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Proposed Rule2026-02346

US Ecology Nevada, Inc. High Mercury Subcategory Wastes Land Disposal Restrictions Variance

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Published

February 6, 2026

Issuing agencies

Environmental Protection Agency

Abstract

The Environmental Protection Agency (EPA) is proposing to grant, with conditions, US Ecology Nevada Inc.'s (USE) petition for a site-specific treatability variance from the Resource Conservation and Recovery Act (RCRA) Land Disposal Restrictions (LDR) treatment standards. USE's petition is for treatment and disposal of elemental mercury waste generated from retorting high mercury waste in accordance with the LDR technology-based standard of RMERC. The EPA believes that the petition demonstrates that the LDR standard for placing elemental mercury generated from RMERC back into commerce for reuse is inappropriate and the treatment variance is sufficient to minimize threats to human health and the environment posed by land disposal of the waste. If the variance is granted, the existing LDR treatment standard of RMERC will continue to apply to high mercury hazardous wastes, but the elemental mercury generated from this process will be treated and land disposed subject to specified conditions at both Bethlehem Apparatus in Hellertown, Pennsylvania and USE's Beatty, Nevada, Subtitle C treatment, storage, and disposal (TSD) facility where treated mercury wastes will be disposed in a designated monofill.

Full Text

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<title>Federal Register, Volume 91 Issue 25 (Friday, February 6, 2026)</title>
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[Federal Register Volume 91, Number 25 (Friday, February 6, 2026)]
[Proposed Rules]
[Pages 5400-5408]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-02346]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 268

[EPA-HQ-OLEM-2025-2038; FRL-8504-02-OLEM]
RIN 2050-AH21

US Ecology Nevada, Inc. High Mercury Subcategory Wastes Land
Disposal Restrictions Variance

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
grant, with conditions, US Ecology Nevada Inc.'s (USE) petition for a
site-specific treatability variance from the Resource Conservation and
Recovery Act (RCRA) Land Disposal Restrictions (LDR) treatment
standards. USE's petition is for treatment and disposal of elemental
mercury waste generated from retorting high mercury waste in accordance
with the LDR technology-based standard of RMERC. The EPA believes that
the petition demonstrates that the LDR standard for placing elemental
mercury generated from RMERC back into commerce for reuse is
inappropriate and the treatment variance is sufficient to minimize
threats to human health and the environment posed by land disposal of
the waste. If the variance is granted, the existing LDR treatment
standard of RMERC will continue to apply to high mercury hazardous
wastes, but the elemental mercury generated from this process will be
treated and land disposed subject to specified conditions at both
Bethlehem Apparatus in Hellertown, Pennsylvania and USE's Beatty,
Nevada, Subtitle C treatment, storage, and disposal (TSD) facility
where treated mercury wastes will be disposed in a designated monofill.

DATES: Comments must be received on or before March 9, 2026.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OLEM-2025-2038, 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> Mail: U.S. Environmental Protection Agency, EPA Docket
Center, Office of Land and Emergency Management Docket, Mail Code
28221T, 1200 Pennsylvania Avenue NW, Washington, DC 20460.
<bullet> Hand Delivery or Courier: EPA Docket Center, WJC West
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004.
The Docket Center's hours of operations are 8:30 a.m.-4:30 p.m. Eastern
time, Monday-Friday (except Federal Holidays).
Instructions: All submissions received must include the Docket ID
No. 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 on the rulemaking process, see the ``Public Participation''
heading of the SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: Bethany Russell, Waste
Characterization Branch, Waste Identification, Notice, and Generators
Division, Office of Resource Conservation and Recovery (5304P),
Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington,
DC 20460; telephone number: (202) 566-2233; email address:
<a href="/cdn-cgi/l/email-protection#deacabadadbbb2b2f0bcbbaab6bfb0a79ebbaebff0b9b1a8">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION:

I. Public Participation

A. Docket

EPA has established a docket for this action under Docket ID No.
EPA-HQ-OLEM-2025-2038. All documents in the docket are listed in the
<a href="https://www.regulations.gov">https://www.regulations.gov</a> index. Publicly available docket materials
are available either electronically at <a href="https://www.regulations.gov">https://www.regulations.gov</a> or
in hard copy at the EPA Docket Center. The Public Reading Room for the
docket is open from 8:30 a.m. to 4:30 p.m. Eastern, Monday through
Friday, excluding holidays. The telephone number for the Public Reading
Room and Docket Center is (202) 566-1744.

B. Written Comments

Submit your comments, identified by Docket ID No. EPA-HQ-OLEM-2025-
2038, 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. 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 <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:
ORCR Document Control Officer, Mail Code 5305-P, Environmental
Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460;
Attn: Docket ID No. EPA-HQ-OLEM-2025-2038.
Clearly mark the part or all the information that you claim to be
CBI. For CBI information in a disk or CD-ROM that you mail to the 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 elemental mercury treated at Bethlehem
Apparatus Hellertown, Pennsylvania and land disposed at USE's facility
located at Highway 95, 11 Miles South of Beatty, Beatty, Nevada 98003.

B. What action is the Agency taking?

On September 22, 2025, the EPA received a complete petition from
USE requesting a variance from the existing

[[Page 5401]]

prohibition on land disposal of elemental mercury (metallic mercury,
Hg(0)) generated from the treatment of waste codes D009 and U151 high
mercury subcategory (high mercury wastes) within the United States.
High mercury wastes are those containing a concentration of greater
than 260 mg/kg mercury. The LDR of 40 CFR 268.40 requires RMERC for
treatment of waste codes D009 and U151 high mercury wastes. RMERC is
the technology code for retorting or roasting in a thermal processing
unit capable of volatilizing mercury for recovery/reclamation (see 40
CFR 268.42). The regulations do not authorize the land disposal of the
elemental mercury reclaimed from the RMERC process. Instead, the LDR
treatment standard requires elemental mercury reclaimed from these
wastes be legitimately recycled (see 40 CFR 260.43) by placing the
elemental mercury into commerce for use or reuse as an effective
substitute for a commercial chemical product (see 261.1(c)(5)). When
the recyling requirement for elemental mercury was established, there
was a balanced market for elemental mercury. However, the supply of
reclaimed elemental mercury presently exceeds the market demand and
will continue to exceed market demand for the foreseeable future, and,
for that reason, excess elemental mercury generated from RMERC is being
stored at authorized sites across the country. In this action, the EPA
is proposing to provide USE for their Beatty, Nevada facility, a
variance from the requirement that elemental mercury reclaimed from
RMERC of D009, U151, or Bevill-exempt high mercury wastes generated in
the U.S. gold mining industry \1\ be placed into commerce.
Specifically, the EPA is proposing to grant, with conditions, USE's
petition for a variance pursuant to 40 CFR 268.44 to allow land
disposal of elemental mercury converted to mercury sulfide powder that
is then blended with linear low-density polyethylene (LLDPE) and
extruded as a monolith into an impermeable/non-reactive container that
is placed into a future permitted monofill located at USE's facility in
Beatty, Nevada. At the time of this proposed approval, USE has an
agreement with Bethlehem Apparatus to perform the treatment portion of
this process. See section VII., Future Amendments to this Variance, for
procedures that may allow USE to retain this variance if USE moves any
portion of the treatment process from Bethlehem Apparatus's Hellertown,
Pennsylvania location.
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\1\ The issue has arisen that U.S. gold mining Bevill-exempt
high mercury waste does not carry a waste code because of the Bevill
exemption. Although exempt, Bevill waste is like D009/U151 wastes in
that it must be retorted to extract the elemental mercury to meet
DOE's acceptance criteria. After retorting, the prohibition on land
disposal of elemental mercury remains and is unaffected by the
Bevill exemption.
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C. What is the Agency's authority for taking this action?

