:'q \	Proposed Plan for	DEQ
M/ Libby Asbestos Site Cleanup
Libby and Troy Residential and Commercial Properties, Parks and Schools,
Transportation Corridors, and Industrial Park
May 2015
Introduction
The public is invited to review and comment on this
proposed plan to determine remedial action at the
Libby Asbestos Superfund Site (the Site] located in
and around Libby and Troy, Montana.
The proposed plan addresses five of eight areas at
the Site. Remedial action has already been
completed at Operable Unit 1 (the former Export
Plant, now Riverfront Park in Libby] and Operable
Unit 2 (former Screening Plant], Operable Unit 3 (the
former Libby vermiculite mine and forested areas]
will be addressed in a separate proposed plan.
Investigation and cleanup are being conducted by
the U.S. Environmental Protection Agency (EPA] in
consultation with the Montana Department of
Environmental Quality (DEQ] under the federal
Superfund law.
Because long-term management tools, otherwise
known as institutional controls, are instrumental to
the cleanup, we have divided this document into
three sections. Part One provides background and
explains alternatives considered for the construction
portion of the remedy. Part Two explains why waste
will remain at the site and provides additional
information about institutional controls. Part Three
summarizes EPA's and the state's preferred remedial
alternative.
As lead agency, EPA is required to issue a proposed
plan and solicit public input. Citizens can provide
comment during a public comment period, May 8 to
July 8, 2015, or atthe public meetings.
then select the preferred cleanup alternative, modify
it, select another alternative, or develop new
alternatives if public comments warrant or if new
information is presented. That selection will be
presented in a written record of decision.
We want your input!
Public comment period: May 8 to July 8, 2015
During the comment period, EPA is accepting
comments on this proposed plan, as well as all
supporting documents, including the remedial
investigation, feasibility study and draft human
health risk assessment Mail or email comments to:
Rebecca Thomas
Project Manager
U.S. EPA Region 8 (EPR-SR]
1595 Wynkoop Street
Denver, Colorado 80202
EPALibbyPlan@epa.gov
Mark your calendars!
EPA and MDEQ are hosting two public meetings
to present this proposed plan and accept
formal public comment:
7-9 p.m. Wednesday, May 20, Kootenai Senior
Center, 304 Third Street, Troy
7-9 p.m. Thursday, May 21, City of Libby's
Ponderosa Room, 952 E. Spruce St.
EPA and MDEQ are also hosting a workshop in
conjunction with the county's Asbestos Resource
Program, Libby Technical Advisory Group and
Community Advisory Group to evaluate input
received on the preferred institutional controls:
7-9 p.m. Tuesday, June 30, City of Libby's
Ponderosa Room, 952 E. Spruce St.
See page 15 for information about how to obtain
site documents.
Atthe end of the comment period, EPA will consider
and respond to all comments provided. EPA may
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Part One: Cleanup of Libby Amphibole Asbestos
Understanding the Superfund
Process
Removal Program
EPA's Removal Program has been conducting
investigations and removal actions addressing Libby
Amphibole asbestos (LA] since 2000. This has
allowed immediate reduction of human health risks
while the science has evolved to make the best long-
term cleanup decisions possible.
EPA has removed major sources of LA in and around
Libby and Troy, investigated thousands of properties,
and conducted removals at more than 2,000 private
homes and properties. Removals include the former
export plant, former screening plant, Riverfront Park
and boat ramp, rail yard, golf course, the Flyway,
schools and school yards, creek banks and other
public areas. EPA has now removed more than one
million cubic yards of impacted soil and more than
30,000 cubic yards of contaminated building
material. Removal actions will continue until a record
of decision is signed, remedial design is complete,
and remedial action begins.
Remedial Program
The proposed plan is part of a deliberative process
that occurs under EPA's Remedial Program and
includes everything from site discovery through
deletion. Remedial investigations were completed
in 2014. Investigation data from 2000 to 2014
were used in the site-wide risk assessments and
feasibility study.
What Are Response Actions?
Response Action = cleanup conducted under
EPA's Removal or Remedial Program -
includes removal and remedial actions
Removal Action = cleanups conducted since
2000 under EPA's Removal Program
Remedial Action = future cleanups to be
conducted after a record of decision is issued
under EPA's Remedial Program; includes
institutional controls and monitoring
Remedial Action Level = level at which
cleanup is required
The Superfund Process
Removal
Program
Addresses immediate
threat to health
Action Memo
Removal Action

Remedial
Program
Addresses long-term
threat to health
Preliminary Assessment/
Site Inspection
Remedial Investigation
Risk Assessment
Feasibility Study
Proposed Plan
Implement
Interim
Institutional
Controls
Record of Decision
Remedial Design
Develop Institutional
Controls
Remedial Action
Implement Institutional
Controls
Operation and
Maintenance
Maintain Remedy and
Institutional Controls
Site Deletion
Site Background

LA contamination in Libby originated with
operations at the nearby former Libby vermiculite
mine, most recently owned and operated by W. R.
Grace Company. LA is co-located with vermiculite
deposits at the mine. Vermiculite ore and
amphibole asbestos were valuable commodities
transported from the mine to the former Screening
Plant and to local and nationwide processing
facilities. Some of the ore was processed by heat
expansion and exported to market via truck or rail.
From the early 1960s to 1990, the Export Plant
was used for stockpiling and distributing
vermiculite concentrate to Grace's plants and
customers nationwide. Expansion operations
stopped before 1981, but milled ore was bagged
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and exported until 1990. As a result of these
processes, contamination was widely distributed.
