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ATTACHMENT A <br /> FIELD AND LABORATORY PROCEDURES <br /> Drilling and Monitoring Well Installation <br /> Boring Installation <br /> The boring for Well U-4 was drilled according to state and local regulatory guidelines The <br /> wellbore was drilled using 8-inch diameter hollow-stem auger drilling equipment The boring <br /> was logged by a Pacific Environmental Group, Inc geologist using the Unified Soil <br /> Classification System and standard geologic techniques Soil samples for logging and <br /> chenucal analysis were collected by advancing a California-modified split-spoon sampler with <br /> 6-inch brass liners into undisturbed soil beyond the tip of the auger The sampler was driven a <br /> maximum of 18 inches using a 140-pound hammer with a 30-inch drop The brass liner <br /> containing the deepest 6 inches of soil from each sample interval was retained for chemical <br /> analysis, and was capped with Teflon tape squares and plastic end caps and then placed in a <br /> sealable plastic bag These samples were placed on ice for transport to the laboratory <br /> accompanied by chain-of-custody documentation All down-hole drilling equipment was <br /> steam-cleaned prior to drilling <br /> All residual soils obtained from drilling operations were stockpiled on site and covered with <br /> plastic sheeting until laboratory analyses were completed and the results evaluated <br /> Arrangements were then made for disposal to an appropriate landfill based on analytical <br /> results <br /> Groundwater Monitoring Well Installation <br /> The boring was converted to a groundwater monitoring well by the installation of 2-inch <br /> diameter flush-threaded Schedule 40 PVC casing with 0 020-inch factory-slotted screen from <br /> 6 to 20 feet bgs, and Schedule 40 PVC solid casing to the ground surface The annular space <br /> was filled with RMC 2 x 12 sand across the entire screened interval, extending approximately <br /> a 112 foot above the top of the screen The wells was then sealed with approximately a <br /> 112 foot of bentonite above the top of the sand pack, and a cement seal to the ground surface <br /> 3100971B1REPORT DOC A - 1 February 14, 1997 <br />