United Slates
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R07-87/007
September 1987
Superfund
Record of Decision:
Minker Stout/Romaine Creek, MO
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TECHNICAL REPORT DATA
(Hem read Instructions on the reverie before completing)
1. REPORT NO.
EPA/ROD/R07-87/007
2.
3. RECIPIENT'S ACCESSION NO.
>. TITLE ANO SUBTITLE
SUPERFUND RECORD OF DECISION
Minker/Stout/Romaine Creek - Romaine Creek Portion, MO
Second Remedial Action
S..REPORT DATE
• September 28, 1987
«. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME ANO ADDRESS
10. PROGRAM ELEMENT NO.
1. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME ANO ADDRESS
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. TYPE OF REPORT ANO PERIOD COVERED
Final ROD Report
14. SPONSORING AGENCY CODE
800/00
15. SUPPLEMENTARY NOTES
The Romaine Creek portion of the Minker/Stout/Romaine Creek site is located in
Jefferson County, Missouri,, approximately 20 miles southwest of St., Louis. Romaine
Creek starts at the- Minker area, and flows 4.6 miles to its confluence with Saline
Creek. Romaine Creek is located in a rural residential area, and is not used for
municipal, industrial, or. domestic purposes.. In the late 1960s and early 1970s, a
southwest Missouri chemical plant producing-2,4,5-T and.hexachlorophene contracted a
waste oil reclaimer to remove process residues.. The residues, contaminated with
2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were mixed with waste oils and sprayed as a
dust suppressant on a nearby horse arena. In March of 1973, the owner of the horse
arena had the contaminated soils removed to various portions of the Minker/Stout/Romaine
Creek site. Approximately 120 yd-* of this soil was used as fill in a ravine on the
Minker property, and since 1973, much has eroded into Romaine Creek. In 1982,
contaminated soils above 1 ug/kg TCDD were excavated from the Minker portion of the
site. The primary contaminant of concern is dioxin.
The selected interim remedial measure for the Romaine Creek portion of this site
includes: excavation and temporary onsite storage of soils and sediments contaminated
with greater than 1 ug/kg TCDD; and backfilling of the excavated areas with clean
material suitable for the establishment of a natural stream bed. The estimated present
worth cost for this remedial action is $4,488,000 with annual O&M of $28,000.
7. -
KEY WORDS ANO DOCUMENT ANALYSIS
DESCRIPTORS
b.lOENTIPIERS/OPEN ENDED TERMS C. COSATI Field/Group
Record of Decision
Minker/Stout/Romaine -
Romaine Creek Portion, MO
Second Remedial Action
Contaminated Media: soil, sediment
Key contaminants: dioxin
8. DISTRIBUTION STATEMENT
19. SECURITY CLASS (This Report)
None
21. NO. OF PAGES
19
20. SECURITY CLASS fTlliS pagei
None
22. PRICE
EPA Form 2220-1 (R*v. 4-77) PMKVIOUS COITION i* O»*OLCTC
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Record of Decision
OperaDle Unit Remedial Alternative Selection
SITE: Romaine Creek Portion of Minker/Stout/Romaine Creek NHL Site
DOCUMENTS REVIEWED
I am basing my decision primarily on the following documents describing
the analysis of cost-effectiveness of operable unit remedial alternatives for
interim management of dioxin-contaminated materials at the Komaine Creek portion
of the Minker/Stout/Romaine Creek NPL site. Additional documents considered are
included in the Administrative Record for this action.
- Operable Unit Feasibility Study - Komaine Creek Portion of the
Minker/Stout/Romaine Creek Site.
- Summary of Remedial Alternative Selection - Romaine Creek Portion
of the Minker/Stout/Romaine Creek Site.
- Responsiveness Summary - Operable Unit Remedial Actions for the
Stout and Romaine Creek Portions of the Minker/Stout/Romaine Creek Site.
- Federal Position Statement on Dioxin in Missouri, Centers for Disease
Control, December 7, 1982.
- Public Health Advisory, for the Minker/Stout Sitas, Centers for Disease
Control, March 17, 1983.
- Addendum to'March 17 "Public Health Advisory for the Minker/Stout Sites," •
Centers for Disease Control, April 7, 1983.
- Health Implications of 2,3,7,8-tetrachlorodibenzodioxin (TCDD) Contamination
of Residential Soil, Kimbrough, R.D., et al., Journal of Toxicity and
Environmental Health, 14:47-93, 1984.
- Memorandum, Review of Analysis Data for 2,3,7,8-TCDD in Romaine Green
Sediment and Biota, Jefferson County, Missouri, Stephen Margolis,
Ph.D., to Edward J. Skowronski, Agency for Toxic Substances and Disease
Registry, March 1U, 1986.
DESCRIPTION OF SELECTED REMEDY
The selected operable unit remedial action alternative involves the
excavation of soil and sediment in Romaine Creek contaminated with 2,3,7,8-
tetrachlorodibenzo-p-dioxin (TCUD) at levels exceeding one part per billion
(1 ppb). Contaminated materials will be excavated until a residual TCDD
concentration of less than 1 ppb remains. Excavation will not continue beyond
a depth of four feet, or once solid bedrock is encountered. Excavated materials
will be containerized and placed in temporary onsite storage until a final
management alternative is implemented. Storage structures for the excavated
material will be constructed on the former Edwards property adjacent to
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Romaine Creek. These storage structures will be designed and constructed in
accordance with the substantive requirements for hazardous waste storage
fact 11 ties under the Resource Conservation and Recovery Act, as amended.
Following removal of contaminated material from Romaine Creek, excavated
areas will oe backfilled with clean material suitable for the establishment
of ci natural streambed.
