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o'xygenates using EPA method 8260B, and for ethanol and methanol by method D285
<br /> The oxygenates that were analyzed are Di-isopropyl ether(DIPE), Ethyl tert-Butyl Ether(ETBE),
<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 oxygenate/alcohol results are summarized in Table 3 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 The
<br /> analytical laboratory results indicate that the highest groundwater concentrations of benzene was in
<br /> monitoring well TB-1, 515 ug/L, and the highest groundwater concentrations of TPH-g and MTBE
<br /> were in monitoring well MW-5 30,500 ug/L and 10,600 ug/L,respectively Other oxygenates were
<br /> below laboratory detection limits, except for a DIPE concentration of 4 4 ug/L (MW-2), and TBA
<br /> concentrations of 396 ug/L (MW-2), 100 ug/L (MW-3R), and 7,130 ug/L (MW-5) All alcohols
<br /> were below laboratory detection limits (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, T13-4, TB-6, and TB-9 (A,B)
<br /> During this reporting period, the soil vapor extraction unit(VEU) operated approximately 581 hours
<br /> and approximately 469 pounds of TPH-g were removed this quarter as of June 11, 2002 (Table 2
<br /> and Appendix Q The cumulative system total to date is approximately 15,583 hours of operation,
<br /> and approximately 63,410 pounds of TPH-g removed The system was shut down twice because of
<br /> the knockout switch and restarted on April 9 and May 14, 2002 The system was again shutdown
<br /> by Thrifty on June 11, 2002 because the blower needed to be replaced As to date,the system is still
<br /> waiting repairs
<br /> Vapor samples were collected from the system's inlet and outlet ports on April 18 and May 14,
<br /> 2002,and the inlet,outlet(ports), and selected site wells (Table 4) on May 14, 2002 (Figure 5) The
<br /> samples were analyzed for TPH-g by EPA method 8015M for gasoline, and BTEX/MTBE by EPA
<br /> method 8021B The effluent vapor laboratory results for May 14, 2002 indicated that TPH-g
<br /> concentration was 57 ug/L,benzene was 0 11,and MTBE was below the method detection limit The
<br /> remediation system's effluent air sample laboratory results are with the San Joaquin Valley Air
<br /> Pollution Control District's 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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