Laserfiche WebLink
r <br /> 15 January 1999 <br /> AGE-NC Project No. 98-0440 . <br /> _ Page 2 of 4 <br /> 2:2'. -GROUND WATER SAMPLING <br /> Prior to-sampling wells MW-I•through MW-4; ground water levels achieved a minimum of 80 <br /> percent recharge.' Ground_.v titer sa' ples,were,collected from the purged wells utilizing news <br /> ' I disposable polyethylene bailers, one-liter amber bottles and four 40-m1 EPA-approved VOA vials <br /> containing 0.5 ml 18%.hydrocliloric acid as a preservative. Care was taken to ensure that visible`air <br /> bubbles were not present in the vials after.filling and`capping..Ground water sample container's:were ' . <br />' labeled with the'well designation date time and sampler's initials.' <br /> 2.3. LABORATORY ANALYSIS OF GROUNDWATER SAMPLES' <br /> ;Each ground water sample was logged on a chain-of custody form, placed,in a chilled container and <br /> transported to a California Department of Health Services'(DHS)-certified laboratory for analysis <br /> in accordance with: ; <br /> • <br /> ' EPA Method 8015M for total 'petroleum hydrocarbons quantified as gasoline and diesel <br /> (TPH-g and,TPH-d, respectively), ' ~ <br /> `EPA Method 8020 for volatile aromatics (benzene, toluene, ethyl benzene and, xylene: . <br /> BTEX) with methyl-tertiary butyl;ether(MTBE), and <br />' •EPA Method 8260 for tertiary butanol (TBA),'.di-isopropyl ether (DIPE),'ethyl tert butyl <br /> _ y <br /> ether(ETBE), tert amyl methyl ether (TAME)'and MTBE. ; <br />' 3.0. FINDINGS <br /> From the.field data, AGE,'Nvas able-to -determine the ground water flow direction and.gradient. <br /> Laboratory analysis detected-petroleum hydrocarbons in three ground water:sanlples; no oxygenated <br /> fuel additives were detected in-around water'sam' les. <br /> p <br /> 3..-L , RELATIVE GROUND WATER ELEVATION AND GRADIENT <br /> During,the'Ocfober 1998 monitoring event, depths to ground water from wells MW-1,through MW- <br /> 4 were measured between 9.78 Ahd'i'0.52 feet-below the top'of well casings; ground water elevations <br /> were calculated betweeir29.91'feet and 30,68 feet above mean sea level. Ground water elevation at <br /> the site decreased an average 1.2I feet between the July 1998 and the October 1998 ground water.. <br /> monitoring-events. The groundwater elevation data for MW-l-through-MW-4 during the October <br /> Advanced CcoEnvironmental,Inc, <br />