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• a ATTACHMENT C SAMPLING AND ANALYSIS PROCEDURES Exploratory Drilling and Soil Sampling The soil borings will be drilled using HSA drilling equipment with 8.25-inch OD augers. Borings will be logged by a URS geologist using the Unified Soil Classification System. Soil samples will be collected from the borings at 10- foot intervals in brass tubes. Soil samples for chemical analysis will be retained in brass tubes, capped with Teflon® squares and plastic end caps,and sealed in clean zip-lock bags. The samples will then be placed on ice for transport to the laboratory accompanied by chain-of-custody documentation. Downhole drilling and sampling equipment will be steam-cleaned following the completion of each soil boring. Downhole sampling equipment will be washed in a non-phosphate soap and deionized water solution between samples. Laboratory Analysis of Soil Samples Soil samples are analyzed for GRO by EPA method 8015B, and BTEX, fuel oxygenates, including 1,2-DCA by EPA Method 8260B (preparation by EPA Method 5030). Drummed soil samples are analyzed for GRO and BTEX by EPA Methods 8015/8021 (preparation by EPA Method 5030); lead content is analyzed by EPA 6000/7000 Series Methods. Soil Sampling from Drummed Soil A portion of soil from each drum will be placed into a 2-inch-diameter brass sample liner,labeled,and capped with Teflon® sheets and plastic end caps. The samples are then sealed in zip-lock bags,placed on ice, and transported to the laboratory accompanied by the appropriate chain-of-custody documentation. Prior to analysis, the sample will be composited by the laboratory. Groundwater Monitoring Well Installation The groundwater monitoring wells will be constructed of 2-inch schedule 40 PVC blank casing and 0.020-inch machine slotted well screen with flush threads. A #3-sand filter pack will be installed in the annulus from the bottom of the borehole to at least 2 feet above the top of the well screen,followed by a transition seal consisting of a 3-foot-thick hydrated bentonite plug, which in turn will be overlain by neat cement grout to ground surface. The well will be secured with a locking expandable well cap and fitted with a traffic-rated well box set in concrete. Groundwater Sample Laboratory Procedures Groundwater samples are analyzed for the presence of GRO, benzene, toluene, ethylbenzene, xylenes (total), fuel oxygenates,and lead scavengers(1,-DCA and EDB)using EPA Method 8260. Decontamination Procedures Prior to sampling each well, reels and pumps will be decontaminated with a steam cleaner. Sensitive equipment such as the water level sounder will be sprayed with a non-phosphate soap and deionized water solution and rinsed with deionized water. All water used for equipment decontamination is collected and contained in a truck-mounted water tank. Page C-1