Rule2026-11432
Air Plan Approval; Minnesota; Revision to Taconite Federal Implementation Plan
Primary source
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Published
June 8, 2026
Effective
July 8, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The U.S. Environmental Protection Agency (EPA) is revising the Original 2013 Federal Implementation Plan (FIP) by finalizing nitrogen oxide (NO<INF>X</INF>) emission limits for the indurating furnace at United States Steel's (U.S. Steel) Keetac taconite facility (Keetac) in Keewatin, Minnesota to satisfy the requirement for best available retrofit technology (BART) at taconite facilities. The EPA is finalizing the following NO<INF>X</INF> BART emission limits for the Keetac Grate Kiln indurating furnace, with compliance to be determined on a rolling 720-hour average: 3.4 pounds (lbs) of NO<INF>X</INF> per million British Thermal Unit (MMBtu) when firing exclusively natural gas, which will become enforceable beginning three years after promulgation of a final rule; and 2.0 lbs NO<INF>X</INF>/MMBtu when firing any fuel or combination of fuels other than exclusively natural gas, which will become enforceable five years after promulgation of a final rule, unless before that date the EPA promulgates a modified limit. The final rule allows Keetac, within a period of 52 months from the effective date of the final rule, the option to seek a potential adjustment of the cofiring emission limit, not to exceed 2.5 lbs NO<INF>X</INF>/MMBtu as a 720-hour rolling average, based on collection of continuous emission monitoring system (CEMS) data after installation of the NO<INF>X</INF> reduction technology.
Full Text
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<title>Federal Register, Volume 91 Issue 109 (Monday, June 8, 2026)</title>
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[Federal Register Volume 91, Number 109 (Monday, June 8, 2026)]
[Rules and Regulations]
[Pages 34574-34582]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-11432]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R05-OAR-2024-2016; FRL-12599-02-R5]
Air Plan Approval; Minnesota; Revision to Taconite Federal
Implementation Plan
AGENCY: Environmental Protection Agency (EPA).
[[Page 34575]]
ACTION: Final rule.
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SUMMARY: The U.S. Environmental Protection Agency (EPA) is revising the
Original 2013 Federal Implementation Plan (FIP) by finalizing nitrogen
oxide (NO<INF>X</INF>) emission limits for the indurating furnace at
United States Steel's (U.S. Steel) Keetac taconite facility (Keetac) in
Keewatin, Minnesota to satisfy the requirement for best available
retrofit technology (BART) at taconite facilities. The EPA is
finalizing the following NO<INF>X</INF> BART emission limits for the
Keetac Grate Kiln indurating furnace, with compliance to be determined
on a rolling 720-hour average: 3.4 pounds (lbs) of NO<INF>X</INF> per
million British Thermal Unit (MMBtu) when firing exclusively natural
gas, which will become enforceable beginning three years after
promulgation of a final rule; and 2.0 lbs NO<INF>X</INF>/MMBtu when
firing any fuel or combination of fuels other than exclusively natural
gas, which will become enforceable five years after promulgation of a
final rule, unless before that date the EPA promulgates a modified
limit. The final rule allows Keetac, within a period of 52 months from
the effective date of the final rule, the option to seek a potential
adjustment of the cofiring emission limit, not to exceed 2.5 lbs
NO<INF>X</INF>/MMBtu as a 720-hour rolling average, based on collection
of continuous emission monitoring system (CEMS) data after installation
of the NO<INF>X</INF> reduction technology.
DATES: This final rule is effective on July 8, 2026.
ADDRESSES: The EPA has established a docket for this action under
Docket ID No. EPA-R05-OAR-2024-0216. All documents in the docket are
listed on the <a href="https://www.regulations.gov">https://www.regulations.gov</a> website. Although listed in
the index, some information is not publicly available, i.e.,
Confidential Business Information (CBI), Proprietary Business
Information (PBI), or other information the disclosure of which is
restricted by statute. Certain other material, such as copyrighted
material, is not placed on the internet and will be publicly available
only in hard copy form. Publicly available docket materials are
available either through <a href="https://www.regulations.gov">https://www.regulations.gov</a> or please contact
the person identified in the FOR FURTHER INFORMATION CONTACT section
for additional information.
FOR FURTHER INFORMATION CONTACT: For information about this final rule,
contact Gina Harrison, Environmental Scientist, Air and Radiation
Division (AR18J), Environmental Protection Agency, Region 5, 77 West
Jackson Boulevard, Chicago, Illinois, 60604; telephone number (312)
353-6956; email address <a href="/cdn-cgi/l/email-protection#315950434358425e5f1f56585f50715441501f565e47"><span class="__cf_email__" data-cfemail="2e464f5c5c475d4140004947404f6e4b5e4f00494158">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Preamble acronyms and abbreviations.
Throughout this preamble, the use of ``we,'' ``us,'' or ``our'' is
intended to refer to the EPA. We use multiple acronyms and terms in
this preamble. While this list may not be exhaustive, to ease the
reading of this preamble and for reference purposes, the EPA defines
the following terms and acronyms here:
BART Best Available Retrofit Technology
CAA Clean Air Act
CEMS Continuous Emissions Monitoring System
CBI Confidential Business Information
EPA Environmental Protection Agency
FIP Federal Implementation Plan
Keetac Keetac Taconite Facility in Keewatin, Minnesota
LNB Low-NO<INF>X</INF> Burner
NESHAP National Emission Standards for Hazardous Air Pollutants
NO<INF>X</INF> Nitrogen Oxide
PBI Proprietary Business Information
PRA Paperwork Reduction Act
RFA Regulatory Flexibility Act
SCR Selective Catalytic Reduction
SIP State Implementation Plan
SO<INF>2</INF> Sulfur Dioxide
UMRA Unfunded Mandates Reform Act
U.S. Steel United States Steel
Organization of this document. The information presented in this
preamble is organized as follows:
I. Background
II. Legal Authority
III. What Action is the EPA Taking?
IV. Public Comments and Responses
V. Statutory and Executive Order Reviews
Background
On February 6, 2013, the EPA promulgated a Federal Implementation
Plan (FIP) that included NO<INF>X</INF> BART limits for indurating
furnaces at seven taconite facilities subject to BART in Minnesota and
Michigan (the Original 2013 FIP Rule).\1\ The Original 2013 FIP Rule
included NO<INF>X</INF> BART limits for indurating furnaces at two U.S.
