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• 0 the percentage of bentonite in the bentonite-cement grout will not exceed 5 percent by volume, to prevent excessive shrinkage of the cement mix. 3. Well Protection Because the monitoring wells will be located within the land application area, where vegetation may limit visibility, it is proposed that they be constructed with above-ground completions. Above-ground completions will consist of an 8-inch protective casing installed at the well. This protective casing will extend approximately 2 feet above the ground surface and 3 feet into the well seal grout. The protective casing will be vented to the atmosphere by a lockable, hinged cap. The cap will prevent entry of water but will not be airtight, so the well will be in open connection to the atmosphere to allow for water level stabilization. The hinged cap will be locked with a heavy-duty padlock. The top of the well casing will be a minimum of 4 inches below the protective casing cap. In addition, a ''/4 inch diameter drainage port will be installed centered 1/8 inch above the level of the concrete pad. A square concrete pad will be placed at the monitoring well site, with the well located at the center of the pad. The pad will measure 3 feet by 3 feet, and will be 6 inches thick. The pad will contain welded wire fabric (No. 10 wire) at middle depth throughout. Four 4-inch diameter, Schedule 40 steel posts will be installed around the monitoring well pad to prevent damage to the well by vehicular operation. The posts will be installed a minimum of 2'/2 feet into the ground and extend approximately 3'/2 feet above ground surface. The posts will be anchored in concrete and painted fluorescent yellow or orange. The outside of the protective casing,hinges, and cover/cap will also be painted fluorescent yellow or orange. Extra care will be taken to ensure that no paint or aerosol spray enters the well. The well designation will be painted on the outside of the protective casing using white paint and a stencil. The identification will be accomplished after the casing is painted. All painting will be completed and dry prior to well development. The site will be restored at the completion of the well, with sites graded to original contours. D. WELL DEVELOPMENT The monitoring wells will be cleaned and developed to improve the permeability of the zone around the well screen, and to permit the collection of sediment-free groundwater samples. The development of the monitoring well will be performed as soon as practical after well installation, but no sooner than 48 consecutive hours after grout seal placement. Well development will be accomplished with a pump and/or a bottom discharge/filling bailer(for sediment removal) and surge block. Well development will be completed at least four consecutive days before well sampling. Development will proceed in the manner described below until the well water is clear to the unaided eye and the sediment thickness remaining within the well is less than 5 percent of the screen length. No dispersing agents, acids, disinfectants, or other additives will be used during development Project Workplan 5 SA1433 July 30,2004 n1sa01433\gwmwiwp\workp1an.doc