DECLARATIONS
Consistent with the Comprehensive Environmental Response, Compensation,
and Liability Act of 1980 (CERCLA), as amended, and the National Contingency Plan
(40 CFR Part 300), I have determined that excavation and interim onsite
storage of TCDD-contaminated materials at the Romaine Creek portion of the
Minker/Stout/Romaine Creek site is cost-effective, consistent with a
perttanent remedy, and provides adequate protection of public health,
welfare, and the environment. The remedy selection procedure and selected
alternative comply with provisions of the Superfund Amendments and Reauthorization
Act of 1986. The State of Missouri has been consulted and concurs with
the selected remedy.
I have also determined that the action being taken is appropriate when
balanced against the availability of Trust Fund monies for use at other
sites. The selected operable unit remedial alternative is consistent with
Section 300.68(c) of the National Contingency Plan, and is a component of a
total remedial action which will attain all applicable or relevant and
appropriate requirements for. the protection of public health and environment.
Date p Regiorfal Administrator /
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SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
ROMAINE CREEK PORTION OF THE MINKER/STOUT/ROMAINE CREEK SITE
JEFFERSON COUNTY. MISSOURI
The purpose of this document is to state the interim remedy that the
Agency has selected to implement at Romaine Creek. This document will
also include a brief analysis of remedial action alternatives which
have been evaluated leading to the Agency's decision of remedy preference.
An operable unit is defined as a discrete part of an entire response
action for an uncontrolled hazardous waste site which functions to decrease
a release, threat of release, or pathway of exposure of site hazardous
substances. Operable units must be consistent with the final remedy for
a site and must be cost-effective according to the provisions of SARA.
It is assumed in this document that the final remedial action for the
Romaine Creek operable unit will involve offsite management, which will
require eventual excavation of contaminated soil and sediments.
SITE DESCRIPTION
The Romaine Creek portion of the Minker/Stout/Romaine Creek hazardous
waste site is located in Jefferson County, Missouri, approximately 20
miles southwest of St. Louis. Romaine Creek starts at the Minker area
and flows 4.6 miles to its confluence with Saline Creek. Saline Creek
empties into the Meramec River 0.2 miles downstream.
Romaine Creek is located in a rural residential area. There are no
businesses or industries located in the watershed, and the water is not
used for municipal or industrial purposes.
There are some private wells in the area, but most residential water is
indirectly supplied from St. Louis County Water Company. Due to its
small size, and intermittent flow in the upper reaches, the creek is not
used for domestic water supply.
The first mile of the creek has a moderate channel gradient and steep
slide slopes, and the remainder of the creek has a moderate to low gradient
and flatter side slopes. Approximately the upper half of the creek is
dry much of the year.
SITE HISTORY
The Minker/Stout/Romaine Creek site was placed on the Environmental
Protection Agency's (EPA) National Priorities List (NPL) of uncontrolled
hazardous waste sites in 1983 because 2,3,7,a tetrachlorodibenzo-p-dioxin
(TCDD) was detected in the soil. A historical investigation of the situ-
ation indicated the contaminants originated from a chemical plant in
southwest Missouri, which produced nexachlorophene and 2,4,5-T in the late
1960's and early 1970's. •
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In 1971, a Missouri waste oil reclaimer was contracted to remove process
residues contaminated with TCDO from a tank located at the southwest Missouri
plant. This material was subsequently mixed with waste oils and sprayed as a
dust: suppressant on the Bubbling Springs Horse Arena near Imperial, Missouri.
In March of 1973, the horse arena owner contracted with a local hauler
for the removal of the contaminated soil from the arena. The arena was
excavated and material was deposited at the various portions of the
Minxer/Stout/Romaine Creek site. Approximately 120 cubic yards of this
excavated soil were placed as fill in a ravine at the Minker property.
Since 1973, a significant quantity of the MinKer fill has eroded into
Romaine Creek.
Sampling for TCDO
The EPtt Initially sampled and analyzed Romaine Creek sediments for TCOD
in 1982. Approximately 150 samples were collected from the Minker area to
near the mouth of the creek. At a detection limit of approximately 1 ppb,
TCDL) was not detected beyond b.OOO feet downstream of the Minker area.
Concentrations ranged from a maximum of 272 ppb near the Minker area to
less tnan 1 ppb 7,400 feet downstream.
In 1985, biota and additional sediment samples were collected and analyzed
by the EPA. Twelve sediment samples were collected, approximately one
sample every half mile. TCDO was detected 1/2 mile downstream of the
M1 nicer area at concentrations as high as 36.3 ppb. (Tn-is was the closest
sample to the Minker area.) The next sampling location which was 1-mile
downstream of'the Minker area, and all sample locations farther downstream had
average TCDD concentrations of less than 1 ppb. (Detection limits were
generally in the range of 0.10 to 0.20 ppb.) The sampling location
farthest from the Minker area, 4.5 miles downstream, had an average TCDD
concentration of 0.3 ppb; this indicates that a small amount of TCDD may
be eroding to the mouth of the creek.
The 1985 biota sampling was conducted to determine if aquatic organisms
in Romaine Creek and in Saline Creek below the Romaine Creek confluence
had bioconcentrated TCDD. TCDD was detected in all the aquatic species
sampled (fish, crayfish, amphipods). TCDD concentration was typically
greater than 50 parts per trillion (ppt). Above Bubbling Springs,
Romaine Creek 1s an intermittent stream and does not have sufficient
aquatic habitat to support fish and crayfish.
Cleanup activity to date has included excavation of soils exceeding 1 ppb
TCDD at: the Minker area in 1986, which is the source of cne Romaine Creek
contamination. Warning signs have been posted along the contaminated
portion of Romaine Creek. A state-issued fishing advisory is in effect for
the Meramec River due to elevated levels of chlordane detected in fish
samples collected from the river.
COMMUNITY RELATIONS HISTORY
Section 117 of SARA provides that notice must be published and a brief •
analysis of the proposed plan be made available to the public. A reasonable
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opportunity for submission of oral and written comments must be provided.
