[Federal Register Volume 90, Number 78 (Thursday, April 24, 2025)]
[Proposed Rules]
[Pages 17233-17239]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-07055]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R05-OAR-2024-0216; FRL-12599-01-R5]
Air Plan Approval; Minnesota; Revision to Taconite Federal
Implementation Plan
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
modify nitrogen oxide (NOX) emission limits for the
indurating furnace at United States Steel's (U.S. Steel's) Keetac
taconite facility in Keewatin, Minnesota (Keetac), to satisfy the
requirement for best available retrofit technology (BART) at taconite
facilities. EPA is proposing this action pursuant to sections 110 and
169A of the Clean Air Act (CAA).
DATES: Comments must be received on or before June 10, 2025.
Virtual Public Hearing. EPA is offering the opportunity for a
virtual public hearing to provide interested parties the opportunity to
present data, views, or arguments concerning the proposal. If anyone
contacts us requesting to present at a virtual public hearing on or
before May 6, 2025, EPA will hold a virtual public hearing on May 12,
2025. See SUPPLEMENTARY INFORMATION for information on registering and
requesting to present at a public hearing.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2024-0216 at https://www.regulations.gov, or via email to
[email protected]. For comments submitted at Regulations.gov, follow
the online instructions for submitting comments. Once submitted,
comments cannot be edited or removed from the
[[Page 17234]]
docket. EPA may publish any comment received to its public docket. Do
not submit to EPA's docket at https://www.regulations.gov any
information you consider to be Confidential Business Information (CBI),
Proprietary Business Information (PBI), or other information whose
disclosure is restricted by statute. Multimedia submissions (audio,
video, etc.) must be accompanied by a written comment. The written
comment is considered the official comment and should include
discussion of all points you wish to make. EPA will generally not
consider comments or comment contents located outside of the primary
submission (i.e., on the web, cloud, or other file sharing system). For
additional submission methods, please contact the person identified in
the FOR FURTHER INFORMATION CONTACT section. For the full EPA public
comment policy, information about CBI, PBI, or multimedia submissions,
and general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.
FOR FURTHER INFORMATION CONTACT: Gina Harrison, Environmental
Scientist, Air and Radiation Division (AR18J), Environmental Protection
Agency, Region 5, 77 West Jackson Boulevard, Chicago, Illinois 60604,
(312) 353-6956, [email protected]. The EPA Region 5 office is open
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding Federal
holidays.
SUPPLEMENTARY INFORMATION:
I. Participation in Virtual Public Hearing
To request to present at a virtual public hearing, or to pre-
register to attend the hearing, if one is held, please use the online
registration form available at https://www.epa.gov/mn/revision-taconite-regional-haze-federal-implementation-plan-mi-and-mn or contact
Mayesha Choudhury at (312) 886-5909 or by email at
[email protected]. EPA is asking all hearing attendees to
register, even those who do not intend to present. The last day to
request to present at the hearing will be May 6, 2025. If no request to
present at the virtual public hearing is received by 11:59 p.m. Central
Daylight Time (CDT) May 6, 2025, EPA will not hold the hearing. If a
virtual hearing is held, EPA will accept registration until the start
of the hearing.
EPA will announce the status of the hearing on May 7, 2025 on the
public hearing website at https://www.epa.gov/mn/revision-taconite-regional-haze-federal-implementation-plan-mi-and-mn. Alternatively,
interested parties may contact Mayesha Choudhury at (312) 886-5909 to
find out if the hearing is being held.
If a request to present at the virtual public hearing is received
by May 6, 2025, EPA will hold a virtual public hearing on May 12, 2025.
EPA will post a general agenda for the hearing on May 8, 2025. The
agenda will be available at https://www.epa.gov/mn/revision-taconite-regional-haze-federal-implementation-plan-mi-and-mn and will list pre-
registered presenters in approximate order. The hearing will convene at
9:00 a.m. CDT and will conclude at 1:00 p.m. CDT, or 15 minutes after
the last pre-registered presenter in attendance has presented if there
are no additional presenters. EPA will announce further details on the
virtual public hearing website at https://www.epa.gov/mn/revision-taconite-regional-haze-federal-implementation-plan-mi-and-mn.
