ARCHIVED REPORTS_XR0012031 - Laserfiche WebLink

Home Browse Search

i i20 May 1998 • AGE-NC Project No 95-0130 iPage 2 of 5 2 2 GROUND WATER SAMPLING ' The round water levels i m W-1 W- W-1 VW-2A and VW-3A, A g n monitoring wells M through M 5,V C, , i achieved a minimum of 80 percent recharge recovery prior to sample collection Ground water samples were collected utilizing disposable polyethylene bailers and new nylon rope Sufficient ground water sample was collected from each well to fill three EPA-approved 40-m1 VOA vials i containing 0 5 ml 18%hydrochloric acid as a preservative for the samples Caie was taken to ensure that visible air bubbles were not present in the VOA vials after filling and capping Ground water sample containers were labeled with the well designation, date, time, and sampler's initials i 23 LABORATORY ANALYSIS OF GROUND WATER SAMPLES iEach ground water sample was logged on a chain-of-custody form,placed In a chilled container and transported to a California state-certified laboratory for analysis in accordance with EPA Methods i9 8015M for total petroleum hydrocarbons quantified as gasoline (TPH- g), i• . 8020 for volatile aromatics (benzene, toluene, ethyl benzene and xylene BTE&X) with methyl-tertiary butyl ether (MTBE), and i • 8260 for volatile organics (including oxygenates) The laboratory report(Castle Analytical Laboratory Reference No 86910 to 86917 and McCampbell Analytical Inc Lab I D 86910 to 86917) and chain-of-custody forms are presented in Appendix B 1 i3.0. FINDINGS 3 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT iThe depths to ground water in wells MW-1 through MW-5, VW-1C, VW-2A and VW-3A were measured at 43 98 to 45 91 feet below the top of well casings Between December 1997 and March ' 1998, ground water elevation increased an average 2 83 feet at the site The ground water elevation data for MW-I though MW-5 during the March 1998 ground water monitoring event is depicted in Figure 3 iDuring the March 1998 monitoring event, ground water was between 16 02 and 2 09 feet above the top of screened intervals from monitoring wells MW-1 through MW-5 and VW-1 C As a result, the ' screened intervals from these wells are completely submerged, and may not yield water samples fully representative of ground water conditions near the top of the saturated zone where fuel Advanced GeoEnvlronmental,Inc i