National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List: Partial Deletion of the Idaho Pole Company Superfund Site, 34839-34845 [2019-15305]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 84, Number 139 (Friday, July 19, 2019)]
[Proposed Rules]
[Pages 34839-34845]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-15305]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 300

[EPA-HQ-SFUND-1986-0005; FRL-9996-90-Region 8]


National Oil and Hazardous Substances Pollution Contingency Plan; 
National Priorities List: Partial Deletion of the Idaho Pole Company 
Superfund Site

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule; notice of intent.

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SUMMARY: The Environmental Protection Agency (EPA) Region 8 is issuing 
a Notice of Intent to Delete the surface and unsaturated subsurface 
soils outside of the 4.5 acre Treated Soils Area of the Idaho Pole 
Company Superfund Site (Site) located in Bozeman, Gallatin County, 
Montana, from the NPL, promulgated pursuant to section 105 of the 
Comprehensive Environmental Response, Compensation, and Liability Act 
(CERCLA) of 1980, as amended, is an appendix of the National Oil and 
Hazardous Substances Pollution Contingency Plan (NCP). The EPA and the 
State of Montana, through the Montana Department of Environmental 
Quality (MDEQ), have determined that all appropriate response actions 
at these identified media under CERCLA, other than operation and 
maintenance, monitoring and five-year reviews have been completed. 
However, this deletion does not preclude future actions under 
Superfund.
    This partial deletion pertains to the surface and unsaturated 
subsurface soils remedy component outside of the 4.5 acre Treated Soils 
Area of the Idaho Pole Company Superfund Site. The 4.5 acre Treated 
Soils Area is identified on the survey map in the docket and is the 
location where all treated soils were placed after on-site treatment. 
The groundwater and saturated subsurface soils within the historic 
groundwater table, and the Site's sediments are not being considered 
for deletion as part of this action.

DATES: Comments must be received by August 19, 2019.

ADDRESSES: Submit your comments, identified by Docket ID no. EPA-HQ-
SFUND-1986-0005, by one of the following methods:
     https://www.regulations.gov. Follow on-line instructions 
for submitting comments. Once submitted, comments cannot be edited or 
removed from Regulations.gov. The EPA may publish any comment received 
to its public docket. Do not submit electronically any information you 
consider to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Multimedia 
submissions (audio, video, etc.) must be accompanied by a written 
comment. The written comment is considered the official comment and 
should include discussion of all points you wish to make. The EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e. on the web, cloud, or other file sharing 
system). For additional submission methods, the full EPA public comment 
policy, information about CBI or multimedia submissions, and general 
guidance on making effective comments, please visit https://www.epa2.gov/dockets/commenting-epa-dockets.
     Email: [email protected].
     Mail: Roger Hoogerheide, Remedial Project Manager; U.S. 
EPA Montana Office; Federal Building, Suite 3200; 10 West 15th Street; 
Helena, MT 59626.
     Hand delivery: U.S. EPA Montana Office; Federal Building, 
Suite 3200; 10 West 15th Street; Helena, MT 59626. Such deliveries are 
only accepted during the Docket's normal hours of operation, and 
special arrangements should be made for deliveries of boxed information 
by calling 406-457-5046.
    Instructions: Direct your comments to Docket ID no. EPA-HQ-SFUND-
1986-0005. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at https://www.regulations.gov, including any personal 
information provided, unless the comment includes information

[[Page 34840]]

claimed to be Confidential Business Information (CBI) or other 
information whose disclosure is restricted by statute. Do not submit 
information that you consider to be CBI or otherwise protected through 
https://www.regulations.gov or email. The https://www.regulations.gov 
website is an ``anonymous access'' system, which means the EPA will not 
know your identity or contact information unless you provide it in the 
body of your comment. If you send an email comment directly to the EPA 
without going through https://www.regulations.gov, your email address 
will be automatically captured and included as part of the comment that 
is placed in the public docket and made available on the internet. If 
you submit an electronic comment, the EPA recommends that you include 
your name and other contact information in the body of your comment and 
with any disk or CD-ROM you submit. If the EPA cannot read your comment 
due to technical difficulties and cannot contact you for clarification, 
the EPA may not be able to consider your comment. Electronic files 
should avoid the use of special characters, any form of encryption, and 
be free of any defects or viruses.
    Docket: All documents in the docket are listed in the https://www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in the hard 
copy. Publicly available docket materials are available either 
electronically in https://www.regulations.gov or are available 
electronically or in hard copy at: U.S. EPA Montana Office, Federal 
Building, Suite 3200, 10 West 15th Street, Helena, MT 59626, (406) 457-
5046, Hours: Mon.-Fri. 8 a.m. to 5 p.m.; and the Bozeman Public 
Library, 626 East Main Street, Bozeman, MT 59715, (406) 582-2400, 
Hours: (Library hours vary).

