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11 March 2014 AGE Project No. 96-0236 Page 30 of 32 BORING ADVANCEMENT AND SOIL SAMPLING Utilizing a truck-mounted, hollow-stem drill rig equipped with 8.25-inch diameter hollow- stem augers, nine pilot soil borings will be advanced to a depth of approximately 30 feet bsg (shallow) and seven pilot borings will be advanced to a depth of 50 feet bsg (intermediate). Beginning at 5 feet bsg, relatively undisturbed soil samples will be collected from selected locations at 5-foot intervals using a California modified split-spoon sampler fitted with 2-inch diameter, 6-inch long steel sleeves. Upon removal from the sampler, the sample sleeves will be separated and the exposed ends of a selected sleeve will be covered with Teflon sheets, capped, and sealed with tape. Soil samples will be visually classified by AGE personnel 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 and transported under chain of custody to a CDPH-certified laboratory for analysis for the constituents listed in Section 2.2. WELL COMPLETION The pilot soil borings will be completed as shallow and intermediate injection wells utilizing two-inch diameter, Schedule 40 PVC blank well casing and 0.020-inch slotted well screen installed from 10 feet to 25 feet bsg and from 30 to 50 feet bsg. A diagram of the proposed injection well designs are depicted in Figures 21 and 22. After installing the well casing in each pilot boring, a filter pack material consisting of pre-washed #3 Lonestar sand will be added through the augers from total depth to approximately one (shallow) to two (intermediate) 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 three-foot bentonite seal will be placed above the filter pack to minimize the potential for grout penetration into the screened section of the wells. The bentonite seal will be formed by pouring bentonite chips into the annulus and allowing them to settle on the filter pack. The bentonite chips will be allowed to hydrate for the duration of time specified by the manufacture, prior to grouting. The remaining annular space 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 6 gallons of water per 94- Advanced GeoEnvironmental, Inc.