~f
Superfund . t„f~{~:}:P9:~'f
Re.cord of DecIsion:
&EPA
Milltown, MT
(Supplement to 04/14/84 ROD)
- -- .' .. ",-----:."'---.,.~--
..._;:.:'3:;.,.::~~~~;,
-------
Ttt;t1NI\OAL. "crun, ,,"'....
(PlHJ~ ntld IIIStIVCliollS all ,h~ 'tll~n~ Mfon compllli",)
1. AEPo,n NO. \2. 3. RECIPIENT'S A'CCESSION NO.
EPA/ROD/R08-85/002
.. TITLE ANO SU8TITLE 5. REPORT OATE
SUPERFU1~D RECORD OF DECISION Auaust 7, 1985
Mill town, MT (SuppJ..ef.\enta1 ROD) 6. PERFORMING ORGANIZATION CODE
- - .
7. AUTHORIS) 8. PERFORMING ORGANIZATION REPORT NO.
if. PERFORMING ORGANIZATION NAME AND ADDRESS 'o. PROGRAM EL.EMENT NO.
n. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADORESS 13. TYPE OF REPORT AND PERIOD COVERED
U.S. Environmental Protection Agency Final ROD Report
401 M Street, S.W. 1.. SPONSORING AGENCY CODE
Washington, D.C. 20460 800/00
1IS. SUPPL.EMENTARY NOTES
U. ABSTRACT
The Mil1town Reservoir Sediments site is located in lolissoula County, Montana.
The site is adjacent to the Mi1ltown Dam where the Big Blackfoot River joins the
Clark Fork River. Constructed in 1906, this hydroelectric dam formed a reservoir
that trapped sediments from mining, milling and smelting operations in the upper
Clark Fork valley. During the years since construction, the reservoir storage has
been almost totally filled with arsenic contaminated sediments. In May 1981,
Milltown's four community water supply wells were found to be contaminated with
arsenic and other heavy metals. The highest arsenic levels measured have been
between 0.54 to 0.90 milligrams per liter (mg/l).
The original ROD was signed in April 1984 approving the installation of an
alternative water supply, and the flushing of the plumbing system of each house to
remove suspended materials from the water system. This supplemental ROD approves
the replacement of household water supply appurtenances and on-going sampling of
residential water systems to fulfill the intent of the original ROD. I
.
,
17. KEY WORDS AND OOCUMENT ANAL.YSIS
.. DESCRIPTORS b.IDENTIFIERS/OPEN ENDED TERMS C. COSATI Helli.Gr. ,..:' t
Record of Decision \
101ill town, MT (Supplemental ROD)
Contaminated Media: gw, soil i
Key contaminants: heavy metals, arsenic :
!
i
I
..-t
19. SECUR1T,,: CL.ASS, nlls R,'p,,,,, 21. NO. OF PAGES .
18. DISTRIBUTION STATEMENT '
.
None 1 i
20 SECURITY CL.~SS ITllis p,J.~.': 22. PRICE .
.
None I
:
I'. '.111 2220-1 (Rn. 4-77)
PltlEYIOU5 EOIT'ON.5 OBSOLETE
.. -~.~~t."~'::~
-------
INSTRUCTIONS
,.
REPORT NU18ER
Insert the EPA report number u ilappears on lhe COVer of the publil:ation.
LEAVE BLANK
2.
3.
- -
'0 -
RECIPIENTS ACCESSION NUMBER
Relel'Yed for use by ead, ~port recipient.
nTU AND SUBTITLE
Tide should indicate clearly and brieny the subjC\.t covera~ uf the report. and be disl'lay~'d ,,,olllin,'nily. S.'I ,"hli"~', if """.1, III ~lIIali.',
Iype or otherwise subordinate it to main title. When a report is rrepartd in moR' Ihan on.. volullle. rep'allhe rrilllary tille. a.ld v.II:lIIW
awnber and include subtille for the specific title.
...
..
REPORT DATI
Łacta report shall carry a date indica tin, It least month and yeu. Indkate Ih.. hasis 011 \II'hidl il "as ,,'Ie~.t,'d (I'.,.. .kI'I' III ;UIII'. JiI'I' III
."ptONI. ."01 pnptl18lion. "c.).
"RPOR"NO ORGANIZATION COOl
Lea.. blank.
..
7.
AUTHORCSt
Give name(s) in c<)nvcntional order (John R. IXN, J. Rob..'" Dot'. ("I'.J. List aUlhor's amlialloll if il .Ii'T..,s f"'l11 Ih., I"",f(lrlllill~ ,,'~oalli.
ulion.
..
"'R'ORMING ORGANIZATION REPORT NUMBER
Inaen if performin. orpnization wishes to assi", Ihis number.
I.
"RPORMING ORGANIZATION NAME AND ADDRESS
Give name, street. City. state. and ZIP eod~. Lisl no more than two lI:vel5 of an or~ani/aliunal hir...rdIY,
'o. PROGRAM ELEMENT NUMBER
Use the propam elemenl number under which the report lI.as prepared. Suburdin"'h: numbl:r, III;.), be ill..!...",,, III 1';II~'II'h~'"",s.
n. CONTRACT/GRANT NUMBER
Insert conUlct or pant number under whkh report wo prepared.
,2. ~ING AGENCY NAME AND ADDRESS
Include ZIP code.
