UNITE D STATE S ENVIRONMENTA L PROTECTIO

NAGENCY REGIO NI J.F . KENNEDY FEDERAL BUILDING , BOSTON , M A02203-221 1 MEMORANDU

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DATE : Augus t 18 , 199 5 SUBJ : O'Conno r Sit e ;

Remed yChang e J ! On-sit e solven t extractio n t o Off-sit e lan d disposa l j j l ! FROM : Ros s L . Gilleland j j rl TO : Lind a Murph

y Thi s mem o i s i n follow-up t o m ypreviou s mem o t o yo u dat e Jun e 16 , 199 5 (attached) . Th e Superfund Managemen t Revie wCommitte e me t o n Augus t 16 , 199 5 and ha s decide d t o implemen t th e contingenc yremed ya t th e O'Conno r Sit e i n Augusta , Maine . Th e contingenc yremed ychange s th e respons e actio n fromOn-sit e solven t extractio n t o off-sit e lan d disposal . Th e purpos e o f thi s memorandu mi s t o provid e yo u wit hinformatio n shoul d th e solven t extractio n vendor s contac t yo u and o r Joh

n DeVillar s a s theydi d following th e simila r chang e a t th e Norwoo d Site . N o forma l publi c notificatio n o f thi s chang e wil l b e mad e b yth e EP Aunti l th e following hav e occurred : 1 . Yo u and o r Joh

n DeVillar s ar e sufficientl ybriefed . 2 . Ameetin g wit hloca l August a official s t o asses s concern s and th e potentia l nee d fo r a publi c meeting . Necessit yfo r th e Chang e 1 . Technica l Uncertaintie s Th e PRP s hav e long challenge d th e potentia l fo r succes s o f solven t extractio n i n treatin g contaminate d soi l a t thi s site . Thi s soil s a t thi s sit e ar e primaril yclaywhic hadd s I f t o the complexit yo f soi l pre - an d post
- treatmen t . ' preparation , and actua l treatment . Following th e RO D i n1989 , th e Consen t Decre e wa s signe d i n whic hth e potentia l

o f solven t extractio n woul d b e extensivel ystudie d i n bench

and pilot-scal e treatabilit ystudies . Cooperatio n and performanc e o f th e PR P Centra l Main e Powe r i s excellent . A s a resul t o f th e treatabilit ystudies , EPAi n 199 4 issue d and ES D adjustin g th e cleanu p level s from1 ppmcPAH s and PCB s t o 1 0 pp

mt o mee t thes e technica l concerns. . Man y uncertaintie s stil l remai n (pre

- and post-treatmen t handling , mixin g efficiency , spac e limitations ) regarding th e abilit yo f solven t extractio n t o achiev e th e adjuste d levels , however , CM P wa s willin g t o g o forwar d wit h implementin g th e remed yand bega n th e remedia l desig n 2 . Cos t A t 60 % design , CM P requeste d bid s fromconstructio n contractor s and solven t extractio n vendors . Th e resultin g bid s wer e significantl yhighe r tha n previousl yestimate d b y eithe r th e EPAi n th e F S o r CM P a t 60 % design . CM P petitione d EP At o conside r implementin g th e contingenc y remed ybase d o n th e cos t and th e remainin g technica l uncertaintie s whic hfurthe r question s th e fina l cos t o f th e project . Th e attache d Confidentia l Busines s Informatio n tabl e provide d b

yCM P show s th e escalatin g cos t estimate d sinc e th e 198 9 ROD . I n 198 9 th e cos t o f th e entir e sourc e contro l remed ywa s approximatel y$33 0 pe r ton . Quote s fromRC C and C F System s a t th e 60 % desig n ar e now$2000/to n (the treatmen t onl ycos t quote d ar e $l,200/ton) . Lowe r figure s wer e quoted , howeve r the yassume d tha t th e selecte d vendo r woul d eithe r als o b e awarde d Norwoo d o r us e equipmen t from a n on-going projec t schedule d fo r completio n i n 1999 . Summary Th e Sourc e Contro l solven t extractio n remed yi s currentl y estimate d t o cos t approximatel y38,000,000 . Uncertainl yremain s a s t o whe n th e remed ywoul d b e implemente d give n vendo r availability , a s lat e a s 1999 . Th e Contingenc yoff-sit e disposa l remed yi s estimtae d t o cos t$11,500,00 0 and ca n b e implemente d withi n on e t o tw o years .

Th e Managemen t o f Migratio n componen t i s currentl yestimate d i n th e RO D (th

e desig n ha s no t ye t begun ) $800,000 ; howeve r floatin g oi l ha d bee n discovere d whic hmaydriv e u p thi s cos t i n th e desig n stage . i •i i