Proposed Rule2025-24134
No-Migration Variance From Land Disposal Restrictions for Clean Harbors Grassy Mountain, Utah
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
December 31, 2025
Issuing agencies
Environmental Protection Agency
Abstract
The U.S. Environmental Protection Agency (EPA) is proposing to grant, with conditions, no-migration variances for four categories/ groups of wastes, containing up to 250 temporary disposal units ("put piles") at any one time, from the Resource Conservation and Recovery Act (RCRA) Land Disposal Restrictions (LDR) standards at Clean Harbors' Grassy Mountain (Clean Harbors) commercial treatment, storage and disposal facility (TSDF) in Tooele County, UT. These variances will allow Clean Harbors to temporarily store treated hazardous wastes that are awaiting LDR compliance verification in put piles within their Subtitle C (hazardous waste) landfill. The petitioner demonstrated, to a reasonable degree of certainty, that there will be no migration of hazardous constituents from the disposal units for as long as the wastes remain hazardous. Additionally, once LDR compliance is verified, the put piles will be disposed within the onsite RCRA hazardous waste Landfill area and will be subject to the conditions set out in the Compliance Monitoring Plan section of this document.
Full Text
<html>
<head>
<title>Federal Register, Volume 90 Issue 247 (Wednesday, December 31, 2025)</title>
</head>
<body><pre>
[Federal Register Volume 90, Number 247 (Wednesday, December 31, 2025)]
[Proposed Rules]
[Pages 61356-61361]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-24134]
========================================================================
Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
========================================================================
Federal Register / Vol. 90, No. 247 / Wednesday, December 31, 2025 /
Proposed Rules
[[Page 61356]]
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 268
[EPA-R08-RCRA-2025-0420; FRL-12863-01-R8]
No-Migration Variance From Land Disposal Restrictions for Clean
Harbors Grassy Mountain, Utah
AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of proposal to grant.
-----------------------------------------------------------------------
SUMMARY: The U.S. Environmental Protection Agency (EPA) is proposing to
grant, with conditions, no-migration variances for four categories/
groups of wastes, containing up to 250 temporary disposal units (``put
piles'') at any one time, from the Resource Conservation and Recovery
Act (RCRA) Land Disposal Restrictions (LDR) standards at Clean Harbors'
Grassy Mountain (Clean Harbors) commercial treatment, storage and
disposal facility (TSDF) in Tooele County, UT. These variances will
allow Clean Harbors to temporarily store treated hazardous wastes that
are awaiting LDR compliance verification in put piles within their
Subtitle C (hazardous waste) landfill. The petitioner demonstrated, to
a reasonable degree of certainty, that there will be no migration of
hazardous constituents from the disposal units for as long as the
wastes remain hazardous. Additionally, once LDR compliance is verified,
the put piles will be disposed within the onsite RCRA hazardous waste
Landfill area and will be subject to the conditions set out in the
Compliance Monitoring Plan section of this document.
DATES: Comments must be received on or before January 30, 2026.
ADDRESSES: You may send comments, identified by EPA-R08-RCRA-2025-0420,
by any of the following methods:
<bullet> Federal eRulemaking portal: <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>
(our preferred method). Follow the online instructions for submitting
comments.
<bullet> Email: <a href="/cdn-cgi/l/email-protection#c4aaa1b3a8a5aaa0eaaea1b7b7a184a1b4a5eaa3abb2"><span class="__cf_email__" data-cfemail="264843514a474842084c435555436643564708414950">[email protected]</span></a>.
<bullet> Mail, hand delivery or courier: Deliver your comments to
Jesse Newland, Land, Chemicals and Redevelopment Division, EPA Region
8, 1595 Wynkoop Street, Denver, Colorado 80202-1129, Mail Code: 8LCR-
RC-P, telephone number: (303) 312-6353. Courier or hand deliveries are
only accepted during the Regional Office's normal hours of operation.
The public is advised to call in advance to verify the business hours.
Special arrangements should be made of deliveries of boxed information.
<bullet> Instructions: All submissions received must include the
Docket ID No. EPA-R08-RCRA-2025-0420 for this rulemaking. Comments
received may be posted without change to <a href="https://www.regulations.gov">https://www.regulations.gov</a>,
including any personal information provided. For detailed instructions
on sending comments and additional information, see the ``Public
Participation'' heading of the SUPPLEMENTARY INFORMATION section of
this document.
FOR FURTHER INFORMATION CONTACT: Jesse Newland, Land, Chemicals and
Redevelopment Division, EPA Region 8, 1595 Wynkoop Street, Denver,
Colorado 80202-1129, mail code: 8LCR-RC-P, telephone number: (303) 312-
6353, email address: <a href="/cdn-cgi/l/email-protection#d3bdb6a4bfb2bdb7fdb9b6a0a0b693b6a3b2fdb4bca5"><span class="__cf_email__" data-cfemail="91fff4e6fdf0fff5bffbf4e2e2f4d1f4e1f0bff6fee7">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
I. Public Participation
A. Docket
EPA has established a docket for this action under Docket ID No.
