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oxygenates (di-isopropyl ether (DIPE), Ethyl tert-Butyl Ether (ETBE), Methyl tert-Butyl Ether
<br /> (MTBE), Tert-Amyl Methyl Ether (TAME), and Tert-Butanol (TBA)) using EPA method 8260B,
<br /> and for ethanol and methanol by ASTM method D285
<br /> A summary of historical analytical sampling results for TPH-g, BTEX, and MTBE is provided in
<br /> Table 1, and oxygenate/alcohol results are summarized in Table 2 Copies of the EMC Field Status
<br /> Reports are presented in Appendix A, and copies of the laboratory analytical reports are contained
<br /> in Appendix B
<br /> The TPH-g, benzene, and MTBE isoconcentration maps are presented as Figures 2, 3, and 4,
<br /> respectively The analytical laboratory results indicate that the highest groundwater concentrations
<br /> of TPH-g and MTBE were in monitoring well MW-5 (6,570 ug/L, and 14,100 ug/L, respectively)
<br /> Benzene concentrations were below the laboratory detection limits in all wells sampled The
<br /> selected oxygenate concentrations were below laboratory detection limits, except for DIPE and TBA
<br /> The DIPE concentrations were 3 6 ug/L, 1 5 ug/L, and 14 ug/L in wells MW-2, TB-1, and TB-7,
<br /> and the TBA concentrations were 95 ug/L, 1,150 ug/L, and 109 ug/L, in wells MW-2, MW-5, and
<br /> T13-1, respectively All alcohol concentrations were below laboratory detection limits (Appendix
<br /> B)
<br /> Reinediation Status
<br /> On July 1, 1999, a Baker Furnace Thermal Oxidizer Unit was placed into operation Presently,the
<br /> remediation system is connected to soil vapor extraction wells MW-2, MW-4, MW-5, T13-3, TB-4,
<br /> TB-6, TB-7, TB-9 (A, B), TB-11 (A, B), and TB-12 (A, B) A map presenting the extraction well
<br /> layout is shown as Figure 5 During this quarter the only wells operating were TB-3, TB-4, TB-6,
<br /> and T13-9 (A, B)
<br /> During this reporting period, the soil vapor extraction unit (VEU) operated approximately 1,484
<br /> hours and approximately 3,422 pounds of TPH-g were removed this quarter as of September 24,
<br /> 2002 (Table 3 and Appendix Q The cumulative system total to date is approximately 17,067 hours
<br /> of operation, and approximately 66,832 pounds of TPH-g removed The system was shut down by
<br /> Thrifty on June 11, 2002 because the blower needed to be replaced, and was restarted on July 16,
<br /> 2002
<br /> Vapor samples were collected from the system inlet and outlet ports on July 31, August 13, and
<br /> September 10, 2002, and the inlet, outlet (ports), and selected site wells (Table 4) on August 16,
<br /> 2002 (Figure 5) The samples were analyzed for TPH-g by EPA method 8015M for gasoline, and
<br /> BTEX by EPA method 8021B The effluent vapor laboratory results for September 10, 2002
<br /> indicated that TPH-g concentration was 23 ug/L, and benzene was 0 2 ug/L The effluent air sample
<br /> results are within the San Joaquin Valley Air Pollution Control District requirements
<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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