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ATTACHMENT B FIELD AND LABORATORY PROCEDURES Chevron 9-9840, 4344 Waterloo Road, Stockton, California Health and Safety As required by the Occupational Health and Safety Administration (OSHA) Standard "Hazardous Waste Operations and Emergency Response" guidelines (29 CFR 1910 120), and by California Occupational Health and Safety Administration (Cal-OSHA) "Hazardous Waste Operations and Emergency Response" guidelines (CCR Title 8, Section 5192), SECOR prepared a Site-Specific Health and Safety Plan prior to the commencement of fieldwork The Site-Specific Health and Safety Plan was reviewed by the field staff and contractors before beginning field operations at the site each day Exploratory Drilling and Soil Sampling The borings were advanced to a depth of approximately 75 feet bgs, 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 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 Soil samples for chemical analysis were retained in brass liners, capped with Teflon squares and plastic end caps, and sealed in clean zip-lock bags The samples were placed on ice for transport to the laboratory accompanied by chain-of-custody documentation Down-hole drilling and sampling equipment was steam- cleaned prior to and following the completion of each soil boring Down-hole sampling equipment was washed in an AlconoxTM solution between samples Groundwater Monitoring Well Installation and Sampling The 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 Approximately 15 feet of screen was placed in the bottom of each boring A grade of sand appropriate to the screen size was placed in the annular space across the entire screened interval, and extends approxnnately 2 feet above the top of the screen for each well A bentonite seal extends two feet above the sand pack The monitoring wells were completed with neat cement from the bentonite seal to ground surface The well casings were topped with locking caps The wellheads were contained in traffic rated, flush mount, watertight well boxes The boring logs show well construction details The wells were developed after completion by pumping or bailing water from the wells until the water is visibly clear, the wells went dry, or until a maximum of ten casing volumes had been removed After development, water levels were allowed to partially recover Groundwater samples were then collected using a disposable teflon bailer, placed into appropriate EPA-approved containers, labeled, placed on ice, and transported to the laboratory accompanied by chain-