Proposed Rule2026-03936
Air Plan Approvals; Illinois; Regional Haze Plan for the Second Implementation Period; Interstate Transport of Air Pollution for the 2012 PM2.5 and 2015 Ozone NAAQS
Primary source
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Published
February 27, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is proposing to approve the regional haze State Implementation Plan (SIP) revision submitted by the Illinois Environmental Protection Agency (Illinois EPA) on June 3, 2024, as satisfying applicable requirements under the Clean Air Act (CAA) and the EPA's Regional Haze Rule for the program's second implementation period. The EPA proposes to find that Illinois' regional haze SIP submission fulfills the requirement that States must periodically revise their long-term strategies for making reasonable progress towards the national goal of preventing any future, and remedying any existing, anthropogenic impairment of visibility in mandatory Class I Federal areas. The EPA is also proposing to approve portions of Illinois' September 29, 2017, and May 16, 2019, infrastructure SIP submissions for the 2012 fine particulate matter (PM<INF>2.5</INF>) and 2015 ozone National Ambient Air Quality Standards (NAAQS), respectively. The EPA is proposing that Illinois' infrastructure submissions fulfill CAA requirements for a State's SIP to contain adequate provisions prohibiting emissions that will interfere with required visibility protection measures in any other State's SIP.
Full Text
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<title>Federal Register, Volume 91 Issue 39 (Friday, February 27, 2026)</title>
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[Federal Register Volume 91, Number 39 (Friday, February 27, 2026)]
[Proposed Rules]
[Pages 9779-9793]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-03936]
[[Page 9779]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R05-OAR-2017-0583; EPA-R05-OAR-2019-0311; EPA-R05-OAR-2024-0261;
FRL-13083-01-R5]
Air Plan Approvals; Illinois; Regional Haze Plan for the Second
Implementation Period; Interstate Transport of Air Pollution for the
2012 PM2.5 and 2015 Ozone NAAQS
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
approve the regional haze State Implementation Plan (SIP) revision
submitted by the Illinois Environmental Protection Agency (Illinois
EPA) on June 3, 2024, as satisfying applicable requirements under the
Clean Air Act (CAA) and the EPA's Regional Haze Rule for the program's
second implementation period. The EPA proposes to find that Illinois'
regional haze SIP submission fulfills the requirement that States must
periodically revise their long-term strategies for making reasonable
progress towards the national goal of preventing any future, and
remedying any existing, anthropogenic impairment of visibility in
mandatory Class I Federal areas. The EPA is also proposing to approve
portions of Illinois' September 29, 2017, and May 16, 2019,
infrastructure SIP submissions for the 2012 fine particulate matter
(PM<INF>2.5</INF>) and 2015 ozone National Ambient Air Quality
Standards (NAAQS), respectively. The EPA is proposing that Illinois'
infrastructure submissions fulfill CAA requirements for a State's SIP
to contain adequate provisions prohibiting emissions that will
interfere with required visibility protection measures in any other
State's SIP.
DATES: Written comments must be received on or before March 30, 2026.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2024-0261 (Regional Haze) or EPA-R05-OAR-2019-0311 (infrastructure
SIPs) at <a href="https://www.regulations.gov">https://www.regulations.gov</a> or via email to
<a href="/cdn-cgi/l/email-protection#1d717c737a707c733370747e757c78715d786d7c337a726b"><span class="__cf_email__" data-cfemail="224e434c454f434c0c4f4b414a43474e624752430c454d54">[email protected]</span></a>. For comments submitted at <a href="http://Regulations.gov">Regulations.gov</a>,
follow the online instructions for submitting comments. Once submitted,
comments cannot be edited or removed from the docket. The EPA may
publish any comment received to its public docket. Do not submit to the
EPA's docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> 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. The EPA will generally not consider comments or comment
contents located outside of the primary submission (i.e., on the web,
cloud, or other file sharing system). For additional submission
methods, please contact the person identified in the FOR FURTHER
INFORMATION CONTACT section. For the full EPA public comment policy,
information about CBI or multimedia submissions, and general guidance
on making effective comments, please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
FOR FURTHER INFORMATION CONTACT: Kelsey Foss, Air and Radiation
Division (AR-18J), Environmental Protection Agency, Region 5, 77 West
Jackson Boulevard, Chicago, Illinois 60604, (312) 886-6008,
<a href="/cdn-cgi/l/email-protection#a1c7ced2d28fcac4cdd2c4d8e1c4d1c08fc6ced7"><span class="__cf_email__" data-cfemail="e88e879b9bc6838d849b8d91a88d9889c68f879e">[email protected]</span></a>. The EPA Region 5 office is open from 8:30 a.m. to
4:30 p.m., Monday through Friday.
SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,''
``us,'' or ``our'' is used, we mean the EPA.
This supplementary information section is arranged as follows:
I. What actions is the EPA proposing?
II. Background and Requirements for Regional Haze Plans
A. Regional Haze Background
B. Roles of Agencies in Addressing Regional Haze
III. Requirements for Regional Haze Plans for the Second
Implementation Period
A. Long-Term Strategy for Regional Haze
B. Reasonable Progress Goals
C. Monitoring Strategy and Other State Implementation Plan
Requirements
D. Requirements for Periodic Reports Describing Progress Towards
the Reasonable Progress Goals
E. Requirements for State and Federal Land Manager Coordination
IV. The EPA's Evaluation of Illinois' Regional Haze Submission for
the Second Implementation Period
A. Background on Illinois' First Implementation Period SIP
Submission
B. Illinois' Second Implementation Period SIP Submission and the
EPA's Evaluation
C. Identification of Class I Areas
D. Calculations of Baseline, Current, and Natural Visibility
Conditions; Progress to Date; and the Uniform Rate of Progress
E. Long-Term Strategy for Regional Haze
1. Selection of Sources for Analysis
2. Emission Measures Necessary To Make Reasonable Progress
3. Illinois' Long-Term Strategy
4. The EPA's Evaluation of Illinois' Compliance With 40 CFR
51.308(f)(2)(i)
5. Consultation With Federal Land Managers and States
6. Five Additional Factors
F. Reasonable Progress Goals
G. Monitoring Strategy and Other Implementation Plan
Requirements
H. Requirements for Periodic Reports Describing Progress Towards
the Reasonable Progress Goals
I. Requirements for State and Federal Land Manager Coordination
V. Interstate Transport for the 2012 PM<INF>2.5</INF> and 2015 Ozone
NAAQS Infrastructure SIPs--Visibility Component
A. Background on Infrastructure SIPs
B. The EPA's Evaluation of Illinois' Infrastructure SIP
Submissions
VI. Proposed Actions
VII. Statutory and Executive Order Reviews
I. What Actions is the EPA Proposing?
On June 3, 2024, Illinois EPA submitted a revision to its SIP to
address regional haze for the second implementation period. Illinois
EPA submitted this SIP revision to satisfy the requirements of the
CAA's regional haze program pursuant to CAA section 169A and 40 CFR
51.308. The EPA proposes to find that the Illinois regional haze SIP
revision for the second implementation period meets the applicable
statutory and regulatory requirements and thus proposes to approve the
submission into Illinois' SIP.
On September 29, 2017, and May 16, 2019, Illinois EPA submitted SIP
revisions addressing infrastructure requirements for the 2012
PM<INF>2.5</INF> NAAQS and the 2015 ozone NAAQS, respectively. The EPA
proposes to approve both submissions as meeting CAA section
110(a)(2)(D)(i)(II), which requires a State's SIP to contain adequate
provisions prohibiting emissions that will interfere with required
visibility protection measures in any other State's SIP.
II. Background and Requirements for Regional Haze Plans
A detailed history and background of the regional haze program is
provided in multiple prior EPA proposal actions.\1\ For additional
background on the 2017 Regional Haze Rule (RHR) revisions, please refer
to Section III. Overview of Visibility Protection Statutory Authority,
Regulation, and Implementation of ``Protection of Visibility:
Amendments to Requirements for State Plans'' of the
[[Page 9780]]
2017 RHR.\2\ The following is an abbreviated history and background of
the regional haze program and 2017 RHR as it applies to the current
action.
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\1\ See 90 FR 13516 (March 24, 2025).
\2\ See 82 FR 3078 (January 10, 2017, located at <a href="https://www.federalregister.gov/documents/2017/01/10/2017-00268/protection-of-visibility-amendments-to-requirements-for-State-plans#h-16">https://www.federalregister.gov/documents/2017/01/10/2017-00268/protection-of-visibility-amendments-to-requirements-for-State-plans#h-16</a>).