In November 1999, in cooperation with the federal
Agency for Toxic Substances and Disease Registry
and DEQ, EPA began an emergency response action
to protect public health. This response action
continues today. Because of unacceptable risk, the
Site was added to EPA's National Priorities List in
October 2002.
Throughout the process, interim removal actions,
such as removal of LA-containing materials, soil,
insulation and debris, were performed in
conjunction with investigation activities. The
removals provided protection while remedial
investigations, risk assessments, and feasibility
studies were being conducted. Since 2000, work has
included numerous investigations, pre-removal
sampling, removals, reports, and decision
documents. Individual property assessments are still
continuing in Libby and Troy.
EPA's Administrator determined on June 17, 2009
that conditions at the Site constituted a public health
emergency. This was the first time that EPA made
such a finding under the federal Superfund law. In
making this determination, EPA recognized the
serious health impacts from LA contamination in
Libby, and made it possible for the U.S. Department
of Health and Human Services to provide asbestos-
related medical care to eligible Libby and Troy
residents. EPA is continuing to identify and conduct
activities needed to complete the remedial action so
that the public health emergency may be lifted.
Site Characteristics
The Site is roughly 200 square miles and includes
Libby, Troy, the former Libby vermiculite mine, and
other areas in Lincoln County. The Site has been
divided into eight operable units, five of which (4, 5,
6, 7, and 8} are included in this proposed plan.
Remedies have already been selected for Operable
Unit 1 (Riverfront Park] and Operable Unit 2 (former
screening plant]. Operable Unit 3, the former Libby
vermiculite mine, is being addressed separately.
Location of Operable Units Addressed in this Proposed Plan (4, 5, 6,1, and 8)
Operable Unit 6. All Burlington Northern Santa Fe
railroad property in and between Operable Units 4
and 7, including rights-of-way and rail yards
Former Libby vermiculite mine
(Operable Unit 3 not addressed
by this proposed plan)
Operable Unit 7. Residential, commercial,
and public property in and around Troy
(about 20 miles west of Libby)
Operable Unit 5, Industrial
Park with 400 acres of
industrial property (former
Stimson Lumber Mill)
Operable Unit 4. Residential,
commercial, industrial, and public
properties in and around Libby
Operable Unit 8, U.S., state
and county route rights-of-
way within and between
Operable Units 4 and 7
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What are the Sources of Libby
Amphibole Asbestos?
The former Libby vermiculite mine is the source for
LA contamination. LA is present in vermiculite
deposits that were mined by Grace and resulted in
significant contamination. Use or transport of
LA-containing vermiculite also created secondary
sources. These include contaminated building
materials such as vermiculite insulation;
contaminated soil in gardens, yards or roadways; and
indoor dust that results from contaminated soil or
attic insulation.
Who is Exposed and How?
Residents, workers, trades people and recreational
visitors may be exposed through inhalation of.
¦	outdoor (ambient] air
¦	outdoor air during soil disturbance
¦	indoor air after disturbance of contaminated
building materials or dust
¦	indoor air under passive conditions
(e.g., watching television]
Assessing Risk
More than 150 types of activity-based samples have
been collected to evaluate exposures. These types of
activities included sweeping and vacuuming
disturbing yard soil, raking and mowing bicycling
and driving on roads, and worker activities. Data
from more than 4,600 samples (from activity-based
and outdoor air samples] have been used in the risk
assessment to evaluate LA exposure.
Adverse effects from exposure to LA include cancer
and non-cancer effects:
¦	Cancer effects are primarily lung cancer and
mesothelioma. EPA considers a lifetime risk for
developing cancer between 1 per 10,000 and
1 per million to be within EPA's acceptable range.
¦	Non-cancer effects include asbestosis and
abnormalities in the membrane of the lungs (such
as pleural thickening]. Calculation of non-cancer
risk for an exposure pathway results in a value
known as a hazard quotient. The sum of these
quotients from multiple pathways is known as a
hazard index. If the cumulative hazard index is
less than or equal to 1, remedial action is
generally not needed.
The 2014 draft site-wide human health risk
assessment estimates LA exposure based on current
or reasonably anticipated future conditions.
Highlights include:
¦	Levels of LA in outdoor air are now equal to those
seen in other Montana cities and are up to
100,000 times LOWER today than during
previous mining and processing operations.
¦	LA is present in background soil in the Kootenai
Valley, but concentrations are low and exposures
are unlikely to pose unacceptable risks.
¦	It is possible to live without unacceptable risks
from LA exposure in most of Libby and Troy, but
unacceptable risks remain at properties where
LA remains above trace concentrations at
residential properties and has not been
addressed.
¦	Investigations and removals have been effective
at identifying and mitigating sources of interior
LA.
¦	People who actively disturb LA-contaminated
vermiculite indoors may incur unacceptable risk.
Handling this vermiculite requires protective
equipment (such as a respirator],
¦	Residents and outdoor workers who disturb
LA-containing yard soil can potentially be
subjected to unacceptable risks for some types of
soil disturbances.
¦	Some short-term exposures to higher
concentrations of LA contribute much more to
overall risk than do some long-term exposures to
lower concentrations of LA.
