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1 <br /> 06 November 2002 <br /> AGE-NC Project No 98-0432 <br />' Page 7 of 8 <br />' The grab ground water sample collected at 2,880 minutes ha TPH-g at 930µg/1 MTBE was <br /> detected at a concentration of 900 µg/1 by EPA Method 802q_and at a concentration of 1,100 <br /> µg/1 by EPA Method 8260 TBA, f 802q_and <br /> at concentrations as <br />' high as 80 µg/1 TAtnt Wks &4,d-(4J- 18aA�JL �, t,2--1)f A was Je�)z <br /> VM z/zol o 3 <br /> The analytical results of water samples are summarized in Table 2 The laboratory reports(CalTech <br />' Lab 1 D 0206-089-1 to 3), Quality Assurance and Quality Control data and chain-of-custody forms <br /> are presented in Appendix E <br /> 1 <br /> 5.0. SUMMARY AND CONCLUSIONS <br />' The ground water table occurred within the screened interval of the wells and the most likely source <br /> of the extracted ground water was from the highly permeable sand, encountered from 20 feet to <br />' 36 feet bsg <br /> The implications from the June 2002 aquifer ground water pumping tests are <br /> • Limited contamination to soil was detected in the are of well MW-9 MTBE was detected <br /> in soil at concentration as high as 0 54 mg/kg <br />' a During the constant-rate pumping test of June, ground water draw-down of at least 9 76 feet <br /> was observed in extraction well EW-1 following 24 hours of continuous pumping operation, <br />' ground water draw-down was observed in well MWA (20 feet away) at 0 4 feet ranging to <br /> 0 1 feet in well MW-7 (east) <br /> • Utilizing the Distance-Drawdown Method(Jacob straight-line method),a transmissivity was <br />' calculated at 1,000 ft'/day and a storativity of 0'17 <br /> • Based on transmissivity value of a hydraulic conductivity value was calculated at 0 175 cm/s <br />' is consistent with a screened interval located within a clean sand or gravel (Appendix G) <br /> • Low concentrations of MTBE and 1,2-DCA were removed during the extraction test Yui <br /> 6.0 RECOMMENDATIONS <br /> IBased on theground water aquifer pumping test results,AGE believes that a ground water recovery <br /> system can be developed to provide hydraulic control of the plume of dissolved fuel additive plume <br /> (MTBE,TAME, 1,2-DCA)and reduce the mass of MTBE,TAME, 1,2-DCA), as well as petroleum <br /> Advanced GcoEnvironmental,Inc <br /> I ' <br />