If a request to present at the virtual public hearing is timely
received, EPA will make every effort to follow the schedule as closely
as possible on the day of the hearing; however, please plan for the
hearing to run either ahead of schedule or behind schedule. Each
commenter will have 5 minutes to provide oral testimony. EPA encourages
commenters to provide EPA with a written copy of their oral testimony
electronically by including it in the registration form or emailing it
to [email protected]. EPA may ask clarifying questions during
the oral presentations but will not respond to the presentations at
that time. Written statements and supporting information submitted
during the comment period will be considered with the same weight as
oral comments and supporting information presented at the virtual
public hearing.
Please note that any updates made to any aspect of the hearing will
be posted online at https://www.epa.gov/mn/revision-taconite-regional-haze-federal-implementation-plan-mi-and-mn. Please monitor our website
or contact Mayesha Choudhury at (312) 886-5909 or
[email protected] to determine if there are any updates. EPA
does not intend to publish a document in the Federal Register
announcing updates concerning the virtual public hearing.
If you require the services of a translator or a special
accommodation such as audio description/closed captioning, please pre-
register for the hearing with Mayesha Choudhury at (312) 886-5909 or
[email protected] and describe your needs by May 5, 2025. EPA
may not be able to arrange accommodations without advance notice.
II. Background
A. Requirements of the CAA and EPA's Regional Haze Rule
In the CAA Amendments of 1977, Congress created a program for
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 \1\ 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.
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\1\ Areas designated as mandatory Class I Federal areas consist
of national parks exceeding 6,000 acres, wilderness areas and
national memorial parks exceeding 5,000 acres, and all international
parks that were in existence on August 7, 1977. 42 U.S.C. 7472(a).
In accordance with section 169A of the CAA, EPA, in consultation
with the Department of Interior, promulgated a list of 156 areas
where visibility is identified as an important value. 44 FR 69122
(November 30, 1979). The extent of a mandatory Class I area includes
subsequent changes in boundaries, such as park expansions. 42 U.S.C.
7472(a). Although states and Tribes may designate as Class I
additional areas which they consider to have visibility as an
important value, the requirements of the visibility program set
forth in section 169A of the CAA apply only to ``mandatory Class I
Federal areas.'' Each mandatory Class I Federal area is the
responsibility of a ``Federal Land Manager.'' 42 U.S.C. 7602(i).
When we use the term ``Class I area'' in this action, we mean a
``mandatory Class I Federal area.''
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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
[[Page 17235]]
sources \2\ built between 1962 and 1977 procure, install, and operate
BART \3\ as determined by EPA.
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\2\ The set of ``major stationary sources'' potentially subject
to BART is listed in CAA section 169A(g)(7) and includes ``taconite
ore processing facilities.''
\3\ 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.'' \4\ 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.\5\
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\4\ ``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.
\5\ 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 (SO2), NOX, 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).
B. BART FIP and Regulatory History for the Keetac Taconite Facility
On February 6, 2013 (78 FR 8706), EPA promulgated a FIP that
included NOX BART limits for indurating furnaces at seven
taconite facilities subject to BART in Minnesota and Michigan
(``Original 2013 FIP Rule''). The Original 2013 FIP Rule included
NOX BART limits for indurating furnaces at two U.S. Steel
taconite facilities located in Minnesota--Keetac and Minntac. EPA took
this action because Minnesota and Michigan had failed to meet a
statutory deadline to submit their regional haze SIPs for the first
planning period by December 17, 2007, and subsequently failed to
require BART at the taconite facilities. The Original 2013 FIP Rule,
among other requirements, established NOX BART emission
limits of 1.2 pounds (lbs) of NOX per million British
Thermal Unit (MMBtu) when burning natural gas and 1.5 lbs
NOX/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 performance of high stoichiometric
(high-stoich) low-NOX burners (LNBs) installed on taconite
furnaces at Minntac.