¦	It is possible to reduce exposure and risk by
lowering LA levels where disturbances are
expected (e.g., removing yard soil with LA],
Ecological Risk
The 2014 site-wide ecological risk assessment
evaluated data for risk to fish, insects, amphibians,
mammals, and birds. Risks are highest in Operable
Unit 3, where concentrations of LA are highest The
ecological risk assessment indicates that LA
exposures, even in Operable Unit 3, are likely to
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have minimal to no adverse effects on plants and
animals. Thus, remedial alternatives presented in
the proposed plan focus solely on human health
risks from exposure to LA.
Prior Response Actions
As discussed in Site Background, EPA began
emergency response in 1999. Four property types
have been used in the feasibility study evaluations
and in the development of the preferred alternative
for this proposed plan. Below is a short description
of each property type and the status of previous
response actions. A detailed description of the
investigations and response actions for each is
provided in Appendix A of the feasibility study.
¦	Residential/Commercial Properties. These
properties are located in Operable Units 4 (Libby)
and 7 [Troy], There are about 6,500 residential/
commercial properties in Libby and 1,500
properties in Troy. Since 2002, EPA has
investigated more than 6,900 properties and
completed removals at 2,043 of those properties.
EPA expects to complete investigations at the
majority of properties where access has been
granted in 2015. In addition, EPA anticipates
additional investigations at fewer than 100
properties to ensure that past decisions are
consistent with the preferred remedy. Remedial
action may be required at between 300 and 500
properties. Owners of many of the remaining
properties have refused access or have not
responded to repeated investigation requests.
¦	Industrial Park. This property is located in
Operable Unit 5 (former Stimson Lumber Mill).
Investigation began in 2001 and removal ended
in 2013. Since 2005, there have been numerous
activity-based sampling studies (mowing,
raking child play, motorcycle, bicycle and
outdoor worker). Part of Industrial Park is used
for recreation, including a motocross track,
fishing pond and recreational hiking trail along
Libby Creek. The remedial investigation was
completed in 2013 and removals were
completed where needed.
¦	Transportation Corridors. These properties
encompass 42 miles of rail line, rights-of-way, and
rail yards (Operable Unit 6), as well as 30 miles of
U.S. 2, Montana 37, and Farm to Market and River
roads (Operable Unit 8). They have been
investigated and removals conducted, where needed.
¦ Parks and Schools. These properties are located
in Operable Units 4 (Libby) and 7 (Troy). There are
12 city and county parks in Libby and seven in
Troy. Park investigations occurred between 2001
and 2006. Removals were completed in 2006 and
included contaminated soil (J. Neils Park) and
materials inside structures (Pioneer, Cemetery,
and Fireman's parks). Libby has four public
schools and two private schools, and Troy has two
public schools. Investigations and removal work at
the majority of schools were completed in 2006.
Investigation was completed at Morrison
Elementary in 2014 with no removal needed.
Past exterior response actions to reduce exposure
from disturbance of soil have included excavation of
LA-containing soil, to depths up to 3 feet in some
instances, and clean soil replacement. Interior
response actions to reduce indoor exposures have
included removal or encapsulation of vermiculite
insulation and other LA-containing building
materials and interior cleanings. The human health
risk assessment has shown these past response
actions have been effective in reducing LA
exposures.
Remedial Action Objectives
Remedial action objectives provide a general
description of what a cleanup will accomplish, and
are used to develop the cleanup options described in
the next sections. They include:
1.	Reduce exposures from inhalation of LA during
disturbance of contaminated soil so that risks
are below EPA's acceptable level; and
2.	Reduce exposures from inhalation of LA from
disturbance of contaminated building materials
so that risks are below EPA's acceptable level.
These objectives consider how a cleanup can be
protective of human health and the environment
based on property types and current and reasonably
anticipated future land use.
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Alternatives Considered for Remedial Action
EPA evaluated a variety of remedial technologies and process options to develop remedial alternatives. These
alternatives are described in EPA's feasibility study. Seven alternatives were screened for contaminated soil and
six for contaminated building materials (see the table below]. Each was assessed to determine its ability to protect
human health and the environment by overall effectiveness, implementability and cost. Four alternatives for soil
(S2, S3, S4, and S7] and three for building materials (B2, B3, and B6] were eliminated from further consideration.
The remaining alternatives were retained for detailed analysis, including no action/no further action which are
required as a baseline for comparison.
Alternatives Screened for Effectiveness, Implementation and Cost
Contaminated Soil Alternatives (S)
Contaminated Building Material Alternatives (B)
SI
¦ No action/No further action*
B1
¦ No action/no further action*
S2
¦	Institutional controls
¦	Access controls and monitoring
B2
¦	Institutional controls
¦	Access controls and monitoring
S3
¦	Permanent relocation
¦	Institutional controls
¦	Access controls and monitoring
B3
¦	Permanent relocation
¦	Institutional controls
¦	Access controls and monitoring
S4
¦	Covering of contaminated soil without removing
contaminated soil
¦	Institutional controls and monitoring
B4
¦	Encapsulation of accessible contaminated materials
¦	Interior cleaning
¦	Institutional controls and monitoring
S5
¦	Covering of contaminated soil
¦	Limited excavation of contaminated soil to allow cover
¦	Disposal of excavated soil at the former vermiculite mine
¦	Institutional controls and monitoring
B5
¦	Removal of accessible contaminated materials
¦	Disposal of materials at permitted facility
¦	Encapsulation of remaining contaminated materials
¦	Interior cleaning
¦	Institutional controls and monitoring
S6
¦	Partial excavation** of contaminated soil
¦	Backfill with uncontaminated fill
¦	Disposal of excavated soil at the former vermiculite mine
¦	Institutional controls and monitoring
B6
¦	Complete removal of contaminated materials
¦	Disposal of materials at permitted facility
¦	Interior cleaning
¦	Institutional controls and monitoring
S7
¦	Complete excavation of contaminated soil
¦	Backfill with uncontaminated soil
¦	Disposal of excavated soil at former vermiculite mine
¦	Institutional controls and monitoring

Alternatives highlighted in green retained for detailed analysis.
