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ATTACHMENT D FIELD AND LABORATORY PROCEDURES Exploratory Drilling The monitoring wells were drilled using 8-inch hollow-stem auger drilling equipment. Soil boring B-1 was advanced using Enviro-Core sampling procedure (see Attachment Q. Borings were logged by a SECOR International Incorporated scientists using the Unified Soil Classification System and standard geologic techniques under the direction of a registered geologist. Soil samples for logging boring B-1 were collected continuously and MW-5 through MW-7 were collected at 5-foot depth intervals using a California-modified split- spoon sampler. The sampler was driven a maximum of 18 inches using a 140-pound hammer with a 30-inch drop. All soil samples for chemical analysis were retained in brass or plastic liners, capped with Teflon squares and plastic end caps, and sealed in clean zip-lock bags. The samples were placed on ice for transport to the laboratory accompanied by chain-of- custody documentation. All down-hole drilling and sampling equipment was steam-cleaned following the completion of each soil boring. Down-hole sampling equipment was washed in a tri-sodium phosphate or alconox solution between samples. Groundwater Monitoring Well Installation Each of the groundwater monitoring was constructed of 2-inch-diameter schedule 40 PVC blank casing and 0.020-inch-slot well screen with flush threads. A #3-sand filter pack was installed in the annulus from the bottom of each borehole to at least 2 feet above the top of the well screen, followed by a well seal consisting of a 2-foot-thick hydrated bentonite layer overlain by grout to ground surface. Each well was secured by a locking expandable well cap and fitted with a traffic-rated well box set in concrete. Soil Sampling Soil samples were collected by advancing 2-inch-diameter brass sample liners into undisturbed soil, reached through the center of the drill auger or 1 inch plastic liner into undisturbed soil , reach through the center of the enviro-core rods. Soil samples for chemical analysis were retained in the brass or plastic liners, labeled, and capped with Teflon sheets and plastic end caps. The samples were then sealed in zip-lock bags, placed on ice, and transported to the laboratory accompanied by the appropriate chain-of-custody documentation.