ARCHIVED REPORTS XR0003442 - Laserfiche WebLink

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Ms Marla D Guenslcr Exxon Company, U S A August 20, 1997 Page 4 summarized in Table 2, and a copy of the laboratory analytical report for the May 30, 1997, sampling event is presented in Enclosure E SVE Pilot Testing Procedure Due to additional soil excavation activities that occurred after an initial SVE test was conducted (March 3, 1995), a second SVE test was performed to re-evaluate remedial options for the site Results of the first SVE test are included in a Delta report dated Apnl 12, 1995 On June 5, 1997, a SVE test was conducted on each of two vapor extraction wells (VEW-I and VEW-3) VEW-2 was not used since it had been destroyed during the additional soil excavation activities The first three hour test was conducted on VEW-3 and the second three hour test was conducted on VEW-1 A vacuum was induced in each of the test wells using a portable blower To reduce hydrocarbon emissions, the blower exhaust was routed through two 200-pound vapor phase granular activated carbon (GAC) columns prior to atmospheric discharge Field measurements collected during the tests included wellhead vacuum in VEW-1, VEW-3, and MW-1 through MW-3, soil vapor concentrations, airflow velocities, temperatures, lower explosive limit (LEL) values, oxygen content, and depth to ground water in the test wells Field monitoring data for the individual SVE tests are included in Enclosure F To assess the radial vacuum influence from the test conducted on VEW-3, vacuum measurements were recorded in VEW-I, MW-2, and MW-3 which are located approximately 45, 100, and 38 feet from VEW-3, respectively To assess radial vacuum influence from the test conducted on VEW-1, vacuum measurements were recorded in VEW-3, MW-1, and MW-2 which are located approximately 45, 25, and 95 feet from VEW-2, respectively GAC influent and effluent TPPH as hexane concentrations were monitored on an hourly basis with the use of a portable flame ionization detector (FID) with a methane filter In an effort to confirm FID measurements, vapor samples were collected in tedlar bags during each SVE test for laboratory analyses of BTEX and TPPH as gasoline using EPA Methods 8020 and 8015 Modified, respectively Influent samples were collected at the beginning and the end of each test period Effluent samples were collected at the start of the first test and the end of the second test SVE Pilot Testing Results Filtered FID measurements of TPPH concentrations ranged from 3 5 to 0 4 parts per million by volume (ppmv) during the test conducted on VEW-3 During the second test conducted on VEW-1, the filtered FID measurements ranged from 590 to 150 ppmv Field monitoring data is included in Enclosure F Analytical results from influent samples collected during the beginning and end of the test on VEW-3 as well as both effluent samples for the entire test did not report BTEX and TPPH as gasoline concentrations above the laboratory's Iimits of detection Analytical results from influent samples collected during the SVE test conducted on VEW-1 reported TPPH as gasoline concentrations that . ranged from 93 to 73 ppmv, with a calculated average of 83 ppmv Benzene concentrations for both influent samples collected during the second test conducted on VEW-1 were reported below the laboratory's limits of detection (<0 16 ppmv) Analytical results are presented in Table 7 A copy of the analytical reports is included in Enclosure G