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' ATTACHMENT A FIELD AND LABORATORY PROCEDURES ' Exploratory Drilling ' The soil borings for well installations were drilled using 8-inch hollow-stem auger drilling equipment to depths of approximately 30 feet below ground surface (bgs) or approximately 10 to 15 feet into first groundwater The soil baring drilled onsite to evaluate the vertical ' extent of hydrocarbons extended to approximately 37-1/2 feet as described in the work plan Borings were logged by a Pacific Environmental Group, Inc geologist using the Unified Soil Classification System and standard geologic techniques Soil samples for logging were ' collected at 5-foot depth intervals using a California-modified split-spoon sampler The sampler was driven a maximum of 18 inches using a 140-pound hammer with a 30-mch drop All soil samples for chemical analysis were retained in brass liners, capped with Teflon . squares and plastic end caps The samples were placed on ice for transport to the laboratory accompanied by chain-of-custody documentation All down-hole drilling and sampling ' equipment was steam-cleaned following the completion of the soil boring Down-hole sampling equipment was washed in a tn-sodium phosphate or alconox solution between samples ' Soil vapor series samples were collected by hydraulically advancing a 1 to 2 inch diameter rod with a retractable tip at approximately the 3, 6, and 9 foot intervals, the rod was raised ' slightly and tip retracted Disposable tubing with a filter tip was lowered within the rods and vapor was extracted into a Tedlar bag utilizing a diaphragm pump ' Groundwater Monitoring Well Installation Three borings were converted to groundwater monitoring wells by installing 2-inch diameter, ' flush-threaded, Schedule 40 PVC casing with 0 020-inch factory-slotted screen Approxi- mately 20 feet of screen were placed in the bottom of the boring An RMC 2112 sand pack, or equivalent, was placed in the annular space across the entire screened interval, and ' extended approximately 1 feet above the top of the screen for the well A 2 foot bentonite transition seal was placed atop the sand pack, and a Portland cement seal will extend from the bentonite transition seal to the ground surface The Portland cement seal was emplaced by 910-017 1A/SOLGWRPT A - 1 December 2, 1998