EPA-R08-RCRA-2025-0420. All documents in the docket are listed in the
<a href="https://www.regulations.gov">https://www.regulations.gov</a> index.
B. Written Comments
Submit your comments, identified by Docket ID No. EPA-R08-RCRA-
2025-0420, at <a href="https://www.regulations.gov">https://www.regulations.gov</a> (our preferred method), or
the other methods identified in the ADDRESSES section. Once submitted,
comments cannot be edited or removed from the docket. 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. 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 <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
C. Submitting CBI
Do not submit information that you consider to be CBI
electronically through <a href="https://www.regulations.gov">https://www.regulations.gov</a> or email. Send or
deliver information identified as CBI to only the following address:
RCRA Document Control Officer Andy Woodward, 1595 Wynkoop Street,
Denver, CO 80202-1129, Mail Code: 8ECA-RO-E, Email:
<a href="/cdn-cgi/l/email-protection#2f5840404b584e5d4b014e414b566f4a5f4e01484059"><span class="__cf_email__" data-cfemail="a0d7cfcfc4d7c1d2c48ec1cec4d9e0c5d0c18ec7cfd6">[email protected]</span></a>, Attn: Docket ID No. EPA-R08-RCRA-2025-0420.
Clearly mark the part or all of the information that you claim to
be CBI. For CBI information in a disk or CD-ROM that you mail to EPA,
mark the outside of the disk or CD-ROM as CBI and then identify
electronically within the disk or CD-ROM the specific information that
is claimed as CBI. In addition to one complete version of the comment
that includes information claimed as CBI, a copy of the comment that
does not contain the information claimed as CBI must be submitted for
inclusion in the public docket. If you submit a CD-ROM or disk that
does not contain CBI, mark the outside of the disk or CD-ROM clearly
that it does not contain CBI. Information marked as CBI will not be
disclosed except in accordance with procedures set forth in 40 Code of
Federal Regulations (CFR) part 2.
II. General Information
A. Does this document apply to me?
This action applies only to Clean Harbors' Grassy Mountain facility
(Clean Harbors) located in Tooele County, Utah.
B. What action is the Agency taking?
On July 16, 2024, Clean Harbors submitted to EPA a no-migration
variance (NMV) petition, in accordance with 40 CFR 268.6, seeking an
[[Page 61357]]
exemption from the Land Disposal Restrictions (LDR) prohibition on land
placement of hazardous waste that does not meet the prescribed LDR
standards of 40 CFR 268.40. Because the petition demonstrated to a
reasonable degree of certainty that, for as long as the wastes remain
hazardous, there will be no migration of hazardous constituents from
the disposal units, EPA proposes to grant, with conditions, Clean
Harbors' variance from the LDR prohibition for up to 250 put piles at
any one time. If granted, the term of this NMV shall be no longer than
the term of the RCRA Subtitle C permit for the permitted Landfill.
C. What is the Agency's authority for taking this action?
Sections 3004(d) through (g) of the Resource Conservation and
Recovery Act (RCRA), 42 U.S.C. 6294(d)-(g), prohibit the land disposal
of hazardous wastes unless such wastes meet the LDR treatment standards
(``treatment standards'') established by EPA (``Agency'').
However, RCRA 3004(d)(1),\1\ and its implementing regulations found
at 40 CFR 268.6, provide an option for land disposal of hazardous waste
that does not meet the applicable treatment standards where EPA has
approved an NMV petition. Specifically, the regulations in 40 CFR
268.6(a) describe the components that a demonstration must address; 40
CFR 268.6(b) specifies certain criteria that must be satisfied for that
demonstration, and 40 CFR 268.6(c) describes the monitoring program
that will be used to verify that the conditions of the NMV are being
met.
---------------------------------------------------------------------------
\1\ RCRA 3004(d)(1)(c) states: ``. . . For the purposes of this
paragraph, a method of land disposal may not be determined to be
protective of human health and the environment for a hazardous waste
referred to in paragraph (2) . . . unless, upon application by an
interested person, it has been demonstrated to the Administrator, to
a reasonable degree of certainty, that there will be no migration of
hazardous constituents from the disposal unit or injection zone for
as long as the wastes remain hazardous.''
---------------------------------------------------------------------------
III. Background
A. No-Migration Variances and Guidance
An NMV is a formal decision that can be rendered by the EPA in
response to a petition filed with the Agency, to allow land disposal
within a particular disposal unit, of specific prohibited waste when it
has been demonstrated, ``to a reasonable degree of certainty, that
there will be no migration of hazardous constituents from the disposal
unit . . . for as long as the wastes remain hazardous.'' \2\ It must be
demonstrated, to a reasonable degree of certainty, that hazardous
constituents will not exceed Agency-approved human health-based levels
(or environmentally protective levels, if they are appropriate) beyond
the boundary of the disposal unit.\3\ In most cases, the disposal unit
boundary is defined as the outermost limit of engineered components.\4\
---------------------------------------------------------------------------
\2\ See 51 FR at 40578, November 7, 1986.
\3\ 57 FR 35941, August 11, 1992.
\4\ Id.