Steel taconite facilities located in Minnesota--Keetac and Minntac. The
EPA took this action following a January 15, 2009, determination that
Minnesota and Michigan failed to timely submit regional haze SIPs.\2\
This finding triggered a CAA obligation that the EPA issue a FIP, which
the Agency did on February 6, 2013. The Original 2013 FIP Rule, among
other requirements, established NO<INF>X</INF> BART emission limits of
1.2 MMBtu when burning natural gas and 1.5 lbs NO<INF>X</INF>/MMBtu
when using any fuel other than exclusively natural gas for Keetac's
indurating furnace (along with indurating furnaces at six other
taconite facilities in Michigan and Minnesota). These emission limits
were based upon the observed performance of high stoichiometric (high-
stoich) low-NO<INF>X</INF> burners (LNBs) that were previously
installed on taconite furnaces at Minntac.
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\1\ 78 FR 8706 (February 6, 2013).
\2\ 74 FR 2392 (January 15, 2009).
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Subsequent engineering studies demonstrated that the initial LNB
design selection for Keetac, which was based on LNB operation at U.S.
Steel's Minntac facility, would be infeasible at Keetac due to several
technical factors. Further studies demonstrated that a different LNB
main burner design, in combination with low-NO<INF>X</INF> preheat
burners, would be the most effective LNB design for Keetac in that the
design represents the highest technically feasible emission reductions
for this facility based on those studies.
On April 24, 2025, the EPA proposed to modify the NO<INF>X</INF>
BART emission limits for the indurating furnace at Keetac to reflect
the degree of reduction achievable based on operations and parameters
specific to the Keetac facility (the 2025 Proposed Rule).\3\
Specifically, the EPA proposed to approve the following NO<INF>X</INF>
BART emission limits for the Keetac Grate Kiln indurating furnace, with
compliance to be determined on a rolling 720-hour average: (1) 3.4 lbs
NO<INF>X</INF>/MMBtu when firing exclusively natural gas, which will
become enforceable beginning three years after promulgation of a final
rule; and (2) 2.0 lbs NO<INF>X</INF>/MMBtu when firing any fuel or
combination of fuels other than exclusively natural gas, which will
become enforceable five years after promulgation of a final rule,
unless before that date the EPA promulgates a modified limit in
accordance with the following procedure. The EPA proposed to allow
Keetac, within a period of 52 months from the effective date of the
final rule, the option to seek a potential adjustment of the cofiring
emission limit, not to exceed 2.5 lbs NO<INF>X</INF>/MMBtu as a 720-
hour rolling average, based on collection of continuous emissions
monitoring system (CEMS) data after installation of the NO<INF>X</INF>
reduction technology. Additional explanation of the CAA requirements, a
detailed analysis of how these requirements apply to taconite
facilities, and the EPA's reasons for proposing the revised limits are
provided in the 2025 Proposed Rule.
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\3\ 90 FR 17233 (April 24, 2025).
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Legal Authority
In the CAA Amendments of 1977, Congress created a program for
[[Page 34576]]
protecting visibility in the nation's national parks and wilderness
areas. Section 169A of the CAA establishes as a national goal the
``prevention of any future, and the remedying of any existing,
impairment of visibility in mandatory Class I Federal areas which
impairment results from manmade air pollution.'' Congress added section
169B to the CAA in 1990 to address regional haze issues. EPA
promulgated a rule to address regional haze on July 1, 1999 (64 FR
35714), codified at 40 CFR part 51, subpart P--Protection of Visibility
(herein after referred to as the ``Regional Haze Rule''). The Regional
Haze Rule codified and clarified the BART provisions in the CAA at 40
CFR 51.308(e) and revised the existing visibility regulations to add
provisions addressing regional haze impairment and establishing a
comprehensive visibility protection program for Class I areas.
Section 169A of the CAA directs states, or EPA if developing a
Federal Implementation Plan (FIP), to evaluate the use of retrofit
controls at certain larger, often uncontrolled, older stationary
sources to address visibility impacts from these sources. Specifically,
section 169A(b)(2)(A) of the CAA requires that implementation plans
contain such measures as may be necessary to make reasonable progress
toward the natural visibility goal, including a requirement that
certain categories of existing major stationary sources \4\ built
between 1962 and 1977 procure, install, and operate BART \5\ as
determined by EPA.
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\4\ The set of ``major stationary sources'' potentially subject
to BART is listed in CAA section 169A(g)(7) and includes ``taconite
ore processing facilities.''
\5\ 40 CFR 51.301 ``Best Available Retrofit Technology (BART).''
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Under the Regional Haze Rule, states (or in the case of a FIP, EPA)
are directed to conduct BART determinations for such ``BART-eligible''
sources that may reasonably be anticipated to cause or contribute to
any visibility impairment in a Class I area.
On July 6, 2005, (70 FR 39104), EPA published the Guidelines for
BART Determinations Under the Regional Haze Rule at appendix Y to 40
CFR part 51 (hereinafter referred to as the ``BART Guidelines''), to
assist states and EPA in determining which sources should be subject to
the BART requirements and in determining appropriate emission limits
for each source subject to BART.
The process of establishing BART emission limitations follows three
steps. First, states, or EPA if developing a FIP, must identify and
list ``BART-eligible sources.'' \6\ Once the state or EPA has
identified the BART-eligible sources, the second step is to identify
those sources that may ``emit any air pollutant which may reasonably be
anticipated to cause or contribute to any impairment of visibility'' in
a Class I area. (Under the Regional Haze Rule, a source that fits this
description is ``subject to BART.''). Third, for each source subject to
BART, the state or EPA must identify the level of control representing
BART after considering the five factors set forth in CAA section
169A(g). The BART Guidelines provide a process for making BART
determinations that states can use in implementing the BART
requirements on a source-by-source basis. See 40 CFR part 51, appendix
Y, at IV.D.\7\
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\6\ ``BART-eligible sources'' are those sources that have the
potential to emit 250 tons or more of a visibility-impairing air
pollutant, were not in operation prior to August 7, 1962, but were
in existence on August 7, 1977, and whose operations fall within one
or more of 26 specifically listed source categories. 40 CFR 51.301.
