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S ECOR <br /> Mr. Mike Infurna <br /> June 18, 2003 <br /> Page 2 <br /> WELL ABANDONMENT— PROCEDURES AND METHODS <br /> SECOR proposes abandoning the five 2-inch-diameter groundwater monitoring wells by overdrilling <br /> the borings with 8-inch hollow-stem augers. All well construction materials will be removed and the <br /> borings will be backfilled with bentonite slurry, topped with coarse aggregate, and finished to match <br /> existing grade. All waste generated will be disposed of appropriately. Specific methods and <br /> procedures are outlined in detail below. <br /> Preliminary Activities <br /> SECOR has submitted a completed Well Permit Application Form with the appropriate fee to the <br /> SJCEHD. Prior to initiating field activities, SECOR will prepare a site-specific health and safety plan <br /> to address potential hazards associated with well abandonment activities. A copy of the health and <br /> safety plan will be kept onsite during all field activities, and will be made available to all SECOR and <br /> subcontractor staff. SECOR will mark the work area in white paint, and notify Underground Service <br /> Alert at least 48 hours before well destruction activities. <br /> Groundwater Monitoring Well Abandonment <br /> The five groundwater monitoring wells will be abandoned by overdrilling the wells with 8-inch- <br /> diameter hollow-stem augers. Each well will be overdrilled to a depth of approximately one foot <br /> deeper than that of the completed well. The overdrilling method ensures that all well construction <br /> materials including the polyvinyl chloride well casing, the annular sandpack, the bendonite/grout <br /> sanitary seal and the wellhead vault box are removed. <br /> As the augers are removed, the borehole will be backfilled with bentonite slurry in accordance with <br /> state and local guidelines. The boreholes will be backfilled to approximately 2 feet below grade, and <br /> the bentonite will be allowed to expand and set up for the appropriate amount of time. The remaining <br /> space will be filled with approximately 20 inches of coarse aggregate or similar material, compacted, <br /> and finished to match the existing surface (asphalt or surrounding soil). This method of bentonite <br /> slurry, followed by compacted aggregate and final finishing material, is intended to minimize or <br /> eliminate future upheaval of the column of slurry. <br /> Waste Management <br /> Waste materials generated during overdrilling will be placed in steel 55-gallon drums, labeled as to <br /> contents, and left onsite pending profiling and proper disposal. SECOR estimates generating <br /> approximately five drums of soil cuttings during monitoring well abandonment. SECOR will contract <br /> with Integrated Wastestream Management of Milpitas, California to collect and dispose of the waste <br /> within ten business days of the end of field activities. <br /> Reporting <br /> Following well abandonment activities, SECOR will prepare a summary report for submission to the <br /> SJCEHD and the RWQCB. The report will contain a summary of field activities, a scaled site plan <br /> showing the locations of the former monitoring wells, a copy of the well destruction permit, and <br /> copies of pertinent correspondence between SECOR and SJCEHD and RWQCB staff. <br /> Well Destruction WP SECOP International Incorporated <br />