Sections 3004(d) through (g) of 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 the
EPA (the Agency). Section 3004(m) of RCRA, 42 U.S.C. 6924(m) requires
the EPA to set levels or methods of treatment, if any, that
substantially diminish the toxicity of the waste or substantially
reduce the likelihood of migration of hazardous constituents from the
waste, so that short-term and long-term threats to human health and the
environment are minimized.
When facilities generate hazardous wastes that cannot be treated to
the specified levels or when it is technically inappropriate for such
wastes to undergo the prescribed treatment, generators or treaters of
hazardous waste can apply for a variance from an LDR treatment
standard. See 51 FR at 40605-40606, November 7, 1986, and 62 FR 64504,
December 5, 1997. The requirements for an LDR treatment variance are
found at 40 CFR 268.44 and LDR variance petitioners must follow the
procedures in 40 CFR 260.20. Of note, 40 CFR 268.44(k) cross-references
compliance with 40 CFR 268.7 for testing, tracking and recordkeeping
requirements for generators, reverse distributors, treaters and
disposal facilities.
In this case, EPA is proposing to act pursuant to 40 CFR 268.44(h)
because it finds that the existing requirement is inappropriate, even
though the treatment is technically possible, and the variance would be
applicable to a specific treatment process conducted at Bethlehem
Apparatus and disposal location at USE's TSD in Beatty, Nevada.\2\
Specifically, as the USE petition demonstrates, the required treatment
standard of placing elemental mercury into commerce for reuse after
RMERC is inappropriate because the small market demand for elemental
mercury is greatly exceeded by the supply of elemental mercury
recovered from D009 and U151 hazardous wastes and from Bevill wastes
generated by the U.S. gold mining industry (<a href="https://www.epa.gov/system/files/documents/2023-12/2023-mercury-inventory-report_final.pdf">https://www.epa.gov/system/files/documents/2023-12/2023-mercury-inventory-report_final.pdf</a>) and
the resulting stockpiled elemental mercury poses an ongoing potential
hazard to human health and the environment. Approval of the petition,
with conditions, will allow for the site-specific treatment and land
disposal of elemental mercury in a manner that minimizes threats to
human health and the environment posed by the waste.
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\2\ According to 42 CFR 268.44(h)(2), a petitioner may obtain a
variance from an applicable treatment standard if it is
inappropriate to require the waste to be treated to the level
specified in the treatment standard or by the method specified as
the treatment standard, even though such treatment is technically
possible. To show that this is the case, as applicable here, the
petitioner must demonstrate that treatment to the specified level or
by the specified method is technically inappropriate (for example,
resulting in combustion of large amounts of mildly contaminated
environmental media). Section 268.44(m) further requires the
petitioner to demonstrate that compliance with the variance is
sufficient to minimize threats to human health and the environment
posed by land disposal of the waste.
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III. Background

A. Mercury in the Environment

Mercury is a naturally occurring element. It enters the environment
from natural sources (such as volcanoes) and human activities (such as
industrial combustion and gold mining). Elemental mercury is an element
that has not reacted with another substance. When mercury reacts with
another substance, it forms a compound. Elemental mercury and mercury
compounds have their own unique chemical properties, physical
properties, and chemical structures. Once released into the
environment, inorganic forms of mercury may be converted to the mercury
compound methylmercury, which is the main form of organic mercury found
in the environment. Methylmercury has been shown to be a developmental
toxicant, with exposure causing subtle to severe neurological effects
at very low levels of exposure, especially to fetuses and young
children. For more information, visit the EPA website at <a href="https://www.epa.gov/mercury/health-effects-exposures-mercury#methyl">https://www.epa.gov/mercury/health-effects-exposures-mercury#methyl</a>.
The EPA's Mercury Study Report to Congress underscores the
extensive research the Agency has conducted on mercury leading up to
the 2008 Mercury Export Ban Act (MEBA) discussed later in this proposed
approval. See Mercury Study Report to Congress, Volumes I-VIII, EPA-
452/R-97-003, December 1997. In a separate action, the EPA identified
mercury as one of the ``53 persistent, bioaccumulative, and toxic
chemicals and chemical categories which may be found in hazardous

[[Page 5402]]

wastes regulated under RCRA.'' See 63 FR 60332, November 9, 1998. A May
28, 1999, Advanced Notice of Proposed Rulemaking (ANPRM) (64 FR 28949)
addressed a small but critical aspect of the broader mercury
contamination issue, specifically focusing on the treatment and
disposal of mercury-bearing hazardous wastes. Disposal of mercury is
challenging because, if not properly treated before disposal, it can be
released into the environment where it can react and be converted to
methylmercury.