In a related action, on September 30, 2013 (78 FR 59825), EPA
finalized partial disapprovals of Minnesota and Michigan's regional
haze SIPs for the first planning period for failing to require BART for
the indurating furnaces at taconite facilities (``SIP Disapprovals'').
Among other things, EPA found that Minnesota and Michigan had erred by
determining that an undefined set of ``good combustion practices''
represented NOX BART for Keetac and six other taconite
facilities when U.S. Steel had successfully installed LNBs on Lines 6
and 7 at Minntac.
Subsequently, U.S. Steel filed a petition for review of the SIP
Disapprovals in the U.S. Court of Appeals for the Eighth Circuit
(``Eighth Circuit'') and submitted to EPA a petition for
reconsideration of the SIP Disapprovals. In its petitions for review
and reconsideration of the SIP Disapprovals, U.S. Steel simultaneously
sought review and reconsideration of the Original 2013 FIP Rule.
On April 12, 2016 (81 FR 21672), EPA promulgated a revised FIP
rule, which revised BART emission limits for certain taconite
facilities owned by companies other than U.S. Steel (``2016 Revised FIP
Rule''). Those companies, along with U.S. Steel, each filed a petition
for review in the Eighth Circuit challenging the 2016 Revised FIP Rule.
U.S. Steel also submitted to EPA a petition for reconsideration of the
2016 Revised FIP Rule.
On December 4, 2017 (82 FR 57125), EPA denied U.S. Steel's
petitions for reconsideration of the Original 2013 FIP Rule, the SIP
Disapprovals, and the 2016 Revised FIP Rule (``Denial of
Reconsideration''). U.S. Steel filed a petition for review in the
Eighth Circuit challenging EPA's Denial of Reconsideration. U.S.
Steel's challenge of the Denial of Reconsideration has been in abeyance
while the parties have been working toward resolution.
In November 2019, EPA executed a Settlement Agreement with U.S.
Steel pertaining to NOX BART requirements at Minntac.\6\ EPA
subsequently proposed and finalized a FIP revision addressing
NOX BART requirements for Minntac.\7\ Most recently, in
September 2024, EPA executed a Settlement Agreement with U.S. Steel
pertaining to NOX BART requirements at Keetac.\8\
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\6\ See 84 FR 47945 (September 11, 2019) (Minntac proposed
Settlement Agreement).
\7\ See 85 FR 6125 (February 4, 2020) (Minntac proposed FIP
revision); 86 FR 12095 (March 2, 2021) (Minntac final rule revising
FIP).
\8\ See 89 FR 30357 (April 23, 2024) (Keetac proposed Settlement
Agreement).
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III. Basis for NOX Limits
The Original 2013 FIP Rule limits were set based upon the
performance of high-stoich LNBs on indurating furnaces at Minntac.
Between its two taconite facilities (Minntac and Keetac), U.S. Steel
owns and operates six grate-kiln taconite furnaces: five indurating
furnaces at Minntac, and one large indurating furnace at Keetac. While
all six furnaces are of generally similar design, they each differ in
size, gas flow, combustion air design, production throughput, fuels
used, type of taconite pellets produced, and heat characteristics in
the furnace, among
[[Page 17236]]
other differences.\9\ 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.\10\
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\9\ See 2014-7-18 U.S. Steel's Response to EPA's questions;
2017-2-15 USS response to EPAs concerns re Keetac Low NOX
burner costs analysis; and 2020-8-14 August 7 2020 Call follow-up
answers from US Steel, in docket.
\10\ See 2014-7-18 U.S. Steel's Response to EPA's questions, in
docket.
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Between 2009 and 2019, U.S. Steel contracted a variety of
manufacturers and engineering firms to evaluate different
NOX reduction technologies that could meet the requirements
of the Original 2013 FIP Rule at its Minntac and Keetac facilities,
which both operate grate-kiln indurating furnaces. Early computational
fluid dynamics modeling performed by these contractors showed that a
high-stoich low-NOX burner system would be a feasible option
at Minntac. This testing showed that low-NOX main burner
systems, when used in conjunction with other modifications, could
achieve a significant decrease in NOX emissions at those
furnaces.
