United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/ROS-ae/S**"
June 1986
SEP A
Superfund
Record of Decision
-------
. -.'. ......""" "" -" ~.- ,"- '." -.". .,-." ,,,,,,".'
.' "'. . .-- -r'-
\
TECHNICAL REPORT DATA
(PleaJt 'e~d ',utNet/O"S 0" the ,tvtnt bt/tNt co,",,/ttml/
,. fIIl~OfllT NO. 12. 3. "'ECII'tE...T'S ACCESSIO'" "'0
EPr../1:~nn/ROS-86/03 8
4. TITL.E AND SuITITL.1 5. fIIE'OlilT OATE
ENFORCEMENT DECISION DOCUMENT Mav 30, 1986
-- Reilly Tar & Chemical, MN s. 'EfII-=OfllMINC OfilCANIZATION cooe
(Second Remedial Action)
7. AuTMOAISI 8. PEIII-=OfllMINCi O"'CiANIZATION "'EPO"'T '<0
e. 'EfII~OlllMING OlilCiANIZATION NAME ANO AOO"'ESS 10. 'IIIOCi"'AM EL.EMENT NO
11 CON'TfilACT/CifilANT NO
I
12. SPONSOlillNCi ACiENCY NAME ANO AOO'-ESS 113. Type 0-= "'EPO"'T ANO PE"'IOO COvEQE:
U.S. Environmental Protection Agency Final ROD Report
401 M Street, S .W. I.. SPONSOlillNCi ACiENCY COOE
Washington, D.C. 20460 800/00
15. SU"L.EMINTAAV NOTES
,S. A8ST"'ACT
The Reilly Tar and Chemical Corporation (RTCC) site occupies 80 acres in St. Louis
Park, Minnesota. The. Republic Creosote Works, which operated the site between 1917 ann
1972, fractionalized coal tar into various oils and produced creosote. The wastes
resulting from this process polluted the land surface of the site and the underlyina
aquifers. The primarv contaminants of concern include: PARs and phenols.
Th~ Remedial Action Plan (RAP) attached to the Consent Decree prescribes the
followina remedial actions, remedial investigations and feasibility studies to be
completed over the next five years: Restoration of drinking water supply and water
quality by construction of a Granular Activated Carbon (GAC) system at St. Louis ParI<
We 11 s (SLP 15/10). Thi.s task has been completed by the RTCC and is in the start-uo
process: monitoring and continqency treatment of the Mt. Simon/Hinckley aquifer:
monitoring, pumpina and treatment of the Ironton/Galesville aquifer: monitoring, pu"r>i~(
and treatment of the Prairie du Chien/Jordan aquifer until drinking water quality is
uniformly established within the area of gradient control: monitoring and continaent
action for the maintenance of drinkinq water quality in the St. Peter aquifer:
monitoring, pumping and treatment of the Drift and Platteville aquifers: monitorina,
pumping and treatment of the source material in the Glacial Drift aquifer and in w~ll
WZ3 in the Praire du Chien/Jordan aquifer: capping and tilling of exposed hazardous
'5"'''' ~ttached Sheet'
17. I(EY WOlilDS AND DOCUME...T A...AL.VStS
a. DESCA.,TOfilS b.IOE...TII"E"'S'OPE-" e'
-------
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'..'".' ....-.--., ,- ~,.',." -. ,.
.:...,..-',~_:,~~'-'.~..:..t::-;'.' """"""",,'...~-_..--,""'_'..a_'. . ,.,1", ....." .....,...,~....--....,_.~..------.,-~-~.
EPA/ROD/R05-86/038
Reilly Tar , Che~ical, MN
(Second Remedial Action)
16.
ABSTRACT (continued)
wastes in the vicinity of the bog, south of the site: discharge of hazardous
wastes to a sanitary sewer for any contaminated material excavated and
dewatered: further subsequent investigation in the vicini tv of the site to
implement deed restrictions for current and future land use in the areas of
contamination: further RI/FS's to determine the areal extent of, and remedy
for the contamination in the Northern area of the Glacial Drift aquifer
adjacent to the site: further RI/FS's in the St. Peter aauifer as necessary
to implement the remedial action presented to protect drinking water
-------
Enforcement Decision Document
Remedial Alternative Selection
Site: Reilly Tar and Chemical Corporation
St. Louis Park, Minnesota
Documents RevieWed
The following documents have been reviewed by the United States Environ-
mental Protection Agency (U.S..EPA), Minne$ota Pollution Control Agency
(MPCA) and the Minnesota Department of Health (MDH). These documents
describe (1) the problem at and beneath the Reilly site caused by the
wastes generated by the creosote production and wood-treating process
used by the Reilly Tar and Chemical Corporation, (2) the potential health
risks associated with ingestion of these compounds found in the ground
water, and (3) the various remedies evaluated to cost-effectively mitigate
t~e release of contaminants:
(1) MSoil and Ground Water Investigation, Coal Tar Distillation and
Wood Preserving Site, St. Louis Park - Phase I Report. prepared
by Barr Engineering Company, May 1976.
(2) .Soil and Ground Water Invest~gation, Coal Tar Distillation and
Wood Preserving Site, St. Louis Park - Phase II Report., prepared
by Barr Engineering Company, June 1977.
(3) .H~alth Implications of Polynuclear Aromatic Hydrocarbons. in St.
Louis Park Drinking Water" prepared by the Minnesota Department
of Health, November 1978. .
,
(4) "Progress Report: Investigation of Coal Tar Derivatives in Ground
Water - St. Louis Park" prepared by the United States Geological
Survey (USGS), April 13, 1979.
(5) "Field Investigation of Uncontrolled Hazardous Waste Sites, Cost
. Estimates for.Cleanup of Contaminated Ground Water and Soil at .the
Reilly Tar and Chemical Company Facility, St. Louis Park Minnesota"
prepared by Ecology and Environment, Inc., 1980.
(6) .Prelimina~ Evaluation of Ground Water Contamination by Coal Tar
Derivatives, St. Louis Park, Minnesota. prepared by the USGS, January,
1981.
(7) .Report 0" Drinking Water Treatment and Remedy Evaluation for St. Louis
Park, ~nnesota. prepared by Eugene A. Hickok and Associates, Inc.,
Aprl1 1981.
,
(8) .Study of General Water Contamination in St. Louis Park, Minnesota"
prepared by Eugene A. Hickok and Associates at al., November 1981.
-------
(12)
-2-
(9 )
"Degradation of Phenolic Contaminants in Ground Water by Anaerobic
Bacteria: St. Louis Park, Minnesota" prepared by Eilich, Goerlitz
Godsy and Hult, USGS, November 1982.
(10) "Evaluation of Ground Water Treatment and Water Supply Alternatives
for St. Louis Park, Minnesota" prepared by CH2M-H;1l, 1982-83.
v
(11 )
"Recommended Plan for a Comprehensive Solution of the Polynuclear
Aromatic Hydrocarbon Contamination Problem 1'n the St. Louis Park
Area" prepared by Envi ronmental Research and Technology, Inc. for
the Reilly Tar and Chemical Corporation, April 1983, plus Errata,
June 27, 1983 and November 27, 1984.
"Assessment of Ground Water Contamination by Coal Tar Derivatives,
St. Louis Park Area" prepared by M. F. Hult, USGS, Open File Report
84-867, 1984. .
(13) "Record of Decision, Remedial Action Alternative Selection" prepared
by the United States Environmental Protection Agency (U.S. EPA),
June 6, 1984.
(14)
"Evaluation of Granular Activated Carbon for the Removal of Polynuclear
Aromatic Hydrocarbons from Municipal Well Water in St. Louis Park,
Minnesota" prepared by Calgon Carbon Corporation, September 10, 1984.
"Ground Water Ftow in Pra'irie du Chien-Jordan Aquifer Related to ,
Contamination by Coal Tar Derivatives, St. Louis Part, Minnesota"
~repared by J. R. Stark and M. F. Hult, USGS, 1985.
(16) "Pollutant Source Identification Study" prepared by Acurex Corporation
for the U.S. EPA, September 1985.
(15)
(17)
(18)
(19)
"Review and Evaluation of Ground Water Contamination and Proposed
Remediation at the Reilly Tar Site, St. Louis Park, Minnesota"
prepared by Dr. James W. Mercer, Geo Trans, Inc., December 1984.
"Reilly Tar and Chemical Corporation Refining and Wood Preserving
Operation at St. Louis Park, Minnesota" prepared by Dr. Warren S.
Thompson, December, 1984.
.Summary of Expected TestiMOny on Principles of Contaminant Transport
in the Ground Water System .rtth Application to a Coal Tar Derivative
Contamination Probl.., St. Louts Park, Minnesota- prepared by Dr.
Hans-olaf PfanntuCh, December, 1984.
(20) Progress Reports of Clean-up of Well W23 and Well W10S produced by
Eugene A. Hickok and Associates, 1982-1984.
(21) Soil Borings and Chemical Analyses produced by the GCA Corporation,
December, 1984. .
(22) Analyses of Ground Water'and 5011 Samples by Midwest Research Ins~itute
. under contract to the U.S. EPA, 1981.
(23) Analyses of Benzene Extractables and Soil Contamination Profiles about
- the Reilly-Site produced by David Crisman, MPCA, in a memorandum to
Paul Bitter on January.. 14, 1986.
-------
.., - ".", - .... , ':t "'. '~.,. - ."' - . .'- '.'", ..'~ '"'. ,~"... ; . ,". .. .', ;," "". -.. '> -.
, .', J~'.~- .'~,-...' :_:..' ......... : ::..t '.'" -.. ~~:. ~"..- .--.., ..:;......... -1..-..", .';.I'!<"";' _>":,d....L.-:~~.,I":..-J.':"":;.~...~'~':: .:.' ~\-~.;..~.,..1~...~t.,,::,,...5:... .1..:....._.r..:.&..J.;,.'L~_~I.,:\.,,-,~j).. :...:..:.. ..::.\. ,
-3-
Description of Selected Remedy
The Remedial Action Plan (RAP) attached to the Consent Decree, prescribes
the following remedial actions. remedial investigations and feasibility
studies to be completed over the next S years and to be operated until
cessation criteria enumerated in the RAP are satisfied.