B. U.S. Laws and Treaties Affecting International Supply and Trade of
Elemental Mercury and Mercury Compounds

Beginning in 2013, MEBA prohibited exports of elemental mercury
(with very limited exceptions), provided for long-term management and
storage of elemental mercury in the U.S. by the Department of Energy
(DOE), and prevented the sale, distribution, or transfer of elemental
mercury held by U.S. federal agencies. See Mercury Export Ban Act of
2008, Public Law 110-414, as amended by the Frank R. Lautenberg
Chemical Safety for the 21st Century Act, Public Law 114-182. In 2016,
the Frank R. Lautenberg Chemical Safety for the 21st Century Act
(Lautenberg Act) expanded the export ban to include five mercury
compounds: mercury (I) chloride or calomel; mercury (II) oxide; mercury
(II) sulfate; mercury (II) nitrate; and cinnabar or mercury sulfide.
That ban took effect on January 1, 2020. MEBA does not affect RCRA or
RCRA regulations, with the exception that elemental mercury stored at
the DOE facility, or elemental mercury that is destined for the DOE
facility and meets other requirements outlined in MEBA as amended in
2016, is not subject to the RCRA storage prohibition of 3004(j) of the
Solid Waste Disposal Act. See 42 U.S.C. 6939f(g).
The United States is a Party to the Minamata Convention on Mercury
(Convention), which entered into force on August 16, 2017. The
Convention includes several provisions to reduce exposure to mercury,
including a prohibition on new mercury mines and the phase-out of
existing ones and the phase-out and phase-down of mercury use in
specified products and processes. Some articles of the Convention
pertain only to elemental mercury, while others apply to mercury
compounds, as well. Legal demand for elemental mercury continues to
fall globally.

C. Industries Generating Mercury Wastes

The Inventory of Mercury Supply, Use, and Trade in the United
States 2023 Report (visit EPA website at <a href="https://www.epa.gov/system/files/documents/2023-12/2023-mercury-inventory-report_final.pdf">https://www.epa.gov/system/files/documents/2023-12/2023-mercury-inventory-report_final.pdf</a>) shows
how industrial use and reuse of mercury in the United States has been
declining for decades, with significant changes in production and
consumption patterns. Mercury has not been domestically produced from
ore since 1990, when the last U.S. mine closed. However, mercury wastes
continue to be generated as a byproduct from gold ore mining and
secondary production processes. Nearly all mercury used in the U.S. now
comes from secondary sources, which include soil cleanup and
remediation wastes, spent batteries, chlor-alkali plants during
decommissioning of electrolytic cells, mercury vapor and fluorescent
lamps, dental amalgams, electrical apparatus, and measuring
instruments. Secondary producers typically employ high-temperature
roasting and retorting to reclaim mercury from these waste materials,
followed by distillation to purify contaminated liquid mercury metal.
Pursuant to MEBA, the DOE was directed to designate and operate a
facility or facilities for the long-term management and storage of
elemental mercury generated within the United States. See 42 U.S.C.
6939f(a). DOE issued a record of decision on December 2, 2024,
selecting Waste Control Specialists, LLC (WCS) near Andrews, Texas (89
FR 95189) as the designated facility, but as of the date of this
proposed action, WCS has not yet started accepting elemental mercury
under MEBA.

D. Existing Mercury Treatment Standards

The EPA delineated two treatment subcategories for D009 and U151
mercury-containing hazardous waste in 40 CFR 268.40. The high mercury
subcategory, which is relevant to this action, includes wastes with a
total mercury concentration greater than or equal to 260 mg/kg, and the
low mercury subcategory includes wastes with a total mercury
concentration less than 260 mg/kg. Low mercury wastes are not mandated
to follow a specific treatment technology but must achieve a numerical
treatment standard of either 0.20 mg/L TCLP for nonwastewater residues
from retorting or roasting or 0.025 mg/L TCLP for other nonwastewater
low mercury wastes. For treatment of high mercury wastes, EPA selected
the Best Demonstrated Available Technology (BDAT) as incineration
(IMERC) if organics are present within the high mercury wastestream and
roasting or retorting (RMERC) when organics are not present, and both
these treatment options involve separating elemental mercury from the
rest of the waste. See 40 CFR 268.42(a), table 1. This elemental
mercury reclaimed from high mercury waste cannot be land disposed as it
was intended to be placed into commerce. RMERC residues must meet a
numerical treatment standard of 0.20 mg/L prior to land disposal, as
measured by the toxicity characteristic leaching procedure (TCLP),
while all other nonwastewaters that exhibit or are expected to exhibit
the characteristic of toxicity for mercury that are in the low mercury
subcategory and are not residues from RMERC, must meet a more stringent
standard of 0.025 mg/L TCLP. Elemental mercury contaminated with
radioactive materials was never considered appropriate for placement
into commerce and so has an existing land disposal treatment standard
of amalgamation. See 40 CFR 268.42.
On January 29, 2003, EPA published a Notice of Data Availability
(68 FR 4482) (the Notice) after reviewing studies conducted on the
treatment of high mercury wastes. The EPA wanted to evaluate options to
propose treatment and disposal alternatives to the existing LDR
treatment standards of IMERC or RMERC. The Notice concluded that no
technology demonstrated adequate stability across the plausible range
of pH conditions found in landfills to ensure that mercury would not
leach from the treated high mercury hazardous waste if land disposed.
Additionally, other factors, such as leachate salinity, can
significantly affect the solubility of mercury from treated wastes. As
a result, the Agency concluded that reclamation of elemental mercury
from D009 and U151 hazardous wastes for placement into commerce
remained the most reliable approach for managing high mercury waste in
a manner that is protective of human health and the environment. The
EPA also stated that site-specific environmental conditions may be
addressed in a petition for a site-specific variance from the
applicable treatment standard that prohibits land disposal of elemental
mercury.
Currently there are international treatment and disposal options
for the land disposal of elemental mercury that appear to address the
concerns with land disposal that the Agency identified. Because of the
international disposal options, some domestic companies, such as
Bethlehem

[[Page 5403]]

Apparatus, do treat elemental mercury for export and disposal.
On January 16, 2025, DOE published a request for information
regarding treatment and disposal of elemental mercury (90 FR 4728)
indicating ongoing need and interest for treatment and disposal
alternatives.

E. Why is a treatability variance necessary for elemental mercury
extracted from high mercury wastes?

The EPA continues to find that recovering elemental mercury from
high concentration mercury waste is appropriate because there are no
identified treatment and disposal options for such wastes in the U.S.
prior to incineration or retort/recovery that ensure adequate
protection of human health and the environment. However, the EPA also
finds that it is inappropriate to leave placement into commerce of
elemental mercury the only final disposal option because there is no
commercial market for elemental mercury. The Agency therefore concludes
that a treatment and land disposal option is appropriate if a petition
can demonstrate that the alternative treatment standard will
substantially reduce the likelihood of migration of hazardous
constituents from the waste so that short-term and long-term threats to
human health and the environment are minimized. Specific to mercury, as
noted in the 2003 Notice, the petition for a variance must demonstrate
that the treatment is effective under planned disposal conditions for
the expected pH range for the disposal site and it must describe the
specifics and likely effectiveness of the stabilization treatment to be
used, among other things.