FOR FURTHER INFORMATION CONTACT: Roger Hoogerheide, Remedial Project 
Manager, 8SEM-RBS, U.S. EPA, Region 8--Montana Office, 10 W 15th St., 
Suite 3200, Helena, Montana 59626, (406) 457-5031 or 1-866-457-2690, 
extension 5031, [email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Introduction
II. NPL Deletion Criteria
III. Deletion Procedures
IV. Basis for Intended Partial Site Deletion

I. Introduction

    The EPA announces its intent to delete the surface and unsaturated 
subsurface soils of the Idaho Pole Company Superfund Site (Site) 
outside of the 4.5 acre Treated Soils Area, from the National 
Priorities List (NPL) and request public comment on this proposed 
action. The NPL constitutes Appendix B of 40 CFR part 300 which is the 
National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 
which the EPA promulgated pursuant to section 105 of the Comprehensive 
Environmental Response, Compensation and Liability Act (CERCLA) of 
1980, as amended. The EPA maintains the NPL as those sites that appear 
to present a significant risk to public health, welfare, or the 
environment. Sites on the NPL may be the subject of remedial actions 
financed by the Hazardous Substance Superfund (Fund). The EPA proposed 
the facility for listing on the NPL in 1984, 29 FR 40320 (Oct. 15, 
1984). The listing was final in 1986, 51 FR 21054 (June 10, 1986).
    This partial deletion of the surface and unsaturated subsurface 
soils totaling approximately 82 acres at the Idaho Pole Company 
Superfund Site is proposed in accordance with 40 CFR 300.425(e) and is 
consistent with the Notice of Policy Change: Partial Deletion of Sites 
Listed on the National Priorities List. 60 FR 55466 (Nov. 1, 1995). As 
described in 300.425(e)(3) of the NCP, a portion of a site deleted from 
the NPL remains eligible for Fund-financed remedial action if future 
conditions warrant such actions. Any remaining contaminated saturated 
soils, sediments and groundwater at the Idaho Pole Company Superfund 
site as well as the 4.5 acres within the Treated Soils Area will remain 
on the NPL and are not subject to this partial deletion action.
    The EPA will accept comments on the proposal to partially delete 
this site for thirty (30) days after publication of this document in 
the Federal Register.
    Section II of this document explains the criteria for deleting 
sites from the NPL. Section III discusses procedures that the EPA is 
using for this action. Section IV discusses the response actions that 
have addressed the surface and unsaturated subsurface soils of the 
Idaho Pole Company Superfund Site and demonstrates how it meets the 
deletion criteria.

II. NPL Deletion Criteria

    The NCP establishes the criteria that the EPA uses to delete sites 
from the NPL. In accordance with 40 CFR 300.425(e), sites may be 
deleted from the NPL where no further response is appropriate. In 
making such a determination pursuant to 40 CFR 300.425(e), the EPA will 
consider, in consultation with the State, whether any of the following 
criteria have been met:
    i. Responsible parties or other persons have implemented all 
appropriate response actions required;
    ii. All appropriate Fund-financed response under CERCLA has been 
implemented, and no further response action by responsible parties is 
appropriate; or
    iii. The remedial investigation has shown that the release poses no 
significant threat to public health or the environment and, therefore, 
the taking of remedial measures is not appropriate.
    Pursuant to CERCLA section 121(c) and the NCP, the EPA conducts 
five-year reviews to ensure the continued protectiveness of remedial 
actions where hazardous substances, pollutants, or contaminants remain 
at a site above levels that allow for unlimited use and unrestricted 
exposure. The EPA conducts such five-year reviews even if a site is 
deleted from the NPL. The EPA may initiate further action to ensure 
continued protectiveness at a deleted site if new information becomes 
available that indicates it is appropriate. Whenever there is a 
significant release from a site deleted from the NPL, the deleted site 
may be restored to the NPL without application of the hazard ranking 
system.

III. Deletion Procedures

    The following procedures apply to deletion of the surface and 
unsaturated subsurface soils of the Site:
    (1) The EPA consulted with the State before developing this Notice 
of Intent for Partial Deletion.
    (2) The EPA has provided the state 30 working days for review of 
this notice prior to publication of it today.
    (3) In accordance with the criteria discussed above, the EPA has 
determined that no further response is appropriate.
    (4) The State of Montana, through the MDEQ, has concurred with the 
deletion of the surface and unsaturated subsurface soils of the Idaho 
Pole Company Superfund Site, from the NPL.
    (5) Concurrently, with the publication of this Notice of Intent for 
Partial Deletion in the Federal Register, a notice is being published 
in The Bozeman Daily Chronicle. The newspaper notice announces the 30-
day public comment period concerning the Notice of Intent for Partial 
Deletion of the Site from the NPL.

