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18 November 1999 AGE-NC Project No. 97-0327 Page 7 of 9 logs.Upon soil sample retrieval,the middle brass sleeve will be removed from the sampler. The ends of the brass sleeve will be immediately covered with Teflon or aluminum sheets, sealed with plastic end caps, secured with tape and immediately placed in a chilled container for transponation under chain of custody to a state-certified laboratory. Each sample sleeve will be labeled with the boring location, sample depth, sample time, sampling date and sampler's initials. During sampling activities, sample duplicates will be monitored for the presence of organic vapor using a photo-ionization detector (PID: Thermo Environmental 580A, 10.0 eV, calibrated to isobutylene) and will be visually described on boring logs using the Unified Soil Classification System (USCS). All sampling tools and brass sleeves used for sample collection will be thoroughly rinsed with clean water after washing with a solution of Alconox. All hollow stein augers will be steam-cleaned prior to advancement in each borehole. 4.3. WELL COMPLETION _ Soil borings will be single-completed as ground water monitoring wells utilizing 2-inch diameter schedule 40 polyvinylchloride (PVC) 0.020-inch slotted well screen and blank well casing. Based on geologic,ihydrogeologic conditions, a 20-foot length of well screen is anticipated for installation of monitoring wells; the bottom of the screen interval will be placed 15 feet below the water table. A proposed well construction diagram is depicted in Figure 4. After installing the well casing, filter pack material consisting of pre-washed #3 Lonestar sand will be added from the bottom of the borehole to approximately two feet above the screened intcrval. Following placement of the filter pack, the well will be surged with a 2-inch diameter well block to assist in settling the filter pack. Additional sand will be added if settling occurs. A nominal two-foot bentonite seal (bentonite chips) 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 annulus and allowing them to settle on the filter pack. Bentonite chips will be hydrated using approximately five gallons of tap water. The bentonite chips will be allowed to hydrate for a minimum of one-half hour prior to grouting. The remaining annular space will be filled to 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. The grout will be emplaced utilizing tremie pipe. A grouting inspection will - be scheduled with PHS-EHD personnel. Advanced GeoEnvironmental.Inc.