\7\ The BART Guidelines are mandatory for power plants above 750
megawatts and are considered ``useful guidance'' for other types of
sources. 70 FR 39104, 39108 (July 6, 2005).
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States, or EPA if developing a FIP, must address all visibility-
impairing pollutants emitted by a source in the BART determination
process. The most significant visibility impairing pollutants are
sulfur dioxide (SO<INF>2</INF>), NO<INF>X</INF>, and particulate matter
(PM).
A State Implementation Plan (SIP) or FIP addressing regional haze
must include source-specific BART emission limits and compliance
schedules for each source subject to BART. Once a state or EPA has made
a BART determination, the BART controls must be installed and operated
as expeditiously as practicable, but no later than five years after the
date of the final SIP or FIP. See CAA section 169A(g)(4) and 40 CFR
51.308(e)(1)(iv). In addition to what is required by the Regional Haze
Rule, general SIP requirements mandate that the SIP or FIP include all
regulatory requirements related to monitoring, recordkeeping, and
reporting for the BART controls on the source. See CAA section 110(a).
What action is the EPA taking?
The EPA is finalizing modifications to the Original 2013 FIP Rule
by changing the NO<INF>X</INF> BART emission limits for the indurating
furnace at Keetac. Specifically, the EPA is finalizing the following
NO<INF>X</INF> BART emission limits for the Keetac Grate Kiln
indurating furnace, with compliance to be determined on a rolling 720-
hour average: (1) 3.4 lbs NO<INF>X</INF>/MMBtu when firing exclusively
natural gas, which will become enforceable beginning three years after
promulgation of a final rule; and (2) 2.0 lbs NO<INF>X</INF>/MMBtu when
firing any fuel or combination of fuels other than exclusively natural
gas, which will become enforceable five years after promulgation of a
final rule, unless before that date the EPA promulgates a modified
limit. The final rule allows Keetac, within a period of 52 months from
the effective date of the final rule, the option to seek a potential
adjustment of the cofiring emission limit, not to exceed 2.5 lbs
NO<INF>X</INF>/MMBtu as a 720-hour rolling average, based on collection
of CEMS data after installation of the NO<INF>X</INF> reduction
technology.
Public Comments and Responses
The EPA received no requests for a public hearing; therefore, no
public hearing was held. The comment period on the 2025 Proposed Rule
closed on June 10, 2025. The EPA received two comments on the Keetac
proposal. One comment letter was submitted from the National Parks
Conservation Association, Coalition to Protect America's National
Parks, Minnesota Center for Environmental Advocacy, and Sierra Club
(collectively, the Conservation Groups). The second comment was
submitted anonymously. These comments are summarized and addressed
below. One additional comment was received but did not contain comments
related to the Keetac proposal.
Comment: The Conservation Groups assert that the EPA proposes to
rubber stamp Keetac's data without conducting the BART analyses
required under the CAA and Regional Haze Rule (RHR).\8\ The
Conservation Groups further assert that the EPA improperly focuses only
on the CEMS data provided by Keetac.
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\8\ The RHR was published in the Federal Register July 1, 1999
(64 FR 35714), codified at 40 CFR part 51, subpart P.
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Response: The EPA disagrees with the Conservation Groups'
assertions that the EPA proposed emission limits for Keetac without
conducting a BART analysis as set forth in the CAA and RHR. Under the
RHR, each State (or in the case of a FIP, the EPA), is directed to
conduct BART determinations for such ``BART-eligible'' sources that may
reasonably be anticipated to cause or contribute to any visibility
impairment in a Class I area.\9\
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\9\ ``BART-eligible sources'' are those sources that have the
potential to emit 250 tons or more of a visibility-impairing air
pollutant, were not in operation prior to Aug. 7, 1962, were in
existence on Aug. 7, 1977, and whose operations fall within one or
more of 26 specifically listed source categories. 40 CFR 51.301.
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[[Page 34577]]
In the August 15, 2012 Proposed FIP, the EPA conducted a five-
factor BART analysis for the Keetac facility.\10\ The EPA conducted
this five-factor analysis consistent with the BART Guidelines. In the
Original 2013 FIP Rule, the EPA determined that LNB technology is BART
for the Keetac facility and established NO<INF>X</INF> BART emission
limits based upon the performance of a specific LNB design that was
installed on taconite furnaces at U.S. Steel's Minntac taconite
facility. LNBs are widely used control devices proven to be effective
at reducing NO<INF>X</INF> from furnaces across many industrial sectors
and the EPA has not changed the Agency's determination that LNBs are
the appropriate BART control for Keetac. As discussed in the 2025
Proposed Rule, although the EPA based the initial LNB design selection
for Keetac on LNB operation at U.S. Steel's Minntac facility,
subsequent modeling demonstrated that, due to several technical
factors, the Minntac LNB design would be infeasible at Keetac.\11\
Subsequent studies instead determined that a different LNB main burner
design, in combination with low-NO<INF>X</INF> preheat burners, would
be feasible at Keetac and represented the most effective LNB design,
offering the highest technically feasible emission reductions for this
facility.\12\
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\10\ 77 FR 49312 (August 15, 2012).
\11\ See 2016-2-24 Barr Report with Appendices; 2016-5-13 FCT
Report (Redacted); 2018-8-08 Keetac Line II LNB technical analysis;
and 2018-8-08 Keetac Line II LNB technical analysis, in docket.
\12\ See 2019-2-27 Fives Main Burner Report (Redacted).pdf and
2019-6-28 Fives Preheat Burner Report (Redacted).pdf, in docket.
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Comment: The Conservation Groups contend that it is unreasonable
for the EPA to propose to relax the emission limits for NO<INF>X</INF>
from the furnace at the Keetac facility to allow more pollution.
Response: The EPA disagrees with the Conservation Groups'
assertions regarding the EPA's actions. Of note, Keetac has not yet
installed the identified NO<INF>X</INF> controls; therefore,
installation of any NO<INF>X</INF> controls--including those proposed
here--would result in NO<INF>X</INF> reductions compared to what the
Keetac facility is currently emitting. Therefore, compared to the
current and recent emissions at Keetac, the final rule does not allow
``more pollution.''