[[Page 34841]]

    (6) The EPA placed copies of documents supporting the proposed 
partial deletion in the deletion docket, made these items available for 
public inspection, and copying at the Site information repositories 
identified above.
    If comments are received within the 30-day comment period on this 
document, the EPA will evaluate and respond accordingly to the comments 
before making a final decision to delete the surface and unsaturated 
subsurface soils outside of the 4.5 acre Treated Soils Area. If 
necessary, the EPA will prepare a Responsiveness Summary to address any 
significant public comments received. After the public comment period, 
if the EPA determines it is still appropriate to delete the surface and 
unsaturated subsurface soils of the Idaho Pole Company Superfund Site 
outside of the 4.5 acre Treated Soils Area, the Regional Administrator 
will publish a final Notice of Partial Deletion in the Federal 
Register. Public notices, public submissions and copies of the 
Responsiveness Summary, if prepared, will be made available to 
interested parties and included in the Site information repositories 
listed above.
    Deletion of a portion of a site from the NPL does not itself 
create, alter, or revoke any individual's rights or obligations. 
Deletion of a portion of a site from the NPL does not in any way alter 
the EPA's right to take enforcement actions, as appropriate. The NPL is 
designed primarily for informational purposes and to assist EPA 
management. Section 300.425(e)(3) of the NCP states that the deletion 
of a site from the NPL does not preclude eligibility for future 
response actions, should future conditions warrant such actions.

IV. Basis for Intended Partial Site Deletion

    The following information provides the EPA's rationale for deleting 
the surface and unsaturated subsurface soils outside of the 4.5 acre 
Treated Soils Area of the Idaho Pole Company Superfund Site from the 
NPL.

Site Background and History

    The Idaho Pole Company Superfund Site, CERCLIS ID MTD00623276, is 
located near the northern limits of Bozeman, Gallatin County, Montana. 
The Site occupies approximately 87 acres in the east half of Section 6 
and the west half of Section 5, Township 2S, Range 6E of Gallatin 
County. The Site is bounded by the Montana Rail Link (MRL) railroad 
tracks to the south, L Street to the west and Rocky Creek to the east 
and north of the Site. Interstate Highway 90 (I-90), Bohart Lane and 
Cedar Street traverse the Site in an east-west direction.
    The four parcels south of I-90, north of the MRL railroad tracks 
and east of L Street are part of this partial deletion. The four 
parcels are owned by the Idaho Pole Company (IPC) and total 
approximately 40 acres. These parcels contain the groundwater recovery 
system building and associated extraction and injection galleries, a 
log cabin structure that was historically used by the site manager but 
is currently unoccupied, and an office building. The remaining area is 
an open field. The four parcels are within Bozeman's city limits and 
are currently zoned for commercial/industrial use. Cedar Street 
transects this section of the Site. A portion of two of these parcels 
contains the 4.5 acre Treated Soils Area. This is where treated soils 
that do not allow for unlimited use and unrestricted exposure have been 
placed and a Notice of Institutional Controls has been filed on the 
deed with Gallatin County Clerk and Recorder restricting excavation and 
construction in this area without specific approval from the State of 
Montana and the EPA.
    The Idaho Pole Company also owns the parcel immediately north of 
Bohart Lane and east of L Street which is part of this partial 
deletion. This parcel is currently fenced to restrict access since 
there was an interceptor trench that was used to historically recover 
wood treating fluids. Product that accumulated in the trench was 
removed from the trench using absorbent pads, as needed. Operation of 
the trench ceased in October 2015 after several years where no product 
was recovered, and the trench was closed per the EPA approved Trench 
Closure Work Plan. The fence is not needed for the remedy and can be 
taken down to facilitate redevelopment of the property. There are no 
structures on this property. This approximately seven-acre parcel is 
identified as the Pasture Area in site documents and is within Bozeman 
city limits. The property is zoned for commercial/industrial use and 
there is a potential to place commercial structures on this property in 
the future.
    Approximately eighteen additional acres on three parcels owned by 
IPC north of Bohart Lane, south of Rocky Creek and east and west of L 
Street are also part of this partial deletion. There are currently no 
structures on these properties and these parcels are occasionally used 
by nearby residents as pasture. These parcels are outside of Bozeman 
city limits in unincorporated Gallatin County and are zoned rural 
residential.
    In addition to property owned by IPC, approximately seven acres is 
owned by Northwestern Energy (formerly Montana Power Company) including 
the East Gallatin Substation. This parcel is immediately north of 
Bohart Lane and east of the Pasture Area parcel. The East Gallatin 
Substation was constructed in the mid-1970's and serves the northeast 
side of Bozeman.
    Another approximately fifteen acres includes the portions of I-90, 
Cedar Street, and Bohart Lane that transect the Site as well as the 
right away associated with these roads. Privately-owned land north and 
east of Rocky Creek and west of L Street are only included in the 
groundwater portion of the Site and are not part of this partial 
deletion. Interstate Highway 90 was constructed through the property 
north of the facility from 1967 to 1969. Historically, the land now 
occupied by 1-90 and the area northeast of 1-90 to Rocky Creek was 
predominantly used for residential and ranch purposes.
    Between the late 1800s and early 1940s, the Northern Pacific 
Railroad Company operated a five-stall roundhouse south of Cedar Street 
and east of L Street that was used for light maintenance and to house 
helper engines that were used to pull and push trains up and down 
Bozeman Pass. Modifications to the roundhouse were periodically 
completed to accommodate larger helper engines that came into service. 
The roundhouse was considered obsolete with the development of diesel 
engines in the 1930s that had sufficient power to traverse Bozeman Pass 
without helper engines and the roundhouse was abandoned in the early 
1940s.
    The IPC wood treating facility began operations in 1945 using 
creosote to preserve wood. The creosote was mixed with a petroleum 
distillate and heated in vats prior to treatment. Creosote contains 
several larger hydrocarbon molecules (polynuclear aromatic hydrocarbons 
(PAHs)) which are identified as contaminants of concern at the Site.
    Lodgepole pine and cedar (white wood) poles were brought to the 
Site by rail and truck and stored until treated. White wood was stored 
near the former roundhouse area as well as between the treatment 
facilities and the MRL railroad tracks awaiting treatment. The wood 
treatment process was initiated via a customer order. Prior to 
treatment, the bark was removed from the poles and excess bark was 
stored in piles on-site at the east side of the property on both the 
north and south sides of Cedar Street.

