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15 January 2007 <br /> AGE-NC Project No. 99-0669 <br /> Page 7 of 10 <br /> in wells installed within HU4. <br /> After installing the well casing,filter pack material consisting of pre-washed 43 Lonestar sand will <br /> be added from the bottom of the borehole to approximately two feet above the screened interval. <br /> Following placement of the filter pack, the well will be surged utilizing a 2-inch well surge block <br /> to assist in settling the filter pack.Additional sand will be added if settling occurs. <br /> A three-foot bentonite seal(%-inch coated bentonite pellets)will be placed above the filter pack to <br /> minimize the potential for grout penetration into the screened section of the well.The bentonite seal <br /> will be formed by slowly pouring the bentonite pellets into the annulus and allowing them to settle <br /> on the filter pack. The bentonite pellets will be allowed to hydrate for a minimum of one-half hour <br /> prior to grouting. <br /> The remaining annular space will be filled to the ground surface with a cement grout. The grout <br /> mixture will consist of Type I/II portland neat cement and not more than 6 gallons of water per <br /> 94-pound sack of cement. The grout will be placed by pumping through tremie pipe. A grouting <br /> inspection will be scheduled with SJCEHD personnel.The proposed ground water well construction <br /> diagrams are depicted in:Figures 3 (HU2) and 4 (HU4). <br /> Upon grout completion, an eight-inch diameter, flush mount, traffic rated, steel well box will be <br /> installed over the well casings and secured with a bolted,steel well box cover.A reference point will <br /> be marked on the top of each well head, and surveyed by a California licensed surveying engineer <br /> to the nearest 0.01 foot to determine the elevation relative to a surveyed benchmark and to determine <br /> GPS coordinates for tracking on the State Water Resources Control Board (SWRCB) GeoTracker <br /> database system. <br /> 3.1.2. Well Development <br /> Development will consist of a combination of bailing to remove the major portion of fine-grained <br /> sediment from inside the well, surging to flush out or draw in sediment from the filter pack, and <br /> ground water pumping utilizing a two-stage submersible pump to finish the removal of sediment. <br /> Development activities will be continued until field parameter (pH, electrical conductivity, and <br /> temperature) readings have stabilized. <br /> 3.1.3. Ground Water Sampling Procedures <br /> Ground water sample collection will be performed in accordance with CVRWQCB and SJCEHD <br /> guidelines. <br /> Advanced GeoEnvironmental,Inc. <br />