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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                                    11
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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                                    13
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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                                    15
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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                                    16

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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