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13 August 2004 AGE-NC Project No. 95-0167 Page 6 of 9 3 .3 . MONITORING WELL PILOT BORINGS AND SOIL SAMPLING Soil borings will be advanced utilizing a truck-mounted, hollow-stem drill rig and 8-inch diameter hollow-stem augers. Cuttings and rinseate generated during drilling activities will be containerized in properly labeled DOT-approved 55-gallon drums, and stored on-site in an area lacking public access. Disposal alternatives will be evaluated based on results of soil and water analyses. Soil samples will be collected from each soil boring at five-foot intervals beginning at a depth of 5 feet bsg using a California modified split-spoon sampler fitted with three 2-inch diameter, 6-inch long brass sleeves. Following sample collection, the exposed ends of the leading or other selected sleeve will be labeled with the boring location, depth, time, date and sampler's initials; the appropriately sealed and labeled samples will be placed under ice in a chilled container and will be transported under chain of custody to a DHS-certified laboratory for analysis. The soil in the two remaining sleeves will be visually classified by an AGE geologist in accordance with the Unified Soil Classification System (USCS) and field-screened for the presence of volatile organic compounds using an organic vapor meter (OVM) equipped with a photo-ionization detector (PID : Thermo Environmental 580B, I O.OeV [or equivalent], calibrated to isobutylene). 3 .4. MONITORING WELL COMPLETION Following advancement of each first ground water pilot boring to total depth, a 2-inch diameter Schedule 40 polyvinyl chloride (PVC) 0. 020-inch slotted well screen and casing will be installed. A 15-foot section of well screen will be installed in each of the proposed shallow monitoring wells. The bottom of the screen interval will be placed approximately 10 feet below the water table. However, based on geologic/hydrogeologic conditions the screen length and placement may be modified with EHD approval. The well casing, filter pack and sealing materials will be placed into the borehole through the interior of the augers. After installing the well casing, filter pack material consisting of pre-washed silica 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 the potential for grout penetration into the screened section of the well. The bentonite seal will be formed by pouring bentonite chips into the annular space between the hammer casing and the well casing and allowing them to settle on the filter pack. Bentonite chips will be hydrated using at least five gallons Advanced GeoEnvironmental, Inc.