IV. Description of the Treatment and Disposal Approach in the Petition

On June 30, 2021, USE submitted a petition for a Determination of
Equivalent Treatment under 40 CFR 268.42(b) to treat and dispose of
elemental mercury reclaimed from the retort of D009 and U151 high
mercury wastes. In response to EPA requests following the original June
2021, submission, on September 22, 2025, USE provided supplemental
information and a revised petition, including a separate request for
the Agency to evaluate the treatment process as a site-specific
treatability variance pursuant to 40 CFR 268.44. Additional
communication with USE led to the Agency proposing to include Bevill-
exempt wastes from U.S. gold mining operations to the petition. The
original and revised petitions and associated responses to Agency
information requests (together referred to as ``the petition'') can be
found in the docket (EPA-HQ-OLEM-2025-2038).

A. Treatment Process

The petition includes the conclusions of a study of a process for
treating and stabilizing elemental mercury reclaimed from high mercury
wastes that will minimize the risk of mercury release from the treated
waste and allow for land disposal. USE has an existing agreement with
Bethlehem Apparatus to perform the treatment portion of this process.
Bethlehem Apparatus is permitted to treat/recycle mercury-bearing
wastes through distillation to generate elemental mercury in the manner
provided in their permits by the Commonwealth of Pennsylvania pursuant
to its approved RCRA Subtitle C program. Visit Pennsylvania's DEP
website to locate Bethlehem Apparatus's permits at <a href="https://www.ahs.dep.pa.gov/eFACTSWeb/searchResults_singleAuth.aspx?AuthID=16767">https://www.ahs.dep.pa.gov/eFACTSWeb/searchResults_singleAuth.aspx?AuthID=16767</a>. Bethlehem Apparatus also
exports such treated elemental mercury for disposal. The Bethlehem
Apparatus process post-RMERC includes: (1) conversion of distilled and
retorted high-purity elemental mercury into a stable form of mercury
sulfide (HgS) powder by reaction without significant excess sulfur
through a patented proprietary process (U.S. Patent Nos. 7,691,361 and
8,501,107); (2) blending the HgS powder with melted linear low-density
polyethylene (LLDPE) under a proprietary process with defined
parameters under vacuum; and (3) extruding the LLDPE-HgS blend as a
monolith (hereafter referred to as ``HgS waste'') directly into
Department of Transportation (DOT)-rated nonreactive container (such as
high density polyethylene (HDPE)) closed-head drums). Bethlehem
Apparatus is required to conduct all portions of the treatment in
compliance with its air and RCRA permits issued by Pennsylvania. All
containers used to transport the HgS waste offsite from Bethlehem
Apparatus to USE's Beatty, Nevada facility must meet all applicable DOT
requirements under 49 CFR subchapter C.

B. Disposal Environment

For final disposal, USE must construct a designated HgS hazardous
waste (Subtitle C) monofill at its Beatty, Nevada facility, in
compliance with its RCRA permit, where leachate generation is expected
to be minimal due to its location in an arid environment.
Controlling variable environmental conditions that may influence
mercury leaching from HgS waste is a critical part of the petition for
a variance. USE's proposed monofill must only accept HgS waste treated
by the process described in this proposal and USE's September 22, 2025,
petition, subject to the conditions summarized in section VI.,
Conditions for Treatment and Disposal of HgS Wastes, of this proposal.
The proposed monofill disposal site is located within an existing RCRA
Subtitle C permitted facility in an arid environment in Beatty, Nevada,
with an average annual rainfall of less than seven (7) inches per year.
This location limits the potential impacts of rainwater to the disposal
site by lowering the potential for leachate generation. Disposal in a
segregated monofill reduces potential infiltration from other portions
of the facility and the introduction of other contaminants or minerals
from rainwater that may negatively influence mercury leachability. For
these reasons, the EPA has determined that the proposed monofill
location will minimize the potential for mercury migration or leaching
from the treated waste. Additionally, the nearest residence is located
approximately eleven (11) miles from the site, a safeguard against
potential human interference or interaction with the disposal site.
The Nevada Department of Environmental Protection (NDEP) regulates
hazardous waste pursuant to Nevada Administrative Code (NAC) and the
Nevada Revised Statutes (NRS), as a State authorized to implement a
hazardous waste program under the RCRA. As such, prior to construction
of the monofill and acceptance/disposal of any HgS waste at the Beatty,
Nevada facility, USE must obtain all necessary permits and permit
modifications from NDEP.
The proposed monofill must meet, at a minimum, all Subtitle C
standards and requirements imposed by NDEP. The approval of this
variance application does not limit the delegated RCRA authority of
NDEP to establish design and permitting conditions. Nothing in this
document authorizes the disposal of HgS waste from the process
described in this proposed approval at any portion of the facility
other than the designated monofill that must be approved and permitted
by NDEP. In addition to all applicable RCRA requirements of 40 CFR
parts 260-271 and corresponding state regulations, EPA herein requires
USE to meet those specific conditions described in section VI. below,
to retain this variance.

V. Basis for EPA's Proposed Determination To Approve

EPA evaluated both the proposed treatment and the disposal methods
for

[[Page 5404]]

reclaimed elemental mercury in USE's petition to determine whether they
will minimize threats to human health and the environment consistent
with RCRA and the EPA's statutory mandates and existing regulations. As
explained further below, the Agency's evaluation of the proposed
treatment approach agrees that the petition demonstrated that the
concentration of mercury that leached from LLDPE encapsulated HgS
monoliths is significantly lower than the Agency's most stringent
established LDR standard of 0.025 mg/L TCLP for land disposal of
mercury waste. Further, the potential for mercury leaching from LLDPE-
encapsulated HgS monoliths was evaluated before those monoliths were
encased in non-reactive containers, and therefore the potential for
mercury leaching once disposed in USE's monofill within the containers
is further reduced.
In addition, the evaluation of the proposed disposal site supports
the Agency's preliminary determination to approve the variance. The
proposed site is a monofill dedicated to disposal of HgS waste with a
separate leachate collection system that should both prevent migration
of mercury and allow for long-term evaluation of the effectiveness of
the treatment because if any mercury is detected in the monofill
leachate system, it will have a known source.
For these and other reasons discussed below, EPA is proposing to
approve a site-specific treatment variance for the land disposal of
treated elemental mercury in Beatty, Nevada, as described in the USE
petition, subject to the additional conditions set forth below in
section VI.

