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ATTACHMENT A FIELD AND LABORATORY PROCEDURES Groundwater Monitoring Well Installation Soil borings for exploratory soil sampling and well installation were drilled using 8-inch hollow stem auger drilling equipment to depths between 75 and 92 feet bgs Barings were logged by a Pacific Environmental Group, Inc geologist using the Unified Soil Classification System and standard geological techniques A continuous core sample was collected from MW-1 Soil samples for logging in Wells MW-2 and MW-3 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-inch 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 were steam-cleaned following the completion of the soil boring Down-hole sampling equipment was washed in a tri-sodium phosphate or alconox solution between samples The borings were converted to a groundwater monitoring well by installing 2-mch diameter, flush-threaded, Schedule 40 PVC casing with 0 020-inch factory-slotted screen Approximately 20 feet of screen was placed in the bottom of the boring RMC Lonestar 2X12 sand pack was placed in the annular space across the entire screened interval, and extended approximately 2 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 extended from the bentonite transition seal to the ground surface The Portland cement seal was placed by temie pipe through the center of the hollow-stem augers in one continuous operation from the bottom of the interval and filled to the top The boring logs show well construction details The groundwater monitoring wells were developed 24 hours after completion Laboratory Procedures Selected soil samples collected from the soil borings and groundwater samples collected from the wells were analyzed for the presence of TPH-g, TPH-d, BTEX, and MtBE using modified EPA Methods 8015/8020 and DHS Luft Additionally, selected water samples were analyzed by EPA Method 8260