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F . 17 April 1996 AGE-NC Project No 95-0120 Page 3 of 7 confined due to the presence of interbedded fine and coarse grained sediments Review of Lines of Equal Elevation of Water in Wells 1993 published by the Department of Water Resources - San Joaquin Valley suggests that regional ground water flow is towards the southeast 3.0. PROCEDURES ' 3 1 DRILLING AND SAMPLING On 06 December 1995, three soil bonngs B 12, B 13 and B 14 were advanced at the site and converted to vapor extraction wells VW I, VW2 and VW3, respectively, utilizing a CME-75 truck mounted drill ng equipped with 8-inch diameter hollow stem augers Soil bonngs B 12 through B 14 were advanced to depths of approximately 70 feet bsg The drill rig and two man crew were provided by Mitchell Drilling Environmental (NDE) of Rancho Cordova, California Boring locations are illustrated on Figure 2 -Site Plan Discrete soil samples were collected at five-foot intervals, beginning at a depth of approximately 15 feet bsg, utilizing a California split-spoon sampler and three brass sleeves The sampler was driven by dropping a 140-pound weight from a height of 30 inches The number of blows required to drive ' each 6-inch length of the sampler (blow counts) was recorded on boring logs by an AGE staff geologist (Appendix A) Upon sample retrieval, the middle brass sleeve was removed from the sampler Both ends of the sleeve were covered with Teflon sheets, capped and sealed with tape Each sample was labeled with the following boring location, depth, time, date, and sampler's initials The samples were placed in a chilled container and transported under chain-of-custody protocol to a California state-certified hazardous waste laboratory Selected soil samples were analyzed for total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d), and volatile aromatics (BTE&X) in accordance with EPA methods 8015 for fuels and 8020, respectively Soil cuttings, soil sample duplicates and rmseate generated during drilling activities were placed in properly labeled D 0 T model 17H 55-gallon drums and stored on-site in an area inaccessible to the general public 3 2 EQUIPMENT DECONTAMINATION ' Hollow stem augers were steam cleaned prior to each boring advancement Sampling tools and brass sleeves used for sample collection were thoroughly washed with a solution of Alconox, and rinsed twice with clean water prior to each sampling run