A. Evaluation of the Proposed Encapsulation Process

EPA undertook a study to validate LEAF analytical data results
generated by USE's contract laboratory, Eurofins, for one of the waste
forms and to ensure the results were reproducible. Additionally, EPA
performed leaching experiments on one of the LLDPE-encapsulated HgS
waste forms using backfill soil collected from USE's proposed HgS waste
monofill area to determine what effect, if any, leaching solution
composition might have on mercury mobility.
USE engaged the EPA early in the process while compiling the
original petition and remained engaged with the Agency throughout the
process of data validation and leaching confirmation. The result of
this engagement saw the final form of the treated waste replace USE's
originally proposed process that extruded LLDPE-HgS into pellets and
then placed the pellets into a closed-head HDPE drum. A summary of the
results of both the EPA's validation study and USE's confirmatory
sampling are presented below. Detailed methods and results of the EPA
verification study, which includes data sets from USE's contract
laboratory are in the docket for this action (EPA-HQ-OLEM-2025-2038)
within the document titled Evaluation of the Leaching Potential of
Mercury from Polyethylene-Encapsulated Mercury Sulfide Material for
Disposal.
The EPA determined that it is necessary for the HgS waste to be
disposed of in a Subtitle C monofill and be subject to the most
stringent existing concentration-based LDR standard of 0.025 mg/L TCLP
for mercury-containing nonwastewater. Further, USE is required to
verify, at least quarterly as specified in section VI. below, that
mercury leaching will not exceed 0.025 mg/L using the SW-846 LEAF
method 1315 with modifications appropriate for mercury to estimate flux
from the HgS waste and, assuming a 20-to-1 liquid-to-solid ratio and 18
hour leaching timeframe, to compare directly to the 0.025 mg/L LDR
standard based on the traditional Toxicity Characteristic Leaching
Procedure (TCLP) (U.S. EPA SW-846, EPA Method 1311). Refer to EPA
document ``Summary Document'' in the docket for details.
1. Leaching Testing Method Selection and Data Verification Process
Leaching tests are the primary and most widely used indicator for
evaluating the contaminant retention capacity of a solid matrix.
Because this proposed alternative treatment process would result in
much higher concentrations of mercury potentially being land disposed
than currently exists, and because of the toxic nature of mercury, EPA
required USE to perform a range of aqueous leaching tests on HgS waste
using LEAF methods 1313, 1314 and 1315 in addition to TCLP (method
1311) as part of the petition review process. These additional leaching
tests included evaluation of pH-dependence of mercury leaching and
evaluating dynamics of leaching behavior from HgS powder and LLDPE-
encapsulated HgS waste forms.
The LEAF methods provide a more robust and accurate assessment of
contaminant leaching behavior than TCLP because LEAF considers a range
of environmental conditions and waste form properties and thereby
facilitates management scenario-specific evaluation of potential
constituent leaching. In contrast, TCLP was developed only to evaluate
co-disposal with municipal solid waste as a plausible mis-management
scenario, which is a disposal scenario not being considered for the HgS
waste. See 55 FR 11798, March 29, 1990, for more information on the
TCLP, noting that TCLP was originally developed to assess the
plausible, worst case mismanagement scenario for evaluating industrial
waste co-disposed in a municipal solid waste landfill. Although more
extreme pH conditions have been observed in landfills, a historic
compilation of landfill data indicates that approximately 95 percent of
all hazardous waste landfills fall within the 2 to 12 pH range, with
more than 90 percent being less than pH 10. See 65 FR 37945, June 19,
2000. In addition to meeting the 0.025 mg/L LDR standard by TCLP, EPA
determined that quarterly verifications would also be required for the
first two years and annually thereafter that diffusion of mercury from
the LLDPE-encapsulated HgS waste form would continue to meet the LDR
standard of 0.025 mg/L using LEAF method 1315 with modifications
described in the document titled Evaluation of the Leaching Potential
of Mercury from Polyethylene-Encapsulated Mercury Sulfide Material for
Disposal in the docket. This additional testing is appropriate to
ensure consistency of the integrated process for transforming elemental
mercury into water-insoluble HgS and encapsulation in LLDPE and to
ensure mercury leaching behavior continues to meet the performance
standards during evaluation of their petition for disposal in case site
conditions at USE's monofill fluctuate in future decades.
Leaching experiments were conducted on three waste forms of HgS for
a total of eight (8) experiments to compare the ``worst case scenario''
leaching potential of unencapsulated HgS powder with the leaching
potential of two forms of LLDPE-encapsulated HgS.
2. Summary of Key Findings From Leaching Experiments on HgS Waste Forms
Below is a summary of the methods and results of all experiments
performed in the document titled Summary of HgS-Leaching Experiments
Conducted by USE and EPA (``Summary Document'') located in the docket
for this proposal. The following key findings are excerpts from that
document for tests on three different states of HgS--unencapsulated
powder, LLDPE encapsulated pellets, and LLDPE encapsulated monoliths.

[[Page 5405]]