(1)
(2)
(3)
(4 )
. (5)
(6)
(10)
(11 )
Restoration of drinking water supply and water quality by construc-
tion of a Granular Activated Carbon (GAC) system at St. Louis Park
Wells (SLP 15/10), i~ accordance with the June 6. 1984 Record of
Decision. This task has been completed' by the Reilly Tar and
Chemical Corporation and is in the start-up process;
Monitoring and contingency treatment of the Mt. Simon/Hinckley
aquifer to maintain drinking water quality;
~onitor1ng. pumping and treatment of the Ironton/Galesville
aquifer to protect the deeper Mt. Simon/Hinckley aquifer;
Monitoring. pumping and treatment of the Prairi- du Chien/Jordan
aquifer until such time that drinking water quality is uniformly
established within the area of gradient control;
t
Monitoring and contingent action for the maintenance of drinking
water quality in the St. Peter aquifer; .
(7)
"'onitoring. pump1.ng and treatment of the Drift and Platteville
aquifers to protect the down gradient use of the aquifer and the
deeper St. Peter aquifer;
Monitoring, pumping and treatment of the source material in the
Glacial Drift aquifer and in well W23 in the Prairie du Chienl
Jordan aqu; fer;
(8)
Capping and filling of exposed hazardous wastes in the vicinity
of the bog. south of the site, in accordance with the U.S. Fish
and Wildlife and U.S. Environmental Protection Agency regulations;
Discharge of hazardous. wastes to a sanitary sewer for any con-
t..inated ..tertal excavated and dewatered for the purposes of
construction of an intersection in the vicinity of the bog;
(9)
Further subsurface investigation in the vicinity of the site, to
i8pleMent deed restrictions for current and future land use in
the areas of contamination;
(12)
"
Further Remedial Inyestigations/Feasibility Studies to determine
the areal extent of, and remedY for the contamination in the
Northern area of the Glacial Drift aquifer adjacent to the site;
and .
Further Remedial Investigation and/or Feasibility Studies in the
St. Peter aquifer as necessary to implement the remedial action
-------
-4-
All of the above actions will be implemented in accordance with the
relevant environmental laws and regulations. Cessation of the above
actions will be decided by the Regional Administrator based on criteria
already established or on criteria that may be proposed in the future.
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 detennined that this Remedial Action Plan for
the Reilly Tar and Chemical Corporation Site will produce cost-effective
remedies that provide adequate protection of the public health, welfare
and the environment. The State of Minnesota has been consulted and agrees
with the approved Remedial Action Plan. In addition. the action will
require future operation and maintenance activities to ensure the con-
tinued effectiveness of the remedies. These activities will be con-
sidered part of the approved action. Settlements have been reached
between EPA, the State, the City of St. Louis Park, the City of Hopkins,
Oak Park Village Associates, the Housing and Redevelopment Authority
of St. louis Park, Phillips Investment Company, .and Reilly based on
the Remedial Action Plan.
t
I have also ~etennined that the actions being taken are cost-effective
alternatives when compared to the other remedial options reviewed.
DA
4a-; fI
a1 Administrator
Region V
United States E vironmenta1 Protection Agency
Attachments:
Summary of Remedial Alternatives Selection
Record of Decision. June 6, 1984
Consent Decree
Remedial Action Plan
-------
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/',-' - ... -. . ..< .~..- -' '. ..' -- ..
-5-
Summary of Remedial Alternatives Selection
Reilly Tar and Chemical Corporation
St. Louis Park, Minnesota
Site Location and Description
The Reilly Tar and Chemical Corporation site occupied 80 acres of land located
in St. Louis Park, Minnesota (F'igure 1). A copy of a site map is attached
(Figure 2). The plant site, called the Republic Creosote Works, ~as located
~est of Gorham, Republic and Louisiana Avenues, south of 32nd Street, east
of Pennsylvania Avenue, and north of Wal ker Street. The company no longer
owns the land; the City of St. Louis Park purchased the land from Reilly
in 1972 and it is currently owned by the St. Louis Park Housing and Redevelop-
ment Authority. The City is contiguous to the City of Minneapolis and
exhibits a similar population density. Currently, the site is a park ~ith
a portion of it developed with condominiums. It is located in the midst
of a residential area with some small industry.
Site History
The.site history is summarized in Appendix A, Record of Decision for con-
struction of a Granular Activated Carbon System at St. Louis Park W~lls
SLP1S and SLP10. The following supplements that infonmation.
"
Reilly Tar and Chemical Corporation produced creosote from its coal tar
distillation process although for a few years pentachlorophenol (PCP) was
used as a preservative. Reilly primarily treated railroad ties, timbers,
poles, piling, and heavy duty products. PCP was commonly used on mill~ork
or wood where a clear paintable surface was desired. It is not used
for heavy products. Throughout the Remedial Investigations, PCP was not
found in the soil, ground water, or in the coal tar found in the well bore
of W23 on site. The wastes discharged or spilled on the site are predomi-
nantly polynuclear aromatic hydrocarbons (PAH) and phenolics. Discharges
from the refinery went overland and through conduits to a bog south of
the site. The pathways and sources of contamination are discussed, in
detail, later in this document.
The cont..ination of the aquifers beneath the site occurred through spills
of coal tar product that eventually migrated down Well W23 on-site and
contaminated Multiple aquifers, and through leachate generated by discharge
of waste water oyerland into a bog south of the site. This leachate from
the bog cont8l1nates the surficial aquifer (Drift) after which the contami-
nation either leaks downward to the Platteyille aquifer or is conveyed
through the Drift aq\l1fer to the Plattey'ille and St. Peter aquifers
through the geological pathways that exist downgradient from the site.
Over the years 1917-1970, millions of gal"ons of waste water were discharged
to the bog. on an annual basis. The bog, therefore, serves as a continuous
-------
.: ',.", " . ~',' ..,'.
'.'~ -'- ','.. ,
.,:~;". ,;....
'...~. ';"-_.!" .). !r.''''..';>J.-~.z;..l"~'.:-;'''W';''...:.!t,~r...,~~;;''';. i.'A..:t:. .~'.I:':"'..;'. ..~';,..LJ"":I:I ~_.J:.'G;..::..!""~:~::.. .~ .~:";':"'.. ,:;,.'o..:~.".. . ". .~..~ '~:;"'-''':'- .,.. ~'- ~ ." ..' ,""'~~', ."",'--'
FIGURt
1
-------
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.'. . '.. .,' ".,~',: . ..',":'
" " "
, :'~ " '~ '. "., '" -, :
.', ..- "
-_. -.~,'_'."'-:"~..'.-. :_~,-",-,:"_:",',,,""'i'~". ,.~.-.:...._.,~..:...,,~,_:::-...:.. .,!'.''''''' ..'~'
;. '. ., - ........ ' :.:::. .;..: .". '. -.;'." ".,-
-6-
Current Site Status
This is also surrmarized in Appendix A. The only substantive addition to
the appendix that should be mentioned here is that the City of St. Louis
Park Housing and Planning Commission plans on developing more of the site,
which is currently used primarily as a park, and the City continually
stores old timber and contaminated soil excavated on the southwest corner
of the site; below the surface. These soils were excavated during the
development of the site, and are further addressed in the Alternatives
Analysis of this EDD and in the Remedial Action Plan, which is part of the
Consent Decree, implemented by Reilly. Appendix A addresses the contamination
in the Prairie du Chien/Jordan aquifers. This section will surrmarize all of
the contamination measured in the aquifers and on the site.-
The-aD acre site once owned by Reilly is primarily park land today, but
contamination exists throughout the subsurface of the site although not
to the same ~agnitude as the contamination in the bog. The receptors on
site would be individuals who build foundations into the depths of the
contaminated subsurface. For this reason the MPCA has instituted procedures
to monitor and inspect areas under development at the site and to require
proper disposal of contaminated earthen material. This will be further
discussed in the Screening of Alternatives sections. The largest amount
of potential receptors are those who may ingest the ground water near the"
site.
t
Since the City provides municipal wells finished into the St. Peter,
Prairie du Chien/Jordan and Mt. Simon/Hinckley aquifers, these wells can be
monitored for cont~~inat;on as discussed later.
The physical/chemical parameters of peat allow for it to significantly
adsorb large amounts of coal tar compounds. Nevertheless, a continuous
release of contamination occurs from the peat deposits south of the site.
Evaluation of the chemical analyses shows that contamination in the Drift
aquifer can be measured at least over one-half mile east of the site. There
are three major pathways for contamination of the aquifers: (1) leachate
into the Drift from spills and precipitation into the ground water over the
years, (2) drainage to the south of the site to surface water ponds and
Minnehaha Creek, and (3) W23, the "well that contained coal tar compounds
(solid and organic phase) and which conveyed approximately 15 gpm from the
St. Peter aquifer to the Prairie du Chien/Jordan, contaminating that aquifer
with solubilized PAH caBpounds.
Soil Contuinltion"
Soil borings collect~at various depths and measured for Benzene Extractable
Organics provided a visual and analytical description of contamination found
beneath the vicinity of the site. Contour lines were produced to display the
approxi~ate locations where the chemical data exceed-the backgound concen- .
tration of 500 to 800 mg/kg, dry weight, of benzene extractable organics
~easured in uncontaminated peat found at the site. The peat generally un-
-------
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, ,. ' .:. . .'. .;~...: ~ '. '. ..
; '.t.l"'I".""'I~ - ,..:'"-;;";.'::...::;.:::.~~..)',_..(.!{-:'.::...~.';:~'-:.~:.~,.:->:" ,.:'~,;.,'..':\'.,;':',:J,:,~ ...~\~.,.:-':~,: ::~;i:,~i". i. '.;..~~.~' ..1¥;":.'.;-I' ~'.,"; ';~...-A' ,::.,~..... ,:.',/:':~:_~" '.......,: " :..: :";..' :;,.~.~' '.. '...., , .
,- ..'...,. ~ --., - ' ....
