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0 <br /> i <br /> ATTACHMENT C <br /> FIELD AND LABORATORY PROCEDURES <br /> Exploratory Drilling <br /> The soil borings were drilled using 8-mch hollow-stem auger equipment Borings were <br /> logged by a SECOR International Incorporated scientists using the Unified Soil Classification <br /> System and standard geologic techniques under the direction of a registered geologist Soil <br /> samples for logging were collected at 5-foot depth intervals using a California-modified split- <br /> spoon sampler The sampler was driven a maximum of 18 inches using a 140-pound hammer <br /> with a 30-inch drop Down-hole drilling and sampling equipment was steam-cleaned <br /> following the completion of each soil boring Down-hole sampling equipment was washed in <br /> a tri-sodium phosphate or alconox solution between samples <br /> Groundwater Monitoring Well Installation <br /> Each of the groundwater monitoring wells was constructed of 4-inch-diameter schedule 40 <br /> PVC blank casing and 0 020-inch-slot well screen with flush threads A 43-sand filter pack <br /> was installed in the annulus from the bottom of each borehole to at least 2 feet above the top <br /> of the well screen, followed by a well seal consisting of a 2-foot-thick hydrated bentonite layer <br /> overlain by grout to ground surface Each well was secured by a locking expandable well cap <br /> and fitted with a tragic-rated well box set in concrete <br /> Soil Sampling <br /> Soil samples wei e collected by advancing 2-inch-diameter bi ass sample liners into undisturbed <br /> soil, reached through the center of the drill auger Soil samples for chemical analysis were <br /> retained in the brass liners, labeled, and capped with Teflon sheets and plastic end caps The <br /> samples were then sealed in zip-lock bags, placed on ice, and transported to the laboratory <br /> accompanied by the appropriate chain-of-custody documentation <br /> Soil Sampling for Stockpiled Soil <br /> Soil samples were collected by advancing 2-inch diameter brass sample hnei s into the soil <br /> stockpile, after removing approximately 6 inches to I foot of surface material in the sample <br /> location One composite sample was collected per approximately 100 cubic yards of soil Soil <br />