*Required to move forward by Superfund law as a baseline for comparison.
**6 to 36 inches in depth depending on constraints and concentrations of LA.
All alternatives, except no action, would include institutional controls. Institutional controls would protect the
remedy by ensuring that human activity does not cause damage and restrict uses or activities that could pose an
unacceptable exposure. One example is a permit for soil excavation to prevent re-contamination from soil at
depth. The permit would minimize exposure to LA by requiring potentially-contaminated soil to be properly
handled and disposed of. Institutional controls could also establish an educational program about risks from
exposure to LA above certain levels. This could reinforce the importance of protecting the remedy, and what to do
if new sources are discovered or if the remedy is damaged. Selected institutional controls would be documented
in the record of decision or in the remedial design in consultation with EPA, DEQ, Lincoln County, cities of Libby
and Troy, and the public. Operation and maintenance activities are also required to ensure long-term
effectiveness of the remedy.
The tables below summarize the similarities and differences between alternatives. Costs estimates are presented
for comparison of alternatives. Actual costs range from 30 percent lower to 50 percent higher than costs
developed for the feasibility study.
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How Do Remedial Alternatives for Contaminated Soil Compare to One Another?
Considerations
SI: No
further
Action
S5: Limited excavation/disposal, covers,
institutional controls, and monitoring
S6: Partial excavation/disposal, backfill,
institutional controls, and monitoring
Excavation?
None
Limited to allow covers at grade.
Excavation of accessible contaminated soil.
Covers?
None
Use soil from non-local sources.
None, except for backfill (non-local sources).
Exceptions?
None
Where covers or excavations are not possible, due to obstructions (e.g., structures), obstructions
would be kept in place to prevent exposure. Institutional controls will be needed to address LA if
structures are removed.
Relocation?
None
Residents temporarily relocated and businesses temporarily closed during cleanup.
Disposal?
None
Excavated soil taken to the former vermiculite mine.
Re vegetation?
None
Revegetated or otherwise restored to pre-remediation conditions.
Institutional
Controls?
None
Protect remedy, restrict or prevent uses or activities that could pose unacceptable exposure, require
management of LA where land use changes or inaccessible LA becomes accessible, and provide
awareness of risks from exposure to LA.
Monitoring and
Maintenance?
None
Inspection and repair of covers in public use
areas.
Inspection and repair to backfill over delineation
marker barriers in public areas.
Cost Estimate?*
$550,000
$35,810,000
$53,860,000
Timeframe?
None
3 years of construction.
4 years of construction.
*Present value costs were developed for the estimate of each alternative per EPA policy. Present value cost represents the
amount of money that, if invested in the initial year of the alternative at a given rate, would provide the funds required to make
future payments to cover all costs associated with the alternative over its planned life.
How Do Remedial Alternatives for Contaminated Building Materials Compare to One Another?
Considerations
Bl: No
further
action
B4: Encapsulation, interior cleaning,
institutional controls, and monitoring
B5: Partial removal/disposal, encapsulation,
interior cleaning, institutional controls, and
monitoring
Removal?
None
None.
Accessible contamination removed by vacuum or
other mechanical means.
Encapsulation?
None
In-place sealing/covering of all accessible
materials with high performance coating to
prevent release of LA.
In-place sealing/covering of remaining accessible
materials with high performance coating to
prevent release of LA.
Cleaning?
None
Interior cleaning after removal or encapsulation. Results of air monitoring must meet remedial
clearance criteria.
Relocation?
None
Residents temporarily relocated and businesses temporarily closed during cleanup.
Disposal?
None
None.
Contaminated materials disposed of at Lincoln
County Landfill asbestos cell.
Institutional
Controls?
None
Protect remedy, restrict or prevent uses or activities that could pose unacceptable exposure, and
provide awareness of risks from exposure to LA.
Monitoring and
Maintenance
None
Post-construction inspection and repair at encapsulation sites in public areas.
Instruction
None
Maintenance manual would include instructions on how to address contaminated materials left in
place if future disturbance is required.
Cost Estimate?*
$330,000
$9,730,000
$9,840,000
Timeframe
None
1 year of construction.
1 year of construction.
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Part Two: Long-Term Management of LA
Institutional controls are an important part of the remedy and are required with all alternatives to manage future
releases of LA or "waste left in place." LA will remain at the Site and could become a new source of exposure after
the construction portion of the remedy described above is implemented. It is not practical to remove all LA that is
sealed behind indoor walls or to excavate all LA that is in soil. Contaminated soil may be left beneath the surface
after contaminated soil is removed. LA may also remain in wall cavities and other interior locations that are
inaccessible.
A combination of several institutional controls will be needed to manage the variety of activities that could disturb
potentially contaminated soil or building materials. Examples of disturbances include homeowners digging or
excavating for a fence or septic tank; contractors constructing new roads and buildings, and municipal workers
laying utility lines.