The RHR requires States (or in the case of a FIP, the EPA) to
develop an implementation plan that sets emission limits based on the
degree of reduction achievable through the application of the best
system of continuous emission reduction.\13\ As noted in this section
and as discussed in the 2025 Proposed Rule, the EPA conducted a five-
factor BART analysis in the Original 2013 FIP and determined that LNB
technology is BART for the Keetac facility. The EPA based the initial
LNB design selection for Keetac on LNB operation at U.S. Steel's
Minntac facility, but subsequent modeling demonstrated that, due to
several technical factors, the Minntac LNB design would be infeasible
at Keetac. Subsequent studies instead determined that a different LNB
main burner design, in combination with low-NO<INF>X</INF> preheat
burners, would be the most effective LNB design for Keetac, offering
the highest technically feasible emission reductions for this facility.
The BART limits proposed for Keetac reflect the degree of reduction
achievable based on the feasible LNB technology applied to operations
and parameters specific to the Keetac facility.
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\13\ See 40 CFR 51.301 ``Best Available Retrofit Technology
(BART).''
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Comment: The Conservation Groups contend that the EPA cannot merely
rely on only the engineering studies and data to ensure reasonable
progress toward natural visibility conditions.
Response: The EPA disagrees with the Conservation Groups' assertion
that the Agency is relying on engineering studies and data to ensure
reasonable progress. In this action, the EPA is promulgating
NO<INF>X</INF> BART emission limits for Keetac in accordance with the
BART determination set forth in the Original 2013 FIP Rule and refined
in the 2025 Proposed Rule for Keetac. The EPA is not promulgating a
long-term strategy or establishing reasonable progress goals for
Minnesota. On June 12, 2012, the EPA approved Minnesota's regional haze
plan for the first implementation planning period as satisfying the
applicable requirements in 40 CFR 51.308, except for BART emission
limits for the taconite facilities.\14\ Among the regional haze plan
elements approved were Minnesota's long-term strategy for making
reasonable progress toward visibility goals. Minnesota's long-term
strategy did not rely on the achievement of any particular degree of
emission control from the taconite facilities, including Keetac, to
achieve reasonable progress goals.
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\14\ 77 FR 34801 (June 12, 2012).
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Comment: The Conservation Groups contend that the EPA's proposed
action did not mention that the Agency already proposed revising the
Keetac emission limits in a prior proposed rulemaking. The Conservation
Groups claim that EPA must clarify the relationship between the
Agency's prior proposal and this one.
Response: The EPA disagrees with the Conservation Groups' assertion
that the EPA previously proposed to revise the NO<INF>X</INF> emission
limits for Keetac. Rather, on December 4, 2024, the EPA proposed a rule
which set forth reporting and recordkeeping requirements that apply to
all facilities subject to the Original 2013 FIP Rule and the Revised
2016 FIP Rule, including Keetac.\15\ Specifically, the EPA proposed to
require facilities subject to the Original 2013 FIP Rule and the
Revised 2016 FIP Rule, including Keetac, to submit reports
electronically and allow sources to supplement emission data if the
CEMS do not capture all data (e.g., during startup, shutdown, and
malfunction (SSM) conditions). The EPA did not propose emission limits
for Keetac in the December 4, 2024, proposed rule.
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\15\ 89 FR 96152 (December 4, 2024).
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Comment: The Conservation Groups assert that the EPA failed to
require that Keetac optimize its emission control system. The
Conservation Groups contend that the EPA must require that U.S. Steel
optimize the emission control system to meet the efficiencies that the
Agency identified as achievable. The Conservation Groups further
contend that there is no evidence that the ``variety of manufacturers
and engineering firms'' that U.S. Steel contracted with to ``evaluate
different NO<INF>X</INF> reduction technologies'' conducted their work
independently and that it appears the manufacturers and engineering
firms performed their work at the direction of U.S. Steel. The
Conservation Groups suggest that this raises concerns about biased
results that did not fully consider optimization.
Response: The EPA disagrees that the Agency must require Keetac to
optimize its emission control system. The Original 2013 FIP Rule did
not require that an affected taconite facility optimize its emission
control system; instead, it established limits based on expected
performance of the control technology. The proposed emission limits
reflect the degree of reduction achievable based on operation and
design parameters specific to the Keetac facility as specified in the
engineering reports.\16\ In addition, taconite facilities are subject
to the National Emission Standards for Hazardous Air Pollutants
(NESHAP) at 40 CFR 63, subpart RRRRR. As required by the general
provisions in the NESHAP, all affected taconite facilities are subject
to a
[[Page 34578]]
``general duty'' clause at 40 CFR 63.6(e) that requires all affected
facilities to ``at all times, including periods of startup, shutdown,
and malfunction, operate and maintain any affected source, including
associated air pollution control equipment and monitoring equipment, in
a manner consistent with safety and good air pollution control
practices for minimizing emissions.''
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\16\ See 2019-2-27 Fives Main Burner Report (Redacted).pdf and
2019-6-28 Fives Preheat Burner Report (Redacted).pdf, in docket.
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The EPA also disagrees with the Conservation Groups' contention
that the fact that the engineering firms performed their assessments at
the direction of U.S. Steel raises concerns about biased results.
Third-party engineering studies are common practice for facilities
seeking solutions to engineering challenges. Performing work on behalf
of U.S. Steel does not render the work product biased. As stated in the
2025 Proposed Rule, Keetac's pellet production is double that of
Minntac's, which affects the magnitude of fuel input, number and design
of combustion fans required, and burner system components needed to
successfully operate a burner. Therefore, Keetac required additional
evaluation to ensure the proposed solutions would work at this
facility. After reviewing, the EPA found no reason to disagree with the
engineering studies.
Comment: The Conservation Groups assert that the EPA does not have
the authority to ignore a clear statutory command to require BART in
the implementation plan merely by revising emission limits. Moreover,
the Conservation Groups claim that the EPA has never codified that BART
is determined at one time, and that courts will not uphold an EPA
action on a rationale that the Agency has never explained.
