|
i
<br /> Thrifty Oil Co. Station #172
<br /> • Page2
<br /> ITPH-g, BTEX, and MTBE concentrations appear in Table 1, while historical oxygenate and alcohol
<br /> results are presented in Table 2 Copies of groundwater laboratory reports and chain-of-custody
<br /> I documents are included in Appendix B The TPH-g, benzene, and MTBE isoconcentration maps
<br /> are presented as Figures 2,3, and 4. The highest concentrations of TPH-g, benzene, and MTBE in
<br /> groundwater were found in monitoring well MW-11 (127,000 ug/L, 18,300 ug/L, and 786 ug/L,
<br /> Irespectively)
<br /> Since the third quarter of 1997,Thrifty has analyzed for the requested oxygenates di-isopropyl ether
<br /> (DIPE), ethyl-tert butyl ether(ETBE), tert-amyl methyl ether(TAME), and tert-butanol (TBA), and
<br /> MTBE by method 8260B The following alcohols were also requested for analysis ethanol and
<br /> I methanol Laboratory results indicate no alcohols or oxygenates were detected above the laboratory
<br /> detection limit
<br /> IRemediation Status
<br /> Vapor Extraction system
<br /> IOn April 26, 2001, a new Baker Furnace Thermal Oxidizer Unit was placed into operation with the
<br /> hour meter reading at zero Presently,the remediation system is connected to soil vapor extraction
<br /> I ! wells (VW-1, VW-2 (A,B), VW-3, VW-4 (A,B,C), VW-5 (A,B,C), and VW-6(A,B,C)) The only
<br /> I wells operating throughout the quarter were VW-2A, VW-213, VW-3, and VW-5C Selected wells
<br /> that operated intermittently throughout the quarter were VW4A, VW4C, VWSA, VWSB, VW-613
<br /> Iand VW-6C During the second quarter of 2002, the soil vapor extraction unit (VEU) operated
<br /> approximately 1,550 hours for a total of 8,854 hours Approximately 1,752 pounds of hydrocarbons
<br /> I were removed during the second quarter 2002 for a total of 30,401 pounds as of June 27, 2002
<br /> (Table 3)
<br /> Influent and effluent vapor samples were collected on April 18, May 30, and June 20, 2002 In
<br /> addition, samples were collected on May 30, 2002 from selected well-heads The well-head,
<br /> influent, and effluent vapor samples were analyzed for TPH-g by EPA method 8015, and
<br /> I BTEX/MTBE by EPA method 8021B A copy of the influent, effluent, and well-head vapor sample
<br /> laboratory analytical results are presented in Appendix D
<br /> I A historical summary of hydrocarbons removed by vapor extraction is presented in Table 3 The
<br /> Field Status Reports are included in Appendix C
<br /> IGroundwater Treatment System
<br /> The groundwater treatment system was started in conjunction with the vapor treatment system on
<br /> IApril 26, 2001, and the flow meter started at zero Presently, the remediation system is connected
<br /> to groundwater wells MW-10 and MW-11 Two down-well pneumatic pumps (one in each well),
<br /> f
<br /> I
<br />
|