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A. Regional Haze Background
In the 1977 CAA Amendments, Congress created a program for
protecting visibility in the nation's mandatory Class I Federal areas,
which include certain national parks and wilderness areas.\3\ CAA 169A.
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.'' CAA 169A(a)(1). Regional haze is visibility impairment
that is produced by a multitude of anthropogenic sources and activities
which are located across a broad geographic area and that emit
pollutants that impair visibility. Visibility impairing pollutants
include fine and coarse particulate matter (PM) (e.g., sulfates,
nitrates, organic carbon, elemental carbon, and soil dust) and their
precursors (e.g., sulfur dioxide (SO<INF>2</INF>), nitrogen oxides
(NO<INF>X</INF>), and, in some cases, volatile organic compounds (VOC)
and ammonia (NH<INF>3</INF>)). Fine particle precursors react in the
atmosphere to form PM<INF>2.5</INF>, which impairs visibility by
scattering and absorbing light. Visibility impairment reduces the
perception of clarity and color, as well as visible distance.\4\
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\3\ Areas statutorily 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. CAA
162(a). There are 156 mandatory Class I areas. The list of areas to
which the requirements of the visibility protection program apply is
in 40 CFR part 81, subpart D.
\4\ There are several ways to measure the amount of visibility
impairment, i.e., haze. One such measurement is the deciview, which
is the principal metric used by the RHR. Under many circumstances, a
change in one deciview will be perceived by the human eye to be the
same on both clear and hazy days. The deciview is unitless. It is
proportional to the logarithm of the atmospheric extinction of
light, which is the perceived dimming of light due to its being
scattered and absorbed as it passes through the atmosphere.
Atmospheric light extinction (b\ext\) is a metric used for
expressing visibility and is measured in inverse megameters
(Mm<SUP>-1</SUP>). The formula for the deciview is 10 ln (b\ext\)/10
Mm<SUP>-1</SUP>). 40 CFR 51.301.
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To address regional haze visibility impairment, the 1999 RHR
established an iterative planning process that requires both States in
which Class I areas are located and States ``the emissions from which
may reasonably be anticipated to cause or contribute to any impairment
of visibility'' in a Class I area to periodically submit SIP revisions
to address such impairment. CAA 169A(b)(2); \5\ see also 40 CFR
51.308(b), (f) (establishing submission dates for iterative regional
haze SIP revisions); (64 FR 35714 at 35768, July 1, 1999).
On January 10, 2017, the EPA promulgated revisions to the RHR, (82
FR 3078, January 10, 2017), that apply for the second and subsequent
implementation periods. The reasonable progress requirements as revised
in the 2017 rulemaking (referred to here as the 2017 RHR Revisions) are
codified at 40 CFR 51.308(f).
B. Roles of Agencies in Addressing Regional Haze
Because the air pollutants and pollution affecting visibility in
Class I areas can be transported over long distances, successful
implementation of the regional haze program requires long-term,
regional coordination among multiple jurisdictions and agencies that
have responsibility for Class I areas and the emissions that impact
visibility in those areas. To address regional haze, States need to
develop strategies in coordination with one another, considering the
effect of emissions from one jurisdiction on the air quality in
another. Five regional planning organizations (RPOs), which include
representation from State and Tribal governments, the EPA, and Federal
Land Managers (FLMs), were developed in the lead-up to the first
implementation period to address regional haze. RPOs evaluate technical
information to better understand how emissions from State and Tribal
land impact Class I areas across the country, pursue the development of
regional strategies to reduce emissions of particulate matter and other
pollutants leading to regional haze, and help States meet the
consultation requirements of the RHR.
The Lake Michigan Air Directors Consortium (LADCO) is an RPO that
includes the States of Illinois, Indiana, Michigan, Minnesota, Ohio,
and Wisconsin. LADCO's work is a collaborative effort of State
governments, Tribal governments, and various Federal agencies
established to initiate and coordinate activities associated with the
management of regional haze, visibility, and other air quality issues
in the Midwest. Along with the six LADCO States, participants in
LADCO's Regional Haze Technical Workgroup include the EPA, the U.S.
National Park Service (NPS), the U.S. Fish and Wildlife Service (FWS),
the U.S. Forest Service (USFS), regional Tribal air programs, and local
air agencies.