U.S. Steel also conducted NOX reduction demonstrations
with a selective non-catalytic reduction (SNCR) system at Minntac. The
results of this testing at Minntac showed that SNCR could produce, at
best case, 8-10% NOX reduction from baseline NOX
emission levels at Minntac, and also in some cases a net increase in
NOX emissions with urea injected at the entrance to the
preheater.\11\ In 2011, U.S. Steel reported the successful pilot
testing of a low-NOX main burner system on Line 7 at
Minntac.\12\ Based on this testing at Minntac, U.S. Steel identified
LNBs as the most effective method of reducing NOX emissions
from the indurating process and evaluated the feasibility of installing
LNBs at Keetac. However, the emission and process data generated
through subsequent modeling indicated that this specific LNB technology
developed for Minntac would not consistently achieve the same results
on all taconite indurating furnaces while operating under various fuel
use and production scenarios while maintaining pellet quality.\13\
Keetac's pellet production is double that of Minntac's, which affects
the magnitude of the fuel input, the number and design of combustion
fans required, and the burner system components needed to successfully
operate a burner. Subsequent modeling and engineering studies
determined that a new low-NOX main burner at Keetac would
require additional natural gas and, as a result, would need double the
amount of air to maintain an appropriate combustion efficiency.\14\
These additional requirements were deemed infeasible at Keetac due to
several technical factors, including the need to maintain appropriate
temperature profiles to ensure pellet quality, space and design
constraints, and significant safety concerns.
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\11\ See 2009-10-26 Nalco Mobotec US Steel Minntac Line 7 Final
Report EPA-R05-OAR-2010-0037-0037_attachment_42, in docket.
\12\ See 2011-05-13 USS Minntac Final test results Line 7
burner, in docket.
\13\ See 2012-09-14 Metso Cliffs Tilden modeling report; 2014-
07-20 Cliffs UTAC FCT phase 3 modeling report; 2014-08-07 Metso UTAC
LNB Grate Kiln L2 study; and 2015-01-13 Metso Cliffs Tilden I Phase
III COEN LNB modeling report, in docket.
\14\ See 2016-2-24 Barr Report with Appendices; 2016-5-13 FCT
Report (Redacted); and 2018-8-08 Keetac Line II LNB technical
analysis, in docket.
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In 2017, EPA asked U.S. Steel to evaluate additional technology
options for Keetac, including evaluating application of water injection
to the burner system, providing temperature data for further evaluation
of SNCR, further engaging with burner manufacturers to design a low-
NOX main burner, and investigating the potential addition of
preheat burners. A subsequent study of water injection at Keetac
indicated that water injection would result in a significant reduction
in pellet production along with adverse effects to pellet quality.\15\
U.S. Steel also collected process data to further evaluate the
feasibility of SNCR at Keetac. Based on process temperature
measurements, the downdraft drying sections are too cold or below the
temperature window for SNCR injection, while the preheat section is too
hot and above the temperature window. In addition, due to physical
space limitations and flue gas velocity, adequate residence time is not
available for the reaction to take place. Consequently, the facility-
specific conditions of the operating line at Keetac do not allow for a
suitable location to inject urea for SNCR.\16\
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\15\ See 2019-2-08 Metso Keetac Water Injection Analysis study,
in docket.
\16\ See 2017-4-13 USS Keetac Grate Diagram and Supporting
Information, in docket.
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U.S. Steel provided process and emission data and studies that set
forth its concerns regarding potentially serious impacts from high-
stoich LNB operation on the overall operation of the furnace, such as
the heat balance of the furnace, the fuel used, pellet quality,
airflow, safety, and other factors. U.S. Steel provided another
engineering report containing a detailed analysis of how Keetac's
process and pellet quality would be affected by changes to the burner
operating parameters required to incorporate a high-stoich LNB
system.\17\ The studies analyzed the effects of low and mid-stoich LNB
systems on the Keetac furnace by using simulation modeling that
compared Keetac's normal operating conditions with simulations of
furnace operations while using LNBs with a higher stoichiometric rate,
showing that a low-stoich LNB system may be a viable option to reduce
NOX emissions from the Keetac furnace, with the potential
for additional reductions from preheat burners.