a. Waste Form 1--Unencapsulated HgS Powder
HgS powder is elemental mercury that has been retorted and
redistilled and then converted to HgS in a batch process by introducing
it into a computer-controlled mixing oven and heating with a slight
stoichiometric excess of elemental sulfur, depositing solid,
crystallized HgS on the surface of the drum inside the oven that was
scraped and collected as a fine powder.
USE conducted aqueous leaching experiments on Waste Form 1 that
included TCLP testing by method 1311 and column leaching tests by LEAF
Method 1314, both of which were run on four (4) samples of this waste
form derived from three (3) separate batches. Half of the TCLP results
exceeded the 0.025 mg/L LDR standard, with a maximum concentration of
0.045 mg/L. The maximum cumulative release of mercury per unit mass of
the waste across all method 1314 column tests and integrated over all
leaching intervals up to a liquid-to-solid ratio of 10 L/kg was 0.24
mg/kg. This release corresponded to a hypothetical mercury
concentration of 0.024 mg/L at the 20 L/kg liquid-to-solid (L/S) ratio
used for TCLP (see supporting document for details), which was just
below the LDR standard. Mercury concentrations also exceeded 0.025 mg/L
at one or more leaching intervals in two of the four column tests.
Based on the limited aqueous leaching data provided for this waste
form, it would be unlikely to consistently meet the LDR standard of
0.025 mg/L for mercury by TCLP.
b. Waste Form 2--LLDPE-Encapsulated HgS Pellets (Pellets)
HgS pellets are HgS powder that is mixed with melted LLDPE
encapsulating reagent in approximately a 1:6 ratio, after which it is
extruded through a dye and cut into roughly spherical pellets
approximately 3-4 mm in diameter.
USE conducted TCLP testing using method 1311 on 20 samples from
four (4) separately produced batches of this waste form. None of the
tested samples exceeded the 0.025 mg/L LDR standard for this waste
form, and only one of the 20 results exceeded half of the LDR standard.
USE and EPA also conducted 17 column tests using method 1314 on four
(4) separately produced batches of this waste form. The maximum mercury
release across all column tests and integrated across all leaching
intervals up to a L/S ratio of 10 L/kg was 0.041 mg/kg. This release
corresponded to a hypothetical mercury concentration of 0.0041 mg/L at
the 20 L/kg L/S ratio used for TCLP, which was less than 20% of the LDR
standard. The mercury concentration only exceeded the 0.025 mg/L LDR
standard in one leaching interval in one (1) column test (one (1)
result of a total of 152 aqueous column eluate samples tested across
these column experiments). Collectively, these leaching experiments
demonstrated that this waste form would be likely to consistently meet
the 0.025 mg/L LDR standard for mercury by TCLP.
USE and EPA conducted additional pH-dependent batch leaching tests
by Method 1313 on this waste form and observed that aqueous leaching of
mercury increased at alkaline pH (pH 7 < pH 9 < pH 10.5 < pH 12).
Average mercury concentrations were 0.003-0.008 mg/L at pH 3-5 (n=4),
0.0014 mg/L at pH 7 (n=10), 0.012 mg/L at pH 9 (n=10), 0.027 mg/L at pH
10.5 (n=10), and 0.051 mg/L at pH 12 (n=10). These results indicated
that the mildly acidic pH used for TCLP testing would likely not
represent the worst-case disposal scenario for this waste form. For
reference, USE reported aqueous pH in the range of 8.3-9.4 for water in
contact with backfill soil excavated from the proposed disposal site.
EPA conducted additional column tests by Method 1314 on this waste
form in the presence of backfill soil from the proposed disposal site.
The columns were configured so that the aqueous leaching solution
flowed through the backfill soil and then through the pellets. Column
experiments were conducted on three (3) separate batches of pellets,
and parallel column tests were performed contemporaneously on the same
batches of pellets with no backfill soil. None of aqueous column eluate
samples contained mercury concentrations above the laboratory's Lower
Limit of Quantitation (LLOQ) in any of the leaching intervals. The
maximum mercury release calculated assuming all values were at the LLOQ
was <0.0250 mg/kg for column tests with backfill soil vs <0.0248 mg/kg
for pellets without backfill soil. No quantifiable increase in mercury
release was observed in the column tests with backfill soil and pellets
compared to columns tests with only pellets. The hypothetical mercury
concentrations in these experiments corresponding to an L/S ratio of 20
L/kg was <0.0025 mg/L after accounting for differences in solution-to-
solid ratios in method 1314 relative to method 1311, which was an order
of magnitude below the 0.025 mg/L LDR standard for mercury by TCLP.
c. Waste Form 3--LLDPE-Encapsulated HgS Monolith (Monolith)
A HgS monolith is HgS powder that is mixed with melted LLDPE
encapsulating reagent in approximately a 1:6 ratio, extruded into a
mold and cooled to make cylindrical monoliths that were approximately
5.1 cm diameter x 10.2 cm height. USE conducted semidynamic tank
leaching tests by LEAF method 1315 on six (6) replicate monolith
samples at nine (9) leaching intervals up to 14 days each, for a total
of 63 days. The maximum cumulative release of mercury estimated across
all Method 1315 monolith tests and across all leaching intervals was
only 3% higher than when all results were below the LLOQ and the
mercury concentration in each interval was assumed to be at the
laboratory's LLOQ of 0.0002 mg/L. The upper boundary mercury flux
estimated from the 1315 tests and assuming that results below the LLOQ
of 0.0002 mg/L were at the LLOQ was 2.4*10-6
(mg)(m\2\)-1(sec)-1, or 0.21
(mg)(m\2\)-1(day)-1. For the LLDPE-encapsulated
HgS monoliths that were tested (cylinders ~10.2 cm height x 5.1 cm
diameter, with a nominal mass of 0.26 kg, volume of 0.00021 m\3\, and
surface area of 0.020 m\2\), the hypothetical mercury concentration in
an aqueous solution in contact with the monolith at an assumed 20 L/kg
L/S ratio and 18-hour leaching interval used for TCLP extraction was
0.00016 mg/L, which is more than two orders of magnitude below the
0.025 mg/L LDR standard. This hypothetical concentration would decrease
further as the size of the monolith is scaled up due to corresponding
decrease in surface area-to-volume ratio.
3. Experiment Conclusions
Overall, the USE and EPA studies \3\ characterized the release of
mercury and major ions from LLDPE-HgS pellets alone and in contact with
porewater from backfill soil and the release of mercury and major ions
from HgS monoliths. Analysis of the batch testing samples from the
pellets showed leaching of mercury throughout the varying liquid to
solid column ratios (L/S), i.e., volume of eluant per unit mass of the
solid; however, the concentration of mercury in column eluates remained
less than the LDR treatment standard of 0.025 mg/L. The

[[Page 5406]]

presence of backfill soil in the columns did not result in a
quantifiable increase in mercury release. Comparison of EPA Method 1314
results to Eurofins' results showed some variation in the concentration
of mercury in eluate throughout testing, though most data points
remained less than the comparable LDR treatment standard. The leaching
of mercury from the pellets throughout all experimentation may be
indicative of an inconsistent polyethylene encapsulation, which could
be due to swelling of the pellets, cracking the coating, variations in
polyethylene thickness during the production of the pellets, or
inconsistencies in washing of the pellets during production.
---------------------------------------------------------------------------

\3\ See USE 7/2021 petition for leaching studies of HgS powder
and LLDPE-HgS pellets. See USE 9/22/2025 petition for leaching
studies of LLDPE-HgS monoliths. EPA studies are found in Evaluation
of the Leaching Potential of Mercury from Polyethylene-Encapsulated
Mercury Sulfide Material for Disposal in the docket.
---------------------------------------------------------------------------

Imaging of the pellets through both optical microscopy and scanning
electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) also
indicated a change in the polyethylene encapsulation of the pellets,
with cracks in the polyethylene shown in the optical microscope images
of post-column testing pellets and a higher exposure of mercury
particles shown in the wet pellet images on SEM/EDS.
The monolithic form of the polyethylene HgS material showed minimal
release of mercury throughout Method 1315 testing. Overall, the initial
flux of mercury was less than 2.4E-6 mg/m\2\/sec (0.21 mg/m\2\/d), and
a maximum cumulative release less than 0.16 mg/m\2\ when assuming the
LLOQ for leaching results measured at less than the LLOQ. The monoliths
had minimal mercury release throughout testing, indicating that USE's
proposed alternative treatment process using the monolithic form is a
viable option for treatment and disposal of elemental mercury stores
under the site-specific conditions evaluated and established in this
proposed approval. Additional calculations to compare the Method 1315
cumulative release to TCLP conditions indicate that the comparative
concentration of mercury from Method 1315 results would be more than
two orders of magnitude less than the concentration of mercury set by
LDR limits. This comparison supports the viability of LLDPE HgS
monoliths as a treatment technique for elemental mercury.

