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'r 20 December 1998 <br /> AGE-NC Project No. 97-0312 <br /> Page 6 of 7 <br /> A nominal two to three-foot bentonite seal will be placed above the filter pack to minimize the <br /> potential of grout penetration into the screened section of the well. The bentonite seal will be formed <br /> by 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 20 minutes prior to grouting. The casing, filter pack and bentonite seal will be placed <br /> into the borehole through the interior of the hollow-stem augers. <br /> &W The remaining annular space will be filled to the ground surface with a portland cement grout. The <br /> grout will be placed by pumping through tremmie pipe for depths greater than 25 feet. Grouting <br /> procedures will be inspected by PHS-EHD personnel. <br /> LW <br /> Following completion of the monitoring well, the top of well casing will be notched and the <br /> elevation will be surveyed relative to the existing monitoring swells at the site. <br /> Ir 4.6. 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 /> ' produced water appears to be sediment-free. <br /> 4.7. GROUNDWATER SAMPLING PROCEDURES <br /> LV <br /> Ground water sample collection will be performed in accordance with sampling protocols presented <br /> below. <br /> a. <br /> 4.7.1. Monitoring Well Purge Procedures <br /> The static water level will be measured to the nearest 0.01 foot in each well relative to the top of the <br /> well casing using an electric water level indicator. Following depth to water measurement, the well <br /> will be purged using a bailer or submersible pump. A minimum of three casing volumes of water <br /> will be removed from the well. Ground water stabilization parameters (temperature, pH and <br /> conductivity) will be measured at regular intervals during purging. If a well is purged dry prior to <br /> evacuating three casing volumes, a ground water sample will be collected following 80 percent <br /> " recovery of ground water within the well or within 8-hours of well evacuation. <br /> a. <br /> Advanced GeciEnvirunmcntal,Inc. <br /> L <br />