The opportunity for a public meeting near the site is required regarding
the proposed plan. Any findings concerning compliance with federal and
state cleanup standards must be provided to the public.
A public comment period was held for the Romaine Creek Operable Unit
Feasibility Study (UUFS) and Proposed Plan from August 20 through
September 21, 1987. A public meeting was conducted September 10, 1987,
to discuss these documents and the Agency's tentatively selected alternative.
All documents released were made available for public inspection and
copying at EPA Public Information Centers located on Lewis Road, immediately
east of Times Beach, and at the intersection of Kiefer Creek Road and
Ries Road in Castlewood (Ballwin), Missouri. These EPA information
facilities provided the opportunity for public access to information six
days a week. An onsite EPA public information center will be established
and remain open during implementation of any remedial action at Romaine
Creek.
The opportunity for public participation has been provided prior to and
during all dioxin cleanup activities in Missouri since EPA began actively
investigating potential Missouri dioxin sites in 1982. Cleanup activities
to date have consisted of removal actions taken to reduce exposure to
dioxin-contaminated soils by containment and by excavation and secure storage.
Public meetings have been conducted prior to all removal activities
implemented since 1984 to solicit public comments so that the Agency
could be aware of and responsive to the public's concerns.
•Cleanup measures being addressed in this document represent interim
actions for the management of dioxin-contaminated sediments prior to
final management. Final management of dioxin-contaminaced materials is
being addressed separately, and was evaluated in the Feasibility Study of
Final Remedial Actions for the Minker/Stout/Romaine Creek site.
A public comment period was held for the Feasibility Study of Final
Remedial Actions for the Minker/Stout/Romaine Creek Site from August 8,
1986, until September 5, 1986. A public meeting was held on August 25,
1986, at a local public facility in order to discuss the alternatives
evaluated in the study and the Agency's proposed remedy. At the public
meeting it was announced that the only alternative in the study which the
Agency currently considered feasible to implement for final management of
contaminated soils was offsite thermal treatment within 50 miles of the
site. It was also announced that the State of Missouri had recommended
and suggested the evaluation of Times Beach as a location for offsite
thermal treatment, and that EPA was evaluating Times Beach as a possible
location for siting a mobile thermal destruction unit. It was announced
that a feasibility study to evaluate Times Beach as a potential location
for offsite thermal treatment would be completed and released for public
comment in January 1987.
ALTERNATIVES EVALUATION
SITE OBJECTIVES
General site-specific objectives are 1) to prevent or reduce long-term
human contact with soils containing dioxin at concentrations exceeding
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the action level whicn is determined to be protective of public health
and 2) to minimize the potential for offsite migration of dioxin. Operable
unit alternatives must be consistent with the final remedial action. An
objective of all alternatives involving treatment is to achieve destruction
and removal efficiencies (DKE's) which meet applicable or relevant and
appropriate regulatory criteria.
The Romaine Creek Operable Unit Feasibility Study evaluates removal of
soil dnd sediment exceeding an action level or target cleanup level of 1 ppb.
Federal and state health officials have determined that 1 ppb in a residential
area is a reasonable level at whicn to express concerns about public
health risks. Complete removal of all contaminated soil and sediment was
also evaluated.
INSCRIPTION OF ALTERNATIVES
A brief description of the operable unit alternatives is given in this
section. Five alternatives have been given consideration for the interim
remedy for Komaine Creek. Additional development, description, and
evaluation of each alternative is presented in the Romaine Creek Operable
Unit Feasibility Study.
Alternative 1: No Action
Under the no-action alternative, no additional remedial action-s. would be
taken at Romaine Creek.
Alternative 2: Limited Action
Limited action would involve implementation of site-use restrictions, as
deemed .necessary and posting of warning signs along the full length of
the creek, plus fencing at road crossings to limit public access. The
alternative would also Include annual monitoring of TCDD distribution
within Romaine Creek and monitoring for TCDD in nearby selected wells.
Alternative 3: Stabilization
This alternative would include the same scope items as described for
Alternative 2 plus the additional measures of quarterly monitoring and
1n-place stabilization of the sediments contaminated at levels greater
than 1 ppb. Stabilization would be accomplished using vegetation and
manufactured erosion control mats. As- previously described, the reach of
creek contaminated at levels exceeding 1 ppb lies within that portion
which is dry much of the year.
Alternative 4: Excavation to 1 ppb and Storage
Alternative 4 would involve excavation and temporary onslte storage of
all soils and sediments contaminated at concentrations exceeding 1 ppb,
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and implementation of a monitoring program similar to Alternative 2. It
is estimated that approximately 4,400 cubic yards of contaminated material
would be removed and stored during implementation of this alternative.
It is assumed that the excavated sediments would be stored in semi bulk
sacks placed in metal buildings, as has been aone by the EPA during
removal actions performed at other Missouri dioxin sites. A storage site
was not selected; however, it was assumed that the site would be adjacent
to the creek, protected from a lUO-year flood, and that it would be
relatively flat.
Alternative b: Complete Excavation and Storage
Alternative 5 would involve excavation and temporary onsite storage of
all sediments within Romaine Creek. A preliminary estimate made of the
sediment volume that would be stored during implementation of this alternative
is so,000 cubic yards. Storage would be as described for Alternative 4.