[[Page 34842]]

    In the early days of Site operations, treatment consisted of 
immersion of the end of the poles into a butt vat of heated creosote 
solution. This was later extended to full length pole treatment with 
the installation of a full-length vat in 1952. There was also a drying 
area on-site where treated poles were stored temporarily prior to 
shipment off-site. Since most orders were custom orders, treated poles 
only stayed on-site for a few days before transport to the customer.
    In 1952, IPC switched to pentachlorophenol (PCP) for wood 
treatment. Initially, any remaining creosote was cycled in with PCP 
rather than disposed on-site since there were few customer concerns 
about the color of the treated wood. Pentachlorophenol continued to be 
used until wood treatment operations ceased in 1997. Pentachlorophenol 
is a known carcinogen and is also identified as a contaminant of 
concern at the Site.
    The PCP was brought to the Site in bulk as a solid and was diluted 
as a 5% solution in a carrier oil and heated in vats prior to wood 
treatment. Commercial grade PCP usually contains about 86% PCP purity 
and 14% other impurities such as chlorophenols and dioxins/furans. The 
other chlorophenols include compounds such as tetrachlorophenol, 
trichlorophenol, and dichlorophenol. Dioxins/furans produced during the 
manufacturing of PCP are the result of improper combustion.
    In 1975, a pressurized heated retort was added for treating full 
length poles and placed in the Pressure Plant. The full-length vat used 
to treat full-length poles that was installed in 1952 was taken out of 
service in 1979 and demolished in 1981. Wood treating operations 
continued with the pressurized heated retort and the butt vat until 
1997 when wood-treating operations ceased.
    The full-length vat that was decommissioned in 1979 had corroded on 
the bottom and the vat leaked an unknown amount of wood treating fluid 
into the underlying soil and groundwater for an undetermined amount of 
time resulting in the majority of releases observed at the Site. System 
operations also resulted in the occasional spilling of heated wood 
treating fluids on nearby soils around treatment facilities. All 
treatment operations described above occurred around the 4.5 acre 
Treated Soils Area located south of I-90.
    In 1978, the Montana Department of Fish, Wildlife and Parks 
notified the Montana Department of Health & Environment (MDHES) of a 
suspected release of oily wood treating fluid from the plant. MDHES 
found evidence of a release in ditches near the facility and near Rocky 
Creek. Consequently, MDHES issued a compliance order on September 29, 
1978, notifying IPC of statutory violations and directing the company 
to stop uncontrolled releases and to clean up spilled treating fluid. 
Between 1978 and 1980, IPC installed an interceptor trench and drain 
that ran parallel to I-90 to collect non-aqueous phase liquid (NAPL) on 
the groundwater surface. In 1984, IPC hired a consultant to investigate 
soil, sediment, surface water, and groundwater contamination. The 
results of the investigation, which was conducted without MDHES or EPA 
oversight, are presented in a 1985 report. The EPA proposed the 
facility for listing on the NPL in 1984, 29 FR 40320 (Oct. 15, 1984). 
The listing was final in 1986, 51 FR 21054 (June 10, 1986).

Remedial Investigation and Feasibility Study (RI/FS)

    In March 1989, MDHES requested and received the lead agency role 
for a fund-financed RI/FS for the Site. The RI defined the nature and 
extent of contamination and provided data to complete the baseline 
Human Health and Ecological Risk Assessments. Contaminated surface 
soils were identified around the treatment facilities, north and south 
of Cedar Street, near the former roundhouse and in the Pasture Area. 
Contamination of the groundwater saturated subsurface soils occurred 
within the bounds of the 6.7-acre wood treating NAPL contamination area 
identified in Figure 5-3 of the RI Report. This subsurface NAPL 
resulted in the smearing of oily wood treating fluid in the subsurface 
during the seasonally fluctuating groundwater table. At high water 
table conditions, the oily wood treating fluid expressed near the 
ground surface in the Pasture Area north of I-90, resulting in isolated 
pockets of wood treating fluid in the subsurface soils.
    Upon completion of the RI Report, the Feasibility Study (FS) 
commenced. The primary objective of the FS was to provide sufficient 
information to support an informed risk management decision to select 
the most appropriate cleanup remedy for the IPC Site. The soil 
component of the remedy identified excavation and on-site treatment of 
accessible soils as the most appropriate remedy. Inaccessible soils 
(saturated subsurface soils, soils under I-90 and active facility 
operations) would be addressed as part of the groundwater remedy.
    For human health protection, the remedial action objectives 
identified in the FS for soil are to:
     Prevent excess incidence of cancer risks from exceeding 1 
in 10,000 following lifetime direct contact with, and ingestion of, 
soils contaminated with carcinogenic contaminants of concern (CoCs);
     Prevent ingestion of/direct contact with soils having 
noncarcinogens at levels which exceed the reference doses; and
     Prevent excess incidence of cancer risks from exceeding 1 
in 10,000 following inhalation of carcinogenic CoCs at a lifetime of 
exposure.
    For environmental protection, the remedial action objective for 
soil is to:
     Prevent migration of contaminated leachate that would 
result in groundwater contamination in excess of the proposed maximum 
contaminant levels (MCLs). (Proposed MCLs are To Be Considered as 
Applicable Relevant and Appropriate Requirements).