Response: The EPA disagrees with the Conservation Groups' assertion
that the Agency ignored the statutory obligation to require BART. As
discussed within this section, the EPA's BART determination for Keetac
was finalized in the Original 2013 FIP Rule. The EPA further disagrees
that this action requires a new BART analysis. BART was an explicit
first implementation period requirement and, as part of the first
implementation period, the EPA's BART determination for Keetac was
finalized in the Original 2013 FIP Rule. Therefore, there is no
requirement to re-evaluate BART controls for Keetac.
Comment: The Conservation Groups contend that the EPA failed to
articulate the Agency's rationale for determining that the prior BART
determination for Keetac still serves as a valid BART determination.
The Conservation Groups claim that the CAA makes clear that BART is a
mandatory part of ``each applicable implementation plan,'' and
expressly requires that States (or in the case of a FIP, the EPA)
``includ[e]'' BART for ``each'' eligible source.
Response: The EPA disagrees with the Conservation Groups'
contention that the Agency failed to articulate the Agency's rationale
for maintaining the prior BART determination as the current, valid BART
determination for this action. The EPA further disagrees that the CAA
requires that BART must be reevaluated in every regional haze SIP
revision. BART was an explicit first implementation period requirement
and, as part of the first implementation period, the EPA's BART
determination for Keetac was finalized in the Original 2013 FIP Rule.
CAA section 169A(b)(2)(A) requires ``each applicable implementation
plan'' to include requirements to install and operate BART. While the
CAA does not define the applicable implementation plans, the RHR does.
Under the RHR at 40 CFR 51.308(d), ``States were required to submit
SIPs addressing regional haze visibility impairment in 2007, which
covered what we refer to as the first implementation period (2008-
2018).'' \17\ For subsequent implementation periods under 40 CFR
51.308(f), ``[e]ach State identified in Sec. 51.300(b) must revise and
submit its regional haze implementation plan revision to the EPA by
July 31, 2021, July 31, 2028, and every 10 years thereafter.'' \18\
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\17\ See 82 FR 3078 (January 10, 2017 (the ``2017 RHR'').
\18\ 40 CFR 51.308(f).
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In the 2017 RHR, the EPA noted ``States were required to undertake
the BART determination process during the first implementation period.
The BART requirement was a one-time requirement . . . .'' \19\
Therefore, while CAA section 169A(b)(2)(A) requires ``each applicable
implementation plan'' to include requirements to go through the BART
determination process, the RHR establishes the various implementation
plan revisions under 40 CFR 51.308(b) and (f) and only requires
undergoing the BART determination process in the first implementation
plan revision under 40 CFR 51.308(e). The EPA finalized the Agency's
BART determination for Keetac in the Original 2013 FIP Rule, as part of
the first implementation period, and need not reevaluate BART controls
for Keetac. Therefore, there is no requirement to re-evaluate BART
controls for Keetac.
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\19\ 82 FR 3078, 3083 (January 10, 2017). See also August 2019
Guidance on Regional Haze State Implementation Plans for the Second
Implementation Period, at A-3, <a href="https://www.epa.gov/sites/default/files/2019-08/documents/8-20-2019_-_regional_haze_guidance_final_guidance.pdf">https://www.epa.gov/sites/default/files/2019-08/documents/8-20-2019_-_regional_haze_guidance_final_guidance.pdf</a>. ``BART. As a one-time
requirement during the first implementation period, 40 CFR 51.308(e)
directed states to evaluate potential BART controls at certain
larger, often uncontrolled, older stationary sources in order to
address visibility impacts from these sources. States were required
to conduct five-factor BART determinations for `BART-eligible'
sources that are anticipated to cause or contribute to any
visibility impairment in a Class I area. As an alternative to
requiring source-specific BART controls, states have the flexibility
to adopt an emissions trading program or other alternative program
as long as the alternative provides greater reasonable progress
towards improving visibility than BART and meets certain other
requirements set out in 40 CFR 51.308(e)(2).''
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Comment: The Conservation Groups contend that the EPA failed to
evaluate BART for Keetac to ensure that the proposed emission
limitation revisions satisfy BART factors. The Conservation Groups
assert that, to conduct compliant BART analyses for Keetac, the EPA
should have considered the available control train that the
Conservation Groups discuss in their 2024 Minnesota comments, which
likely would result in lower emissions limits than included in the
``taconite FIP'' as necessary to make reasonable progress. The
Conservation Groups contend that the EPA's proposed emission limitation
revisions fail to meet the regulatory or statutory test for BART.
Response: The EPA disagrees with the Conservation Groups' assertion
that the EPA failed to evaluate BART for Keetac. The EPA further
disagrees that the Conservation Groups' September 11, 2024 comments on
the Agency's proposed approval of Minnesota's Second Period Regional
Haze SIP revision are relevant to this action. First, as described in
this section, BART is a one-time requirement of the first planning
period, per the CAA, and the EPA determined BART for Keetac in the
Original 2013 FIP Rule.\20\ Second, the Keetac BART determination does
not preclude Minnesota from having considered other control options to
meet progress goals for the second planning period or beyond. Third,
the EPA proposed approval of Minnesota's Second Period Regional Haze
SIP revision on July 11, 2024. However, the EPA has not taken final
action on the SIP revision. The EPA will respond to comments submitted
on the Second Period SIP revision when taking final action on the SIP.
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\20\ See docket EPA-R05-OAR-2022-0974. Also available in the
docket for this action.
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Comment: The Conservation Groups assert the EPA must address their
numerous significant comments on this taconite source and the National
Park Service's Federal Land Managers consultation comments on available
controls for the taconite sources. These comments were submitted in
response
[[Page 34579]]
to the EPA's proposed approval of Minnesota's Second Planning Period
SIP revision.
Response: The EPA disagrees with the Conservation Groups' assertion
as described in this section. Additionally, the EPA has not taken final
action on Minnesota's Second Planning Period SIP revision. The EPA will
respond to comments submitted on the Second Period SIP revision,
including issues with respect to Federal Land Manager consultation,
when taking final action on that plan.
Comment: The Conservation Groups note that the EPA specifically
directed Minnesota to reconsider selective catalytic reduction (SCR)
with reheat as an available control option for taconite facilities and
contend that the Agency must evaluate this technology as BART for this
action.