---------------------------------------------------------------------------
The regulatory requirements for an NMV under the RCRA LDRs were
codified in 40 CFR 268.6 in 1986,\5\ and EPA issued guidance on these
requirements in 1992. The 1992 guidance is applicable to landfills,
surface impoundments, and waste piles. While the 1992 guidance
acknowledged temporary placement of waste under an approved NMV, it did
not address the temporary placement of treated waste piles awaiting LDR
compliance verification within the boundary of a RCRA-permitted
Subtitle C (hazardous waste) landfill. In this situation, once a
treated waste pile is confirmed to meet the LDR, it is moved to the
``working face'' \6\ of the Landfill for final disposal; however, if
there is an exceedance of an LDR standard, the waste pile is returned
to the treatment process for further treatment.
---------------------------------------------------------------------------
\5\ 51 FR 40572, November 7, 1986.
\6\ The working face of a landfill is the area within a specific
cell where waste is currently being placed and compacted. It is the
designated section where waste is unloaded and daily cover is
applied at the end of each working day.
---------------------------------------------------------------------------
Any instance where a waste pile does not meet the applicable LDR
standards and an NMV has not been granted would violate LDR
requirements--hazardous waste either must meet the LDR standards or
have an approved NMV in place. To provide guidance specific to this
circumstance, the EPA issued ``Information for Petitioners Seeking a
No-Migration Variance Under the RCRA Land Disposal Restrictions for
Temporary Placement of Treated Hazardous Waste Within a Permitted
Subtitle C Landfill'' (88 FR 10894, February 22, 2023) (``2023
Guidance'') and posted it online at <a href="https://rcrapublic.epa.gov/files/14952.pdf">https://rcrapublic.epa.gov/files/14952.pdf</a>.
The 2023 guidance acknowledges the need for unique considerations
when a no migration demonstration for put piles occurs within a
Subtitle C Landfill prior to permanent disposal in the Landfill. ``EPA
expects that petitioners will be able to take advantage of existing
facility information (e.g., existing monitoring, inspections,
engineered barriers, waste analyses), where appropriate, as part of any
demonstration . . . For example, the use of temporary barriers, such as
plastic covers above and below the piles; visual monitoring and prompt
responses to possible releases; and generally good housekeeping
practices that ensure the treated waste remains in the pile during the
temporary storage period would be elements to consider. Attributes of
the permitted Landfill cell (e.g., design, existing controls,
monitoring) in which the pile or piles are located should also be
considered to the extent that they support the demonstration criteria
being applied to the piles themselves.'' (86 FR 5192, January 19,
2021).
Approval of an NMV petition is delegated to the EPA Regional
Administrator for the EPA Region in which the waste management unit is
located. States are not authorized to implement the NMV authority;
however, the EPA consulted with Utah prior to proposing to grant this
NMV. The final decision will be published in the Federal Register. If
granted, the term of an NMV may be no longer than the term of the
existing RCRA Subtitle C permit for the Landfill. Any petitions to
renew an NMV must undergo notice and comment procedures. An NMV that
has been issued can be revoked for cause, including any migration of
hazardous constituents.
40 CFR 268.6(e) acknowledges the potential for post-approval
changes in conditions at the no migration unit(s) and/or the
environment around the no migration unit(s). For purposes of these
variances, these changes must be reported to the Regional Administrator
of Region 8 (Region 8 Administrator) if these changes significantly
depart from the conditions described in the variances and affect the
potential for migration of hazardous constituents from the units as
follows:
1. If Clean Harbors plans to make changes to the unit(s)' design,
construction, or operation, such a change must be proposed, in writing,
and include a demonstration to the Region 8 Administrator at least 30
days prior to making the change. The Region 8 Administrator will
determine whether the proposed change invalidates the terms of the
approved variance and will determine the appropriate response. Any
change must be approved by the Region 8 Administrator prior to being
made.
2. If Clean Harbors discovers that a condition at the site which
was modeled or predicted in the petition does not occur as predicted,
this change must be reported, in writing, to the Region 8 Administrator
within 10 days of discovering the change. The Region 8 Administrator
will determine whether the reported change from the terms of
[[Page 61358]]
the variance requires further action, which may include termination of
waste acceptance and revocation of the petition, petition
modifications, or other responses.
B. Clean Harbors' Petition for No Migration Variances
On July 16, 2024, Clean Harbors' Grassy Mountain facility (Clean
Harbors) in Tooele County, Utah, submitted an NMV petition to the EPA
seeking an exemption from the LDR prohibition on placing hazardous
waste on the ground, if that waste does not meet the prescribed LDR
standards of 40 CFR 268.40, by demonstrating that for as long as the
waste remains hazardous, there will be no migration of hazardous
constituents from the disposal units. Clean Harbors' no migration
demonstration applies to 250 put piles at any one time located within
the facility's Subtitle C Landfill cell, known as ``Cell 8,'' Clean
Harbors also requested that this variance proactively apply to future
put piles of identical waste characteristics that would be staged in
future proposed and permitted Subtitle C Landfill cells, known as
``Cells 9 to 13.''