Selected Remedy

    Following issuance of a Proposed Plan, the EPA released a Record of 
Decision (ROD) in 1992. A remedial alternative for soil and groundwater 
that is protective of human health and the environment was selected. 
The COCs identified in the ROD are PCP, PAHs, polychlorinated dibenzo-
p-dioxins and polychlorinated dibenzofurans (dioxins/furans) which are 
reported as a toxicity equivalent value of 2,3,7,8-tetrachlorodibenzo-
p-dioxin (TCDD TEQ)). One Operable Unit (OU01) was established for the 
Site and included the soil and groundwater component. The EPA's remedy 
selection was based on the assumption that IPC would continue its 
commercial operations, limiting access to soils underlying operating 
structures.
    The major components of the selected remedy that addressed 
contaminated surface and unsaturated subsurface soils include:
     Excavation and surface land biological treatment on-site 
of accessible contaminated soils from the Pasture Area and the area 
between Cedar Street and I-90 including ditch sediments or bottoms, and 
the former roundhouse area;
     Hot water and steam flushing of inaccessible soils 
underlying the active pole plant facility and I-90 in order to recover 
hazardous substances;
     Separation and disposal of oily wood treating fluid 
extracted from soils; and
     Implement land use and deed restrictions (Institutional 
Controls) to preserve the integrity of the remedy.

[[Page 34843]]

    The ROD established performance standards deemed protective of 
human health and the environment for both soils and groundwater. Site 
specific soil performance standards of known or suspected carcinogenic 
contaminants (PCP, TCDDs, and Total class B2 PAHs) were developed based 
on a cancer risk of 1.0 x 10-6. Noncancer contaminant (Total 
class D PAHs) soil performance standards were developed based on a 
noncancer health hazard quotient of 0.1. Soil performance standards 
also assumed future commercial/industrial use for the properties south 
and immediately north of I-90. The soil performance standards 
established in the ROD are:
     PCP <48 milligrams/kilogram (mg/kg)
     Total class B2 PAHs (carcinogen or suspected carcinogen) 
<15 mg/kg
     Total class D PAHs (non-carcinogen) <145 mg/kg
     TCDD TEQ (dioxin toxicity equivalent) <1.0 x 
10-3 mg/kg (1.0 [micro]g/kg)
    The NAPL contaminated area was also revised in the ROD to cover 7.4 
acres and assumed 39,304 cubic yards of contaminated soil exceeded soil 
performance standards. The ROD also assumed that the soil component and 
the groundwater component of the selected remedy would operate 
simultaneously to eliminate the PAHs, PCP and TCDDs that may continue 
to migrate downward from the unsaturated soils to the saturated 
subsurface soils and groundwater, and to remove as much of the 
contamination that is already present in the saturated subsurface soils 
and groundwater to the extent practicable.
    The EPA initiated negotiations with the potentially responsible 
parties (PRPs) for implementation of the remedy after issuance of the 
ROD. The PRPs identified were the Idaho Pole Company and Burlington 
Northern Santa Fe Railway Company (BNSF), as successor to the Northern 
Pacific Railway Company. The negotiations were unsuccessful and 
consequently the EPA issued a Unilateral Administrative Order for 
Remedial Design/Remedial Action (EPA Docket No. CERCLA VIII-93-26) with 
an effective date of August 26, 1993. Remedial Design commenced on 
February 23, 1994 with EPA approval of the Remedial Design Work Plan.
    The findings of additional studies conducted during the Remedial 
Design included modifications to the soil remedy design which were not 
included in the 1992 ROD. These modifications were made through an 
Explanation of Significant Difference (ESD) in 1996 and are listed 
below.
     Based on the subsurface conditions under I-90 and the 
Pressure Plant, the EPA and MDEQ, formerly MDHES, determined that the 
hot water/steam flushing system called for in the ROD could not be 
implemented. These subsurface conditions included the Site geology, 
obstructions under the Pressure Plant foundation, and less oily wood-
treating fluid than originally anticipated in the ROD. The EPA and MDEQ 
approved an alternative plan that increased the area within which soils 
were excavated by adding the accessible plant area soils and Cedar 
Street soils that exceeded the PCP performance standard of 48 mg/kg for 
soils. Soil flushing with ambient temperature water mixed with 
nutrients underneath the plant structures and I-90 would be designed as 
part of the groundwater remedy.
     Closer evaluation of the existing and additional data 
collected post-ROD indicated that the ROD cleanup levels were not 
exceeded in the East Gallatin Substation ditch. Therefore, no ditch 
sediments needed to be excavated.
     A Land Treatment Unit (LTU) was to be constructed in the 
southeast corner of the pole storage yard and the excavated soil from 
all targeted areas of the Site were to be screened to remove rocks and 
placed directly on the LTU. The total soil depth on the LTU was to be 
less than two feet. The LTU would operate to treat the soils to 
approximately one foot in depth and the soils would be removed when ROD 
performance standards were met.
     The treated soils may be used for fill material on 
excavated areas of the Site. If the soil contains other contaminants 
(e.g., dioxins/furans) that exceed the ROD performance standards after 
treatment, the treated soil will be isolated from groundwater; will be 
covered with a minimum of twelve inches at the surface to prevent 
direct contact and Institutional Controls on future land use will be 
required. A detailed closure plan for the LTU will be developed when 
soil monitoring results indicate that the cleanup levels for PCP and 
PAHs have been achieved. The closure plan will identify the areas to be 
backfilled with the treated soil and will specify separation from 
groundwater and the depth of cover required. The plan will also 
identify the specific Institutional Controls to be implemented on the 
Site.
    In the fall of 1997, IPC announced that it would terminate wood 
treatment operations. This had the potential to change the scope of the 
remedial action which required another ESD. The significant difference 
between the remedy described in the 1992 ROD and in the 1998 ESD was 
that the existing plant structures, including concrete pads, piping, 
vaults, etc., preventing access to contaminated soil, were to be 
demolished and disposed of in accordance with State of Montana and EPA 
requirements. Contaminated soils underlying these areas were to be 
excavated and treated in the LTU like the accessible soils elsewhere at 
the facility had been treated to date.