-7-
Review of the information shows that most of the contamination is above the
10 foot level within the site boundaries. The bog, south of the site, for
the purpo~es of this EDD is bounded by Walker Street to the north, Lake
Street to the south, the extension of Louisiana Avenue to the east and the
intersection of an imaginary line extending south of the western boundary of
the site where it abuts Walker Street with an imaginary line extending westward
from the Western-most terminus of Lake Street as shown on Figure 2. ,The area
of contamination within the bog remains somewhat constant with depth. The
deposit of creosote contamination serves .as the source of contamination to
the surficial (Glacial Drift) aquifer. This volume of contaminated earth was
first estimated at 400,000 cubic yards. Further considerations using data
collected from local monitoring wells extend the depth of contamination subs-
tantially such that as much as 800,000 cubic yards of earth may need excavation
and proper treatment or disposal in a RCRA compliant landfill. The plant site,
by comparison, shows most of the contamination to a depth of 5 feet with only
small areas showing contamination at a depth of 10-15 feet.
The adverse effects due to these deposits of creosote wastes are the associated
health risks manifested from exposure to these compounds. Exposure can occur
by excavating the soils or by drinking or bathing in water that has been con-
taminated by leachate emanating from the site. The remedial investigations
and remedial actions prescibed for this site and for the surficial aquifer t
are based on limiting the exposure to these compounds. Therefo,re, the City'
of St. Louis Park has the responsibility of complying with laws and regula-i
tions pertinent to the disposal of hazardous wastes found at the site and -
must consider the appr,priate land use for this area. Si~ilarly the U.S. Fish
and Wildlife Service will partake, with the other agencies, in overseeing
and reg'Jlat1ng any backfilling, excavation or dlteration of that part of the'
bog which is construed as a wetland. The migration of contaminants in t~e
Glacial Drift Aquifer will be mitigated by a pump~ut system in order to pro-
tp.ct downgradient users. These alternatives are fully discussed lat~r in
this EDD.
Aquifer Contamination
Coal tar released from the site has contaminated four aquifers located beneath
the site (see Table 1, Figure 3 and Figure 4). The aquifers that are being
and will he studied under the Remedial Action Plan are
the foll ow; ng:
TABLE 1
Hydrogeology Below the Reilly Tar and Chemical Corporation Site
Aquifer
Approximate
Depth (ft.)
Use
-
Upper Range of
Contamination
(Total PAH)-
,
(1 ) Drift/
Platteville
0-90
Private/Industrial
wells
1000 ug/l off-
-------
DEPTH BELOW
LAND SURFACE I
IN FEET
100 -
200
300 -
400 -
500 -
600 -
700 -
800.
MY DROGEOLOGIC
UNIT
0-
Drift
Plotteville aQuifer
Glen.ood
confinin; bed /
St. Peter
aquifer
BOlal St. Peter
confinin; bed
Prairie du Chien-
Jordon aquifer
St. Lawrence-
Fronconia
confinin; bed
.8~. . ;... '. °0
::': .~; 0,..
, ~. .8 8...
0, e.::,_;:
. . . . . . . .
',,'0 "
.',
"',',
i= ~ ~:.~
- - - -
___e.
:a = s ---
-----
, ,
0" "",..,,
.' . ~:: ': :,,' ~:. :,"
':),:i){?'::
-- - ~
~ -".-
"S:2'
:'~"~"~.
.~:~..~
.'~.-::.
=:=&~
- - .
Iroftton-Golelvilt. ' .
aquifer '
-----:.
-.-.-.-.:.
:::::::~
~-::-------
..~------:':
~~----.:--
~-:-:-:-
--~-----
---...
-.-.-.-.
------~.
-.-.-.-.
Eau Claire
eonfi nino bl cI
Mount SiI"on-
100. Hlftekll' ...uifer
1000 - '
:. .:.::.:', ':.:'
,:};.::;{;)".','
"--LA . I Sand
-cIa - Silt
DePOlltS Till
Limestone
Shale
Sandstone
Silt~ Sandstone
Li""'tone and
Dotomite -
Sand'ton.
t
.
Sandstone
Shale
S.ncI'tOM
FIG.3.' GENERALIZED STRATIGRAPHIC COLUMN BASED
ON WELL LOGS FROM W 23 ON SITE
(AFTER NUL. T A"D SCHOENBERG ..84)
-------
,'".. .-.'- "--".. '-'"" P-.'-."".. ..." ''''.,.....--...
..~T,."~_~-_....... --,-,_.~~-,-~...- _T___- n., .-..-".-.
.T,CC ...", 5...
51 ...., ..".... -
GI'"'''' ,"'... C."""""I ...
51 ....' ",,".'
. ~..,. ... Cflt8....I8t.... ........
-.. L.IWf."."'."'C"''' C...,....... I.e
.. "......Ga...".... ....".'
-- b.. c:.... c....,,,."1 ...
I
J" ..III8ft.---- """"
t
0--., 1eoI88I" Drtt\.~...... ........
1
~
".8
'- II ~""."8fII8Ao8 CeM."'", .ee
- ......-.G...." ,.,...,
.... c..... C.....-. ...
Mt .....,.......... .......'
....... '...",. ... Or",........ ... .........
Figure 4 .
-------
, ... .... - , ..... "~J '. - ,~'.H_. . "-'-'" - . .......- ,"'...'" - -..... .~.. - --....-.. """"~'-"'-'""''''''-''' ".- .~....,._.......... '-' -..~... ". .........-,..- _0...'" --.. .,.. -.". .......~,. """'-.-'. ".,~ .". I"~ .1" ''''''.'.. ~....",.".._.........................""U.,'o'o:U. "'~.:.>-....._'.,
-8-
(2) St. Peter 90-200 Municipal/Private < 10 ug!l off-
drinking water wells site
(3) Prairie du Ch1en-
Jordan 250-500 Municipal drinking 10 ug!l off-
water wells site
(4) Ironton-Galesville 700~750 Industrial usage < 10 ug/1 is
est i mat ed to
be on-site
(5) Mt. Simon-Hinckley 800-1100 Municipal drinking Not detected
water wells
Ground water contamination in each aquifer under the site is approximately
ten times higher than the off-site concentration shown above.
The Prairie du Chien-Jordan aquifer is the primary source of drinking
water for 110,000 people in St. Louis P~rk, Edina, Hopkins and all
comnunities adjacent to Hfnneapol15. The City of t1inneapol15 depends
exclusively on the Mississippi River as its drinking water source
and has considered utilizing the Prairie du Ch;en-Jordan as its secondary
source of water supply in the future. The deeper Mt. Simon-Hinckley
aquifer is the second most extensively used drinking water aquifer for
the area and it is utilized to such an extent that the Minnesota
Department of Natural Resources is concerned about further significant
appropriation of water from this aquifer. The St. Peter aquifer, while
it once was a ~ajor source of water supply, is now a minor source of
municipal drinking water supply because of the better water quality of
the Prairie du Chien.
t
The uppenmost aquifers, the Drift and Platteville, have in the past pro-
vided potable water to numerous private wells, but with municipal supplies
bec~ing available, they are no longer used for potable purposes to any
significant extent. However, there are still many private wells in the
shallow aquifers ~ich can be used for irrigation of lawns and gardens.
The extent of contamination in each aquifer varies greatly. No contamination
has as yet been found in the "t. Simon-Hinckley. The hydrogeology of the
site suggests that the St. Peter aquifer is contaminated. Further sampling
of wells near the site is expected to confinn this assumption. The area
of contamination in t~e Prairie du Ch1en-Jordan extends east beyond Highway
169/100 and has the greatest potential public health impact due to the.
number of municipal water supply wells located just outside the presently
known contaminated zone. The spread of contamination usurps the aquifer's
-------
,"... - _.' ...~.- ...'. ....~- '..' ""'.""'..,;,.',r.,-....,.....-.., ,,'.'.. .' ..-~., "-'.'-.
".", - --,..',:";.'
. '. .'~; -'- '~... '.,,: 0:.
,-". .":~ ".,. -.' r.~ ,L',.;, ".~.t;..~..,::''':..,..i':f.''...,~'::;.~'''.\;''' .......t~.t. -..., .....
-9-
Contamination of the Prairie du Chien-Jordan aquifer occurred by two modes.
One is through direct contact of the aquifer with the coal tar material
found in W-23. The material in this well has, for the most part, been
removed. Another mode of contamination is through the inadequately con-
structed multiaquifer wells that allow contaminated water from the upper
aquifers to be transported along the outer diameter of the casing into
the deeper cleaner aquifers. These two mechanisms are the primary
pathways of contamination of the Prairie du Chien-Jordan aquifer which
resulted in the closure of six St. Louis Park wells and one City of Hopkins
Well.
Releases of PAH and related coal-tar distillate material to the environment
are still occuring. The primary methods of contamination of the uppermost
aquifer (Drift/Platteville aquifer) is through the contaminated soil at
the site and the bog south of the site which act as sources for migration
into the ground water. Contamination of the uppermost aquifer has been
found to a depth of 90 feet in the bog area. It seems that the contamination
is not evenly distributed throughout the bog, rather, the area and depth of
soil contamination appears to be representative of channel into the bog
area. This is probably a consequence of the ditches used by Reilly to dis-
pose of wastes. As the contamination dissolves into the aquifer it moves
east, southeasterly where it migrates through a bedrock valley into the
Platteville aquifer and toward the St. Peter aquifer.
Status of Remedial Action
t
Since 1981, the MPCA has been performing various actions at the site
funded through a Cooperative Agreement with the U.S. EPA. This, among
other things, led to a Record of Decision for construction of a GAC plant
at SLP15/10 (Appendix A) for restoration of drinking water for the City of
St. Louis Park. Well W23 was a major source of, and conduit for, contami-
nation of the Prairie du Chien/Jordan aquifer, the Ironton/Galesville
aquifer and potentially the Mt. Simon/Hinckley aquifer. In 1982-83 two
multiaquifer wells, W23 and WIOS, were cleaned and reconstructed to the
Prairie du Chien/Jordan and Ironton/Galesville aquifers, respectively, thus
serving as monitoring and potential purge wells in the area. About 100 feet
of coal tar material was removed from W23. No solid coal tar material was
found in Well WlOS, although the water in that well down to the Ironton/
Galeville aquifer was contaminated by dissolved coal tar material. The
task to clean out and properly reconstruct W23, although intended as an
initial investigation of the well, actually was a significant cleanup and
preventive ..asure that removed a substantial source of contamination to
the major drinking water aquifer in the area (Prairie du Chien/Jordan)
and eliminated potential multi-aquifer transfer of contaminated water
still in the Drift/Platteville aquifers to the Prairie du Chien/Jordan
aqui fer.
