ARCHIVED REPORTS XR0007778 - Laserfiche WebLink

Home Browse Search

15 November 1995 AGE-NC Project No 95-0142 ` Page 3 of 19 I3.0. SOIL VAPOR EXTRACTION WELL INSTALLATION 3 1 DRILLING AND SAMPLING _ On 25 and 26 September 1995, four soil bonngs were drilled at the site Each boring was drilled using a truck-mounted HT-55 dell ng equipped with hollow-stem augers The drill ng and a three- man crew were supplied by NLtchell Drilling Environmental, Inc of Rancho Cordova, California Bonngs VE-1, VE-2, VE-3 and VE4 were advanced to depths of 45 feet below surface grade (bsg) Soil samples were collected ahead of the drill bit using a split-tube sampler loaded with three pre- cleaned 2-mch 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-contammation, 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 For each soil sample,both ends of the lead sleeve were covered with Teflon sheets, capped and sealed with tape 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 ' Two soil samples were also transported to an independent microbiologist, Mr A Keith Kaufmann of Culver City, California, and analyzed for physicochemical properties and microbiological ' enumeration During drilling, auger returns were monitored for the presence of organic vapors using a photo- ionizing detector(PID Thermo Environmental 580A, 10 OeV calibrated using isobutylene) ' 32 LOGGING Soil was extruded from the second brass sleeve and screened for the presence of organic vapors 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 3WELL COMPLETION ' All four bonngs were dual-completed as 2-Erich diameter vapor extraction wells (VE-1, VE-2, VE-3 and VE-4), using PVC casing with 0 020 screen from depths of 30 to 45 feet and 10 to 25 feet A . filter pack (#2 sand) was installed from a depth of 28 to 45 feet and bentonite pellets were used to ' make a Moot plug to a depth of 25 feet A second filter pack was installed from a depth of 8 to 25 I