Response: In 2016, the EPA stated ``We expect Minnesota and
Michigan to reevaluate SCR with reheat as a potential option for making
reasonable progress in future planning periods, but reject the
technology as BART for the Minnesota and Michigan taconite facilities
at this time.'' \21\ Thus, the EPA disagrees with the Conservation
Groups' assertion that the Agency must reconsider SCR with reheat as an
available BART control option for this action. As stated above, BART is
a one-time requirement of the first planning period. However, this BART
determination does not preclude Minnesota from reconsidering other
control options, including SCR with reheat, to meet progress goals for
the second planning period or beyond.
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\21\ 81 FR 21672, 21675.
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Comment: The Conservation Groups assert that the EPA wrongfully
withholds and redacts information from the public, thwarting meaningful
public participation, by withholding unspecified Fives North American
Combustion (FivesNA) information regarding anticipated NO<INF>X</INF>
performance derived from unspecified laboratory testing and field
installations, which contains redactions, and a February 24, 2016,
technical memorandum developed by Barr, ``Air Quality Regulatory
Analysis for Low NO<INF>X</INF> Burner Technology'' labeled ``U.S.
Steel Confidential Settlement Agreement Communication Subject to FRE
[Federal Rule of Evidence] 408,'' which contains redactions. The
Conservation Groups also contend the EPA proposes revising the BART
emission limitations based on the redacted (withheld) information,
without describing or providing a basis for withholding the
information, merely noting in the footnotes that the documents are
redacted.
The Conservation Groups assert that the information submitted by
FivesNA merely mentions the laboratory testing and field installation
studies and the EPA failed to include the detailed testing information
and studies in the proposed docket and that there is nothing to
indicate that the Agency received the underlying information and
reviewed and confirmed FivesNA's assertions. The Conservation Groups
contend that without the underlying information in the docket to
support the assertions, the public cannot review and comment on the
accuracy of the claims made.
Response: The EPA disagrees with the Conservation Groups' assertion
that the Agency is modifying the BART emission limits based on redacted
or withheld information. The docket for the 2025 Proposed Rule contains
all information necessary to substantiate the EPA's decision-making
process. The docket includes certain CBI-claimed information. Pursuant
to 40 CFR 2.301(a)(2), information otherwise qualifying as CBI cannot
be claimed as such if that information qualifies as ``emission data''
necessary for the EPA to disclose to demonstrate the feasibility,
practicability, or attainability of an existing or proposed standard or
limitation, under 40 CFR 2.301(a)(2)(ii)(B). Pursuant to 40 CFR
2.301(a)(2), ``emission data'' includes data necessary to determine the
amount of emissions that the Keetac facility is authorized to emit.
Here, redactions cover CBI-claimed information that does not qualify as
``emission data,'' and the EPA therefore does not need to include that
information in the 2025 Proposed Rule. With respect to the cited Barr
report, redacted information covered an economic analysis that
purported to establish the cost prohibitiveness of a specific
technology, but the EPA did not rely on purported cost prohibitiveness;
U.S. Steel otherwise demonstrated the technical infeasibility of that
technology.\22\ The cited Barr report is in the docket for the 2025
Proposed Rule because it provides background information on alternative
technologies that U.S. Steel and the EPA considered--and discarded--as
a feasible solution. The two FivesNA documents in the docket proposed
two FivesNA burner solutions to reduce NO<INF>X</INF> emissions at the
Keetac grate kiln. One document evaluated the Keetac main burner and
the other evaluated potential reductions at the preheat section of the
grate kiln. The redacted data in the two FivesNA documents were not
included in the docket because they were claimed as CBI and were not
material to the EPA's decisions on emission limits. They were also not
``emission data'' as defined at 40 CFR 2.301(a)(2) because they were
not necessary to determine the amount of emissions that the facility
would be authorized to emit. The docket for this rulemaking contains
all information necessary to substantiate the EPA's decision-making
process.
---------------------------------------------------------------------------
\22\ See 90 FR 17233, 17235-36.
---------------------------------------------------------------------------
Comment: The Conservation Groups contend that the EPA's reasons for
proposing the FIP revision are not moored to the CAA. Rather than
reducing pollution, the Conservation Groups assert that the proposed
changes would allow Keetac to emit more haze-forming pollution in the
future.
Response: The EPA disagrees that the reasons for proposing this
action are inconsistent with the requirements of the CAA. CAA section
169A establishes as a national goal the ``prevention of any future, and
the remedying of any existing, impairment of visibility in mandatory
Class I Federal areas which impairment results from manmade air
pollution.'' At a minimum, the CAA calls for SIPs to include a long-
term strategy and provisions for BART for certain major stationary
sources. The RHR codified and clarified the BART provisions at 40 CFR
51.308(e). As discussed in this section, the RHR requires States (or in
the case of a FIP, the EPA) to develop an implementation plan that sets
emission limits based on the degree of reduction achievable through the
application of the best system of continuous emission reduction. As
noted in this section and discussed in the 2025 Proposed Rule, the EPA
conducted five-factor BART analyses in the Original 2013 FIP Rule and
determined that LNB technology is BART for the Keetac facility. The
initial LNB design selection for Keetac was based on LNB operation at
U.S. Steel's Minntac facility and subsequent modeling demonstrated that
the Minntac LNB design would be infeasible at Keetac due to several
technical factors. Further studies determined that a different LNB main
burner design, in combination with low-NO<INF>X</INF> preheat burners,
would be the most effective LNB design for Keetac. The BART limits
proposed for Keetac in the 2025 Proposed Rule reflect the degree of
reduction achievable based on operations and parameters specific to the
Keetac facility.
Keetac has not yet installed the identified NO<INF>X</INF>
controls; therefore, installation of any NO<INF>X</INF> controls--
including those identified here--
[[Page 34580]]
necessarily result in NO<INF>X</INF> reductions compared to what the
Keetac facility is currently emitting.
Comment: The Conservation Groups assert that the 2025 Proposed Rule
fails to include the details necessary for practical enforceability.
The Conservation Groups further assert that the 2025 Proposed Rule
fails to explain how the proposed revised regulations identified for
inclusion in the FIP comply with the monitoring, recordkeeping, and
reporting requirements of the CAA and provide adequate reporting--
namely, CEMS compliance data--to the EPA for citizen enforcement.
