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Iftow, 111.01 26 July 2002 AGE-NC Project No. 97-0326 Page 8 of 10 material will consist of pre-washed#2/12 Lapis Luster Monterey sand. Following placement of the filter pack, the screened interval from each well will be surged for approximately 20 minutes utilizing a surge block to assist in settling the filter pack. Additional filter pack material will be added if settling occurs. A nominal three-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 with tap water 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/Il portland neat cement and not more than 6 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 EHD personnel. 4.3. WELL DEVELOPMENT Single-level well development will consist of a combination of bailing to remove the major portion of fine-grained sediment from inside the well,surging to flush out or draw in sediment from the filter pack, and additional bailing to finish the removal of sediment. Development activities will be continued until field parameter (pH, electrical conductivity, and temperature) readings have stabilized or until approximately 10 casing volumes of water have been purged from the well. Well development will occur no sooner than 72-hours following well completion. Development of the proposed multi-level wells will consist of a combination of bailing and additional ground water evacuation (purging) with a 3/8-inch teflon tube bailer and Watera-Hydro- Lift 11 inertial pump to remove the major portion of fine-grained sediment from inside each well partition. Developmental purging activities will be continued until field parameter (pH, electrical conductivity, and temperature)readings have stabilized and purged water is visually sediment-free. 4.4. GROUND WATER MONITORING PROCEDURES Groundwater sample collection will be performed in accordance with EHD guidelines(San Joaquin County Public Health Services Environmental Health Division Well Standards)and the CVRWQCB guidelines (Tri-Regional Water Quality Control Board Recommendations for Preliminary Investigations and Evaluation of Underground Storage Tanks) sampling protocols. Advanced GeoEnviron mental,Inc.