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17 January 2003 <br /> AGE-NC Project No. 02-0946 <br /> Page 8 of 9 <br /> After installing the well casing, filter pack material consisting of pre-washed #2/12 Lonestar sand <br /> will be added from the bottom of the borehole to approximately 2 feet above the screened interval. <br /> Following placement of the filter pack, the well will be surged to assist in settling the falter pack. <br /> Additional sand will be added if settling occurs. <br /> A nominal 2-foot thick bentonite sea] 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 Il11 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 4. <br /> Following completion of the monitoring wells, well elevations and locations will be surveyed by a <br /> California-licensed surveyor. <br /> 4.4. GROUND WATER MONITORING WELL DEVELOPMENT <br /> Development will consist of a combination of bailing to remove the major portion of tine-grained <br /> sediment from inside the wells, 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 of the purged ground water <br /> have stabilized. <br /> 4.5. GROUND WATER MONITORING AND SAMPLING <br /> Groundwater sample collection will be performed in accordance with pertinent applicable sampling <br /> protocols, details of which are presented below. <br /> 4.5.1. Static Water Level Measurements <br /> Before sampling, static water level will be measured in each well using an electric water level <br /> indicator. Water level data will be recorded to the nearest 0.01-foot from a reference point marked <br /> Advanced GcoEmironmental,Inc. <br />