Because EPA conducts cleanup based on current or reasonably anticipated future land use, controls will also be
needed to track land use changes over time to determine whether a property requires a more stringent cleanup
standard (e.g., an undeveloped property becomes a residential property]. Additionally, controls will be needed to
manage properties or portions of properties that have not been screened. This is because some properties or
portions of a property were infrequently used at the time of screening or because the property owner denied
access.
Objectives of the Institutional Controls
To ensure that the remedy remains protective and that risk remains below EPA's level of concern, the objectives
of the institutional controls are to:
1.	Prevent LA fibers that may remain beneath soil covers or at undeveloped properties from becoming a future
source of unacceptable exposure.
2.	Prevent LA fibers that may remain in inaccessible building materials from becoming a future source of
unacceptable exposure.
3.	Track changes in land use and develop a notification system to ensure that property owners, prospective
property owners and workers are aware of remaining or potential LA and institutional control requirements.
Institutional Controls
Some of the institutional controls considered have already been implemented at the site to manage potential
encounters with LA. EPA and DEQ recognize that there maybe other institutional controls that may be useful at
the Site. We encourage input to develop a comprehensive program of controls that will work best for the
communities.
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Institutional Controls Considered for the Libby Site
Institutional
Control
Purpose
Additional Information
UDIG program
Ensure asbestos information is provided to property
owners before they dig.
Coordinate with asbestos support program regarding
planned excavations, presence of LA, and
recommended precautions.
Montana Dept. of
Transportation
permit
Prevent exposures in transportation corridors by
requiring permits for construction or maintenance of
highway rights-of-way.
Would properly manage and dispose of waste
encountered on, over, or under the right-of way,
including landscaping.
Asbestos support
program
Provide resources and education to help the community
manage exposures and risk.
Would include designated program staff and contact
information for the public.
Educational
program for
managing
exposure
Provide educational tools to help the public avoid
exposure and cross contamination with an emphasis on
best management practices when potentially encountering
LA.
Examples include a handbook, school programs,
external education, tools for newcomers, ads, materials
for those who obtain hunting/fishing licenses and/or
city workers conducting excavation.
Property status
database
Identify and track cleanup status of properties and known
areas of contamination; also identify land use.
Searchable database.
Update codes,
ordinances, and
regulations
Ensure that an asbestos support program is involved with
existing application/approval process to provide
information for actions that may encounter LA.
Would include updates to control of air pollution,
wastewater treatment, solid waste, general health and
subdivision regulations.
Open space
recreation initiative
Prevent and/or reduce dust on new and existing trail
systems through use of appropriate trail coverage.
Would reduce potential exposure to LA by paving or
hardscaping high-use areas.
Public nuisance
ordinance
Prohibit activities that could result in excessive public
exposure to LA.
Would enforce existing nuisance ordinance.
Permit for
disturbance of soil
or building materials
A new permit to manage disturbance of contaminated
building materials and soil within the Superfund Site
(separate from other existing city and county permits).
Would provide access to information and potential
resources such as clean fill and topsoil, personal
protective equipment, and free disposal.
Contractor
certification
Ensure training of contractors and others who may
disturb LA on how to manage contamination.
List of certified contractors would be available to the
public.
Property notices
Alert record searchers of property cleanup status by
placing documentation in public land records.
Would be used to flag properties where investigation
or cleanup has not been completed.
Advisories
Warn potential land users of existing or pending risk
associated with use.
Could include internet, newspaper, mailings or signs
to notify general public, search and rescue workers,
firefighters, loggers, etc.
Other Institutional Controls That May Be Useful
Zoning
Prohibit certain activities based on the property location
and contamination status.

Easement or
Covenants
Provide information to property owners about how they
can place voluntary environmental easements or
covenants on their property; would prevent land use
changes
Would be voluntary, so not effective as an
institutional control.
Modify existing
building permits
Modify existing building permits to include enforceable
requirements for disturbance of LA contaminated
building materials throughout the Superfund Site.
Would allow enforcement of building permits where
LA might be disturbed at properties beyond city limits.
Property
transaction
disclosures
Ensure that asbestos information associated with a
particular property is shared with a prospective
purchaser during a property transaction.
Property notices listed above may achieve a similar
result.
Asbestos program
notification
Asbestos support program would provide information
about asbestos for specific properties.
Would not be enforceable.
Green shading indicates the control is already fully-implemented at the Site.
Blue shading indicates the control is already partially-implemented at the Site.
White indicates that the control has not been implemented at the Site.
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Support for a Community Institutional Controls Program
A variety of flexible tools are already in place to support the community with institutional controls. A sampling of
the types of tools that could be used to support institutional controls is provided below. The complete list of tools
will be developed in the remedial design process with the intention of providing flexibility to support changing
needs in the community.
Examples of Tools to Support Implementation of Institutional Controls
Tool
Description
History
Future
Fill and topsoil
program
Identification and sampling of approved fill material and
public assistance for access to fill - primarily for
residential/commercial properties.
Soil stockpiled by EPA throughout
removal process. It would support
permit institutional control.
Soil stockpiles
will be
transferred.
Permit
education
Provide information about the requirement for a permit,
the importance of the permit (to protect the remedy and
avoid recontamination), and steps for getting a permit.
Not currently used. It would
support an institutional control for
a local program permit.

Share
information
with realtors
Ensures that all parties involved in a real estate
transaction are aware of any LA contamination.
Not currently used. It would
support a community education
institutional control.
