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A TTOMOTI". _,%SOLU1Z o 5'-16
<br /> Some residual gasoline is„ left behind ,in the area Ithrouzn ankh
<br /> the gasoline ,has. rpercalated; the residue tends to be more concentrated
<br /> in fine) sand ' 'than in the coarser` `materials , (2329) Solubilized
<br /> gasolir.- components may leach from residually contaminated soils for
<br /> long F -ods of time. Induced soil venting has peen demonstrated to be
<br /> a rapid, and efficient, metnod for, removal of gasoline trapped in soils
<br /> following a ' s`pill or leaic (2320) The ` importance of subsurface
<br /> volatilization`,of gasoline coazuonents has also -been demonstrated' in an
<br /> article by,,sYaiiiga (2330 . Volatilization of gasoline;"components from
<br /> - - --residualcontamination --and---�contan--
<br /> mLnatio --;accumulated
<br /> ----- O at--- the----- -
<br /> ground-water ', interface resulted in`�;�detection , o f % gasoline ' vapors, in
<br /> nearby basemenes
<br /> `j ` ` " ,r"i n t 1 Ir,�'�
<br /> The organic player; floating on „the` ground -water- is carried in the
<br /> general, (direction of ground water_fl`ow�,,',,,,At 'tlie`t oil°=water,'liaterface,
<br /> r > r + lr Yr, a,, w , u 1 t�', J�' " t y r tY, !s w„'"w ! r„ „
<br /> some hydracarbo`i�s,,,, are'^,Ieactied accordingi,� o,,Ythe ir ;aqueous ;13saiubility
<br /> t i ❑, 3, r+,S t 1 41 s rr� r(I „iii '}�r r JJ4 i In, �.i'� 4 h', i` ; �4 4 H;6 , � 1 ;
<br /> As,',discussad in,,4chapter,��6�4r,� �1`theafrpol`lution� caused'�byii,,ths,�';hydrocarbon � ,
<br /> 1'r A I,k `� y ,, , I"It 'dr i P V N , 16. v, y r
<br /> phase islmuch;;lass extensLve'� Olos=100s,of`meeers) than�pollution�,caused
<br /> by hydrocarbons , dissol'ved in�``�`,ground` water "(100s-100as
<br /> (1811) . Furthermore. 'the'" pattern o£<<migration of the'Fhydrocaroon phase
<br /> may be very different 'from' --that , of the ground water' Due to
<br /> fluctuations 'in, grouria-water",elevation over time,J the z organic layer on
<br /> e,,, 'l ri % N s 1 aM w �' G�,u i
<br /> top of ,the aquifar3 may' "be trans orzed (into several zones 'where' the
<br /> " 9: •�'N rr'vY'�.,L re,, p, av !k, " �, 1 r,.���, >, ,
<br /> components reoccur , in i thee,; , gaseous_e"phase (able co diffuse n all
<br /> directions.,' Ancludingnq+�„upward) , .''liquid, phase (adsorbed'i? on'tl rock
<br /> Particles', ori rx,sealeda 4under,
<br /> ys dat11 er): or ' ' dissolved/emulsified in water
<br /> ¢,Acv a"Nai1`r
<br /> (1811.2329) �' ' ' „ 4�r� f y j 6
<br /> a r1 " 4
<br /> fI”Pill;I.
<br /> tilh,_M'1^ 4,Y
<br /> Higratioii ,throughl ,soxls',T,may , be; retarded', to �1'a,�minor extents, by
<br /> i , dx I t� PMAV ', " e S. i i ( f a r r
<br /> sorption: � '"Igig�atfon,1,i'sl ',expected' to robe' 'fastast .j through previously
<br /> , . 3 t' +1 i i , I, L +Ib$ R vrl r�, i 1
<br /> contamiiiatad� soils ;where9r,;the' sorptive 'sites may ibe ,unavailable:, on,`,1xhe
<br /> other" hand soil-wafer ,concent, inareasas sorption and 'slaws migration
<br /> °»�cr r, u1,Y r - r [" ! f�P' , ..VI-Ah F 11� s 1 i Y{/ " 1�'F;, ! , ,n r 3
<br /> ,of 1lhydtocarbons!,, *In*f�is sure d`�-roak.r the mLgrat�tont.-of Hydrocarbons'' is
<br /> anteh„lass `uni'farm than",in"porous'soils. PreferenCial,Yspreading through
<br /> v y , .
<br /> crevices: sometimes r changing," Atha,' direction ,of ,flow.” may ` occur.
<br /> Determination of 'the potential' ground-water contamination in ` fissured
<br /> rock is thus very difficult ,(1811) .
<br /> q_
<br /> — n The water-soluble portion of gasoline was shown to be almost
<br /> 'entirely aromatic (87-94%), ;even though ,the product, itself was almost
<br /> 50%' aliphatic. the aliphatic, hydrocarbons, either ,'volatilized or were
<br /> essentially not, waLe]C-soluble (1849) . Inideep. saturaced SOLIS with no
<br /> soil air. some low molecular weight aliphatics may be dissolved in and ,
<br /> transported with ground water: ,however, the light aromatics represent
<br /> the greatest threac`of contamination to ground-water supplies.
<br /> Intrammary„ the physical distribution of gasoline contamination
<br /> „,affects its impact on, and removal from, the soil environment. Lateral
<br /> spreading{ along the 'surface increases the initial contaminated area
<br /> while facilitating evaporative removal of the Low molecular weight
<br /> hydrocarbons. Subsurface release or vertical p'enetracion mediated by
<br /> ,ti 1
<br /> 6/87
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