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1 27 December 2004 AGE-NC Project No. 04-1239 Page 6 of 8 with 2-inch diameter,6-inch long brass sleeves(five-foot sampling interval borings).Upon removal from the sampler,the sample sleeves will be separated with a knife.The exposed ends of the second sleeve will be covered with Teflon sheets,capped and sealed with tape. Soils sampled in the borings ' will be visually classified by an AGE geologist in accordance with the Unified Soil Classification System(USCS).Additionally,soil samples will be field screened for the presence of volatile organic compounds using an organic vapor meter(OVM),equipped with a photo ionization detector(PID). ' Soil sample descriptions and OVM readings will be recorded on a log for each boring. Following sample collection,each preserved sample sleeve will be labeled with the boring location, depth,time, date and sampler's initials. Appropriately sealed and labeled samples will be placed in a chilled container under ice and transported under chain-of-custody procedure to a DHS-certified laboratory. 1 ' 4.2. WELL COMPLETION AND WELL ELEVATION SURVEY If significant contamination is encountered, selected borings will be completed as 2-inch diameter ' ground water monitoring wells utilizing schedule 40 polyvinylchloride(PVC)0.01 0-inch slotted well screen and blank well casing. A 20-foot length of well screen is anticipated for installation of the monitoring well. A proposed monitoring well construction diagram is depicted in Figure 3. ' After installing the well casing in each pilot boring, a filter pack material consisting of pre-washed #2/12 Lonestar sand will be added through the augers, from the total boring depth 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 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 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 a cement grout. ' The grout mixture will consist of Type LE 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 tremmie pipe. A ' grouting inspection will be scheduled with SJCEHD personnel. Following completion of the monitoring wells,well elevations and locations will be surveyed by a ' California-licensed surveyor relative to a City of Stockton elevation benchmark. ' Advanced GeoEnvironmental,Inc.