Could be
initiated as part
of education
program.
Land use
change
education
Provides information to property owners about the
requirement to notify of a potential land use change and
how that change could trigger additional cleanup
requirements.
Not currently used. It would
support a local program permit
and the database institutional
controls.

Zonolite Trust
Offer partial reimbursement for removal of attic insulation
contaminated with LA.
www.zonoliteatticinsulation.com
844-924-2255
W.R. Grace initiated in 2014.

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Part Three: Summary of Preferred Alternative
Evaluation
The six remedial alternatives that advanced through the initial screening process were evaluated in detail against
seven of nine evaluation criteria mandated by Superfund law (see below]. The nine criteria fall into three groups:
threshold, primary balancing, and modifying. Each alternative (except no-action] must meet the threshold criteria
to move forward. The primary balancing criteria are then used to weigh major differences in alternatives.
Modifying criteria (state and public acceptance] are generally considered after comments are received on the
proposed plan. EPA has involved the State of Montana in the selection of the preferred alternative as part of the
development of the proposed plan by seeking and incorporating their comments in the proposed plan.
The table below presents the comparative analysis of alternatives against the threshold and balancing criteria. In
general, alternatives that rely primarily on excavation or removal are more expensive and disruptive, but they
offer relatively higher long-term effectiveness and permanence. The feasibility study provides a detailed summary
of the results of the comparison of alternatives.
Do the Remedial Alternatives Meet Superfund Evaluation Criteria?
Alternative Number and Description
Protection
of human
health and
environ-
ment?
Compli-
ance
with
ARARs?
Long-term
effectiveness
and perma-
nence
Treatment*
Short-term
effectiveness
Implement-
ability
Present
value
cost
(dollars)
**
Contaminated Soil Alternatives
SI
No further action
No
No
0
0
0
5
$0.6M
S5
Limited excavation/disposal, covers,
institutional controls and
monitoring
Yes
Yes
3
0
4
4
$35.8M
S6
Partial excavation/disposal, backfill,
institutional controls, and
monitoring
Yes
Yes
4
0
3
3
$53.9M
Contaminated Building Material Alternatives
B1
No further action
No
No
0
0
0
5
$0.3M
B4
Encapsulation, interior cleaning,
institutional controls, and
monitoring
Yes
Yes
2
0
4
3
$9.7M
B5
Partial removal/disposal,
encapsulation, interior cleaning,
institutional controls, and
monitoring
Yes
Yes
4
0
3
3
$9.8M
0 = does not meet criteria/ 5 = best meets criteria	$ to $$$$ = < $1M to $100M
ARARs. Applicable or relevant and appropriate requirements (ARARs table is provided in the feasibility study).
*Reduction of toxicity, mobility, or volume by treatment.
** Present value costs are rounded to nearest $100K. M=million. K=thousand.
EPA's Preferred Alternative
This Site is unusual in that so much removal work has been completed proactively to minimize exposure and risk.
The most significant LA sources were removed before and while the remedial investigation, feasibility study, and
risk assessment were being conducted. With the exception of residential/commercial property, investigations
have generally been completed at the remaining location types and, where necessary, removals have been
completed. If known conditions change, the institutional controls put in place for the location type will address
any necessary testing, cleanup, or other action.
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EPA's preferred alternative for contaminated soil is Alternative S6: Partial excavation/disposal, backfill,
institutional controls, and monitoring. The preferred alternative will address exposures above remedial action
levels through excavation and disposal of soil to a depth of 6 to 36 inches depending on constraints and
concentrations of LA and disposal at the former Libby vermiculite mine. Delineation marker barriers would be
placed over contaminated soil left in place and covered with backfill. Institutional controls and monitoring would
be required.
EPA's preferred alternative for contaminated building materials is Alternative B5: Partial
removal/disposal, encapsulation, interior cleaning, institutional controls, and monitoring. The preferred
alternative will address exposures above remedial action levels through removal and disposal of accessible
contaminated building materials at the Lincoln County landfill. The remaining contaminated building materials
will be encapsulated and interior cleaning will ensure remedial clearance criteria are met for indoor spaces. For
both soil and building materials, the response action must meet the clearance criteria to be considered complete.
Institutional controls and monitoring would be required.
Preferred Alternative by Location Type
Location Type
Contaminated Soil
Alternative S6
Contaminated Building Materials
Alternative B5
Institutional
Controls
Residential/
Commercial
Partially excavate contaminated soil to a
depth of 6 to 36 inches and dispose at the
former Libby vermiculite mine.
Remove accessible contaminated materials and
dispose at Lincoln county landfill, encapsulate
remaining contaminated materials, and clean
interior.
Required
Industrial Park
Transportation
Corridor
Parks and Schools
Work completed and no further action
expected.
Work completed and no further action
expected.
Soil will continue to be disposed of at the former Libby vermiculite mine and building materials will continue to
be disposed of at the Lincoln County landfill. The county landfill has capacity for material through the remainder
of cleanup and during operation and maintenance of the Site.
A robust combination of institutional controls will be used site-wide to ensure the protectiveness of the remedy
over the long-term by managing exposure to remaining contamination. Multiple controls are preferred to ensure
that the remedy remains protective and to ensure that the best tools are used for various scenarios.