EVALUATION OF ALTERNATIVES
The five operable unit alternatives considered in the detailed evaluation
were compared to CERClA criteria for the selection of remedy. These
remedy selection criteria include the following:
0 Compliance with ARARs
9 Reduction of mobility, toxicity, or volume of •
waste
0 Short-term effectiveness
o Long-term effectiveness
0 Permanence
0 Implementability
0 Cost
0 Community and state acceptance
Table I presents an evaluation of eacn alternative against these evaluation
criteria. A discussion of each criteria and their attainment by each of
the alternatives follows:
Compliance with ARARs
Section 121(d) of CERCLA, as amended by SARA, requires that remedial
actions comply with requirements or standards under federal and state
laws for the protection of public health and the environment. Section 121(d)
allows a remedy to be selected that does not attain a level of control at
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TABLE 1. REMEDY SELECTION CRITERIA • ROMAINE CREEK
ALTERNATIVE
COMPLIANCE WITH
ARARs
REDUCTION OF
MOBILITY, TOXICITY,
OR VOLUME OF WASTE
SHORT-TERM
EFFECTIVENESS
LONG-TERM
EFFECTIVENESS
(Consistent with
(complete remedy which
(complies with ARARS.
1: No Action
(No reduction of (Risks to public health
(mobility, toxicity, or (and the environment
(volume. Some increase (remain at current
|in contaminated sediment(levels.
|volume requiring future |
(excavation may occur due)
(to contaminant migra- |
(tion. |
I I
(Existing contaminants
[would remain in place
(unless migration occurs.
(Risks to public health
(and the environment
(remain at current
(levels. Site boundaries
(may expand due to
(continued migration.
(Consistent with
(complete remedy which
(complies with ARARS.
2: Limited Action
(No reduction of (Low potential for
(mobility, toxicity, or (exposure to community
{volume. Some increase (or environment in excess
(in contaminated sediment(of current levels or
(volume requiring future (exposure to workers
(excavation may occur due(during implementation.
(to contaminant migra* (Implementation would
(tion. (require less than on*
(year.
(Monitoring program would
(detect contaminant origra-
jtion. Fencing would control
(access to contaminated por-
jtion of stream. Low OIM req-
juirements. Protection
(achieved immediately upon
(completion.
(Consistent with
(complete remedy which
(complies with ARARS.
•I-
I
3: Stabilization
(No reduction in toxic- (Greater potential for (Reduced potential for
jity. Volume of material (exposure to workers and (exposure to community and
(requiring eventual sxca-|community relative to (environment. Existing cor
|vation will increase duejalt. 2 due.ro soil dfst-jaminants remain in place
|to volume of stabilizat-jurbance. Disturbance of (High Q&H requirements to
(ion material. Mobility (wildlife ana increased (maintain vegetation. Reliab-
(would be reduced and (stream turbidity BOSS- jility of vegetative cover
(could be controlled withfible. Could be completed(uncertain. Vegetation may be
(adequate maintenance. (within 2 years. (difficult to establish.
(Consistent with
i (complete remedy which
(complies with ARARS.
I
4: Partial Excavation (Storage structures
(No reduction in toxic- (Increased potential for
(ity. Mobility controlled(exposure to workers and
(by containerization and (community due to soil
(secure storage. Volume (disturbance. Temporary
(of contaminated sediment(wildlife disturbance
(designed and constructed (fixed at current level, (and increased stream
(to RCRA standards. (Estimated 4,400 cy of (turbidity possible.
j (material would require (Could be conoleted
| (final management. (within 2 years.
(Exposure potential reduced
(to residential standards.
(Stream levels permanently
(reduced to less than 1 ppb.
(Potential bioaccumulation in
(non-fishable stream. Protec
|tion achieved immediately
(upon completion. Limited 0*M
(requirements for structures.
(No reduction in toxic- (Increased potential for
Iity. Mobility control led(exposure to workers and
(by containerization and (community due to soil
(secure storage. Volume (disturbance. Temporary
(of contaminated sediment(wildlife disturbance
(designed and constructed(fixed at current level, (and increased stream
(to RCRA standards. (Estimated 50,000 cy of (turbidity possible.
I (material would require (Implementation would
| (final management. (require 3-4 years.
(Consistent with
(complete remedy which
(complies with ARARS
I
Complete Excavation (Storage structures
(Exposure potential for coma-
(unity and environment elim-
jinated. No residual contam-
|(nation would remain.
(Potential bioaccumulation
(eliminated. Protection
(immediate upon completion.
(Limited 0*M requirements
(for storage structures.
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TABLE 1. REMEDY SELECTION CRITERIA - ROMAINE CREEK (cent.)
ALTERNATIVE
PERMANENCE
IMPLEMENTABILITY
COST
COMMUNITY AND
STATE ACCEPTANCE
|1: No Action
2: Limited Action
3 iilization
(4: Partial Excavation
I
5: Complete Excavation
(No direct impact
(on future management
(requirements.
(Volume of material
(requiring final manage-
|merit may increase or
(decrease due to contam-
jinant migration. '
(No direct impact
Jon future management
(requirements.
(Volume of material
(requiring final manage-
(ment may increase or
(decrease due to ccntam-
jinant migration.
n/a
| (Community desires that
(Total present worth: (Romaine Creek be cleaned
(up as soon as possible.
$0 (State recognizes need to
(initiate action.
Annual O&M cost: (No action not consistent
(with community and state
$0 (sentiment.
I
(Straightforward implem-
jentation. Uncertain
|reliability due to un-
|authorized site intrud-
jers. Access to affected
(private properties
(would be required.
(Does not represent perm-
janent fixation. Regular
Imaintenance would be
•I-
(Community may interpret
Total present worth: (as final action, and
(would object to implem-
$211,000 jentation from esthetic
(standpoint. Limited
Annual OSM cost: (Action not consistent
(with past state actions.
$21,000 j
Establishment of veget-
ation nay be difficult
in some areas. Erosion
•(required to maintain, thefmay occur during severe
(volume of soil requiring(storms. Access to
(final management at (private properties
(current level. Increase (would be required.
(In total volume due to j
(stabilization materials.|
(Total present worth:
$937,000
Annual. 32M cost:
(Permanently reduce
(levels in creek to
(below 1 ppb.
|Containerization
(would facilitate
(future handling.
(Implementation faciI it-
fated by proper selection Total
(of equipment. Reliabil
jity of storage struct-
(ures high. Access to
(private properties
(would be required.