,
Other tasks perfonned through funding by the U.S. EPA/MPCA Cooperative
Agreement resulted in the Record of Decision (ROD) attached in Appendix A
and investigation of numerous private wells that could serve as conduits
of contamination to deeper aquifers as did W23.Reilly Tar and Chemical
-------
-10-
operating under test procedures and it is scheduled for full scale start-up
in June 1986. The GAC system can he used for a peak flow of 1100 gallons
per ninute (gpm) with an average use of approximately 500-600 gpm. This
significant effort is the first of a major remediation program of the aquifers
in the area of St. Louis Park.
Alternatives Analyses
The following analyses are presented in a format starting with the deepest
aquifer known to be potentially affected by the activities at the site,
the Mt. Simon/Hinckley aquifer, and concluding with analysis of the remedy
for surface and subsurface soil conta~ination at the site (Figure 3).
Of particular complexity are the analyses of the Mt. Simon/Hinckley
aquifer, the Prairie du Chien/Jordan aquifer, and the subsurface soil
contamination. Thus, most of the discussion relates to these three
formations.
It should be noted herein that the Remedial Action Plan (RAP) for the
site to be implemented by Reilly Tar and Chemical Corporation is 96 pages.
The RAP. is very specific with respect to action. levels and cessation
criteria for each remedial action requiring the pumping of an aquifer.
It is not reproduced in this EDD and is noted here by reference as the
RAP. A~so, extensive water and soil quality analyses have been conducted
throughout the Remedial Investigations. Two families of compounds, PAH and
phenolics, are consistently found, directly relate to the coal tar distil-
lation processes, and are the compounds of healt~ concern found in the
water supplies. Other organic and inorganic compounds have been monitored
and found in substantially lower quantities, ord@r(s) of magnitude less
than the PAH and phenolic compounds identified in the Remedial Action Plan
for implementation at the site. This is not unexpected due to the known
process used by Reilly in its distillation and wood treating. The target
list of co~pounds for monitoring is given in the RAP, pages 92-94.
t
Aquifer Characteristics Analysis -
Hount Simon/Hinckley Aquifer
The Mt. Simon/Hinckley Aquifer is the deepest aquifer in the geologic
sequence beneath the Reilly site that may have been contaminated.
During the Remedial Investigation no contamination was Measured in the
Mt. Simon/Hinckley. The physical characteristics of the aquifer are -
,
Geologic characteristics:
Sandstone, grayish white to pink, silty to
course grained, well cemented, quartzose;
parts are medium to course grained, well
sorted.
Approximate range of thickness:
Up to 260 to 270 feet; starts at approximately
-------
'..' ~\. . - ",." . , . .;, '.. '.': --' ",.J . "11"'-,. .;.~ '. ... '..' ~:.., . ... ,-', . -::.-. ...':,.!. ...' ..:_I,.~-.....:.. ",-,,';'" ~-; ; ..:' .'t! ..,.\.l .' .: ._,,- To -::-..\...'......: ~ '~""-'_-:;.' z': ~-:. ~'- .~.'~-,",,~.:. '0' 0'...". ... . I. r .
';:..',-::- ..:~~.~.::-, h-. .---' :....,:,-- .'~'--'''~'''... ._t....' -~'-.t..'...~'.:...
-11-
Areal extent:
Underlies the entire study area (Figure 1).
Water bearing characteristics:
Porosity is intergranular; high transmissivity.
Generally discharges more than 1000 gallons
per minute to high capacity wells.
Supplies. about lS~ of ground water pumped to
St. Louis Park and the seven-county
metropolitan area.
Use:
Wells of interest Year Constructed Depth (feet) Original Construction
W 105 1899 940 multi aqui fer
~, 23 1917 909 multi aquifer
W 38 1913 1002 multi aquifer
SLP 11 1961 1093 single aquifer
SLP 12 1963 1095 single aquifer
SLP 13 1964 1040 single aquifer
SLP 17 1983 1082 si ngl e aqui fer r
Multi-aquifer wells WI 05 , W23 and W38 were of similar construction and
could have allowed downward migration of contaminants from overlying
aquifers to the Mt. Simon/Hinckley. Wells WI05 and W38 have been recon-
structed and grouted to the depth of the Ironton/Galesvi1le aquifer by
the MPCA and are used for monitoring wells.
Well 23 was investigated to a depth of 860 feet, the top of the Mt. SimonI
Hinckley aquifer, before it was resealed. During this investigation, at a
depth of 600 to 740 feet, a plug of coal tar derivative was removed and caused
some contamination of the water entering the bore hole into the Mt. Simon/
Hinckley aquifer. One sample taken at the depth of 860 feet showed contami-
nation of 1 part per million of PAH compounds which was probably due to the
material that was removed from the bore hole 120 to 180 feet above the
Mt. Simon/Hinckley aquifer. W23 is probably the only source of contamination
to the Mt. Simon/Hinckley Aquifer. None of the municipal wells finished
into the Mt. Simon/Hinckley aquifer, SLP: 11, 12, 13 and 17, displayed
evidence 0' contamination.
Representative ,..ples 0' the Mt. Simon/Hinckley aquifer could not be
collected during clean out of wells W10S and W23. Many scenarios exist
as to the mechanism and duration of contamination, if any, entering the
Mt. Simon/Hinckley aquifer and are separated into best case and worse
case hypothetical situations. If contamination did enter the Mt. SimonI
Hinckley aquifer, it would have entered via down through the multi-aquifer
wells W23, W10S, and W38. All of the wells were found to be backfilled,
due to their open-hole construction, above the Mt. Simon/Hinckley aquifer.
This process probably occurred over several years follow1ng construction
of the wells, and thus probably greatly impeded downward flow 0' contami-
-------
." .......-- '.".7'....-.-....& ""'-. '.~. -~_....__.... ""'-""-'---'.'_.."~' _.~.-_._._,-_....... "'''''-'''''~'-"''_.__...-._-,_..._-_...-.-....._-..~ _._-_.~.._-- -- .
-12-
data gathered during the clean out of W10S by the MPCA in 1984, this well
does not appear to have significant coal tar material beneath the Ironton/
Galesville aquifer. W38 own by the Milwaukee Railroad Company, briefly a
multi-aquifer well during its construction was capable of allowing contam-
inants from the upper aquifers to disburs~ into the Mt. Simon/Hinckley
aquifer. However, it did not regularly have any coal tar material seeping
into it as W23. The well was drilled to the Mt. Simon/Hinckley in 1913
and casing placed down to the St. Peter aquifer. The open borehole.
between the St. Peter and Ht."Simon/Hinck"ley aquifers filled with native
aquifer material, and thus is not considered a conduit of contamination
to the Mt. Simon/Hinckley aquifer. Therefore, the most probable source
of contamination to the Mt. Simon/Hinckley aquifer is W23. With much
less probability W10S, 200 feet away from W23, could have briefly acted
as a dilute point source of contamination by multi-aquifer transfer. For
remedial purposes these two wells, due to their proximity, can be consi-
dered a point source of contamination to the Mt. Simon/Hinckley aquifer.
Screening of Alternatives and Alternatives Analysis for the Mt. SimonI
Hinckley Aquifer
To investigate the Mt. Simon/Hinckley aquifer to test the hypotheses
stated earlier, an expensive remedial investigation, nearly equivalent to
the cost of remedial action, would be necessary if only to document that
the Mt. .Simon/Hinckley aqui fer is either not contaminated, contaminated
below an action level, or conta~inated above an action level. Since the
aquifer is more than 900 feet deep no other action than pumping can be
considered, since the only possible contaminant source to the aquifer,
the coal tar plug in W23, was removed by the MPCA in 1982. At that time
the well was properly sealed to eliminate the possibility of communication
of the Mt. Simon/Hinckley aquifer with the contaminated upper aquifers.
The following tables (Tables:2-7) provide the costs to investigate the
Mt. SimQQ/Hinckley aquifer for: 1) the least contaminated scenario, which
assumes that contamination flowed down-hole into the aquifer while W23
was being cleaned and reconstructed in 1982, and 2) the worst case scenario,
where W23, W10S and W38 are assumed to have allowed downward flow over a
number of years with the injection rates of contaminated water into the
aquifer decreasing with time as the well bores filled with natural aquifer
materials. There is alSO a third case, where no contamination of the
Mt. Simon/Hinckley has occurred; the cost to t.nvesttgate and confirm
this scenario would be equivalent to the worst clse scenario, since in
both cases the 90al is establishing the confines of a plume, which is
dependant upon the analytical capability of chemical instrumentation.
t
Present worth costs wire evaluated using both 5 and 10 percent interest
rates. The 10 p'ercent, 30 year rate is currently used in RI/FS work.
The 5 percent rate more closely represents a long-term historical average
and may be more appropriate considering the long-term monitoring and
contingent actions anticipated. Present worth cost beyond 100 years for
each interest rate are essentially the same as the present worth cost at
-------
.: ,,~' ;, :.".\ . .; "... ":,, .:..
~ ,.;' '. '., '
-'l. .\"'" ", . '- , , ,'.,
" ~:~'" ~. ':
..3" .:- . : ,,~, .. ~ '- ',:;: :',-".I.:~.:",",.." t'.(/>i ...:;1";':"- "~-;;~,,,"::..-,~...:;~,~:.:..,:,...":":;'" :-~.....r~,:" .~-"":;.:. . . :. .,.;.-:.:.": - ""\4--';:)"1: ~y',\.' .~: ,~... ,,_:fl.~""-':""" ,........~,_.....:~. ,. - .
-13-
It can be deduced from Table 5 that the cost for further re~edial investi-
gation, i.e., drilling new wells, dominates the costs of remedial action.
The comparison of remediation costs based on the findings of contamination
above drinking water levels varies between $270,000 and Sl,400,000, sub-
stantially exceeding the estimated cost range of $33,000 to S79,OOO needed
to continue present aquifer usage wit~ monitoring and contingent treatment
at the drinking water wells, SLPll and SLP17.
The costs for contingent treatment at SLP 11 and SLP 17 (Tables 3 and 4) are
based on known flow patterns. which have peen long established and documented
through historical pumping records kept by the City.
