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• 30 April 2005 AGE-NC Project No 96-0232 Page 5 of 9 2 4 2 Laboratory Results of Ground Water Samples During the March 2005 sampling event, TPH-g was not detected in any water samples TPH-d was detected in the water sample collected from well MW-12A at a concentration of 120 µg/1, the laboratory report noted that the TPH-d sample chromatogram had significant diesel range compounds The BTEX compound toluene was detected in sample MW-12A at a concentration of 9 9 pg/l (EPA Method 8020) MTBE was detected in water samples collected from wells MW-2,MW-4, MW-613, MW-7, MW- 8A, MW-11 (A and B), MW-13B, MW-14 through MW-18, MW-19A and MW-20 (A and B) at concentrations as high as 440 µg/1 (MW-20A), isoconcentration maps displaying the estimated extent of dissolved MTBE in First Zone and Second Zone aquifer are depicted in Figures 8, 9 and 10 TBA was detected in water samples collected from wells MW-2,MW-8A,MW-15 through MW-18, MW-19A and MW-20A at concentrations as high as 200 µg/l (MW-20A) No other constituents of concern were detected above laboratory reporting limits in the water . samples collected during the first quarter 2005 sampling event Analytical results of ground water monitoring well samples are summarized in Tables 3 and 4 The laboratory reports (McCampbell Analytical Inc Work Order Nos 0503501 and 0503532) and chain of custody forms are presented in Appendix C, GeoTracker confirmation pages of the submitted laboratory electronic deliverable format (EDF) files are included in Appendix D 3.0. SUMMARY OF FINDINGS FROM QUARTERLY ACTIVITIES Previous soil characteristics data obtained by a CPT investigation enabled AGE to define five informal hydrogeologic 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), 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 Between November 2000 and 17 August 2004, a total volume of 27,086,201 gallons of MTBE- impacted water was treated at the site utilizing pump-treat and carbon filtration remediation technology, due to the lack of cost effectiveness for the clean-up of MTBE-impacted ground water, pump-and-treat operations were suspended on 17 August 2004 • Advanced GeoEnvironmentai,Inc