United States
Environmental Protection
Agency
Office of
* Emergency and
Remedial Response
E PA/ROO/R08-89/023
September 1989
&EPA
Superfund
Record of Decision
Burlington Northern
(Somers Plant), MT
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50272-101
REPORT DOCUMENTATION i. REPORT NO. 2.
PAGE EPA/ROD/R08-89/023
4. Tide and Subtitle
«PERFUND RECORD OF DECISION
rlington Northern (Somers Plant), MT
rst Remedial Action - Final
7. Author(s)
9. Performing Organization Name and Address
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
X Recipient's Accession No.
5. Report Date
09/27/89
&
8. Performing Organization Repl No.
10. Project/Task/Work Unit No.
11. ContracqC) or Grant(G) No.
(C)
(C)
13. Type of Report & Period Covered
800/000
14.
15. Supplementary Nolea
16. Abstract (Umit: 200 words)
The 80-acre Burlington Northern (Somers Plant) site is a former railroad tie treatment
facility in Somers, Flathead County, Montana. Residential areas border the site on
three sides and wetlands are located along Flathead Lake, 1,200 feet to the east, and in
a slough area adjacent to the plant. Flathead Lake is currently the source of the
rs municipal drinking water supply. Burlington Northern operated the treatment
it from 1901 to 1986 and generated wastewater primarily consisting of stream
condensate containing, zinc chloride and creosote, which was discharged to a lagoon south
of the treatment building. Overflow from the lagoon flowed through an open drainage
ditch to a pond which formed in a swamp area adjacent to the ditch, and eventually into
the lake. Contaminated soil and sediment areas in addition to the drainage ditch, swamp
pond, and lagoon include a drippage area along the railroad tracks where treated ties
were removed from the treatment building, a slough area where treated ties were stored,
and a beach area extending into Flathead Lake. Ground water in the vicinity of the
lagoon and the swamp pond is also contaminated. In May 1985 EPA performed an emergency
removal action and removed approximately 3,000 cubic yards of contaminated soil and
100,000 gallons of contaminated water from the swamp pond and drainage ditch areas. The
excavated areas were backfilled and covered, and excavated soil was transferred to an
offsite RCRA-regulated facility to await treatment. (See Attached Sheet)
17. Document Analysis a. Descriptors
Record of Decision - Burlington Northern (Somers Plant), MT
First Remedial Action - Final
Contaminated Media: soil, sediment, gw
Key Contaminants: organics (PAHs, phenols), metals (zinc)
b. Identifiers/Open-Ended Term*
c. COSATI Held/Group
^•kulabifity Statement
19. Security dase (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
121
22. Price
(See ANSI-Z39.18)
See Instructions on Remrtt
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R08-89/023
Burlington Northern '(Sbmers Plant), MT
First Remedial Action - Final
Abstract (continued)
Contaminated water was treated onsite to recover usable materials. The primary
contaminants of concern affecting the soil, sediment, and ground water are organics
including creosote constituents such as PAHs and phenols, and metals including zinc.
The selected remedial action for this site includes excavation and onsite biological
treatment of 11,700 cubic yards of contaminated soil and sediment from all source areas
except the beach area; onsite restoration or replacement of wetlands areas; installation
and operation of an innovative hot water flushing system and a water treatment system
using ozone/uv or peroxide/uv in the lagoon and swamp pond areas to treat creosote
contaminated ground water, and in-situ biological treatment to degrade residual
contaminants in the ground water and contaminants adsorbed onto the aquifer matrix;
ground water will be reinjected or discharged to a POTW; ground water monitoring; and
implementation of temporary institutional controls to restrict ground water use. The
estimated total present worth cost for this remedial action is $12,031,000, which
includes an annual O&M cost of $661,000 for years 1-2, $811,000 for years 3-10, and
$72,000 for years 11-30. The present worth cost
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Administrative Record ^^^^_^ 0100622
Sf File Number _
j *4*a^_
-' ^=ffl^!«&^S
U.S. EPA REGION VIII
MONTANA OPERATIONS OFFICE
t ..
RECORD OP DECISION ^ -••-
' *-*£; '&i...?4- • -';!X-»s<: •'.-.. •..••••'>
-' 'V +/>V' ".....'•, , •''J'j;.:-.-'
BURLINGTON NORTHERN (SOMERS PLANT) SUPERPUND SITE
FLATHEAD COUNTY; MONTANA
SEPTEMBER 1989
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0100623
RECORD OF DECISION
DECLARATION
SITE NAME AND LOCATION
Burlington Northern (Somers Plant)
Flathead County
Somers, Montana
STATEMENT OF BASIS AND PURPOSE
This decision document represents the U. S. Environmental
Protection Agency's selected and contingency remedial actions for
the Burlington Northern (Somers Plant) Superfund Site ("the
Site"), in Somers, Montana. This document is developed in
accordance with the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), as amended by
the Superfund Amendments and Reauthorization Act of 1986 (SARA),
42 U.S.C. Section 9601, et seq. (Superfund) and the National ,
Contingency Plan (NCP), 40 C.F.R. Part 300. This decision is
based on the administrative record file for the Site.
By signature below, the State of Montana concurs in this
Record of Decision. All determinations reached in the Record of
Decision were made in consultation with the State of Montana,
which has participated fully in the development of this Record of
Decision.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from
this Site, if not addressed by implementing the response action
selected in this Record of Decision, may present an imminent and
substantial endangerment to public health, welfare, or the
environment.
DESCRIPTION OF THE REMEDY
This response action is anticipated to be the final action
for the Site. Other actions at the Site included the 1985
Superfund emergency removal in the swamp pond area (see Figure 3
in the Record of Decision Summary for locations of areas of the
Site), after it was determined to constitute an imminent and
substantial hazard to Flathead Lake, and the closure in 1988 of
two wastewater impoundments at the Site under State Resource
Conservation and Recovery Act (RCRA) authority.
This response action addresses the remaining contamination
by remediating soils, sediments and ground water, all of which
have been determined to pose a potential threat to human health
and the environment. The selected remedy addresses the principal
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0100624
threats by removing the potential for direct contact with soils,
by reducing the impact of the soils and sediments on ground water
and surface water, and by treating the ground water.
Soils and Sediments
The major aspects of the selected "source control" or soil
component of the remedy include:
o Excavation of approximately 11,700 cubic yards of
contaminated soils and sediments. Volumes to be
excavated include soils above the water table from the
CERCLA lagoon, drip track, drainage ditch and beneath
the retort building as well as sediments from the
slough.
o On-site biological treatment of excavated soils.
o Restoration and/or replacement of wetlands lost during
remedial action and those lost during the 1985
emergency action. The restoration/replacement will be
conducted in consultation with the U.S. Department of
the Interior.
Ground Water
The major aspects of the "migration control" or ground water
component of the selected remedy include:
o Installation and operation of an innovative hot water
flushing and water treatment system to remove and treat
available free creosote contamination from the water
table aquifer in the CERCLA lagoon and swamp pond
areas.
o In-situ biological treatment to degrade both
contaminants adsorbed onto the aquifer matrix and
residual contaminants dissolved in the ground water.
Ground Water Restrictions
Currently, there are no drinking water supply wells in the
affected portions of the water table aquifer. However,
institutional controls designed to prohibit the construction of
new wells downgradient from the CERCLA lagoon and in the swamp
pond area will be implemented and maintained until ground water
quality returns to acceptable levels.
Monitoring
The ground water component of the selected remedy will
require monitoring to assure that treatment is effective and that
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010C625
treatment proceeds until risJc-based cleanup levels have been
achieved and maintained. In addition, monitoring of the town's
proposed new municipal wells in the bedrock aquifer will be
instituted if testing indicates that drawdown in these wells
could cause the contaminated water table aquifer to affect the
municipal supply. The municipal wells are expected to be
installed and tested in the fall of 1989.
Contingency Remedies
The selected ground water component of the remedy involves
two innovative technologies: hot water flushing and in-situ
biological treatment. These technologies are expected to be
successful at the Site. However, because of their unproven
nature under the Somers hydrogeologic conditions, these
technologies will require pilot testing to determine their
effectiveness prior to full-scale implementation.
Contingency Remedy A. If EPA determines, based on pilot
testing, that ground water remediation is not practicable, soils
will be excavated to a depth of approximately 20 feet in the
swamp area and to approximately 30 feet in the CERCLA lagoon
area, and downgradient. This excavation will remove the source
of ground water contamination both above and below the water
table, in addition to the excavation areas outlined in the
selected remedy. In this case, institutional, controls designed
to prevent the construction of drinking water wells downgradient
from the CERCLA lagoon will be implemented and maintained until
natural degradation returns the aquifer to a usable condition.
Under this contingency, the excavated soils will be incinerated
on-site.
Contingency Remedy B. If, based on pilot testing, EPA
determines that ground water remediation would only be
practicable in the area of the CERCLA lagoon but not in the swamp
area, most likely due to lower permeability aquifer materials,
the swamp area soils will be excavated to a depth of
approximately 20 feet, in addition to the excavation areas
outlined in the selected remedy. The ground water component of
the selected remedy will then be implemented in the CERCLA lagoon
area only. Under this contingency remedy the soils will also be
incinerated on-site.
DECLARATION
The selected remedy and all the contingency remedies are
protective of human health and the environment, attain and comply
with Federal and State requirements that are legally applicable
or relevant and appropriate to the remedial action, and are cost-
effective. The selected remedy satisfies the statutory
preference for remedies which employ treatment that reduces
toxicity, mobility or volume as a principal element and utilize
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0100626
permanent solutions and alternative treatment technologies to.the
maximum extent practicable. Although Contingency Remedy A also
involves treatment of soils, this remedy would not satisfy the
statutory preference for treatment as a principal element of the
ground water component of the remedy to the extent that ground
water contamination downgradient from the CERCLA lagoon would not
be treated.
Because the remedy will take longer than five years to reach
health-based cleanup levels and because contaminated beach
sediments will be left in place, a review will be conducted five
years after commencement of the remedial action. The review is
to ensure that the remedy continues to provide adequate
protection of human health and the environment.
Signature
James 3^. S£herer£/ Date
Regiona-JTAdministrator
U.S. EPA Region VIII
In Concurrence
Donald E. Zlzzjthi, Director Date*
Department of Health and Environmental Sciences
State of Montana
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oiooe;:?
TABLE OF CONTENTS
RECORD OF DECISION SUMMARY
Chapter Page
I • Site Description 7
II Site History and Enforcement Activities 8
III Highlights of Community Participation 10
IV Scope and Role of Response Action 1 1
V Site Characteristics 12
VI Summary of Site Risks 18
VII Description of Alternatives 26
VIII Summary of the Comparative Analysis of
Alternatives 35
IX The Selected Remedies 40
X Statutory Determinations 46
XI Documentation of Significant Changes 49
Bibliography 52
Attachments
A. Applicable or Relevant and Appropriate Requirements
B. The Responsiveness Summary
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OIOCG:-:S
RECORD OF DECISION SUMMARY
I. Site Description
The Burlington Northern (Somers Plant) Superfund Site (also
commonly referred to as the Burlington Northern Somers Tie Plant
or the Glacier Park Company - Somers Tie Treatment Plant,
hereinafter referred to as "the Site") is located in northwestern
Montana in the unincorporated town of Somers, Flathead County
(Figures 1 and 2). Fewer than 1,000 residents live in the
community. The Site occupies approximately 80 acres within the
community. Residential areas abut the Site on three sides.
Areas known to be affected by contamination from the tie plant
extend from the plant to the shoreline of Flathead Lake, a
distance of approximately 1,200 feet. In addition, beach
sediments contaminated by plant discharges extend approximately
150 feet into Flathead Lake. The Site is located partially in
the floodplain of Flathead Lake. Flathead River enters Flathead
Lake approximately five miles east of Somers. Portions of the
Site along Flathead Lake and in a slough area adjacent to the
plant are wetlands. Ground water flows from the tie plant toward
the lake and slough.
The Somers community is located in the Flathead Valley
surrounded by the Rocky Mountains of western Montana. Flathead
Lake and Glacier National Park (located approximately 30 miles to
the north) are important recreational areas. The Flathead Valley
economy depends primarily on lumber, farming and tourism.
Flathead Lake covers an area of 300 square miles and is used for
hydroelectric power generation at Kerr Dam in Poison, Montana.
The lake is also used for recreational fishing and boating. The
local beach area, which is part of the Site, was formerly used as
a swimming beach, although it was closed to public access in 1985
by the property owners because of liability concerns. Most of
the southern half of the lake area and shoreline is contained
within the Flathead Indian reservation. A Federal Waterfowl
Production Area occupies much of the north shore of Flathead Lake
east of Somers. Waterfowl also breed in the slough area adjacent
to the tie plant.
Flathead Lake is currently the source of the Somers
municipal drinking water supply. The Somers Water District has
indicated its intention to convert to a bedrock aquifer drinking
water source in 1989. A bedrock well at the local school located
approximately 1/4 mile north of the tie plant currently is the
only well in Somers which is used as a source of drinking water.
Six residences in Somers have private wells used for purposes
other than drinking water. One of the six wells is completed in
bedrock, the other five are completed in the shallow water table
aquifer. None of these wells has thus far been shown to be
affected by contamination from the site.
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FIGURE 1
010CG29
FLATH€AD COUNTY
Regional Location
of BN - Somers Site
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FIGURE 2
URLINGTON NORTHERN RAILROAQ
&OMERS Hil TREATMNT PLANT:
o
SCALE 1:24,000
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0100631
The main structures on the tie plant property include an
office building, a retort building (which housed the wood
treating equipment), a boiler house, three large insulated
creosote product storage tanks and miscellaneous support
buildings. Three wastewater impoundments and one sanitary lagoon
were or are also located on site. The wastewater impoundments
are discussed in the following section.
II. Site History and Enforcement Activities
The Somers tie plant was operated by Burlington Northern
between 1901 and 1986. The plant treated railroad ties and other
miscellaneous lumber products to protect the materials from
weathering and insects. Treatment fluids used by BN included
zinc chloride, chromated zinc chloride and creosote/petroleum
preservative mixtures. The treatment process generated
wastewater primarily consisting of steam condensate containing
zinc chloride or creosote. Other sources of process generated
wastewater were floor and shop washings, drippage from ties
pulled out of the retort and drippage from treated ties in
storage. An average of 350 gallons of wastewater were discharged
per day. Approximately 1,000 pounds of sludge from the retort
was generated every one and a half to two years (ReTec 1989).
Prior to 1971, BN discharged wastewater to a lagoon located
immediately south of the retort building (the "CERCLA lagoon").
Overflow from this lagoon discharged through an open ditch into
Flathead Lake. Sometime prior to 1946, a pond formed in the
swamp area (the "swamp pond") adjacent to Flathead Lake and waste
material discharged through the open ditch accumulated here. The
final disposition of retort sludge is uncertain. Some was
reported to have been used to patch holes in local roads. The
locations of the major, presently known disposal areas at the
Site are shown in Figure 3.
BN abandoned the CERCLA lagoon and ditch in 1971 when the
company constructed two new wastewater holding impoundments (the
"RCRA impoundments"). In 1984 BN implemented a recycling system
and stopped all wastewater discharges.
In February, 1984, the Montana Department of Health and
Environmental Sciences (MDHES) sampled the Site soils. Based on
the results of this investigation, the Site was proposed for
inclusion on the Superfund National Priorities List in October
1984 (49 FR 40320, October 15, 1984). The proposed listing cited
potential negative effects on Flathead Lake and the water supply
for the town of Somers which is drawn from the lake.
In May, 1985, EPA, BN and Sliters (a corporation which owns
a portion of the site) signed an Administrative Order on Consent |
(Docket No. CERCLA-VIII-85-02) providing for an Emergency Removal^
action in the area of the swamp pond adjacent to Flathead Lake.
8
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FIGURE 3
flip-Hap Dlk*
Location ol Oltposal Areas at the Somers Tl« Plant
Source: Remediation Technologies (1989), Volume 1
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01096
o *s
The area was determined to pose an imminent and substantial
hazard to Flathead Lake because of the presence of heavy creosote
contamination in water and soil located within 20 feet of the
shoreline. Pursuant to the 1985 Administrative Order, BN removed
approximately 3,000 cubic yards of the most heavily contaminated
soils and over 100,000 gallons of contaminated water from the
swamp pond area and from a portion of the drainage ditch. The
excavated areas were backfilled with clean soil and rip rap was
installed along the lakeshore. The excavated materials were
placed in the RCRA impoundments, which had been cleared and
double-lined for this purpose. The contaminated water was
processed at the plant to recover any usable materials and the
soils were transferred to the BN RCRA-regulated facility in
Paradise, Montana to await treatment.
In October, 1985, the EPA, BN and Sliters signed an
Administrative Order on Consent (Docket No. CERCLA-VIII-85-07)
for a Remedial Investigation and Feasibility Study (RI/FS).
The purpose of the Remedial Investigation and Feasibility Study
was to determine the nature and extent of contamination at the
Site, to evaluate the impacts of contamination on public health
and the environment and to formulate alternatives for remedial
action. BN began conducting the work under EPA supervision in
the fall of 1985 and completed its field investigations in the
fall of 1988. Sliters provided access to their property for site
investigations. A Remedial Investigation/Feasibility Study
report, consisting of final Site Investigation and Exposure and
Endangerment reports and a public review draft Feasibility Study,
was submitted to EPA in the spring of 1989 (Remediation
Technologies, 1989). Correspondence between the EPA and BN
regarding the Remedial Investigation/Feasibility Study is
contained in the Administrative Record file.
The RCRA impoundments were filled in and covered with
pavement by BN in 1988 pursuant to a closure plan approved by the
MDHES. Subsequent to the closure of the RCRA impoundments, a
ground water monitoring well located adjacent to the impoundments
indicated that ground water was contaminated; therefore ground
water corrective action was required. BN submitted a proposal
for corrective action to the MDHES in February, 1989. In order
to ensure coordination of the RCRA and CERCLA facets of site
activities, the EPA has consulted with the MDHES and kept the
agency involved in all CERCLA activities.
In June 1988, the EPA published a notice of intent to remove
the Site from the proposed National Priorities List, because of
its status as a RCRA-regulated facility. The MDHES and various
community groups have made requests to the EPA that the Site be
retained on the proposed National Priorities List. As of the
date of this Record of Decision, the Site has not been removed
from the proposed list.
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0100634
III. Highlights of Community Participation
Section 113 (k)(2)(B)(i-v ) of CERCLA, 42 U.S.C. Part 9601,
sets forth the minimum requirements for public participation in
the CERCLA remedial action process. The EPA and MDHES have
maintained an active community relations program at the Site.
Fact sheets and periodic updates were prepared and public
meetings were conducted to keep Somers residents and other
interested parties informed about site activities. An
information repository was established at the Somers Central
School Library. In.May of 1988, the EPA and MDHES conducted
interviews of local and State officials and other interested
parties to determine the effectiveness of community relations
efforts and revised the Community Relations Plan.
Some of the concerns expressed by interested persons during
the Remedial Investigation/Feasibility Study related to possible
health effects caused by living near the Site, future
availability of the beach area for recreational use, and the
future availability of the tie plant property for development.
The Somers Water District expressed concerns about replacing
water mains which run across the tie plant property, and about
the possible effects of the Site on the municipal water supply.
The availability of Technical Assistance Grants for
citizen's groups was publicly noticed in several Montana
newspapers in the spring of 1988. In the fall of 1988, the EPA
received an application for a Technical Assistance Grant from the
Flathead Lake Protection Association. The EPA approved a
Technical Assistance Grant for this group in January, 1989. The
Association has participated in reviewing and interpreting of
Site technical reports and other documents.
The Remedial Investigation and Exposure and Endangerment
Assessment reports were released to the public for review in
April, 1989. On April 26, 1989, a notice of availability of
these reports was mailed to all persons on the Site mailing list.
An announcement of the availability of these documents was also
published in the Kalispell Daily Interlake newspaper on April 28,
1989.
The draft Feasibility Study and the Proposed Plan for the
Site were released to the public in May, 1989. A notice of
availability of the draft Feasibility Study and the Proposed Plan
was published in the Kalispell Daily Interlake on May 17 and May
21, 1989. A copy of the Proposed Plan was also mailed to all
persons on the Site mailing list.
The technical documents and plans, as well as other
information on the site, were made available to the public in the
administrative record file and information repository maintained
at the EPA Region VIII Montana Office Docket Room and at the
10
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0100635
Somers Central School Library. Both locations are open during
normal business hours.
A 30 day public comment period on the Remedial
Investigation/Feasibility Study reports and the Proposed Plan
began on May 18, 1989. Based on a request from the Flathead Lake
Protection Association, EPA extended the close of the comment
period to July 15, 1989. An announcement of the extension to the
comment period was mailed to all persons on the Site mailing list
and was published in the Kalispell Daily Interlake.
A public meeting was held on June 6, 1989, at the Somers
Central School. At this meeting, representatives from EPA
presented the proposed plan and EPA and MDHES representatives
ansv^red questions about the problems being addressed at the Site
and the remedial alternatives under consideration. BN
representatives were also available to answer questions. A
transcript of the meeting was produced and is contained in the
Administrative Record file. A second community meeting was
conducted on June 21, 1989, in Paradise, Montana, at the request
of local residents.
The EPA and the State of Montana received substantial public
comment in opposition to the EPA proposal for soil remediation
which involved transportation of contaminated soils from Somers
to the BN facility in Paradise, Montana for treatment. In a
letter of July 5, 1989, the MDHES requested that the EPA
reconsider its preference for this alternative. On July 14,
1989, the EPA extended the close of the comment period to August
3, 1989. An announcement of this extension was issued in the
form of a press release, was published in the Kalispell Daily
Interlake and was also mailed to all persons on the Site mailing
list. The announcement indicated that EPA had been asked to
reconsider its proposed plan and was extending the comment period
to allow further consideration of on-site biological soils
treatment. A second Somers public meeting was announced in the
same notice. The meeting was held on July 27, 1989.
A response to the comments received during the comment
period is included in the Responsiveness Summary, which is a part
of this Record of Decision (Attachment B).
IV. Scope and Role of Response Action Within Site Strategy
The problems at Somers have been addressed in stages under
different authorities. The first stage consisted of an emergency
cleanup of the swamp pond area conducted in 1985 by BN under the
oversight of the Superfund removal program. Although not a
Superfund activity, the second stage involved the closure and
capping of the two RCRA impoundments pursuant to State RCRA
authority. Stage two will also include corrective action for
ground water contamination from these units.
1 1
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01G0636
The remedial actions described in this Record of Decision
constitute a third stage of cleanup activities addressing the
remaining contaminants in soils, sediments and ground water, all
of which have been determined to pose a threat or potential
threat to human health and the environment as described in
Section VI of this Record of Decision. The response objectives
of remedial action are to control and remediate contaminated soil
through excavation and treatment; to minimize, eliminate and
prevent current or future exposure of humans and other receptors
to contaminated soils; to reduce contaminant migration to ground
water; and to clean up contaminated ground water and prevent
adverse impacts on surface water. The remedy selection process
in this Record of Decision treats both soil/sediment and ground
water components as a single response action. This action is
anticipated to be the final response action for this site.
V. Site Characteristics
The primary source of site contamination was process
wastewater from the treatment of wood products with creosote and
zinc chloride preservative solutions. Process wastewater from
creosote wood treating operations is listed as a RCRA hazardous
waste under the category K001. Soil and debris contaminated by
such wastewater is also considered K001 waste. As discussed
previously, BN disposed of process wastewater at the Site in the
CERCLA lagoon which overflowed via a ditch directly into Flathead
Lake. A swamp pond which formed along the ditch also accumulated
waste materials. Soils contaminated with creosote constituents
and/or zinc have been found to be concentrated in the CERCLA
lagoon, along the discharge ditch and in the former swamp pond
and beach area. Other areas with contaminated soils include the
drippage area along the railroad tracks where treated ties were
removed from the retort (the "drip track"), and in the treated
tie storage area in the slough. Figure 4 shows the approximate
extent of known soil contamination. Ground water is contaminated
with creosote in the vicinity of the CERCLA lagoon and the former
swamp pond (Figure 5).
The following discussion will concentrate on the types of
contaminants, affected media and known or potential routes of
human and environmental exposure.
Contaminants
Initial samples of ground water, soils, and surface water
were subjected to analysis for CERCLA Hazardous Substance List
(HSL) compounds in order to develop a parameter list for future
analyses. Creosote constituents constituted the majority of
organic compounds detected in samples taken from the CERCLA
lagoon area. Zinc was also found at elevated concentrations in
this area. Creosote constituents and zinc were therefore
12
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Approxlmal* Extent
Soil Contamination
Source: Remediation Technologies (1989), Volume 1
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/I4INIAO |*n|
Source: Remediation Technologies (1989), Vol. 1.
tICIMO
\ Will lOCAIIOH
; GroundwcMr Conurrtntkon
Inferred Eit«nt of
Iroundwalcr Contamination
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0100639
selected for ongoing analysis at the site and are discussed in
more detail below. Benzene was detected in one ground water
sample, but was not found in other HSL samples and was not
selected for further analyses. A number of inorganic compounds,
in addition to zinc, were identified in the HSL samples and were
selected for further analyses. These parameters are listed below
under "Other Compounds." Other than zinc, inorganic constituents
were not generally found to be present at elevated concentrations
at the site.
Creosote: Creosote is a complex mixture of hundreds of
identifiable constituents produced by the high temperature
carbonization of coal. It consists mainly of liquid and solid
polynuclear aromatic hydrocarbons (PAHs), although some tar acids
(such as phenols and cresols), tar bases (such as pyridenes and
acridine), and nitrogen bearing heterocyclic bases (such as
quinoline and benzocarbazole) are also present. The composition
and physical properties of creosote vary depending on the coal
distillation process.
The PAHs compose the majority of the organic compounds in
creosote and are the major constituents of concern at the BN-
Somers site. Sixteen individual PAH compounds are listed as
priority pollutants by the EPA. The physical and toxicological
characteristics of the PAHs vary with relative molecular weight.
Eight of the priority pollutant PAHs have relatively low
molecular weights, are fairly soluble in water and have low
organic carbon partition coefficients. The other eight PAHs tend
to adsorb more strongly to solids when released into the
environment, particularly if the organic carbon content is high.
The water solubilities of the PAHs range from 3.93 ppm for
Acenaphthalene to 7.00 x 10~4 ppm for Benzo(g,h,i)perylene. PAH
compounds are known to be biodegradable; low molecular weight
PAHs tend to degrade more quickly than high molecular weight
PAHs. PAH compounds are also considered to be semi-volatile.
The lower molecular weight compounds are typically more volatile
than the higher molecular weight compounds. Vapor pressures
among PAHs range between 2.90 x 10~^ torr for Acenaphthalene and
1.0 x 10~10 torr for Indeno(1,2,3-c,d)pyrene,
Dibenzo(a,h)anthracene, and Benzo(g,h,i )perylene. Because of
their greater solubility and volatility, the low molecular weight
compounds are more mobile in the environment.
