ARCHIVED REPORTS_XR0005753 - Laserfiche WebLink

Home Browse Search

r1i k ATTACHMENT C FIELD AND LABORATORY PROCEDURES Exploratory Drilling The soil borings will be drilled using 8-inch and 10-inch hollow-stem auger dnlling equipment to a depths of approximately 40 to 80 feet bgs Borings will be logged by a SECOR International Incorporated geologist using the Unified Soil Classification System and standard geologic techniques 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 All 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 All down-hole drilling and sampling equipment will be steam-cleaned following the completion of the soil boring Down-hole sampling equipment will be washed in a tn- sodium phosphate or alconox solution between samples Soil Vapor Extraction Well Installation Selected borings may be converted to soil vapor extraction wells by installing 2-inch diameter, flush-threaded, Schedule 40 PVC casing with 0 020-inch factory-slotted screen An appropriate length of screen will be placed in the bottom of the boring 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 well A bentonite seal will extend three feet above the sand pack The monitoring well will be completed with neat cement from the bentonite seal to ground surface The well casing will be topped with a locking cap The well head will be contained in a watertight well box, either traffic rated and flush mounted The boring logs will show well construction details Groundwater Monitoring Well Installation Four borings will be converted to groundwater monitoring wells by installing 4-inch diameter, flush-threaded, Schedule 40 PVC casing with 0 020-inch factory-slotted screen Approximately 20 feet of screen will be placed in the bottom of the boring 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 well A bentonite seal will extend three feet above the sand pack The 077 4 t941 310!W KPLAN February 29,2000