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., 27 June 1996 AGE-NC Project No. 95-0118 Page 3 of 23 h.: VW-1 and VW-2 were advanced to depths of 50 feet bsg. Soil samples were collected ahead of the drill bit using a split-tube sampler loaded with three pre- cleaned 2-inch by 6-inch brass sleeves. Samples were collected at five-foot intervals, using a 140- pound hammer to advance the sampler 18 inches. The number of blows required to advance the sample in 6-inch increments was recorded on the boring log. To avoid cross-contamination, the sampling equipment was washed in an alconox solution and rinsed twice with water prior to each sample run. Augers were steam-cleaned between borings. To preserve each collected soil sample, both ends of the lead sleeve were covered with Teflon sheets, '-= capped and sealed with tope. The samples were stored in a chilled container and transported under chain-of-custody to McCampbell Analytical Laboratory,Inc. (MAI)of Pacheco,California. Selected samples were analyzed for TPH-g and BTE&X in accordance with EPA methods 8015m and 8020, respectively. During drilling, auger returns were monitored for the presence of organic vapors using a photo- ionizing detector (PID: Thermo Environmental 580A, 10.0eV calibrated using isobutylene). 3.2. LOGGING Soil was extruded from the second brass sleeve and screened for the presence .of organic vapors . P g p using a PID and the readings were recorded on the boring logs. The soil was then described in accordance with the United Soil Classification System. Boring logs are included in Appendix A. 3.3. WELL COMPLETION Both VW-1 and VW ere dual-completed as 2-inch diameter vapor extraction/in-situ air sparging wells, using PVC casing with 0.020-111ch slot screen from 45 to 50 feet bsg in both wells, 15 to 35 feet bsg in VW-1 and 20 to 35. feet bsg in VW-2 . A filter pack(#2 sand) was installed from a depth of 43 to 50 feet bsg and bentonite pellets were used to make a 1-foot plug to a depth of 42 feet. A second filter pack was installed from a depth of 14 to 42 feet bsg in VW-1 and from 19 to 42 feet bsg in VW-2. A second bentonite plug was placed above each filter pack to make a 2-foot plug to a depth of 12 feet bsg in VW-I and to 17 feet bsg in VW-2. The wells were then grouted up to the F surface with Portland cement. 'I