The high molecular weight PAHs are considered to be
carcinogenic. Other creosote constituents considered to be
carcinogenic include heterocyclic nitrogen bases and aromatic
amines. Several of the low molecular weight PAHs are considered
to be mutagens or co-carcinogens; others are carcinogenic
inhibitors. The most significant known adverse health effect
following exposure to noncarcinogenic PAHs is hemolysis.
No EPA drinking water standards exist for PAH compounds.
13
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0100640
However, EPA has published ambient Water Quality Criteria for
three PAH compounds to protect aquatic life and human health
(Table 1).
Zinc: Zinc is a metallic element which may form compounds with
both inorganic and organic ligands. It is toxic only at very
high concentrations and is, in fact, an essential trace element
for humans and domestic animals. No human health based standards
or criteria exist for the consumption of zinc in water supplies,
although a secondary drinking water standard of 5,000 ug/1 was
established for taste and odor. Zinc is not considered to be
carcinogenic.
Zinc is very soluble in water. Zinc chloride has a
solubility of 4320 g/1. In an aquatic environment concentrations
of zinc in sediments exceed concentrations in ambient water.
This effect is modified by pH, salinity, water hardness, and
temperature. The EPA has published ambient Water Quality
Criteria to protect freshwater aquatic life from adverse
concentrations of zinc (Table 1). Contrary to the apparent
relative resistance of humans to high zinc concentrations, many
forms of aquatic life have a very low tolerance to zinc,
reflected by the low ambient Water Quality Criteria. These
concentrations decrease with decreasing water hardness.
Other Compounds: Benzene is a carcinogenic volatile organic
compound with a solubility in water of 1,850 mg/1 at 25°C. The
EPA has published both Water Quality Criteria and Maximum
Contaminant Levels for benzene (Table 1). Volatile compounds do
not tend to adsorb easily onto soils and tend to be very mobile
in the environment. Benzene was detected at 67 ug/1 in only one
ground water sample from the CERCLA lagoon. It was not detected
in other ground water or soil samples. Investigators did not
analyze further for benzene during the Site investigations.
Several non-chlorinated phenolic compounds were also found
at the BN-Somers site. Phenolic compounds tend to be mobile in
ground water due to a relatively high solubility (on the order of
1.70 x 10"1"1 to 9.30 x 10+4 mg/1). These compounds are also among
the more volatile compounds, with a vapor pressure on the order
of 3.41 x 10~1 to 6.00 x 10~2 torr. Phenols are considered to be
noncarcinogenic but cause various systemic effects. Water
Quality Criteria have been published for phenol (Table 1).
Arsenic, selenium, lead, chromium, copper, barium,
beryllium, mercury, nickel, and thallium were also detected in
the HSL sampling and were selected as constituents for analysis
in further sampling at the site. Safe Drinking Water Act Maximum
Contaminant Levels and ambient Water Quality Criteria have been
established for these compounds; these are provided in Table 1.
Chromium, arsenates and copper have been used in the wood
treating process at other wood treating plants, however, arsenic
14
-------
TABLE 1
WATER QUALITY CRITERIA AND STANDARDS FOR WOOD PRESERVATIVES USED AT SCHERS
.:enaphthene
Itioranthene
i..|)hthalene
Aquatic
Acute
1,700
3,980
2,300
F.PA Ambient
Life
Chronic
520
620
Water ftialltv Criteria ( no/1 ) Drlnlrlnp Havlmim
Water (Vmtaminant
Human Health ftt«rvlfjrH«j lj>uel Poffl
Fnrirl Water & Frrvl ("g/1} (llg/1 )
20 (taste & odor)
54 42
^rclnogenlc PAH***
6 10'3 Risk Level
@ 10~6 Risk Level
6 10-7 Risk Level
/l her Constituents
r.ciizene 5,300
6 10"5 Risk Level
6 10~6 Risk Level
@ 10~7 Risk Level
rhenol 10,200 2,560
usenlc
V 850 48
III 360 190
0-311
0-0311
0-00311
400
40
4
0 -018
0-028
0.0028
0.00028
6.6
0.66
0.066
3,500
0.0022
...irlum
1,000
50*
1.000
1,500
C
C
O
-------
TABLE 1, CONTINUED
EPA Amhtpnt Water ftialttv Crltprla f iio/l 1 Hrtnlclno
, erylllum
.hromium
VI
III
-lopper
Lead
Mercury
Nickel
Selenium
Thallium
Zinc
* Maximum Contaminant Level
Aquat ic
Arntp
130
16*
1,700*
18*
82*
2.4
1,400*
260
1,400
120*
Life
Chronic
5-3
11*
210* 3,
12*
3.2*
0-012
160*
35
40
110*
HaLex
Human Health Standard
Fnnrf WAtgr f. FonH (ug/1^
0-12 0.0068
50 50
433,000 170,000
1,000 100 (taste & odor)
50 50
0.15 0.14 2
100 13-4
10 10
48 13
5,000 5,000**
Mavlmnn
(Vmtamlnant
I p\;*>l (V^i]
LufcOl
120
1,200
1,300
20
3
45
»* Secondary Drinking Water Standard
.**Carclnogenic PAH values are
' Hardness-dependent, 100 mg/L
for individual compounds
CaC03
or for combinations of these compounds-
Sources:
U.S EPA (1986a) Superfund Public Health Evaluation Manual, EPA 5401-1/86/060, OERR.
U.S. EPA (1986b) Quality Criteria for Water, EPA 440/5-86-001 (51 Federal Register 43665).
O
CD
CTi
4-*
D
-------
01006«3
and copper were not reportedly used at the Somers Site. Other
than one subsurface soil sample which contained elevated arsenic,
possibly due to laboratory error, no samples showed inorganics
(other than zinc) at concentrations which significantly exceeded
background.
Affected Media
Soils in the Somers area are identified as silty clay loams,
consisting primarily of silts and fine sands. Most of the soils
in the area were deposited by glacial or alluvial processes.
Glacial soils are heterogeneous, commonly containing clayey and
unsorted deposits. Regional soil thicknesses range from zero to
over 500 feet. Subsurface conditions in the vicinity of the
former tie plant vary with depth. The plant yard property is
covered with a veneer of 0.5 to 10 feet of man-made gravel fill.
Underlying the fill are discontinuous layers of silty sand and
sandy silt underlain by a thick silt unit containing interbedded
silty sands and clays.
The bedrock surface in the Somers area is very irregular.
Bedrock outcrops are present to the west of the former RCRA
impoundments and to the west of the discharge ditch and swamp
areas. Away from the outcrop, borings to a depth of 100 feet
failed to encounter bedrock.
Three aquifers have been identified at Somers. The
uppermost unit is a water table aquifer located in alluvium.
This unit yields small volumes of water to domestic and stock
wells. Well encrustation from iron bacteria, low yields, and
marginal water quality have prevented significant use of this
aquifer in the Somers area (Noble 1986). Five residences in
Somers, upgradient from the tie plant, have water supply wells
completed in this aquifer; none are used for drinking water. The
water table aquifer discharges to Flathead Lake during periods of
low lake level and is recharged by the lake during summer months
when lake levels are high.
Underlying the water table aquifer, and separated from it by
low-permeability silty/clay materials, is an artesian aquifer.
The artesian aquifer was encountered in two wells at depths of 60
and 90 feet at the Site. This aquifer consists of a number of
sand and gravel deposits separated by discontinuous beds of fine-
grained material. No residential wells in Somers are completed
in this unit.
Underlying the artesian aquifer is the bedrock aquifer. It
is present within the secondary structural features such as
joints and fractures. One residential well and the Somers School
well are completed in bedrock. Two municipal bedrock wells are
proposed for the municipal supply and are anticipated to be
constructed in 1989.
15
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01006-54
Affected Soils and Sediments: The majority of contaminated soils
at the BN-Somers site have been found beneath and adjacent to the
CERCLA lagoon, along the former discharge ditch, along the drip
track and near the former swamp pond. The heaviest contamination
in the form of oil/soil mixtures is confined to the upper few
feet of the CERCLA lagoon and the surface of the drip track.
Other areas of contamination have been found in the slough where
treated ties were stored, in the swamp area and in beach
sediments below the high water line. The contamination in the
beach area is believed to be .either a remnant of discharges from
the ditch or from contaminated ground water originating in the
swamp area. The primary contaminants of concern in soils and
sediments are PAHs, but zinc in the slough is also of concern
because of potential adverse impacts to aquatic life and
waterfowl.
The highest concentration of PAH contaminants was found in
the 15,600 square foot CERCLA lagoon. PAHs have been detected in
samples from the CERCLA lagoon at concentrations from over
500,000 mg/kg at the surface to 369 mg/kg at a depth of 25 feet.
Low molecular weight compounds predominate. The maximum zinc
concentration in this area is 4,400 mg/kg. The maximum depth of
high molecular weight PAH contamination is approximately 30 feet.
Test pits downgradient from the CERCLA lagoon show that
visible contamination typically begins at a depth of 6 to 10
feet. This is the high water table mark. Contaminants have
apparently been carried in ground water to this area from the
CERCLA lagoon. The maximum total PAH concentration detected in
these test pits was 3,300 mg/kg in the saturated zone. Surface
soil samples show a maximum of 28 mg/kg total PAH in a sample
collected immediately adjacent to the CERCLA lagoon. The maximum
zinc concentration detected in these test pits was 3,770 mg/kg
immediately adjacent to the CERCLA lagoon. Based on well
borings, the maximum depth of contamination downgradient from the
CERCLA lagoon is approximately 30 feet immediately adjacent to
the lagoon. The contaminated area bounded by these test pits and
wells is approximately semi-circular in shape with an area of
about 48,100 square feet.
Soils in the drainage ditch are contaminated to a depth of
about one foot and a width of less than five feet. The length of
the ditch is approximately 1,200 feet. Maximum total PAH
concentrations measured in the ditch near the swamp area after
the 1985 Emergency Removal were 7,228 mg/kg. Average
concentrations were 3,234 mg/kg.
The former swamp pond covered an area of about 29,000 square
feet. Because of migration of contaminants from the pond, an
area of 60,500 square feet was excavated in 1985. The excavated
area was covered with clean gravels. Maximum residual PAH
i 6
-------
01006*5
concentrations in the swamp area, taken after the removal, were
3,281 mg/kg. The average residual concentration was calculated
to be 1,280 mg/kg. The water table in this area fluctuates
seasonally, but is usually at or just below the ground surface.
All residual contamination is therefore typically below the water
table. Based on borings in this area, the maximum depth of
contamination is 20 feet.
Beach borings show that sediment contamination downgradient
from the former swamp pond begins at a depth of 2 feet and
extends to a depth of over 8 feet. Contaminants have been found
in an area covering-approximately 22,500 square feet. The
contaminated beach sediments are below the high water level of
Flathead Lake. The maximum total PAH concentration detected in
this area exceeded 400 mg/kg. The maximum zinc concentration
detected was 45 mg/kg. Contamination is not continuous, but
appears to be limited to decayed root channels.
The drip tracks occupy an area of approximately 42,000
square feet. Visible evidence of contamination in soil is
limited to the upper 2.8 feet. No PAH contamination was detected
in this area. This may be because samples were restricted to an
area adjacent to the track bed itself. Zinc was detected at a
maximum concentration of 12,000 mg/kg.
A portion of the slough adjacent to the tie plant is
contaminated with PAH and zinc. The maximum concentration of PAH
detected was 342 mg/kg. The maximum concentration of zinc found
was 8,570 mg/kg. The area of contamination covers approximately
2,500 square feet; the maximum depth of contamination is about 4
feet.
Historical records indicate that contaminated water may have
periodically been released into the retort building basement. It
is therefore presumed that the soils in this area are also
contaminated.
Affected Ground Water and Drinking Water: Contamination has been
identified in the water table aquifer in two areas: in and
downgradient from the CERCLA lagoon, and in the swamp pond area.
The primary contaminants of concern in the ground water are PAH
compounds and phenols. Certain metals have been detected above
background, and sometimes above Maximum Contaminant Levels,
however, the high suspended solid concentrations in these
unfiltered samples appear to have caused the elevated
concentrations of metals. Filtered samples taken immediately
downgradient from the CERCLA lagoon did not exceed Maximum
Contaminant Levels for any parameter. Samples taken in the
immediate vicinity of the swamp pond also were within Maximum
Contaminant Levels for inorganics.
Monitoring wells completed in the CERCLA lagoon itself
17
-------
0100616
contain visible evidence of oil contamination and concentrations
of up to 4,000,000 ug/1 total PAH. Monitoring wells located
immediately downgradient from the CERCLA lagoon contained from 67
to 3,292 ug/1 total PAH (all low molecular weight compounds) and
from 785 to 206,400 ug/1 total phenolics. The contaminant plume
emanating from the CERCLA lagoon has migrated between 400 and 600
feet downgradient.
Monitoring wells completed in the former swamp pond area
have produced oil in the purge water and samples containing up to
18,280 ug/1 total PAH (all low molecular weight compounds).
The Somers water supply is currently drawn from Flathead
Lake, at an intake located about 2,000 feet from the swamp pond
area. Samples of the Somers drinking water supply occasionally
showed high molecular weight PAH compounds. The cancer risk
level associated with detected concentrations is less than 1 x
10~5. Inorganic concentrations were all within Maximum
Contaminant Levels.
Routes of Migration
The potential routes of migration from soil and sediment
contaminant sources at the Site are primarily to air and water.
The main potential route of migration from ground water is to
surface water.
Exposed contaminated soils may volatilize or produce
particulate emissions to air. This is of particular concern in
the vicinity of the CERCLA lagoon which is unvegetated and
located adjacent to a residential area. Both wind-borne
particulates and vapor emissions can occur from this area. Other
source areas such as the drainage ditch and slough, are vegetated
and would be less likely to emit contaminants to air. The swamp
and beach area soils and sediments are covered with clean fill
and sand, respectively, which would also prevent air emissions.
Because of the proximity of the swamp pond to Flathead Lake
and the presence of PAH contaminants in ground water, it must be
assumed that contaminants are entering Flathead Lake. However,
samples taken of lake water offshore of the swamp pond area
showed very low concentrations of some low molecular weight PAHs.
This may indicate a small but measurable impact. However, the
concentrations detected were many orders of magnitude below Water
Quality Criteria (two compounds were detected for which such
criteria have been established). Inorganic analyses were all
within Maximum Contaminant Levels and Water Quality Criteria.
VI. Summary of Site Risks
A baseline risk assessment was conducted at the Site by BN
under EPA oversight. Based on this assessment, the EPA
18
-------
01006J7
determined that contaminated soils and ground water pose the
greatest risk to human health and the environment. The EPA has
not found evidence of acute risks to human health posed by site
contaminants. Field observations of fish and waterfowl have not
revealed any impacts associated with acute exposures. The EPA
has concluded that the risks present at the Site are those which
result from subchronic or chronic exposure durations to the
compounds of concern. These risks are discussed below.
Indicator Compounds
Indicator chemicals are used to identify the highest risk
chemicals at a site so that the risk assessment is focused on the
chemicals of greatest concern. The EPA has selected various
indicator compounds based on prevalence, mobility, persistence
and/or toxicity at the Site. The following groups of compounds
were selected as indicator chemicals for risk assessment: 16
different compounds identified as polynuclear aromatic
hydrocarbons (PAHs), phenols, and zinc.
Samples were not routinely analyzed for volatile organic
compounds and nitrogen-bearing heterocyclic compounds, although
the 1985 and 1986 source evaluation at the Site included analyses
for benzene. As discussed previously, one sample of ground water
from the CERCLA lagoon was found to contain benzene, however a
soil sample from this area failed to verify the presence of
benzene. The potential significance of benzene as a ground water
contaminant was considered in the risk assessment. Additional
sampling and analysis for benzene and other volatile constituents
will be conducted during remedial design to verify these results.
Samples were routinely analyzed for a range of inorganic
constituents. Of these, only zinc was found to be present at
levels higher than background concentrations or accepted soil
concentration guidelines (Remediation Technologies, 1989). High
sediment content in some monitoring wells appears to have been
responsible for some water samples exceeding Maximum Contaminant
Levels (Remediation Technologies, 1989). Filtered ground water
samples did not exceed Maximum Contaminant Levels for any
parameter.
Toxicity Assessment
PAH compounds can be divided into two categories based on
molecular weight. High molecular weight PAHs tend to be
carcinogenic. Low molecular weight PAHs tend to be
noncarcinogenic, although they may be cancer initiators or
promoters. Some low molecular weight PAHs, such as naphthalene,
are cancer inhibitors.
A number of conservative assumptions were made in conducting
the risk assessment for the BN-Somers site. Benzo(a)pyrene is
19
-------
0100618
often used in estimating the risks associated with other
carcinogenic PAH compounds. Benzo(a)pyrene is one of the most
potent of the carcinogenic PAHs. The EPA's published potency
factor for benzo(a)pyrene was used in evaluating the risks to
humans associated with all carcinogenic PAHs.
For noncarcinogenic PAH compounds, the acceptable daily
intake for chronic exposure (AIC) or reference dose (RfD) was
used to evaluate the potential for systemic human health effects.
The AIC or RfD numbers are threshold values below which no health
effects are expected. Frequently, these values are established
based on animal experiments. These values have safety factors
built in to account for uncertainties in their development.
Typically, these safety factors include a factor of 10 for the
expected differences in response between humans and animals,
another factor of 10 for the variability within a population, and
a third factor of 10 for a limited database. The RfD/AIC and
carcinogenic potency factors used in the risk assessment are
provided in Table 2.
Available information on the toxicity of many of the
indicator chemicals is limited and tends to be based on animal
studies. In general, PAH compounds may cause adverse health
effects from ingestion, inhalation, and dermal absorption. The
effects of exposure to high concentrations of these compounds may
be manifest in problems such as decreases in body weight, toxic
effects in various organs such as the liver and kidney, and skin
or eye irritation. Even at low concentrations, high molecular
weight PAH compounds, such as Benzo(a)pyrene, are known to cause
cancer in laboratory animals. Some of the lower molecular weight
PAH compounds may be cancer initiators or co-carcinogens (cause
cancer in the presence of another compound). The high molecular
weight PAH compounds may have both carcinogenic and systemic
effects. Phenolic compounds have been shown to cause skin
irritation and kidney or liver pathology. Zinc is a necessary
nutrient for humans; however, in high doses it has been shown to
cause pulmonary edema, jaundice, gastrointestinal problems and
respiratory tract infections.
Exposure Routes
The BN-Somers tie plant has been closed since 1986. The
Site is surrounded by a residential community and the property
could possibly be used for other commercial or residential
development in the future. For these reasons, the Risk
Assessment for the Site used a residential exposure scenario.
The. following exposure pathways were found to be the most
significant:
Existing exposure routes:
o Direct contact/ingestion of surficial soils in the
20
-------
TABLE 2
TOKICITY VALUES USED FOR RISK CHARACTERIZATION
RfD/AlC
Pnr.->in<»t<»r
PAHs:
Naphthalene
Acenaphthalene
Acenaphthene
Kluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Benzo(a)anthracene
Chrysene
Benzo(b)fluoranthene
Benzo(k)fluorant hene
benzo(a)pyrene
lndeno(1,2,3-c,d)pyrene
D1benzo(a,h)ant hracene
Benzo(gih,1)pery1ene
Phenol
Oral
0.05
.04
Cancer Potency Factor
\-l
Oral
to 0.005
.03
.20
.07*
.07*
.07*
.07*
.06
-07*
.07*
-07*
.07*
.07*
.07*
.07*
.07*
11-50
11.50
11.50
11.50
11.50
11.50
11.50
11.50
TnhftlaHrm
6-11
6-11
6-11
6-11
6.11
6.11
6-11
6-11
Zinc -21
•Value assumed equal to average AIC for other noncarclnogenlc PAH-
for all values provided In Kemedlallon Technologies (1989) Vol. 2.
O
o
en
-------
0100650
vicinity of current residences;
o Direct contact/ingestion of surficial soils on the tie-
plant, property; and
o Inhalation of volatile compounds and fugitive dusts
from the CERCLA lagoon and other contaminated areas.
Potential exposure routes:
o Ingestion of ground water from wells completed
downgradient from the CERCLA lagoon; and
o Direct contact/ingestion of soils after development of
the tie plant property.
Current or potential environmental exposure routes:
o Direct contact/ingestion of soils and sediments or
water by wildlife, fish and other aquatic life; and
o Consumption of environmental contaminants via the food
chain.
The following exposure routes were evaluated but were not
found to presently pose a significant risk:
o Ingestion of drinking water from the municipal supply
drawn from Flathead Lake;
o Ingestion of fish from Flathead Lake;
o Contact with lake water and beach sediments;
o Ingestion of vegetables from local gardens;
o Ingestion of soils and vegetation by grazing animals;
and
o Ingestion of beef from grazing cattle.
Eight out of ten samples taken from the Somers municipal
drinking water supply were within the 0.0028 ug/1 EPA Water
Quality Criterion for carcinogenic PAH compounds. This
concentration equates to the 1 x 10~^ risk level. The remaining
two samples were within the 0.028 ug/1 criterion (a risk of 1 x
10~5). There is no indication that Water Quality Criteria are
exceeded in Flathead Lake. Low concentrations (on the order of a
few nanograms per liter) of non-carcinogenic PAH compounds have
been detected in lake water. These concentrations are typical of
surface water bodies in the United States. Consumption of fish
from Flathead Lake poses a negligible carcinogenic risk.
Contaminated beach sediments in Flathead Lake are covered by
a few feet of clean sand. The beach is exposed only when lake
levels are low. The lake levels are high during the summer
months when swimming or playing at the beach is most likely to
occur.
Although plants may incorporate some PAHs into their
tissues, biomagnification levels are very low. Surface soil PAH
21
-------
010065
concentrations outside of demonstrated source areas are also very
low. Water available to residents for watering gardens adjacent
to source areas comes from the municipal supply. Consumption of
garden vegetables therefore does not pose an unacceptable risk to
local residents.
A portion of the BN-Somers study area, adjacent to the
discharge ditch, was used for grazing cattle in the past.
Estimates of the uptake of PAHs by cattle, based on samples
collected from the ditch, indicated that exposure would not
result in a toxic effect. Furthermore, evidence in the
literature indicates that PAHs are metabolized and excreted by
vertebrate organisms, and that PAHs do not tend to accumulate in
fatty tissues. Therefore, risk through human consumption of
cattle that might graze in this area is not a concern.
The investigations also evaluated the possible effects of
exposure through ingestion of drinking water from the proposed
municipal wells. There is no evidence to suggest contamination
of the bedrock aquifer or the overlying artesian aquifer. The
presence of an aquitard beneath the contaminated water table
aquifer will inhibit the migration of contaminants into the
underlying artesian system. The proposed well locations are
about 900 feet from the contaminated portions of the Site.
Although it is considered unlikely, drawdown induced by the
municipal wells could conceivably result in the expansion of
ground water contaminant plumes and possibly some movement of
contaminated water from the water table aquifer into the artesian
or bedrock aquifer system. A pump test for the proposed wells
has been designed to evaluate this possibility. The test will be
conducted as soon as the wells are completed.
The following assumptions were used to evaluate risks posed
by the exposure pathways determined to be of concern.
Soil direct contact/inqestion exposure;
o Children from 1 to 6 years old ingest 200 mg of soil
per day. Older children and adults ingest 100 mg/day
(USEPA 1989);
o Exposures are limited to the 7 months each year when
the average monthly temperature is above freezing. A
separate calculation is presented for children 1 to 6
years old to evaluate systemic effects. This
calculation assumes daily exposure for a continuous 90-
day period when the ground is not frozen;
o Children visit the tie plant property 30 times per year
from the ages of 5 to 12 years;
o A 20 to 60% matrix effect is used to estimate the
availability of PAH compounds bound to soils to the
gastrointestinal tract (Umbreit et al 1986). (Ma-rix
effects refer to the difference in the bioavailability
22
-------
0100632
of a compound from soils compared to the
bioavailability of the chemical itself).
o No biodegradation is assumed. Monitored concentrations
are assumed to be constant for the next 70 years.
Inhalation exposure:
o An individual inhales 20 m3 of air per day (USEPA
1986);
o Exposure occurs for the 7 months a year when the
average monthly temperature is above freezing;
o An individual spends all day, every day at his/her
residence over an average 70 year lifetime (USEPA
1986);
o Fugitive dust concentrations were estimated by an EPA-
approved model contained in "Rapid Assessment of
Exposures to Particulate Emissions from Surface
Contamination Sites" (Cowherd et al, 1984);
o Exposure point concentrations 50 feet from the sources
were estimated by the Near Field Box Model (Pasquill
1975, and Horst 1979) to evaluate risks to residents
living adjacent to the tie plant; and
o Exposures to volatile emissions from the CERCLA lagoon
were estimated using the Industrial Source Complex
Short-Term Dispersion Model (Bowers et. al 1979).
Potential ground water ingestion exposure:
o Individuals drink 1 liter of water per day as children
and 2 liters per day as adults (USEPA 1986);
o Potential subchronic/chronic exposures are calculated
for children because of their smaller body weight; and
o The average concentration of contaminants in water
remains constant over time.
Risk Characterization
In calculating risks from exposure to non-carcinogens, the
hazard index is used. The hazard index approach assesses the
overall potential for noncarcinogenic effects posed by multiple
chemicals by assuming that multiple sub-threshold exposures could
result in an adverse effect. The magnitude of the adverse effect
is assumed to be proportional to the sum of the ratios of the
sub-threshold exposures to acceptable exposures. Any single
chemical with an exposure level greater than the reference level
will cause the hazard index to exceed "1." Ratios in excess of
"1" are considered to have the potential for a non-carcinogenic
systemic health risk.
Risk estimates for carcinogens are expressed as the lifetime
probability of cancer associated with a given dose. The EPA
considers an acceptable risk from carcinogenic compounds to fall
23
-------
0100653
within a range of one excess cancer per ten thousand exposed
individuals (a risk of 1 x 10"^) to one excess cancer in ten
million individuals (a risk of 1 x 10~7), with a goal of one in a
million (a risk of 1 x 10~6). The one in a million goal may be
modified if technological constraints prevent achieving this
level. Risk levels calculated for the various exposure routes
are described below:
Existing Exposures: Incidental ingestion of soils was found
to be the primary contributor of risks to human health. Under
the current residential exposure, assuming no contact with site
source areas, the carcinogenic risk level was estimated to be
1.14 in one hundred thousand (1.14 x 10~5). The hazard index for
this route is less than one for noncarcinogenic systemic effects.
For local children who also visit the CERCLA lagoon periodically,
the additional carcinogenic risk is 8.65 in a million (8.65 x 10"
6). However, the hazard index for the CERCLA lagoon exceeds one,
primarily due to the presence of naphthalene. Risks through
exposure to carcinogenic compounds in the CERCLA lagoon and
certain areas of the drainage ditch and slough exceed the one in
ten thousand (1 x 10~4) risk level for soils. It is assumed that
drip track soils also exceed the one in ten thousand risk level,
due to obvious heavy contamination.
