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fl r <br /> ATTACHMENT B <br /> FIELD .AND LABORATORY PROCEDURES <br /> Exploratory Drilling <br /> The soil borings will be drilled using 8-inch hollow-stem auger drilling equipment Borings will <br /> be logged by an IT geologist or engineer using the Unified Soil Classification System and stan- <br /> dard geologic techniques Soil samples will be collected at 5-foot depth intervals using a <br /> California-modified split-spoon sampler The sampler will be driven a maximum of 18 inches <br /> using a 140-pound hammer with a 30-inch drop All soil samples for chemical analysis will be <br /> retained in brass liners, capped with Teflon squares and plastic end caps, and sealed in <br /> Ziplock"'-style bags The samples will be placed on ice for transport to the laboratory <br /> accompanied by chain-of-custody documentation All down-hole drilling and sampling <br /> equipment will be steam-cleaned following the completion of the soil boring Down-hole <br /> sampling equipment will be washed in a trisodium phosphate or alconox solution between <br /> samples <br /> Groundwater Monitoring Well installation <br /> Groundwater monitoring wells will be completed in four soil borings by installing 2-inch <br /> diameter, flush-threaded, Schedule 40 PVC casing with 0020-inch factory-slotted screen <br /> Approximately 10 feet of screen will be used to construct the monitoring wells An RMC 2112 <br /> sand pack, or equivalent, will be placed in the annular space across the entire screened interval, <br /> and will extend approximately 2 feet above the top of the screen for the well A 2 to 3 foot <br /> bentonite transition seal will be placed atop the sand pack, and a Portland cement seal will extend <br /> from the bentonite transition seal to the ground surface The Portland cement seal will be <br /> emplaced by tremie pipe or through the center of the hollow-stem augers in one continuous <br /> operation from the bottom of the interval to be tilled to the top Emplacement of the Portland <br /> cement grout specifically shall not be accomplished by "free fall" from the ground surface The <br /> boring logs will show well construction details <br /> The groundwater monitoring wells will be developed after completion The development proce- <br /> dure for each well will consist of pumping or bailing water from the well until the water is <br /> visibly clear, the well goes dry, or until a maximum of ten casing volumes have been removed <br /> N lrancfpllProjects\Projects19111411`1A10102\91101.t_wp ctoc, B-1 <br />