While this Notice of Proposal to Grant applies only to those put
piles placed within existing Landfill Cell 8, upon permit approval of
Landfill Cells 9, 10, 11, 12, and/or 13, Clean Harbors may submit to
the Agency, an addendum to this petition to expand this NMV and all of
its conditions and requirements, to the put piles within the new
landfill cell(s) if:
1. Clean Harbors is in compliance with the approved NMV,
2. The new landfill cell(s) use the same disposal unit engineered
controls concept (e.g., landfill cell interior berms for run-on and
run-off control) as approved in this variance,
3. The duration of temporary placement must remain at six (6)
months or less and comply with the conditions established herein,
4. The waste categories remain the same, and
5. The monitoring program (e.g., groundwater monitoring) is
expanded to include the new landfill cells.
In response to EPA requests following the original July 2024
submission, Clean Harbors provided supplemental information for the
Agency's evaluation of Clean Harbors' no-migration demonstration. The
original petition and the response to Agency information requests
(together referred to as ``the petition'') can be found in the docket
(EPA-R08-RCRA-2025-0420).
Clean Harbors' petition included the following components: (a)
facility description, (b) site characterization, (c) identification and
characterization of the affected wastes, (d) disposal unit engineered
controls, (e) duration of temporary staging, (f) air pathway
mitigation, (g) monitoring program, and (h) uncertainty analysis. These
are discussed below.
IV. Basis for the EPA's Proposed Determination
A. Components of the Petition
1. Facility Description
Clean Harbors' Grassy Mountain facility (EPA ID Number:
UTD991301748) is located three miles East and seven miles north of
Knolls, Tooele County, Utah. The mean annual precipitation in the
region is approximately 7.9 inches and 0.5 inches for rain and snow,
respectively. The permitted facility, which covers an area of
approximately 640 acres, with an additional 0.5-mile buffer along the
perimeter, is expected to be in operation for more than ten years. A
RCRA Part B Permit (hazardous waste permit) was issued by the EPA in
1998 and later transferred to the State of Utah for subsequent
renewals. The latest renewal (signed on October 4, 2023) for a 10-year
term, was issued by the Utah Division of Waste Management and Radiation
Control.
Clean Harbors' hazardous waste permit authorizes the facility to
manage liquid, solid or semisolid hazardous waste and non-hazardous
industrial waste. The facility has three active hazardous waste
Landfill cells, two of which are also authorized for disposal of PCB
waste. Waste treatment services provided at the facility include
solidification, stabilization and macro/microencapsulation of hazardous
waste and evaporation of non-hazardous wastewater. Solid, liquid, and
sludge wastes are accepted in containerized or bulk loads (e.g., roll-
off containers); however, the wastes that would generally be covered
under this NMV are received as bulk loads.
2. Site Characterization/Unit Description
Currently, all put piles are temporarily stored in Landfill Cell 8
until LDR compliance has been confirmed, then compliant piles are moved
to the working face of Landfill Cell 8. Put piles that fail to meet LDR
standards are retreated and subsequently returned to a put pile in
Landfill Cell 8. It is important to note that this variance, if
approved, will apply to the each put pile and not to Landfill Cell 8.
As stated in the 2023 guidance, where multiple piles contain the same
or similar wastes, the petition can address these units as a group
where such piles are effectively being managed as a single unit. As
such, the Agency proposes that each of the four categories/groups of
treated wastes described in the Waste Characterization section below
will have its own variance; however, each put pile within each
category/group will be assigned its own unit boundary.
Each put pile (approximately 35-cubic yards) is placed on a
polyethylene barrier sheet (20-mil minimum thickness) within Landfill
Cell 8. Because wastes are treated and presumed to meet LDR standards
prior to placement in Landfill Cell 8, and storage in the petitioned
units is temporary, the Agency has established unit boundaries (i.e.,
points of compliance for no-migration purposes) for each of the
petitioned units to account for existing Landfill controls and
appropriate deviations from the waste pile liner design standards of 40
CFR 264.251.
The Agency proposes that the unit boundaries extend vertically one
inch below the 20-mil thick polyethylene liner and laterally one foot
short of the outermost surface edges of the 20-mil thick polyethylene
liner. Air dispersion compliance will be demonstrated at the outer
thickness of the Posi-Shell[supreg] liner.
3. Waste Characterization
In accordance with 40 CFR 268.6(a)(1), Clean Harbors indicated that
the following four categories/groups of hazardous wastes and their
underlying hazardous constituents (UHCs) found at 40 CFR 268.48 could
be temporarily placed in the put piles after treatment to meet LDR
standards: (1) general metals (D002, D004-D011); (2) cyanide/sulfide
with metals (D002, D004 through D011, F006 through F012, F019); (3)
high-chromium wastes (D002, D004 through D011, F006); and (4) ammonia
(D002, D004-D011). These four waste categories/groups may be stabilized
via treatment with any combination of the following reagents to prevent
leaching: cement kiln dust, water, calcium polysulfide, ferrous
sulfate, and sodium hypochlorite. The stabilization processes performed
include the LDR technology standards for chemical oxidation (CHOXD),
neutralization (NEUTR), chemical reduction (CHRED) and deactivation
(DEACT).