No direct measurements were made of compounds in air after
the tie plant was closed. Risk estimates for inhalation of
indicator compounds were therefore determined by modeling the
concentrations of contaminants which may be released from a
source area. The risk from this exposure route is primarily due
to naphthalene originating from the CERCLA lagoon. By estimating
the exposure point concentrations through modeling, the hazard
index exceeds one by this pathway. However, there is almost no
information on the health effects of low doses of naphthalene in
air. Also, the model used to determine the concentrations of
volatiles from the lagoon provides unrealistically high
concentrations due to an assumption in the model that the air
above the source is completely saturated with each compound of
interest. Models which accurately calculate the emissions of
volatiles from contaminated soils have not been developed. The
carcinogenic risk level is approximately seven in one-million (7
x 10~6), primarily from exposure to fugitive dust.
Potential human exposures: The most significant future risk
is due to the possibility of installation of drinking water wells
in the shallow water table aquifer downgradient from the CERCLA
lagoon. No carcinogenic compounds were detected in this area,
but the assumption was made that benzene (a carcinogen) may be
present because it was detected in one ground water sample from
the CERCLA lagoon. Although benzene was not routinely analyzed (
for .at the Site, the concentration found in the CERCLA lagoon
sample was used to calculate the risk due to ingestion of ground
water in this area. The estimated carcinogenic risk was
24
-------
0100654
determined to be slightly greater than one in ten thousand (1 x
10~4). The hazard index for consumption of ground water in this
area exceeds one due to high concentrations of naphthalene and
phenolic compounds. In addition, the proposed Somers municipal
wells, although planned for completion in bedrock, could
conceivably draw-down the aquifer to such an extent that the
water table aquifer in the vicinity of the contaminated areas
begins to impact the quality of the bedrock aquifer. The pump
test of the proposed wells will be designed to evaluate this
possibility.
Risks through direct contact with soils were considered
assuming that the tie plant is developed for residential use.
These risks were determined to be essentially the same as for
current residential use, assuming that residences are not placed
in known source areas. Future excavation in the area
downgradient from the CERCLA lagoon or in the swamp pond could
open additional pathways for exposure, however, local ordinance
currently prohibits excavation in these areas due to their
location in the floodplain. Construction is unlikely in the '
swamp area because the water table is at ground surface at
certain times of the year. Beach erosion could conceivably
uncover contaminated sediments in Flathead Lake and make them
available for direct contact during low lake levels.
Environmental exposures: Routes of environmental concern
primarily include exposure of wildlife to direct contact with
contaminated sediments in the slough and ingestion of
environmental contaminants via the food chain. Also of concern
is the potential for erosion to uncover contaminated beach
sediments, allowing fish and other aquatic life in Flathead Lake
to be exposed by direct contact or by ingestion of contaminants.
Continued migration of contaminated ground water into the lake
could also lead to detrimental impacts on water quality and
aquatic ecology.
The potential for plants to concentrate and store compounds
of interest is low because both zinc and PAH tend to bind to
sediments, rather than water, and because plants metabolize PAHs.
In general, biomagnification levels are low. However, sediments
from certain parts of the slough adjacent to the tie plant were
found to contain very high concentrations of zinc and PAH. Zinc
concentrations were also very high in slough water. The
concentrations detected may have the effect of limiting the
reproduction or species composition of the benthic fauna.
An assessment was made to determine whether any adverse
effects were manifest on waterfowl which inhabit the slough.
Observations of waterfowl over a 3.5 month period did not reveal
any physical or behavioral abnormalities. Analysis of waterfowl
tissue for zinc indicated that concentrations were normal and
consistent with concentrations measured in waterfowl from a
25
-------
010063,
nearby control, slough.
Although no evidence of significant adverse effects to
Flathead Lake was found through site sampling, the presence of
contaminants in ground water, in the swamp pond area and in
subsurface beach sediments indicate that the Site is affecting
the local environment. This will tend to continue until the site
is remediated.
VII. Description of Alternatives
The following discussion provides a description of the
alternatives considered during the detailed analysis of the BN-
Somers Feasibility Study (FS). The alternatives are numbered to
correspond to the numbers in the FS report, which presents the
alternatives in more detail. The remedial action costs and time
frames are estimates which will be refined during remedial
design. Although soil and ground water alternatives are
presented separately, the remedy selection process in this Record
of Decision treats both soil/sediment and ground water components
as a single response action.
Alternatives for Contaminated Soils
Table 3 lists the alternatives considered in the detailed
analysis for soil remediation. The alternatives are classified
by treatment, containment and institutional control components.
Alternative 1; No Action. This alternative does not involve
treatment or containment of contaminants, but does include
erecting fences and posting warning signs in contaminated areas
and instituting controls to prevent development of the Site. In
addition, potential pathways of contaminant release from the Site
would be monitored and provisions for appropriate action would be
made in the event of a release that could cause an unacceptable
risk.
Fencing and deed restrictions would be used to prevent
access to contaminated areas. Fenced areas would include the
CERCLA lagoon, the retort building, and the drip track.
Restrictions would be placed in the deed to properties including
the areas of the CERCLA lagoon, drip track, retort building,
discharge ditch, former swamp pond and a portion of the slough.
Ground water monitoring would be implemented in conjunction with
the ground water no action alternative discussed later. This
alternative could be implemented in a few months to half a year.
Fencing and institutional controls would not be completely
reliable due to uncertainties about the maintenance of these
controls. Since contaminated soils would be left in place,
contaminants would continue to seep into ground water and ground
water contamination would continue to affect Flathead Lake.
26
-------
TABLE 3
SOIL ALTERNATIVES
KhMEDTAl. OPTION
BIOLOGICAL SOILS
TREATMENT
THERMAL SOILS
TREATMENT
CHEMICAL SOILS
TREATMENT
CONTAINMENT
INSTITUTIONAL
CONTROLS
ALT 1
No Action
71 TYPE
PROCESS OPTION
Land Treatment
Incineration
Stabilization
On-Slte Disposal
Capping
Fencing X
Deed Restrictions X
Zoning Restrictions X
Monitoring X
ALT 3
a.b.d
Excavate &
Biologically
Treat On-Slte
X
X
X
X
X
X
X
ALT 3
c
Excavate &
Land Treat
Off-Site
X
X
X
X
X
X
X
ALT 5
Excavate &
Stabilize/
On-Slte
Disposal
X
X
X
X
X
X
X
ALT 7
a,b
Excavate &
Incinerate/
On-Slte
X
X
X
X
X
X
X
X
o
t—'
o
CD
CD
-------
0100657
Applicable or Relevant and Appropriate Requirements (ARARs) are
not met by this alternative. Capital cost estimates, based on
fencing, signs, administrative costs and legal costs, would be
$238,000. Annual costs would be $2,500. The total present worth
cost would be $262,000.
Alternative 3a: Partial Excavation with On-Site Biological
Treatment of Soils. This alternative would involve excavating
11,100 cubic yards of contaminated soils in the CERCLA lagoon,
drip track, drainage ditch and retort building areas. Some
contaminated soils would remain below the water table in the
CERCLA lagoon. Soils in these areas which exceed risk-based
cleanup goals (3.6 mg/kg of total carcinogenic PAH compounds,
1,875 mg/kg total PAH, 3,000 mg/kg total phenolics, or 15,750
mg/kg zinc) would be excavated. A clay cap would be placed on
the contaminated area in the slough. Wetlands restoration or
replacement would be required.
The soils would be biologically treated on-site in a 6-acre
treatment facility operated in accordance with RCRA requirements.
Treatment would be conducted similarly to land treatment, but 'in
a lined unit. Treatment would continue until total carcinogenic
PAH concentrations are reduced to at least 36 mg/kg (the maximum
acceptable risk level), total PAH levels are reduced to 1,875
mg/kg, and RCRA Best Demonstrated Available Treatment levels for
naphthalene, pyrene, and phenanthrene are reached. Treatment
would be expected to take between eight and ten years.
The treatment unit would be covered with an impermeable cap
at closure to prevent direct contact with treated soils and to
minimize the migration of rainwater into the unit. Long-term
ground water monitoring, closure and postclosure care of the
treatment facility would be implemented in accordance with RCRA
regulations. Restrictions would be placed on the deed for the
property housing the treatment unit. A temporary storage unit
would be constructed, in accordance with RCRA requirements, to
contain soils awaiting treatment. The excavated areas would be
restored by backfilling with local borrow soils and vegetating.
Contaminated soils at BN-Somers are subject to RCRA
restrictions on land disposal. In order to comply with these
restrictions, no soils could be placed in the treatment unit
after August 8, 1990, unless it is demonstrated that no migration
of contaminants from the treatment zone would occur and a
variance from the land disposal restrictions is granted. Due to
the volume to be treated, it would not be possible to apply all
of the soils by this statutory deadline. Therefore, a no-
migration demonstration would be required. Soils contaminated by
drippage of ties in storage (i.e. in the drip track and slough
areas) have been proposed by EPA for consideration as RCRA i
hazardous wastes. These soils will therefore also be considered
and handled as a hazardous waste during remedial action.
27
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0100638
However, land disposal restrictions have not yet been developed
for these wastes. The EPA is undertaking a land disposal
restriction rulemaking that will specifically apply to soil and
debris. Until that rulemaking is completed, the CERCLA program
will not consider the RCRA land disposal restrictions to be
relevant and appropriate to these soils.
At the completion of this remedial action, health risks
posed by direct contact with contaminated soils would be reduced
to 1 x 10~5 or lower in the excavated areas. Soils in the
treatment unit would achieve a 1 x 10~4 or lower risk level and
would be capped in place. The total capital cost of this
alternative is estimated to be $2,296,000. Operations and
maintenance costs would be $101,000 annually for 10 years and
$47,000 annually for 30 years. The estimated total present worth
cost of this alternative is $3,146,000.
Alternative 3b: Partial Excavation and On-Site Biological
Treatment of Soil. This alternative is the same as Alternative
3a, except that in addition to remediating soils currently
available for direct contact, this alternative would provide
additional protection to surface water bodies by removing
contaminated soils in the slough and beach* areas. The total
excavated soil volume would be 20,000 cubic yards.
Excavation of saturated sediments in the slough and beach
areas would require the use of temporary sheet piling and perhaps
coffer dams. Extensive dewatering would also be necessary.
The size of the soil treatment unit would be expanded to 10
acres. Storage, treatment, restoration, monitoring, closure and
postclosure activities would be the same as Alternative 3a.
Wetlands restoration or replacement would be required. A no-
migration demonstration would be required, as in Alternative 3a.
The total capital cost of this alternative is estimated to
be $4,264,000. The annual operations and maintenance cost would
be $121,000 per year for 10 years and $72,000 per year for 30
years.. The estimated total present worth cost of this
alternative is $5,336,000.
Alternative 3c: Partial Excavation and Off-Site Land Treatment.
This alternative would involve the same volumes and areas of
excavation as Alternative 3b; however, soils would be
biologically treated off-site at Burlington Northern's permitted
land treatment facility in Paradise, Montana. Restoration of
excavated areas at Somers would be the same as in Alternative 3b.
BN has completed a land treatment demonstration at Paradise
and the State has issued a final permit for land treatment of
soils currently at Paradise. A permit modification would be
required to expand the area permitted for land treatment before
Somers soils could be treated there. The EPA Off-Site Policy
28
-------
0100659
would be followed. In accordance with this policy, BN must
implement a ground water corrective action plan at Paradise in
order to be fully compliant with RCRA requirements before
transporting waste from Somers. BN would also need to provide
additional site characterization information on the area of the
facility which would be used to treat Somers waste. The State
would need to issue a permit modification to allow the use of
this additional acreage. The Somers waste would have to meet the
previously established waste application criteria for the
Paradise land treatment unit. A no-migration demonstration may
not be necessary under this alternative, since it is anticipated
that 1) corrective action would begin and a permit modification
could be made before excavation begins at Somers and 2)
application of all of the Somers waste could be made before the
August 8, 1990 deadline. If this were not the case, a no-
migration demonstration would be required.
Under the conditions of the State permit for land treatment
at Paradise (MDHES 1989), treatment must continue until residual
total PAH contamination is reduced to 100 mg/kg. Treatment must
then continue for another year. If a 20% or greater reduction of
total PAH is observed during this time, treatment must continue
until either a decrease of less than 20% from the previous year's
total PAH concentration is observed or total carcinogenic PAH
compounds are reduced to 5 mg/kg and total PAH compounds are
reduced to 10 mg/kg.
In addition to RCRA requirements, EPA, State and U.S.
Department of Transportation requirements would be met during
transport of soils to Paradise.
It is anticipated that excavation and transportation of
soils would take between six months and one year. Land treatment
at Paradise would take an additional four to five years to
achieve the cleanup levels required in the RCRA permit. The
total capital cost of this alternative is estimated to be
$3,182,000. The annual operations and maintenance cost is
estimated to be $152,000 for five years and $53,000 for 30 years.
The estimated present worth cost of this alternative is estimated
to be $4,216,000.
Alternative 3d: Deep Excavation and On-Site Biological Treatment
of Soils. This alternative would involve the same activities as
Alternative 3b, except that it would include excavation of
contaminated soils to a depth of 30 feet in the CERCLA lagoon,
subsurface soils downgradient from the CERCLA lagoon, and
excavation to a depth of 20 feet in the former swamp pond.
Excavation below the water table would require the use of sheet
piling and involve extensive dewatering. Removal, treatment and
disposal of the generated water would be required. Excavation of
the subsurface soils downgradient from the CERCLA lagoon would
require that two private houses be temporarily relocated. Since
29
-------
0100600
BN does not own these properties, access would have to be
obtained.
A total soil volume of 106,400 cubic yards would be
excavated. Approximately 22 acres on-site would be used for
biological treatment of the soils. Storage, treatment,
restoration, monitoring, closure and postclosure activities would
be th'e same as Alternative 3a. The land disposal restrictions
described under Alternative 3a would also apply and a no-
migration demonstration would have to be made. Institutional
controls on the use of ground water downgradient from the CERCLA
lagoon would be implemented until ground water quality has
returned to acceptable levels. These controls could take the
form of notice in deed of the presence of hazardous waste in
ground water beneath the property and a prohibition on
construction of new wells for potable use.
Due to the greatly increased volume of soils to be treated,
this alternative would take 16 to 20 years to complete. The
total estimated capital cost would be $14,489,000 and the annual
operations and maintenance cost would be $142,000 for 16 years
and $79,000 for 30 years. The estimated total present worth cost
of this alternative is $15,363,000.
Alternative 5: Partial Excavation and On-Site Containment. This
alternative would involve construction of a two-acre, lined
disposal facility on the Site in accordance with RCRA
regulations. The disposal facility would be double-lined with
high density polyethylene membrane and clay liners. Leachate
collection and leak detection systems would be installed. A
volume of 20,000 cubic yards of contaminated soils (the same
soils described under Alternative 3b) would be excavated. The
soils would be placed in the disposal facility after
stabilization, but without treatment.
The excavated areas would be restored by backfilling with
local borrow soils and vegetating. Disturbed wetlands would be
replaced or restored. Ground water monitoring wells would be
installed downgradient of the facility and long-term monitoring
and maintenance would be implemented in accordance with RCRA
requirements. Restrictions on the use of the property occupied
by the landfill would be placed in the deed.
Residual contamination in source areas would be reduced to
the same concentrations as provided in Alternative 3b by
excavation. However, because no treatment would be involved, no
reduction in toxicity would occur.
The time frame necessary to implement this alternative would
be one year. Since all of the soils could be placed in the
landfill before August 8, 1990, a variance to the land disposal
restrictions would not be required. The total capital costs
30
-------
0100651
involved are-estimated at $2,126,000 and the annual operations
and maintenance cost are estimated at $22,000 for 30 years. The
total present worth cost would be $2,333,000.
Alternative 7a: Partial Excavation and On-Site Thermal
treatment.This alternative would involve construction of a
temporary incinerator on the Site. A volume of 20,000 cubic
yards of contaminated soils (the same soils as described under
Alternative 3b) would be excavated and processed to remove as
much free oil and water as practicable. The recovered oil would
be shipped to a creosote manufacturer for refining and recycling.
Any wastewater generated would be managed in accordance with RCRA
regulations. The processed soils would be incinerated. Pilot
testing of an infrared conveyer furnace was conducted on
creosote-contaminated soils from the BN Paradise facility. This
method was found to be an effective way of treating such wastes.
The actual thermal treatment unit used in this alternative would
be determined during remedial design. Trial burns would be
required prior to initiation of the project in order to refine
engineering specifications. During operation, air emissions
would be controlled in accordance with State and EPA emissions'
standards. Wastewater produced from the air pollution control
system would be treated on site.
The ash residue from incineration would meet RCRA Best
Demonstrated Available Technology concentrations. It would be
landfilled in a new 2-acre facility on site and capped in
accordance with RCRA regulations to reduce migration of liquids
through the landfilled material. Due to generally low
concentrations of metals in the contaminated soils, reduction of
the mobility of metals in the treated ash is not expected to be
required. However, if the immobilization.of metals were found to
be necessary, lime material would be added to stabilize the
soils. Ground water monitoring wells would be installed
upgradient and downgradient from the disposal facility and long-
term monitoring, maintenance and restrictions on the use of the
property would be implemented. However, these activities would
not be necessary if the ash could be delisted as a hazardous
waste. Since incineration would treat the contaminated soils to
RCRA Best Demonstrated Available Technology levels, no variance
from the land disposal restrictions would be required prior to
landfilling the ash,
A period of two years would be required to complete
incineration of the excavated soils. During this time, soils
awaiting treatment would be stockpiled on site. The total
estimated capital cost of this alternative would be $15,998,000.
The annual operations and maintenance cost would be $26,000 for
20 years. The total present worth cost of this alternative is
estimated to be $16,219,000.
31
-------
01G0632
Alternative 7b: Deep Excavation and On-Site Thermal Treatment.
This alternative would involve the same areas of excavation and
volumes described in Alternative 3d, except that excavated soils
would be incinerated on-site. As in Alternative 3d, temporary
relocation of two houses would be necessary to complete the
excavations. Excavated areas would be restored as in Alternative
3d. The operation of the incinerator and disposal of the ash
residue would be completed as in Alternative 7a, except that a
10-acre landfill would be required. The total time required to
treat the excavated soils would be 2 years. This period is the
same as Alternative 7a because a larger capacity incinerator
would be used.
The total estimated capital cost of this alternative would
be $62,643,000. Annual operations and maintenance costs would be
$36,000 for 30 years. The total present worth cost of this
alternative is estimated to be $62,909,000.
Alternatives for Contaminated Ground Water
Table 4 lists the alternatives considered in the detailed
analysis for ground water remediation and classifies aspects of
the alternatives into treatment, containment, and institutional
control components.
Alternative 1: No Action. This alternative involves no
engineering controls, but it does provide for monitoring
contaminant pathways and instituting controls to prevent future
development of water supply wells in the areas of ground water
contamination.
Three new ground water monitoring wells would be installed.
One of these wells would be completed in the lower artesian
aquifer. These new wells and 11 existing wells would be sampled
on a quarterly basis for PAH and phenolics. In addition, samples
would be collected from the Somers municipal water supply on a
quarterly basis. If results indicate a significant increase in
contaminant migration or a decrease in the quality of the
municipal supply, appropriate response measures would be
developed and implemented. These might include implementation of
ground water remediation and provision of an alternate municipal
water supply.
Institutional controls on the construction of new wells
downgradient from the CERCLA lagoon and in the swamp pond area
would be implemented and maintained until ground water quality
returns to acceptable levels. These controls could take the form
of notice in deed of the presence of hazardous waste in ground
water beneath the property and a prohibition on construction of
new wells for potable use, if enacted by the Somers Water
District. Institutional controls are not considered completely
reliable. Under this alternative, ground water, and possibly
32
-------
TABLE A
GROUND WATER ALTERNATIVES
ALT 1
No Action
^FjfTHNOIjQGi TYPE
HFMP»TAJ. OPTION PROCESS OPTION
BIOLOGICAL GW In-Sltu
TREATMENT
CHEMICAL GW Peroxlde/UV
TREATMENT Oxidation
PHYSICAL GW Oil/Water Separation
TREATMENT
Hot Water Flushing
GROUND WATER MONITORING X
INSTITUTIONAL CONTROLS X
ALT 2
Cnem/Phys/
Hot Water
X
X
X
X
X
ALT 5
In-Sltu
Bio Trmt
X
X
X
X
X
ALT 6
In-Sltu
Bio Trmt/
Hot Water
X
X
X
X
X
X
c
c
o
c
o
-------
0100634
surface water would continue to degrade as existing plumes
migrate. ARARs would not be met by this alternative.
Implementation of this alternative is expected to take less
than six months at a total estimated capital cost of $79,000.
Annual operations and maintenance costs would be $65,000 for 30
years. The total present worth cost is estimated to be $692,000.
Alternative 2: Hot Water Flushing with Physical and Chemical
Ground Water Treatment. This alternative would involve
installation and operation of an innovative hot water flushing
system in conjunction with conventional ground water treatment.
Injection and recovery wells would be installed in and around the
CERCLA lagoon and former swamp pond areas. Temporary
restrictions on the use of ground water in the affected areas
would be implemented.
Creosote contamination in the aquifer would be flushed by
hot water, and the recovered ground water would be treated by
oil/water separation and an ozone/ultraviolet (UV) or hydrogen
peroxide/UV system. Recovered oil would be shipped to a creosote
manufacturer for recycling or would be treated under one of the
soil alternatives. Hot water flushing is an unproven technology
for creosote wastes. It may be difficult to implement in the
complex hydrogeological conditions and low permeability aquifer
at Somers. Pilot testing would be conducted to determine the
practicability of this option and to develop engineering plans.
The cleanup and treatment levels would reduce the total PAH
concentrations in the aquifer to 0.3 ug/1 and the total
carcinogenic PAH levels to 0.03 ug/1. Appropriate Water Quality
Criteria and Maximum Contaminant Levels would also be met. The
treated water would be reinjected into the aquifer beneath the
main tie plant through an infiltration gallery. Excess treated
water would be reinjected in a second infiltration gallery on the
tie plant property or discharged to the Lakeside publicly owned
treatment works (POTW), if an agreement could be reached with
this facility. Ground water wells and the Somers municipal water
supply would be sampled semi-annually to monitor contaminant
migration and the performance of the remedy. Actions taken in
the swamp area would need to comply with regulations governing
actions in wetlands and floodplains. Discharge of treated water
would have to be done in compliance with the Clean Water Act and
Underground Injection Control programs, and the Montana non-
degradation standards.
This alternative would be completed in approximately 20
years. Once completed, the residual carcinogenic risk to human
health from consumption of affected ground water would be reduced
to 1 x 10~5. A cleanup concentration of 1 x 10~^ was considered
but not implemented because current analytical methods.are unable
to reliably detect total carcinogenic PAH concentrations of 0.003
33
-------
0100635
ug/l. The cleanup concentration for total PAH was set below the
risJc levels associated only with systemic effects in order to
protect against certain effects from noncarcinogenic PAH
compounds. As stated earlier', these may be cancer initiators or
co-carcinogens.
The total capital costs involved are estimated to be
$2,594,000. Annual operations and maintenance costs would be
$690,000 for 20 years. Total present worth costs are estimated
at $8,468,000.
Alternative 5: In-Situ Biological Ground Water Treatment. This
alternative would involve installing an in-situ treatment system.
The system extracts ground water through wells, adds nutrients
and oxygen, and injects the water into the aquifer. It also
monitors and controls the ground water gradient and contaminant
plume. The biological treatment would stimulate growth of the
naturally-occurring bacteria in the ground water. The bacteria
would digest contaminants in the water and convert them into
nonhazardous constituents. Injection and recovery wells would be
installed in the CERCLA lagoon and swamp areas. After water is
pumped from the wells, it would be treated in an oil/water
separator and a ozone/UV or hydrogen peroxide/UV chemical
reactor. Aquifer and ground water cleanup concentrations would
be the same as Alternative 2. A portion of the treated water
would be reinjected through an infiltration gallery after
addition of nutrients and peroxide. The remaining treated water
would be discharged to the Lakeside POTW, if an agreement can be
reached with the facility, or into another infiltration gallery
on the tie plant property. Ground water monitoring would be the
same as in Alternative 2.
As with Alternative 2, pilot testing of this alternative
would be required to demonstrate the technology's practicability
and to establish design and operating parameters. Administrative
requirements would be the same as for Alternative 2. Temporary
institutional controls on the use of affected water would be
implemented.
The estimated time frame for completion of this alternative
is 15 years. The total estimated capital costs involved would be
$2,197,000. Annual operations and maintenance costs would be
$540,000 for 15 years. Total present worth costs are estimated
to be $6,304,000.
Alternative 6: Hot Water Flushing with In-Situ Biological
Treatment. This alternative would combine the hot water flushing
technology of Alternative 2 with the in-situ biological treatment
of Alternative 5. The areas remediated would be the same as in
Alternatives 2 and 5. During the hot water flushing phase,
produced water would be treated in an oil/water separator and an
ozone/UV or peroxide/UV chemical reactor. After hot water
34
-------
0100G2G
flushing has removed the maximum practicable amount of
contamination, the in-situ treatment process would be implemented
to remove residual contamination. Aquifer and ground water
cleanup concentrations would be the same as Alternatives 2 and 5.
Pilot testing would be required to establish the technology's
effectiveness and design and operating parameters prior to
implementation. The administrative requirements of this
alternative would be the same as for Alternatives 2 and 5.
Temporary institutional controls would be used to prevent use of
ground water in affected areas.
The total time to complete this alternative is estimated to
be ten years. The total capital cost is estimated to be
$2,617,000. Annual operations and maintenance costs would be
$690,000 for two years and $540,000 for eight years. The total
present worth cost is estimated to be $6,695,000.
VIII. Summary of the Comparative Analysis of Alternatives
This section summarizes the relative performance of the
alternatives described above in relation to the nine evaluation
criteria specified in OSWER Directive 9335.3-01 (U.S.EPA 1988).
Although soil and ground water alternatives are evaluated
separately, the remedy selection process in this Record of
Decision treats both soil/sediment and ground water components as
a single response action. Additional information is presented in
the Feasibility Study for the BN-Somers site (Remediation
Technologies 1989, Vol. III).
Analysis of Soil Alternatives
Overall protection of human health and the environment. All the
alternatives, with the exception of the "no action" alternative
would assure adequate protection of human health and the
environment by eliminating, reducing or controlling risk through
treatment or engineering controls. Alternatives 3a, 3b, 3c, and
7a would remove and treat soils that are contaminated above risk-
based concentrations and that are available for direct contact.
By removing and treating these soils, the risk of direct contact
would be eliminated and the source of contaminants to ground
water would be reduced.
Alternatives 3d and 7b, which involve deep excavation of
source areas, would provide better protection than partial
excavation if ground water treatment were not found to be
successful. Alternative 5 removes the direct contact threat by
excavating the contaminated soils and placing them in a lined
landfill protected by an impermeable cap. Alternative 3a does
not include remediation of beach sediments and therefore provides
somewhat less long-term environmental protection than other
alternatives.
