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Gealagkad Technics w Page 4 Site Closure Plan Project No.750.2 +r August 31,2005 * Remove well box * Cut the top of the well casing below grade a Fill the well casing with grout using a trimie pipe •- * Pressurize well casing as described above * Cement over the well casing making the surface flush with the median Category 2 Wells: These wells have been installed below grade and the top of casing does not reach the surface. The tops of casing are approximately 24-inches below the surface and are attached to horizontal vapor conveyance piping leading to a manifold system and the vapor extraction system located in a vault enclosure. GTI recommends the following abandonment procedure: * Remove the manifold and valves from the vault. * Feed 1-inch diameter poly tubing through the horizontal piping and down to the bottom of each extraction well. The poly tubing will act as a trimie pipe. * Pump grout slurry through the poly tubing into the extraction wells. * Pull back the poly tubing at ten-foot intervals, keeping the end of the tubing below the water column. * After the tubing is removed and the horizontal piping is full of grout, pressurize the grout �.. filled wells. * Approximately 35 psi of pressure will be applied to each well for up to five minutes. * After each extraction well is cemented in place, backfill the vault with clean soil and cap �- with appropriate material to match the surrounding surface conditions. Displaced water will be captured and placed into properly labeled DOT approved containers. �- The containers will be temporarily stored on-site until disposal can be arranged. Soil cuttings from the well abandonment activities will be stored in properly labeled DOT approved drums and temporarily stored on-site until disposal can be arranged. Approximately 48.6 cubic feet, or 363.3 gallons, of grout will be required for the decommissioning of the wells associated with the COE site. The calculations used to estimate the volume of grout are attached as Table 2 in Appendix A. 3.0 SCHEDULE & REPORTING Geological Technics Inc. anticipates beginning fieldwork no later than 45 days after work `' plan approval and issuance of the applicable permits. The information gathered during this phase of work will be presented in a report in an effort to meet the requirements of obtaining a "No Further Action Letter". Dr. Ray Kablanow, a registered professional geologist, will supervise the project. Copies of the report will be forwarded to both the appropriate County and State regulatory agencies (S3CEHD and CRWQCB).