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' 40 GROUNDWATER ANALYTICAL RESULTS • Groundwater laboratory analytical results are summarized in Table 1 In the Fourth Quarter 2003, approximately i/4-inch of free floating product was observed on the water surface in groundwater monitoring wells MW-1 and MW-3, no groundwater samples were collected due to the presence of ' free product The highest benzene, TPHg, and MTBE concentrations were detected in MW-2 at 91 micrograms per liter (ug/1), 180 ug/l, and 12 ug/l, respectively MTBE was also present in groundwater monitoring wells MW-4, MW-5, and MW-7 at concentrations ranging from 0 51 ug/I (MW-7) to 6 9 ug/1 (MW-4) Other FOCs were not detected above the laboratory reporting limits in samples collected from the groundwater monitoring wells except MW-2 where TBA (180 ug/1) and ETRE (12 ug/1)were detected Well AS-1, located within the source area and screened from 40 to 45 feet below ground surface (bgs) (deeper than the monitoring wells), was sampled for the fifth time ' since the startup of remedial activities The groundwater sample collected from AS-1 did not contain concentrations of TPHg, BTEX, or FOCs above the laboratory reporting limits (Table 1) Copies of the laboratory analytical reports and chain-of-custody documents for the groundwater samples wells ' are Included in Appendix C A decreasing contaminant trend in groundwater has been observed since the start of remediation in the Third Quarter 2002 (September 2002)through the Fourth Quarter 2003 (October 2003) MThere were no established trends for the analytical data for dissolved metal concentrations from wells MW-5, MW-513, MW-6, and MW-9(Table 2) The collected data will be compared with future dissolved metal concentrations in order to monitor the effects of ozone on dissolved metals in groundwater at the site Copies of the laboratory analytical reports and chain-of-custody documents for the groundwater samples collected from the groundwater monitoring wells are included in Appendix C ' The water samples collected from domestic wells DW-2R and DW-3 did not contain detectable concentrations of TPHg, BTEX or FOCs DW-1, sampled monthly, did not contain detectable concentrations of TPHg, BTEX, oxygenates, 1,2-DCA, or EDB Copies of the laboratory analytical reports and chain-of-custody documents for the water samples collected from the domestic wells are included in Appendix C Prol(a No 58643-06-01 -8- N0VL1nbLr 3 2003 1