EPA's preferred combination of institutional controls is:
¦	UDIG program
¦	Montana Department of Transportation permit
¦	Asbestos support program
¦	Educational program for managing exposure
¦	Property status database
¦	Update codes, ordinances, and regulations
¦	Open space recreation initiative
¦	Public nuisance ordinance
¦	Permit for disturbance of soils or building materials
¦	Contractor certification
¦	Property notices
¦	Advisories
Although the institutional controls need to be technically implementable, EPA and DEQ recognize that these
controls need to be accepted by the community. The community plays an important role in monitoring these
controls. This is why EPA and MDEQ have involved the public in initial planning for institutional controls and why
an additional public meeting is planned for June 30th to evaluate input received on the proposed controls.
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EPA has overall responsibility for developing and implementing institutional controls at the Site while removals
and remedial actions are being conducted. Responsibility shifts to the State of Montana after the remedy is
complete and the Site is in operation and maintenance. EPA would continue to implement enforcement-related
institutional controls because they apply to legal agreements between EPA and potentially responsible parties.
EPA would also review the effectiveness of institutional controls along with the engineered components of the
remedy during post-construction five-year site reviews.
Institutional controls are required to be maintained over time, so monitoring and reporting will be needed to
ensure that the controls remain in place, are functioning as intended, and that the remedy remains protective.
Monitoring and reporting will be conducted according to a schedule established by the Institutional Control and
Implementation and Assurance Plan, which will be prepared following development of the record of decision. EPA
and DEQ will also continue to involve the public throughout the design process.
What Would Trigger a Cleanup?
Remedial Action Levels by Location Type
Contaminated Soil
Contaminated Building Material
Residential and Commercial:
Frequently Used Areas
•	LA soil concentrations greater than 0.2% (anywhere in total soil exposure area)
OR
•	More than 25% of total soil exposure area has LA at trace concentrations
(detectable but less than or equal to 0.2%)
Infrequently Used Areas
•	LA soil concentrations greater than 0.2%
All location types:
•	Accessible LA-containing vermiculite in any
quantity in living spaces, non-living spaces and
/or secondary structures
OR
•	Accessible building materials with more than
0.25% LA (examples include chinking, plaster,
mortar and other materials on boilers and
pipes)
Industrial and Transportation:
• LA soil concentrations equal to or exceeding 1%
Schools and Parks
• LA soil concentrations greater than 0.2%
Remedial action levels initiate cleanups to reduce LA exposures so that resulting risks will achieve the remedial
action objectives. To meet these objectives, EPA will perform cleanup until the remedial clearance criteria are met.
Since the remedial clearance criteria may leave LA contamination in subsurface soils or within inaccessible areas
of buildings, institutional controls will be implemented to address LA contamination that remains after the
physical cleanup is complete. These institutional controls will also protect the integrity of the physical cleanup
components, thereby achieving the remediation goals.
Remedial Clearance Criteria
Contaminated Soil
Contaminated Building Material
Surface Soil (After
Subsurface Soil (After Cleanup)
Indoor Non-living Space
Indoor Living Space
Cleanup)
Residential, Commercial, Schools
• No accessible vermiculite
• No accessible vermiculite
• LA soil concentrations
and Parks:
remaining
remaining
are below remedial
• LA soil concentrations for samples
• Average of five samples of
• No LA structures detected in
action levels for the
collected at the depth of cut are
disturbed air are less than
any of five samples of
location type
less than 0.2%
0.005 structures per cubic
disturbed air

Industrial and Transportation:
centimeter




• LA soil concentrations for samples



collected at the depth of cut are



less than 1%


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How Does the Preferred Alternative Meet Evaluation Criteria?
Details about the preferred alternative and how it meets these criteria are provided in the feasibility study and
summarized below:
Protection of human health and the environment: It mitigates exposure pathways for inhalation of LA from
contaminated soil and building materials by removing the majority of those materials from the property and
managing the remainder.
Compliance with ARARs: It meets ARARs for air by addressing sources and preventing discharges. Location-
specific and action-specific ARARs are also addressed through consideration of requirements during design of the
remedy and proper work practices for handling of soil and building materials, backfill, revegetation, and dust
suppression during construction.
Long-term effectiveness and permanence: It meets this requirement better than other alternatives by
removing the majority of contamination from the property and managing the remainder using institutional
controls and monitoring. Long-term effectiveness and permanence is more certain than for alternatives that rely
primarily on containment.
Reduction of toxicity, mobility, or volume by treatment: The proposed alternative does not include treatment,
however the preferred alternative will reduce mobility of LA.
Short-term effectiveness: Short-term risks to the community, workers and the environment are higher than
with other alternatives due to increased disturbances created by excavation and increased truck traffic for hauling
of contaminated soil/materials and clean fill. However, these risks can be mitigated with safety measures
(personal protective equipment, dust suppression and work zones],
Implementability: It uses more construction equipment for longer periods than other alternatives, which makes
implementation and coordination more difficult. Longer construction periods mean longer temporary relocations
of residents and businesses. Fill sources must be developed and excavation of contaminated soil and placement of
fill may be challenging in some areas. Work zones and protective measures must be established. Future
inspection, monitoring, and maintenance and implementation of institutional controls will pose challenges but is
lessened by greater removal of contaminated soil and building materials than relying on containment.
Cost: It is the most expensive alternative of those retained for analysis; however, it provides the best long-term
effectiveness and permanence. The presentvalue cost for soil is approximately $53.9M and for contaminated
building materials is approximately $9.8M.
