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ATTACHMENT B FIELD AND LABORATORY PROCEDURES Chevron 9-9840, 4344 Waterloo Road, Stockton, CA • commencement of fieldwork The Site-Specific Health and Safety Plan will be reviewed by the field staff and contractors before beginning field operations at the site each day Exploratory Drilling and Soil Sampling The borings will be drilled to a depth of approximately 75 feet bgs The borings will be advanced using 8-inch hollow-stem auger drilling equipment and logged by a SECOR representative using the Unified Soil Classification System and standard geologic techniques under the direction of a Registered Geologist Soil samples for logging will be collected at 5-foot depth intervals using a California-modified split-spoon sampler The sampler will be driven a maximum of 18 inches using a 140-pound hammer with a 30-inch drop Soil samples for chemical analysis will be retained in brass liners, capped with Teflon squares and plastic end caps, and sealed in clean zip-lock bags The samples will be placed on ice for transport to the laboratory accompanied by chain-of-custody documentation Down-hole drilling and sampling equipment will be steam-cleaned prior to and following the completion of the soil boring Down-hole sampling equipment will be washed in a tri-sodium phosphate or alconox solution between samples Groundwater Monitoring Well Installation and Sampling The borings will be converted to groundwater monitoring wells by installing 2-inch diameter, flush-threaded, Schedule 40 PVC casing with 0 020-inch factory-slotted screen Approximately 15 feet of screen will be placed in the bottom of the borings A grade of sand appropriate to the screen size will be placed in the annular space across the entire screened interval, and will extend approximately 2 feet above the top of the screen for the wells A bentonite seal will extend two feet above the sand pack The monitoring wells will be completed with neat cement from the bentonite seal to ground surface The well casings will be topped with locking caps The wellheads will be contained in watertight well boxes, either traffic rated and flush mounted or in a "stove- pipe" arrangement The boring logs will show the well construction details The wells will be developed after completion by pumping or bailing water from the wells until the water is visibly clear, the well goes dry, or until a maximum of ten casing volumes have been removed After development, water levels will be allowed to partially recover Groundwater samples will then be collected using a disposable teflon bailer, placed into appropriate EPA-approved containers, labeled, placed on ice, and transported to the laboratory accompanied by chain-of-custody documentation The well casings will be surveyed to the nearest 0 01 feet in elevation to a known benchmark Organic Vapor Procedures Soil samples collected during drilling will be analyzed in the field for ionizable organic compounds using an organic vapor meter (OVM) or a photo-ionization detector (PID)