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05 September 2002 <br /> AGE-NC Project No. 01-0887 <br /> Page 7 of 9 <br /> After installing the well casing, filter pack material consisting of pre-washed #2112 Lonestar sand <br /> willbe added from the bottom of the borehole to approximately one foot above the screened interval. <br /> Following placement of the filter pack, the well will be surged to assist in settling the filter pack. <br /> Additional sand will be added if settling occurs. <br /> A nominal one-foot thick bentonite seal will be placed above the filter pack to minimize the potential <br /> for grout to penetrate into the screened section of the well. The bentonite seal will be formed by <br /> pouring bentonite chips into the annulus and allowing them to settle on the filter pack. Bentonite <br /> chips will be hydrated using five gallons of water. The bentonite chips will be allowed to hydrate for <br /> a minimum of one.half hour prior to grouting. <br /> The remaining annular space will be filled to within a foot of the ground surface with a cement grout. <br /> The grout mixture will consist of type IVH portland neat cement and not more than 6 gallons of water <br /> per 94-pound sack of cement. The grout will be placed by pumping through a tremmie pipe. <br /> Grouting procedures will be inspected by EHD personnel. A traffic-rated well box will be installed <br /> over the well casing. A monitoring well design is illustrated in Figure 3. <br /> Following completion of the monitoring wells, well elevations and locations will be surveyed by a <br /> Califomia-licensed surveyor. <br /> 4.3. 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 /> additional bailing to finish the removal of sediment. Development activities will be continued until <br /> field parameter (pH, electrical conductivity, and temperature) readings have stabilized or until <br /> approximately 10 casing volumes of water have been purged from the well. <br /> 4.4. GROUNDWATER SAMPLING PROCEDURES <br /> Groundwater sample collection will be performed in accordance with CVRWQCB sampling <br /> protocols. Ground water sampling procedures are detailed below. <br /> Advanced GeoEnvironmentA Inc. <br />