Response Actions

    The soil remedy identified in EPA's ROD and supplemented in the 
subsequent ESDs was implemented between July 1995 and October 2002. The 
remedy included construction of a lined LTU and a retention pond to 
collect any runoff from the LTU; excavation of soils in the accessible 
areas of the Site, as well as de-rocking and transportation of 
excavated soils to the LTU. The LTU was constructed per EPA approved 
plans and specifications. The soils were treated in the LTU until ROD 
performance standards for PCPs and PAHs were met at which time they 
were placed in the excavated areas on-site above historic high 
groundwater levels and clean soil placed on top. The ROD contemplated 
pre-treatment of the excavated soils to remove NAPL prior to placement 
in the LTU. However, this step was determined to not be necessary 
because there was insufficient NAPL in the excavated soil to remove.
    Approximately 14,000 cubic yards of contaminated soil were placed 
in the LTU in 1995. The soils were excavated from six areas at the 
Site: The Pressure Plant Area, beneath Cedar Street, the Barkfill Area, 
the Roundhouse Area, the Cedar Street Ditch and the Pasture Area. The 
majority of soils in the Barkfill and Pasture Areas were contaminated 
by NAPL smearing of the saturated subsurface soils. Clean overburden 
above the saturated soils was stripped off in these locations and 
stockpiled for use as backfill. The exposed NAPL impacted silty clay 
layer located just below and above the water table was then excavated 
and placed in the LTU. Excavated soils were treated in the LTU by 
tilling, irrigation and nutrient addition with a retention pond 
collecting any excess water, which was subsequently treated in the 
groundwater recovery system. Prior to placement of contaminated soils 
into the LTU, the excavated soils were de-rocked, the rock cleaned and 
stockpiled for later use. The clean overburden acquired during the 
excavation of the Barkfill and Pasture Areas was used as fill in the 
Pasture Area, the Roundhouse, Cedar Street and

[[Page 34844]]

