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l <br /> 18 June 2010 <br /> AGE-NC Project No. 95-0135 <br /> Page 5 of 7 <br /> Soil encountered in the borings will be visually classified by an AGE geologist or environmental <br /> specialist in accordance with the Unified Soil Classification System (USCS)..Additionally, soil <br /> samples will be field-screened for the presence of volatile organic compounds using an organic vapor <br /> meter (OVM) equipped with a photo-ionization device (PID). Soil sample descriptions and OVM <br /> readings will be recorded on a log for each boring. Following sample collection, each preserved <br /> sample sleeve will be labeled with the boring location, depth, time, date and sampler's initials. <br /> Appropriately sealed and labeled samples will be placed in a chilled container with ice and <br /> transported under chain-of-custody procedure to a CDPH-certified laboratory. The proposed well <br /> locations are illustrated in Figure 2. <br /> 4.2. MONITORING WELL COMPLETION <br /> Soil borings will be single-completed as ground water monitoring wells utilizing 2-inch diameter <br /> schedule 40 polyvinylchloride (PVC) 0.020-inch slotted well screen and blank well casing. Well_ <br /> screens will be placed from 60 feet to 65 feet bsg(HU2 soil borings)and from 110 feet to 120 feet <br />{ bsg(HU3 soil boring). Proposed monitoring well construction diagrams are presented in Figures 3 <br /> and 4. <br /> After installing the well casings, a filter pack material consisting of pre-washed.#3 'sand will be <br /> added through the augers to approximately one two tw .feet above the screened interval. Following <br /> placement of the filter pack, the well will be surged to assist in settling the filter pack. Additional <br /> sand will be added if settling occurs. <br /> ,� 3,�Fo " <br /> A nominal two-foot bentonite seal will be placed above the filter pack. The bentonite seal will be <br /> formed by pouring bentonite pellets into the annulus and allowing them to settle on the filter pack. <br /> The bentonite will be allowed to hydrate for a minimum of one-half hour prior to completing the <br /> well. <br /> The remaining annular space will be filled to the:ground surface with a cement grout. The grout <br /> I <br /> mixture will consist of Type 1/Il portland neat cement and not more than 6 gallons of water per <br /> 94-pound sack of cement. A grouting inspection will be scheduled with EHD personnel. T <br /> 4.3. WELL DEVELOPMENT AND SURVEY <br /> Development of the proposed wells will consist of a combination of bailing with a stainless steel <br /> bailer to remove the major portion of fine-grained sediment from inside the well, surging to flush <br /> out or draw in sediment from the filter pack,,and additional groundwater evacuation(purging)-with <br /> a Waterra inertia pump to finish the removal of fine-grained sediment. Development activities will <br /> Advanced GeoEnvironmental,Inc. <br /> i <br />