW-4, EW-5, EW-7, EW-8 and EW-10, which are completed in the First Zone aquifer (Appendix A) A total volume of approximately 27,086,201 of MTBE- impacted water has been treated at the site since the start-up period in November 2000 (Table 5) • Ground water pump-and-treat operations were suspended at the site on 17 August 2004 due to the lack of cost-effectiveness for clean-up of MTBE-impacted ground water • MTBE concentrations were detected from the July 2004 monthly water samples collected at the influent end of the treatment system at a concentration of 47 µg/l • Laboratory analysis of pump-treat effluent samples and did not detect any MTBE during the third quarter 2004 • Between 15 June 2004 and 17 July 2004, the mass of MTBE removed from the extracted ground water was calculated to be 0 3 5 pounds(Table 5,Appendix C) A plot of cumulative ground water pump and treat mass removal versus time and a plot of influent ground water MTBE concentrations versus time are included in Appendix D The results from the ground water monitoring and sampling events performed in September 2004 are as follows Advanced GeoFnv■ronmental,Inc