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\17\ Engineering report by Metso dated August 8, 2018
``Technical Analysis for applying LNB technology to Keetac Line II
Grate Kiln (GK) system.''
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Following evaluation of these engineering studies and data, EPA
concluded that while the specific LNB design implemented at Minntac
would not be appropriate for Keetac, LNB continues to be the
appropriate selection for BART at Keetac. Specifically, installation of
a low-NOX main burner combined with low-NOX
preheat burners is expected to yield a 40-45% NOX reduction
when compared to baseline emissions from a standard burner.\18\
Modeling of the Keetac indurating furnace with a low-NOX
main burner in conjunction with low-NOX preheat burners
indicated that a limit of 3.4 lbs NOX/MMBtu represents BART
for Keetac when firing exclusively natural gas.\19\ Modeling of a low-
NOX main burner also indicated that a limit of 2.0 lbs
NOX/MMBtu represents BART during production cycles when
cofiring with coal.\20\ Modeling of mixed fuel production scenarios
only reflects reductions based on the operation of the main burner
since data indicate that reductions from preheat burners in these
scenarios are limited.\21\
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\18\ Modeling used baseline emission values of 6.0-6.2 lbs
NOX/MMBtu and predicted a range of 40-45% reduction in
NOX emissions while utilizing exclusively natural gas
when operating both a main burner and preheat burners. See 2019-2-27
Fives Main Burner Report (Redacted) and 2019-6-28 Fives Preheat
Burner Report (Redacted), in docket.
\19\ See 2019-6-28 Fives Preheat Burner Report (Redacted).
\20\ See 2019-2-27 Fives Main Burner Report (Redacted).
\21\ See 2019-8-26 USS proposed solid fuel limit justification
email and 2020-6-26 USS Email re solid fuels, in docket.
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Based on this most recent modeling data, EPA is proposing to
replace the existing NOX BART emission limits applicable to
Keetac with the following NOX BART emission limits: (1) 3.4
lbs NOX/MMBtu on a 720-hour rolling average when firing
exclusively natural gas, which will become enforceable beginning three
years after promulgation
[[Page 17237]]
of a final rule, and (2) a NOX BART limit of 2.0 lbs
NOX/MMBtu on a 720-hour rolling average when burning any
fuel or combination of fuels other than exclusively natural gas, which
will become enforceable five years after promulgation of a final rule,
with the option for the owner or operator to seek an adjustment up to
2.5 lbs NOX/MMBtu as discussed below. These values are based
on modeling the use of both low-NOX preheat burners and a
low-NOX main burner when firing exclusively natural gas and
the use of a low-NOX main burner when utilizing mixed fuels.
Due to the facility not utilizing mixed fuels after 2013, the
modeling could not be validated for cofiring scenarios. Therefore, EPA
is proposing to allow the owner or operator of Keetac, within a period
of 52 months from the effective date of the final rule, the option to
seek an adjustment of the NOX BART cofiring emission limit
based on collection of Continuous Emission Monitoring System (CEMS)
data after installation of the NOX-reduction technology.\22\
EPA is proposing that, upon receipt of complete emissions data from the
owner or operator of Keetac as described in paragraph (b)(1)(i)(C)(1)
of the proposed regulatory text, EPA will evaluate whether the data
support adjusting the NOX BART emission limit while burning
any fuel or combination of fuels other than exclusively natural gas
using the applicable equation set forth in 40 CFR 52.1235(f). If the
results of the equation support adjustment of the NOX BART
emission limit, EPA shall initiate a rulemaking to adjust the emission
limit. If revised, the NOX BART emission limit when burning
any fuel or combination of fuels other than exclusively natural gas may
be no greater than 2.5 lbs NOX/MMBtu, based on a 720-hour
rolling average.
