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4. - J . y 1, y .'1 r1•.r.y t _ t 1 ',Y.1� J. 4 • �.4 12'''August 2002' AGE-NC{N _ect,No:95-0114 f. Page`2 of 4 L ' „ �2'2. COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES Groundwater samples were collected frorrieach•well using new`disposable,bailers.following recovei-y of at least 80%,ofthe re- ur 'e casizi water volume. Immediately upon,reirieval, the samples were p p g g transferred into,40-m1 EPA-approved VOA vials containing-O..5 ml of hydrochloric acid(18%) as,a ' sample preservative, and were properly labeled. The satriples were•transported in. chilled container r. under chain-of-custody,to Cal Tech Enviro&hental Laboratories,.Inc'(CTEU a State of California ' Department of Health Services .(DHS)-certified laboratory.in Paramount; California. The samples, Ye analyzed for: ; Volatile-organic compounds(VOCs),specifically benzene,toluene;ethylbenzene and xylenes (BTEX) and the `fuel additives methanol, ethanol; ethylene dibromide ' (EDB), 1,2- dichloroethane(1,2-DCA),tertiary butanol(TBA),di--isopropyl ether(DIPS);ethyl tert butyl ether (ETBE), tent amyl methyl ether(TAME), and MTBE by EPA Method 8260B; and Total etroleum h drocarbans quantified as Stoddard solvents (TPH-ss) by EPA Method P y 8015 Modified. 3.0. FINDINGS ; Ground water flow direction and gradient were inferred,from the field data:The current distribution ,of dissolved petroleum hydrocarbons and dissolved chlorinated hydrocarbons was assessed from ' laboratory.analical results of the soil and,ground waters les: 3.1. GROUND WATER GRADIENT.AND'.DIRECTION During the June 2002 g'raund water monitoring event, the,depth to ground.water at the site ranged from-22.73 to 24.26'feet below the tops•of the well casings. The groundater flow-direction and gradient were toward the northeasi-frorn`well MW-5 toward well MW-1:0,' with a gradient of ' approxilnately 0.001.8 feet/feet. Ground water elevation data are summarized in Table.A.'. The contoured ground,water,elevation for the ground water monitoring event is depicted in Figure 3: :'.. Wells MW-1,through MW, were screened between 30 or,34 and 50 feetbsg; wells MW-6 through- « , MW-10-were screened between 20 or 25 and 45 or 50.feet bsg: The ground water level was more than 10 feet above'the tops of the screened intervals of wells MWA and MW-2, more,than'6 feet r. above the tops of the,screened intervals of MW-3R, MW-4 and MW-5, and'between'.1 and,2 feet ; abov,'e ihe.t6ps of the screened intervals`of.MW-6 and MW-7:' Advanced GeoEnvtrottmental Inc.