III. Requirements for Regional Haze Plans for the Second Implementation
Period
Under the CAA and the EPA's regulations, all 50 States, the
District of Columbia, and the U.S. Virgin Islands are required to
submit regional haze SIPs satisfying the applicable requirements for
the second implementation period of the regional haze program by July
31, 2021. Each State's SIP must contain a long-term strategy for making
reasonable progress toward meeting the national goal of remedying any
existing and preventing any future anthropogenic visibility impairment
in Class I areas. CAA 169A(b)(2)(B). To this end, 40 CFR 51.308(f) lays
out the process by which States determine what constitutes their long-
term strategies, with the order of the requirements in 40 CFR
51.308(f)(1) through (3) generally mirroring the order of the steps in
the reasonable progress analysis \6\ and (f)(4) through (6) containing
additional, related requirements. Broadly speaking, a State first must
identify the Class I areas within the State and determine the Class I
areas outside the State in which visibility may be affected by
emissions from the State. These are the Class I areas that must be
addressed in the State's long-term strategy. See 40 CFR 51.308(f),
(f)(2). For each Class I area within its borders, a State must then
calculate the baseline (five-year average period of 2000-2004),
current, and natural visibility conditions (i.e., visibility conditions
without anthropogenic visibility impairment) for that area, as well as
the visibility improvement made to date and the ``uniform rate of
progress'' (URP).
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\6\ The EPA explained in the 2017 RHR Revisions that we were
adopting new regulatory language in 40 CFR 51.308(f) that, unlike
the structure in 51.308(d), ``tracked the actual planning
sequence.'' (82 FR 3091, January 10, 2017).
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In developing the regulations required by CAA section 169A(b), the
EPA established the concept of the URP for each Class I area. The URP
is the linear rate of progress needed to attain natural visibility
conditions, assuming a starting point of baseline visibility conditions
in 2004 and ending with natural conditions in 2064. The URP is
determined by drawing a straight line from the measured 2000-2004
baseline conditions (in deciviews) for the 20% most impaired days at
each Class I area to the estimated natural conditions (in deciviews)
for the 20% most impaired days in 2064. From this calculation, a URP
value can be calculated for each
[[Page 9781]]
year between 2004 and 2064. This linear interpolation is used as a
tracking metric to help States assess the amount of progress they are
making towards the national visibility goal over time in each Class I
area. See 40 CFR 51.308(f)(1). The EPA developed the URP to address the
diverse concerns of Eastern and Western States and account for the
varying levels of visibility impairment in Class I areas around the
country while ensuring an equitable approach nationwide. For each Class
I area, States must calculate the URP for the end of each
implementation period (e.g., in 2028 for the second implementation
period).\7\ 40 CFR 51.308(f)(1)(vi)(A). States may also adjust the URP
to account for impacts from anthropogenic sources outside the United
States and/or impacts from certain wildland prescribed fires. 40 CFR
51.308(f)(1)(vi).
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\7\ We note that RPGs are a regulatory construct that we
developed to address the statutory mandate in CAA section
169B(e)(1), which required our regulations to include ``criteria for
measuring `reasonable progress' toward the national goal.'' Under 40
CFR 51.308(f)(3)(ii), RPGs measure the progress that is projected to
be achieved by the control measures a State has determined are
necessary to make reasonable progress. Consistent with the 1999 RHR,
the RPGs are unenforceable, though they create a benchmark that
allows for analytical comparisons to the URP and mid-implementation-
period course corrections if necessary. 82 FR 3091-3092 (January 10,
2017).
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Each State having a Class I area and/or emissions that may affect
visibility in a Class I area must then develop a long-term strategy
that includes the enforceable emission limitations, compliance
schedules, and other measures that are necessary to make reasonable
progress in such areas. A reasonable progress determination is based on
applying the four factors in CAA section 169A(g)(1) to sources of
visibility impairing pollutants that the State has selected to assess
for controls for the second implementation period. Additionally, as
further explained below, the RHR at 40 CFR 51.308(f)(2)(iv) separately
provides five ``additional factors'' \8\ that States must consider in
developing their long-term strategies. See 40 CFR 51.308(f)(2). A State
evaluates potential emission reduction measures for those selected
sources and determines which are necessary to make reasonable progress.
