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1 <br /> per boring will be submitted for chemical analysis Samples for analyses will be chosen based on <br /> field screening results Samples will be collected at a minimum of 5-foot intervals with one sample <br /> being collected at the water table <br /> Borings will be drilled with a truck-mounted, hollow-stem auger rig using 10-inch outside <br /> diameter (OD) auger flights Navy as-built drawings and underground utility locators will be <br /> ' consulted prior to drilling to ensure safe borehole placement Soil samples will be collected using a <br /> 2-inch diameter modified California split-spoon sampler with three 6-inch brass Iiner tubes The split- <br /> spoon sampler will collect relatively undisturbed samples using a standard 140-pound hammer <br /> dropped 30 inches This sampling technique allows the split-spoon sampler to be driven ahead of the <br /> auger, minimizing cross-contamination from upper portions of the borehole <br /> Drill cuttings will be containerized in DOT 17H 55-gallon drums Following completion of <br /> each boring, a steam cleaner will be used to decontaminate augers and sampling equipment <br /> I3.3.3 Ground-Water Monitoring Well Construction <br /> Screen interval and monitoring well depths discussed in this FWP are based on available <br /> information on the site hydrogeology and waste sources Local stratigraphic data and field screening <br /> soil gas data will be taken into account when choosing specific well locations, depths, and placement <br /> of the screened interval <br /> Monitoring wells will be installed in accordance with DWR guidelines Borings for <br /> ' monitoring wells will be drilled with 10-inch OD, hollow-stem augers (HSA) Each boring will be <br /> advanced to a depth of approximately 10 feet below the water table The estimated depth to ground <br /> ' water at the site is 8 to 10 feet bgs The monitoring wells will be constructed of 4-inch diameter, <br /> flush pointed, Schedule 40 polyvinyl chloride (PVC) casing installed through the HSA The bottom <br /> 10 to 15 feet of each monitoring well will consist of slotted casing of appropriate size for the aquifer <br /> materials encountered The screened interval of each well will be adjusted in the event that confined <br /> Iaquifer conditions are encountered Placement of the slotted casing will be made such that a <br /> minimum of 5 feet of the screened section extends above and below the existing water table The <br /> ' annular space between the screened casing and the boring will be backfilled with appropriately sized <br /> SAMPL" L62 L <br /> 044-MC TrATR1-0511166/92 16 <br /> 1 <br />