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III KLEINFELDER Following completion of the drilling, a 2-inch diameter PVC well will be installed in the boring. The soil boring will be advanced approximately 10 feet into groundwater. The well will be constructed with Schedule 40 PVC using a 15 foot long 0.020 inch slot screened section. Approximately 10-feet of the screen section will be placed below estimated first encountered groundwater and 5-feet of screen section above first groundwater. The well will be constructed utilizing a sand filter pack (#2/12), 3 foot thick bentonite transition seal above the filter pack, and grouted to the surface with a neat cement mixed with no more than 3% to 5% bentonite powder to retard the heat of hydration and limit the possibility of damaging the PVC casing. The sand filter pack, bentonite seal material, and gout shall be installed via tremmie pipe, in accordance with San Joaquin County Well Standards. The wells will be finished with a locking pressure cap situated within a monument well vault. See the proposed Diagram of Well Construction (Plate 3). Once the monitoring well has been installed, the top of the well will be surveyed (by a licensed surveyor) so that depth to groundwater measurements in the wells can be converted to groundwater elevations used to assess groundwater gradients. The wells will be surveyed relative to a local benchmark. If a local benchmark is not available near the site, the wells will be surveyed relative to an onsite, assumed benchmark with an assigned elevation. The wells will be surveyed as described in Appendix A Section A-3.4. 3.4 MONITORING WELL DEVELOPMENT A minimum of 48 hours after installation, the monitoring well will be developed to remove fine silt from the well bore and to effectively increase the hydraulic radius of the monitoring well. Surging along the screened interval of the well will be performed to set the sand pack. The monitoring well will be developed as described in Appendix A Section A.3.2. In addition to developing the monitoring well until the discharge runs relatively clear of fines, the discharge will be periodically monitored for pH, temperature, and specific conductance. The well development purge water will be discharged to the land surface and will not be allowed to flow off the site. 3.5 REPORTING Upon completion of the abandonment and the installation of the replacement monitoring well a report of abandonment of MW-1 and installation of MW-lr will be prepared for client and agency review. The report will include: A description of field activities, observations, and protocols. Field logs for each well documenting lithology, depth to groundwater, parameters measured before, during, and after development, method of development, and total volume of water purged. A scaled map showing relevant structures and features of the facility, the locations of the monitoring wells. 24134.E01 / STO3R304 Page 5 of 10 Copyright 2003, Kleinfelder, Inc. February 26, 2003