,3. TYPE OF REPORT AND PERIOD COVERED
Indicate interim rmal. el",. and if applkable, dates covered.
'4. 88ONSORING AGkNCY CODE
Insert appropriate code.
,I. SUPPLEMENTARY NOTES
Enter Informalion not included elsewhere but useful, such as:
To be published in. Supersedes. Supplements. ~tc.
18. ABSTRACT
Include a brief (200 words eN less) factual summary of the mosl 'llInll'kant information ,ulI!aln'"'' III 110,' I "1'"11, II Ih~' "'1,".1 '''"1"",, ..
Ji&nillcant bibliopaphy or literalure survey. mention II here.
Prepared ill .:uopcratiun wllh. I r;...,lallllll ..I. l'r':"'"I~'" ;II ~'''"'''h'lh " ..I.
n. KEV WORDS AND DOCUMENT ANAL VSIS
(a) DESCRIPTORS. Sele':l from Ihe Th"'l;jurus of tnglllec:rir.... ",nd S",'IIIIII, , C'III, the propcr "ullt"r"",J 1,'/111' th..! hklllll~' Illc OI;'llIr
concepl of the research and are sufficienlly ~peelfic and pr~.:ise 10 be u",u ..' IOu'" .:nlrae, "ur ';lI.lI..~IO!!,
(b) IDENTIHERS ,~:'IiD OPD..I:~DED TERMS . Use Idenllfi~n for prOle.:! n.lOl,', .0Je lI;lmn, "4u1prncnl ""'I~n,'t"". ,'I~' l',,' "I'C/l'
ended terms wntt~n in d.:~.:raplor form for those ~ubJects for whleh no \Ie', nplur ",,,,,.
(c) COSA TII'IUD GROUP. Held and 1!I0up Iss!Jnments olrc to b-: Iilkl.'n hum Ih~ I Y#I$ ('OS" II Suh,~,,, ('.Ilq!II'y 1.ist. Sinn' 1111.' 01,1'
jority ofdocumenuare multidiSC:lplinary in nature.lhe Primoary I ich1;C;roup a"lgnm':IlIf" 11.111 be '1""111, dl"I"ltn~'. ar~'a ".. hUIII.,n
endeavor. or type of physi.:aJ object. The applicationCSI lI.'iII be .:ru)~''':lcrcn.:ed Wllh ''''''1111;1') 11,'hl '( .rllul' "'''VIIIII,'III, 111;/1 \0 1111. ,II. '\\
the primary postingu).
,I. DISTRIBUTION STATEMENT
Denote releasabilil)' to the publil: or linlllJlion for rea'un~ uther than \\:'Ullly fur C\ilnlplc "Rd,'",,,, I 1111111"...1." { ,,~. ..ny .1\;III,""ltl~ ,,,
Ihe publil:. with addrC:b ",nd plll.'e.
"..20. SECURITY CLASSIFICATION
DO NOT submit cl.mlflCd rc:purlS 10 Ihc :o.i"'lionill Tel.'hnll.'illinformallun 'erv.~I.',
2'. NUMBER OF PAGES
Insert the tOlal number of pages. indudlll~ rhl, one and unnumbered pall':'. hul ",dullc 1l1,lrabuliun 1t,1. I' ",ny.
22. PRICE
Insert Ihe price set by the National fed:m";lllnform.luon S,rvILL' LO' II.. C;u\C,nllll.'lIll"lntlng OffiLl.', II kncmn,
E PA ,.,... 2220-1 (R.... 4-77) IR....,n)
-------
SUPPLENENTAL RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
ADDITIONAL MEASURES TO REPLACEMENT POTABLE WATER SUPPLY
Si te :
Milltown Reservoir Sediments, Milltown, Montana
Analysis Reviewed:
I have revie~ed the following ~ocuments describing the necessity for
additional measures to supplement the Record of Decision selection that was
decided on April 14, 1984, for this site.
Data reports from the testing and flushing of household water systems
conducted under the remedial action approved in the 4/14/84 ROD.
Recommendations by the Montana Department of Health and Environmental
Sciences (MDHES).
'~orandum from John Wardell dated August 6, 1985 with attached staff
report ti tled "Supplementary Analysis of Mill town, Montana Drinking
Water Supply. II
Description of Selected Options:
Replacement of household water supply appurtenances that remain a
source for persistent arsenic and heavy metal contamination as
described in the support documentation referenced above.
On-going sampling of individual residences to insure that the sources
of contamination have been removed.
Declarations:
Consistent with the Comprehensive Environmental Response, Compensation and
Liability Act of 1980 ( CERCLA ), and the National Contingency Plan (40 CFR
Part 300), I have determined that the replacement of water supply
appurtenances and on-going sampling of residential water systems is necessary
to fulfill the intent of the original ROD and therefore are cost-effective
remedies, and that they are part of a key action necessary to provide adequate
protection for public health, welfare and the environment. The State of
Montana has been consulted and agrees with the approved remedy. I have
determined that this action is appropriate when balanced against the need to
use Trust Fund money at other sites.
The State is conducting additional remedial investigation/feasibility
study to evaluate the extent of contamination. If additional remedial actions
are determined to be necessary, a record of decision -"11 be prepared for
approval of the future remedial action.
on.
R~gional
.'1ItS
me
. .~.'~",~..-...".;:.r::;.~~:'
. " :;~.: \:; ,"
------- |