Therefore, the Remedial Action Plan (attached to the Consent Decree,
Appendix C) specifies that treatment systems will be placed in wells used
for drinking water purposes as a contingency measure. This measure will
be applied for 30 years after the effective date of the Consent Decree, at
which time new information pertaining to the aquifer will be reassessed;
. if necessary, contingencies for treatment of drinking water wells finished
in the Mt. Simon/Hinckley aquifer and any new municipal potable water wells
installed in that aquifer within a one mile radius of well W23 will be
monitored and subject to the above contingency. The drinking water
criteria are established in Appendix A and further explained in Appendix 8.
Contingent actions apply to a radius of one mile from W23, due to the
measurable contamination found approximately within a one mile radius of t
W23 in the Prairie du Chien/Jordan aquifer. Similarly, contamination has i
been measured in the surficial (Drift) aquifer up to approximately one
mile east of the site from where the leachate plume is generated.
-------
.... - .. " ... - -.." r..- ......., '- ,"., '.'",,~. ,.-..~ "'.--.', .....,~. "'.....:.. .~... "">~" . ~'. A- . ,~...~. .-. ""I..,"""~..",'.' . -"''-'"''''-',~. .". ".,." ~.-.~. '. .-, F .. ..' '".'''.,,, . ..,... '~...' . - .
-14-
TABLE 2
Present Worth Cost Estimate Summary for Remedial Approaches to
Mount Simon - Hinckley Aquifer Contamination *
--~-------Present Worth Cost (XSIOOO)
-------------
Re~edial Approach
Interest Rate
Best Case Contamination
5~
Worst Case Contamination
lOa:.
5~
10~
Monitoring
. and Contingent
Treatment
33-39
18-21
79
Remedial
Investigation
201
201
1002
Remedial Action
65-142
394
21-98
Remedi a 1
Investigation
and Remedi al
Action
240-317
1396
266-343
* Assumes 100 year time frame
,
19
1002
t
231
-------
, ,~, .. ",' . . J. ..., ""4 w. ...."~ '~..' ..'. ,",-';., }t," .';"",~.~'1........ ~'f. r. .1.:; .."".: ",;'..:'....,. ,;"',;';:"10 .. .o-:;'..'Ioo.l.""""',.:,J. ...... "n-. .', ~. :...~..,' .:' .. .
_....L.:''\'h' . "";''''"..i.. 'fC ;..R;;"'-":..~~,.""'" ;u'~'....~ :;..:I,'.o;,;..:t.: le.....{ ..a.'h-'..\.r..'~';'-....'.I::o-:.I.....1.t'''~''~,"-~;~>' ....1,;...,~"..,,: ~
-15-
TABLE 3
Estimated Costs for Monitoring ann Contingent Treatment
Best Case Contamination
Element
Years
Needed
Present or Present
Unit Cost (XS1000) Worth, 5' (XS1000)
Annual monitoring
of SLPll, SLP12,
SLP13, SLP17
0-100
1.6/yr*
33
Present
Worth, 10\ (X$1000)
18
Possibly Treat 100a+ 200** 0-1.5 0.0
SLP11
t
'Possibly Treat. 100a+ 600** 0-4.5 o.b
SLP17
Total
33-39
@ Based on hydraulic model utilized to predict transport of contaminants.
* Assu~es unit cost of $400 per sample for collection, analysis and
repo rt i ng .
**New treatment plant capital cost of $600,000 is assumed.
Capital cost for treatment of SLP11 estimated at $200,000 due to
existing facility at this location for SLPIO & 15 i~ Prairie du
Chien-Jordan aquifer.
"
-------
-, - ',:';;"
" '. ,.~- '". T. '.'--..:. .' " ... . .;" .. : -. ,.- .
'. . - .~. - ':.:':" ~ . -~'..':;"J.' .... '<~or'OJ.--,-' '~"I."'''.';-'-', "-""."-h,, .~...., -".., '-'''''''~ '.~...-.... --..., """,,'.. ~.~'4 .~..~ ~-""."""-'.~."'-'_." ..~. _.. -- .-- . -, .--..'-. -
-16-
TABLE 4
Estimated Costs for Monitoring and Contingent Treatment
Worst Case Contamination
Years Present or Present Present
Element Needed Unit Cost (XSI000) Worth, S' (XSl000t Worth, 10~ (XSIOOO)
Annual Monitoring 0-100 1.2/yr 2S 13
of SLP12, SLP13,
SLP17
Annual Monitoring 0-60 0.4/yr 8 4
of SLPll
Treat SLPll t
60-100@ i
- Treatment Plant 200. 11 0.7
- Quarterl y
Monitoring of
SLPl1 60-100 1.6/yr 1.6 0.1
- SLPl1 Treatment
Operation and
Maintenance 60-100 30/yr* 29 1.1
Treat SLP17 100+@ 600 4.5 0.0
Total
79
19
@ Based on hydraulic model utilized to predict transport of contaminants.
* Operation and maintenance consists mostly of carbon replacement
and electricity costs. Low-end of carbon replacement cost was
S18,OOO/yr and electricity estimate was SlO,OOO/yr in CH2H-Hill
-------
. ~."""
'.. "~..._.. ~ ,'" ... .,.., '-..
.I. .' ..' ..,. -' , ...... .' .' .'.', '.,'. '. ~~ -.. ,'. ~ . ..." .. . ,. ..~ .
~.' .:. - ~..> ,.t;.,- .1..J"':<,~.,." ";""":'''~'-',:.,'''.'.~. ...T.\.,-:-.,~l~.,,:'... -.:..~~,~.. 1.:-...,\,,-'!::-.-..-:-....--\ ,-;
-17-
TABLE 5
Estimated Costs for Remedial Investigation
Best Case Contamination Worst Case Contamination
u Element Cost (XSlOOOt Element Cost ( X$1000t
One We 11 200* Two wel1 s North 1000*
North of W23 of W38. Three
Wells North of
W23
Two 0.8 Two Monitoring 2
Monitoring Events per Well
Events
t
Tot a 1 201 Total 1002
* Assumes well construction. development. permanent sampling pump
installation and mobilization costs totalling $200.000 per well.
-------
-18-
TABLE 6
Estimated Costs for Limiting Contaminant Spread *
Best Case Scenario
Years Present or Unit Present Present
Element Needed Cost (XSlOOO). Worth, 5' (XS1000) Worth, 10' (XS100Q)
Possible Gradient
Control At W23 Area
(SOgpm)
- Monitoring Well
Conversion 0 0-15a 0-.15 0-15
- Electricity for 2/yrb
Pumping 0-2.5 0-5 0-5
- Quarterly
Effluent t
Monitoring 0-2.5 1.6/yr 0-4 0-.
I
- Sanitary Sewer 0-2.5 21/yrC 0-53 0-53
- Post-pumping
Annual Monitoring 3-100 0.4/yr 32 3
Annual Monitoring of
SLP11, SLP12, SLP13,
SLP17 0-100 1.6/yr 33 18
Total for Remedial Action
65-142
21-98
*Does not include capita1 cost for well construction used in RI (Table 5).
alncludes pump installation/modification. controls and sewer and
power connection.
bAssumes electricity charge of SO.OS/kilowatt-hour and 70 percent
efficiency. '
-------
'. .., .. ~,......... ,,~ . .', "... ....,. '.."'.. . .... '-~"",":' .., '....1.......' ~ ":..t~_.....s '.\ .;..... "'- .- ".-,. ...:-- ,''''.,1., -'.1..:.#,..:' ,. ,~ . ..,b". -" ~. ,'I" -# ~ ~
". - . ,~.~.!.. _....~ .1:\- .. ~. , "1.""" .--",'......... -......... _4 . "
.'.'". '-. '.'":.
. ...' "-.---, _. -~ ,-, "
~.,..., - -.- ,.,'" ,
-19-
TABLE 7
Estimated Costs for Limiting Contaminant Spread *
Worst Case Scenario
Years Present or Unit Present Present
Element Needed Cost (XSlOOO) Worth, 5' (XS1000) Worth, 10' (X$1000)
Gradi ent Control
Pumping Second Well
North of W23 at
u 250gpm
- Monitoring Well
Conversion 0 15a 15 15
- Elect ri city for 10.3/yrb
Pumping 0-65 208 113
- Quarterly Effluent
Monitoring 0-65 1.6/yr 32 18
- Post-pumping Annual t
Monitoring 65-100 O. 4/yr 0.3 0.0;
i
Gradient Control
Pumping Well Nearest W38
at SOgprn
- Monitoring
Well Conversion 0 15a 15 15
- Electricity for 2/yrb
Pumping 0-40 36 22
- Quarterly Effluent
Monitoring 0-40 1.6/yr 29 17
- Post-pumping Annual
Monitoring 40-100 0.4/yr 1.1 0.1
Annual Monitoring
of Four SLP and
Three Monitoring
Wells 0-100 2.8/yr 58 31
,
Tot a 1 394 231.
*Does not include capital cost of new well construction used for RI (Table 5).
aIncludes pump installation/modification, controls and sewer and power
connect ion. .
bAssumes electricity charge of SO.OS/kilowatt-hour and 70 percent
-------
. .."." -..'.. ..~. .. .-... .'...' -'., ...~~ ,.~ .'-~.-'''-,'''.- _.-"-. .-. - ..~...~....._-..~,.. _._._..,~- -~.., .,. _"-'''--''-.'_-'_~n-- ... .-- '-'_'_'_-h____.--- ._,--- ~_..._---
-20-
Aquifer Characteristics Analysis -
Eau Claire Confining Bed
Geologic characteristics
Approximate range of thickness:
Siltstone and shale, green glauconitic.
Up to 105 feet.
Areal extent
Underlies entire study area.
Confining bed; hydraulic characteristics
poorly known.
Water bearing characteristics
Use:
Aquitard. No remedial action necessary.
Ironton/Galesville Aquifer
Geologic characteristics
Sandstone, white to light green,
moderately well sorted, fine to course
grained, quartzose. t
Approximate range of thickness:
Up to 50 feet.
Areal exte!1t
Underlies entire study area.
Water ~earing characteristics
Use
Porosity is intergranular; low
transmissivity.
Regionally an aquifer, but no wells
are known to yield water exclusively
from this unit in the study area.