Response: The EPA disagrees that the 2025 Proposed Rule for Keetac
had insufficient detail to ensure practical enforceability. The
regional haze regulations codified into the Minnesota SIP at 40 CFR
52.1235(c), (d), and (e) contain applicable monitoring, recordkeeping,
and reporting requirements, which satisfy the requirement in 42 U.S.C.
7410(a)(2)(F)(iii) and 40 CFR 51.211 for record maintenance and
periodic reporting. These requirements include semiannual compliance
reports and quarterly excess emission reports detailing compliance with
monitoring, recordkeeping, and reporting requirements.
Comment: The Conservation Groups contend that the 2025 Proposed
Rule fails to specify that emission limits apply at all times for
Keetac. The Conservation Groups also note that, although the EPA's
prior proposal included such a provision for the Northshore Mining
Company--Silver Bay facility (40 CFR 52.1235(b)(vi)), the Agency's
current proposal for Keetac lacks a similar provision. The Conservation
Groups assert that the EPA must act consistently and treat all the
taconite sources in the same manner.
Response: The EPA disagrees with the Conservation Groups'
contention that it was necessary for the 2025 Proposed Rule to specify
that emission limits apply at all times for Keetac because the Original
2013 FIP Rule already clearly requires that the emission limits apply
at all times and this action does not impact that provision. The
Original 2013 FIP Rule, codified at 40 CFR 52.1235(e)(7)(x)(A), clearly
states ``For purposes of this section, an excess emission is defined as
any 30-day or 720-hour rolling average period, including periods of
startup, shutdown, and malfunction, during which the 30-day or 720-hour
(as appropriate) rolling average emissions of either regulated
pollutant (SO<INF>2</INF> and NO<INF>X</INF>), as measured by a CEMS,
exceeds the applicable emission standards in this section'' (emphasis
added).
Comment: An anonymous commenter asserts that the EPA should not
loosen any standards ever. The anonymous commenter contends that the
EPA's mission is to clean the air and water and that clean means the
standard present before European arrival to America, and therefore the
Agency will never be able to loosen standards.
Response: The EPA disagrees with commenter's contentions. The EPA's
action is consistent with the CAA requirements and the applicable
implementing regulations. The EPA does not agree that the commenter's
summary of Agency's mission aligns with Congressional direction in the
text of the CAA and, therefore, the comment does not articulate an
applicable standard for this action. In this case, the EPA performed
analyses required by the CAA and applicable regulations, including a
BART analysis for Keetac, and determined that emission reductions based
on implementation of LNB technology is BART for this facility. When
Keetac installs this LNB technology at its facility, NO<INF>X</INF>
emissions will be reduced from current baseline levels.
Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
This action is not a significant regulatory action as defined in
Executive Order 12866 and is therefore not subject to a requirement for
Executive Order 12866 review.
B. Executive Order 14192: Unleashing Prosperity Through Deregulation
This action is considered an Executive Order 14192 deregulatory
action. This final rule provides burden reduction by promulgating less
stringent emission limits.
C. Paperwork Reduction Act (PRA)
This action does not impose an information collection burden under
the PRA.
D. Regulatory Flexibility Act (RFA)
I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA (5
U.S.C. 601 et seq.). This action will not impose any requirements on
small entities. This action will establish emission limits for one
taconite source. This source is not owned by a small entity, and
therefore, there are no impacts on small entities.
E. Unfunded Mandates Reform Act (UMRA)
This action does not contain any unfunded mandate as described in
UMRA, 2 U.S.C. 1531 through 1538, and does not significantly or
uniquely affect small governments. The action imposes no enforceable
duty on any State, local, or Tribal governments or the private sector.
F. Executive Order 13132: Federalism
This action does not have federalism implications. It will not have
substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government.
G. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
This rule does not have Tribal implications, as specified in
Executive Order 13175. It will not have substantial direct effects on
Tribal governments. Thus, Executive Order 13175 does not apply to this
rule. However, the EPA did discuss this action in conference calls with
the Minnesota Tribes.
H. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks
This action is not subject to Executive Order 13045 because it is
not 3(f)(1) significant as defined in Executive Order 12866.
I. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use
This action is not subject to Executive Order 13211 because it is
not a significant regulatory action under Executive Order 12866.
J. National Technology Transfer Advancement Act
This rulemaking does not involve technical standards.
K. Congressional Review Act
This rule is exempt from the Congressional Review Act because it is
a rule of particular applicability.
L. Judicial Review
Under section 307(b)(1) of the CAA, petitions for judicial review
of this action must be filed in the United States Court of Appeals for
the appropriate circuit by August 7, 2026. Filing a petition for
reconsideration by the Administrator of this final rule does not affect
the finality of this rule for the purposes of judicial review or extend
[[Page 34581]]
the time within which a petition for judicial review may be filed, and
shall not postpone the effectiveness of such rule or action. This
action may not be challenged later in proceedings to enforce its
requirements. See CAA section 307(b)(2).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Nitrogen oxides, Regional haze,
Reporting and recordkeeping requirements, and Sulfur oxides.
Lee Zeldin,
Administrator.
For the reasons stated in the preamble, title 40 CFR part 52 is
amended as follows:
PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS
0
1. The authority citation for part 52 continues to read as follows:
Authority: 42 U.S.C. 7401 et seq.
0
2. Section 52.1235 is amended by revising paragraph (b)(1)(i) to read
as follows:
Sec. 52.1235 Regional haze.
(a) [Reserved]
(b) * * *
(1) * * *
(i) United States Steel Corporation, Keetac--(A) Emission
limitations--(1) Natural gas limit. An emission limit of 3.4 lbs
NO<INF>X</INF>/MMBtu, based on a 720-hr rolling average, shall apply to
the Keetac Grate Kiln indurating furnace (EU030) when burning
exclusively natural gas. This emission limit shall become enforceable
beginning July 8, 2029.