Cedar Street ditch excavations so that there were no open excavated 
areas filled with groundwater during soil treatment in the LTU except 
near the facilities.
    The first phase of soils excavated in 1995 were treated in two 10-
inch-thick lifts. The first lift included approximately 4,900 cubic 
yards which met ROD performance standards for PCP and PAH by 1998. A 
workplan to remove the upper lift from the LTU was approved by the EPA 
on March 2, 1999. Removal and placement of these treated soils in the 
Barkfill and Pressure Plant Areas was completed by June 1999. Prior to 
placement of treated soils in the Barkfill and Pressure Plant Areas, 
the stockpiled clean rock was used as backfill for the excavation. 
Imported clean borrow was also placed on top of the rock and compacted 
prior to placement of treated soils in the excavated pits since the 
majority of clean overburden was used to backfill several unsecured 
excavation areas in 1995.
    After the first lift was removed, an additional 5,000 cubic yards 
of impacted soil under the Pressure Plant was excavated. These soils 
were loaded on the LTU for treatment in 1999 after the remaining 
buildings and infrastructure associated with wood treatment operations 
were demolished and properly disposed off-site. Soils were managed in 
the LTU for a few more years before ROD performance standards were 
achieved.
    An LTU Closure Work Plan was submitted to the EPA in February 2002 
and was approved in July 2002. The LTU closure activities were 
conducted in accordance with the approved LTU Closure Work Plan. 
Closure activities were based on the September 2000 excavated soil 
analytical results being below the ROD soil treatment goals for PCP and 
PAHs. Dioxin/furan levels calculated as TCDD TEQ remained above the ROD 
performance standards in the treated soils. Sample results ranged from 
1.0 to 5.0 microgram/kilogram ([micro]g/kg) expressed as TCDD TEQ. The 
1996 ESD specified that the treated soils may be used for fill material 
on excavated areas of the Site. If the soil contains other contaminants 
(e.g., dioxins/furans) that exceed the ROD performance standards after 
treatment, the treated soil would be isolated from groundwater and 
covered with a minimum of twelve inches at the surface to prevent 
direct contact. Institutional Controls on future land use would also be 
implemented.
    The LTU was subsequently decommissioned and closed in accordance 
with the EPA-approved closure plan. The construction, operation and 
closure of the LTU is documented in the LTU Closure Completion Report. 
The LTU liner was taken out, rinsed and disposed of off-site. The clean 
soils that were excavated to construct the berm around the LTU and 
retention pond were used to close the LTU. These soils were graded flat 
upon removal of the LTU leachate collection system, filter fabric and 
liner. Fifteen thousand cubic yards of soil used in the construction of 
the LTU were placed across the LTU area and re-contoured for drainage 
control, and future reuse of the location.
    The majority of the approximately 41 acres south of I-90 was used 
to store whitewood prior to treatment. Therefore, a location south of 
the former Pressure Plant that was determined to be clean during the 
remedial investigation was identified as a suitable location to place 
the remaining treated soils from the LTU (plus an additional 5,240 
cubic yards of drainage sand that was placed at the bottom of the LTU 
to facilitate drainage).
    Two pits were excavated in an area south of the former Pressure 
Plant for placement of the treated soils and drainage sand. Treated 
soils were placed in these excavated areas above historic groundwater 
levels. After treated soil was placed in the pits, sand and filter 
fabric were placed in the Pit Area and compacted. A twelve to fifteen-
inch cover of clean fill material was then placed over the Pit Area. 
Approximately 4,440 cys of clean fill material excavated originally 
from the Pit Area were placed as the final soil cover. The soil cover 
was placed to prevent direct contact risk with the treated soil as 
described in the Remedial Action Objectives. Cap thickness was verified 
with a pre and post excavation survey of the Pit Area.
    While no samples were taken to confirm the concentrations in the 
soils used to cover the treated soils, the area south of the former 
pressure plant was used for whitewood storage and samples collected 
during the remedial investigation at surface and depth from test pits 
in the area showed these areas to be clean. As there is no record in 
the site file showing that samples of this overburden were analyzed for 
dioxins/furans, five-point composite surface soil samples were 
collected from the soil cover from four locations on-site in June 2018 
and analyzed for dioxins/furans. The TCDD TEQs calculated for the four 
surface soil sample results ranged from 0.012 [micro]g/kg to 0.570 
[micro]g/kg--below the ROD performance standard of 1.0 [micro]g/kg.
    While the ROD performance standards for PCP and PAHs were achieved 
through biological treatment, performance standards for dioxins/furans 
expressed as TCDD TEQs (dioxin toxicity equivalents) were not. Even 
though the TCDD TEQ concentrations in the treated soils exceed the soil 
performance standards established in the 1992 ROD, the soils remedy is 
protective of human health and the environment because no exposure 
pathways exist since the treated soils have been placed above historic 
groundwater levels; have clean soil on top as a cover; and 
Institutional Controls (ICs) discussed later are in place that 
restricts land use in the 4.5 acre Treated Soils Area.

Operation and Maintenance

    No further or ongoing surface and unsaturated subsurface soil 
operation and maintenance activities are required other than 
maintaining ICs and ensuring that a protective cover remains over areas 
where treated soils have been placed. It is the responsibility of 
McFarland Cascade, the parent company of IPC, their successors and 
assigns to ensure that the integrity of the soil component of the 
remedial action is maintained as long as the treated soils at the Site 
do not allow for unlimited use and unrestricted exposure. Five 
composite samples were collected at depth from the treated soils area 
in October 2017 to determine if the treated soils met ROD performance 
standards for TCDDs. Samples collected at four of the five sample 
locations exceeded the ROD performance standards of 1.0 [micro]g/kg. 
Values ranged from 0.69 [micro]g/kg to 2.9 [micro]g/kg. These results 
support the need to continue to have Institutional Controls and a 
protective cover in place to ensure that soil remedy remains protective 
of human health and the environment.

Institutional Controls

    A Notice of Institutional Control was filed with the Gallatin 
County Clerk and Recorder in 2010 that applies covenants, conditions 
and restrictions that run with the land and are binding on IPC, their 
successors and assigns, and any subsequent interest owner of the 
property. These include restrictions on new construction and excavation 
on the 4.5-acre area where treated soils were placed. Restrictions on 
use of groundwater on all IPC property were also included as a 
restriction. These restrictions ensure protection of the integrity of 
the remedial actions. This notice and corresponding attachments are 
included with the property deed records and fulfills the land use 
restrictions specified in the 1992 ROD and 1996 ESD.
    A Controlled Groundwater Use Area was created in 2001 under State 
law that

[[Page 34845]]

includes the IPC Site and the nearby residential properties north of I-
90, east and west of L Street and south and north of Rocky Creek. The 
purpose of the Controlled Groundwater Use Area designation is to 
prevent construction of new wells, where the consumption of groundwater 
may pose a threat to human health, and to protect the groundwater 
remedy.

