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10 September 2012 AGE Project No . 11 -1847 Page 7of9 3 .2 , MONITORING WELL INSTALLATION AND SAMPLING Pilot borings for the wells will be advanced using a CME-75HT drill rig equipped with 8 .25- inch hollow-stem augers. Soil encountered in the pilot borings will be collected at five-foot intervals (beginning at 5 feet bsg ) using a California modified split-spoon samplerfitted with three 2-inch diameter, 6-inch long brass sleeves. Following sample collection , exposed ends of the selected sleeve will be labeled with boring location , depth , time , date and sampler's initials; appropriately sealed and labeled samples will be placed under ice in a chilled container and will be transported under chain- of-custody to a CDPH-certified laboratory for analysis of constituents listed in Section 2 .3 . Soil in the two remaining sleeves will be visually classified by AGE personnel in accordance with the USCS and field-screened for the presence of volatile organic compounds using an OVM equipped with a PID (Mini Rae 2000 [or equivalent] , calibrated to isobutylene ). 3 . 3 . WELL COMPLETION Following advancement of each pilot boring to total depth , the well casing , filter pack and sealing materials will be placed into the borehole through the interior of the hollow-stem augers . A 2-inch diameter, 20-foot Schedule 40 PVC blank casing and a 20-foot 0.020-inch slotted well screen will be installed in monitoring well boreholes . After installing the well casing , filter pack material consisting of pre-washed #3 sand will be added from the bottom of the borehole to approximately two feet above the screened interval . Following placement of the filter pack, the well will be surged to assist filter pack settling . Additional sand will be added if settling occurs . A nominal 2-foot bentonite seal 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 annular space between the hollow-stem augers and well casing and allowing them to settle on the filter pack. Bentonite pellets will be hydrated a minimum of 30 minutes or as specified by the manufacturer prior to grouting using five gallons of water. Remaining annular space above the bentonite seal will be filled to within one foot of the ground surface with a cement grout. The grout mixture will consist of Type 1111 portland neat cement and not more than 6 gallons of water per 94-pound sack of cement. Grout will be placed by pumping through tremie pipe . A traffic-rated well box will then be installed over the well casing . The SJCEHD will be notified for grout inspection at least 48 hours prior to conducting grouting procedures . Advanced CcoGnvironmentil, Inc.