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18 July 2002 AGE-NC Project No 95-0109 Page 6 of 8 1 For the well cluster in the area of boring CPT-3 • One boring with a 20-foot well screen installed from 50 feet bsg to 70 feet bsg, 1 • One boring with a 5-foot well screen installed from 75 feet bsg to 80 feet bsg, and • One boring with a 10-foot well screen installed from 110 feet bsg to 120 feet bsg The well casing,filter pack and sealing materials will be placed into the borehole through the interior of the hollow-stern augers After installing the well casing, filter pack material consisting of pre-washed#3/12 Lonestar 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 settling the filter pack Additional sand will be added if settling occurs A nominal two-foot thick bentonite seal will be placed above the filter pack to minimize grout penetration into the screened section of the well The bentonite seal will be formed by pouring bentonite chips or bentonite pellets into the annular space between the auger and the well casing and allowing the chips to settle on the filter pack The bentonite will be hydrated using five gallons of water The bentonite will be allowed to hydrate for a minimum of one-half hour prior to grouting The 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 I/II 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 tremae pipe The San Joaquin County Environmental Health Department (EHD) will be notified for grout inspection at least 48 hours prior to conducting grouting procedures Typical - monitoring well diagrams are illustrated on Figures 5 through 8 43 WELL DEVELOPMENT AND SURVEY Development will consist of a combination of bailing to remove the mayor 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 Purged ground water will be containerized in properly labeled DOT-approved model 17H 55-gallon drums and stored on-site Additionally, each well-head elevation and well location will be surveyed by a California-licensed surveyor relative to the closest San Joaquin County or City of Lodi benchmark Advanced GeoEnvironmental,Inc 1 ' f