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r r27 September 2004 • AGE-NC Project No 01-0827 rPage 4 of 5 r3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES Based on analysis of the 10 August 2004 ground water samples, TPH-g was detected in the ground r water samples collected from wells MW-6 and VW-2d at concentrations of 320 micrograms per liter (gg/1)and 1,400 gg/l,respectively Ethylbenzene and xylene were detected In the sample from well MW-6 at concentrations of 13 gg/1 and 12 gg/l, respectively BTEX compounds were detected in ' the ground water sample collected from well VW-2d at concentrations of 200gg/l benzene,22 gg/1 toluene,25 gg/l ethylbenzene and 32 Vg/1 xylenes MTBE and 1,2-DCA were the only fuel additives detected, in sample VW-2d at concentrations of 39 µg/1 and 6 4 gg/l, respectively(Tables 2 and 3) ' No other constituents were detected in the analyzed samples The analytical results are summarized In Tables 2 and 3 A copy of the laboratory reports (CTEL ' Project Nos CT214-0408081 and 0408 10 1)and chain of custody forms are Included In Appendix B GeoTracker confirmation pages of the submitted laboratory electronic deliverable format(EDF)files are Included in Appendix C I ' 4.0. SUMMARY AND CONCLUSIONS Based on the data collected from the site, AGE finds ' On 10 August, ground water was encountered at a depth of approximately 24 feet btoc, which is a decrease of approximately 0 87 feet since the June sampling event and a decrease ' of approximately 136 feet since the March sampling event The ground water flow direction was Inferred to be towards the southeast on-site, at a gradient of approximately 0 01 ft/ft on- site ' With the exception of wells VW-1 and VW-3, all wells are "drowned" and analytical data from these wells may not be representative of the shallow ground water conditions ' The maximum concentrations of TPH-g and BTEX compounds were detected in the ground water sample collected from deep vapor well VW-2d MTBE and 1,2-DCA were the only fuel additives detected, in sample VW-2d ' The concentrations of benzene, MTBE and 1,2-DCA in sample VW-2d were above the DHS's Primary Maximum Contaminant Levels (MCL) for drinking water • Low ORP values,detected In the source area,demonstrate the presence of generally reduced environment in the saturated zone near the source area Ideally, the Introduction of oxygen rich air (ozone air sparging) In the source area should produce an oxidizing environment ' which will lead to a reduction in contaminant levels Dissolved oxygen concentrations • collected from wells at the site, since operation of the ozone air sparge system commenced, rAdvanced GeoEnvironmental,Inc r