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12 August 2002 AGE-NC Project No. 99-0645 Page 6 of 8 Soil sample duplicates from the boring will be visually classified by an AGE geologist in accordance with the Unified Sol]Classification System(USCS). Additionally, soil samples will be field-screened for the presence of volatile organic compounds using an organic vapor meter equipped with a photo- ionization detector(PID: Thermo Environmental 580B, 10.0 eV, calibrated to isobutylene) The field data will be recorded on a Iog for the boring. 4.3. SOIL VAPOR WELL COMPLETION The pilot boring for the soil vapor extraction well will be advanced utilizing 8.25-inch augers. The boring will be advanced to 35 feet bsg for the shallow SVE wells and 70 feet bsg for the deep SVE wells, the proposed shallow soil vapor extraction well design is illustrated in Figure 4 and the deep soil vapor extraction well design is illustrated in Figure 5. Following completion of the 8.25-inch soil boring for the vapor extraction well, a 2-inch diameter Schedule 40 PVC 0.02-inch slotted well screen and casing will be installed;this well construction will allow for soil vapor production and extraction over the impacted zone, at separate levels. A 20-foot section of well screen will be installed from a depth of 15 feet to 35 feet bsg for shallow SVE wells and a 30-foot section of well screen will be installed from a depth of 40 feet to 70 feet bsg for deep SVE wells. This well screen will cover segregate the impacted lithologies, yet will allow for soil vapor extraction across the highest MTBE-impacted soil. The casing, filter pack and well sealing materials will be placed into the borehole through the interior of the hollow-stem augers. 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 one foot above the screened interval. A nominal one-foot bentonite seal will be placed above the filter pack. Bentonite chips will be hydrated be hydrated using five gallons of potable water. The remaining annular-spaces 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 10 gallons of water per 94-pound sack of cement. The grout will be placed by pumping through tremmie pipe. Grouting procedures will be inspected by PHS-EHD personnel. A traffic-rated well box will be installed over each well, in accordance with county regulations. 4.4. EQUIPMENT DECONTAMINATION All sampling tools used for sample collection will be thoroughly rinsed with clean water after being washed with a solution of Alconox. All down-hole drilling and sampling equipment will be pressure AdvancedCeoEnvironmental,Inc.