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31 October 2007 <br /> AGE-NC Project No. 07-1524 <br /> Page 8 of 10 <br /> well. A proposed monitoring well construction diagram is depicted in Figure 3. <br /> After installing the well casing in each pilot boring, a filter pack material consisting of pre-washed <br /> 42/12 Lonestar sand will be added through the augers over the screen interval to approximately two <br /> feet above the screened interval. Following placement of the filter pack. the well will be surged to <br /> assist in settling the filter pack. Additional sand will be added if settling occurs. <br /> A two-foot bentonite seal (bentonite chips) will be placed above the filter pack to minimize the <br /> 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 them to settle on the filter pack. <br /> The bentonite pellets will be allowed to hydrate for a minimum of one-half hour prior to grouting. <br /> The remaining annular space will be filled to within 1 foot of the ground surface with a cement <br /> grout. The grout mixture will consist of Type I/1I portland neat cement and not more than 6 gallons <br /> of water per 94-pound sack of cement. The grout will be placed by pumping through a tremie pipe. <br /> A grouting inspection will be scheduled with EHD personnel. <br /> Following completion of the monitoring wells, well elevations and locations will be surveyed by a <br /> California-licensed surveyor relative to a City of Stockton elevation benchmark. <br /> 4.4. WELL DEVELOPMENT <br /> Development of the proposed wells will consist of a combination of bailing with a stainless steel <br /> bailer to remove the major portion of fine-grained sediment from inside the well, surging to flush <br /> out or draw in sediment from the filter pack and additional ground water evacuation (purging) with <br /> a Waterra bailing pump to finish the removal of fine-grained sediment. Developmental purging <br /> activities will be continued until field parameter (pH, electrical conductivity, and temperature) <br /> readings have stabilized and purged water is visually sediment-free. <br /> 4.5. GROUNDWATER SAMPLING PROCEDURES <br /> Ground water sample collection will be performed in accordance with the CVRWQCB guidelines <br /> and general industry standards. <br /> 4.5.1. Static Water level Measurements <br /> Before purging and sampling during ground water monitoring events, static water level will be <br /> Advanced Geo Environmental,Inc. <br />