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<br /> . Starting in the third quarter of 1997, as required by the Central Valley Regional Water Quality
<br /> Control Board(CVRWQCB), samples were also analyzed for selected oxygenates by EPA Method
<br /> 8260B,and alcohols by EPA method D285 (Glycols-Alcohols) The oxygenates and alcohols which
<br /> were analyzed are Di-isopropyl ether (DIPE), Ethanol, Ethyl tert-Butyl Ether (ETBE), Methanol,
<br /> Methyl tert-Butyl Ether (MTBE), Tert-Amyl Methyl Ether (TAME), and Tert-Butanol (TBA) A
<br /> summary of historical analytical sampling results for TPH-g, BTEX, and MTBE are provided in
<br /> Table 1, and oxygenates/alcohols results are summarized in Table 3 Copies of the EMC Field
<br /> Status Reports are presented in Appendix A, and copies of the laboratory analytical reports are
<br /> contained in Appendix B
<br /> The TPH-g, benzene, and MTBE isoconcentration maps are presented as Figures 2, 3, and 4 The
<br /> analytical laboratory results indicate that the highest groundwater concentrations of TPH-g,
<br /> benzene, and MTBE were in monitoring well MW-5 13,000 ug/L, 132 ug/L, and 23,200 ug/L,
<br /> respectively All other oxygenates (except MTBE) were below laboratory detection limits, except
<br /> for a TBA concentration of 173 ug/L in monitoring well MW-5 (Appendix B)
<br /> Remediation Status
<br /> On July 1, 1999, a Baker Furnace Thermal Oxidizer Unit was placed into operation with the hour
<br /> meter reading starting at 13,312 hours Presently,the remediation system is connected to soil vapor
<br /> extraction wells MW-2, MW-4, MW-5, TB-3, TB-4, TB-6, TB-7, TB-9 (A,B), TB-11 (A,B), and
<br /> TB-12 (A,B) A map showing the extraction well layout is shown as Figure 5 During this quarter
<br /> the only wells operating were TB-3, TB-4, TB-6, and TB-9 (A,B)
<br /> During this reporting period, the soil vapor extraction unit (VEU) operated approximately 1,044
<br /> hours and approximately 2,762 pounds of TPH-g were removed this quarter as of December 26,
<br /> 2001 (Table 2 and Appendix C) The cumulative system total to date is approximately 13,474 hours
<br /> of operation, and approximately 59,797 pounds of TPH-g removed The system was shut down for
<br /> quarterly water sampling on November 2 and restarted on November 9, 2001 The system was shut
<br /> down on September 25,2001 to replace the temperature controller, and restarted on October 9,2001
<br /> It was also down again on November 20 for motor replacement, and restarted after the new motor
<br /> was installed on November 23, 2001
<br /> Vapor samples were collected from the system inlet, outlet, and selected site wells (Figure 5) on
<br /> October 16,November 28, and December 13, 2001 A vapor inlet/outlet sample was inadvertently
<br /> not collected in November The samples were analyzed for TPH-g by EPA method 8015M for
<br /> gasoline, and BTEX/MTBE by EPA method 8021B The effluent vapor laboratory results for
<br /> October 16, 2001 indicated that benzene concentration was 0 10 ug/L and TPH-g, and MTBE
<br /> concentrations to be below the method detection limit The December 13 effluent bag sample was
<br /> deflated when it arrived at the laboratory for analysis, therefore the sample could not be analyzed
<br /> A copy of the vapor well-head laboratory analytical results, and copies of vapor inlet/outlet
<br /> . laboratory analytical results are presented in Appendix D A historical summary of hydrocarbons
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