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ATTACHMENT B <br /> FIELD AND LABORATORY PROCEDURES <br /> Exploratory Drilling <br /> All soil borings will be drilled using 8-inch hollow-stem auger drilling equipment The two <br /> borings to be converted to groundwater monitoring wells (U-5 and U-6) will be drilled to <br /> approximately 15 feet below the current water level and will be screened from 5 feet above <br /> Total depth will be approximately 25 feet below ground surface (bgs) The boring in the <br /> location of the former waste oil tank (B-4) will be drilled to a depth of approximately 50 feet <br /> bgs or until a minimum of two non detects are measured using field analytical techniques <br /> (PID or FID) A continuous core sample will be collected from this boring to analyze <br /> geological conditions on site Furthermore, after reaching maximum depth, a hydropunch <br /> will be driven and a discrete groundwater sample will be collected Bonngs will be logged <br /> by a Pacific Environmental Group, Inc geologist using the Unified Soil CIassification <br /> System and standard geologic techniques Soil samples will be collected at 5-foot depth <br /> intervals using a California-modified split-spoon sampler The sampler will be driven a <br /> maximum of 18 inches using a 140-pound hammer with a 30-inch drop All soil samples for <br /> chemical analysis will be retained in brass liners, capped with Teflon squares and plastic end <br /> caps, and sealed in Ziplocklm-style bags The samples will be placed on ice for transport to <br /> the laboratory accompanied by chain-of-custody documentation All down-hole drilling and <br /> sampling equipment will be steam-cleaned following the completion of the soil boring <br /> Dawn-hole sampling equipment will be washed in a tri-sodium phosphate or alconox <br /> solution between samples <br /> Groundwater Monitoring Well Installation <br /> The Borings U-5 and U-6 will be converted to groundwater monitoring wells by installing <br /> 2-inch diameter, flush-threaded, Schedule 40 PVC casing with 0 020-inch factory-slotted <br /> screen Approximately 20 feet of screen will be placed in the bottom of the boring An <br /> RMC 2112 sand pack, or equivalent, will be placed in the annular space across the entire <br /> screened interval, and will extend approximately 2 feet above the top of the screen for the <br /> well A 2 to 3 foot bentonite transition seal will be placed atop the sand pack, and a Portland <br /> 910-017 IA/WRKPLN A-1 July 15, 1998 <br />