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\22\ Per the Regional Haze rule, each source subject to BART is
required to install and operate BART within 5 years--60 months--of
plan approval. To allow EPA sufficient time to review a cofiring
adjustment request and take action on that request within the 60-
month timeframe, EPA must receive the initial request within 52
months of this final rule. EPA is allowing two additional months for
data completion and sufficiency review, for a final request
completion deadline of 54 months. If EPA does not receive a complete
cofiring adjustment request by 54 months after the final rule, then
the 2.0 lbs/MMBtu limit shall remain in place and applicable.
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EPA's visibility impact analysis in the 2013 FIP was based on the
assumption of a 70% reduction in NOX emissions when firing
natural gas. EPA now anticipates a 40-45% reduction in NOX
emissions when firing natural gas as a result of the control
technologies and associated emission limits proposed in this
rulemaking.\23\ EPA expects the Keetac LNB design to achieve
substantial visibility improvements, although slightly less than what
was projected to be achieved in the Original 2013 FIP Rule, in an
amount roughly corresponding to the decrease in emission reductions.
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\23\ Modeling used baseline emission values of 6.0-6.2 lbs
NOX/MMBtu and predicted a range of 40-45% reduction in
NOX emissions while utilizing exclusively natural gas
when operating both a main burner and preheat burners. See 2019-2-27
Fives Main Burner Report (Redacted) and 2019-6-28 Fives Preheat
Burner Report (Redacted), in docket.
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IV. CAA Section 110(l)
Under CAA section 110(l), EPA cannot approve a plan revision ``if
the revision would interfere with any applicable requirement concerning
attainment and reasonable further progress (as defined in section 7501
of this title), or any other applicable requirement of this chapter.''
Based on the following analysis, we find that EPA's approval of this
revision is consistent with CAA section 110(l) because it will not
interfere with any applicable requirement concerning attainment,
reasonable further progress, or any other applicable requirements of
the CAA.
On June 12, 2012 (77 FR 34801), EPA approved Minnesota's regional
haze plan for the first planning period as satisfying the applicable
requirements in 40 CFR 51.308, except for BART emission limits for the
taconite facilities. As previously discussed, EPA promulgated the
Original 2013 FIP Rule to address the BART requirement for taconite
facilities. The BART limits set forth in the Original 2013 FIP Rule
were based on a LNB designed for Minntac. For reasons discussed above,
U.S. Steel was unable to implement this LNB design at Keetac. Years of
engineering studies and analysis identified an available LNB design
solution for Keetac that will achieve NOX reductions at the
Keetac furnace. Since this analysis concluded Keetac could not meet the
limits set forth in the Original 2013 FIP Rule, EPA is setting higher
proposed BART limits that reflect the emission reductions achievable
using the Keetac LNB design solution. EPA is proposing that these
limits represent BART and therefore the BART requirements of the CAA
are satisfied.
Minnesota's 2012 long-term strategy for making reasonable progress
towards the national visibility goal was among the regional haze plan
elements approved by EPA. Minnesota's 2012 long-term strategy did not
rely on the achievement of any particular degree of emission control
from the taconite facilities; therefore, the revised NOX
BART emission limits for Keetac represent greater control than was
assumed in Minnesota's approved SIP and do not interfere with the
reasonable progress goals required by 40 CFR 51.308(d)(1), as set forth
in Minnesota's first planning period SIP.