35
-------
U1U0627
Because the "no action" alternative would allow continued
impacts on ground water from contaminated soils, it is not
considered further in this analysis.
Compliance vith ARARs. All alternatives could be designed to
meet the applicable or relevant and appropriate requirements of
Federal and State environmental laws. Alternatives which involve
on-site biological treatment (3a, 3b, and 3d) would require a
demonstration that no migration would occur outside of the
treatment unit for as long as the wastes remain hazardous. The
use of a lined treatment unit should help facilitate this
demonstration. In Alternative 3c (off-site land treatment) it is
expected that all of the excavated soils could be applied to the
treatment unit before the effective date of the land disposal
restrictions. If this were not the case, a demonstration of no
migration would be required. Alternatives 7a and 7b
(incineration) would reduce contaminant concentrations
sufficiently to allow for land disposal of residual ash in
compliance with the land disposal restrictions. The on-site
containment alternative could be completed prior to the effective
date of the land disposal restrictions.
Long-term effectiveness and permanence. Alternatives 3a, 3b, 3c,
and 3d would permanently provide protection of human health and
the environment by removing all soils that exceed risk-based
concentrations and that are available for direct contact. The
soils would be biologically treated to reduce contaminant
concentrations to acceptable levels. On-site containment would
not be considered a permanent remedy for two reasons. First,
portions of the cap might need to be replaced over time, and
second, the liner may fail and allow a release of contaminants
from the untreated soils. The same concerns apply to a liner and
cap associated with a land treatment unit, however, the waste
would be permanently treated and the liner would only be
necessary during the period of treatment. Once wastes are
treated to health-based levels, and if leachate also meets
health-based levels, the cap would only be necessary to prevent
infiltration and pooling of water in the unit. Incineration
would permanently destroy most of the organic contamination;
however, the ash would need to be landfilled, unless it can be
demonstrated to be non-hazardous.
Reduction of toxicity, mobility, or volume. All of the
alternatives except 5 would significantly and permanently reduce
the toxicity of the soils through treatment. On-site
incineration or biological treatment would be required to
continue until total carcinogenic PAH compounds are reduced to
below 36 mg/kg and RCRA Best Demonstrated Available Technology
concentrations for naphthalene, phenanthrene, and pyrene are met.
Alternative 3c would require treatment to levels specified in th^
RCRA permit. Alternative 5 would reduce the mobility of the
contaminants by containment and capping, but it does not involve
36
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0100628
treatment of waste materials. Most of the treatment alternatives
reduce mobility, although air emissions may occur under the
thermal or biological treatment options. No significant volume
reduction would occur with any of the alternatives.
Short-term effectiveness. Sufficient acreage is available at
Paradise to begin treatment of all the excavated soils under
Alternative 3c immediately after excavation. There would be some
minor, short-term risk of exposure to the community during
transportation of the contaminated soils. Alternatives 3d and 7b
would provide the fastest protection of ground water through deep
excavation of the source areas. Some short-term risk of releases
to Flathead Lake would be associated with beach and swamp area
excavations. Biological soil treatment under the deep excavation
option (Alternative 3d) would take six to 15 years longer than
the other alternatives, due to the large soil volume, if almost
the entire tie plant property were used for treatment.
Alternative 5 would be effective in a relatively short time since
contaminated soils would be.placed directly into an impoundment
and capped. All of the alternatives would pose some short-te±m
risks of exposure to volatile PAH compounds during excavation.
The capacity for on-site biological or therma»l treatment is
limited. Therefore, under Alternatives 3a, 3b, 3d, 7a, and 7b,
contaminated soils would be stockpiled and would be available for
direct contact until treatment has been completed. In addition,
exposure to air emissions from an incinerator or from a land
treatment unit is possible. Alternative 3d would involve the
longest exposure duration due to stockpiled soils and possible
air emissions, because of the larger volumes of stored soils and
the increased acreage of the biological treatment unit.
Implementability. All of the soil treatment and containment
alternatives considered involve technologies that have been used
successfully to solve similar contaminant problems at other
Superfund sites. Demonstrations of the effectiveness of both
incineration and land treatment were conducted on soils
contaminated with creosote wastes from the BN-Paradise facility.
The experience necessary to construct the remedies are available.
A mobile incinerator could be obtained quickly. Alternatives
involving deep excavation would require the use of construction
methods that address the need to excavate below the water table.
The same would be true of excavation in the slough and beach
areas. Beach and swamp excavations would also have to protect
against a possible blow-out due to the proximity of Flathead
Lake. Alternatives 3d and 7b would also require the temporary
relocation of two houses. Alternative 3c would require a
modification to the State RCRA permit for the BN-Paradise land
treatment facility in order to allow additional acreage for
treatment. Ground water corrective action must begin at the
Paradise facility before waste from Somers could be brought to
the Site. This would be necessary to comply with the EPA Off-
37
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0100629
Site Policy. .On-site land treatment (Alternatives 3a, b, and d),
and possibly off-site land treatment (Alternative 3c), would
require a demonstration that no migration of hazardous
constituents would occur from the treatment unit. Alternative 5
could be completed in the shortest period of time followed by the
incineration alternatives (7a and 7b) and the off-site land
treatment alternative (3c).
Cost. Table 5 provides a comparison of estimated capital,
operation and maintenance, and net present worth costs of the
various alternatives. Other than the no-action alternative,
Alternative 5 would require the least capital outlay followed in
order by Alternatives 3a, 3c, 3b, 3d, 7a, and 7b. Alternative 5
would also have the lowest present worth cost followed in order
by Alternatives 3a, 3c, 3b, 3d, 7a, and 7b.
State Acceptance. The Montana Department of Health and
Environmental Sciences (MDHES) concurred with EPA's proposed plan
to land treat contaminated soils off-site, but initially withheld
judgement on the actual treatment location. After receiving ,
substantial public comment in opposition to Alternative 3c (off-
site land treatment at Paradise), the State expressed support for
Alternative 3b, on-site biological treatment, or treatment at
another undetermined off-site location. The State also expressed
support for incineration as a contingency alternative if ground
water remediation were found to be impracticable.
Community Acceptance. EPA received substantial public comment in
opposition to Alternative 3c, land treatment at Paradise. Public
commentors were also opposed to Alternatives 7a and 7b, on-site
incineration, but were generally supportive of on-site biological
treatment. The public also commented that beach sediments should
not be included in the areas of the Site to be excavated.
Analysis of Ground Water Alternatives
Overall protection of human health and the environment. All of
the alternatives, with the exception of the "no action"
alternative, would provide adequate protection of human health
and the environment by eliminating, reducing, or controlling risk
through treatment, engineering controls and institutional
controls. Alternative 2 would remove creosote contamination from
the aquifer by hot water flushing and would chemically treat the
contamination at the surface. Alternative 5 would biologically
treat the contamination in-situ. Alternative 6 would involve a
combination of hot water flushing and in-situ biological
treatment. In all of the treatment alternatives, pumping wells
would provide hydraulic controls to prevent contaminated ground
water from reaching Flathead Lake. Temporary institutional
controls would prevent the use of contaminated portions of the
aquifer as a drinking water supply.
38
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0100670-
TABLE 5
SUMMARY OF ESTIMATED REMEDIAL ACTION COSTS
FOR SOIL ALTERNATIVES
Soil ' Total Annual Total Present
Alternative Capital Cost O&M* Cost Worth Cost
1 $238,000 $2,500 $262,000
(30 years)
3a $2,296,000 $101,000 $3,146,000
(10 years)
$47,000
(30 years)
3b $4,264,000 $121,000 $5,336,000
(10 years)
$72,000
(30 years)
3c $3,182,000 $152,000 $4,216,000
(5 years)
$53,000
(30 years)
3d $14,489,000 $142,000 $15,363,000
(16 years)
$79,000
(30 years)
5 $2,126,000 $22,000 $2,333,000
(30 years)
7a $15,998,000 $26,000 $16,219,000
(30 years)
7b $62,643,000 . $36,000 $62,909,000
(30 years)
* O&M = Operations and Maintenance
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0100671
The "no action" alternative does not prevent continued
degradation of ground water resources or continued adverse
impacts on Flathead Lake; therefore it is not considered further
as a remedial option.
Compliance vith ARARs. All of the treatment alternatives can be
designed to comply with all ARARs. The currently expanding
ground water contaminant plume is considered a violation of the
State's nondegradation standards; however, once ground water
treatment is instituted, the plume will no longer be allowed to
expand and this ARAR will also be met.
Long-term effectiveness and permanence. All of the ground water
treatment alternatives are innovative and would require pilot
testing to establish their practicability and site-specific
design and operating parameters. It is possible that ground
water remediation will be found to be effective in the CERCLA
lagoon area but not in the swamp area because of aquifer
permeabilities. If effective, all of these alternatives would
provide long-term effectiveness and permanence by removing and
degrading contaminants.
Reduction of toxicity, mobility, or volume. All of the treatment
methods considered would reduce the toxicity, mobility and volume
of contamination. Depending on the length of time each system is
operated, the various systems can all reach the treatment '
concentrations of 0.03 ug/1 total carcinogenic PAH, 0.3 ug/1
total PAH, as well as Water Quality Criteria, Drinking Water
Standards and Maximum Contaminant Levels.
Short-term effectiveness. Alternative 6 could remediate the
aquifer in the shortest period of time. Both Alternative 2 and
Alternative 6 would be effective in the short term because hot
water flushing would quickly remove the heaviest contamination
from the aquifer. However, Alternative 2 would have to be
operated for 5 to 10 years longer than the methods involving in-
situ treatment to achieve the same cleanup levels. Institutional
controls on the use of contaminated ground water would be
necessary to provide short-term protection during the remediation
period in all of the treatment alternatives.
Implementability. All of the methods considered would require
pilot testing to determine practicability and design and
operating parameters. It is possible that ground water
remediation will prove to be impracticable at the Site, or may be
practicable only in the CERCLA lagoon area. Pilot testing is
expected to take between six months and one year. Once
implemented, institutional controls on the use of affected ground
water would be required until treatment is complete. An
agreement with the Lakeside POTW would have to be obtained, or
all of the produced water would have to be reinjected at the BN-
Somers site.
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01006
72
Cost. Table 6 presents the estimated capital, operation and
maintenance costs, and net present worth costs for each
alternative. With the exception of the no-action alternative,
Alternative 5 would require the least capital outlay followed in
order by Alternatives 2 and 6. Alternative 5 involves the lowest
present net worth cost, followed in order by Alternatives 6 and
2.
State acceptance. The Montana Department of Health and
Environmental Sciences concurred with EPA's proposed plan, which
involved hot water flushing combined with in-situ biological
treatment (Ground Water Alternative 6).
Community acceptance. The community was generally supportive of
Alternative 6, but expressed concerns about possible nutrient
additions to Flathead Lake and resultant algae blooms.
IX. The Selected Remedies
Based upon consideration of the requirements of CERCLA, a
detailed evaluation of the alternatives, and public comments both
the EPA and the State have determined that a modified Soil
Alternative 3b (excavation and on-site biological treatment), and
Ground Water Alternative 6 (hot water flushing and surface
chemical treatment followed by in-situ biological treatment)
comprise the most appropriate remedy for the BN-Somers site.
These alternatives and the associated response objectives are
discussed below.
Modified Soil Alternative 3b
Soil Alternative 3b involved excavation of approximately
20,000 cubic yards of creosote and zinc contaminated soils in the
CERCLA lagoon, drip track, drainage ditch, beneath the retort
building, and in the slough and beach areas. EPA has selected a
modified Alternative 3b, which includes excavation of all of
these areas except the beach sediments, for a total excavated
volume of approximately 11,700 cubic yards. After consideration
of public comment and based on its own engineering evaluation,
EPA agreed that the risks to Flathead Lake from a beach
excavation outweighed the benefits of removing the contaminated
sediments. The contaminated beach sediments are currently
covered by a few feet of clean sand. These sediments will be
reviewed every five years to ensure that leaving them in place
continues to be protective.
Under -the soil component of the selected remedy, a portion
of contaminated soils will remain below the water table in the
CERCLA lagoon and swamp. These soils will be treated as part of
the ground water component of the remedy. A temporary storage
unit will be constructed on-site and operated according to RCRA
40
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0100673
TABLE 6
SUMMARY OF REMEDIAL ACTION COSTS
FOR GROUND WATER ALTERNATIVES
Ground Water Total Annual Total Present
Alternative Capital Cost O&M* Cost Worth Cost
1
2
5
1
6
$79,000 $65,000
(30 years)
$2,594,000 $690,000
(20 years)
$2,197,000 $540,000
( 1 5 years)
1
$2,617,000 $690,000
( 2 years )
$540,000
(8 years)
$692,000
$8,468,000
$6,304,000
$6,695,000
* O&M - Operations and Maintenance
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01006?:
requirements to. contain soils awaiting land treatment. The
excavated areas (other than wetlands) will be restored by
backfilling with clean borrow soils and vegetating. Replacement
or restoration of wetlands destroyed during the 1985 Emergency
Removal action at Somers will be accomplished, as well as
replacement or restoration of any additional wetlands lost during
the final remedial action.
The excavated contaminated soils will be biologically
treated on-site in a 10-acre lined land treatment facility. A
land treatment demonstration will be conducted prior to the
application of any waste to the treatment unit. Treatment of all
of the soils to acceptable health-based levels is expected to
take between eight and ten years. Toxicity testing will be
conducted to ensure that the overall toxicity of the soils is
adequately reduced by treatment. If, at completion of treatment,
any leachate collected in the unit is within the ground water
cleanup concentrations established in this Record of Decision,
the facility may be closed by perforating the liner system and
covering the unit with a vegetative cap. However, if the
leachate contains contaminant concentrations greater than the
ground water cleanup concentrations, the land treatment unit will
be'covered with an impermeable cap at closure to minimize the
migration of rainwater into the unit and leaching of
contaminants. Unless and until soils are treated to background
contaminant concentrations, up to 30 years of ground water
monitoring and post-closure care of the treatment facility will
be implemented in accordance with RCRA. If hazardous
constituents remain in the treatment unit at closure,
restrictions will be placed on the deed for the property housing
the unit.
It is anticipated that the first application of contaminated
soils to the treatment unit will be made before the August 8,
1990, effective date of the RCRA land disposal restrictions. Any
subsequent applications occurring after the effective date will
necessitate a demonstration that no migration of hazardous
constituents above health-based levels will occur from the
treatment unit. This demonstration will be made before any waste
is applied to the land treatment unit in order to ensure that the
remedy may proceed after the effective date of the land disposal
restrictions. Evidence from the land treatment demonstration
conducted at BN's Paradise facility indicates that if the Somers
unit is operated similarly, no migration will occur to ground
water. The use of a liner will also help in making this
demonstration. Modeling of possible releases to air will be made
as an initial demonstration of no-migration. Actual monitoring
of treatment operations will be used to verify the no-migration
demonstration.
Placement of contaminated soils in the temporary storage
unit will also be subject to the RCRA land disposal restrictions
41
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0100675
if such placement occurs after August 8, 1990. If the soils are
placed into a waste pile, they will first be pretreated in order
to obtain a treatability variance from the land disposal
restrictions or a demonstration will be made that hazardous
constituents will not migrate from the unit above health-based
levels. Otherwise, the soils will be placed in a storage tank
until treatment can occur.
Response Objectives - Soil
The response objectives for soil remediation are to reduce
exposure from direct contact to an acceptable level and to ensure
that the migration of contaminants to ground water is minimized.
Both Federal and State ARARs were reviewed to determine if
there are any standards that indicate the acceptable
concentrations for contaminants in soils. This review indicated
that no Federal or State standards exist for these compounds in
soils. Therefore, the soil cleanup levels were determined by the
risk assessment process. Table 7 presents the cleanup
concentrations which were established for the various compounds;
all of these concentrations must be achieved. Any soils at the
Site which exceed concentrations of 3.6 mg/kg total carcinogenic
PAH, 1,875 mg/kg total PAH, 15,750 mg/kg zinc, or 3,000 mg/kg
phenolics will be excavated. The total carcinogenic PAH
concentration equates to a risk level of one in one hundred
thousand (1 x 10~5). The total PAH, zinc, and phenolic
concentrations are considered protective against systemic
(noncarcinogenic) effects.
The establishment of the excavation cleanup concentration
for total carcinogenic PAH considers the minimum individual PAH
constituent concentration which can be detected in soils. This
concentration is approximately 1 mg/kg. For this reason, a one
in one million (1 x 10~6) cleanup (equating to a total
carcinogenic PAH concentration of 0.36 mg/kg) cannot be verified.
At the completion of remedial action, health risks posed by
direct contact with soils will be reduced to at least 1 x 10~5,
which can be verified analytically.
The initial treatment of soils will reduce total
carcinogenic PAH concentrations to 36 mg/kg and will reach RCRA
Best Demonstrated Available Technology levels of 7.98 mg/kg for
naphthalene, 7.98 mg/kg for phenanthrene, and 7.28 mg/kg for
pyrene. The treatment concentration of 36 mg/kg equates to a one
in ten thousand (1 x 10"^) risk level, the maximum acceptable
carcinogenic risk according to EPA standards. EPA's goal is a
risk level of 1 x 10~6; therefore, once the initial treatment
levels are achieved, treatment will continue until the decrease
in total PAH has been less than 20% from the previous year, or
background concentrations are reached. At this point, another
application of soils may be made or the facility may be closed.
42
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0100673
TABLE 7
REMEDIATION CONCENTRATIONS
SELECTED REMEDIES CHEMICAL
MEDIA:
REMEDIATION
CONCENTRATIONS
Soil - Excavation:
Carginogenic PAH
(1 X 10~5 risk)
Total PAH
Total phenolics
Zinc
Human
Health
3.6 mg/kg*
1,875 mg/kg*
3,000 mg/kg*
15,750 mg/kg*
Aquatic
Life
Soil - Initial treatment residuals:1
Carcinogenic PAH
(1 x 10~4 risk)
Naphthalene
Phenanthrene
Pyrene
Ground Water:
Carcinogenic PAH
(1 x 10~5 risk)
Total PAH
Acenaphthene
Fluoranthene
Naphthalene
Benzene
Phenol
Total Phenolics
Zinc
36 mg/kg*
7.98 mg/kg+
7.98 mg/kg+
7.28 mg/kg+
0.030 ug/1**
0.300
20
42
5
3,500
15,000
5,000
ug/1*
ug/1**
ug/1**
ug/1***
ug/1**
ug/1*
ug/1****
620 ug/1**
2500 ug/1**
110 ug/1**
1 After achieving initial treatment residuals, land treatment
will continue until the net reduction in total PAH
concentration for a particular year is less than 20% compared
to the previous year. Incineration will meet RCRA requirements
for a destruction efficiency of 99.99%, in addition to the
initial treatment residuals.
Key to sources of remediation goals:
* Risk Assessment
** Clean Water Act Water Quality Criterion
*** Safe Drinking Water Act Maximum Contaminant Level
****Safe Drinking Water Act Drinking Water Standard
+ RCRA Best Demonstrated Available Technology Level
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0100677
If background concentrations can be reached, certain RCRA
postclosure care requirements would not be necessary. Based on
the land treatment demonstration conducted on soils contaminated
with creosote waste at BN's Paradise facility, it is estimated
that each waste application will require four to five years to
treat.
Ground Water Alternative 6
Ground water Alternative 6 involves hot water flushing of
contaminated ground water, ozone/UV or peroxide/UV treatment at
the surface, and in-situ biological treatment of residual
contamination. Injection and recovery wells will be installed in
the CERCLA lagoon and former swamp pond areas. Temporary
institutional controls designed to restrict the use of ground
water in the affected areas will be implemented. Creosote
contamination in the aquifer will be flushed out by hot water and
the recovered ground water will be treated in a chemical reactor.
Once hot water flushing has removed the maximum practicable
amount of contamination, an in-situ biological treatment process
will be implemented to remove residual contamination. Treated
water will be injected into the aquifer beneath the main tie
plant through an infiltration gallery or used to irrigate the
land treatment unit. Excess water will be discharged to the
Lakeside POTW, if possible. Recovered oil will be shipped to a
creosote manufacturer for recycling or handled with the soil
alternative. Ground water wells and the Somers municipal supply
will be monitored semi-annually until cleanup concentrations are
achieved.
Hot water flushing and in-situ treatment are unproven
technologies for creosote wastes. They may be difficult to
implement in the complex hydrogeological system and low
permeability aquifer at Somers. Pilot testing will be conducted
so that EPA may determine the practicability, design and
operational constraints of the process.
Response Objectives - Ground Water
The response objectives for ground water remediation are to
reduce, by treatment, potential exposures from ground water
ingestion and to ensure contaminants in ground water do not
adversely affect the quality of Flathead Lake.
Both Federal and State ARARs were reviewed to determine if
there are any standards indicating the acceptable concentrations
contaminants in ground water. This review identified Water
Quality Criteria for total carcinogenic PAHs, acenaphthene,
fluoranthene, naphthalene, benzene, phenol, and zinc, a Maximum
Contaminant Level for benzene and a Secondary Drinking Water
Standard for zinc. These standards are summarized in Table i.
Table 7 presents the cleanup concentrations established for the
43
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0100678
remedial action. These concentrations must be met throughout the
contaminant.plumes.
A one in one hundred thousand (1 x 10~5) cleanup
concentration of 0.03 ug/1 will be set for total carcinogenic
PAH. A concentration of 0.003 ug/1 (one in a million or 1 x 1 0~6
risk level) was considered, but not selected because the
analytical methods available do not reliably allow for
verification of this total concentration. The cleanup
concentration for total PAH compounds, considering systemic but
not carcinogenic effects, is 0.3 ug/1, based on risk assessment.
This concentration includes a safety factor to provide additional
protection against cancer initiators or co-carcinogens as well as
against other carcinogenic PAH compounds, such as the nitrogen-
bearing heterocyclics which were not typically analyzed for at
the Site.
The Water Quality Criteria of 110 ug/1 for zinc and 2,560
ug/1 for phenol will also be used as cleanup concentrations
because of the potential for ground water to discharge directly
into Flathead Lake. The Water Quality Criteria for acenaphthene
and naphthalene will automatically be met by achievement of the
total PAH cleanup concentration.
Contingency Remedies
Traditional ground water pump and treat methods would not be
effective for aquifer remediation at Somers because of the low
permeability of the contaminated aquifer at the Site and the
nature of creosote contamination. Ground water Alternative 6
involves two innovative technologies, hot water flushing and in-
situ biological treatment. These are the most promising methods
given the hydrogeologic conditions at Somers. Both technologies
require pilot testing to determine their practicability at the
Site. Pilot tests will be completed before any soils are applied
to the land treatment unit. At the conclusion of pilot testing,
EPA will use the criteria established in OSWER Directive 9355.3-
01 (USEPA 1988) to determine whether ground water remediation
will be practicable at the Site.
Contingency Remedy A. If pilot testing indicates that
ground water Alternative 6 would not be practicable, a modified
soil Alternative 7b involving deep excavation (excluding beach
sediments) and incineration will be implemented. In this case,
the same areas described above for modified soil Alternative 3b
will be excavated with the addition of approximately a 20 foot
excavation in the swamp area and approximately a 30 foot
excavation in the CERCLA lagoon and downgradient areas. The
volume to be excavated will total approximately 98,300 cubic
yards. This deeper excavation will be designed to remove as much
contaminated material as possible below the water table, in order
to reduce the source of contamination to ground water.
44
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0100679
Incineration was chosen over biological treatment as the I
technology to. treat these soils because the volume excavated
could be treated in 2 years by incineration, but would take at
least 16 years to biologically treat on site using essentially
all of the available tie plant property for land treatment.
Because of the proximity of homes to the areas which would be
used for biological treatment, that option was not chosen.
Biological treatment using the 10-acre site outlined in
Alternative 3b would allow a visual and noise buffer zone;
however treatment would take over 50 years. If the large soil
volume considered under this contingency remedy were land
treated, the liner systems for both the treatment and soil
storage units would have to be maintained for up to 50 years.
The reliability of these materials would tend to be reduced over
extended periods of operation. Incineration was chosen over land
treatment because thermal treatment can achieve the same or
better treatment levels in a much shorter period of time without
requiring the long-term management of hazardous waste storage and
treatment facilities.
Excavation below the water table would require sheet piling
and extensive dewatering and treatment. Excavation downgradient
from the CERCLA lagoon would require the temporary relocation of
two'houses. The excavated soils would be incinerated on the Site
after removing as much water and free oil as possible. The oil
would be shipped to a creosote manufacturer for recycling. The
incinerator would be operated according to RCRA requirements.
The ash residue from incineration would be landfilled in a new
10-acre facility on-site and closed and capped according to RCRA.
Long-term monitoring and restrictions on the use of the property
would not be implemented, unless the ash cannot be delisted or
does not reach background contaminant concentrations. The
cleanup concentrations for soil excavation above the water table
would be the same as for Alternative 3b. In addition, the goal
of excavation beneath the water table would be to remove all
soils which are visibly contaminated or contain detectable high
molecular weight PAH compounds. Incineration would meet RCRA
Best Demonstrated Available Technology levels and would achieve a
destruction efficiency of 99.99%, in accordance with RCRA
requirements, in addition to reducing total carcinogenic PAH
concentrations to less than 36 mg/kg (Table 7). Institutional
controls designed to prevent the use of contaminated ground water
would be implemented in the contaminated area, until ground water
quality returned to acceptable levels.
Contingency Remedy B. If pilot testing indicates that
ground water remediation would only be practicable in the area of
the CERCLA lagoon, but would not be effective in the swamp area,
most probably due to lower permeability aquifer materials, the
swamp area soils will be excavated to a depth of approximately 20)
feet, in addition to the excavated areas outlined in modified
soil Alternative 3b. The swamp area excavation is expected to
45
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0100680
generate approximately 44,800 cubic yards of soil, in addition to
the 11,700 cubic yards from other areas at the Site. The
response objectives and cleanup levels would be the same as those
described under Contingency Remedy A. For the same reasons
outlined under Contingency Remedy A, the total of 53,500 cubic
yards of excavated contaminated soil would be incinerated on-
site, a process which would take approximately 2 years.
X. 'Statutory Determinations
Under its legal authorities, the EPA's primary
responsibility at Superfund sites is to undertake remedial
actions that are protective of human health and the environment.
In addition, Section 121 of CERCLA establishes several other
statutory requirements and preferences. Specifically, when
complete, the selected remedial action must comply with
applicable or relevant and appropriate standards established
under Federal and State environmental laws unless a statutory
waiver is granted. The selected remedy must be cost-effective
and utilize permanent treatment technologies or resource recovery
technologies to the maximum extent practicable. Finally, the
statute includes a preference for remedies that permanently and
significantly reduce the volume, toxicity or mobility of
hazardous wastes. The following sections discuss the selected
and contingency remedies for the Site in light of these statutory
requirements.
Protection of Human Health and the Environment
The soil component of the selected remedy (excavation and
on-site biological treatment) protects human health and the
environment through removal and treatment of soils. Biological
treatment will be conducted in accordance with RCRA requirements
which will ensure that the treatment operation is protective.