Clean Harbors' hazardous waste treatment process for the four waste
categories/groups is found in section 7, ``Waste Treatment Process'' of
the facility's Waste Analysis Plan (WAP) dated July 25, 2025, available
on the Utah Department of Environmental
[[Page 61359]]
Quality website at <a href="https://deq.utah.gov/businesses-facilities/rcra-part-b-hazardous-waste-permit-clean-harbors-grassy-mountain-llc">https://deq.utah.gov/businesses-facilities/rcra-part-b-hazardous-waste-permit-clean-harbors-grassy-mountain-llc</a>. The
following summary cites directly from this WAP. The hazardous waste
treatment processes include solidification, stabilization and/or
oxidation/reduction. Solidification is performed on wastes containing
free liquids. Pozzolans and other appropriate materials are used to
chemically fix the liquid. This process may also be used to neutralize
a waste stream and meet the LDR technology standard of neutralizing and
deactivating. Pre-treatment analyses of the wastes are required to
determine compatibility with the pozzolanic reactant. The initial
analysis, including fingerprint analysis, and compatibility testing is
done prior to treatment. A post-treatment analysis using a paint filter
test is performed to ensure that all free liquids have been chemically
reacted, and the mixture is suitable for disposal in the Landfill.
4. Uncertainty Analysis
40 CFR 268.6(b)(5) requires the petitioner to include an analysis
to identify and quantify any aspects of the demonstration that
contribute significantly to uncertainty. The analysis must include an
evaluation of the consequences of predictable future events, including,
but not limited to, earthquakes, floods, severe storm events, droughts,
or other natural phenomena. This analysis has already been performed in
conjunction with Clean Harbors' approved RCRA Part B permit for the
broader landfill and as such, the Agency accepts Clean Harbors'
uncertainty analysis as presented in the petition located in the
docket.
5. No-Migration Demonstration
The bases for the EPA's proposed conclusion that Clean Harbors has
demonstrated to a reasonable degree of certainty that no hazardous
constituents will migrate from the put piles for as long as the wastes
remain hazardous are discussed in this section. Although wastes are
treated with the intent of meeting the RCRA LDR standards prior to
being placed in put piles, this NMV is a safeguard to ensure that any
temporary storage of treated hazardous waste complies with statutory
and regulatory standards, particularly in those instances where a
treated hazardous waste placed in a temporary waste pile does not meet
LDR standards. This NMV is conditioned upon the temporary nature of the
put piles within Landfill Cell 8 and is intended for situations where
the temporary waste piles are used as part of an overall strategy to
confirm consistent and compliant treatment that meets the applicable
LDR treatment standards.
Where reasonable, the Agency considered existing landfill design
and operating requirements (40 CFR 264.301) that include run-on and
run-off controls to prevent the migration of hazardous constituents
beyond the designated unit boundary. Additional information including
monitoring data and discussions regarding the temporary nature of these
put piles (i.e., duration of storage), testing for verification of
treatment effectiveness, retreatment protocols and engineered controls,
as referenced in this section, is available in the petition or
supplemental information in the RCRA regulatory docket for today's
document.
i. Treatment effectiveness. As required by 40 CFR 268.6(a)(2),
Clean Harbors characterized the subject wastes, post-treatment, to
determine if LDR standards were met. Analytical data was provided for
January 2022 through March 2024 for each category of hazardous waste.
Analyses were performed for compliance with the 40 CFR 268.48 Universal
Treatment Standards (UTS) for all UHCs, including antimony (Sb),
arsenic (As), barium (Ba), beryllium (Be), cadmium (Cd), chromium (Cr),
lead (Pb), nickel (Ni), selenium (Se), silver (Ag), thallium (Tl),
vanadium (V), zinc (Zn), mercury (Hg), and cyanides (CN).
Clean Harbors provided analytical data indicating that
approximately 95% of all waste treated met the LDR standards following
the first treatment procedure, without the need for additional
treatment; however, in the early 2020's the passing rate decreased, due
to some wastes having higher than expected concentrations of certain
constituents. Clean Harbors reanalyzed incoming waste streams to adjust
their treatment recipe/methods. Continued improvement in treatment
effectiveness was demonstrated from 2022 to the present. In 2022, 316
waste piles were treated and analyzed and 282 met post-treatment LDR
standards, resulting in a net ``pass rate'' of 89.2%. In 2023, 345
waste piles were treated and analyzed and 317 met post-treatment LDR
standards (91.9%). From January to March of 2024, 113 waste piles were
treated and analyzed and 108 met post-treatment LDR standards (95.6%).
By the end of March 2024, 126 waste piles were treated and analyzed and
121 met post-treatment LDR standards (96%). The results of these waste
analyses are summarized in table A-1 of the petition located in the
docket for today's document.