With respect to requirements concerning attainment of the National
Ambient Air Quality Standards (NAAQS) and reasonable further progress,
all areas in Minnesota are designated as attainment for all NAAQS that
are potentially impacted by NOX emissions.\24\ Outside the
state, the nearest ozone, particulate matter, or nitrogen dioxide
nonattainment areas are the areas designated as nonattainment for the
2015 ozone NAAQS located along the western shore of Lake Michigan. The
nearest of these ozone nonattainment areas along the western Lake
Michigan shoreline, Sheboygan County, Wisconsin, is over 350 miles from
Keewatin, Minnesota. At the time these areas were designated as
nonattainment for the 2015 ozone NAAQS, EPA evaluated HYSPLIT (Hybrid
Single-Particle Lagrangian Integrated Trajectory) trajectories to
identify areas potentially contributing to monitored violations of the
NAAQS. No areas designated as nonattainment for the 2015 ozone NAAQS
showed trajectories indicating that emissions from the area near
Keewatin, Minnesota, had the potential to contribute to any of the
monitored violations of the ozone NAAQS.
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\24\ The only nonattainment area in Minnesota is the Dakota
County lead nonattainment area in Eagan, MN which is not impacted by
NOX emissions.
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Therefore, based on the information presented above, we find that
EPA's approval of these revisions would be consistent with CAA section
110(l). The proposed FIP revision complies with applicable regional
haze requirements and general implementation plan requirements and does
not interfere with any regional haze program requirements, attainment
and reasonable further progress, or any other requirement of the CAA.
V. Proposed Action
EPA is proposing to modify NOX BART emission limits for
the indurating furnace at Keetac. Specifically, EPA is proposing to
approve the following NOX 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 NOX/MMBtu when
firing exclusively natural gas, which will become
[[Page 17238]]
enforceable beginning three years after promulgation of a final rule,
and (2) 2.0 lbs NOX/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, EPA promulgates a modified limit in accordance
with the following procedure. EPA is also proposing 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 NOX/MMBtu as a 720-hour rolling
average, based on collection of CEMS data after installation of the
NOX reduction technology.
VI. Statutory and Executive Order Reviews
Additional information about these statutes and executive orders
can be found at https://www.epa.gov/laws-regulations/laws-and-executive-orders.
A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review 13563
This action is exempt from review by the Office of Management and
Budget (OMB), as it is not a rule of general applicability. This
action, if finalized, will specifically regulate the Keetac taconite
facility in Minnesota.
B. Executive Order 14192: Unleashing Prosperity Through Deregulation
Executive Order 14192 does not apply because actions that are rules
of particular applicability are exempt from review under Executive
Order 12866. This action, if finalized, will specifically regulate the
Keetac taconite facility in Minnesota.
C. Paperwork Reduction Act
This proposed action does not impose an information collection
burden under the provisions of the Paperwork Reduction Act, 44 U.S.C.
3501 et seq. Under the Paperwork Reduction Act, a ``collection of
information'' is defined as a requirement for ``answers to . . .
identical reporting or recordkeeping requirements imposed on ten or
more persons . . . .'' 44 U.S.C. 3502(3)(A). Because the FIP applies to
one taconite facility in Minnesota, the Paperwork Reduction Act does
not apply. See 5 CFR 1320(c).
D. Regulatory Flexibility Act (RFA)
I certify that this proposed action will not have a significant
economic impact on a substantial number of small entities under the
RFA. This proposed action will not impose any requirements on small
entities. This action, if finalized, will add additional controls to
one taconite source. This source, the Keetac taconite facility, is not
owned by small entities, and therefore is not a small entity.
E. Unfunded Mandates Reform Act (UMRA)
This proposed action does not contain any unfunded mandate as
described in UMRA, 2 U.S.C. 1531-1538, and does not significantly or
uniquely affect small governments. The proposed action imposes no
enforceable duty on any state, local or Tribal governments or the
private sector.
F. Executive Order 13132: Federalism
This proposed 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 proposed action 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 action. Consistent with the EPA Policy on Consultation
and Coordination with Indian Tribes, EPA consulted with Tribal
officials during the development of this action. On April 25, 2024, we
met with Tribal leaders and presented an overview of the upcoming
Keetac action. We encouraged the Tribes to contact us with any
questions. Since that meeting we have provided updates on several
monthly Tribal calls.
H. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
This action is not subject to Executive Order 13045 because it is
not economically significant as defined in Executive Order 12866, and
because EPA does not believe the environmental health or safety risks
addressed by this action present a disproportionate risk to children.