State Acceptance: As stated in an April 2, 2015 letter to EPA, "DEQ generally agrees with the preferred
alternative as described in the proposed plan, with the concerns and reservations outlined and summarized (in
the letter], DEQ agrees with the proposed remedial action levels for residential and commercial soils, parks and
schools soils, and interiors. DEQ also supports the clearance criteria for all soils. Together the remedial action
levels and clearance criteria are the 'remediation goals,' as required under the NCP. DEQ appreciates that EPA is
planning to have an extended 'last-call' program, so as to ensure that all of the properties are cleaned up and all
of the institutional controls are in place and effective; DEQ continues to ask that this 'last-call' program last ten
years."
Public Acceptance: Community acceptance of the proposed plan will be evaluated after the public comment
period ends and will be described in the record of decision.
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Conclusion
EPA's preferred alternative is similar to EPA's removal program which has successfully reduced exposures to LA.
The institutional controls would ensure that LA encountered in the future is properly managed. EPA's preferred
alternative best meets the evaluation criteria.
The State of Montana accepts the preferred alternative as described in this proposed plan. EPA recognizes that
DEQ has additional comments that will be addressed in the record of decision and subsequent design documents.
DEQ's comments include implementation of binding and enforceable institutional controls, state authority to
address interior cleanups and expectations of the property owner, evaluation of all previous removal actions to
ensure there is no unacceptable risk left behind, monitoring of waste remaining in place, transportation corridor
action level, no further action status of 0U6, and remediation depth in utility corridors. EPA agrees with DEQ that
there is a need for a robust "last call" for cleanup. At this time EPA anticipates a last call for a few years depending
on residential participation and consent to access.
With this document, EPA is soliciting public comments on its preferred remedy. EPA encourages the public to
review and comment on the cleanup options evaluated in this proposed plan and other documents in the
Administrative Record during the public comment period. The public comment period is May 8, 2015 to July 8,
2015. EPA and DEQ will host public meetings during the comment period to present the proposed plan and
supporting information, answer questions, and accept both oral and written comments from the public. Please see
page one of this document for details about the public meetings.
Site Documents
Community members can access the Information Repository and Administrative Record containing all documents that
support this proposed plan at the following locations:
Lincoln County Library in Libby, 220 West 6th Street. Hours: Tuesday - Saturday 10 a.m. to 6 p.m.
Lincoln County Library in Troy, 207 3rd Street. Hours: Tuesday- Friday 11 a.m. to 5 p.m., Sat. 11 a.m. to 2 p.m.
EPA Superfund Records Center, 1595 Wynkoop Street, Denver, CO 80202, (303) 312-6473. Call for appointment.
If you have questions about the site or would like more information, please contact the EPA Information Center, 108 E.
9th Street, Libby, Montana 59923, (406) 293-6194.
We Want Your Input
Your input is important to EPA and the State of Montana. Public comment helps us select a final cleanup decision. EPA
is accepting comments between May 8 and July 8, 2015 on this proposed plan and all supporting documents in the
Administrative Record, including the remedial investigation, feasibility study and draft human health risk assessment.
Three ways to submit written comment:
1)	Place comments in a comment box at the public meetings.
2)	Bring comments to EPA's Libby Information Center, 108 E. 9th Street, Libby, Montana 59923
3)	Email comments to EPALibbyPlan@epa.gov or mail to:
Rebecca Thomas
Project Manager
U.S. EPA Region 8 (EPR-SR)
1595 Wynkoop Street
Denver, Colorado 80202
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Site Contacts for the Libby Asbestos Superfund Site
Organization
Name
Mailing Address
Phone
Email
U.S.
Environmental
Protection
Agency
Rebecca Thomas, Project Manager
U.S. EPA, Region 8
1595 Wynkoop Street
Denver, Colorado 80202
800-227-8917,
X312-6552
thomas.rebecca@epa.gov
Jennifer Lane, Community
Involvement Coordinator
800-227-8917,
X312-6813
lane.jennifer@epa.gov
EPA Superfund Records Center
303-312-6473
—
Mike Cirian, On-Site Project
Manager, EPA Information Center
108 E. 9th Street
Libby, Montana 59923
406-293-6194
cirian.mike@epa.gov
EPA website
www2.epa.gov/region8/libby-asbestos
Montana
Department of
Environmental
Quality
Jeni Flatow, Public Information
Officer
Montana DEQ
P.O. Box 200901,
Helena, Montana 59601
www.deq.mt.gov
406-444-6422
jflatow@mt.gov
Lisa DeWitt, Project Officer
406-444-6420
lidewitt@mt.gov
Lincoln County
Asbestos Resource Program
418 Mineral Ave
Libby, Montana 59923
www.lcarp.org
406-291-5335
lcarp@libby.org
Technical
Advisory Group
Mike Noble

406-293-3539 or
406-293-0611
(cell)
mcnoblell51@gmail.com
Community
Advisory Group
Mike Giesey

406-283-7630
mgiesey_card@hotmail.com
Public Meetings for the Proposed Plan
EPA is hosting two public meetings to present the proposed plan. Please join us!
Wednesday, May 20, 7 to 9 p.m.
Kootenai Senior Center, 304 3rd St., Troy
Thursday, May 21, 7 to 9 p.m.
City of Libby's Ponderosa Room
952 E. Spruce St., Libby
Public comment period is May 8 to July 8, 2015.
EPA is taking comment on this proposed plan and all supporting documents in the Administrative Record,
including the remedial investigation, feasibility study and draft human health risk assessment during this
period.
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