Those measures are then incorporated into the State's long-term
strategy. After a State has developed its long-term strategy, it then
establishes RPGs for each Class I area within its borders by modeling
the visibility impacts of all reasonable progress controls at the end
of the second implementation period, i.e., in 2028, as well as the
impacts of other requirements of the CAA. The RPGs include reasonable
progress controls not only for sources in the State in which the Class
I area is located, but also for sources in other States that contribute
to visibility impairment in that area. The RPGs are then compared to
the baseline visibility conditions and the URP to ensure that progress
is being made towards the statutory goal of preventing any future and
remedying any existing anthropogenic visibility impairment in Class I
areas. 40 CFR 51.308(f)(2)-(3). For each Class I area, States must
compare the RPG for the 20% most impaired days to the URP for the end
of the implementation period. If the RPG is above the URP, then an
additional ``robust demonstration'' requirement is triggered for each
State that contributes to that Class I area. 40 CFR 51.308(f)(3)(ii).
There are additional requirements in the rule, including FLM
consultation, that apply to all visibility protection SIPs and SIP
revisions. See e.g., 40 CFR 51.308(i).
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\8\ The five ``additional factors'' for consideration in 40 CFR
51.308(f)(2)(iv) are distinct from the four factors listed in CAA
section 169A(g)(1) and 40 CFR 51.308(f)(2)(i) that states must
consider and apply to sources in determining reasonable progress.
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A. Long-Term Strategy for Regional Haze
While States have discretion to choose any source selection
methodology that is reasonable, whatever choices they make should be
reasonably explained. To this end, 40 CFR 51.308(f)(2)(i) requires that
a State's SIP submission include ``a description of the criteria it
used to determine which sources or groups of sources it evaluated.''
The technical basis for source selection, which may include methods for
quantifying potential visibility impacts such as emissions divided by
distance metrics, trajectory analyses, residence time analyses, and/or
photochemical modeling, must also be appropriately documented, as
required by 40 CFR 51.308(f)(2)(iii).
Once a State has selected the set of sources, the next step is to
determine the emissions reduction measures for those sources that are
necessary to make reasonable progress for the second implementation
period.\9\ This is accomplished by considering the four factors--``the
costs of compliance, the time necessary for compliance, and the energy
and nonair quality environmental impacts of compliance, and the
remaining useful life of any existing source subject to such
requirements.'' CAA 169A(g)(1). The EPA has explained that the four-
factor analysis is an assessment of potential emission reduction
measures (i.e., control options) for sources; ``use of the terms
`compliance' and `subject to such requirements' in section 169A(g)(1)
strongly indicates that Congress intended the relevant determination to
be the requirements with which sources would have to comply to satisfy
the CAA's reasonable progress mandate.'' 82 FR 3078 at 3091, January
10, 2017. Thus, for each source it has selected for four-factor
analysis,\10\ a State must consider a ``meaningful set'' of technically
feasible control options for reducing emissions of visibility impairing
pollutants. Id. at 3088.
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\9\ The CAA provides that, ``[i]n determining reasonable
progress there shall be taken into consideration'' the four
statutory factors. CAA 169A(g)(1). However, in addition to four-
factor analyses for selected sources, groups of sources, or source
categories, a State may also consider additional emission reduction
measures for inclusion in its long-term strategy, e.g., from other
newly adopted, on-the-books, or on-the-way rules and measures for
sources not selected for four-factor analysis for the second
implementation period.
\10\ ``Each source'' or ``particular source'' is used here as
shorthand. While a source-specific analysis is one way of applying
the four factors, neither the statute nor the RHR requires States to
evaluate individual sources. Rather, States have ``the flexibility
to conduct four-factor analyses for specific sources, groups of
sources or even entire source categories, depending on state policy
preferences and the specific circumstances of each state.'' 82 FR
3078 at 3088, January 10, 2017.
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EPA has also explained that, in addition to the four statutory
factors, States have flexibility under the CAA and RHR to reasonably
consider visibility benefits as an additional factor alongside the four
statutory factors.\11\ Ultimately, while States have discretion to
reasonably weigh the factors and to determine what level of control is
needed, 40 CFR 51.308(f)(2)(i) provides that a State ``must include in
its implementation plan a description of . . . how the four factors
were taken into consideration in selecting the measure for inclusion in
its long-term strategy.''
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\11\ See, e.g., Responses to Comments on Protection of
Visibility: Amendments to Requirements for State Plans; Proposed
Rule (81 FR 26942, May 4, 2016) (December 2016), Docket Number EPA-
HQ-OAR-2015-0531, U.S. Environmental Protection Agency at 186.
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As explained above, 40 CFR 51.308(f)(2)(i) requires States to
determine the emission reduction measures for sources that are
necessary to make reasonable progress by considering the four factors.