This remedy will eliminate the direct contact threat currently
present and will minimize future effects on ground water and
surface water by removing the sources of waste above the water
table. The cancer risks associated with source areas will be
reduced from the present level of greater than one in ten
thousand (1 x 10"^) to a level of one in one hundred thousand (1
x 10~5) or better. Excavated soils will be treated to a risk
level of better than one in ten thousand (1x10~^). These
levels are within the acceptable range. Short-term risks
associated with this remedy, such as air releases during
excavation, can be controlled. Although contaminated beach
sediments will not be excavated, these sediments are covered with
two feet of clean sand, preventing direct contact. Excavation of
these sediments was determined to pose a risk to the water
quality of Flathead Lake which was greater than the risk of
leaving them in place. The beach sediments will be reevaluated
every five years to ensure that no further action is necessary.
46
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0100681
The selected ground water alternative (hot water flushing,
surface chemical treatment, and in-situ biological treatment)
also protects human health and the environment by treatment of
ground water to acceptable levels. This remedy will eliminate
both the potential for risk to human health from consumption of
contaminated ground water and the impact to the environment from
the discharge of contaminated ground water to surface water. The
cancer risks posed by ingestion of contaminated ground water will
be reduced from at most one in ten thousand (1 x 10"^) to one in
one hundred thousand (1 x 10~5) or lower. There are no short-
term risks associated with this remedy which will not be
controlled.
Each of the contingency remedies protects human health and
the environment by excavating and destroying contaminants in
soils through thermal treatment. Some short-term adverse effects
may occur during a deep excavation in the swamp, but these risks
will be greatly reduced through proper engineering controls or
design features. If the selected remedy component for ground
water proves not to be practicable, institutional controls will
be implemented, in addition to excavation of source soils, in- an
effort to prevent access to contaminated ground water until
natural degradation has reduced residual contamination to
acceptable levels. Implementation of such institutional controls
will meet the protection standards set by Section 121 of CERCLA
in conjunction with other contingency soil remedies.
Attainment of Applicable or Relevant and Appropriate
Requirements
The selected remedy for both soil and ground water cleanup
will meet all applicable or relevant and appropriate requirements
(ARARs). Contingency remedy A may temporarily violate the State
of Montana nondegradation requirements during the time that the
ground water contaminant plume downgradient of the CERCLA lagoon
excavation is undergoing natural degradation, since there may be
some expansion of the plume during this time. However, this
requirement will not be met only if it is found to be technically
impracticable to remediate the aquifer. Otherwise, the
contingency remedies will meet all applicable or relevant and
appropriate requirements. Attachment A lists the ARARs
identified for the selected and contingency remedies.
Cost-Effectiveness
The selected remedy is cost effective because it has been
determined to provide overall effectiveness proportional to its
costs, the net present worth value being approximately
$11,000,000. The selected remedy effectively and permanently
reduces contamination in both media to acceptable levels and
provides a level of protection equal to or exceeding that of thel
other alternatives. Incineration rather than land treatment of
47
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0100632
the same soil volume would be over three times as expensive while
providing a similar degree of protection. Containment of
contaminated soils would be less expensive but would not reduce
toxicity, mobility or volume through treatment.
If ground water remediation is found to be impracticable in
the CERCLA lagoon and/or the swamp pond area, the contingency
alternatives involving deep excavation and on-site incineration
of soils are the next most cost-effective solutions. Although
incineration would be the most costly option to treat the large
volume of soils which would be excavated, incineration would
achieve treatment goals in a much shorter time (two years, as
compared to 30 to 50 years for land treatment of the same
volume), requiring a much shorter period of operation and
management of the treatment unit. Therefore, the overall cost
effectiveness of incineration is deemed to be greater than land
treatment for the volume of soils to be treated. The present
worth cost of incineration would be within an order of magnitude
of the cost of land treatment.
The EPA has determined that the selected and contingency
remedies are cost-effective, based on the fact that the cost is
proportional when considering the risk reduction being achieved
and the short-term effectiveness of the remedies.
Utilization of Permanent Solutions and Alternative Treatment
or Resource Recovery Technologies to the Maximum Extent
Practicable
The alternatives were analyzed to determine which would
utilize treatment technologies to the maximum extent practicable
to achieve the response objectives of controlling direct contact
exposure to soils, minimizing the impact to ground water from
soil contamination, preventing ingestion of unacceptable
concentrations of contaminants in ground water, and minimizing
the impact to surface water from ground water contamination. By
employing land treatment or incineration to reduce the
contaminant concentration in soils and by using chemical and
biological treatment to reduce concentrations in ground water,
the selected and contingency remedies use permanent treatment
technologies to the maximum extent practicable for the Site.
Containment without treatment may afford greater levels of short-
term effectiveness for soil, but it does not outweigh the need
for long-term effectiveness afforded by treatment.
Protection of ground water will be achieved by utilizing
alternative technologies to remediate the aquifer. Hot water
flushing or in-situ bioremediation of ground water alone would
take five to ten years longer to achieve cleanup goals than the
preferred remedy which combines aspects of each. If ground water
remediation is not practicable, then institutional controls
designed to prevent usage of contaminated water will be
48
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010063
implemented, in addition to excavation of source material, untiflH
natural processes return contaminant concentrations to acceptable
levels.
Preference for Treatment as a Principal Element
By biologically treating contaminated soils and chemically
and biologically treating contaminated ground water, the selected
remedy addresses the principal threats at the Site through the
use of treatment technologies. Therefore, the statutory
preference for remedies that employ treatment as a principal
element is satisfied. If ground water remediation cannot be
achieved due to technological limitations, then a contingency
remedy involving incineration of contaminated soils both above
and below the water table, will be implemented, also addressing
the statutory preference for treatment. If ground water
remediation is impracticable, the statutory preference for
treatment of contaminated ground water downgradient from the
CERCLA lagoon could not be met, to the extent that contaminated
ground water must be left in place.
XI. Documentation of Significant Changes
a) The Proposed Plan was released for public comment in May
1989. The Proposed Plan identified Soil Alternative 3c,
excavation and off-site land treatment at BN's Paradise, Montana
facility, as the preferred soil component of the cleanup
alternative. One of the other soil alternatives (Alternative 3b)
presented in the Proposed Plan and the FS involved excavation of
the same areas and volumes of soil with biological treatment on-
site. The original preference for Alternative 3c was based on
the following considerations: 1) space was available off-site to
begin treatment of all the soils almost immediately after
excavation, 2) the off-site treatment unit was located on
agricultural land providing a visual and noise buffer zone
between the unit and local residences, and 3) the similarity in
contaminated soils from Somers and Paradise and BN ownership of
both facilities would allow for a coordinated approach to cleanup
of both sites.
During the comment period, EPA and the State of Montana
received considerable public comment in opposition to off-site
treatment of Somers soils at Paradise. The State of Montana
requested EPA to reconsider its preference for this alternative.
As a result, EPA extended the comment period on the Proposed Plan
and again asked the public to comment on all soil cleanup
alternatives, including on-site biological treatment. A second
public meeting was also held in Somers.
The EPA, in consultation with the Montana Department of
Health and Environmental Sciences, decided to select the on-site
biological treatment remedy for soils (modified Alternative 3b>
49
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010063>;
in addition to ground water Alternative 6. Although Alternative
3b included excavation of contaminated beach sediments, these
have not been included in the selected alternative because of
concerns about possible adverse impacts to Flathead Lake
resulting from such an excavation. The public was given the
opportunity to comment on an alternative involving no excavation
of beach sediments (Alternative 3a). Rather than select
Alternative 3a, which did not provide for excavation of
contaminated sediments in the slough, EPA decided to modify
Alternative 3b.
b) The EPA proposed plan recommended that land treatment, if
conducted on-site, continue until the total carcinogenic PAH
concentration was reduced to below 36 mg/kg and RCRA Best
Demonstrated Available Technology concentrations were achieved.
This Record of Decision more clearly defines the treatment levels
to be achieved in the land treatment unit. The Record of
Decision requires that once initial health-based levels and RCRA
Best Demonstrated Available Technology concentrations have been
met, treatment will continue until the decrease in total PAH ,has
been less than 20% from the previous year. The initial health-
based level to be achieved provides for a reduction in
carcinogenic risk to a one in ten thousand (1 x 10~4) level,
which is at the upper end of EPA's acceptable risk range.
Additional treatment would reduce residual concentrations to a
level closer to EPA's goal of one in one million (1 x 10~6). If
treatment results in leachate concentrations within health-based
levels, the land treatment unit can be closed with a vegetative,
rather than an impermeable cap, allowing for a broader range of
future uses of the property. EPA recognizes, however, that it
may not be possible to reduce residual carcinogenic PAH
concentrations much below the initial level of 36 mg/kg.
Therefore, if, after treating for another year, the total PAH
concentration is not reduced at least 20% over the previous year,
another soil application may be made or the unit may be closed.
c) Finally, EPA's proposed plan contained two contingency
remedies in the event that ground water remediation proved to be
impracticable at the Site. The first contingency remedy would be
implemented if ground water cleanup is found to be impracticable
in both the CERCLA lagoon and swamp areas. Under this
contingency, the proposed plan recommended incineration of the
excavated soils. Consistent with the proposed plan, Contingency
Remedy A in this Record of Decision retains incineration as the
treatment technology. However, Contingency Remedy B, in which
deep excavation will be implemented only in the swamp area if
ground water remediation is found to be impracticable there, has
been changed in the Record of Decision from that recommended in
the proposed plan. Instead of land treating the excavated soils
both at the BN Paradise facility and on-site, as recommended in
the proposed plan, the Record of Decision calls for incineration
of these soils.
50
-------
0100635
EPA's decision to change the treatment technology ^nder
Contingency Remedy B stems from the change in treatment location
under the selected alternative from land treatment of soils at
Paradise to land treatment on-site at Somers. Since the Paradise
facility will not be used to treat any of the Somers soils, all
of the excavated soils must be treated on-site. Because of the
proximity of the available treatment area to local houses, the
treatment unit will be restricted to a size of 10 acres in order
to provide a visual and noise buffer zone between the unit and
the houses. The volume of soils which would be excavated under
this contingency remedy would require 30 years or more to treat
using a land treatment process versus two years to incinerate.
During the treatment period, both a temporary storage unit and
the treatment unit must be managed to prevent migration of
hazardous wastes into the environment. Both units would be
lined, however the reliability of a liner would tend to decrease
with use over time. For these reasons, and because treatment
levels would be achieved in two years as opposed to 30, EPA
decided to select incineration as the treatment method under
Contingency Remedy B.
From among the protective, ARAR-compliant, and cost-
effective remedies, the EPA, in consultation with the State,
determined that the selected remedy provides the best balance
with respect to long-term effectiveness, reduction in toxicity,
mobility, and volume afforded through treatment, short-term
effectiveness, and implementability and cost, while also weighing
the statutory preference for treatment as a principal element and
giving consideration to community and State acceptance. On-site
biological treatment will provide a comparable level of
protection to the off-site treatment remedy originally preferred.
If the selected ground water remedy cannot be implemented, the
contingency alternatives provide the next best balance among the
evaluation criteria.
51
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0100636
BIBLIOGRAPHY
Bowers, J.F., J.R. Bjorklund, and C.S. Cheney (1979)
Industrial Source Complex Dispersion Model User's Guide.
Prepared for U.S. .EPA by H.E. Cramer Co., Inc., Salt Lake City,
UT. EPA-450/4-79-030.
Cowherd, C., G.E. Muleski, P.J. Englehart, and D.A. Gillette
(1984) Rapid Assessment of Exposure to Particulate Emissions from
Surface Contamination Sites, Midwest Research Institute, Kansas
City, KS.
Horst, T.W. (1979) Lagrangian Similarity Modeling of
Vertical Diffusion from a Ground Level Source, Int. Applied Met.,
18: 733-740.
Montana Department of Health and Environmental Sciences
(1989) Burlington Northern Railroad Paradise Tie Treating Plant
Land Treatment Unit, Permit No. MTHWP-88-03, Modification No. '1.
Noble, R.A. and J.A. Stanford (1986) Ground water Resources
and Water Quality of the Unconfined Aquifers in the Kalispell
Valley, Montana. Montana Bureau of Mines and Geology Open-File
Report 177.
Pasquill, F. (1975) The Dispersion of Material in the
Atmospheric Boundary Layer — the Basis for Generalization, In:
Lectures on Air Pollution and Environmental Impact Analysis,
American Met. Soc., Boston, MA.
Remediation Technologies (1987) RCRA Part B Permit
Application, Paradise Land Treatment Facility.
Remediation Technologies (1989) Remedial Investigation and
Feasibility Study for the Somers Tie Plant, Volumes I-V.
Umbreit, T.H., Hesse, E.T., Gallo, M.A. (1986)
Bioavailability of Dioxi'n in Soil from a 2,4,5-T Manufacturing
Site, Science 232:497-499.
U.S. EPA (1985a) Administrative Order on Consent, Docket No.
CERCLA VIII-85-02.
U.S. EPA (1985b) Administrative Order on Consent, Docket No.
CERCLA-VIII-85-07.
U.S. EPA (1986a) Superfund Public Health Evaluation Manual,
EPA 5401-1/86/060, Office of Emergency and Remedial Response.
"U.S. EPA (1986b) Quality Criteria for Water, EPA 440/5-86-
001(51 FR 43665) .
52
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0100637
U.S. EPA (1988) Guidance for Conducting Remedial
Investigations and Feasibility Studies Under CERCLA, EPA 540/G-
89/004, OSWER Directive 9355.3-01.
U.S. EPA (1989) Interim Final Guidance for Soil Ingestion
Rates, OSWER Directive 9850.4.
53
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ATTACHMENT A
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
SOIL ALTERNATIVES
STATUTE.OR
KBEHT-ATIQM/CITATICIN
APPLICABLE OR
RELEVANT J.
APPROPRIATE COMENTS
FEDERAL REQUIREMENTS
l/vatlnn-Spepiflc:
txecutlve Order 11990
',0 Code of Federal
Regulations (CFR)
I'art 6
lixecutlve Order 11988
40 CFR Part 6
Kloodplaln Management
40 CFR Part 6
App. A
Fish and Wildlife
Coordination Act
16 United States
Code (USC) 661 et seq.
11uj.uttered Species Act
.u CKK I'arti 2()0
Protection of wetlands during beach, swamp and slough excavation-
Floodplain management during excavation of beach, swamp and slough-
Activities must not affect or be affected by presence of a floodplain-
Habitat of local or migratory endangered species (peregrine falcon and bald eagle) must be
preserved during site activities-
CD
^-»
O
CO
00
-------
Resource Conservation &
Recovery Act
40 CFR Part 264,
Subpart B
National Historic Preserva-
tion Act, Section 106,
16 U.S-C. 470 et seq-,
36 CFR Part 800-
Art)on-Spenlfir:
Location standards for construction of land treatment unit, waste pile or Incinerator-
Resource Conservation
Recovery Act
40 CFR Part 264 ,
Subpart C
Subpart D
Subpart F
Subpart G
Subpart J
Subpart L
Subpart M
Subpart N '
Subpart 0
<,0 CFR Part 268
Subparts A.
D i. RCRA Sec
Tie plant buildings proposed for demolition are eligible for National Register of Historic
places; mitigation must be provided-
A Preparedness and prevention requirements-
A Contingency plans and emergency procedures-
A Ground water monitoring and corrective action requirements In the event of ground water
contamination from treatment, disposal or temporary storage unit-
A Closure and post-closure requirements for treatment, disposal or temporary storage unit-
A Requirements for tank systems may be Imposed If excavated soils are stored In tanks
while awaiting treatment.
A Requirements for construction, operation, and closure of a temporary storage unit.
A Requirements for construction, operation, and closure of a land treatment unit-
A Requirements for construction, operation and closure of a landfill for disposal
of Incinerator ash-
A Requirements for construction, operation and closure of an Incinerator-
A Placement of hazardous waste In temporary storage, land treatment or disposal unit or landfill Is
subject to land disposal restrictions-
-------
51 FR 25760
42 U-S.C. 6924(d)(3)
Occupational Safety and
Health Act
29 CFR 1926, Subpart
P, and 1910
40 CFR Part 262,
Subparts B.C.D
A
A
Best Demonstrated Available Technology standards must be met prior.to placement of RCRA hazardous
waste In a land disposal unit. Applies to placement of Incinerator ash In a landfill or soils
In a land treatment unit, unless a no-migration demonstration Is made-
Worker safety-
STATE REQUIREMENTS
fhpmlPA)-Sppp < f 1 r ;
Ambient Air Quality:
Administrative Rules of
Montana (ARM) 821, 925, 926
Control of emissions during soil excavation and treatment.
ARM 16.8.1402, 1404,
1406
ARM 16-8-1403
Irtratlrm-Speclf \r.:
Historic Preservation
Montana Code Annotated
(MCA) 22-3-432, 433
ARM 12.8-501, 505-508
Floodplaln & Floodway Management
MCA 76-5-102
R&A
R&A
A
A
Sets emission standards for an Incinerator-
Restricts paniculate emissions from Industrial processes; R&A to Incinerator-
Applies to State-owned lands- Tie plant buildings are eligible for the National Register;
mitigation must be undertaken when they are demolished -
Excavation and construction activities In the swamp, slough and beach areas must not adversely
affect the floodplaln or Its uses and must withstand flooding-
-------
MCA 76-5-401, 402, 403,
404, 405, 406
ARM 36.15-204, 216
ARM 36.15.501
ARM 36.15-603-606
ARM 36.15-701, 703
Endangered Species
MCA 87-5-103, 107
MCA 87-5-501
ARM 12.5-201
Natural Streambed & Land
Preservation
MCA 75-7-208
Hazardous Waste Management
ARM 16.44-702
ApyIon-SpecIfIP:
Occupational Safety and
Health Administration
MCA 50-70-113
ARM 16.42-101, 102
Ambient Air Quality
MCA 75-2-102
MCA 75-2-201T
A
A
A
A
A
A
A
R&A
A
A
A
A
Bald eagle and peregrine falcon habitats must be protected.
No streams affected but protection must be provided to Flathead lakeshore during excavation
In the beach or swamp areas-
Prohibits siting hazardous waste treatment, storage or disposal facility within a floodplaln or
near an active fault.
Worker safety requirements-
Noise and air emissions limitations to protect workers-
Requirements for monitoring and limiting air emissions during soil excavation and
treatment-
-------
ARM 16.8-704
ARM 16.8-804, 807-
809, 811, 822
ARM 16.8-922, 923,
927, 931, 932, 938
ARM 16-8.929, 930, 933
ARM 16.8-932,
935
ARM 16-8.1003
ARM 16.8-1004
ARM 16.8.1007
ARM 16.8.1102-1105,
1109
ARM 16-8.1302
ARM 16-8.1401,
1411, 1423,
1424, 1425, 1427
Solid Waste Management
MCA 75-10-212,
214, 221
ARM 16.14-505. 508,
509. 521. 523
Hazardous Waste Management
MCA 75-10-406
A
A
R&A
A
R&A
A
RM
A
A
Applies to major stationary sources; relevant and appropriate for operation of an Incinerator.
Impact analysis required for air emissions source-
Applies to Federal Class I area-
Visibility models prescribed for Impact assessment.
Preconstruction visibility monitoring required In Federal Class I area; relevant and appropriate
for operation of an Incinerator at the Site-
Emissions controls required for a treatment unit.
Open burning prohibition-
Emissions standards for a treatment unit-
Solid waste generated during various site activities Is subject to various disposal, siting and
management requirements*
Requirements for management of hazardous waste excavated and treated In
a biological or thermal treatment unit or stored or disposed of on site- Includes monitoring
requirements-
-------
ARM 16.4Ji.102, 106, A " "
109, 110, 113, 120,
123
ARM 16.44.124 A Requirements for conducting a land treatment demonstration.
ARM 16-44.303, 310, 311, A Identification and listing of hazardous wastes.
321, 322, 323, 324, 333
ARM 16-44-401-417 A Generator requirements; hazardous waste will be generated by excavation of contaminated
materials-
Public Water Supply
MCA 75-6-101 A Protection of water/sewer lines during excavation-
ARM 16-20.402 A
Section 121 of SARA exempts on-slte CERCLA activities from obtaining permits- However, the substantive requirements of listed laws or
regulations must be met-
Administrative or procedural requirements of listed State laws and regulations are not considered as ARARs, however, the substantive provisions
of these requirements are ARAR-
-------
GROUND WATER ALTERNATIVES
STATUTE OR
REGULATION/CITATION
APPLICABLE OR
RELEVANT fc.
APPROPRIATE CCWBTTS
FEDERAL REQUIREMENTS
Phgml rn 1 -Spec 1 f 1 p. ;
Safe Drinking Mater Act
AO CFR Part 141
Inrattrm-Speclf ic:
Executive Order 11990
i»0 CFR Part 6
Executive Order 11988,
40 CFR Part 6
Endangered Species Act
50 CFR Parts 200
and 402
Fish and Wildlife
Coordination Act
16 USC 661 et seq.
Resource Conservation
and Recovery Act
40 CFR Part 264
Subpart B
Af llnn-Speclf lc:
Pretreatment
40 CFR Part 403-5
R&A Maximum Contaminant Levels are treatment concentrations for ground water-
Protection of wetlands during construction and operation of ground water treatment unit.
Floodplaln management during operation of ground water treatment unit- Activities must not
affect or be affected by presence of a floodplaln.
Habitat of local or migratory endangered species (bald eagle and peregrine falcon) must be
preserved during site activities-
Location standards for construction of ground water treatment unit.
C".
CO
Requirements for Indirect discharge of treated ground water to a POTW.
-------
iafe Drinking Water Act
')0 CFR Part 144,
lUbparts A, B, C,
£, Part 146, Subparts
\ L B, Part 147,
Subpart BB
Occupational Safety and
Health Act
29 CFR 1926 Subpart
P and 1910
Resource Conservation and
Recovery Act
40 CFR Part 264
Subpart C
Subpart D
Subpart F
Subpart C
Subpart I
Subpart J
40 CFR Part 268
Subparts B, C, D fi> E-
RCRA Section 3004(d)(3)
Requirements for reinjectIon of treated ground water-
51 FR 40641
51 FR 25760
42 U.S-C. 6924<)(e)(3)
<<^))(
A
A
A
A
A
A
A
A
A
A
Worker safety.
Preparedness and prevention requirements.
Requirements for a contingency plan and emergency procedures-
Ground water monitoring and corrective action requirements In the event of ground water
contamination from ground water treatment operation-
Closure and post-closure requirements for ground water treatment unit.
Container storage requirements apply to storage of contaminated ground water for treatment-
Requirements for tank systems used during ground water treatment-
ReInjectIon of treated ground water may be subject to land disposal restrictions-
Best Demonstrated Available
wastes prior to disposal-
logy standards would apply to treatment of hazardous
-------
40 CFR Part 270
Subpart F
Requirements for sending treated ground water to a POTW or reinjectIng.
STATE REQUIREMENTS
fhpmlral-Span1f io:
NondegradatIon
MCA 75-5-303
ARM 16.20-702, 703
Public Water Supplies
ARM 16.20-203, 205
Surface Water Quality
ARM 16.20-617
Montana Ground Water
Pollution Control
ARM 16.20.1003, 1011
A Prohibits degradation of ground water or Flathead Lake during cleanup activities-
A Discharge limits would apply to reinjectIon of treated water-
A Maximum Contaminant Levels are treatment concentrations for ground water.
A Water Quality Standards are treatment concentrations for ground water.
Degradation prohibited during reinjectIon of treated ground water-
I/vat Ion-Sped f Ir:
Endangered Species
MCA 87-5-103, 107
MCA 87-5-501
ARM 12.5-201
Floodplaln f. Floodway
MCA 76-5-102
MCA 76-5-202
MCA 76-5-401, 402,
i.ru,. tns.
A
A
A
A
A
Bald eagle and peregrine falcon habitats must be protected-
Ground water treatment activities must not adversely affect the floodplaln or
its uses and must be constructed to withstand flooding-
-------
ARM 36.15.204, 216
ARM 36.15-501
ARM 36-15.603-606
ARM 36.15.701, 703
Hazardous Waste Management
ARM 16.44.702
Artlrm-Spgplf In
Occupational Safety and
Health
MCA 50-70-113
ARM 16-42.101, 102
Public Mater Supplies
MCA 75-6-101, 105
112
ARM 16-20.213
Surface Water Quality
ARM 16.20.602,
605. 631,
633, 635
ARM 16.20.632
Water Quality Act
MCA 75-5-101
MCA 75-5-602, 605
A
A
A
A
R&A
A
A
Prohibits siting ground water treatment facility within a floodplaln or near an active
fault-
A Worker safety requirements-
A Noise and air emissions limitations to protect workers-
Ground water treatment operation must not adversely affect municipal water supply-
Ground water cleanup standards and sampling methods required during ground water treatment
operations.
Operating standards for facilities operating prior to July 1971; relevant and appropriate to
ground water treatment operations at the Site-
Policy statement.
Monitoring requirements for discharge of treated water to POTW.
-------
Surface & Groundwater
Appropriations
MCA 85-2-505
Montana Pollution Discharge
Elimination System
ARM 16.20.907, 916
Hazardous Waste Management
Act
ARM 16.44.102, 109, 110, 120
ARM 16-44.310, 311, 321-324,
333
ARM 16.44-401-417
Water Well Construction
MCA 37-43-105
MCA 37-43-101, 104
MCA 37-43-202
ARM 36-21.638, 640-
662, 664, 666-679
Montana Ground Water
Pollution Control
ARM 16.20.1002,
1010, 1013, 1015,
1016
A Prohibition on wasting ground water during ground water treatment operations-
A Prohibition on the use of public water wells for injecting contaminated ground water.
A Construction, operation and monitoring requirements for ground water treatment unit.
A Identification and listing of hazardous wastes.
A Generator requirements would apply to handling of spent carbon used to treat ground water-
A
RbA
R&A
R&A
Policy Statement.
Water supply wells for drinking water will not be constructed, but construction requirements R&A
are relevant and appropriate to wells used In ground water treatment-
Regulations on discharge of pollutants to ground water apply to reinject Ion of treated water-
Section 121 of SARA exempts oil-site CDC LA activities from obtaining penults- However, the substantive requirements of listed laws or
regulations must be met -
Administrative or procedural requirements of listed State laws and regulations are not considered as ARARs, however> the substantive provisions
-------
of these requirements are ARAR-
-------
ATTACHMENT B.
BURLINGTON NORTHERN (SOMERS PLANT) SUPERFUND SITE
FLATHEAD COUNTY, MONTANA
RESPONSIVENESS SUMMARY
A. OVERVIEW '
The preferred alternative for remediation of the Burlington
Northern Somers Site, recommended by EPA in the proposed plan,
addressed the soil and ground water contamination problems at the
site. The preferred alternative involved a) excavation and land
treatment of soils at a Burlington Northern facility in Paradise,
Montana, and b) hot water flushing with chemical treatment and
in-situ bioremediation of ground water. EPA also proposed
contingency alternatives in the event that ground water treatment
proves to be impracticable at the site and source area soils must
be excavated to depths significantly below the water table. '• In
this event, depending on the extra volume of soils excavated, EPA
proposed to either land treat the soils both on-site and off-site
or, if the soil volume is very large, to incinerate the soils on
site.
