[Federal Register Volume 91, Number 119 (Tuesday, June 23, 2026)]
[Rules and Regulations]
[Pages 37319-37321]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-12544]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 268
[EPA-R08-RCRA-2025-0420; FRL-12863-02-R8]
No-Migration Variance From Land Disposal Restrictions for Clean
Harbors Grassy Mountain, Utah
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final approval.
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SUMMARY: The Environmental Protection Agency (EPA) is approving with
conditions, no-migration variances for four categories/groups of
wastes, containing up to a combined 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, Utah. These variances will
allow Clean Harbors to temporarily store treated hazardous wastes that
are awaiting LDR compliance verification in put piles within its
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 put piles 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 cell and will be subject to the conditions set out in the
Compliance Monitoring Plan section of this document.
DATES: The final approval is effective July 23, 2026.
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; and email: [email protected].
SUPPLEMENTARY INFORMATION:
I. 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?
The EPA is finalizing no-migration variances (NMVs) for up to a
combined 250 put piles at any one time for the 4 categories/groups of
wastes identified in The Petition section of this approval as requested
by Clean Harbors in their July 16, 2024 petition, for the Grassy
Mountain facility. For the reasons described in the December 31, 2025
(90 FR 61356) preamble to the proposed approval and in the Agency's
response to the three comments received on the proposal, the EPA is
finalizing the variance without alteration. 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) through (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, 40 CFR 268.6(a) describes the
components that a demonstration of no migration must address; 268.6(b)
specifies certain criteria that must be satisfied for that
demonstration, and 268.6(c) describes the monitoring program that will
be used to verify that the conditions of the NMV are being met.
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\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.''
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II. Background
A. The Petition
On July 16, 2024, Clean Harbors submitted an NMV petition to the
EPA for its Grassy Mountain facility in Tooele County, Utah, 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. In response to EPA requests following the original
November 2023 submission, Clean Harbors provided supplemental
information for the Agency's evaluation of Clean Harbors' no-migration
demonstration. The original petition and associated responses to Agency
information requests (together referred to as ``the petition'') can be
found in the docket (EPA-R08-RCRA-2025-0420).
III. Summary of Conditions for the NMV
A. Types of Wastes and Maximum Quantity of Put Piles Covered by This
NMV
Clean Harbors' no migration demonstration applies to the following
four categories/groups of wastes stored in up to a combined 250 put
piles at any one time located within the facility's Subtitle C Landfill
cell, known as ``Cell 8.''
(1) general metals (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);
(4) ammonia (D002, D004-D011).
B. Duration of Temporary Storage
While the basis for EPA's final approval is that Clean Harbors
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, this NMV is conditioned upon the temporary nature of
the put piles within Landfill Cell 8 and is intended for situations
where the put piles are used as part of an overall strategy to confirm
consistent and compliant treatment that meets the applicable LDR
treatment standards.
The Agency concludes that Clean Harbors has provided sufficient
analytical data to justify a six (6)-month duration (i.e. 180 days) 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. If an issue
arises where greater than 180 days temporary staging of a put pile is
necessary, the Utah DEQ may issue an extension, if warranted.
[[Page 37320]]
C. Required Put Pile Engineered Controls
This section describes engineered controls required for put piles,
in addition to site-wide engineered controls described in the petition
and proposed approval found in the docket under Docket ID No. EPA-R08-
RCRA-2025-0420.
All put piles must be temporarily stored in a designated area of
Landfill Cell 8 until LDR compliance has been confirmed. The put piles
must then be moved to the working face of Landfill Cell 8.
The put piles must 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 put
pile boundary. These unit-specific barriers are distinct from the
existing landfill controls for Landfill Cell 8, such as run-on and run-
off controls, that were considered in the overall prevention of
migration of hazardous constituents.
1. 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. Because the layout of the put piles is accommodated within
the standard width of a prefabricated 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 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 put pile
to prevent potential horizontal migration of the waste from the edge of
the liner.
Before placing the put piles in the temporary storage area of
Landfill Cell 8, Clean Harbors must grade the temporary storage area
where put 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.
2. Covers
Clean Harbors must 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 put 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, sustained freezing temperatures are
expected for more than one day, or 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.