I
Permanently remove (Removal of submerged
(existing contamination (sediments difficult. De- Total
(to background levels. (watering necessary.
jRecontamination possibleJAccess to many private
(from Minker site. (properties required.
(Containerization (Reliability of storage
(would facilitate (structures high. Insuf-
jfuture handling. jficient onsite area for
j (required structures.
$37,000
(Community may interpret
|as final action, and
(would object to need
[to access.property and
(disturb creek twice.
(Not consistent
(with past state actions.
I
present worth:
$4,488,000
Annual O&M cost:
$28,000
I
(Community would support
(removal of contamination
(from creek, but may ob-
jject to siting of stor-
jage structures.
(Consistent with past
state actions.
present worth:
$27,900,000
Annual O&M cost:
$22,000
I
(Community would support
(removal of contamination
(from creek, but may ob-
jject to siting of stor-
jage structures. Large
(number of required
(structures objectionable.
(Consistent with past
(state actions.
•I
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least: equivalent to a legally applicable or relevant and appropriate
requirement (AKAR) if the remedy selected is only part of a total remedial
action that will attain such a level of control when completed. The
operable unit alternatives evaluated in the feasibility study represent
only part of the-complete remedy for Romaine Creek. It is not necessary
for these alternatives to comply with all AKARs. The alternatives will,
however, be compared to ARARs and evaluated to determine the extent to
which each is consistent with a final remedy which attains ARARs.
All alternatives evaluated are consistent with final remedial actions
which involve treatment or disposal. A complete remedy involving the
treatment or disposal of dioxin-contaminated soils and sediment would
potentially meet all ARARs. The operable units evaluated are therefore
consistent with complete remedies which meet ARARs.
The land ban regulations governing the land disposal of dioxin-contaminated
waste:* are expected to go into effect in November 1988. Final management
of soils and sediments from Romaine CreeX will not occur before that
date. The land ban regulations state that dioxin-contaminated soils can
be land disposed if they pass the Toxicity Characteristics Leaching Procedure
(TCLP). Based upon existing sample results from Romaine Creek, it is
expected that the excavated, sediments would pass the TCLP test and be
exempt: from the dioxin land ban.
Permits are not required for onsite remedial actions at Superfund sites.
Although formal permits are not required, any action must meet the substantive
technical requirements of the permit process. Storage structures included
in alternatives involving excavation and interim onsite storage of contaminated
soils will be designed and constructed in compliance w--n the appropriate
substantive requirements of the Resource Conservation and Recovery Act,
as amended (RCRA).
Reduction of Mobility, Toxicity, or Volume of Waste
Section 121(b) of CERCLA, as amended, states that remed-'al actions involving
treatment which permanently and significantly reduce the volume, mobility,
or toxicity of hazardous materials are to be preferred over those not
involving such treatment. This evaluation criteria relates to the ability
of a remedial alternative to control or eliminate risks caused by the
mobility, toxicity, or volume of a hazardous waste.
Alternatives 1 and 2 would have no direct impact on the mobility, toxicity, or
volume of hazardous materials in Komaine Creek, however, failure to stabilize or
contain dioxin-contaminated sediments may result in expanded site boundaries
and an increased soil volume requiring future management.
Stabilization of contaminated areas in Romaine Creek would reduce the
potential for erosion and transport which currently exists. Implementation
of this alternative would result in an increase in the soil volume requiring
future management due to the volume of stabilization material.
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Alternatives involving the excavation and interim onsite storage of
contaminated soils would result in decreased potential for migration.
Mobility of excavated material would be eliminated due to containerization
and secure storage. Migration of contamination not removed from the
creek could continue to occur. Excavation of sediments exceeding 1 ppb
would be expected to result in the permanent reduction of contaminant
concentration in Komaine Creek sediment to levels below 1 ppb. It is
anticipated that no subsequent excavation would be necessary to maintain
sediment concentrations below 1 ppb. Complete excavation would remove
all sediment from Romaine Creek, eliminating the potential for additional
migration of existing contamination in Romaine Creek. As discussed later
in this document, however, some degree of contaminant migration may occur
from the adjacent Minker area, where soils exceeding 1 ppb TCOO were
removed.
Short-Term Effectiveness
Short-term effectiveness measures how well an alternative provides protection
of the environment, community, and workers during construction, and the
time required for implementation.
Short-term risk to public health and the environment would remain at
current levels for Alternative 1. However, there would be no increase in
risk to workers due to construction activity or disturbance of contaminated soil
During implementation of Alternative 2, there would be low potential for
exposure to workers and no significant increase in exposure to the community.
or environment. Stabilization of the creek bed would result in greater
potential for worker exposure due to soil-disturbing activities. Soil
disturbance would increase the potential for exposure to the community
and could temporarily disturb wildlife and increase stream turbidity.
Excavation and interim storage of contaminated sediments would also
involve soil disturbance and related exposure opportunities. This exposure
potential could be mitigated by adequate dust control and monitoring.
Severe storms may spread contamination during implementation of stabilization
or excavation activities. Complete excavation of Romaine Creek sediments
would involve a larger area with greater opportunity for wildlife disturbance
and community and worker exposure. Disturbance of submerged sediments
during removal in the perennial reach of the stream would increase the
turbidity of lower Romaine Creek and temporarily increase sediment loading
into the Meramec River. Exposure potential would continue during dewatering
of submerged sediments. The potential negative effects of these possible
events could be minimized and controlled by design and "Implementation of
protective measures such as daily cover of exposed areas and removal of
submerged sediments during low-flow periods.
Long-Term Effectiveness
Long-term effectiveness addresses the long-term protection and reliability
that an alternative affords. This includes the risk to the community
once the remedy is in place, risk to workers during operation and maintenance
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(0AM), environmental risk due to residual hazardous substances, long-term
reliability, 0AM requirements, time required to achieve protection, and the
difficulty in detecting and mitigating problems with the completed remedy.
