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20 April 2007 <br /> AGE-NC Project No. 95-0167 <br /> Page 9 of 10 <br /> than 6 gallons of water per 94-pound sack of cement. The grout will be placed by pumping through <br /> a tremie pipe. The EHD will be notified for grout inspection at least 48 hours prior to conducting <br /> grouting procedures. An SVE well diagram is illustrated on Figure 6. <br /> 4.4. 1 . SVE Pilot Test <br /> An 8-hour SVE pilot test will be conducted at the site. The test will be conducted using a vapor <br /> extraction system, manufactured by AGE. This vapor extraction system consists of a regenerative <br /> blower driven by an 2 horsepower motor. Granular activated carbon (GAC; vapor phase) is proposed <br /> for the recovered hydrocarbon vapor by utilizing a regenerative blower-based soil vapor extraction <br /> system. The SVE unit used will be portable (trailer-mounted) due to the limited length of use <br /> proposed. The inlet of the system will be connected to one of the newly-installed SVE wells (well <br /> VW- I extraction well) . Air-tight well caps fitted with attached Magnehelic vacuum gauges will be <br /> attached to wells OBW4 , MW-5 and MW-7, and the induced vacuum will be measured at these <br /> monitoring points. The air stream from the extraction well will be monitored for the presence of <br /> organic vapor using an organic vapor analyzer (OVA) equipped with a PID. The vacuum applied to <br /> the extraction well will cause hydrocarbons in the soil to volatilize and flow through the vacuum <br /> pump to the GAC, where it will be adsorbed by GAC. <br /> 4.4.2 . Field Measurements <br /> During the vapor extraction pilot test, the air flow will be monitored using a Dwyer DS-200 flow <br /> sensor. Flow rates will be measured and documented in inches of water of differential pressure. The <br /> flow rate as standard cubic feet per minute (scfm) will be determined from the measured differential <br /> pressure and the piping diameter using a nomograph. Induced vacuum measurements will be <br /> recorded from the surrounding SVE wells utilizing Magnehelic gauges. The induced vacuum will <br /> be monitored for a stabilized value in inches of water during the pilot test. Hydrocarbon <br /> concentrations in the well effluent stream will be measured at regular intervals. A PID will be <br /> utilized for field measurements. <br /> 4.4. 3 . Collection and Analysis of Vapor Samples <br /> A total of four vapor samples will be collected at two-hour intervals from the inlet of the extraction <br /> well to measure concentrations of extracted hydrocarbon vapor. The samples will be collected in <br /> Tedlar bags using the organic vapor analyzer as an air pump. <br /> Following sample collection, the samples will be placed in a covered container and transported under <br /> chain of custody to a California Department of Health Services-certified analytical laboratory for <br /> Advanced GcoEnvironmcntal, Inc. <br />