B. Bases for Proposed Approval of USE' Petition for Variance

Pursuant to 40 CFR 268.44(h), the EPA is proposing to approve USE's
variance to allow for the land disposal of treated elemental mercury at
their Beatty, Nevada facility. The Agency finds that the existing
treatment standard is inappropriate because it requires that elemental
mercury recovered from retorting of D009 and U151 high mercury wastes
or Bevill exempt wastes from the U.S. gold mining industry be reentered
into commerce and prohibits land disposal, but there is no market for
elemental mercury. Instead, it is being accumulated at treatment
facilities around the country. The continued storage of elemental
mercury in its natural liquid form poses an ongoing potential hazard to
human health and the environment. See 40 CFR 268.44(h)(2)(i) requiring
a petitioner demonstrate that the specified treatment is technically
inappropriate, even though it is technically possible. The Agency
further concludes that the treatment and disposal approach proposed in
this action will minimize threats to human health and the environment
posed by land disposal. Further, the Agency finds that USE's proposed
approach is more effective at minimizing threats to human health and
the environment than the existing LDR standard requiring elemental
mercury be reentered into commerce because there is no market for it,
and it is being stored indefinitely throughout the country.
As explained above, the existing LDR regulations require non-
organic containing high mercury waste be treated via RMERC to recover
elemental mercury so that the potential leachable concentration of
mercury in the RMERC residue wastes, considered low mercury wastes, do
not exceed regulatory leachate levels of 0.20 mg/L, as measured by the
toxicity characteristic leaching procedure (TCLP). While subject to
treatment to prevent leaching of mercury, low mercury wastes may be
land disposed in a designated Subtitle C landfill. However, the
regulations require the recovered elemental mercury to be reentered
into commerce because at the time the regulations were established
there was both a domestic and an international market for elemental
mercury. Domestic demand for mercury fell by more than 75% from 1988
(1503 metric tons) to 1997 (346 metric tons), because environmental
concerns led to both voluntary and regulatory reductions in the use of
elemental mercury. For example, mercury was eliminated as a paint
additive and the use of mercury in batteries was reduced. Other factors
contributing to this decline in the domestic market include the
military phase-out of mercury fulminate as a primer in explosives and
the decreasing number of chlor-alkali facilities using the mercury cell
method for chlorine production. With respect to the international
market, MEBA and the Lautenberg Acts have virtually eliminated the
international market for elemental mercury recovered from high mercury
wastes. For these reasons, the EPA finds that the existing requirement
to place elemental mercury into the market is technically inappropriate
and that the proposed treatment alternative is appropriate, allowing
for the land disposal of elemental mercury in a manner that is
protective of human health and the environment.
The EPA also finds that the disposal environment in Beatty, Nevada
is appropriate for the long-term disposal of HgS waste as treated via
existing agreement between USE and Bethlehem Apparatus. The disposal
location is critical because environmental factors can significantly
affect the solubility of mercury from treated wastes and the leaching
studies the EPA performed considered the proposed disposal environment.
USE must dispose of HgS wastes in a monofill located in an arid
environment to limit potential interaction of differing wastes and
control contaminant interactions. The monofill will also have an
independent leachate collection system to further prevent interaction
or migration of waste from the unit.
For all these reasons, EPA finds that the conversion of elemental
mercury from RMERC to HgS powder and subsequent blending of the HgS
powder with LLDPE and extrusion in monolithic form into non-reactive
containers, under the terms of the proposed variance, will minimize
threats to human health and the environment posed by land disposal of
elemental mercury waste. The EPA finds that the disposal site location
and environmental conditions (i.e., in a monofill with an observed pH
between 8.3 and 9.4) further support a conclusion that approval of this
variance with conditions listed in section VI., below, will minimize
the threats to human health and the environment from land disposal of
treated elemental mercury. Moreover, the EPA concludes that the studies
confirm that the method of proposed treatment of elemental mercury
reduce its volatility and solubility/leachability and that it is thus
appropriate for long-term management in the proposed disposal
environment.\4\ To ensure proper treatment and disposal continues after
the variance is issued, the EPA is

[[Page 5407]]

requiring specific measures that must be put into place to prevent the
treated HgS waste from being degraded after treatment, during
transportation, and after disposal in the monofill.
---------------------------------------------------------------------------

\4\ In the 2003 Notice of Data Availability (68 FR 4482) the EPA
specified these demonstrations for treated waste that petitions
related to high mercury waste must meet above and beyond a standard
treatability variance.
---------------------------------------------------------------------------

For all these reasons, pursuant to 40 CFR 268.44(h), the EPA is
proposing to approve a site-specific variance for elemental mercury
recovered from high mercury wastes as treated via existing agreement
between USE and Bethlehem Apparatus, to be disposed of in a monofill in
USE's Beatty, Nevada Subtitle C landfill, subject to the conditions in
section VI., below.