Existing contamination would remain in place for the no-action and limited-action
alternatives. Site boundaries could potentially expand due to contaminant
migration through erosion. If this occurred, the resulting increased
volume of contaminated sediment would increase the scope and cost of
future management. Excavation of sediments in the perennial portion of the
stream would be much more difficult than in the intermittent section, if
migration occurred to that extent.
Limited action would.provide a monitoring program to detect the spread of
contamination, and fencing to control access to contaminated portions of
the creek. Fencing and posting of the creek may not prevent all site
intruders from access. Limited action would have low 0AM requirements,
could be easily inspected, and repairs would be straightforward. Limited
action would achieve its full degree of protection immediately upon
implementation of the remedy, as would all of the alternatives evaluated.
Stabilization of the creek would reduce exposure potential to the community
and environment by controlling dispersion of contaminated soil due to
erosion by wind and water. Existing levels of contamination would remain
in place. Bioaccumulation could continue to occur at a reduced rate.
Operation and maintenance requirements would be substantial in order to
maintain vegetation in all contaminated portions of the creek. Quarterly
O&M may not be sufficient to maintain vegetation in some areas. Ineffectiveness
of th« stabilization could result in migration of contaminants, expanded
site boundaries, and increased sediment volumes requiring future management.
Workers performing O&M activities could potentially be exposed to elevated
levels of TCDO. If contaminants exceeding a level of concern were transported
to the perennial portion of the creek, excavation would be more difficult.
Excavation of contaminated sediment exceeding 1 ppb would reduce exposure
potential to residential standards. Bioaccumulation of TCDO in biota
could potentially continue to occur following excavation of sediments
exceeding 1 ppb, but the rate of bioaccumulation would be expected to be
substantially reduced from current levels. It is expected that reduction
of contaminant levels in Romaine Creek to levels below 1 ppb would result
in a reduction in contaminant levels in Romaine Creek biota. At the present
time, bioaccumulation of dioxin in biota does not represent a significant
risk to human health, since Romaine Creek and the extreme lower portion
of Saline Creek do not support private or commercial fishing. Romaine Creek
waters eventually reach the Meramec River, which currently has a state-issued
fishing advisory in place due to elevated levels of chlordane detected in
Meramec River fish. Contaminated biota in Romaine Creek and the Meramec River
are therefore not expected to enter the human food chain or represent a
current risk to public nealth.
Limited 0AM requirements would be associated with maintaining the storage
structures for both excavation alternatives. There would be no 0AM requirements
for the creek, although annual monitoring of the area is included in the
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partial excavation alternative evaluated In the OUFS. Problems with the
remedy could easily be detected during Inspection of the storage structures
and repaired. The risk of system failure Is very low.
Excavation and interim onsite storage of all sediments in Romaine Creek
would provide the maximum degree of long-term protection to public health
and the environment of the alternatives evaluated. No residual contamination
would remain in the creek. Exposure potential for the community and environ-
ment and the potential for bioaccumulation in the creek would be eliminated.
Contaminant concentrations in affected biota would be expected to eventually
return to background levels if no recontamination of the creek occurred.
Limited U&M requirements would be associated with the storage structures.
Problems with the remedy could be easily detected during inspection and
repaired.
Permanence
The criteria of permanence 1s similar to long-term effectiveness, but
with an emphasis on the need for management of treated residuals and untreated
wastes. The operable unit alternatives evaluated represent interim
measures which can be Implemented prior to final management of the contaminated
soils. Permanence of each operable unit alternative concerns the extent
to which future management of contaminated soils will be necessary.
No action and limited action will not control migration of contaminated
sediments, which could result in expanded site boundaries. A removal
action Involving excavation of dioxin-contaminated soils exceeding 1 ppb
has been completed at the Minker portion of the Minker/Stout/Romaine
Creek site, which was the primary source of contamindf on Into Romaine Creek.
It 1s therefore likely that dioxin concentrations 1n upper Romaine Creek will
decline due to the erosion of contaminated sediments to downstream areas.
Implementation of the no-action and limited-action alternatives will have
no direct impact on future management requirements, although the volume of
sediments requiring management could either decrease due to washout of
contaminated areas or Increase due to downstream migration of contamination.
Stabilization could be effective at controlling migration of contaminated
sediment, thereby fixing the volume of sediment which is contaminated 1n
excess of 1 ppb at the current level. Tnere would be some increase in future
management requirements due to the need to manage the stabilization
materials.
Partial excavation of sediment 1s expected to result in the permanent reduction
of contaminated levels to below 1 ppb. Future management of soils would be
facilitated due to containerization of wastes. Complete excavation of
contaminated sediments would permanently remove all existing contamination
from Romaine Creek, but residual contamination at levels less than 1 ppb may
continue to erode from the Minker area into Romaine Creek. It 1s not
expected that this migration will result 1n recontamination of the creek
to levels exceeding 1 ppb.
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Implementability
This criteria measures the technical difficulties, reliability, and
availability of each alternative. Implementability also involves the
administrative feasibility of each alternative. No permits would be
required for any of the actions evaluated since CERCLA onsite actions are
exempt from permitting requirements by law.
The implementability criteria does not apply to the no-action alternative,
since no measures would be taken to mitigate the contamination. Implementation
of limited action would be straightforward. Access to private properties
adjacent to the affected portion of the stream would be required, and may
1n some cases be difficult to obtain. The reliability of the limited
action alternative is not certain. Site intruders could ignore warning
signs and scale or avoid fences. Contamination may migrate downstream
resulting in additional areas requiring access restrictions.
Stabilization of contaminated areas would be more difficult to successfully
Implement than the no-action or limited-action alternatives. Many contaminated
areas may not support vegetation. The reliability of stabilization would
be Impacted by severe storms which could disrupt the stabilized areas.