Judging from the comments received during the public comment
period on the proposed plan, Paradise residents would strongly
object to any alternative which would bring contaminated soils
from Somers to Paradise for treatment. The Montana Department of
Health and Environmental Sciences (MDHES), after receiving
significant public comment against such an alternative, requested
that EPA reconsider its preference for treatment of soils at
Paradise. Comments received from residents of Somers and nearby
communities as well as local environmental groups indicated
support for the concerns of the community of Paradise and general
acceptance of on-site biological treatment of soils using a land
treatment process. Commentors also expressed support for the
proposed ground water treatment method, but were concerned that
adequate pilot testing be done to assure that excess nutrients
from the in-situ treatment system are controlled. The Flathead
Lake Protection Association (FLPA), which has an EPA technical
assistance grant, and Burlington Northern Railroad (BN) both
opposed the contingency alternative involving on-site
incineration. MDHES expressed a preference for incineration
under either contingency alternative. The FLPA and many other
commentors requested that contaminated beach sediments be left in
place due to concerns about a possible release of contaminants to
Flathead Lake during excavation.
The responsiveness summary consists of the following
sections:
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o Background on Community Involvement
o Summary of Comments Received during the Public Comment
Period and Agency Responses.
o Remaining Concerns.
' o Summary of Community Relations Activities at the BN
Somers Site.
B. BACKGROUND ON COMMUNITY INVOLVEMENT
Community interest in the Somers Site has involved both
local residents and public interest groups active in issues
affecting the greater Flathead valley. Somers residents have
been particularly concerned about local public health issues and
the potential impact of contamination on their drinking water
supply while valley-wide interest has been focused primarily on
the potential impacts of the Site on Flathead Lake. Additional
concerns include the effects of the Site on local property
values, possible future limitations on the use of the Site
property for development, and access to the local beach area for
recreational use.
The EPA approved a Technical Assistance Grant for the
Flathead Lake Protection Association in January, 1989. The
Association has participated in reviewing and interpreting Site
technical reports and other documents and has provided
information to the community and comments to EPA on the RI/FS and
proposed plan for Site cleanup. Another environmental group, the
Clark Fork Coalition, became involved in the Site because of the
EPA proposal to treat Somers soils at the BN Paradise facility
which is located on the Clark Fork River.
During the 1985 comment period on the Administrative Order
and Work Plan for the RI/FS, EPA received a number of comments,
questions and concerns. Some of the major issues raised and how
EPA and the State addressed them are described below:
o A number of commentors expressed concern that EPA
oversight procedures would be inadequate and that the
public would not be. kept informed.
EPA Response: EPA responded that it would use a number
of methods to keep the public informed, including
periodic public meetings, public comment periods on
important documents such as the work plan, publishing
regular fact sheet updates, and establishing a fil
site material at the Somers School. All of these
activities were undertaken.
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EPA also indicated that the agency would oversee BN's
field activities and would split 10 to 25 percent of
the samples collected during the Remedial
Investigation/Feasibility Study (RI/FS). Split
sampling was routinely conducted during the RI/FS.
o Several commentors expressed concerns about the content
of the Administrative Order (AO), the procedures for
changing it and the need for additional studies that
might be required under it. EPA was requested to allow
the public to review any proposed changes to the AO in
advance.
EPA Response: EPA responded that if any changes were
proposed to the AO, EPA would make them available to
the public for review. As a result of public comments
received on the work plan which accompanied the AO, EPA
did decide to conduct additional sampling (see next
item) and the modification to the work plan was made
available to the public for a two week comment period.
o EPA was requested to conduct additional sampling in the
slough area and the Waterfowl Production Area (WPA)
near the Somers tie plant.
EPA Response: EPA, in consultation with the Montana
Department of Fish, Wildlife and Parks and the U.S.
Fish and Wildlife Service, decided that additional
investigations of the WPA and slough area were
necessary. Ultimately, sediments from these areas were
sampled, waterfowl observations in the slough area were
undertaken and waterfowl sampling was conducted.
During the progress of the RI/FS, EPA received a number of
significant comments which are summarized below.
o A former tie plant employee alleged that BN had dumped
zinc treated ties in a Somers landfill and that zinc
from the buried ties had migrated to a nearby drinking
water well.
EPA Response: EPA and MDHES sampled drinking water
wells located downgradient from the landfill and tested
the samples for metals. The levels of metals found
were well below the maximum levels EPA allows in
drinking water.
o Local residents expressed concerns that additional
investigations were necessary to evaluate any hazards
to private water wells located across the slough from
the tie plant.
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EPA Response: Additional sediment and water samples
were taken from the slough and piezometers were
installed to better define the movement of water in the
vicinity of the slough. The results indicate that,
while it does contain patchy areas of contamination,
the slough is an area of discharge for the water table
aquifer which would tend to prevent contamination from
moving beyond the area to local wells.
Concerns were expressed about EPA's proposal in June of
1988 to remove the Somers site from the proposed
National Priorities List (NPL), .because of its status
as a Resource Conservation and Recovery Act-regulated
site. Commentors indicated a preference for retaining
the site on the NPL in order to continue the Superfund
process which allows for significant public
involvement. Specific concerns were expressed about
the potential loss of the Technical Assistance Grant to
the Flathead Lake Protection Association if NPL status
is not retained, since NPL status is a prerequisite for
the' availability of such a grant.
EPA Response: EPA decided to delay removal of the Site
from the NPL until negotiations with the potentially
responsible parties (PRPs) for the conduct of the
Remedial Design/Remedial Action (RD/RA) have been (
completed. If the PRPs enter into a consent decree
with EPA to conduct the work, the cleanup of the Site
will be handled under the oversight of the EPA
Superfund program. The Site would then be removed from
the NPL; however, it is possible that the PRPs would
agree to fund the Technical Assistance Grant through
the completion of the work. If the PRPs are unable or,
unwilling to clean up the Site, EPA can repropose and
finalize 'the Site on the NPL and then take action
itself.
EPA was informed of an oily seep which had appeared
near the lakeshore away from the tie plant site, but in
the vicinity of an old railroad line associated with an
abandoned sawmill. Although BN excavated the
contaminated area and removed the contaminated soils,
area residents were concerned that the problem could be
more widespread. Concerns were also expressed that the
oil might be the result of dumping of materials from
the tie plant. The location of the seep was near the
proposed location for a new municipal well for the town
of Somers. EPA was requested to include this area
within the Somers tie plant Superfund Site.
EPA Response: EPA contacted the State Water Quality
Bureau to inform them of the contaminated area and
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0100704
initiated the review process for the Site to be
considered for the NPL, or for State Superfund action.
The first activity which will be undertaken in this
process is a Preliminary Assessment. If this initial
evaluation indicates that the Site may have problems
significant enough to qualify it for Superfund action,
a Site Investigation will be conducted. Depending on
whether there is currently a release of contaminants or
the threat of a release, and depending on the severity
of the problem, the Site may be eligible for the NPL,
or it may be eligible for action under the State
Superfund program.
o The Somers Water District twice experienced water line
ruptures where the municipal water lines pass through
the Somers tie plant property. In each case, the
District, EPA and MDHES were concerned that water
carrying contamination might have backflowed from the
ruptured area into local homes.
EPA Response; Immediately after both water line
ruptures, EPA and MDHES sampled water from homes
located on the water line below the point of the
rupture. The Somers Water District directed affected
residents not to drink their water and BN provided
bottled water to these residents. The results of the
water analyses indicated that the water was safe to
drink, therefore the Water District lifted its
restrictions on use (except for an ongoing boil order
because of the possibility of giardia in the unfiltered
water supply).
C. SUMMARY OP COMMENTS RECEIVED DURING THE PUBLIC COMMENT PERIOD
Comments received during the BN Somers public comment period
on the draft FS and proposed plan are summarized briefly below.
The comment period was held from May 18, 1989 to August 3, 1989.
The comments are categorized by relevant topics.
Remedial Alternative Preferences
Each of the major commentors on the draft FS and proposed
plan expressed a preference for specific alternatives:
1. MDHES concurred with the soil alternatives evaluation in the
EPA proposed plan and with off-site treatment as an
acceptable alternative for soil remediation, but withheld
judgement on the selection of a treatment location pending
the evaluation of a RCRA permit application for the Paradise
facility. During the public comment period on the proposed
plan, the State received substantial comment in opposition
to transporting more soils from Somers to Paradise for
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0100705
treatment and MDHES requested EPA to reconsider its
preference for that alternative and to consider on-site
treatment or treatment at another off-site location. MDHES
concurred with the ground water alternatives evaluation and
with EPA's proposed plan for groundwater remediation, but
withheld judgement on the disposition of any additional
soils or sludges that might be generated if ground water
remediation proves to be impracticable. MDHES indicated a
preference for incineration of soils as the contingency
remedy if ground water remediation proves to be
impracticable.
EPA Response: EPA seriously considered the State's, as well
as the community's, preferences and has decided on the on-
site remedial action described in the Record of Decision
(ROD). This remedial action will involve excavation and on-
site biological treatment of soils by a land farming method.
The ground water remedial action will be the same as that
described in the proposed plan. However, if ground water
remediation is not practicable in the vicinity of the former
swamp pond or CERCLA lagoon, deep soils in these areas must
be excavated. All of the excavated soils will then be
incinerated on-site rather than land treated at both
Paradise and Somers as originally proposed.
The Flathead Lake Protection Association (FLPA), and over 50
commentors, supported on-site land treatment of soils, but
recommended that beach sediments not be included in the
areas of excavation and incineration not be considered as a
contingency alternative for soils. The commentors also
recommended that slough sediments and soils in a spur track
on the tie plant property be excavated and land treated.
The same commentors supported EPA's proposed plan for ground
water remediation with a pilot study and demonstration that
nutrients from the treatment area will not adversely affect
Flathead Lake.
EPA Response: As discussed in the response to comment tl
above, EPA has decided on the on-site remedial action
described in the ROD. After considering arguments presented
by the FLPA, and based on EPA's own analysis that excavation
of beach sediments may pose a greater environmental hazard
than leaving them in place, EPA decided to exclude the beach
sediments from those which will be excavated and treated.
However, the beach sediments will be reevaluated every five
years to ensure that no action is necessary in this area.
Further site sampling will be done during the design of the
remedial action to investigate whether the spur track soils
require remediation and to develop an estimate of the volumj
of these soils which might require excavation and treatment
EPA's original proposed plan for ground water remediation
called for pilot testing of the hot water flushing and in-
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0100706
situ bioremediation processes to determine their
practicability at the Site. A part of this study will
include a demonstration that the addition of nutrients will
not be harmful to Flathead Lake. For the reasons outlined
in this Record of Decision, EPA has retained incineration as
the contingency remedy if ground water remediation is not
practicable.
3. The ClarJc Fork Coalition, the Board of County Commissioners
of Sanders County, the Eastern Sanders Conservation
District, two-members of the Montana House of
Representatives and approximately 60 residents of the towns
of Paradise and Plains commented in opposition to EPA's
proposal to transport contaminated soils from Somers to
Paradise for treatment. The Governor of Montana and
Montana's representatives to the U.S. Senate and House of
Representatives were requested by an number of these
commentors to intercede on behalf of the community. In
general, the community of Paradise preferred to limit the
volume of contaminated soils in their vicinity because of
concerns about the proximity of the Paradise facility to the
Clark Fork River and fears that a failure of the land
treatment unit or waste storage pile might further
.contaminate the local aquifer or might eventually cause
contamination of the river.
A number of the Paradise residents expressed disbelief that
the land farming method would break down the creosote
contaminants in the soil. Some individuals indicated to EPA
that members of the community were considering violent
action if soils were transported to Paradise from Somers.
EPA Response: Considerable evidence exists that creosote
contaminants can safely and effectively be broken down using
land farming methods. A land treatment demonstration at the
BN Paradise facility provided additional evidence of the
reliability of this method. Although EPA recommended
treatment of Somers soils at Paradise because this
alternative provided the best balance among the criteria EPA
uses to evaluate potential cleanup methods, community
acceptance of the final alternative is also an important
consideration. EPA therefore reexamined the other soil
cleanup alternatives discussed in the proposed plan and
decided to select on-site treatment of soils.
4. Burlington Northern Railroad (BN) commented in support of
the EPA proposed plan for both soil and ground water
remediation and supported wetlands restoration/replacement
in areas damaged by contamination or remedial activities.
However, BN commented against incineration of soils if
ground water remediation is found not to be practicable and
source area soils in the CERCLA lagoon and swamp area must
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0100707
be excavated. The primary reason given for BN's opposition
to incineration is that the method is not as cost effective
as land farming. BN also commented that EPA's cleanup
concentrations for ground water were overly conservative.
EPA's Response: EPA agrees that cost effectiveness is an
important consideration in selecting a remedial alternative.
However, a significant factor in cost effectiveness involves
the short-term effectiveness of a remedy. The time period
necessary to treat the approximately 11,700 cubic yards of
soil'to be excavated under the selected alternative is 8 to
10 years. If deep excavation is required in the CERCLA
lagoon and swamp areas, the time required to store, manage,
and treat the soils could exceed 50 years using a 10 acre
treatment unit. Since the treatment area will be located in
the center of the town of Somers, a larger unit (which could
shorten the time required to treat) would not be acceptable.
Incineration could be completed within 2 years, providing
for a much shorter period in which hazardous wastes must be
managed, both in storage and treatment. EPA has decided,
that the contingency alternative for treatment of soils from
. deep excavation in the CERCLA lagoon and/or swamp areas will
be incineration.
Technical Questions/Concerns Regarding Remedial Alternatives
Soil Alternatives
1. A commentor asked why EPA was recommending land treatment
when the RCRA land disposal restrictions would ban it.
EPA Response: The land disposal restrictions which were
enacted as part of the 1984 Hazardous and Solid Waste
Amendments to the Resource Conservation and Recovery Act do
not ban the land disposal of hazardous waste, but rather
place certain restrictions on such disposal to ensure that
human health and the environment are protected. The statute
defines land disposal to include land treatment facilities.
Contaminated soils at the Somers Site are considered to be
hazardous wastes under the category K001, bottom sediment
sludge from the treatment of wastewaters from wood
preserving processes that use creosote. These soils, with
the exception of soils contaminated by drippage of ties are
subject to the land disposal restrictions. The effective
date of the restrictions for these soils is August 8, 1990.
In order to apply Somers contaminated soils to a land
treatment unit after August 8, 1990 in accordance with the
land disposal restrictions, the soils must first be treated.
to RCRA Best Demonstrated Available Technology standards or}
a variance to the treatment standard or treatment method
must be obtained, or a demonstration must be made that there
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will be no migration of hazardous constituents from the
treatment unit for as long as the waste remains hazardous.
As discussed in the EPA proposed plan for the Site, land
treatment will only occur after a demonstration of no-
migration is made.
2. A number of commentors questioned why EPA recommended the
•Burlington Northern Paradise facility as a treatment
location, rather than Somers or a remote, unpopulated off-
site location.
EPA Response: EPA initially recommended treating the Somers
soils at the BN Paradise facility for the following reasons:
1) BN was already in the process of establishing a land
treatment facility at Paradise to treat soils contaminated
by tie treating operations. The soils at both Somers and
Paradise were contaminated by creosote and both properties
are owned by BN. EPA preferred to approach the cleanup of
the two sites in a coordinated manner. A pilot
demonstration conducted at the Paradise facility showed that
land treatment under the area soil and climate conditions
effectively breaks down the creosote contaminants in soils.
and the State hazardous waste program review of BN's
demonstration and other information contained in the permit
application for the Paradise facility indicated that the
operation could be conducted at Paradise without adversely
affecting the environment.
2) Treatment could be completed more quickly at Paradise due
to the availability of sufficient acreage to apply all of
the Somers soils immediately after excavation. At Somers,
areas suitable for land treatment are limited. Treatment
would therefore have to be done in stages, with soils
awaiting treatment being stockpiled at the Site. Treatment
of all of the excavated soils would therefore take
approximately twice as long at Somers as at Paradise.
3) The Paradise facility includes agricultural land which is
located some distance away from local residences and which
could be used for land treatment. A visual and noise buffer
zone would therefore be provided between the town and the
treatment unit. At Somers, the tie plant is located in the
middle of the town. Because of space limitations at Somers,
very little visual or noise buffer zone would be provided.
The possibility of developing a third location for land
treatment, away from both Somers and Paradise, was also
considered. Such an option would delay initiation of
treatment of soils due to the need to obtain additional
land, conduct a land treatment demonstration, and obtain the
necessary State operating permit. In many cases, areas
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0100709
which are uninhabited have climate or soil conditions which
are not conducive to land treatment or the availability of
irrigation water is limited. It is also not unlikely that,
as was the case at Paradise, local residents would be
opposed to the establishment of a treatment unit for Somers
soils in their vicinity. In addition, this option would
involve the creation of yet a third site managing hazardous
waste. For all of these reasons, EPA did not select another
off-site location.
3. The FLPA commented that selection of a new off-site location
for treatment of soils (other than Paradise) would cause
further delays in site cleanup that are not warranted.
EPA Response: EPA agrees, for the reasons given above in
comment number two, that developing a new off-site location
would delay the cleanup of the Somers Site. For this, and
the other reasons provided above, EPA has selected on-site
land treatment as the cleanup option for soils.
4. A commentor asked for an estimate of the difference in time
for land treatment to be completed at Somers versus
elsewhere.
EPA Response: Based on the land treatment demonstration
conducted by BN at the Paradise facility, an individual
application of soil is expected to take four to five years
to degrade to acceptable levels. At Paradise, because all
of the Somers soils could be applied at once, the total
treatment time would have been four to five years. At
Somers, the soils will have to be treated in two
applications; therefore the total treatment time will be
eight to ten years. If another off-site location were used,
it would take three to four years to obtain the land,
conduct a demonstration and obtain a necessary operating
permit. The total time to complete treatment would depend
on the volume of soils which could be applied to the unit in
one application and the breakdown times under conditions in
that area.
5. The FLPA commented that soil excavation must be continued
until "clean" material is encountered based on sample data
obtained during excavation. The FLPA further recommended
that an on-site analytical laboratory be used to verify the
proper extent of excavation, followed by certified
laboratory verification. The FLPA requested that the
verification method be presented to the Association before
implementation.
EPA Response: EPA agrees that excavation must continue
• until analysis of residual soils indicates that cleanup
levels have been met. EPA also agrees that the use of an
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on-site analytical laboratory, followed by verification
analyses/ would decrease the turnaround time for sample
results. Such a laboratory would also be useful in
monitoring the effectiveness of soil and ground water
treatment methods. However, the method by which these
analyses are made will be determined during the Remedial
Design process. The verification method to be used would be
presented to the public for comment once draft project plans
are developed.
6. A commentor indicated that cleanup of swamp pond sediments
was sloppily attempted several years ago and additional
removal and treatment is necessary in this area.
EPA Response: In the 1985 Emergency Removal, the heaviest
contaminated soil and surface water were removed from the
swamp and replaced with clean fill and rip rap was placed
along the lakeshore. This interim action was not intended
to be a final remedy for the area but was rather intended to
stabilize the shoreline to reduce the chances of a washout
of contaminated material into Flathead Lake. EPA agrees
that additional treatment is necessary, but has selected a
ground water treatment method to accomplish this goal rather
than additional excavation of soils. However, if pilot
testing shows that ground water treatment would not be
practicable in this area, EPA has proposed a contingency
remedy which would involve excavating and treating the
contaminated soils.
7. The FLPA and over 50 commentors recommended that beach
sediments be left in place because it would be very
difficult to control leakage within the contaminated
sediments during excavation leading to the possibility of
creating a greater environmental hazard than that presented
by leaving the sediments in place.
EPA Response: As noted in the proposed plan, EPA recognized
the difficulty of a beach excavation and the possibility of
an escape of contaminants to the lake during excavation, but
felt that engineering controls could be used to reduce this
effect. However, based on public concerns about the
possibility of increased environmental degradation and EPA's
own analysis of the risks and engineering practicability,
EPA has decided to leave the beach sediments in place. The
concentrations of creosote contaminants detected in Flathead
Lake water have been very low and typical of background
concentrations in surface water. EPA does not therefore
believe that contaminated beach sediments are currently
impacting the quality of lake water to an extent which would
necessarily require remediation. These sediments are
presently covered with clean beach sands and are therefore
unavailable for direct contact. However, because
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contaminated sediments will be left in place, EPA will
review this decision every five years. If at a future date
the contaminated sediments appear to be causing an
unacceptable impact to human health or the environment,
action may be taken to remediate the situation.
80 A commentor suggested that contaminated soils should be
stockpiled as soon as possible to prevent additional
contaminants from entering the ground water.
EPA Response: EPA agrees that soils which are adversely
affecting ground water should be excavated as soon as
possible. However, some areas of soil contamination at the
Site are not associated with contaminants in ground water
and may not require immediate excavation. For these areas,
it may be preferable to leave the soils in place to await
treatment, rather than excavating and stockpiling them. The
decision on what soils will be excavated and stockpiled will
be made during the Remedial Design process.
9. One commentor suggested excavating and storing the soils at
the Somers site while looking for another off-site treatment
location.
EPA Response: For the reasons given in the response to
comment number two, EPA is not looking for another off-site
treatment location.
10. A commentor asked EPA to describe how the soils would be
excavated.
EPA Response: Soils above the water table will be excavated
using standard construction methods. The fiber optic line
and water line in the vicinity of the CERCLA lagoon must be
taken into consideration. Saturated soils and sediments,
such as those in the slough or below the water table, would
be excavated using sheet piling to prevent caving.
Dewatering would be necessary, as well as temporary storage
and final treatment of the produced water. If swamp area
soils must be excavated, a coffer dam may be necessary to
prevent a blowout due to pressure from Flathead Lake.
11. A commentor asked where the excavated soils would be
stockpiled on site.
EPA Response: Excavated soils which are not immediately
applied to the land treatment unit will be placed in a lined
temporary storage unit within the tie plant property. The
storage unit will be placed as far from local houses as
possible.
\
12. A commentor asked what material would be used to backfill
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the excavated areas at Somers, where it would be obtained
and how it would be transported to Somers.
EPA Response: Clean soil will be obtained off-site and
transported to the Site by truck.
13. The Clark Fork Coalition and the Flathead Lake Protection
Association (FLPA) recommended that land treatment should be
preceded by a full-scale demonstration or experiment
designed to determine whether the system is capable of
meeting required criteria within a specified period of time.
The FLPA commented that completion of only an "equivalency
demonstration" whereby Somers soils are shown to be the same
as those at Paradise would be inadequate and that the
demonstration must show that contaminants will not migrate
out of the unit. The FLPA further commented that the
contaminants of interest should include nitrogen and
petroleum compounds as well as secondary metabolic products.
EPA Response: The construction and operation of a land •
treatment unit at the Somers Site must be conducted in
accordance with the requirements of the Resource
• Conservation and Recovery Act (RCRA). These requirements
include a demonstration that a proposed land treatment
operation be capable of completely degrading, transforming
or immobilizing hazardous constituents in the treatment
zone. For a new unit, such as that at Somers, the
demonstration may consist of field tests, laboratory
analyses or available data. Any laboratory analysis or
field test must a) accurately simulate the characteristics
and operating conditions for the proposed treatment unit, b)
be likely to show that hazardous constituents in the waste
will be completely degraded, transformed or immobilized in
the treatment zone, and c) be conducted in a manner that
protects human health and the environment, including the
potential for the migration of hazardous constituents to
ground water or surface water.
It is EPA's intention to use a combination of available data
from the Paradise land treatment demonstration and
laboratory analysis to determine the operating conditions
necessary at Somers. Most of the nitrogen and petroleum
compounds and secondary metabolic products mentioned by
commentors are not listed hazardous constituents under RCRA
(in many cases the breakdown products are unknown) and there
is little or no information about the toxicity or
carcinogenicity of these compounds. Rather than attempt to
identify such compounds, the land treatment demonstration
and the operation of the land treatment unit will include
tests to determine whether the constituents present at
completion of treatment are toxic or mutagenic.
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14. The Clark Fork Coalition and the Flathead Lake Protection
Association recommended that the land treatment cells should
be double-lined and equipped with a leachate collection and
leak detection system, that any leachate collected should be
handled as a hazardous waste, and if a leak is detected
corrective action should begin immediately.
. EPA Response: Although not required under the applicable
RCRA regulations, the Somers land treatment unit will be
underlain by a liner with a leachate collection system in
order to assist in a demonstration of no-migration. Any
leachate collected will be recycled as irrigation water for
the land treatment unit or treated in the ground water
treatment system, if necessary. The specific type of liner
system for the land treatment unit will be determined during
remedial design. Depending on the nature of the liner
system which is finally chosen, a leak detection system may
or may not be possible. For example, a liner system
consisting of a synthetic liner underlain by a clay liner
would not allow the effective use of a leak detection
system. Typically, land treatment units are not underlain
by any kind of liner. The Paradise land treatment
demonstration, which was conducted without a liner, showed
that hazardous constituents remained in the treatment zone.
The use of a liner at Somers would provide a further '
guarantee that no constituents can escape below the unit.
If monitoring were to indicate that hazardous constituents
have escaped the treatment unit, corrective action would
immediately be required.
15. One commentor asked whether there was any evidence that land
treatment was effective. Another commentor asked whether
land farming methods had ever been tried using a liner
system.
EPA Response: Land treatment has been used for over 25
years to treat oily sludges in the petroleum industry. Land
treatment of creosote waste is being done at the BN facility
in Brainerd, Minnesota, at the Brown Wood Preserving Site in
Live Oak, Florida and the Scott Lumber site in Alton,
Missouri and has been selected as the treatment method for
the BN facility in Paradise and the Champion Mill in Libby,
Montana. Except for the Paradise facility, all of these
treatment units are underlain by a liner system.
16. A commentor asked whether creosote would get into the food
chain if crops were planted on the closed unit.
EPA Response: Pursuant to applicable RCRA requirements,
after a land treatment unit is closed, food crops can only
be grown if a demonstration is made that hazardous
constituents will not be transferred to food or feed
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portions, of the crop or be ingested by grazing food chain
animals and that soil contaminant concentrations are not
greater than those in untreated soils from the same region
under similar conditions.
17. A Somers resident asked about the visual appearance of a
land treatment unit and whether this would affect property
values in Somers.
EPA Response: A typical land treatment unit resembles an
unvegetated plowed field. The soils to be treated are
applied in a flat layer and periodically irrigated and
tilled. Because the Somers unit will be lined, the liner
will be visible at the boundaries of the unit. The unit
will be bermed to prevent any runoff of rain water. The tie
plant buildings will probably be demolished and removed
prior to construction of the unit. The drip track, and
possibly the spur line at the Site will also be removed.