VI. Conditions for Treatment and Disposal of HgS Wastes

In addition to the alternative treatment protocols identified in
section IV. of this proposed approval and further detailed in USE's
September 22, 2025, petition, USE must adhere to the following
conditions.
1. Prior to construction of the monofill and acceptance/disposal of
any HgS waste at the Beatty, Nevada facility, USE must obtain all
necessary federal, state and local permits.
2. For HgS waste, USE must meet the concentration based LDR
standard of 0.025 mg/L using TCLP, Method 1311; however, USE must also
conduct periodic confirmation testing on two (2) batches at least
quarterly for the first two (2) years and annually on two (2) batches
thereafter of the HgS waste using the most recently approved revision
of LEAF Method 1315 with modifications appropriate for mercury (See EPA
``Summary Document'' in the docket for details) to confirm continued
compliance with the concentration-based LDR standard of 0.025 mg/L.
Additional confirmation testing may be established by NDEP as part of
the permitting process.
3. To confirm that excess mercury is not present in the HgS powder
prior to blending with LLDPE, for at least one (1) of every twenty (20)
batches of HgS powder destined to be blended with LLDPE and disposed at
the Beatty, Nevada facility, USE must request that Bethlehem Apparatus
provide analytical data to the EPA.
4. HgS waste must be disposed within a permitted Subtitle C
monofill at the USE Beatty, Nevada TSD facility.
5. Disposal of HgS waste at the Beatty, Nevada monofill is
predicated on compliance with USE's Subtitle C permit conditions for
the treated HgS waste.
6. The mercury waste management facilities, including any waste
treatment, storage or disposal areas, must be designed and constructed
such that the containment system, leachate management system,
stormwater collection and control system, and future cover and closure
systems are independent of other environmental control systems for the
facility. The stormwater control systems for the mercury waste
management facilities must not allow stormwater run-off to or run-on
from other waste management units and must be designed to contain at
least the water volume resulting from a 24-hour, 100-year event. This
condition must be met during the life of the facility for operation,
closure, and post-closure periods.
7. Leachate from other portions of the facility must not be used
for dust suppression at the monofill. Leachate from the monofill itself
may only be used for dust suppression if the leachate collected from
the monofill is analyzed and does not contain any hazardous
constituents.
8. Unless a Future Amendment to this variance is approved as
described in section VII., below, USE can only accept HgS waste as
treated via existing agreement between USE and Bethlehem Apparatus.

VII. Future Amendments to This Variance

Prior to the acceptance of HgS powder or HgS waste at the Beatty,
NV facility from any facility other than Bethlehem Apparatus's
Hellertown, Pennsylvania location, USE must submit a request for a
modification of this variance through a revised petition submitted
pursuant to 40 CFR 268.44 for approval by the EPA. To ensure such a
process change does not alter the performance of the treatment process
for HgS waste, the following steps are required for the Agency to
determine that the process and treatment residuals are equivalent to
those analyzed for this variance.
A. If USE proposes to use an alternate vendor for conversion of
elemental mercury to HgS powder that will then be blended into LLDPE
and extruded into a monolith, USE must:
1. Ensure any alternate vendor has secured all necessary permits
for such treatment processes from state and federal regulators.
2. Demonstrate and receive approval from EPA that the conversion
process is equivalent to the Bethlehem Apparatus process. The
demonstration must detail equivalency for the following process
controls: type of equipment used, conversion temperature, color of the
HgS powder, type and quantity of sulfur added for reaction completion
without significant excess sulfur, external environmental conditions at
the time of conversion (humidity and temperature), control of mercury
losses through volatilization and residual concentrations of other
mercury species. If any process controls differ from the Bethlehem
Apparatus process, USE must submit such revisions to EPA for approval
and request a technical meeting to discuss such revisions with the
Agency prior to receiving HgS waste from the alternate vendor.
3. Provide third-party analysis from at least five (5) samples of
HgS powder from different batches to the EPA. The analysis must
demonstrate that leaching does not exceed 0.025mg/L using TCLP and EPA
Method 1315 with modifications appropriate for mercury.
B. If USE proposes to move the LLDPE-HgS blending and extrusion
process from Bethlehem Apparatus to its Beatty, NV facility, USE must:
1. Secure all necessary permits for such treatment processes from
state and federal regulators.
2. Demonstrate and receive approval from EPA that the blending and
extrusion process is equivalent to the Bethlehem Apparatus process. The
demonstration must detail equivalency for the following process
controls: type of equipment used, temperature of the blending and
extrusion process, residence time of HgS in the mixing chamber, mixing
speed, external environmental conditions at the time of blending
(humidity and temperature) and control of mercury losses thorough
volatilization. If any process controls differ from the Bethlehem
Apparatus process, USE must submit such revisions to the EPA for
approval and request a technical meeting to discuss such revisions with
the Agency prior to commencement of the treatment process.
3. Provide third-party analysis of at least three (3) samples of
the treated LLDPE-HgS monolithic waste using TCLP and EPA Method 1315
from different batches of HgS powder.

[[Page 5408]]

Table 1--Proposed Modification to 40 CFR 268.44(o) for the High Mercury Waste Treatment Petition
--------------------------------------------------------------------------------------------------------------------------------------------------------
Wastewaters Nonwastewaters
Regulated -----------------------------------------------------------------
Facility name and address Waste code See also hazardous Concentration (mg/ Concentration (mg/
constituent L) Notes kg) Notes
--------------------------------------------------------------------------------------------------------------------------------------------------------
Wastes Excluded from the Treatment Standards Under Sec. 268.40
--------------------------------------------------------------------------------------------------------------------------------------------------------
US Ecology Nevada, Inc. Beatty, D009, U151 \21\... NA........... Mercury........... NA............... NA.......... 0.025 mg/L TCLP.. (\22\ \23\)
Nevada.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\21\ The waste codes included in this column are only for those mercury wastes identified as the high mercury subcategory in 268.40.
\22\ This site-specific treatment standard applies only to elemental mercury resulting from RMERC of D009 or U151 high mercury subcategory wastes
containing greater than or equal to 260 mg/kg mercury treated via the approved alternative treatment method described in EPA-HQ-OLEM-2025-2038. This
alternative treatment method converts elemental mercury post-RMERC to mercury sulfide powder and blends the mercury sulfide powder with linear low-
density polyethylene and extrudes the mixture as a monolithic block directly into a nonreactive container.
\23\ Disposal of elemental mercury resulting from RMERC of D009 or U151 wastes that have complied with the alternative treatment standards identified in
note 22 must be disposed within a permitted Subtitle C monofill at the US Ecology Beatty, Nevada facility. The monofill must be hydraulically
segregated from other disposal units at the facility. Leachate must not be used for dust suppression at the monofill, including leachate from the
monofill itself. This treatment variance does not relieve US Ecology of its responsibilities in the management of hazardous waste under 40 CFR parts
260 through 271. This treatment variance is conditioned on US Ecology's complying with section VI. Conditions for Treatment and Disposal of HgS Wastes
detailed in EPA-HQ-OLEM-2025-2038.

VIII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review

This action is not a significant regulatory action and was
therefore not submitted to the Office of Management and Budget (OMB)
for review.

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

This action is expected to be an Executive Order 14192 deregulatory
action. This proposed rule is expected to provide burden reduction by
replacing an unachievable LDR standard that led to the requirement for
indefinite storage of high concentration mercury wastes by DOE. The
proposed site-specific LDR standard would allow for the treatment and
disposal of high concentration mercury wastes.

John W. Busterud,
Assistant Administrator, Office of Land and Emergency Management.
[FR Doc. 2026-02346 Filed 2-5-26; 8:45 am]
BILLING CODE 6560-50-P

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