3. Run-On/Run-Off Controls
Upgradient of the staging area for each put pile, Clean Harbors
must construct and/or maintain a diversion berm of sufficient height/
width to direct run-on away from each of the put piles. 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, if
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 must
include, at a minimum, ditches around the inside perimeter of Landfill
Cell 8 embankments and must remove ponded stormwater that accumulates
on top of the put piles.
4. Compliance Monitoring Plan
In accordance with 40 CFR 268.6(a)(4), Clean Harbors must maintain
at the facility, a put pile monitoring plan that includes, at a
minimum, components 1-16 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 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; and 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
verification 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 put piles or is unable to remedy any
deficiency within one (1) week of discovery, Clean Harbors must
immediately suspend receipt of waste at the affected put pile and
notify the Region 8 Administrator, in writing, within ten (10) days of
the determination that a release has occurred or that a deficiency was
unable to be remedied within one (1) week.
Clean Harbors must:
1. Review and track 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. Inspect 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. Observe 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. Perform 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 the 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
[[Page 37321]]
(e.g., liquid seeps on the waste pile slopes or emanating from its
base); and (6) cracks in the Posi-Shell[supreg].
5. Ensure 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 temperatures at
or below 32 [deg]F are expected for more than one day or for any length
of time when temperatures are below 30 [deg]F.
6. Verify that 100% coverage of Posi-Shell[supreg] is achieved over
the entire put 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. Check for loss of 100% coverage of Posi-Shell[supreg] or other
signs of cover degradation (imminent potential for loss of barrier
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 each put pile staging area.
13. Maintain or alter, as appropriate, landfill grading to prevent
put pile run-on.
14. Isolate the four waste categories/groups of put piles from each
other to prevent potential commingling.
15. Maintain landfill equipment.
16. Submit a duplicate copy of the RCRA annual report required by
40 CFR 268.6(c)(3). This will include all LDR verification sampling,
resampling, and retreatment to EPA Region 8 at: 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.
IV. Future Amendments to This NMV
If Clean Harbors anticipates needing to exceed 250 put piles at any
one time, it must request approval from EPA Region 8 Administrator
prior to creating new put piles. 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.
While this Final Approval applies only to those put piles placed
within existing Landfill Cell 8, upon permit approval of new cells,
Clean Harbors may submit to EPA Region 8 an addendum to this petition
to expand this NMV and all of its conditions and requirements, for the
put piles located within the new landfill cell if:
1. Clean Harbors is in compliance with the approved NMV;
2. The new landfill cell uses the same disposal unit engineered
controls (e.g., landfill cell interior berms for run-on and run-off
control) as approved in this variance;
3. The duration of temporary placement remains at six (6) months or
less and complies 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 cell.
Additionally, 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 the purpose of this
NMV, all changes that significantly depart from the conditions
described in the petition and proposed approval found in Docket ID No.
EPA-R08-RCRA-2025-0420 must be reported to the Region 8 Administrator
if the changes have the potential to affect migration of hazardous
constituents from the put piles:
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. A
proposed change must first be approved by the Region 8 Administrator
before taking any action.
2. If Clean Harbors discovers a site condition that does not occur
as modeled or predicted in the petition, this change must be reported,
in writing, to the Region 8 Administrator within 10 days of discovery.
The Region 8 Administrator will determine whether the reported change
from expected conditions alters the terms of the approved variance and
thus requires further action.
V. Public Comment Period
EPA announced its proposal to approve the Clean Harbors NMV
petition and provided 30-day public comment period on December 1, 2025.
The comment period closed on January 30, 2026 (90 FR 61356, December
31, 2025). EPA received three comments in response to the proposed NMV
approval. The public comments and EPA's responses are available in the
docket for this action (EPA-R08-RCRA-2025-0420). Portions of the three
comments were outside the scope of this action; EPA addresses the
relevant issues in the Response to Comments document provided in the
docket.
VI. Conclusion
The agency concludes that Clean Harbors has 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 permitted Subtitle C
hazardous waste Landfill Cell 8 while awaiting verification of
compliance with the LDR standards. Accordingly, EPA hereby approves the
NMV for Clean Harbors' Grassy Mountain facility, subject to the terms
and conditions stated herein and as presented in the petition found in
the docket.
List of Subjects in 40 CFR Part 268
Environmental protection, Hazardous waste, Variances.
Dated: June 8, 2026.
Cyrus Western,
Regional Administrator, Region 8.
[FR Doc. 2026-12544 Filed 6-22-26; 8:45 am]
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