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01 November 2004 AGE-NC Project No. 95-0137 Page 5 of 7 After installing the well casing in each pilot boring, a filter pack material consisting of pre-washed #3 Lonestar sand will be added through the augers over the screen interval to approximately two feet above the screened interval.Following placement of the filter pack,the well will be surged to assist in settling the filter pack. Additional sand will be added if settling occurs. A nominal two-foot bentonite seal(Pel Plug non-coated 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 them 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 within one foot of the ground surface with 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 tremie pipe. A grout inspection will be scheduled with EHD personnel. Following completion of the monitoring wells,well elevations and locati will be surveyed by a California-licensed surveyor relative to City of Stockton elevation benchmark. 3.3. WELL DEVELOPMENT Development of the proposed wells will consist of a combination of bailing with a stainless steel bailer 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 ground water evacuation(purging)with a Waterra bailing 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. 3.4. GROUNDWATER SAMPLING PROCEDURES Ground water sample collection will be performed in accordance with the EHD's Recommended Groundwater Sampling Guidelines, dated 15 February 1995. 3.4.1. Static Water Level Measurements Before purging and sampling during ground water monitoring events, static water level will be measured using an electric water level indicator. Water level data will be recorded to the nearest 0.01-foot from a reference point marked of the top of the PVC well casing.Before and after each use, Advanced GcoEnvironmental,Inc.