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12 March 2001 <br /> AGE-NC Project No 97-0333 <br /> Page 7 of 8 <br /> After installing the well casing in each bonng, a filter pack material will be slowly emplaced through <br /> the augers over the screen interval to approximately two feet above the screened intervals, filter pack <br /> material in the ground water extraction well will consist of a 50/50 blend of pre-washed small- <br /> grained aquarium gravel and#3 Lonestar sand, filter pack material in the ground water observation <br /> well will consist of pre-washed #3 Lonestar sand Following placement of the filter pack, the <br /> screened interval from each well will be surged for approximately 20 minutes utilizing a six-inch <br /> diameter surge block to assist in settling the filter pack Additional filter pack material will be added <br /> if settling occurs <br /> A nominal two-foot bentonite seal (bentonite chips) will be placed above the filter pack to minimize <br /> the potential for grout penetration into the screened section of the well The bentonite seal will be <br /> formed by pouring bentonite chips into the annulus and allowing the pellets to settle on the filter <br /> pack The bentonite pellets will be allowed to hydrate with tap water 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 UIl portland neat cement and not more than 6 gallons of water per 94- <br /> pound sack of cement The grout will be placed by pumping through tremmie pipe A grouting <br /> inspection will be scheduled with PHS-EHD personnel <br /> 43 WELL DEVELOPMENT <br /> Development of the proposed extraction and observation wells will consist of a combination of <br /> bailing with a two- or four-inch diameter PVC bailer to remove the mayor 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 ground water evacuation (purging)with a submersible pump to finish the removal of fine- <br /> grained sediment Developmental purging activities will be continued until field parameter (pH, <br /> electrical conductivity, and temperature) readings have stabilized and purged water is visually <br /> sediment-free <br /> 44 AQUIFER PUMP TEST <br /> A I2-hour aquifer pump test will be conducted at the site to induce a decline in static water level in <br /> the newly installed ground water extraction well (screened 15 to 35 feet bsg) Pressure transducers <br /> Ail] be deployed in wells EW-I, MW-2, MW-3 and the newly installed observation well to measure <br /> difference in ground water levels before well pumping versus time during well pumping A constant <br /> ground water pumping rate (approximately 4 gallons per minute) will be utilised from the ground <br /> water extraction well during the aquifer pump test to achieve optimum draw-down influence Results <br /> ofthe draw-down pilot test will be included in a report of findings and submitted to the, KIS-L}ID <br /> +rl r r -!t ­1 N3ri...,, or <br />