Screening of Alternatives and Alternatives Analysis for the Ironton/Galesville
Aqui fer
Because of the aquifer's depth, and limited sources of contamination by W23
and at one time possibly WlOS, pumping the aquifer and contingent actions
were evaluated. The only known source, W23, already has been corrected as
previously discussed. Because of the li~ited yield and naturally high
inorganic levels found in this aquifer it serves limited use due to the
abundance 01 better water yielding aquifers above and below the Ironton/
Galesville.
Due to the aquifer hydraulic and physical characteristics, contamination
introduced through Wells W23 and WIOS should.still be in the vicinity of
t~ose two wells. Little hydraulic or pumping stresses are exhibited in
this aquifer. The aquifer is not used for municipal supplies due to its
depth, inorganic water chemistry and yield. Conceptually, remedial action
in this aquifer should be applied at the source where contamination may
exist (W23 and/or WIOS) and, thereby withdraw a relatively high percentage
of contaminants in a relativ~ly short time period. This would reduce the
effect, if any, of contaminant migration through the Eau Claire confining
-------
\-... ..,~ ...,:".'I.~ - ---,'-,' . '., ',~. . ;.'..'. ;,..;.-."
. ",";"". ,..;. .".
',.'; '..." , ..' ., .: .;': ... -, r:':.;\ .-. .""" .'~'. ::',:'.'""..' ...... ':L.,J..,.~'~~.,.~"...;..;.....:-.::Ir'.....~, :~"::;'.."..l"f:"'j,....."~~,,,"'\i.~.;.:: .~. ::L'..C; ti.~~... .:. ~':.' <. .l.l.-~ ~.:'.,d;-,.~,~ ;_1:~..t.;t~:..;.~ 'l~".. ,.:" .': .
-21-
u
has been reconstructed into the Ironton/Galesville aquifer, will be pumped
for two years or until the cessation criterion of 10 micrograms per liter
of total PAH is reached, whichever is a longer time frame. Discharge of
the extracted groundwater to the MWCC sanitary sewer will be proposed by
Reilly. As a c~ntingency, in t~e unlikely event that a municipal drinking
water well is established in this aquifer within one mile of W23, that
well will be monitored and if.its water q~ality exceeds the drinking
water criteria established in Appendix A and R, treatment facilities will
be installed. -
Aquifer Characteristics Analysis -
St. Lawrence - Franconia Confining Bed
Geologic characteristics
Siltstone and sandstone, gray to green
poorly sorted, glauconitic and nolomitic.
150-250 feet.
Approximate range of thickness:
Areal extent
Underlies the entire study area.
t
Water bearing characteristics
Confining bed; hydraulic characteristi~s
poorly known.
Ilse :
Aquitard.
No remedial action necp.ssary.
Prairie du Chien/Jordan Aquifer
Geologic characteristics
- Prairie du Chip.n Group - Dolomite, sandstone, sandy dolomite,
light brown, buff. gray, thinly to
thickly bedded.
- Jordan Sandstone
Sandstone, white to pink, fine to
coarse-grained, moderately well
cemented, quartzose to dolomitic.
Approximate range of thickness:
- Prairie du Chien Group - 0-170 feet
- Jordan Sandstone - 0-130 feet
'J
Areal Extent:
- Prairie du Chien Group - Absent in north and west parts of
study area. Locally absent due to
eros i on.
- Jordan Sandstone - Absent in extreme west and northern
-------
Water bearing characteristics
- Prairie du Chien Group
- Jordan Sandstone
Use:
,
-22-
- Generally yields more than 1,000
gpm to high capacity wells.
Hydraulic conductivity is due to
fractures, open joints, and solution
channels.
~
- Hydraulic conductivity is mostly
intergranular but may be due to joint
parting in cemented areas. Prairie
du Chien/Jordan aquifer generally
yields more than 1,000 gpm to high
capacity wells.
The Prairie du Chien/Jordan aquifer
not only supplies about 80 percent
of the groundwater pumped in the
study area, but a1.so provides
approximately 75 percent of the
annual ground-water supply in the
Twin C1t~es. .
-------
. .', ,""'. .... .", .,\.~. . _...!...~...;-........ r.:, '-' -',~.... ~..:...,;.," o,Y&.. "'-".co 'ri!).W.. .~!',~,"'-t;"\'~'\'.\,f\._~.....'t,-'::J."'''''~'...';'~.;:~")--1o.}._......i':;1,..;;'(j'."..",...':Lo-,,,,,,""'~!"":. ...' "-",-. o~.' w_.~",,,,. ~ °0"", \.111,0 '"" -.. ....~ .t.... . ..,h. -. ...~.' ". ...' ... ..': '.'" , '0
-23-
u
Screening of Alternatives and Alternatives Analyses For the Prairie du
Chien/Jordan Aquifer
As discussed in the ROD (Appendix A) t~e Prairie du Chien/Jordan aquifer
is a high priority resource in the study area and throughout the State of
Minnesota. The population of St. Louis Park and the neighboring communi-
ties of Edina and Hopkins, depend ~eavi1y on the Prairie ~u Chien/Jordan
aquifer for their water supply. It also serves as a potential secondary
source of water supply for the Twin Cities.
Well W23 has been cleaned within the borehole and properly reconstructed
to the Prairie du Chien/Jordan aquifer. As such, it becomes a source
control well which can be utilized to remove the contamination in the
aquifer remaining near the borehole. Near W23 there are relatively high
concentrations of PAH and to a lesser extent phenolics, which rapidly
decrease as pumping goes on for 24 hours. Thus, W23 provides the
opportunity to control the remaining source of contamination in the
aquifer. As part of the aquifer's management, this well will be pumped
until cessation criteria are reached. The discharge will go to a sanitary
sewer under permit by the Metropolitan Waste Control C~ission (HWCC). t
The well wi 11 be pumped at 50 gpm for a minimum of 5 years or unt 11 10 .
micrograms per liter of total PAH is measured, in accordance with the
ce~saiion criteria presented in the RAP.
In addition to the source control at W23, a hydraulic control of the
aquifer will be imple~ented for the purpose of restoring drinking water
quality to St. touis Park Wells and to protect the use of uncontaminated
water by St. Louis Park, Hopkins, and Edina. Models produced by Reilly
and the USGS/~PCA indicate that the existing drinking water we", SLP4,
which has been closed due to the presence of PAH compounds, should be
restarted and pumped at approximately 1,000 gpm. A NPDES discharge per-
~it will he necessary and a study to determine the feasibility and the
location of the discharge will be conducted by Reilly Tar and Chemical
Corporation.
.J
A gradient control well system will be implemented in the Prairie du Chien/
Jordan aquifer. The actual placement or utilization of existing wells for
gradient control will be defined in the forthcoming FS specified in the RAP.
Water pumped from SLP4 can be used for drinking water if drinking water
criteria are consistently satisfied over a one year time period and a
monitoring plan for this well is submitted by the Reilly Tar and Chemical
Corporation and approved by the Department of Health Commissioners. A
total of 10 wells (including the possibility of constructing new wells in
locations dete~ined necessary by ground water modeling, providing existing
wells are not accessable) surrounding the contaminant plume will be monitored
in the Prairie du Chienl Jordan aquifer semi-annually for the first f~ve
years, and annually thereafter. Additionally, nine more wells are to be
monitored annually. Contingent actions also apply to these wells.
In the event that any more drinking water wells become contaminated, treat-
-------
. '.'. 1; '>f.' '. ~'.- .."..''- '.""',.'. ...'. "',..: ;-; .}: .. .;-......':"~"-,,-. .~ ...1'.-..... ~ .._~. """':'-."'. """'-~' '-.....:,.- "'...-;.:"':;'"...'. "'~--,':',,". -, ". ..", .. '-u',
~-_.,.~.,... -'" -"- .,,,,,,,...~,,,,-",,,,~.._.~...,~...._-.,~.._. ';-,--"... _U"''''~. .~~... _... .---.... --"__".M' ~-'--''''''--'''4. _"M~._.w".,~,,~-- ~ ....- - ...~ MM
-24-
In the event that any monitoring well exceeds drinking water criteria,
Reilly shall propose a plan for adjusting existing pumping rates, adding
new pumps to existing monitoring wells or any solution that is approvable
by the regulatory agencies that are party to the Consent Decree.
The objectives of protecting future current use and restoring future use
of the Prairie du Chien/Jordan aquifer can be accomplished with the
implementation of the above source/gradient control system and contingencies.
It is estimated that the ground water can. be purged sufficiently to become
clean within a 30 year time period. Nevertheless, the cessation criteria
for implementation of the above remedy are based on a statistical analysis
of the water quality at all of the monitoring wells such that the gradient
control system or its modifications must be operable if anyone of the 19
monitoring wells shows contamination above drinking water criteria.
Thus, the cessation criteria for imple~ntation of this remedy are
independent of time and the hazards of predicting a time period of
operation.
t
-------
, . . ~ ,,'. . <" .
. ~ ..' .,' ~'. r :~- t .,~ h"'.:..=.t ~..!' ~'":..'1......." '., ~ t ~":"'~'" - -' -. -. (,:'-...' .'.. ..'~~~. : "'...~....'.,,. ~ .1:.' ,., .'t,',., ';..-".' . '..., . . .;- -".' .:~ - ..... '- - ,~ .". - ....' ...""". " . - ", .", ,'.',.., - '. ..-...- ",...' .' '.';' --.. -'." ~ ~. ."", "".- .".,' ...., - h_- ,
-2 !>-
Aquifer Characteristics Analysis -
Basal St. Peter Confining bed
Geologic Characteristics
G
Approximate range of thicKnes~ :
Areal extent
Water beariny characteristics
Use:
Siltstone and claystone, red, green,
and white; parts are plastic in tex-
ture and poorly indurated; inter-
bedded with fine-grained quartz
sandstone.
0-65 feet.
Generally present over most of the
central part of the study area.
Locally absent due to erosion.
Hydraulic conductivity is highly
variable; siltstone and claystone
restrict vertical flow but sandstone
discharges as much as 100 gpm to
we 11 s .
As a whole, the Basal St. Peter con-
fining bed is an aquitard. No wells t
are known to yield water only from I
this unit in the study area. Thus, no
r~ediation 1s necessary.
