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KLEINFELDER Approximately 10 feet of the screened section will be placed below first encountered groundwater and 5 feet above first encountered groundwater. The wells will be finished with a locking pressure cap situated within a monument style (above ground) well vault. The bottom cap of the monitoring wells will be threaded, but if a threaded cap is not available, a slip cap secured with stainless steel screws will be used. To protect the PVC casing from the cement heat of hydration, especially in the deeper boring, 3% to 5% bentonite powder will be added, as approved in the San Joaquin County Well Standards. See the proposed Diagram of Well Construction (Plate 4). Note: The monitoring well screen length and slot size will be field assessed based on the lithologies encountered during advancement of the borings and adjusted to best suit the construction of the monitoring well. Well casing centralizers will be used to center the well casing in the deeper boreholes as needed. Once the monitoring wells have been installed, the top of each well will be surveyed by a State licensed land 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. 3.3 MONITORING WELL DEVELOPMENT A minimum of 48 hours after installation, the monitoring wells will be developed to remove fine silt from the well bore and to effectively increase the hydraulic radius of each monitoring well. Surging along the screened interval of the well will be performed to set the sand pack during installation and during the development stage. The monitoring wells will be developed as described in Appendix A Section A.3.2. In addition to developing the monitoring wells 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 in such a manner as not to allow the discharge to enter any surface water body. The drilling subcontractor will contact Underground Service Alert 48 hours prior to conducting fieldwork to notify local utilities of our proposed subsurface work. Kleinfelder will additionally prepare a health and safety plan prior to proceeding with field activities. 13498.WP2/3T02R534 Page 6 of 13 Copyright 2002,Kleinfelder,Inc. September 26,2002