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The groundwater samples were delivered to Sequoia Analytical and analyzed for TPH-g by Cal <br /> EPA-modified EPA Method 8015 and for BTEX by EPA Method 8020 Table 2 lists the <br /> analytical results for this quarter(in boldface type) and for all previous quarterly samplings <br /> TPH-g was detected in the samples collected from MW3, MWS, and MW7, at concentrations of <br />' 230,ug/L, 120µg/L, and 110 yg/L Unidentified hydrocarbons ranging from C6 to C8 were <br /> present on the gasoline sample chromatograms of all three wells Benzene was detected in the <br /> sample collected from MW3, at a concentration of 1 1 yg/L TPH-g and BTEX compounds were <br />' not detected in the samples collected from MW 1, MW2, MW4, or MW6 Analytical results are <br /> shown in Figure 1 Laboratory data sheets and chain-of-custody documentation are presented as <br /> Appendix B <br />' 3. REMEDIATION SYSTEM STATUS <br />' A soil vapor extraction system was installed at the site by a previous consultant (Fugro) and <br /> operated for approximately 5 months, from November 1995 to March 1996 Laboratory <br /> analytical results for samples of the extracted soil vapor (cumulative) collected by Fugro are <br />' listed in Table 3 <br /> A new soil vapor extraction (SVE) system has been installed by EA and was started upon <br />' inspection by the San Joaquin Valley Unified Air Pollution Control District on 21 February 1997 <br /> The system was shut down between 10 April 1997 and 25 April 1997 for carbon replacement <br /> Soil vapor is extracted out of only two wells (VEW1 and VEW2), because the screened intervals <br /> for the other three vapor extraction wells (MW2, MW3, and MW5) are completely submerged by <br /> the water table Laboratory analytical results for samples of the extracted soil vapor collected by <br /> EA are shown in Table 4 Influent concentrations and total pounds of hydrocarbons removed by <br /> the system are shown in Figure 2 <br />' 4. WORK PROPOSED FOR NEXT QUARTER <br /> The seven groundwater monitoring wells and two vapor extraction wells will be monitored for <br />' the presence of LPH The seven groundwater monitoring wells will be sampled, and the samples <br /> will be analyzed for TPH-g, BTEX, and methyl t-butyl ether <br />' The SVE system operation will continue during the following quarter and performance will be <br /> monitored and reported in the next quarterly report <br /> 1 <br />' WP61 70137 Q497 TX 2 2 <br />