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20 August 2018 <br />AdvancedGeo <br />AGE Project No. 13-2557 nvironmental <br />Page 5 of 6 <br />well casing. Well screens will be placed from 5 feet to 20 feet bsg and from 35 feet to <br />40 feet bsg. Proposed monitoring well construction designs are presented in Figures 7 <br />and 8. <br />After installing the well casings, a filter pack material consisting of pre-washed #3 sand <br />will be added through the augers to approximately one to two feet above the screened <br />interval. Following placement of the filter pack, the wells will be surged to assist in settling <br />of the filter pack. Additional sand will be added if settling occurs. <br />A nominal two-foot bentonite seal will be placed above the filter pack. The bentonite seal <br />will be formed by pouring bentonite chips into the annulus and allowing them to settle on <br />the filter pack; bentonite pellets will be used for the construction of the deep monitoring <br />well. The bentonite will be allowed to hydrate for a minimum of one-half hour prior to <br />completing the well. <br />The remaining annular space will be filled to the ground surface with a cement grout. The <br />grout mixture will consist of Type I/II Portland neat cement and not more than 6 gallons <br />of water per 94-pound sack of cement. A grouting inspection will be scheduled with <br />SJCEHD personnel. <br />Following completion of the monitoring wells, each well elevation and location will be <br />surveyed by a California-licensed surveyor relative to a benchmark as the North American <br />Vertical Datum 88. <br />3.3. MONITORING WELL DEVELOPMENT <br />Development of the proposed wells will consist of a combination of bailing with a stainless- <br />steel bailer to remove the major portion of fine-grained sediment from inside the well, <br />surging to flush out or draw in sediment from the filter pack, and additional groundwater <br />evacuation with a disposable plastic bailer or Waterra inertia pump to finish the removal <br />of fine-grained sediment. Developmental purging activities will be continued until field <br />parameters (pH, electrical conductivity, and temperature) have stabilized and purged <br />water is visually sediment-free. <br />3.4. GROUNDWATER SAMPLING PROCEDURES <br />Groundwater sample collection will be performed in accordance with AGE's standard <br />monitoring and sampling procedures, which have been included as Appendix C. <br />3.5. EQUIPMENT DECONTAMINATION/WASTE MANAGEMENT <br />All sampling tools will be thoroughly rinsed with clean water after being washed with a <br />solution of Alconox. All down-hole drilling equipment will be pressure washed prior to