St. Pete~ Aquifer
Geologic characteristics
Approximate ranye of thicKness
Areal extent
Water bearing characteristics
Use
,
'J
Sandstone, whit~ to yellow, very well
sorted, fine-to medium-grained,
poorly cemented, quartzose.
0-100 feet
Generally present over ~ust of the
study area. Locally absent due to
erosion.
Priority approximately 30\; can dis-
charge more than 500 ypm to wells,
Sandstone is poorly cemented and wells
tend to pump sand or clog.
Supplies about 10\ of ~roundwater pumped
in the St. "Louis Park area. Most we 115
in this sandstone are of small diameter
-------
-26-
Screening of Alternatives and Alternatives Analysis for the St. Peter Aquifer
Recently, it has been confirmed that the St. Peter aquifer is contaminated,
thus far, to a much smaller extent than the Prairie du Chien/Jordan aquifer.
Samples collected and analyzed in 1984 and 1985 showed trace levels of
PAH and phenolic compounds in two wells finished into the St. Peter aquifer.
These well W24 and W133 are located near the bedrock valley where it has been
theorized that water from the contaminated Drift and Platteville aquifers
have migrated to the St. Peter 'aquifer.
.,>
The Glenwood shale which has very low hydraulic conductivity is eroded in
the area of the bedrock valley and allows for downward migration of the
contaminated water in the upper aquifers. Multi-aquifer wells connecting the
contaminated Platteville aquifer with the St. Peter aquifer may also be a
pathway for contaminant transport to the St. Peter aquifer. Since there are
only 3 known St. Peter wells in the area of the bedrock valley, the precise
extent of contamination is unknown. Therefore, further remed1alinvestiga-
tion is required by the RAP whereby five new wells will be drilled into the
St. Peter aquifer. These five wells and eight existing wells in the St. Peter
aquifer will be monitored for PAH and phenolic compounds. If, after the remedial
investigation, the Regional Administrator (RA) determines that a feasibility
study ts needed, Reilly will proceed with an analysis of alternatives to t
limit the spread of contamination that exceeds drinking water 'criterfa. If
necessary., a gradient control system will be established, similar in con-
cept to that explained for the Prairie du Chien/Jordan aquifer and Reilly
will propose cessation criteria consistent with the purpose of limiting
the spread of contamination.
A multi-aquifer well investigation will also be performed by Reilly and a
report describing the impact of the contamination contributed by the wells
will be submitted to the RA. This investigation applies to any multi-aquifer
wells located outside an area in the St. Peter aquifer under remediation.
Thereafter, Reilly can propose or the RA require abandonment and/or re-
construction of those defective wells.
Aquifer Characteristics Analysis -
Glenwood tonf1n1ng Bed
Geo1og1c characteristics
"
Sha1e and c1aystone, green to buff,
plastic to slightly fissil, lower 3
to 5 feet grade from claystone with
disseminated sand grains to sand-
stone with clay matrix.
0-18 feet.
Approximate range of thickness
Areal extent
Present only in central part of study
-------
..,._.......~..."":'-.~_.-.....J..A,~...,....~......-..-....;-.. ."0.' :._",."";'.."'.~._."-,'...:..;-;,,,--':. ..--. ,.:- ...~'.- -l -r"'~"",,-, .f.~,.".-.. . -',._,.'::.""'''.'''.",-,. .'~-'" '_".'.n....~'-.<.._._'
-27-
Water bearing characteristics
Very low hydraulic conductivity
is estimated to be about 10-10
feet/second based on laboratory
measurements of core samples.
Use:
Aquitard. There are no wells in
this confining bed and no remedial
action is necessary.
G
Aquifer Characteristics Analysis -
Platteville Aquifer
Geologic characteristics
Dolomitic limestone and dolomite,
gray"to buff, then to medium bedded,
some shale partings. Solution
channels and fractures are concen-
trated in upper part and contain
sand and gravel of glacial origin.
0-35 feet.
Approximate range of thickness
Areal extent
t
Present only in central part of s~udy
area. Dissected by erosion. !
Water bearing characteristics
Use:
Hydraulic conductivity primarily from
fractures, open joints and solution
channels. Specific capacities of wells.
are generally between 10 and 100 gpm
per foot of drawdown, if pumped at
about 12 gallons/minute for 1 hour.
Results from one aquifer test indicate
that the transmissivity of the unit is
about 9000 ftZ/day near the test site.
The Platteville aquifer is a lower-
capacity commercialized industrial water
supply.
Screening of A1ternat1v8s and Alternatiye Analysis for the PlatteYille Aquifer
Due to its hydrau1ic relationship with the Drift aquifer, discussion of Alter-
natives Analyses 15 confined under the heading of the Drift aquifer.
,
Aquifer Characteristics Analysis -
Decorah Shale Confining Bed
~
Geologic characteristics
Shale, blueish-green to blueish-gray,
-------
-28- l)
Approximate range of thick.ness 0-95 feet.
Areal extent Locally present in the east of the
area of study.
Water bearing characteristics Confining bed.
Use Tne Decorah Shale confining bed is
an aquitard; there are no water
supply wells and no remediation
neces sa ry.
Glacial Drift Aquifer
Geologic characteristics
Undifferentiated over most of the
study area. Till, outwash and
valley-train sand and gravel,
lake deposits and alluvium;
vertical and horizontal distribu-
tion of units is complex. In the
immediate area of the plant site,
units include an unconfined Upper t
Drift aquifer, a Middle Drift and i
a Lower Drift complex. I
50 to 400 feet. Less in the area of
study.
Approxi~ate range of thickness
Areal extent
Underlies the entire study area.
Stratified, well sorted deposits of
sand and gravel yield moderate to
large supplies of water to wells
(240 to 2000 ga110ns/ minute).
Results from one aquifer test in-
dicate that the trans~issivity of
the Middle Drift aquifer near the
plant site is about 9000 ft2/day.
Water bearing characteristics
Use
The Glacial Drift aquifer was a
source of water supply, both do-
mestic and commercial in the study
area.
-------
~., ,.: ,". ~ '.' -, -' ... .;,;.",..... ..:'!... .'~'...~.... ..:... ~,,:,\-:-..,; .J,. ':-~ ....'.. "..,. ...,'J--s-.,'.",... ',....~ ''''''\..: ';...' '.:'..... .0:.... '.' ;..~'.:..,.J.. ,',' .;;-{J'.''''' :.....:... :... "-. ",';.' '... ,.'.':1 .. -
.-'-. .,:"'",_,~,,,,',,."-'~","~'..",.".:,~r,'.., ..'
-29-
iJ
Screening of Alternatives for the Drift and Platteville Aquifers
As discussed previously, discharges from the Reilly plant into the bog south
of the site introduced contaminants to the Drift aquifer. These discharges
also had a large hydraulic impact to that area which enhanced vertical flow
from the Drift through the basal Drift aquitard (which is relatively conduc-
tive) into the Platteville aquifer. Because of the relatively thin conduc-
tive shale between the Drift a.nd Plattevil.le aquifers and due to the rela-
tively high levels of contamination in these two aquifers, it appears that
both can be remedied with the same technology. Both source control and
gradient control concepts apply to these aquifers.
For source control, Reilly is committed to installing two pump-out wells,
one in the Drift and one in t~e Platteville within 500 feet east of well
WI3 located in the bog. These two new wells will pump for a minimum of 5
years and discharge into the sanitary sewer unless another treatment pro-
cess is appropriate and approved by the RA. These two wells should effec-
tively mitigate the high levels of contaminants migrating off-site. At
the end of 5 years Reilly may submit a plan for ceasing operation of the
wells. Cessation criteria are not developed for the Drift and Platteville
aquifers since it is unlikely drinking water criteria will ever be attained t
near the site. The purpose of source control is to limit further migration:
of rela~ively highly contaminated ground water that would otherwise contami-I
nate the St. Peter aquifer which has drinking water quality and use; and,
to protect areas of the Drift/Plattev1lle aquifers that are not yet conta-
minated by leachate from the Reilly site. The wells, therefore, may be
pumped indefinitely or until such time Reilly can demonstrate, and the RA
concurs, that no further off-site degradation that is harmful to the
environment will occur.
..
The concept and purpose of gradient control tn the Drift/Platteville
aquifers is similar to source control. Once source control is implemented
the residual contamination downgradient of the source control wells will
still be free to migrate. Therefore, Reilly is committed to install a gra-
dient control well east of the site, within 500 feet of the existing WI2
monitoring well. Discharge to the MWCC sanitary sewer will be proposed by
Reilly. The well will be finished into the Drift/Platteville aquifer
since at this location. .ast of the site the two aquifers are, to a large
measure. hydraulically connected.
Northern Area Remedial Investigation/Feasibility Study (RI/FS) for the
Drift/Platteville Aquifers
\)
In accordance with the Remedial Action Plan in the Consent Decree, Reilly
will install a total of 6 new monitoring wells in the Drift/Platteville
aquifer in locations north, northeast of the site or designated in the
RAP. In addition to PAH and phenolic compounds. pr~ority pollutants and
-------
'"
-30-
A FS will be conducted and submitted to the RA for review. As part of the
FSt Reilly will develop alternatives to limit the spread of contamination
in this area of the aquifer and propose cessation criteria applicable to
the aquifers for review and approval by the RA. In any caset a comprehen-
sive monitoring program along with a quality assurance project plan will
be implemented by Reilly. .
Based on the review of the data produced by the Northern area RI/FSt source
contro1t gradient control and monitoring we11st the RA may require further
actions for the purpose of limiting the spread of contamination in these
aqui fers.
Contingencies for Remedial Action 1n All Aquifers
During the course of remedial action and after review of multiple sampling
events. the RA may decide that further remedial actions specified in the
RAP shall be planned and/or implemented to protect the environment.
