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• • <br /> will be capped with a steel traffic box. See Figure 5. <br /> This well is positioned in order to assess the groundwater and <br /> soil east of wells BM-1 , BM-5 and boring B-1 . <br /> Core samples will be taken every 5 feet. Each core will be <br /> logged for stratigraphic information and tested with an Organic <br /> Vapor Analyzer (OVA) for gasoline in mg/kg. Selected cores will <br /> be placed on ice in a cooler and sent to Sherwood Labs, Hilmar, CA <br /> with a Chain of Custody. <br /> VAPOR WELL INSTALLATION <br /> Vapor wells to be used as vapor extraction points will be <br /> installed in each of the six (6) manholes previously placed on <br /> site and plumbed to a point near the northwest corner of the <br /> site. Figure 4 shows the location a piping to the manholes. <br /> Figure 6 shows the design of the vapor wells. A plot of the <br /> estimated soil contamination plume is shown in Figure 2 . In <br /> February, 1994 , an air permeability test was performed to find <br /> the radius of influence of the unsaturated zone. The test was <br /> reported in the Quarterly Report of May 12 , 1994 . The radius of <br /> influence was found to be about 25 feet. Figure 3 shows the <br /> radius of influence around each manhole. The interlocking <br /> circles appear to cover most of the contaminated zone on the <br /> site. <br /> All vapor wells will be drilled with a hollow stem auger. Core <br /> samples will be taken every 5 feet for stratigraphic information <br /> and will be tested with an OVA. Selected samples will be sent to <br /> Sherwood Labs, Hilmar, CA for analyses. <br /> The wells will be completed as described in the QA/QC protocols. <br /> Each well will be connected to the plumbed pipe located in the <br /> manhole. The connection will be checked for vacuum integrity. <br /> REMEDIATION <br /> The plumbed wells in the manholes will be connected to a manifold <br /> and then connected to a Thermal Oxidation System (TOS) which will <br /> extract vapor at the rate of 200 CFM. We will obtain an <br /> Authority to Construct to install the TOS. The TOS will be <br /> enclosed behind a chain link fence. A plot of the piping from <br /> the manholes to the treatment area is shown in Figure 4 . <br /> At start up, the system will be evaluated by applying a vacuum to <br /> each vapor well individually and taking reading from the <br /> surrounding wells. A report of showing the actual radius of <br /> influence of each well will be prepared and an addendum to this <br /> work plan will be presented. The addendum will address the work <br /> necessary to remediate the groundwater and soil across Grant <br /> • street from the site. <br /> Page 3 <br />