Access to private properties adjacent to contaminated portions of Romaine Creek
would be required.and may be difficult to obtain. The construction of access
roads would be required along the length of the creek .impacted for stabilization,
and also for partial excavation and complete excavation alternatives. This
may increase the difficulty in obtaining access from adjacent property
owners.
Imp lenient at ion of the partial excavation alternative could be facilitated
by appropriate construction techniques. Vacuum equipment could be used
to selectively remove pockets of sediment disposition within the creek.
The reliability of partial excavation would be very high upon completion.
The storage structures would last indefinitely if properly maintained.
Implementation of the complete excavation alternative would be more difficult
since submerged sediment would be removed from the creek. Dewatering of
the dredged sediment would be a complex operation probably requiring
several acres of land currently in private ownership. Difficulty would be
expected 1n obtaining access on private property for construction of access
roads, excavation activities, and dewatering.
Cost
The total present worth cost of each alternative is presented in Table I.
Costs listed for Alternatives 4 and b involving excavation and interim
storage include the cost of removal and decontamination of the storage
structures upon Implementation of final management of sediment. Also
included in Table I is the .estimated annual Operation and Maintenance (OSM)
cost associated with each alternative.
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Community and State Acceptance
Duriny past public meetings conducted for other portions of the Mlnker/Stout/
Romaine Creek site and other nearby dloxin sites, tne community was given
the opportunity to express their preference for management of contaminated
soils. Affected residents are in general agreement that the contaminated
soil should be excavated and transported offsite for treatment or disposal.
At tne present time, there is no offsite treatment or disposal facility
capable of managing the dioxin-contaminated sediments. Interim storage
is therefore necessary until an offsite management option develops. The
community is likely to be supportive of excavation of contaminated sediment
and removal of the associated risk to public health. Given the absence of
an offsite management option, the public will probably accept interim
storage as the only alternative available at this time. Interim storage is
consistent with the community supported final management option of offsite
treatment or disposal. Some local objection can be expected near the
location where the required storage structures are sited.
Several removal actions have been completed in the recent past involving
excavation and interim storage of contaminated soils at nearby Eastern
Missouri dioxin sites. The State of Missouri has in the past been supportive
of these actions if they achieve adequate protection of public health and
the environment. During the public comment period, the state expressed Its
support for the excavation and interim storage of sediments exceeding 1 ppb
in Romaine Creek.
. ' SELECTED REMEDY
DESCRIPTION OF THE SELECTED REMEDY
The interim remedy which the Agency will implement as an operable unit
remedial action involves excavation of creek sediments exceeding 1 ppb
2,3,7,8 TCDO. This remedy is developed and described in detail as Alternative
in the Romaine Creek Operable Unit Feasibility Study.
Excavation of Romaine Creek soils and sediments exceeding 1 ppb will be
performed using vacuum equipment, or other appropriate means of selectively
removing pockets of potentially contaminated sediment deposition. An
effort will be made to minimize the amount of material removed from
Romaine Creek, while maintaining the assurance that soils and sediment
exceeding 1 ppb are not left in place. Minimizing the volume of sediment
removed from Romaine Creek limits the extent of environmental disturbance
within the creek. Minimizing the removed sediment volume also reduces
the required interim storage space and associated final management costs
for the removed material. Any identified technology or procedure capable
of reducing the amount of material removed from Romaine Creek will be
investigated during the design phase. These technologies include, but
are not limited to, innovative excavation techniques and particle separation
technologies capable of separating the contaminated fine materials from
uncontaminated rocks and other coarser materials.
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All concentrations within Romaine creeic will be determined at the 95 percent
confidence level using the procedure developed in 1984 for cleanup of
other eastern Missouri dioxin sites. This procedure has undergone peer
review and approval by Federal and State health agencies including the
Centers for Disease Control/ Center for Environmental Health, Environmental
Protection Agency, Missouri Division of Health, and the Missouri Department
of Natural Resources. This procedure determines the maximum surface contaminant
level in unit areas of approximately b,uOO square feet or smaller at the 9b
percent confidence level.
txcavated soil and sediment will be containerized in woven polypropylene,
polyethylene-lined bulk handling sacks similar to those currently and
previously in use at eastern Missouri dioxin sites, including the Minker,
Cashel, and SulHns portions of the Minker/Stout/Komaine Creek site.
These bulk-handling sacks will be loaded by hopper and transported to
fully enclosed, temporary storage structures constructed onsite. Storage
structure design will be similar to those in use at other eastern Missouri
dioxin sites. One 50-foot by 100-foot building has a capacity of approximately
1,100 cubic yards of containerized material. It is estimated that up to
four such structures will be required to store the volume of contaminated
material anticipated to be removed from Romaine Creek. Storage structures for
contaminated material excavated from Romaine Creek will be located on the
former Edwards property. The storage structures will be protected from
flooding, and an effort will be made to minimize their adverse aesthetic impact.
Excavated materials will be placed in interim storage until a final
management .option can be selected. If a fi.nal management alternative
becomes available and is selected in a separate Record of Decision for
material removed from Romaine Creek, it is possible thac interim storage
of the excavated material will not be necessary, and that contaminated
soil and sediment can be taken directly to the location where final
managenent is available. This decision would be documented in a subsequent
Record of Decision for final management of dioxin-contaminated materials
from the Minker/Stout/Romaine Creek site.
The interim remedy also includes a provision for annual monitoring. This
monitoring will verify that the interim remedy remains protective of
public health and the environment. Contaminant levels will be monitored
in sediment and biota. Area wells will also be sampled to confirm that
area groundwater used for domestic purposes does not become contaminated.
If TCDD levels are consistently below a level of concern for public health
and the environment, this monitoring may be discontinued.
