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Date April 21,2004 <br /> Quarter 151 Quarter 2004 <br /> DISCUSSION <br /> Toluene, total xylenes, and methyl tert-butyl ether (MtBE) were reported in groundwater samples collected from site <br /> well this quarter MtBE concentrations in MW-5 were reported at the lowest levels historically In MW-11, toluene <br /> and total xylenes were reported below method detection lirmts this quarter Other analyte concentrations were <br /> generally consistent with the previous quarter <br /> Ethanol was reported above method detection hunts in site wells MW-9 and MW-10 at 770 and 500 micrograms per <br /> liter (µg11.,), respectively After receiving the results,MW-9 and MW-10 were resampled to confirm the presence of <br /> ethanol on March 11, 2004 Ethanol was reported as below method detection limits in both the MW-9 and MW-10 <br /> confirmation samples A regulator from the San Joaquin County Environmental Health Department(SJCEHD) was <br /> onsite during the confirmation sampling and noticed a black, oily substance on the inside of the MW-9 well casing <br /> As requested by the regulator, the interior of the casing was cleaned and the well redeveloped on March 16, 2004 <br /> The well development log for MW-9 is included in Appendix B <br /> Groundwater elevations slightly decreased relative to the previous quarter The inferred direction of groundwater <br /> flow ranged from the northeast to northwest at an average hydraulic gradient of 0 009 to 0 016 feet/foot, which is <br /> consistent with historic data <br /> This report is based on data, site conditions,and other information that are generally applicable as of the date of the <br /> report,and the conclusions and recommendations herein are therefore applicable only to that time frame <br /> TABLES <br />. Table 1 Groundwater Elevation and Analytical Data <br /> Table 2 Fuel Oxygenates Analytical Data <br /> Table 3 Groundwater Gradient Data <br /> FIGURES <br /> Figure 1 Groundwater Elevation Contours <br /> Figure 2 Groundwater Analytical Summary <br /> APPENDICES <br /> Appendix A Field and Laboratory Procedures <br /> Appendix B Laboratory Analytical Reports,Cham-of-Custody Documentation,and Field Data Sheets <br /> Appendix C GeoTracker Upload Confirmation <br /> K 1WPmcess115 BP ARC01060205Quan.r1yk1 QTR 0416020 GWMR IQ04&c Page 2 <br />