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S E C O R - - -- - 76(Former BP)Service Station 1193 SJCEHD November 15, 2007 Page 2 • Permitting. Permits for the installation and destruction of the groundwater monitoring wells will be obtained from SJCEHD prior to beginning work. • Borehole Clearance Activities. Prior to initiating field activities, SECOR will mark the boring location, contact Underground Service Alert (USA) at least 48 hours prior to the initiation of field work, and will contract a private utility locator to determine whether the proposed boring locations are clear of potential subsurface obstructions. After clearance is verified by USA and the utility locator, the borings will be air-knifed to a depth of approximately five feet below ground surface (bgs) to further minimize the risk of encountering subsurface structures that are not anticipated at the locations. • Well Destruction. SECOR will supervise a C57 California licensed drilling company during the destruction operations. The monitoring well M]V-12 located on the Kelly Drive(Figure 1)will be over drilled to its total depth removing the well casing, then grouted to ground surface using neat cement. The traffic rated well U l U boxes will be removed and the destroyed well will be capped with appropriate materials to match the existing grade. The well boxes and well casing will be contained and disposed of offsite. ? d • Well Installation. The borehole for well MW-13 will be completed as a two-inch diameter, Schedule 80 PVC groundwater monitoring well. The depth of the well and the length of the 0.010-inch slotted screen interval will be determined based on the depth of the next encountered water-bearing zone consisting of coarse- grained sediments, but is anticipated to be approximately 110 feet bgs, as described in the SECOR work plan dated August 30, 2007. For wells greater than 50 feet deep, stainless steel, collar-type centralizers will be attached to the well casing string, just above the top of the well screen and at every 50 feet of blank casing. In addition, straightness of the well casing string will be maintained by suspending the casing throughout the well construction process until the annular seal has set. • Compliance with AB 2886 Requirements. Also per AB 2886 requirements, SECOR will electronically upload the data obtained during this investigation into the SWRCB (State Water Resources Control Board) Geotracker Database (www.swrcb.aeotracker.ca.gov). Documentation of the electronic data format (EDF) submittals will be included in the final report. • Soil and Water Disposal. Soil cuttings and purgelrinsate water generated during well installation and destruction activities will temporarily be stored in California Department of Transportation(DOT)-approved, 55-gallon steel drums on-site pending characterization and disposal. The drums containing soil and IMP-ARCM05 BP-COP Sites1111931Work Plans111193 MW-12 Well Destruction WP.doc