The sampling methodology used by Clean Harbors to verify compliance
with LDR standards for the wastes post-treatment was deemed adequate
for this NMV because: (1) verification samples were collected in
accordance with the facility's approved WAP that requires sample(s) be
collected from each batch of treated waste (see section 7.1 of the WAP:
one batch is generally equivalent to the volume of one put pile; (2)
the samples were collected and analyzed over extended periods of time
to demonstrate long-term compliance history; (3) the treated wastes
were analyzed for compliance with UTS for UHCs likely to be found in
the wastes; and (4) pass or fail determinations for LDR compliance were
presented for all wastes sampled and net pass rates were calculated
from these determinations as described in the preceding paragraph. The
current pass rate for temporarily staged subject waste piles exceeds
95%, demonstrating that these put piles do not routinely receive
treated wastes that do not meet applicable LDR standards, thereby
supporting the ``temporary'' nature of storage for each waste category.
The Agency concludes that Clean Harbors has provided sufficient waste
characterization information in its petition to support the conclusion
of treatment effectiveness.
ii. Duration of temporary storage. When the LDR standard is
confirmed to ``pass,'' the put pile is moved to the working face of
Landfill Cell 8 for final disposal generally within 45 days of initial
placement of the put pile. If the LDR standard ``fails,'' the RCRA
permit requires the put pile to either be resampled or retreated
immediately. Resampling consists of two grab samples per batch of waste
to verify the results of the initial sample. If one or both resamples
fail, the waste is retreated. If both samples pass, the put pile is
moved to the working face of Landfill Cell 8 for final disposal.
Alternatively, after an LDR ``fail,'' Clean Harbors may choose to
retreat the waste without re-sampling to verify the initial result.
However, if the failed sample indicates that the concentrations of the
UHCs are decreasing, possibly due to additional curing, a third
confirmation sample is collected and analyzed. The end result of a
multi-stage process for sampling and retreating is that a few waste
piles may remain temporarily staged even after an LDR fail if the
analytical data indicates additional curing time is appropriate. Clean
Harbors requested up to six (6) months duration for temporary staging
of a put pile to account for the retreatment and curing process. The
Agency concludes
[[Page 61360]]
that Clean Harbors has provided sufficient analytical data to justify a
six (6)-month duration for storage of a put pile from the time the pile
is first staged until final disposal in the working face of the
Landfill Cell 8.
iii. Disposal unit engineered controls. This section describes
existing and proposed put pile liners, put pile covers, and run-off/
run-on controls. Man-made barriers or engineered systems (e.g., liner
systems) alone generally will not meet the ``no migration'' standard.
This is not the case for temporary land-based storage of treated waste
as is being considered in this document. The containment of hazardous
waste within engineered barriers is considered in making the ``no
migration'' demonstration for waste awaiting the results of
verification sampling after treatment, provided that wastes are to be
removed after a reasonably short storage period that may be
conservatively projected to be well before the failure of the
engineered barrier system.\7\ Because Clean Harbors' temporary storage
for each put pile must not exceed six (6) months, and the lifespan of
the engineered barriers described below extends into multiple decades
with appropriate operational controls to prevent rips or tears,
excluding the Posi-Shell[supreg] system which remains for the duration
of temporary storage, the Agency concurs that Clean Harbors' use of the
following barriers will prevent migration of hazardous constituents via
infiltration, lateral migration (e.g., erosion/surface water
interaction or movement of infiltration), and air dispersion/
particulate loss.
---------------------------------------------------------------------------
\7\ No Migration Variances to the Hazardous Waste Land Disposal
Prohibitions: A Guidance Manual for Petitioners, at 4, EPA Office of
Solid Waste, July 1992, EPA-530-R92-023.
---------------------------------------------------------------------------
The put piles will be encapsulated (liner below and Posi-
Shell[supreg] atop) by the unit-specific engineered barriers discussed
below to prevent migration of hazardous constituents beyond the waste
pile boundary. These unit-specific barriers are distinct from the
existing landfill controls, such as run-on and run-off controls, that
were considered in the overall prevention of migration of hazardous
constituents.
Liners
A liner of at least 20-mil thickness polyethylene geomembrane must
be used as a barrier to vertical and lateral migration for the put
piles. The liner beneath the pile will provide a barrier for vertical
migration. The Agency agrees that a minimum of 20-mil thickness barrier
is sufficient for this temporary application that will last six (6)
months or less. Because the layout of the put piles is accommodated
within the standard width of a pre-fabricated geomembrane roll, the
liner must be one solid piece without the need for welding of seams.
The lack of seams lends to additional assurance that migration of
hazardous constituents will not migrate through a broken seam. The
Agency concludes that a liner of at least 20-mil thickness, in
conjunction with the inspection program described in the Compliance
Monitoring Program section, is appropriate for use in this temporary
disposal scenario; however, there must always be at least 12 inches of
the liner visible on all sides of the waste pile to prevent potential
migration of the waste from the edge of the liner.