(2) Limit when burning fuel other than exclusively natural gas. An
emission limit of 2.0 lbs NO<INF>X</INF>/MMBtu, based on a 720-hr
rolling average, shall apply to the Keetac Grate Kiln indurating
furnace when burning any fuel or combination of fuels other than
exclusively natural gas. This emission limit shall become enforceable
beginning July 8, 2029, unless before July 8, 2031, EPA promulgates a
modified limit in accordance with the procedures set forth in paragraph
(b)(1)(i)(C) of this section. The emission limit in this paragraph
shall apply unless adjusted as described in paragraph (b)(1)(i)(C)(3)
of this section, and only if the data submitted to EPA pursuant to
paragraph (b)(1)(i)(C)(1) of this section support such an adjustment.
(B) Installation of NO<INF>X</INF> reduction technology. The
NO<INF>X</INF> reduction technology shall be installed no later than
July 8, 2029.
(C) Process to modify emission limit when burning fuel other than
exclusively natural gas. If the owner or operator of Keetac requests to
modify the emission limit that applies when burning fuel other than
natural gas, then the owner or operator shall collect and submit data
and an engineering report to EPA in accordance with the following
process.
(1) Collection and reporting of data. The owner or operator of
Keetac shall submit to EPA data collected when burning any fuel or
combination of fuels other than exclusively natural gas during the
period following installation of the NO<INF>X</INF> reduction
technology until completion of 5,100 hours of data collection. Data
shall be submitted to EPA no later than 30 days after completion of
5100 hours of data collection and in any case no later than November 8,
2030. The data shall include hourly NO<INF>X</INF> emissions recorded
by CEMS in lbs NO<INF>X</INF>/MMBtu; hourly values of the operating
parameters identified in paragraph (b)(1)(i)(C)(2) of this section;
hourly process and CEMS information and codes; and hourly heat input in
MMBtu by fuel type. EPA will consider the data submitted in accordance
with the requirements of this paragraph and (b)(1)(i)(C)(3) of this
section. Data collected during the first 720 hours burning fuel other
than exclusively natural gas are considered the optimization period and
shall be submitted to EPA but shall not be included in the 4380 hours
of data considered for limit adjustment purposes. If the owner or
operator wishes to exclude any data from consideration due to pellet
quality concerns, then the owner or operator shall, to the extent
applicable, submit to EPA information regarding the following factors:
compression, reducibility, before tumble, after tumble, low temperature
disintegration, clustering, and swelling. For each of the pellet
quality analysis factors, the owner or operator must explain the pellet
quality analysis factor, as well as the defined acceptable range for
each factor using the applicable product quality standards based upon
customers' pellet specifications that are contained in Keetac's ISO
9001 quality management system. The owner or operator shall also
provide to EPA pellet quality analysis testing results that state the
date and time of the analysis and, in order to define the time period
when pellets were produced outside of the defined acceptable range for
the pellet quality factors listed, include copies of the production
logs that clearly define which hours of operation correspond to the
production of the pellets tested, and document which hours produced
pellets that met specifications and which hours produced pellets that
failed to meet specifications. The owner or operator shall report all
raw data in a format consistent with and able to be manipulated by
Microsoft Excel including formulas, as appropriate, in each cell.
(2) Engineering report. No later than 30 days after completion of
5100 hours of data collection and in any case no later than November 8,
2030, the owner or operator of Keetac shall submit to EPA a final
report including modeling demonstrating the selected NO<INF>X</INF>
reduction technology is designed to achieve NO<INF>X</INF> emissions no
greater than the emission limits specified in paragraph (b)(1)(i)(A)(2)
of this section and identifying the operating parameters and set points
upon which the modeling was based.
(3) Emission limit adjustment. If EPA determines that the data
submitted in accordance with paragraph (b)(1)(i)(C)(1) of this section
satisfy the criteria in that paragraph, then EPA shall use the
applicable equation set forth in paragraph (f) of this section to
determine whether adjustment of the emission limit set forth in
paragraph (b)(1)(i)(A)(2) of this section is appropriate. If revised,
the NO<INF>X</INF> emission limit when burning any fuel or combination
of fuels other than exclusively natural gas may be no greater than 2.5
lbs NO<INF>X</INF>/MMBtu, based on a 720-hr rolling average. The data
set used for the determination shall include only data that meet both
pellet quality specifications and optimized operating parameters
related to process and NO<INF>X</INF> reduction technology operation as
identified in paragraph (b)(1)(i)(C)(2) of this section. If the data
submitted pursuant to paragraph (b)(1)(i)(C)(1) of this section are
normally distributed and statistically independent, EPA shall use the
upper predictive limit (UPL) equation provided in paragraph (f)(1) of
this section. If the data submitted pursuant to paragraph
(b)(1)(i)(C)(1) of this section are not normally distributed or are
normally distributed but not statistically independent, EPA shall use
the non-parametric equation provided in paragraph (f)(2) of this
section. If, after receiving complete data from the owner or operator
as specified in (b)(1)(i)(C)(1) of this section, the results of the
equation support an emission limit other than 2.0 lbs NO<INF>X</INF>/
MMBtu when burning any fuel or combination of fuels other than
exclusively natural gas, EPA shall initiate a rulemaking to adjust the
emission limit. If the results
[[Page 34582]]
of the equation do not support an adjustment of the 2.0 lbs
NO<INF>X</INF>/MMBtu emission limit, then EPA shall take final agency
action to notify the owner or operator of Keetac in writing. If the
owner or operator does not submit data to EPA by January 8, 2031 in
accordance with paragraph (b)(1)(i)(C)(1) of this section for burning
any fuel or combination of fuels other than exclusively natural gas or
if EPA determines that the owner or operator did not provide complete
data supporting such an adjustment in accordance with paragraph
(b)(1)(i)(C)(1) of this section, then the 2.0 lbs NO<INF>X</INF>/MMBtu
emission limit shall remain in place and applicable.
(D) Compliance demonstration. Compliance with the emission limits
shall be demonstrated with hourly data collected by a continuous
emissions monitoring system for NO<INF>X.</INF> The CEMS shall be
continuously operated and maintained in accordance with 40 CFR part 60
Appendix F. CEMS records shall be maintained onsite for a period no
less than 5 years.
* * * * *
[FR Doc. 2026-11432 Filed 6-5-26; 8:45 am]
BILLING CODE 6560-50-P
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