Contingent actions are also prescribed in the RAP for the GAC treatment
system (Appendix A) used for restoration of drinking water quality and
quantity at SLP 15/10.
t
Screening of Alternatives for the Unsaturated
and Saturated Soil Beneath the Site
Preliminary studies show that the amount and cost of removal and treatment
or disposal of the conta~inated subsurface to be very large. Initial estimates
of 400tOOO yds3 of contaminated subsurface may be substantially conservative
and must he considered a minimum value. Other estimates performed by the
regulatory agencies and the USGS show as much as 1 million yds3 of subsurface
may be contal~inated at least 10 times the background value. In either case
remediation of the contaminated subsurface would require an ambiguous and
costly program estimated ~in1ma11y at 100 million dollars. The value of
such action was considered over the years and due to the duration of the
disposal of the contaminants into the subsurface (at least 50 years), the
duration of migration of the contaminants off-s~te (probably more than 60
years), and the amount of excavation, backfilling and construction performed
by the City of St. Louts Park Housing and Redevelopment Authority (a party
to the Consent Decree), no substantial benefit to the off-site. environment
could be realized f~ a soil removal/treatment program. The reasons that
the benefits fram such action are dubious can be summarized by reviewing the
distribution of the ofJ-site contaminants. If all on-site contamination were
removed. the amount of contamination in the Drift and Platteville aquifers
.would still be immense. Remediation of the aquifers by removal would still
take greater than 30 years, more probably 100 years which is considered an
infinite time on a present worth scale of 101. This is the reasoning for
pumping the Drift and Plattevil1e aquifers for an indeterminant amount of
time or until the RA determines that cessation of remedial action in these
aquifers will cause no further hazard or degradation to the environment and
recepto rs. The haza rd rema i nj ng to potent 11 1 receptors. then, is direct
-------
. ,. . '..' - .."..........'.-"'" ",/I.,;' h. ..,,,..,,,,, ,... U\,,,~"~::..I.;,....'-'...'. _.1'..<'~'-""""'.-.~:=-h.".-",;.2.'.L.-'-''''''-~'''''I- --~, """'-"..;'_-_",0 --'~O' ~ . ~h -...~ .. ~.--..-. '''.,. . ... 4 .. "4'- '. ...' -.. .." '... .,... ......4-. -._. ,""~-'.- .-.' <>4- -...- - .-. - --....- -.. - . --. --~. "~ .. .
"
-31-
contact to excavated contaminated material. This hazard can be and is
mitigater i ~ I, . 11 i I'Istitutional controls to be implemented through the
Consent Decree. The City and Housing and Redevelopment Authority have a
vested interest in maintaining and providing a clean subsurface environment
that is beneficial to their future needs.
OJ
Alternatives Analyses for the Saturated
and Unsaturated Soil Beneath the Site
The area of the bog, south of the site has been analyzed for years. How-
ever, the area south of the bog, as delineated in the RAP, may have received
some contamination due to leachate or natural drainage towards Minnehaha
Creek. Thus, Reilly will perform between 15 and 25 soil borings in an area
agreed upon by the RA after Reilly submits a plan for soil investigations
in the area. Thereafter, a progression of submittals to the RA by owners
and the City will acknowledge the owners' compliance with the State of
Minnesota's Statutes regulating construction on such contaminated areas and
the owners' affidavits will be filed with Recorder of Deeds. This provision
applies to current and future land owners in the entire on site and off-t
site study area.' . 'j
Wetlands Filling
As prescribed by the U.S. Fish and Wildlife Service, (FWS) , Reilly will
cover with at least one foot of clean fill specific areas lncated in the
wetland area that exhibit surficial contamination. The RAP specified
procedures ann dates to follow. Reilly will provide sufficient advance
notice to the FWS of wetland filling-and the FWS, along with the other
agencies, and shall coorrlinate its requirements with FWS as wetland filling
proceeds. The FWS and U.S. EPA have the approval authority for compliance
with the requirements for wetland filling.
The U.S. Army Corps of Engineers, (COE), recieved an application from the
City of St. Louis Park for a Nationwide Filling permit. This type of permit
does not require FWS and/or U.S. EPA input into a determination of mitigation,
from loss of wetland areas. The COE, after consulting with FWS, considered
the wetland loss to be insignificant and, consequently, no mitigation was
requi red.
J
Highway Construction South of Site
If the City proceeds with its planned construction of Highway 7, the City will
provide for proper disposal of contaminated soil and/or the water from this
construction. If the intersection is not constructed by October 31, 1989,
Reilly will continue to fill, cover and grade that area planned for the
intersectioh, and will maintain that area to promote drainage to a collection
system and otherwise minimize leachate of contaminants in the area delineated
-------
. - ,,-,. .<".-"";.." .. ",.,...",,,,"""";',, .~.--'::'.~..rh',:.' -'.::\ ~-,......;O-.. ~ ';';~:";',' '",;~'~~',."-A~ """...~':'.;:;~.''-N..v..i"'...N\"~...:;;...........-:.:t...'..:.,'',,,,:,:;;,)-,,,',1..........;'~-':.:ol-';'n'~.z..~....'_"""","',i ",'':.'.,;''" "'.'''''' ". ,...;--.. _u'" .~"", -. ,....,.. 0...' h"..'. .""~ . ~...'."" ,.-.... '. ... . .. ,. .-' ~~. >-- .-..
o
"
-32-
Development of the Site
The City and the Housing and Redevelopment Authority are responsible for mitiga-
ting any hazards resulting from their development of the 80 acre site, which
is currently used as a park for the most part, with two blocks of housing (con-
dominiums). The RAP prescribes actions that require proper disposal of any
contaminated excavated material removed off-site and otherwise to reduce
releases to the environment due to actions taken by the City or the Housing
and Redevelopment Authority. Before any development occurs a plan must be
submitted to the RA for approval. This plan will specify procedures and
schedules for accomplishing the remedial actions for mitigating releases of
hazardous materials as prescribed in the RAP. All Federal and State laws
pertaining to the handling and disposal of hazardous materials encountered
during any site development apply and are acknowledged by the City and the
Housing and Redevelopment Authority. Similarly, all Federal and State
regulations pertinent to the handling and disposal of hazardous materials,
such as, site safety plans, workers' safety plans, and quality assurance
project plans for chemical monitoring apply to site development, are
prescribed in the RAP and are recognized by the City and the Housing and
Redevelopment Authority. The City and the Housing and Redevelopment
Authority will also submit a site maintenance plan that will meet the
objectives of reducing the release of hazardous materials resulting from
these actions or remo~ing Jr properly treating such hazardous materials
in c~p1iance with all applicable environmental laws as specified 1n the
RAP.
t
The above objectives and conditions stipulated in the RAP and Consent
Decree apply to all current and future land owners on the site.
Compliance with Environmental Laws
It should be noted here that negotiations with the Reilly Tar and Chemical
Corporation and the City of St. Louis Park have been periodially progressing
since the Fall of 1982. Since 1981 litigation, remedial ;nvestigat10~s,
feasibility studies and cleanout of two contaminated wells on the site
have been cOIpleted. All of the work during this time frame was in accordance
with u.s. EPA po11cfes and the National Contingency Plan promulgated in 1981.
The Consent Decree requf-res compliance with all environmental laws and is in
compliance with specific environmental laws summarized here.
1) Resource Conservation and Recovery Act (RCRA) - This applies
primarily to the handling and/or disposal of hazardous wastes at
the site. The RAP is written in accordance with the RCRA require-
ments.
2) Toxic Substances Control Act (TSCA) - There were no TSCA regulated
-------
. -_.- .-.. o--..~, _. ..' or,.' 0".' "--'. ...~. ;>O\T-..'" ....'........ ..~..... "." 0.- .. ,"" . -.'. ......._--..'. "'..R .,- t. -.."'" . '.. ., 'n -....J';,,;. "--"""..., .." < ''''. ,"""'".... ......" "" ........ ......- ,,,,,",,,,,,,"''''''''.....7>....-... ~,-- ........-...'.~ ~..... ."''''''''''''''''L._'''''.' "... - --..
"~
-33-
3) Clean Water Act (CWA) - This Act and the Regulations under it are
applicable to the proposed remedial activities with respect to the
discharge of extracted groundwater, or contaminated surface water
from site, to either the surface waters or the sanitary sewers.
The CWA and its regulations set forth permitting requirements for
point source discharges that implement minimum treatment technology
standards and protect the quality of the receiving water. Reilly
has co~itted to obtaining National Pollutant Discharge Elimination
System (NPDES) permits as required for discharges to surface waters.
The remedial action plan specifies effluent limitations for the
draft permits; however, the final permits may contain additional or
different limitations as necessary to meet NPDES requirements. Dis-
charges to the sanitary sewers will be subject to, and comply with,
pretreatment requirements determined by the Metropolitan Waste Control
Commission. The conditions in the Consent Decree and Remedial Action
Plan are intended to require full compliance with the CWA with regard
to NPDES permitting and pretreatment requirements. Region V will
maintain its formal approval role over all NPDES permitting and
pretreatment. .
.t
The Act is also applicable to the remediation of wetland areas. U.S. EPA,
normally, has the responsibility to review and evaluate work being per-
formed in the waters of the United States for cnmpliance with t~e 404(b)(1)
Guidelines.
4)
Safe Drinking Water Act (SOWA) - Since drinking water criteria for PAHs
were not developed through the SDWA rp.gulations, it was necessary to
developed those criteria for PAH compounds. This was accomplished
through consultations with expert witnesses, MDH, MPCA and U.S. EPA
Drinking Water Program representatives. The criteria are listed in the
RAP and attached to this FoDD.
Responsiveness Summary -
The public has been well tnfonned throughout the RI/FS work and continually
infonled throughout the recent past. The MPCA has been implementing a
U.S. EPA approved Community Relations Plan since lq83. Public Hearings
sponsored by Reilly and the MPCA/U.S. EPA were held in the Spring of 1983
(See Appendix A). Since then the City, U.S. EPA and MPCA have been partici-
pating in public meetings with citizens and media concerned over the Reilly
site; on April ll, 1986, a press conference was held in St. Louis Park,
Minnesota, followed on April 17, 1986 with a public meeting. 80th events
discussed the legal and technical aspects of the Consent Decree - RAP for
the site.
,\
Schedule and Estimated Costs of Remedial Actions
In accordance with the ROD, Reilly Tar has completed construction of the
-------
o ~
~
-34-
The GAC plant is currently undergoing testing and should go into full
scale operation by the peaK summer water demands in 1986.
Since the RAP is performance oriented and time periods of implementation
vary with each aquifer, it is very difficult to estimate costs. Therefore,
costs for the remediation of the aquifers via source and gradient control
systems will be defined in the appropriate remedial investigations and/or
feasibility studies.
t
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