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were stored and transported in the cooler with the groundwater samples The samples were <br /> handled and transported under chain of custody <br /> The groundwater samples were delivered to Sequoia Analytical and analyzed for TPH-g by Cal <br /> EPA-modified EPA Method 8015, for BTEX by EPA Method 8020, and for MTBE by EPA <br /> Method 8020 For confirmation, the sample containing the highest concentration of MTBE was <br /> reanalyzed using EPA Method 8260 Table 2 lists the analytical results for this quarter (in <br />' boldface type) and for all previous quarterly samplings TPH-g was detected only in the samples <br /> collected from MW5 and MW7, at concentrations of 94 and 55 µg/L, respectively BTEX <br /> compounds were not detected in any of the samples MTBE was detected in the samples <br />' collected from wells MW3 and MW5, at concentrations of 4 7 tzg/L (MW3) and 4 5 yg/L <br /> (MW5) MTBE was detected at a concentration of 7 2 ,ug/L in the sample from MW3 using EPA <br /> Method 8260 Analytical results are shown in Figure 1 Laboratory data sheets and <br /> chain-of-custody documentation are presented as Appendix B <br /> 3. REMEDIATION SYSTEM STATUS <br /> An SVE system was installed at the site by a previous consultant (Fugro) and operated for <br /> approximately 5 months, from November 1995 to March 1996 Performance data collected by <br /> Fugro are presented in Table 3 <br /> A new soil vapor extraction (SVE) system was installed by EA and was started on 21 February <br /> 1997 Presently, soil vapor is extracted out of two wells (VEW 1 and VEW2), because the <br /> screened intervals for the other wells used for vapor extraction (MW2, MW3, and MW5) are <br />' submerged The system operated continuously during the entire fourth quarter Influent TPH-g <br /> concentrations and the estimated total pounds of hydrocarbons removed by the system are shown <br /> in Table 3 and on Figure 2 Laboratory analytical results for samples of the extracted soil vapor <br />' collected by EA are shown in Table 4 <br />' 4. WORK PROPOSED FOR NEXT QUARTER <br /> The seven groundwater monitoring wells and two vapor extraction wells will be monitored for the <br /> presence of LPH The seven groundwater monitoring wells will be sampled, and the samples will <br /> be analyzed for TPH-g, BTEX, and MTBE <br />' EA will continue to operate the SVE system in a "pulsed" mode, consisting of cycles of 2 weeks <br /> of non-operation followed by 1 week of operation during the following quarter, and performance <br /> will be monitored and reported in the next quarterly report If extracted soil vapor concentrations <br /> do not rebound during next quarter's pulsed mode operation, the remediation system will be shut <br /> down and closure proceedings will be initiated <br /> WP61 70137 Q1097 TX2 2 <br />