Because of the removal of these structures, many of which
are not in good condition, the appearance of the plant •
property may be improved. Although there may be no short-
term improvement in property values during the treatment
period, it is not expected that property values will
decline. At the completion of cleanup the property values
in the town may increase due to improved environmental
conditions.
18. A commentor asked whether there is a technology available to
degrade the contaminated soils without tilling them and
which would allow the soils to be covered with vegetation
during the degradation period.
EPA Response: The land treatment process involves the
breakdown of contaminants by soil bacteria. The bacteria
require oxygen to live and grow. Biweekly tilling is
necessary to ensure that all the soils receive enough oxygen
to support the bacteria necessary for contaminant breakdown.
It is therefore not possible for vegetation to be grown on
the unit.
19. A commentor asked whether the treatment unit size would be
enlarged or the thickness of soils applied to the unit
increased if additional soils are found which need to be
treated.
EPA Response: It is not expected that soil volumes will be
significantly greater than anticipated, since a safety
factor was provided in calculating the expected volume.
However, if additional soils are found which require
treatment, the period of treatment will be extended to allow
. for additional applications of soil. Each application of
soil is limited by the depth to which tilling can
15
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0100715
effectively occur (approximately 10 inches); however,
subsequent applications can be made after each previous
application is treated to acceptable levels. The treatment
unit size will not be enlarged, in order to keep the unit as
far as possible from local houses.
20. A commentor asked what the source of the irrigation water
would be.
EPA Response: Ground water collected as part of the aquifer
cleanup will be treated and some of the water will be used
for irrigating the land treatment unit. Any leachate
collected from the treatment unit would also be used as
irrigation water.
21 . A commentor asked whether the land treatment unit could be
constructed so that windy conditions would not cause a
release of dust into the air. Another commentor asked who
would regulate such emissions.
EPA Response: The land treatment demonstration must include
the development of appropriate management and operating
methods to control dust emissions from the unit. Soil
moisture in the unit will be carefully controlled to ensure
that the bacteria receive adequate moisture to survive and
break down the contaminants. Additional moisture will be
added as necessary to ensure that the soils do not generate
dust during dry windy days. Because the land treatment
activities will be conducted on a Superfund Site, the lead
regulatory agency, in this case EPA, will be responsible for
ensuring that these practices are followed.
22. A commentor asked whether the soils which have been treated
will be removed before a subsequent layer is applied or
whether the additional soils will be placed on top of
treated soils.
EPA Response: The additional soils will be placed in a
layer on top of the previously treated soils. It is
expected that a maximum thickness of about 20 inches will
accumulate in the unit before closure.
23. The FLPA recommended that at closure, the land treatment
unit be covered with a vegetative, rather than an
impermeable cap. The Association suggested providing
drainage through the liner after a demonstration that water
infiltrating the closed treatment unit would present no
health risk.
EPA Response: If the cleanup of soils proceeds to the
that any water passing through the soils meets health-basec
concentrations and would not exceed any other applicable or
16
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0100716
relevant and appropriate requirements, then the liner system
may be perforated and the unit covered with a vegetative
cap. If the soil cleanup proceeds to the point where the
soils have met health-based concentrations, but water
passing through the soils contains contaminant
concentrations above levels acceptable for drinking water,
then an impermeable cap will be necessary to prevent
rainwater from entering the unit. This determination will
be made by collecting and analyzing any leachate produced in
the unit.
24. A number of commentors asked what future use could be made
of the area used for land treatment.
EPA Response: The EPA Record of Decision requires that land
treatment continue until contaminant concentrations are
reduced to levels acceptable for direct contact. Once these
levels have been achieved the soils may no longer be
considered a hazardous waste, if the requirements of 40 CFR
Part 260.22 are met. However, if treatment does not result
in contaminant concentrations at or below background, use of
the property would be restricted and long term monitoring of
the unit would be required.
25. BN commented that incineration is not as permanent or
environmentally sound as land treatment and should therefore
not be considered as a contingency alternative for soil
remediation. In support of this argument, BN referenced
CERCLA requirements that remedies be permanent solutions,
take into account the long-term uncertainties associated
with land disposal, and the short- and long-term potential
for adverse health effects from human exposure. BN argued
that incineration could produce air emissions and would
produce an ash which must be landfilled, thereby failing to
meet the requirements of CERCLA, while land treatment
produces emissions of less concern and a residue which does
not require landfilling.
EPA Response: For the following reasons, EPA argues that
incineration meets the statutory requirements of CERCLA: a)
Incineration is a method of treatment which permanently and
effectively reduces the toxicity of soils. For creosote
constituents, incineration has been determined by EPA to be
the best demonstrated available technology (e.g., able to
reduce the concentration of contaminants to the lowest
levels possible), b) The ash which remains after
incineration typically contains residual levels of creosote
constituents which are so low, if present, that the material
may no longer be considered a hazardous waste. The ash may
then be handled as a solid waste. Even if the waste is
still considered hazardous, the residuals are typically
lower than with any other available method. c) Although
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0100717
incinerators do produce air emissions, these can be very
effectively removed to render the air stream safe for
release to the atmosphere.
Although incineration is the best demonstrated available
technology for creosote, biological treatment methods such
as land treatment provide comparable levels of cleanup for
soil and debris contaminated by creosote. Land treatment
can also produce some air emissions, although for creosote
wastes these can relatively easily be controlled within
health-based levels. Although land treatment residuals do
not require landfilling, EPA considers the land treatment
unit itself to be a land disposal unit subject to the land
disposal restrictions. EPA has selected land treatment as
the first method of choice for treating the Somers soils.
However, if the additional areas outlined in the contingency
remedy are excavated, incineration will be used to treat the
soils.
26. Because the same cleanup concentrations would apply to both
land treatment and incineration, BN argued that incineration
would significantly increase the cost of the contingency
remedy without improving its effectiveness. BN commented
that incineration is therefore not a cost-effective
alternative, contrary to the mandate of CERCLA.
EPA Response: CERCLA does require that the selected remedy
be cost effective, however cost effectiveness is determined
by evaluating a number of effectiveness criteria (long- and
short-term effectiveness and reduction of toxicity, mobility
and volume through treatment) against the corresponding cost
of an alternative. Both land treatment and incineration
provide good long-term effectiveness and reduction of
toxicity, mobility and volume; however, incineration can be
completed in a much shorter time than land treatment when
considering a very large volume of soil. The contingency
remedy involving excavation of approximately 98,300 cubic
yards of soil would take approximately 50 years to land
treat versus two years to incinerate. The contingency
remedy involving excavation of 53,500 cubic yards of soil
would take approximately 30 years to complete, versus two
years to incinerate. In addition to achieving treatment
concentrations in a much shorter time, incineration does not
require the long-term management of hazardous waste storage
and treatment facilities. In EPA's judgement, the preceding
reasons are sufficient to make incineration more cost
effective than land treatment.
27. BN proposed that if, based on pilot testing, ground water
remediation is found not to be practicable at the Site, the*
contingency remedy for treating the large volume of soils
which would be excavated should be land treatment at both
18
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0100713
Paradise and on-site at Somers. BN argued that short-term
effectiveness concarns relating to the long-term operation
of a treatment unit and a waste pile are not significant
reasons to abandon land treatment in favor of incineration.
EPA Response: Based on significant public comment in
opposition to land treatment of Somers soils at Paradise and
a request by the MDHES that EPA reconsider its preference
for this option, EPA has decided not to send soils to
Paradise for treatment. All of the soils which would be
excavated under the contingency alternatives would therefore
have to be treated entirely on-site. Land treatment under
Contingency A would require approximately 50 years to
complete while Contingency B would take approximately 30
years. Incineration under either contingency would take
approximately 2 years. Based on a consideration of the time
involved to treat and manage the soils versus the cost of
treatment, and the other reasons discussed under comment 126
above, EPA selected incineration under both contingency
options. '
28. The FLPA commented that incineration would pose potentially
unacceptable air emission risks, particularly in light of
the inversions common to the upper Flathead Valley.
EPA Response: EPA does not agree that the risks of
incineration would be unacceptable. Gaseous emissions can
be controlled by secondary burning or paralysis and air
scrubbing, resulting in a stream safe for release to the
atmosphere.
Ground Water Alternatives
1. BN commented that EPA's proposed plan did not define under
what circumstances ground water remedies will be considered
effective, a determination which will be important in
deciding under what circumstances EPA will abandon ground
water remediation in favor of deep excavation of soils. BN
recommended that both technical and economic considerations
be included in making this decision.
EPA Response: In deciding under what circumstances ground
water remedies would be abandoned in favor of source removal
and treatment, EPA would use the same technical evaluation
criteria used in the initial selection of a remedy. These
criteria include: overall protection of human health and the
environment, compliance with other environmental laws,
reduction in toxicity, mobility or volume, long-term
effectiveness, short-term effectiveness, implementability
and cost.
2. The FLPA recommended that modeling efforts be used to design
19
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0100719
remediation and evaluate alternatives, but cautioned
available data from aquifer slug tests are uninterpretable
(specific concerns are outlined below under Comment 3.).
The Association recommended that additional aquifer tests be
conducted and the modeling conducted during the RI/FS be
repeated taking into account the inhomogeneity and
anisotropy of the affected aquifer and the lack of
unidirectional steady state flow.
EPA Response: EPA does not agree that a repetition of the
modeling exercise conducted during the RI/FS would be
worthwhile, even after collection of additional field data.
The RI/FS modeling effort examined the sensitivity of
predicted contaminant transport to various input parameters.
The model exhibited sensitivity to a number of parameters in
addition to hydraulic conductivity, notably retardation
coefficient, initial source concentration and solute decay
rate. The results were relatively insensitive to the
dispersivity of the aquifer. Even if some improved
parameter estimates could be obtained with additional field
studies, the sensitivity of the model to source
concentrations and solute degradation rates would result in
a model with uncertainties comparable to the current
results. It is unlikely that additional data or modeling
will affect the choice of a preferred remedial alterna
or the requirements for additional aquifer testing and
testing of the ground water cleanup alternative.
It will be necessary to refine the current estimates of
hydraulic conductivity and other parameters that will affect
the behavior of the hot water flushing and in-situ
bioremediation well fields. This information can be
efficiently performed as part of the pilot test of the
remedy. Additional modeling efforts will be useful in the
planning and analysis of the pilot test. This modeling will
take into consideration the heterogeneity and anisotropy of
the aquifer, seasonal variation in Flathead Lake stage, and
thermal effects. The pilot study will incorporate all
aspects of the planned operation, including thermal effects,
effects of oxygen injection and effects of nutrient
addition. It will also incorporate adequate monitoring of
ground water conditions, particularly near Flathead Lake and
will address local geochemical factors such as high iron and
calcium concentrations, and well as biochemical effects.
During drilling of additional wells necessary for pilot
testing, additional stratigraphic information will be
obtained and parameters such as grain size distribution,
thermal coefficients, organic carbon content and microbial
populations will be measured. Additional aquifer testing
will also be used to confirm site-specific aquifer i
properties such as hydraulic conductivity, specific yield,
and possible leaky effects, constant-head boundary effects
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0100720
and anisotropy of individual strata.
3. The Flathead Lake Protection Association commented that the
slug test results in the Somers FS vere uninterpretable.
Specific comments and responses are provided below:
a. Background water level fluctuations should be measured
for an extended period of time prior to the test.
EPA Response: The water table fluctuations at the Site were
monitored with continuous recorders on several wells and the
fluctuations in water table elevations were generally not
discernible from day to day. Therefore, it was not expected
that fluctuations would occur during the 20-minute period
used to conduct each slug test.
b. The slug should have a known volume.
EPA Response: The slug used by Remediation Technologies was
10 feet long with a radius of 0.07 foot and thus a volume of
0.14 cubic foot.
c. No statement was made regarding whether or not the
initial displacement was calculated or measured.
EPA Response: The initial displacement, Ho/ was measured
rather than calculated. Ho was determined using the depth
to water measured at the instant after slug removal, based
on the transducer reading. The amount of time that elapsed
between slug removal and transducer introduction averaged
about ten or twenty seconds. Since there was not a large
aquifer response early in the test after the transducer was
placed, the lag time in slug removal and water level
measurement was not considered significant.
d. Since the transducer was lowered after the slug was
removed, initial displacement could not be measured,
therefore the displaced volume which must be known is
not reported.
EPA Response: As noted above, the slug volume was 0.14
cubic foot. The transducer was lowered immediately after
slug removal in order to obtain, as nearly as possible, a
measurement of the initial water level displacement.
e. No mention was made whether or not the transducer was
set at some measured depth.
EPA Response: The transducer was lowered in the well until
the water table was encountered. The depth at which the
transducer was placed was then measured and noted. The
transducer readings, which measure height of water above the
21
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U l U U ( i
transducer, were then converted to depth below the surveyec^
measuring point using the measured depth of the transducer.
this depth to water, in feet, is reported on the data tables
as the "water level" measurement.
4. The FLPA and other commentors requested that, prior to EPA
acceptance of bioremediation of ground water for the Site,
potential impacts of the treatment process on Flathead Lake
(such as nitrate addition) and ground water management
techniques be evaluated.
EPA Response: EPA agrees. As outlined in this Record of
Decision, pilot testing of the ground water alternative will
be conducted. This testing will include an evaluation of
the effectiveness of the system to contain nutrients used
for in-situ biological treatment.
5. A commentor asked what nutrients would be used in ground
water treatment, in what concentrations and how they would
be injected.
EPA Response: The nutrients typically used in biological
ground water treatment include nitrogen and phosphorus.
The nutrients will be stored in solid form, then liquified,
diluted, and injected into the aquifer through wells.
Hydrogen peroxide will be used to provide an oxygen source I
The peroxide will be stored in a 35% strength and diluted to
a 0.03 to 0.05% solution for injection.
6. A commentor asked whether EPA would test the hot water
flushing methodology. Another commentor asked how long
ground water treatment would take.
EPA Response: Both the hot water flushing and in-situ
biological treatment systems will be pilot tested to
determine their practicability in both the swamp and CERCLA
lagoon areas and to develop operating parameters for the
systems. The anticipated time -necessary to complete actual
treatment using these methods is approximately 10 years.
7. A commentor asked why EPA is making a recommendation for
ground water cleanup without knowing whether the alternative
will work or not.
EPA Response: Based on the hydrogeological information
available for the Site, EPA believes that ground water
remediation will be effective. However, pilot testing will
be required to refine the available understanding of Site
conditions and to determine whether such treatment will be
practicable (i.e., effective in a reasonable period of
time). In case ground water treatment proves to be
impracticable, EPA has also selected contingency
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0100722
alternatives which involve excavation and treatment of
source area soils.
8. A commentor asked whether the injection wells would last for
the 10 years expected for treatment or whether they would
tend to plug up.
EPA Response: Plugging of injection wells is a potential
problem due to the formation of iron precipitates or the
buildup of excessive amounts of bacteria. This effect can
be minimized by carefully regulating the amounts of injected
oxygen and nutrients. Pilot testing will be used to
determine operating parameters necessary to control
plugging.
9. A commentor expressed concerns that pumping ground water
would decrease ground water discharge to the slough which
would then be unavailable for irrigation.
EPA Response: Pumping of ground water will occur in the
area in and downgradient from the CERCLA lagoon (south af
Somers Road) and in the swamp area along Flathead Lake.
• Pumping of ground water will not occur in or upgradient from
the slough; therefore ground water discharge to the slough
should be unaffected by the ground water remediation
project.
10. A commentor asked whether there would be a guard or posted
"keep out" signs around any hazardous materials which would
be stored on site such as fertilizer or hydrogen -peroxide
and whether security would be improved at the site to
prevent access to the treatment unit or the buildings on the
site.
EPA Response: Any materials which could be hazardous to
human health or the environment will be appropriately
managed. This may involve locking the material in a secure
storage area or posting warning signs. The materials used
in land treatment of soils and treatment of ground water
consist mainly of fertilizer and hydrogen peroxide.
11. A commentor asked where the ground water treatment unit
would be located and whether it would be secured.
EPA Response: The location of the ground water treatment
system will be determined during remedial design; however,
the system will be located on BN property. The treatment
unit will be secured to prevent any risk to the public and
to prevent vandalism of the unit.
23
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0100723
Cleanup Concentrations
1. The Clark Fork Coalition and the Flathead Lake Protection
Association recommended that the end result of land
treatment should be contaminant concentrations achievable
using the RCRA Best Demonstrated Available Technology for
.creosote contaminated soils and a one in one hundred
thousand (1 x 10~5) to one in one million (1 x 10~6)
carcinogenic risk level for any other listed hazardous
constituent and for any secondary metabolic or physico-
chemical degradation intermediates or products which will
result from the transformation of primary constituents. The
use of a Microtox assay was suggested prior to closure. In
addition, the Coalition recommended that prior to final
closure of the land treatment unit, the soils should be
treated so that they are no longer considered hazardous
under RCRA and the delisted waste should be disposed of in
an off-site landfill.
EPA Response: The EPA proposed plan recommended that land
treatment continue until RCRA Best Demonstrated Available
Technology concentrations were achieved and the total
concentration of carcinogenic polynuclear aromatic
hydrocarbons was less than 36 mg/kg (1 x 10"^ risk level).
After consideration of public comment, EPA is further
requiring that once these initial levels are achieved,
treatment will continue until the net change in total PAH
concentration from the preceding year is less than 20%.
EPA shares the concerns of commentors that secondary
products of biological degradation may also be harmful to
human health and the environment; however, there is
insufficient information both on the nature of these
secondary products and their toxicity to develop a risk
level for cleanup. Microtox or Ames assays can be used to
evaluate toxicity and mutagenicity, but results do not
directly correlate to human or animal health effects. The
use of such assays will be required during land treatment,
however, in order to ensure that the toxicity and
mutagenicity of the residual soils has decreased with
treatment.
The RCRA standard for delisting material (a finding that the
material is no longer hazardous) is based on the material
meeting health-based levels. Since this Record of Decision
requires a reduction in concentrations to health-based
levels, the treated soils may be "delistable", if the
requirements of 40 CFR Part 260.22 are met.
EPA will not require that the treated soils be removed from|
the land treatment unit and moved to another disposal
location. A land treatment unit is considered to be both a
24
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0100724
treatment, and a disposal facility under RCRA. Because soils
will be applied to the land treatment unit after the
effective date of the RCRA land disposal restrictions, a
demonstration that the waste will not migrate out of the
unit will be made. Furthermore, the soils must be treated
to health-based levels prior to closure. EPA therefore
finds no reason to remove the soils from the unit once
treatment is completed.
2. The Clark Fork Coalition suggested that the determination of
a risk level for secondary products of degradation might be
accomplished used a linear extrapolation from the primary
contaminant risk levels or might be based on mutagenic
potency.
EPA Response: As discussed above, there is inadequate
information on both the intermediate breakdown products of
land treatment of creosote-contaminated soils and the health
effects of these products to determine risk levels
associated with various concentrations. Since there are,a
large number of polynuclear aromatic hydrocarbons (PAHs) and
since each may form a large number of degradation products,
there are hundreds or thousands of possible compounds to
consider. There is no scientifically valid way to estimate
the carcinogenic risk of a chemical mixture without knowing
a) the chemical identity of all chemicals present, b) the
concentration of each, and c) the cancer potency factor for
each. This is presently impossible for the breakdown
products of the PAHs.
Although an Ames test can be used to measure mutagenicity,
mutagenic potential does not necessarily correlate with
carcinogenic potential. Moreover, it would not be possible
to distinguish PAH-related mutagenicity from that due to
natural compounds or other contaminants in the soil.
Although the Ames test may be useful in confirming or
refuting the assumption that residual PAHs (and/or other
contaminants) are undergoing degradation to less
biologically active molecules, it is not possible to
identify a specific level of mutagenic activity that is
acceptable.
It is important to note that, while the potential cancer
risk from PAH degradation products is not trivial, both the
exposure assessment and risk assessment use accepted EPA
standards and assumptions which are conservative. For
example, in the Somers risk assessment, the assumption that
all PAHs are as carcinogenic as benzo(a)pyrene is believed
to be very conservative; the margin of safety generated by
this and other assumptions should compensate for any
. carcinogenic activity contributed by PAH intermediate
degradation products.
25
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0100725
3. BN commented that EPA's cleanup goals ignore the most
current scientific information. BN recommended using a
relative potency approach to developing cleanup goals based
on the following arguments:
a) In developing cleanup concentrations for Somers, EPA
used a Cancer Potency Factor for polynuclear aromatic
hydrocarbons (PAHs) which was based on the assumption that
the carcinogenic potency of all carcinogenic PAH compounds
were equal to that of Benzo(a)pyrene, the most carcinogenic
of the PAHs (the "traditional potency approach"). According
to BN, this Cancer Potency Factor has been withdrawn by EPA
and calculations using this number are unnecessarily
conservative.
EPA Response: EPA has not withdrawn the original cancer
potency factor for benzo(a)pyrene, although revisions to
this factor are under consideration. It is generally
understood that :most carcinogenic PAH compounds are less
potent than benzo(a)pyrene and EPA is in the process of
developing relative potency factors for a number of these
compounds. However, the new potency factor for
benzo(a)pyrene and relative potency factors for other PAHs
have not yet been finalized. For this reason, and also to
account for the presence of other carcinogenic compounds
which are not typically analyzed for (see comment number
two), EPA continues to base its cleanup levels on the
original, more conservative numbers.
b) Various authors have analyzed the individual potencies
of the various PAH compounds and note a variation relative
to Benzo(a)pyrene (the "relative potency approach").
EPA Response: See response to a), above.
c) An EPA decision at the Brown Wood Preserving Site
utilized the relative potencies of the PAHs in developing
cleanup goals.
EPA Response; EPA continues to base its Somers cleanup
concentrations on the traditional approach. This approach,
equating the potency of all carcinogenic PAH compounds to
that of benzo(a)pyrene has also been followed at a number of
other Superfund sites (Libby Ground Water Site, Libby,
Montana; BN Brainerd Site, Brainerd, Minnesota; Reilly Tar
and Chemical Company Site, St. Louis Par, Minnesota).
d) The EPA RCRA Facility Investigation Guidance and EPA's
proposed listing of certain wood treating wastes as
hazardous both use the relative potency concept.
26
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0100726
EPA Response: The RCRA Facility Investigation Guidance
clearly specifies that the health based concentrations
provided were developed-using relative potency values which
are still under EPA review.
e) The relative potency approach is more scientifically
sound than the traditional potency approach and is therefore
more consistent with the EPA "Superfund Public Health
Evaluation Manual" (Exec. Summ. pg. 3) and "EPA's ."CERCLA
Compliance with Other Laws" guidance (pp. 1-76 and 1-85).
EPA Response: The referenced section of the Superfund
Public Health Evaluation Manual discusses the process of
changing toxicity data in EPA's databases as new information
becomes available. However, the revised potency factors for
the PAH compounds have not yet been finalized or been
approved by EPA or added to its databases. The referenced
sections of the CERCLA Compliance with Other Laws manual
discuss the use of criteria, advisories and guidance as "To
Be Considered" in developing cleanup criteria. However,. EPA
has not published the PAH relative potency factors as
criteria, advisories or guidance in final form.
f) BN urged EPA to consider the effect the Relative Potency
Approach would have on the amount of soil which would be
excavated and treated and on ground water remediation
timeframes and the cost of remediation. BN also asked EPA
to consider the conservative assumptions which are already
built into the risk assessment process.
EPA Response: The effect of the volumes of soil and cleanup
timeframes is irrelevant to the development of cleanup
concentrations which are based on risk assessment. EPA
agrees that conservative assumptions, in addition to the
cancer potency factors, are already built into the risk
assessment process. However, because of the number of
potentially carcinogenic compounds associated with creosote
which are not routinely analyzed for at the Site and because
of the lack of available information on these compounds, EPA
feels that a conservative approach is warranted. In
summary, EPA is retaining the cleanup levels presented in
the proposed plan.
BN argued that EPA's ground water cleanup goal of 0.3 ppb
for total PAH ignores EPA's own published risk-based PAH
standards for individual PAH compounds because the EPA goal
is so much lower than these standards. The standards
referenced by BN include various ambient water quality
criteria as well as health-based water concentrations for
two carcinogenic PAH compounds.
EPA Response: The cleanup concentration for total PAH in
27
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0100727
ground water was set below levels published for individual
PAH compounds because of the possible presence of other
suspected or known carcinogens, such as the nitrogen-bearing
heterocyclic compounds and aromatic amines, which are not
routinely analyzed for and for which little toxicity
information exists. Also, a number of PAH compounds,
although not in themselves cancer-causing, may promote the
cancer activity of other carcinogens. Since the cleanup
concentration for the total of the carcinogenic PAHs, which
are typically the most difficult to degrade, is 0.03 ppb or
an order of magnitude less than that for total PAH, the
cleanup concentration for total PAH should also be
achieved by treatment. A total PAH concentration of 0.3 ppb
will assure that all creosote compounds are being reduced to
acceptable levels. This approach has also been taken at the
BN site in Brainerd, Minnesota, the Reilly Tar and Chemical
site in St. Louis Park, Minnesota, and the Libby Ground
Water Site, in Libby, Montana. Furthermore, considering
that the cleanup level for carcinogenic compounds would
result in a 10~5 rather than EPA's goal of a 10~6 health
risk, it is appropriate to take a more conservative approach
to cleanup of total PAH compounds.
5. BN commented that EPA's proposed PAH ground water cleanup
goals are so low as to be unverifiable using reliable,
accepted, and practical analytical methods. BN proposed to'
set ground water cleanup goals at the practical quantitation
limits using EPA's "Test Methods for Evaluating Solid
Waste," Method 8310 (SW-846) consistent with the approach
proposed by BN in their RCRA ground water correction plans
for the Somers and Paradise plants.
EPA Response: Methods presented in SW-846 will not achieve
detection at the concentrations required for the cleanup
concentrations at the Site. EPA does not argue that the use
of standard analytical methods would allow verification of
the established ground water cleanup concentrations.
However, these concentrations can be verified using special
sampling and analysis techniques such as those used by both
EPA and BN during the RI/FS. Furthermore, the need for low
(part per trillion) detection limits will not occur for some
years until concentrations have been considerably reduced by
treatment.
6. The Flathead Lake Protection Association (FLPA) commented
that, while EPA's cleanup goals for PAH contaminants in soil
and ground water were acceptable, standards for volatile
compounds, such as benzene, and standards for heterocyclic
nitrogen compounds (.which may be more serious carcinogens
than PAHs) should also be provided.
EPA Response: EPA has established a Safe Drinking Water Act
28
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0100728
Maximum Contaminant Level for benzene of 5 ug/1. This
concentration will be a cleanup standard for the Somers Site
if benzene is detected in ground water. EPA has not set
standards for the heterocyclic nitrogen compounds, some of
which are carcinogenic. Since no cancer potency factors are
available for those compounds, no risk-based cleanup
standards can be derived. Instead, EPA has set the total
.PAH cleanup concentration at a level intended to account for
the presence of compounds which may be of concern but about
which little toxicity or carcinogenicity information exists.
