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' ATTACHMENT C <br /> FIELD AND LABORATORY PROCEDURES <br /> 1 <br /> ' Exploratory Drilling and Soil Sampling <br /> The soil borings were drilled using 10-inch hollow-stem auger drilling equipment Borings <br /> ' were logged by a SECOR International Incorporated scientist using the Unified Soil <br /> Classification System and standard geologic techniques under the direction of a registered <br /> geologist Soil samples for logging were collected at 5-foot depth intervals using a <br /> California-modified split-spoon sampler The sampler was driven into undisturbed soil a <br /> maximum of 18 inches using a 140-pound hammer with a 30-inch drop Soil samples for <br /> ' chemical analysis were retained in brass liners, labeled, capped with Teflon squares and <br /> plastic end caps, and sealed in clean zip-lock bags The samples were placed on ice for <br /> transport to the laboratory accompanied by chain-of-custody documentation Down-hole <br /> ' S drilling and sampling equipment was steam-cleaned following the completion of each soil <br /> boring Down-hole sampling equipment was washed in a tri-sodium phosphate or alconox <br /> solution between samples <br /> ' it Vapor Extraction and Groundwater Monitoring So p g Well Installation <br /> ' Each of the groundwater monitoring (flinch) and soil vapor extraction (2-inch) wells were <br /> constructed of schedule 40 PVC blank casing and 0 020-inch-slot well screen with flush <br /> threads A#3-sand filter pack was installed in the annulus from the bottom of each borehole <br /> ' to at least 2 feet above the top of the well screen, followed by a well seal consisting of a 2- <br /> foot-thick hydrated bentonite layer overlain by grout to ground surface Each well was <br /> ' secured by a locking expandable well cap and fitted with a traffic-rated well box set in <br /> concrete <br /> ' Soil Sampling for Stockpiled Soil <br /> Soil samples were collected by advancing 2-inch diameter brass sample liners into the soil <br /> ' stockpile, after removing approximately 6 inches to 1 foot of surface material in the sample <br /> location One composite sample was collected per approximately 100 cubic yards of soil <br /> Soil samples for cherrucal analysis were retained in the brass liners, labeled, and capped with <br /> 1 Teflon sheets and plastic end caps The samples were then sealed in zip-lock bags, placed on <br />