To the extent this action, if finalized, will limit emissions of
NOX emissions, the rule will have a beneficial effect on
children's health by reducing air pollution.
I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
This action is not subject to Executive Order 13211 (66 FR 28355,
May 22, 2001), because it is not a significant regulatory action under
Executive Order 12866.
J. National Technology Transfer and Advancement Act
This rulemaking does not involve technical standards.
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.
Lee Zeldin,
Administrator.
For the reasons stated in the preamble, EPA proposes to amend 40
CFR part 52 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
3. Section 52.1235 is proposed to be amended by revising paragraph
(b)(1)(i) to read as follows:
Sec. 52.1235 Regional haze.
(a) [Reserved]
(b) * * *
(1) NOX emission limits.
(i) United States Steel Corporation, Keetac.
(A) Emission limitations.
(1) Natural gas limit. An emission limit of 3.4 lbs NOX/
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 [DATE 3
YEARS AFTER THE EFFECTIVE DATE OF FINAL RULE].
(2) Limit when burning fuel other than exclusively natural gas. An
emission limit of 2.0 lbs NOX/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 [DATE 5 YEARS AFTER EFFECTIVE DATE OF FINAL RULE], unless
before [DATE 5 YEARS AFTER EFFECTIVE DATE OF FINAL
[[Page 17239]]
RULE], EPA promulgates a modified limit in accordance with the
procedures set forth in paragraph (b)(1)(i)(C). The emission limit in
this paragraph shall apply unless adjusted as described in paragraph
(b)(1)(i)(C)(3), and only if the data submitted to EPA pursuant to
paragraph (b)(1)(i)(C)(1) support such an adjustment.
(B) Installation of NOX reduction technology. The NOX
reduction technology shall be installed no later than [DATE 3 YEARS
AFTER EFFECTIVE DATE OF FINAL RULE].
(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 NOX reduction
technology until completion of 5100 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 [DATE 52
MONTHS AFTER EFFECTIVE DATE OF FINAL RULE]. The data shall include
hourly NOX emissions recorded by CEMS in lbs NOX/
MMBtu; hourly values of the operating parameters identified in
paragraph (b)(1)(i)(C)(2); 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). 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 [DATE 52
MONTHS AFTER EFFECTIVE DATE OF FINAL RULE], the owner or operator of
Keetac shall submit to EPA a final report including modeling
demonstrating the selected NOX reduction technology is
designed to achieve NOX emissions no greater than the
emission limits specified in paragraph (b)(1)(i)(A)(2) 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) satisfy the
criteria in that paragraph, then EPA shall use the applicable equation
set forth in paragraph (f) to determine whether adjustment of the
emission limit set forth in paragraph (b)(1)(i)(A)(2) is appropriate.
If revised, the NOX emission limit when burning any fuel or
combination of fuels other than exclusively natural gas may be no
greater than 2.5 lbs NOX/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 NOX reduction
technology operation as identified in paragraph (b)(1)(i)(C)(2). If the
data submitted pursuant to paragraph (b)(1)(i)(C)(1) are normally
distributed and statistically independent, EPA shall use the upper
predictive limit (UPL) equation provided in paragraph (f)(1). If the
data submitted pursuant to paragraph (b)(1)(i)(C)(1) are not normally
distributed or are normally distributed but not statistically
independent, EPA shall use the non-parametric equation provided in
paragraph (f)(2). If, after receiving complete data from the owner or
operator as specified in (b)(1)(i)(C)(1), the results of the equation
support an emission limit other than 2.0 lbs NOX/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 of the equation do not support an adjustment of the 2.0 lbs
NOX/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 [DATE 54 MONTHS AFTER
EFFECTIVE DATE OF FINAL RULE] in accordance with paragraph
(b)(1)(i)(C)(1) 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), then the 2.0 lbs
NOX/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 NOX. 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. 2025-07055 Filed 4-23-25; 8:45 am]
BILLING CODE 6560-50-P