7. The Montana Department of Health and Environmental Sciences
(MDHES) commented that EPA's treatment goals for soils were
not sufficiently stringent. The State recommended
continuation of land treatment to background concentrations
in order to ensure that the land treatment unit could
undergo clean closure without restrictions on the future use
of the property.
EPA's Response: In order to accommodate the State's
concerns, and as noted above under comment number 1 above,
this Record of Decision specifies, that once the initial land
treatment concentrations specified in EPA's proposed plan
are achieved, land treatment will continue for at least
another year. If a 20% or greater total PAH reduction is
achieved during this year, then treatment must continue
until the decrease in total PAH has been less than 20% from
the previous year. At this point another application of
soil may be made or the facility may be closed. If the
final contaminant concentration is at background, no post-
closure care will be required. If the leachate produced
from the unit is within EPA's cleanup concentrations for
groundwater, the liner may be perforated and the unit
covered with a vegetative cap. If the leachate is at
concentrations greater than EPA's cleanup concentrations for
ground water, the intact unit must be covered with an
impermeable cap. In either case, if soils are contaminated
above background concentrations, RCRA post-closure care
requirements will be imposed.
General Technical Comments on Remedial Alternatives
1. A commentor asked what criteria would be used to determine
how long a time is too long to conduct a treatment operation
such that another alternative would be selected.
EPA Response: In deciding under what circumstances one
treatment method would be abandoned in favor of another, EPA
would use the same technical evaluation criteria used in the
initial selection of a remedy. These criteria include:
overall protection of human health and the environment,
compliance with other environmental laws, reduction in
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toxicity, mobility or volume, long-term effectiveness,
short-term effectiveness, implementability and cost. If it
were determined that an alternative other than those
contained in the selected and contingency alternatives were
necessary, EPA would request public comment on its proposal
to implement such an alternative.
2. The FLPA expressed concerns regarding possible impacts from
the Site on the proposed Somers bedrock water supply.
Because the bedrock aquifer appears to be unconfined, the
nature and degree of contact between the bedrock and the
contaminated aquifer must be defined. Prior to any
acceptance of a remedial action, the FLPA recommended that
EPA evaluate the degree of connection and potential impacts
of increased local ground water utilization.
EPA Response: As outlined in the Feasibility Study, an
extended pump test of one of"the new municipal supply wells
will be undertaken to ensure that aquifer parameters of ,
interest are obtained. Pump test results will be analyzed
to ensure that drawdown will not ultimately result in
additional spreading^ of ground water contamination at the
Site or contamination of the municipal supply.
Use of the Paradise Land Treatment Facility
1. Paradise residents expressed concerns that contaminants
might escape the land treatment unit and contaminate the
local aquifer.
EPA Response: Burlington Northern conducted a land
treatment demonstration at Paradise which showed that
contaminants were retained within the upper few feet of the
soil profile (the treatment zone) and were not released into
the aquifer. Based on a review of this demonstration, as
well as other permit application material, the Montana
Department of Health and Environmental Sciences found that
the proposed operation was environmentally sound and granted
BN a permit for land treatment of contaminated soils
currently at the Paradise sa,te.
2. Paradise residents expressed concerns that the Somers soils
would be placed in piles at ;the Paradise site and that local
drainage could be affected.
EPA Response: Although the,final EPA decision will not
involve transportation of Somers soils to Paradise, the
original proposal would have involved transporting the soill
to Paradise and immediately applying the soils in a smooth
layer onto the land treatment plot. The soils would not
have been placed into piles, therefore local.drainage would
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not have been affected.
3. A Paradise resident expressed concerns that BN may use so
much water during land treatment that it could affect other
water users.
EPA Response: BN applied for a license from the local
Paradise water board for a well to withdraw water for
irrigating the land treatment unit. However, the location
of this well would be downgradient from other nearby users
(such as the town of Paradise), therefore local users should
not be affected.
4. Paradise residents asked MDHES about dump trucks and tank
trucks seen entering and leaving the Paradise facility. The
public was concerned that BN was illegally dumping material
at the site.
EPA Response: The dump trucks seen entering the facility
were carrying rip rap to be used in armoring the existing
waste pile which sits partially in the floodplain of the
Clark Fork River. Tank trucks were used to empty two tanks
at the site and to periodically remove water which
accumulates in the waste pile.
5. A Paradise resident asked how much of the soil now at
Paradise was taken from Somers during the 1985 removal
action.
EPA Response: 3,000 cubic yards, or about 15% of what is
currently in the Paradise waste pile, is soil which was
removed from Somers in the 1985 Emergency Removal from the
swamp pond area. The remaining soils in the waste pile are
from the Paradise facility.
6. Paradise residents expressed concerns about the recent
burning of buildings at the Paradise facility. An insulated
storage tank caught fire and residents were concerned that
fumes from the fire might be toxic. Residents were also
concerned that BN was operating without good oversight from
the State or EPA.
EPA Response: BN contractors hired to demolish the
buildings at the Paradise plant chose to burn some of the
buildings without obtaining a necessary permit from the
State Air Quality Bureau or notifying State or Federal
authorities, although a local permit was obtained. The Air
Quality Bureau has issued BN a citation for violation of
State Air Quality rules.
7. Paradise residents asked for a guarantee that wheat could be
grown in five years on the land treatment unit.
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EPA Response: No guarantees can be made, however the land
treatment demonstration at Paradise indicates that treatment
to very low residual contaminant levels is possible. In
order to grow food chain crops on the treatment plot, BN
must demonstrate that no substantial risk to human health
and the environment would result. This demonstration must
show that hazardous constituents will not be transferred to
food or feed portions of the crop or be ingested by grazing
food chain animals and that soil contaminant concentrations
are not greater than those in untreated soils from the same
region under similar conditions.
8. A number of Paradise residents expressed concerns that the
2-year land treatment demonstration conducted at the BN
Paradise facility was not long enough and that common sense
indicated that creosote contaminants could not be broken
down by biological activity.-:
»
EPA Response: The land treatment demonstration, which •
operated for a period of 1/2 years, indicated that creosote
contaminants could be effectively broken down within an
anticipated 4 to 5 year period. Although in high
concentrations creosote is used to prevent the biological
breakdown of wood products, in low concentrations, such as i
those in soil, bacteria are able to metabolize creosote and
break it down into nonhazardous constituents.
9. The Eastern Sanders Conservation District and others
commented that the Paradise site is on the flood plain of
the Clark Fork River, is very close to the river banks, and
in the event of a flood, the;creosote contaminated soils
might be dumped directly into the river. The District
requested that BN locate a suitable site outside of the
flood plain. I
EPA Response: The land treatment unit at Paradise is
already located completely outside of the floodplain.
t
10. A Paradise resident asked whether the BN Paradise Site could
be added to the National Priorities List (NPL) of Superfund
sites.
i
EPA Response: In 1980, EPA conducted a Preliminary
Assessment and a Site Inspection to evaluate whether the
Paradise facility should be Included on the Superfund NPL.
Based on this evaluation, it was determined that Resource
Conservation and Recovery Act (RCRA) authorities were
sufficient to bring about corrective action of all
environmental problems at the plant. EPA's policy is to
defer to RCRA authority wher.e such authority is sufficient
to assure cleanup; therefore, the Paradise Site is not
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eligible for the NPL.
11. Paradise residents inquired whether the community would be
eligible for an EPA Technical Assistance Grant.
EPA Response: EPA Technical Assistance Grants are only
available to communities affected by a Superfund site. A
maximum of one grant is available per site. In 1988, the
Flathead Lake Protection Association received a Technical
Assistance Grant for activities related to the Somers Site.
The FLPA will work with other interested groups to provide
information or interpretation of data related to the Site.
12. Paradise residents asked how the public was notified of the
Paradise RCRA permit action and recommended that articles in
the newspaper be used rather than legal notices.
EPA Response: MDHES initially informed the public of the
RCRA permit action by legal notice in the following
newspapers: the Missoulian, the Plainsman, the Sanders
County Ledger and the Kalispell Daily Interlake. A mailing
. was also sent to all individuals on the mailing list for the
site and notices were sent to radio stations KUFM and KDXT
in Missoula. When it became apparent that this approach was
not reaching all interested parties, MDHES undertook a mass
mailing to all Paradise box holders. A public meeting was
held in the nearby town of Plains, Montana.
Health and Environmental Effects
1. One commentor asked about the effect of zinc on
environmental populations.
EPA Response: Zinc is an essential trace element for humans
and domestic animals; however, in high enough doses, zinc
may be toxic. Environmental receptors may be sensitive even
to low doses of zinc. Reported effects of zinc on ducks and
poultry include paralysis, growth reduction, decreased
hemoglobin and hematocrit levels and mortality at hich
concentrations. Local birds observed during waterfowl
observations at the Somers Site showed no symptoms of zinc
toxicity.
2. Three commentors noted that EPA has not researched the
health problems of people in Somers to determine what they
are dying of. Two commentors indicated that most Somers
residents do not die of natural causes and that there is a
high incidence of cancer and heart disease in the community.
EPA Response: EPA's approach to risk assessment at the
Somers Site involved the following steps, 1) determining the
chemical compounds of concern to human health and the
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0100723
environment and the concentrations of those compounds at
Site, 2) determining the possible receptors of those
compounds (i.e., locals residents, wildlife, etc.), 3)
determining the pathways by which contaminants can reach
these receptors, such as in the air, in the water or in
soils, and 4) calculating the risk associated with these
exposures. In order to reduce the risks associated with the
Site, EPA has decided to a) excavate and treat all soils
which are contaminated above health-based concentrations and
which are available for direct contact and b) to treat
contaminated ground water so that it can, in the future, be
used as a drinking water source.
Although it would be possible to conduct a survey to
determine what local residents typically die of, this
information would not assist EPA in developing a cleanup
plan for the Site. It is typically very difficult to
determine a direct cause and effect relationship between
contaminants, such as those in creosote, and human deaths
which may be caused by a number of factors. For example,
certain compounds in creosote are cancer-causing; however,
many other compounds in the environment such as radon,
benzene in gasoline, etc. are also cancer-causing. Personal
habits, such as smoking, and heredity also play a part in
human health. A death from cancer in a community where
creosote has been used may therefore be due to a number of
factors, not simply exposure to creosote. Rather than
attempting to sort out the effect of creosote from other
factors causing illness in the community, EPA has chosen to
remove the exposure pathway by excavating contaminated soils
and treating ground water so that remaining soil and water
is safe for human and environmental contact.
Possible Additional Areas of Contamination
1. One commentor reported that in the late 1950's and early
1960's the ditches near the retort building and along School
Addition Road contained standing creosote. The same
commentor reported that the field below the retort building
was full of creosote when he was a boy and that he found
pools of creosote in the swamp area in the fall of 1988.
The commentor indicated that the estimates of soil to be
excavated may be low because these areas were not
considered. Another commentor indicated that the oil
observed in the ditches in the 50's and 60's was runoff from
oil commonly applied to the dirt roads at that time.
EPA Response: During Site investigations, soil and water
samples were taken in the field below the retort building,
in the swamp area and in the ditch along Somers Road.
Monitoring wells were also installed in these areas as well
as along School Addition Road. Sampling in these areas
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0100734
indicates that creosote contamination above health-based
levels is present within the CERCLA lagoon, in the immediate
vicinity of the old drainage ditch and below a layer of
clean soil across Somers Road from the plant and in the
swamp area. Ground water sampling indicated contamination
only in the areas within and downgradient from the CERCLA
lagoon and in the swamp area.
Based on the information provided by these commentors,
samples will also be taken in the roadside ditch along
School Addition Road to evaluate whether soil contaminant
concentrations are present at levels requiring remediation.
2. One commentor reported a pocket of oil oozing from the
ground south of the boiler by the Somers yacht club as well
as an oil sheen on ground water last fall near the public
water supply pump house. EPA was requested to either add
this area to the Somers Superfund site or designate the area
as a new site.
EPA Response: The entire area around the Somers pump house
and the yacht basin is composed of wood chip fill material
* which is stained in some areas and which would be expected
to release naturally occurring phenolic compounds. The
pocket of oil discovered near the Somers yacht club appears
to be associated with a former rail line which led onto a
pier in Flathead Lake. The oil appeared to be asphaltic in
nature, rather than creosote. Burlington Northern excavated
the area of the ooze and drummed the excavated material for
shipment to a disposal facility.
Because this area is not immediately contiguous with the
Somers site and because the contamination involved appears
to differ from that directly associated with the tie plant,
it is unlikely that the area will be added to the Somers
Superfund Site. However, EPA has initiated the process of
reviewing this area for possible Superfund consideration.
The first step in this review will consist of a Preliminary
Assessment of existing information. If it appears that the
area is of sufficient concern, a limited Site Inspection
will be undertaken. Depending on the severity of the
problems, the area may be eligible for listing on the
National Priorities List or for action under the State
Superfund program.
3. A commentor indicated that another location needing
attention is the northern end of the plant yard area (in a
triangle formed by monitoring wells S-1, S-2, and 86-1)
which was used for treated tie storage and in the area near
Well.86-1 between the slough and the drip track.
EPA Response: The areas mentioned by this commentor were
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0100723
sampled during the Site investigations. A test pit (TP-2
the Somers RI Report) was installed and sampled to
investigate contamination in the former treated wood storage
area. No significant contamination was found in this
sample. The area between the drip track and the slough was
also sampled and monitoring wells were installed in this
area. Mo ground water contamination was detected.
4. The FLPA recommended that EPA include the spur line on the
west side of the tie plant property in the areas to be
excavated and treated.
EPA Response: Although the spur line was not reportedly
used to carry treated ties, the soil and ballast under the
track is stained. Samples will be taken to evaluate whether
soil contaminant concentrations are present at levels
requiring remediation.
Public Participation Process _;
1 . There were a number of requests that EPA extend the public
comment period based on the length of the documents
available for review and the new information contained in
these documents.
EPA Response: The Remedial Investigation Report was
released to the public in April 1989, although most of the
information contained in the report had previously been
released. The Feasibility Study Report and EPA proposed
plan were released to the public on May 18, 1989. EPA held
a public meeting in Somers on June 6, 1989 to receive any
questions or comments on these documents. A second public
meeting was held in Paradise on June 21, 1989, and a third
meeting was held in Somers on July 27, 1989. The comment
period initially allowed 30 days for comment, but was
extended on two occasions; with the extensions, the comment
period ended August 3, 1989.
2. The Flathead Lake Protection Association and the Clark Fork
Coalition recommended that the Somers Site not be removed
from the Superfund National Priorities List. The Clark Fork
Coalition also suggested that, if the Somers Site is removed
from the National Priorities-List, a mechanism be developed
to ensure that EPA retains supervisory authority over the
site remediation.
EPA Response: The Somers Site was proposed for the
Superfund National Priorities List in 1984, however the Site
was never finally added to the List. In 1988, EPA proposed
to remove the Site from the proposed NPL because it is a
regulated facility under the Resource Conservation and
Recovery Act which also has the authority to handle the
i
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0100736
cleanup. EPA will not retain such sites on the NPL unless
potentially responsible parties (PRPs) such as BN are unable
or unwilling to conduct the cleanup. EPA has not yet taken
final action to remove the Site from the NPL.
Upon completion of this Record of Decision, EPA will offer
PRPs the opportunity to conduct the cleanup. If the PRPs
agree to do the work, a Consent Decree which specifies the
terms of this agreement will be signed and filed in court.
In order for EPA to continue to oversee the cleanup as a
Superfund action, the PRPs must agree in the Consent Decree
to pay EPA's oversight costs. The Site will then be removed
from the proposed NPL, but the cleanup will be handled as a
Superfund action under EPA oversight. If the PRPs refuse to
do the cleanup, then EPA must repropose and finalize the
Site on the NPL in order to conduct the work itself using
the Superfund.
3. The Clark Fork Coalition and the Flathead Lake Protection
Association suggested that the PRP should be required to
fund the position of a citizens' technical advisory in'the
event that the present Technical Assistance Grant expires or
is terminated due to the removal of the Somers Site from the
Superfund National Priorities List or for any other reason.
The Coalition recommended that such a technical advisor have
all rights and privileges of access to data and information
as those available under the EPA Technical Assistance Grant
program.
EPA Response: If and when the Somers Site is removed from
the proposed NPL, the Flathead Lake Protection Association
will no longer be eligible for the Technical Assistance
Grant. By statute, such grants are only available at sites
on the National Priorities List. The Potentially
Responsible Party may be willing to fund a similar technical
advisor in the event that the EPA Grant is terminated,
however, this is not a legal requirement under CERCLA. If
such a position were funded, EPA would provide the same
rights and privileges of access to the advisor as are
available to all members of the public.
4. Paradise residents asked how the public could affect the
final EPA decision for site cleanup and whether it was
necessary for the public to develop a different alternative
or whether their feelings would make a difference.
EPA Response: Community acceptance is an important factor
which may modify or change EPA's evaluation of the best
alternative for site remediation. Because of significant
public opposition received to EPA's proposal to transport
Somers soils to Paradise for treatment, EPA has instead
decided to conduct treatment of these soils at the Somers
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Site.
5. Comraentors asked what the public's recourse is if the EPA or
MDHES decisions are ngt what the public wants or if the
selected remedy does not solve the problem.
EPA Response: MDHES permit decisions aVe subject to a
formal appeal procedure outlined in the State RCRA
regulations. EPA Superfund decisions are not subject to a
formal appeal procedure, but the public will be provided an
opportunity to review the final Record of Decision for the
Somers Site and will be asked to comment on the Consent
Decree which is developed to implement the remedy. The
Consent Decree will also contain the scope of work outlining
the work to be performed. EPA may change these documents
based on public comments. If at some future time, it is
apparent that the selected remedy will not adequately solve
the problems at the Site, EPA may select a new alternative
or change somewhat the selected alternative. In this case,
depending on the significance of the proposed change, the
public may again be asked to comment.
6. A Paradise resident commented that Somers residents should
set up talks between themselves, the regulatory agencies and
BN.
EPA Response: After the close of the comment period, EPA
received a petition from 41 Somers residents requesting EPA
to set up additional meetings to discuss issues of concern
to the Somers community. In 'a letter to all Somers
residents, EPA agreed to set up regular meetings and
requested that the community organize an informal citizens
advisory committee to meet wi'th the agency and BN. A Somers
resident is coordinating this activity.
Other Comments
1 . Several commentors expressed concerns that the weeds growing
on the tie plant property may pose a fire hazard to the town
of Somers. Legal action against BN was threatened.
EPA Response: Burlington Northern indicated that they have
contacted the local weed district and have sprayed their
property according to local guidelines.
2. A commentor asked why the Railroad cars are back at the
Somers Site.
EPA Response: Burlington Northern indicated that the spur
line must be used in order for the railroad to be allowed
keep the line open. For this reason, railroad cars are
•periodically stored on the spur line at the Site.
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3. A conunentor asked what the next steps are in the Superfund
process at the Somers Site, including when the Consent
Decree will become effective and when field work will begin
at the Site.
EPA Response: EPA expects to send a Special Notice letter
• to the Potentially Responsible Parties (PRPs) at the Site
shortly after finalizing this Record of Decision. The
letter will offer the PRPs the opportunity to conduct the
cleanup and will mark the beginning of a four month
negotiation period in which EPA and the PRPs work toward an
agreement on the work to be performed and the language of
the Consent Decree which will enforce the agreement. Once
the Consent Decree is signed, a 30 day public comment period
will be held before the document is filed in court. The
entire negotiation, comment period, and filing process can
take 6 months or more. It is therefore expected that actual
field work will not begin until the spring or summer of
1990.
4. The Somers Water District noted that a new sewer system is
planned for the town and the route of the sewer line may
cross BN property.
EPA Response: The work plan for the Site cleanup should be
completed in the winter or spring of 1990. Once the work
plan is finalized the Water District should have a better
idea of where treatment units will be placed so that the
best sewer line location can be determined.
5. A Somers resident commented that, if the proposed cleanup
alternatives result in a site which is suitable for
revegetation, BN should be encouraged to donate the land to
the community of Somers for use as a park or a walking,
biking area. The conunentor noted that presently, Somers
children hike through the property to shorten their walk to
school.
EPA Response: The ultimate disposition of the tie plant
property will be up to Burlington Northern, but will be
limited by restrictions on the deed to the property housing
the closed RCRA impoundments and possibly, depending on the
degree of treatment achieved, the land treatment unit. Such
deed restrictions are intended to protect the cover placed
on a unit housing hazardous waste to ensure that the
materials are not disturbed. BN must also complete up to 30
years of monitoring and post-closure care of the RCRA
impoundments. These restrictions may limit future use of
the property.
In order to prevent children from gaining access to
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01007:9
hazardous areas of the Site, the treatment units will be
fenced and any buildings or materials at the Site will be
secured.
6. Both BN and the FLPA commented that disturbed wetlands, such
as the slough and swamp areas should be restored.
EPA Response: EPA has required the restoration or
replacement of wetlands in the Record of Decision. These
activities will be conducted in coordinated with the U.S.
Department of the Interior.
7. A commentor asked how many gallons of waste were released
into the environment.
EPA Response: An accurate estimate of the amount of waste
released to the environment is not possible. The average
rate of wastewater dischargevfrom the plant was 350 gallons
per day. However, this water was not always released to the
environment. Originally, this water was used as makeup .
water for the boiler. Drippage and sludges from the retort
was reported to amount to approximately 1,000 pounds every
1.5 to 2 years. In recent years, sludges were disposed of
off-site at a commercial RCRA disposal facility. No records,
exist of past disposal practices, although workers recall
that some materials were used to patch holes and oil local
roads.
8. A commentor expressed distrust of BN and the regulatory
agencies, noting that BN did not follow the approved plans
for closure of the RCRA impoundments at Somers. The old
liner in one impoundment was supposed to have been steam
cleaned, but this was not done.
EPA Response: The MDHES-approved closure plan for the RCRA
impoundments at the Site allowed BN to salvage a secondary
liner in one impoundment which was not in contact with any
wastes. Prior to storage of this material, BN was to
inspect the liner and brush and steam clean it as needed to
ensure that no visible residue remained. During the closure
activities the secondary liner was found to be intact and
undamaged. Visual inspection showed no evidence of
contamination or residues, therefore the liner was not steam
cleaned.
9. The Somers Water District expressed concerns that the water
mains which run through the tie plant may freeze and rupture
again. The District would like to see the mains relocated.
EPA Response: EPA agrees that the water mains should be i
. moved as soon as possible. BN has indicated a willingness
to conduct that part of the water main excavation which will
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0100740
occur through the known contaminated area below the retort
building to ensure that any hazardous wastes generated are
properly handled. If the line is placed in a contaminated
area, the pipe must be protected from contamination. EPA
would oversee this work. However, if replacement of this
line occurs before the final remedial action at the Site is
undertaken and soils in the area of the relocated main must
be excavated, the new line may have to be removed and
replaced.
10. Commentors asked whether and when the tie plant structures
will be demolished. Residents are concerned about site
safety. The same commentor asked how the demolished
buildings would be removed from the Site.
EPA's Response: The Site buildings are eligible for the
National Register of Historic Places. EPA is therefore
required to coordinate with the State Historic Preservation
Office (SHPO) to ensure that appropriate mitigation measures
are taken to protect or document these resources during
remedial action. EPA has recommended that the retort
building must be demolished in order to access contaminated
soils beneath the building, however, SHPO concurrence must
be obtained before demolition. Once the buildings are
demolished, the material will be transported from the Site
by truck. Security at the Site will be improved to prevent
access to buildings at the Site.
11. Two commentors expressed concern that truck traffic and
chaos during cleanup will adversely affect the roads, town
and people of Somers but that this can be minimized by
conducting the cleanup in as short a time as possible.
EPA Response: It is anticipated that maximum activity at
the Site will occur during a period of a few months when
soils are excavated and backfilled and the various treatment
units and the temporary soil storage unit are constructed.
After that time, maintenance of the treatment units should
provide little disruption to the town.
D. REMAINING CONCERNS
Issues and concerns that EPA was unable to address during
remedial planning activities include the following:
1. It is not certain that land treatment will reduce
contaminant concentrations in soils to levels sufficiently
low to allow unlimited future use of the property. If
residual concentrations are reduced to background, no
postclosure restrictions on the use of the property will be
imposed. However, if residual concentrations are above
background, postclosure monitoring and restrictions on the
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use of the property will be necessary.
2. It is also not possible to determine whether the land
treatment unit will need to be closed with an impermeable
cap or whether it can be covered with a vegetative cap. If
residual soil contaminant concentrations are reduced to
health-based levels and any leachate collected in the
treatment unit contains concentrations within EPA's required
ground water cleanup levels, then a vegetative cap will be
allowed. If this is not the case, an impermeable cap will
be necessary.
3. Until pilot testing is completed, it will not be possible to
determine whether the selected or a contingency remedy will
be undertaken at the Site.
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SUMMARY OF
COMMUNITY RELATIONS ACTIVITIES AT THE
BURLINGTON NORTHERN (SOMERS PLANT) SUPERFUND SITE
Community relations activities conducted at the Burlington
Northern Somers Site ("the Site") to date have included:
o EPA and the Montana Department of Health and Environmental
Sciences (MDHES) conducted interviews with members of the
community to determine issues of concern related to the Site
and to identify effective methods for the agencies to
respond to concerns and communicate with the public.
Interviews were conducted in 1985 and 1988.
o EPA developed a Community Relations Plan in 1985 and revised
the plan with the assistance of MDHES in 1989.
o EPA issued Press Releases at the following times:
o 1984 - announcing EPA's proposal to add the Somers site
to the National Priorities List.
o 1985 - announcing a public comment period on the Remedial
Investigation/Feasibility Study (RI/FS) work plan and EPA's
administrative order on consent with BN.
o 1987 - announcing a public comment period on an amendment
to the RI/FS work plan.
o 1989 - announcing an extension to the comment period on
EPA's proposed plan.
o EPA established a Site information repository in 1985 and,
in 1989, an Administrative Record file at the Somers Central
School Library.
o EPA issued a fact sheet in 1985 and 6 updates on Site
activities between 1985 and 1989.
o EPA released the following documents for comment:
o 1985 - Administrative Order on Consent and RI/FS project
plans.
o 1987 - Amendment to the RI/FS work plan.
o 1989 - RI/FS reports and EPA proposed plan.
o EPA held public meetings at the following times:
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o 1985 - to update the community prior to commencement of
work under EPA oversight.
o 1985 - to discuss Administrative Order on Consent and
RI/FS project plans.
•o 1987 - to update the public on EPA activities at the
site. Meeting was held immediately following a State RCRA
public hearing on closure plans for RCRA-regulated
impoundments.
o 1989 - to discuss the preliminary findings of the RI and
to review cleanup technologies under consideration.
o 1989 - three public meetings were held to discuss the EPA
proposed plan.
EPA twice provided extensions to the public comment period
on the proposed plan.
EPA funded a Technical Assistance Grant (TAG) for the
Flathead Lake Protection Association in 1988. Regular
communication was maintained with the TAG consultant.
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