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ATC Associates Inc. <br /> YVAtC <br /> 1117 Lone Palm Avenue, Suite 201 <br /> Modesto,California 95351 <br /> 209-579-2221 <br /> ASS O C I ATE s i N c . Fax:209-579-2225 <br /> pounds of total petroleum hydrocarbons as gasoline (TPHg), including an estimated 823.39 <br /> pounds of benzene, toluene, ethyl benzene, and total xylenes (BTEX) constituents. Using an <br /> average density of gasoline of 6.25 pounds per gallon, this represents removal of the equivalent <br /> of approximately 1,000 gallons of gasoline. <br /> SCOPE OF WORK <br /> Well Destruction <br /> On August 3 through 5, 2011, ATC supervised the destruction of monitoring wells MW1 through <br /> MW7, vapor extraction wells VEW1 through VEW3, and four soil vapor points, SG1 through <br /> SG4. Wells MW1 through MW7 were constructed with 2 inch diameter PVC inside an 8 inch <br /> borehole and set at a depth of 65 feet bgs. The vapor extraction wells were constructed with 2 <br /> inch diameter PVC inside an 8 inch borehole and set at a depth of 35 feet bgs at VEW1 and 45 <br /> feet bgs at VEW2 and VEW3. The well abandonment was conducted by Precision Sampling, <br /> State C57 License No. 636387. Neat cement grout was pumped into each well via tremie, until <br /> the pipe was completely filled. At each well a minimum of 25 psi of pressure was applied for a <br /> minimum of five minutes. An annular space of 24 inches was excavated around each well to a <br /> depth of 3 feet bgs. The wells were then backfilled with additional grout until the excavation <br /> was filled to a minimum of one foot above the top of the PVC pipe. The remaining excavation <br /> was backfilled with native soil and a concrete cap was installed. <br /> Investigative Derived Waste <br /> Soils generated by the abandonment of the monitoring wells were stored in Department of <br /> Transportation approved drums. The soil generated during the well abandonment activities was <br /> tested by a state certified laboratory and the results indicate that no chemicals of concern were <br /> detected above the laboratory detection limits. Lead was detected at 6.6 mg/kg. The laboratory <br /> report is included in Attachment 1. The waste drums were removed from the site and were <br /> properly disposed of. Manifests for these drums are included in Attachment 2. <br /> REMEDIATION SYSTEM DECOMMISSIONING <br /> The remediation system is currently being decommissioned. <br /> These actions complete the requirements of the CVRWQCB and the SJCEHD to close the site. <br /> S:Tnviromental162577-Diesel Perf1REPORTS1WP-Well Abandonment 3 <br />