ARCHIVED REPORTS_XR0005314 - Laserfiche WebLink

Home Browse Search

. 17 April 1996 ' AGE-NC Project No 95-0120 Page 4 of 7 ' 3 3 BORING LOGS During drilling activities, sample duplicates were described on boring logs using the Unified Soil Classification System (USCS), and monitored for the presence of organic vapors using a photo- ionization detector (PID Thermo Environmental 580A, 10 0 eV, calibrated to isobutylene) Boring ' logs are summarized in Appendix A ' 3 4 VAPOR EXTRACTION WELL COMPLETION VWl through VW3 were completed as 2-inch diameter soil vapor extraction (SVE) wells Boring locations are illustrated in Figure 2 -Site Plcai As-built SVE well construction diagrams are included as Figures 3 through 5 Bentonite was utilized at the bottom of each boring to create a plug A well casing was emplaced through the hollow stem of the augers The augers were incrementally raised as a 93 Lonestar Lapis Luster sand was slowly poured down the annulus between the well casing and the inner wall of the hollow stem auger A filter pack was placed adjacent to the screen (0 020 inch screen size) from the bottom of the screen to a point approximately 2 feet above the top of the screen A 2-foot seal of bentonite chips was placed above the filter pack and hydrated with clean tap water The remaining annular space was sealed to the surface with Portland cement 3 5 QUARTERLY MONITORING AND SAMPLING ' On 31 October 1995 and 08 February 1996, ground water depths and well depths in all wells were measured to the nearest 0 01 foot utilizing a Solist water level meter After water levels were ' measured, approximately 7 to 9 gallons of water (a minimum of three well volumes) were purged from each well utilizing disposable teflon bailers Temperature, pH and conductivity were measured at well volume intervals using an ICM model 52200 water analyzer Stabilization data and field logs ' are included in Appendix B Purged water was stored in 55-gallon drums stored on-site in an area inaccessible to the general public ' After purging, each well was allowed to recover for a minimum of one hour prior to sample collection Water samples were collected from each well using dedicated, disposable polyethylene bailers and new nylon rope Sufficient sample was collected from each well to fill three 40-m1 EPA vials containing hydrochloric acid as a preservative, and one 1-liter amber bottle Care was taken to ensure that no air bubbles were present in the VOAs after filling and capping Ground-water sample containers were labeled with the well designation, date, time, and samplers initials ' Followng collection, each sample was logged on a chain-of-custody, placed in a chilled container and g p transported to Alpha Analytical Laboratories (AAL) in Atwater, California Ground water samples were analyzed for TPH-g, TPH-d and BTE&X in accordance with EPA methods 8015 modified for