Five-Year Reviews

    The first five-year review of the remedial action was completed in 
September 2000. The results of this review noted that the remedies for 
soil were protective of human health and the environment because all 
accessible soils exceeding ROD performance standards had been excavated 
and placed in the LTU. At the time of the first review, the LTU had 
also successfully treated one lift, and the treatment of all of the 
contaminated soils was predicted to be complete within two years.
    The second five-year review was completed in August 2005. The 
results of this review indicated that the soil remedy continues to be 
protective of human health and the environment. The soil component of 
the remedy achieved the performance standards for PCP and PAHs as 
specified in the 1992 ROD, and the LTU was dismantled and closed. 
Dioxin/furan levels expressed as TCDD TEQs (dioxin toxicity equivalent) 
remained above the ROD performance standards, but these soils were 
placed above the historic groundwater table and covered with a minimum 
of twelve inches of soil per the 1996 ESD. A deed notification was also 
filed was filed with Gallatin County in 2004 that placed use 
restrictions on those areas where waste was left in place above levels 
that allow for unlimited use and unrestricted exposure.
    The third five-year review was completed in September 2010. The 
results of this review indicated that the remedies for soil continue to 
be protective of human health and the environment in the short-term. 
The remedy at the soils component currently protects human health and 
the environment because soils have been treated to ROD standards and 
placed back on-site with a protective cover of clean soil placed over 
these treated soils. However, in order for the remedy to be protective 
in the long-term, an enforceable Institutional Control needed to be 
placed on the property. Although a deed notification had been in place 
since 2004, it was determined to not be protective of the remedy. A 
Notice of Institutional Controls was filed with Gallatin County in 
September 2010 that follows Montana Code Annotated 76-7-201, and 
addressed the deficiencies identified in the previous deed 
notification.
    The fourth five-year review was completed in August 2015. While a 
site-wide protectiveness determination could not be made due to 
insufficient data available to evaluate the groundwater remedy, there 
were no issues or recommendations in the five-year review related to 
the soil remedy. The additional data have since been collected and 
reviewed and an addendum to the five-year review was issued on March 
11, 2019 that determined the remedy is protective of human health and 
the environment.
    The next five-year review is scheduled to be completed in September 
2020.

Community Involvement

    Prior public participation requirements have been satisfied as set 
forth in CERCLA Section 113(k), 42 U.S.C. 9613(k), and CERCLA Section 
117, 42 U.S.C. 9617. Major community involvement activities at the Site 
included establishing a local presence by meeting with property owners 
and concerned citizens. Outreach efforts included community interviews, 
fact sheets, public meetings, neighborhood meetings, public comment 
periods and website updates. The most recent fact sheet was sent out in 
November 2017 and the last public meeting was held in December 2017. 
The City and County Commissioners were briefed in December 2017 and the 
Gallatin City-County Board of Health was briefed in February 2018. The 
partial deletion of the surface and unsaturated subsurface soils 
component of the IPC Site was discussed at these meetings and presented 
in EPA's fact sheet.
    Documents in the partial deletion docket that the EPA relied on for 
recommending the partial deletion from the NPL are available to the 
public in the information repositories, and a notice of availability of 
the Notice of Intent for Partial Deletion has been published in the 
Bozeman Daily Chronicle to satisfy public participation procedures 
required by 40 CFR 300.425(e)(4).

Determination That the Site Meets the Criteria for Deletion

    The implemented soil remedy achieves the Remedial Action Objectives 
specified in EPA's 1992 ROD and the subsequent ESDs for all soil 
pathways of exposure. No further Superfund responses are needed to 
protect human health and the environment at the Site.
    The NCP (40 CFR 300.425(e)) states that a portion of a site may be 
deleted from the NPL when no further response action is appropriate. 
The EPA, in consultation with the State of Montana, has determined that 
all required response actions have been implemented for the soil 
component of the remedy and no further response action by responsible 
parties is appropriate.

List of Subjects in 40 CFR Part 300

    Environmental protection, Air pollution control, Chemicals, 
Hazardous waste, Hazardous substances, Intergovernmental relations, 
Penalties, Reporting and recordkeeping requirements, Superfund, Water 
pollution control, Water supply.

    Authority: 33 U.S.C. 1321(d), 42 U.S.C. 9601-9657; E.O. 13626, 
77 FR 56749, 3 CFR 2013 Comp., p. 306; E.O. 12777, 56 FR 54757, 3 
CFR, 1991 Comp., p. 351; E.O. 12580, 52 FR 2923, 3 CFR, 1987 Comp., 
p. 193.

    Dated: July 1, 2019.
Gregory E. Sopkin,
Regional Administrator, Region 8.
[FR Doc. 2019-15305 Filed 7-18-19; 8:45 am]
 BILLING CODE 6560-50-P