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' 11 August 2003 AGE-NC Project No 96-0232 Page 11 of 15 Analytical Inc work order nos 0306568, 0306601 and 0307008) and chain-of-custody forms are presented 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 hydrologic units (Final Remediation Plan, dated 31 August 2000) The informal hydrogeologic units were defined as First Zone (10-35 feet bsg), Second Zone (40-60 feet bsg), I 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 ground water zone screened in the destroyed Rocky's domestic drinking water well The results of pump and treat ground water remediation between 25 March 2002 and 25 June 2003 is as follows • Approximately 2,090,669 gallons of MTBE-impacted ground water were extracted from wells EW-4, EW-5, EW-7 and EW-8, which were completed in the First Zone aquifer (Appendix A, Table 8) A total volume of approximately 21,589,805 gallons of MTBE- impacted water has been treated at the site since the start-up period in November 2000 (Table 8) O Decreasing MTBE concentrations were detected from water samples collected at the influent-end of the treatment system at concentrations of 49 µg/1, 37 µg/1 and 17 µg/1 ' a Laboratory analysis of the 25 June 2003 effluent-end water samples detected MTBE at a concentration of 0 78 µg/l (Table 1) The pump-and-treat effluent and intermediate was re- sampled on 07 July 2003 and did not detect any MTBE ' a Between 25 March 2003 and 25 June 2003,the mass of MTBE removed from the extracted ground water was calculated to be 0 74 pounds (Table 8, Appendix D) L • 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 E,during the second quarter 2003, MTBE concentrations have steadily declined to 17 gg/1 in June 2003 from a spike of 83 µg/1 in March 2003 ' The results from the ground water monitoring and sampling events performed in December 2002 are as follows • Generally,depth to ground water at the site vaned between 12 and 16 feet bsg,ground water elevations rangedbetween433feet(MW-lOCand MW-13D)and 5 27 feet(MW-1 8)below mean sea level (Table 4) ' Advanced GeoEnvironmental,Inc