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04 October 1999' <br /> SAGE-Nq;Project,No 95-0144 <br /> !' I Y <br /> Page 2 of 4 <br /> I e '4 <br /> " 'approved drums onsite 4 _ <br /> r r 2 2 COLLECTION OF GROUND WATER SAMPLES <br /> Water samples.wereLcollected from`eachfpurgedFwell using new disposable bailers }Samples were ' <br /> transferred into 40-m1'EPA-approved VOA vials containmg 0 5 ml t18% hydrochloric acid as'a <br /> sample preservative and into;I-lifer"amber bottles without preservative The samples were labeled, <br /> { stored on t'ce and transporfed under chain-of custody'to` McCampbell Analytical, Inc (MAI), a <br /> Ca iforma Department of Health ServicesL(DHS)-certified analytical laboratory Each sample was, <br /> analyzed for , <br /> -1 Total petroleum hydrocarbons quaritified'as gasoline(TPH-g), diesel (TPH-d) and motor oil ' ;r <br /> (TPH in in accordance with EPA Methods 503018015m <br /> Volatile aromatic hydrocarbons (benzene,'toluene, ethylbenzene and total xylenes, BTEX) , <br /> ' with methyl tertiary-butyl"ether (MTBE) in accordance vaith EPA Method 8020/602 <br /> ' §" •' tFuel oxygenates (di-isopropyl ether [DIPE], ethyl tertiary-butyl ether [ETBE], MTBE, ` ? �k, <br /> tertiary-amyl methyl ether [TAME].and tertiary butanol [TBA]) m accordance,with EPA } <br /> I <br /> Method 8260 modified <br /> FINDINGS <br /> Groundwater elevation and flow' direction were calculated from field data, hydrocarbon-impact to ;ground water was inferred from laboratory analysis of the ground water samples <br /> h yy <br /> 3 1 RELATIVE Gr , , - <br /> ROUND WATER ELEVATION AND GRADIENT', <br /> k` The elevation of ground water in each well was calculated by subtracting the depth to water from,', <br /> the surveyed casing elevatiori(Table 1) .Between May'and August`l999, ground water elevation `r - <br /> k A decreased an average'of 0 53 feet in monitoring wells MW-1913, MW-20B and,MW-21 B, screened; <br /> below a clay layer Ground water elevation decreased an,average of 0 38 feet in the remaining wells <br /> The�approximate hydraulic gradient for the August 1999 monitoring levent was calculated to be 0 003 ' <br /> ''t w ft/JT,with a northerly flow direction Ground water elevation contours derived from data collected <br /> on, O'August 1999are"depicted in Figure,3 Ground water was between approximately 14"acid 4 8 <br /> feet;above the screkened interval in monitoring wells MW-1,'MW-2, MW-4"and'MW-1,3 `Ground <br /> water was within the screened intervals of MW-19A,'MW-20A and MW-2IA <br /> i <br /> Advanced GeoEnN irontnerital,Int r" <br />+ 11 11 if'• a k r, 'j - e r ,1 ' Y 1 1 f J h f I f -" ti + , t , , P }' <br /> � , Y 1 s ( •' F !r } , I k.l , ill <br />