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0 • <br /> Following removal of the tank contents, all appurtenances will be removed and <br /> capped, except those necessary to purge the tank. The tank will be inerted by <br /> using at least 10 pounds of dry ice per 500 gallons of tank volume. Following <br /> introduction of the dry ice, the total area of all openings will be limited to 100 square <br /> inches. Remote venting of tank vapors, monitoring of tank atmosphere and other <br /> procedures associated with inerting of UST are provided in the QC Program of the <br /> GMP under Sections B4.3.6 (Tank Inerting Procedures). <br /> The UST will be excavated using a track-mounted excavator or a wheeled <br /> backhoe. The perimeter of the tank will be excavated in a manner that minimizes <br /> the area of excavation and limits the amount of potentially contaminated soil that <br /> may be mixed with uncontaminated soil. Soil from above, below and around the <br /> tank will be field screened and stored in separate uncontaminated and <br /> contaminated stockpiles. <br /> Field screening will include visual inspection and use of a photoionization detector <br /> (PID) for volatile organic compounds (VOCs). During excavation, soil that has a <br /> strong organic or chemical odor, is visibly stained, or displays a high reading <br /> (greater than 10 ppm) on the PID will be stockpiled separately. Final determination <br /> of contamination will be based on sample analysis. Additional details on tank <br /> excavation procedures are provided in the QC Program of the GMP. <br /> • The UST will be removed using a backhoe and placed on the ground. All loose dirt <br /> will be removed so that it will not be inadvertently lost during transport and to allow <br /> close inspection. The tank will be visually inspected for excessive corrosion or <br /> holes that would indicate a possible leak. If a leak is discovered, the COR will be <br /> immediately notified. After inspection, the tank will be loaded onto the truck for <br /> disposal. <br /> The UST and contents will be hauled by Erickson to Erickson's facility in Richmond <br /> for scrap, and the tank contents to Gibson Environmental in Redwood City for <br /> disposal. Wastes will be transported under manifests in accordance with federal, <br /> State, and local regulations. Operating permits for Erickson and Gibson are <br /> included in the GMP, at the end of Section D, Safety and Health Program, under <br /> Disposal Facilities. <br /> After the tank removal, if the soil is determined by the COR to be contaminated, an <br /> additional 2 feet of soil will be excavated below the invert of the tank. Three soil <br /> samples will be collected from the bottom of the tank and analyzed to determine if <br /> all contaminated soil has been removed. If contamination is still present, the COR <br /> will provide direction concerning further sampling and site remediation. <br /> Tank excavation will be backfilled with uncontaminated soil, pea gravel, and/or <br /> • <br /> imported clean fill, and compacted to the percent maximum density specified in the <br /> A-4 <br />