RATIONALE FOR PREFERENCE
The selected interim remedy is preferred over the no-action and limited-action
alternatives primarily because leaving contaminated sediment in place
does not provide adequate protection of human health or the environment.
Access to contaminated portions of the creek by nearby residents or
visitors would not be prevented by either no-action or limited-action
alternatives. Exposure via direct contact and ingestion would continue
to occur in excess of a level of concern for protection of human health
-in residential areas recommended by federal and state health agencies.
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Naturally occurring erosion processes would be expected to gradually
reduce contaminant levels in Romaine Creek. This erosion would result in
the more highly contaminated sediment being transported downstream where
it could become available to additional environmental and human receptors.
Existing contaminant levels in Komaine Creek are too high to allow natural
erosion processes to transport contaminated sediment downstream in an
unmanaged process. It is expected that natural attenuation of contaminant
levels to a level considered protective of public health and the environment
could potentially take many years. Exposure of the public and environmental
receptors to levels considered unsafe could continue until sediment
concentrations are greatly reduced. Allowing natural processes to reduce
sediment concentrations does not provide adequate protection of human
health or the environment.
Stabilization of contaminated sediments is not being proposed due to the
uncertainty of successful implementation, high OiM requirements, and
because final management of the contaminated sediments would involve future
construction activities which would disturb the creek and adjacent property
owners along the contaminated portion an additional time. Difficulty may
be encountered in acquiring easements or other types of access to private
properties in order to perform regular maintenance. Excavation of contaminated
sediments would permanently remove contaminants from Romaine Creek and
eliminate the need to' perform additional construction activities prior to
final management of contaminated sediment.
STATUTORY DETERMINATIONS
Removal and temporary onsite storage of soils and .sediment exceeding 1 ppb
in Romaine Creek attains the objectives of- the interim -emedy and satisfies
the remedy selection criteria. The objectives of the ^nterim remedy
identified in the Romaine Creek Operable Feasibility Study are to protect
human health and the environment, provide compatibility with potential
final remedial actions, and be cost-effective. Protection of human
health and the environment is provided by mitigating the potential for
human and environmental contact with contaminated sediment and reducing
the potential for continued downstream erosion of contaminated sediments.
The proposed interim remedy attains protectiveness objective by isolating
the containerized contaminated sediment in a secure storage facility,
thereby eliminating the potential for human or environmental contact with
contaminated material exceeding 1 ppb TCDO. Some migracion of sediments left
in place at concentrations less than 1 ppb may continue to occur, but this
migration is not expected to result in the development of contaminant
levels exceeding a level of concern for protection of public health and the
environment in the creek. It is anticipated that natural degradation and
erosion processes will result in the gradual reduction of contaminant
levels in the creek to near background levels.
The selected interim remedy also attains the objective of compatibility
with final remedies. The interim remedy is compatible with potential
offsite treatment or disposal options. Future handling of the contaminated
material will be facilitated by containerization. The interim remedy is
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not compatible with final remedial action alternatives, involving in-place
containment or treatment. In-place alternatives, however, do not compare
favorably to offsite alternatives for final management of contaminated
sediment, and have not been recommended by the Agency for implementation
at Komaine Creek.
Although a final remedy has not been selected for contaminated soils and
sediment from the Minker/Stout/Romaine Creek site, the Agency has proposed
offsite thermal treatment for final management of this material. This
proposed final remedy is supported by SARA, which establishes a statutory
preference for remedies wnich utilize treatment technologies that result
in the permanent reduction in toxicity, mobility, or volume of the hazardous
mater? a 1.
The selected remedy has been determined to be the most cost-effective operable
unit remedial alternative which provides protectiveness. Only the two
removal alternatives evaluated will assure the continued protection of
public health and the environment. Complete excavation of all sediments
in Komaine Creek cannot be justified at the additional cost because both
removal alternatives reduce TCDD concentrations below 1 ppb which assures
protection of public health and the environment. Complete excavation of
sediments would result in excessive disruption of the environment along
the entire length of Romaine Creek and would be very difficult to implement.
Removal of all sediment in Romaine Creek may not permanently remove all
contamination from the streambed since soil with TCDD concentrations less
than 1 ppb may continue to erode into the creek from the Minker area.
The 1 ppb action level utilized during the cleanup, of the'Minker area
does provide protection of human health in Romaine Cree<, where consumption
of contaminated biota 1s not expected, to represent an additional public
health risk.. The Missouri Department of Conservation has stated Romaine Creek
does not support fishing and adjacent" residents have confirmed this by
reporting that no fishing has been observed. Romaine Creek flows into
Saline Creek 0.2 miles upstream o'f the Meramec River. The Meramec River
is currently under a state-issued fish advisory due to elevated chlordane
levels in the fish. TCOO levels detected in Meramec River biota to date
have not, however, exceeded a Food and Drug Administration (FDA) advisory
level for consumption of fish from the Great Laices of bO parts per trillion
(ppt). Consumption of contaminated fish from Romaine Creek or the Meramec River
is therefore not expected to be a significant pathway of human exposure.
Removal of soil exceeding 1 ppb at the Minker area has eliminated the source
of highly contaminated sediment into Romaine Creek. It is anticipated
that following removal of sediment exceeding 1 ppb in Romaine Creek,
residual contaminant levels in the creek will gradually decline due to
naturally occurring degradation and erosion processes. The selected
Interim remedy includes annual monitoring of Komaine Creek following
removal of sediments exceeding 1 ppb in order to monitor residual contaminant
levels and detect any potential migration or accumulation of contaminated
sediments. It is anticipated that contaminant levels will gradually
return to background.
Bioaccumulated contaminant levels in biota are expected to decline following
removal of sediment exceeding 1 ppb. As residual sediment concentrations
are further reduced through natural processes, a corresponding decline in
biota contaminant levels is expected. Annual monitoring of sediment and
biota will monitor the reduction in contaminant levels following implementation.
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