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' 08 September 2005 . AGE-NC Project No 97-0333 ' Page 8ofII PCE was detected in forty-six out of forty-seven ground water samples analyzed at concentrations as high as 2,600 µg/l(MW-7C),TCE was detected in ground water samples MW-2,MW-3,MW-6, MW-7 (A-E), MW-8(B-D), MW-9B, MW-10(A-F), MW-11(C-D), MW-12 (A-D) and MW-13 ' (B-D) at concentrations as high as 430 µg11 (MW-10B) An iso-concentration map displaying the estimated extent of dissolved PCE in First Zone water is depicted on Figure 10 No other constituents of concern were detected above laboratory reporting limits in the ground water samples collected during the first quarter 2005 sampling event Analytical results of ground water monitoring well samples are summarized in Tables 5 and 6 GeoTracker confirmation pages of the submitted laboratory electronic deliverable format (EDF) files are included in Appendix B, the laboratory reports(CTEL Laboratory I D Nos 0504-009 and 0504-035), quality assurance/quality control (QA/QC)reports, and chain of custody forms are presented in Appendix F 4.0. SUMMARY AND CONCLUSIONS Previous soil characteristics data obtained b a CPT investigation enabled AGE to define four high Y g g permeability, informal hydrogeologic units (CPT Site Investigation - Fourth Quarter 2000, dated 07 February 2001) The informal hydrogeologic units were defined as First Zone (15-47 feet bsg), Second Zone, (58-92 feet bsg), Third Zone (102-120 feet bsg), and Primary Aquifer Zone (128-150 feet bsg), and are separated by less-permeable, fine-grained intervals I The results of pump and treat ground water remediation between 30 December 2004 and 15 March ' 2005 are as follows • Approximately 286,020 gallons of hydrocarbon-impacted ground water were extracted from well EW-1,which was completed in the First Zone aquifer A total volume of approximately 3,136,723 gallons of hydrocarbon-impacted ground water has been treated at the site since start-up in January 2002 (Table 1) • Dissolved MTBE was detected from grab samples collected at the influent end of the treatment system at concentrations between 380 µg/l and 2,200 µg11, laboratory analysis of grab water samples collected at the effluent end did not detect any constituents of concern during the first quarter 2005 (Table 2) • Between 30 December 2004 and 15 March 2005, an estimated 3 pounds of MTBE were extracted from ground water (Table 1, Appendix C), a total mass of 260 pounds of MTBE have been removed since initiation of the pump and treat system on 21 January 2002 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, although a slight MTBE increase was reported at the influent during the February 2005 monthly ' Advanced GeoEnvironmental,Inc