Laserfiche WebLink
1 <br /> ' ATTACHMENT C <br /> FIELD AND LABORATORY PROCEDURES <br /> Exploratory Drilling and Soil Sampling <br /> g <br /> The soil borings were drilled using 8-inch hollow-stem auger drilling equipment Borings <br /> ' were logged by a SECOR International Incorporated scientist using the Unified Soil <br /> Classification System and standard geologic techniques under the direction of a registered <br /> i ' geologist Soil samples for logging were collected at 5-foot depth intervals using a <br /> California-modified split-spoon sampler The sampler was driven into undisturbed soil a <br /> maximum of 18 inches using a 140-pound hammer with a 30-inch drop Depth discrete <br /> ' groundwater samples were collected using a hydropunch in seperatly cored boring adjacent to <br /> S13-1 and S13-2 Soil samples for chemical analysis were retained in brass liners, labeled, <br /> capped with Teflon squares and plastic end caps, and sealed in clean zip-lock bags The <br /> ' samples were placed on ice for transport to the laboratory accompanied by chain-of-custody <br /> documentation Down-hole dnIling and sampling equipment was steam-cleaned following <br /> the completion of each soil boring Down-hole sampling equipment was washed in a tn- <br /> ' sodium phosphate or alconox solution between samples <br /> ' Groundwater Monitoring Well Installation <br /> Each of the groundwater monitoring (4-inch) and soil vapor extraction (2-inch) wells were <br /> ' constructed of schedule 40 PVC blank casing and 0 020-inch-slot well screen with flush <br /> threads A #3-sand filter pack was installed in the annulus from the bottom of each borehole <br /> to at least 2 feet above the top of the well screen, followed by a well seal consisting of a 2- <br /> foot-thick hydrated bentonite layer overlain by grout to ground surface Each well was <br /> secured by a locking expandable well cap and fitted with a traffic-rated well box set in <br /> concrete <br /> Soil Sampling for Stockpiled Soil <br /> ' Soil samples were collected by advancing 2-inch diameter brass sample liners into the soil <br /> stockpile, after removing approximately 6 inches to 1 foot of surface material in the sample <br /> location One composite sample was collected per approximately 100 cubic yards of soil <br /> Soil samples for chemical analysis were retained in the brass liners, labeled, and capped with <br /> �� Teflon sheets and plastic end caps The samples were then sealed in zip-lock bags, placed on <br />