|
�T {- % 1.
<br /> _
<br /> ln
<br /> " '� + yam. .kms A - 4. - r = I - �..,.�- '3„-a� :�_ . P-
<br /> G S'�- ^,i.� -I, , -r x.ra r- - °` 4�•*+s w y3 �t 1. F t• t - - -.
<br /> f�471-
<br /> _ r w - . ., s fY'3 ; ...sir» - a: y �""� � � _ �r. `. ' t. _ '�
<br /> r : - > loJune:l998 _. �` - '3r 1 �, A_
<br /> P--
<br /> ,( 5 - I
<br /> AGE NC Pro ect No 96=0229 ". j _y . - �, ��171_ � w� 1 4_
<br /> r• J4. - � _z
<br /> y S
<br /> # .. �} w.�
<br /> a I- rte a -
<br /> �. = Page 4 of 5 4 -r- k — - _ r
<br /> t_ n 1'
<br /> .- j -�j& h �, x — s waw 2° "" 1 *'v i4
<br /> # -f : r.max. �t li`r - ' -
<br /> ` Ground water.' ow direction at the:site(thy area containing wells M W T th ough MW 6)was _� -
<br /> . � esttrnated to_be toward the northeast (Figure 3) ", t ` `F � � �� --.�. � � �)
<br /> '" _ �_. =Based on increasing`ground water.ele�ations at the site,the-ground waterlsurfac�levatjon- =
<br /> t r it;the site is above the slotted screened'iritervaIs in wells MW 1;MW 3.- 4-anci-MWS � � -
<br /> .:
<br /> CL = Therefore,` samples collected frornfhese wells may notU�e represents ; �e of dissolved � `
<br /> k _� 4- ' etrolcum h drocarbn concentrat;ons iii shallow round water A Ott ' �
<br /> F I.FiP Y _ g
<br /> ti -` Vit_.- x `� "._" - -�' '_j*3s " s -6�,` �. ? �"` ' r - 4,r°.
<br /> • TBA was detected for the�f;rst t;me ne. a�wat' sample collected from well=MW 5 „
<br /> _. _ C __- _ } 3 t r: 4- '-.fit-y 5-�^_"�• -,ju�.. . _ .� -
<br /> • Laboratory data and;cotes that the greatest concentrations o€TPH=g ;mpacted-ground water x v� i
<br /> are located-near MW 1 ;MW 2�a_nd M9.W 6 The approximate knolit-wn extent:_of dissolved � -
<br /> T.PH g is depicted n:, figure - The dissolved plume is poorly defined toward the nor[fieast, - I -
<br /> north northwest, east and southeast y - i
<br /> ` �q -• - - %� -3 ,,� ). .yi �j- �, tet , * i�g_ "" "may " 'moi - - .-.I
<br /> tq
<br /> L a = Benzene was d &h-. .' d.tn..safr� les_eo11' ed froni:'wells Iv1VJ 1s MW=2 MW-.3°_ana`lIVIW � .�
<br /> p
<br /> y: df bat
<br /> . - -C
<br /> -m om - j 'i1+ r - -
<br /> ""�° concedtrati6ns+ above theo-,State:_of C I forn�arMaXiinurn Contammant;`Level=fMCI ) foid` _
<br /> drinking wate-I-f 1.0 ppb -The area wtth;the highest concentrations of dissolved benzene ;s.� � ;
<br /> -•s located'near the area of 1vIW 6 jThe�approximate known-extent!of d;!s6lved benzene°ts
<br /> depicted;in Figure 5. M _ t {
<br /> ', Concentrations of toluene were-above the MCL=of 150 ppb in wells:MVIW .1 MW-2 and MW n .a.
<br /> � Ls`� ,' Concertirat;ons of eth}lbenzene were above its MCL of 700.ppb rntiwells MW 1:, MW 2 and
<br /> 'a , - * e �.-�,_ '�' ty `3 c- - 3 j r � �a - - - T FC[
<br /> 41.
<br /> 4+ ` M - 'i - -7- s
<br /> - Concentrations of xylenes were.*above.the MCL of�1,750 ppb in wells MW 11 MyW=2 and- �' '1
<br /> -�F - L . F - �- - -•• .... m 3 .( k" �1' -0'.�--e bise�ssk a-L ,4, . <!4. 1�
<br /> .' ,c� i .. y- - - f z'3tSr. �' v, '�`""�_�.f 3 iF'4 - 's- r,
<br /> i CJttl;ztng EPA methods;8020 and $�60 °concentrationm. s of'MTBE=were,detected above the _` JLJ .
<br /> }
<br /> laboratory reporting.'itm. in samples from wells MW °1 and MW=4 ` -; t_
<br /> f = '4 - r
<br /> I )
<br /> k -..y ,.. - a r ..-a ". �]� _ r rri - j_. -- - - -..s3 : - �'.__•- C'` ''- - �"� # •_`' .:
<br /> 1.
<br /> - s Y • From Nove;nber 1997 to.May 1998, decreasing concentrations of petroleum hydrJocarbons -��� ;
<br /> `, ti have been re-orted:fioni`_MW 3 � ' ��� m _ `� " 7F _� _ �_ , �
<br /> R t-3-} _ -
<br /> �• .From February 1998 to May 1998,;substai�ttal,;dissolved hydrocarbon concentration, � I %,
<br /> _ - � �. Hyl -•$�.^. .'•� !+6F- - ,.. " �' - - - ..:
<br /> 4 _ _- . decreases were obsen ed.from wells MW 1 and MW 2 --Conver5cly, :substantial.Increases -�.- r,.,
<br /> - were ob.14 'served'from MW- The substantial decreases reporfed from N1W�lrarici MW-2.ands. -__
<br /> - t1le:substant;al increase fnk,rom MW-6 coufd be attnbuted to a shift of the dissolved petroleum— - % }
<br /> �' _ hydrocarbon.core area � _ � , _
<br /> s
<br /> s -s--3' -. - -f- - - :e -r �" +^c-yy.. �.: `h r �' r - � Wig- 6'..�t - ` lu r ,� 'e,
<br /> - • ''Duran round water;monitor;n--activities,-the lowestconcentrations ofd;ssolve-tox en �_-,
<br /> �, g`g:. g: yg
<br /> ]�.
<br /> . :•,,� _ =were measured.frorii MW�'1 through- W-3-and M W-6 (dissolved petroleum,fiydroearbon _- -
<br /> f core area),which is suagesfive of aerobic btodegradal;on of hydrocarbons occurr►ng to the ._ _ s���_
<br /> ;,�z�_ "` , - "� Aw
<br /> �,l ih imii oEnv�ronmrnlal Inc" r
<br /> t a r , c y
<br /> - -h, '' t;--h - 4.„� ,:wr•' =-rt`'.�' ��`4M. a �r'- _R ''..' -� _r - .r.o, z w-', _'
<br /> r r - v v �, w - .", , � � e _z: -,`� .,N . •tis= v _
<br /> - . . - - - _ -
<br />
|