Covers
Clean Harbors will use a Posi-Shell[supreg] cover to act as a rain
and wind barrier for put piles, to ensure no migration of hazardous
constituents from the waste piles occurs via lateral migration or air
pathways. Posi-Shell[supreg] is a spray-applied mortar applied as a
coating to the surface of the put piles, with a minimum cover thickness
of \3/8\-inch. Because Posi-Shell[supreg] is a mortar, curing is
necessary to allow it to harden. Curing typically occurs within 12-24
hours in dry weather, forming a relatively impermeable thin layer of
durable, hardened mortar. However, if moderate to heavy rainfall occurs
unexpectedly or is imminent, or if sustained freezing temperatures are
expected for more than one day or if the temperature falls below 30
[deg]F, the Posi-Shell[supreg] will not harden sufficiently. During
these times of inclement weather, Clean Harbors must temporarily cover
the put piles with polyethylene sheeting of at least 20-mil thickness,
anchored with sandbags around its edges, until the adverse weather
conditions abate, and the Posi-Shell[supreg] coating can be applied.
Within twenty-four (24) hours of weather conditions amenable to Posi-
Shell[supreg] application, Clean Harbors must apply the coating.
To ensure Posi-Shell[supreg] is appropriate for put pile covering,
the Agency reviewed several case studies provided by Clean Harbors
where Posi-Shell[supreg] was demonstrated to prevent erosion, air
dispersion, infiltration of rainwater, and overall migration of wastes.
Table 2 in the petition located in the docket summarizes these case
studies.
The Agency concludes that Posi-Shell[supreg], or under the limited
inclement weather circumstances described above, a minimum 20-mil
polyethylene sheeting cover, will serve as an appropriate barrier to
protect the put pile from wind dispersion, erosion and rainwater
infiltration.
Run-On/Run-Off Controls
Before placing the put piles in the temporary storage area of
Landfill Cell 8, Clean Harbors must grade the temporary storage area
where waste piles will be located. The grading must be relatively flat
but with a slight positive grade to preclude ponding of water on the
polyethylene liners. If one does not yet exist, a diversion berm of
sufficient height/width to direct run-on away from the area must be
constructed upgradient of the staging area. As Landfill Cell 8 is
filled, if the waste grade changes adjacent to the put pile temporary
storage area, additional diversion berms must be added, where
necessary, to divert stormwater run-on and run-off to isolate the
staging area on the working face of Landfill Cell 8. To control run-
off, in addition to the Posi-shell[supreg] coating, Clean Harbors will
include depressions in the waste and ditches around the inside
perimeter of Landfill Cell 8 embankments. In combination with General
Surrounding Area Engineered Controls described below, these controls
must be constructed and operated to contain the water volume of a 24-
hour, 100-year storm event.
iv. General surrounding area engineered controls. All put piles are
temporarily stored in a designated area of Landfill Cell 8 until LDR
compliance has been confirmed. The put piles are then moved to the
working face of Landfill Cell 8. Landfill Cell 8 has a liner system
consisting of: (1) a bottom 60-mil textured high density polyethylene
(HDPE) liner atop a 3-foot-thick compacted clay layer with a hydraulic
conductivity of less than 1.7 x 10-7 cm/sec; (2) a double-sided
geocomposite leak detection system drainage layer; (3) a top composite
liner consisting of geosynthetic clay between two 80-mil textured HDPE
liners; (4) a double-sided geocomposite leak collection system; and (5)
a 2-foot thick cover layer. Stormwater run-on controls include
diversion channels and embankments up-gradient and within active
portions of the Landfill designed to contain a 24-hour, 100-year
rainfall event.
v. Groundwater monitoring. Clean Harbors has a groundwater
monitoring well network at the facility that currently includes four
(4) upgradient monitoring wells and 56 downgradient monitoring wells.
In particular, Landfill Cell 8 has five (5) downgradient monitoring
wells in its proximity. The wells are monitored semi-annually
[[Page 61361]]
under the RCRA detection monitoring program in the facility's RCRA Part
B permit for the analytes set forth in Attachment VII-3. This
attachment is in the docket. The Utah Department of Environmental
Quality reviewed Clean Harbors' groundwater monitoring data and advised
EPA that no hazardous constituents have been detected above their
respective health-based levels within the permit cycle.
vi. Compliance monitoring plan. 40 CFR 268.6(a)(4) requires a
petition to include a monitoring plan to verify continued compliance
with the conditions of the NMV. The monitoring plan must be designed to
detect migration ``at the earliest practicable time.'' The plan must
include frequent visual monitoring and prompt responses to possible
releases; and generally good housekeeping practices that ensure the
treated waste remains in the pile during the temporary storage
period.\8\ The monitoring plan must also include a discussion of the
sampling and analysis of the treated waste that determines when the
temporary waste pile will be moved to the working face of the landfill
for final disposal.
---------------------------------------------------------------------------
\8\ Information for Petitioners Seeking a No-Migration Variance
Under the RCRA Land Disposal Restrictions for Temporary Placement of
Treated Hazardous Waste Within a Permitted Subtitle C Landfill EPA
Office of Resource Conservation and Recovery, February 2023, <a href="https://rcrapublic.epa.gov/files/14952.pdf">https://rcrapublic.epa.gov/files/14952.pdf</a>.
---------------------------------------------------------------------------
Clean Harbors must maintain at the facility a put pile monitoring
plan that includes, at a minimum, components (1-15) below, many of
which were included by Clean Harbors in the petition and the Agency
adopts as proposed.
