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11 July 2000 AGE-NC Project No 96-0232 Page 4of5 with 10 feet of 0 020-inch slotted well screen The proposed well construction diagrams are depicted in Figures 3 and 4 After installing the well casing in each boring, a filter pack consisting of pre-washed #3 Lonestar sand will be added through the augers over the screen interval to approximately two feet above the screened intervals in each well Following placement of the filter pack, the screened interval from each well will be surged for approximately 20 minutes utilizing a four-inch diameter surge block to assist in settling the filter pack Additional sand will be added if settling occurs A nominal two-foot bentonite seal (bentonite pellets) will be placed above the filter pack to minimize the potential for grout penetration into the screened section of the well The bentonite seal will be formed by pouring bentonite pellets into the annulus and allowing the pellets to settle on the filter pack The bentonite pellets will be allowed to hydrate for a minimum of one-half hour prior to grouting The remaining annular space will be filled to the ground surface with a cement grout The grout mixture will consist of Type I!II portland neat cement and not more than b gallons of water per 94- pound sack of cement The grout will be placed by pumping through tremmie pipe A grouting inspection will be scheduled with RWQCBIPHS-EHD personnel 33 WELL DEVELOPMENT Development of the proposed well will consist of a combination of bailing with a four-inch diameter PVC bailer to remove the mayor portion of fine-grained sediment from inside the well, surging to flush out or draw in sediment from the filter pack and additional ground water evacuation (purging) with a submersible pump to finish the removal of fine-grained sediment Developmental purging activities will be continued until field parameter (pH, electrical conductivity, and temperature) readings have stabilized and purged water is visually sediment-free 34 AQUIFER PUMP TEST A 24-hour aquifer pump test will be conducted at the site to induce a decline in static water level in the newly installed ground water extraction well (screened 10 to 35 feet bsg), prior to initiation of the pump test, ground water extraction from EW-1 will cease for approximately 12 hours to allow ground water level to stabilize Pressure transducers will be deployed in wells EW-1, MW-1 and the newly installed well screened 40 to 50 feet bsg to measure difference in ground water levels before well pumping versus time during well pumping A constant ground water pumping rate of . approximately 2 gallons per minute will be utilized from the ground water extraction well during the Advanced GeoEnwonmental,Inc