Deficiencies identified during inspection must be remedied/repaired
to ensure no migration of hazardous constituents occurs. Deficiencies
may include but are not limited to: cracking, breakdown or insufficient
application of the Posi-Shell cover; gaps, tears or holes in plastic
sheeting utilized for the management of the unit; presence of
stormwater run-on flow and/or ponded water; visibly exposed waste; poor
overall pile condition. Deficiencies must be remedied within one (1)
week of discovery and remedies must be recorded in the facility's
operating record.
Deficiencies described by this section must be remedied regardless
of whether Clean Harbors determines that a migration of hazardous
constituents has occurred or may have occurred, if LDR compliance
analyses of the waste in the unit is not yet available. If Clean
Harbors determines that there has been a migration of hazardous
constituents from any of the units, or is unable to remedy any
deficiency within one (1) week of discovery, Clean Harbors must
immediately suspend receipt of prohibited waste at the put pile and
notify the Region 8 Administrator, in writing, within ten (10) days of
the determination that a release has occurred.
1. Review and tracking of LDR standard ``pass rates'' for put
piles. To ensure that the waste piles are only being ``temporarily
stored,'' as described in the February 2023 guidance, if the failure
rate of the initial verification test for treated put piles exceeds 5%
in a calendar month, Clean Harbors must conduct a root cause analysis
and adjust the treatment protocol for the affected category of waste.
2. Inspection of the temporary staging area for put piles prior to
deploying the 20-mil polyethylene liner. The underlying area must be
free of large or rigid objects that may damage the liner.
3. Observing that the liner is not displaced or damaged during
placement of the waste piles on the liner to confirm the integrity of
the liner beneath a waste pile. A damaged liner must be replaced with a
new liner.
4. Daily inspection of covered waste piles to verify integrity of
the liner, cover, and overall pile condition. Inspectors must, at a
minimum, check for (1) signs of stormwater run-on flow that has or is
migrating towards a put pile, or other signs of potential for put pile
erosion, undermining, or washout of the waste encapsulation barriers;
(2) damage from strong winds, heavy rain, or other extreme weather
events (e.g., in particular, causing holes, uplift, or other breaches
in the Posi-Shell[supreg] cover) within 24 hours of such event; (3)
visible exposed waste; (4) releases of waste (washout/undermining,
displacement/movement of pile such as shifting or slumping, windblown
waste particles, etc.); (5) other indications of potential for
migration or actual observed migration of hazardous constituents from
the pile (e.g., liquid seeps on the waste pile slopes or emanating from
its base); and (6) cracks in the Posi-Shell[supreg].
5. Appropriate Posi-Shell[supreg] application. Adhering to
inclement weather application prohibitions as recommended by the
manufacturer. If a waste pile is unable to be immediately covered with
a Posi-Shell[supreg] (e.g., moderate to heavy rainfall occurs
unexpectedly or is imminent), the waste pile must be temporarily
covered with polyethylene sheeting of at least 20-mil thickness and
anchored with sandbags around its edges until the adverse weather
conditions abate and the Posi-Shell[supreg] coating can then be
applied. Posi-Shell[supreg] should not be applied when sustained
freezing temperatures are expected for more than one day or during
temperatures below 30 [deg]F.
6. Verify 100% coverage of Posi-Shell[supreg] is achieved over the
entire waste pile (no bare or thin spots).
7. Confirm that the minimum \3/8\-in. thickness of Posi-
Shell[supreg] is achieved.
8. Confirm that the Posi-Shell[supreg] cover is sufficiently set
(hardened) before a moderate to heavy rainfall event.
9. Promptly re-apply Posi-Shell[supreg] cover if any deficiencies
are identified during application, including but not limited to lack of
coverage, thickness, or hardening.
10. Checking for loss of 100% coverage of Posi-Shell[supreg], or
other signs of cover degradation (imminent potential for loss of
effectiveness or thickness).
Landfill Cell 8-specific remediation requirements:
11. Remove ponded water on the landfill surface that could affect
the put piles.
12. Modify, as needed, run-on controls to continue to divert
surface water around the waste pile staging area.
13. Maintain or alter, as appropriate, landfill grading to prevent
put pile run-on.
14. Isolate the four categories/groups of put piles from each
other.
15. Maintain landfill equipment.
V. Conclusion
The Agency proposes that Clean Harbors has successfully
demonstrated, to a reasonable degree of certainty, that there will be
no migration of hazardous constituents beyond the unit boundary for
treated hazardous wastes temporarily stored in put piles within their
permitted Subtitle C hazardous waste Landfill Cell 8 while awaiting LDR
compliance verification.
Therefore, EPA proposes to grant, with conditions, no-migration
variances for the four categories/groups of wastes designated herein,
containing up to 250 put piles at any one time at Clean Harbors' Grassy
Mountain TSD.
Cyrus M. Western,
Regional Administrator, Region 8.
[FR Doc. 2025-24134 Filed 12-30-25; 8:45 am]
BILLING CODE 6560-50-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on December 31, 2025.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.