Pursuant to 40 CFR 51.308(f)(2), measures that are necessary to make
reasonable progress towards the national visibility goal must be
included in a State's long-term strategy and in its SIP.\12\ If the
outcome of a four-factor analysis is that an emissions reduction
measure is necessary to make reasonable progress towards remedying
existing or preventing future anthropogenic
[[Page 9782]]
visibility impairment, that measure must be included in the SIP.
The characterization of information on each of the factors is also
subject to the documentation requirement in 40 CFR 51.308(f)(2)(iii).
The reasonable progress analysis is a technically complex exercise, and
also a flexible one that provides States with bounded discretion to
design and implement approaches appropriate to their circumstances.
Given this flexibility, 40 CFR 51.308(f)(2)(iii) plays an important
function in requiring a State to document the technical basis for its
decision making so that the public and the EPA can comprehend and
evaluate the information and analysis the State relied upon to
determine what emission reduction measures must be in place to make
reasonable progress. The technical documentation must include the
modeling, monitoring, cost, engineering, and emissions information on
which the State relied to determine the measures necessary to make
reasonable progress. Additionally, the RHR at 40 CFR 51.308(f)(2)(iv)
separately provides five ``additional factors'' \13\ that States must
consider in developing their long-term strategies: (1) Emission
reductions due to ongoing air pollution control programs, including
measures to address reasonably attributable visibility impairment; (2)
measures to reduce the impacts of construction activities; (3) source
retirement and replacement schedules; (4) basic smoke management
practices for prescribed fire used for agricultural and wildland
vegetation management purposes and smoke management programs; and (5)
the anticipated net effect on visibility due to projected changes in
point, area, and mobile source emissions over the period addressed by
the long-term strategy.
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\13\ The five ``additional factors'' for consideration in 40 CFR
51.308(f)(2)(iv) are distinct from the four factors listed in CAA
section 169A(g)(1) and 40 CFR 51.308(f)(2)(i) that States must
consider and apply to sources in determining reasonable progress.
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Because the air pollution that causes regional haze crosses State
boundaries, 40 CFR 51.308(f)(2)(ii) requires a State to consult with
other States that also have emissions that are reasonably anticipated
to contribute to visibility impairment in a given Class I area. If a
State, pursuant to consultation, agrees that certain measures (e.g., a
certain emission limitation) are necessary to make reasonable progress
at a Class I area, it must include those measures in its SIP. 40 CFR
51.308(f)(2)(ii)(A). Additionally, the RHR requires that States that
contribute to visibility impairment at the same Class I area consider
the emission reduction measures the other contributing States have
identified as being necessary to make reasonable progress for their own
sources. 40 CFR 51.308(f)(2)(ii)(B). If a State has been asked to
consider or adopt certain emission reduction measures, but ultimately
determines those measures are not necessary to make reasonable
progress, that State must document in its SIP the actions taken to
resolve the disagreement. 40 CFR 51.308(f)(2)(ii)(C). Under all
circumstances, a State must document in its SIP submission all
substantive consultations with other contributing States. 40 CFR
51.308(f)(2)(ii)(C).
B. Reasonable Progress Goals
Reasonable progress goals ``measure the progress that is projected
to be achieved by the control measures States have determined are
necessary to make reasonable progress based on a four-factor
analysis.'' 82 FR 3078 at 3091, January 10, 2017.
For the second implementation period, the RPGs are set for 2028.
Reasonable progress goals are not enforceable targets. 40 CFR
51.308(f)(3)(iii). While States are not legally obligated to achieve
the visibility conditions described in their RPGs, 40 CFR
51.308(f)(3)(i) requires that ``[t]he long-term strategy and the
reasonable progress goals must provide for an improvement in visibility
for the most impaired days since the baseline period and ensure no
degradation in visibility for the clearest days since the baseline
period.''
RPGs may also serve as a metric for assessing the amount of
progress a State is making towards the national visibility goal. To
support this approach, the RHR requires States with Class I areas to
compare the 2028 RPG for the most impaired days to the corresponding
point on the URP line (representing visibility conditions in 2028 if
visibility were to improve at a linear rate from conditions in the
baseline period of 2000-2004 to natural visibility conditions in 2064).
If the most impaired days RPG in 2028 is above the URP (i.e., if
visibility conditions are improving more slowly than the rate described
by the URP), each State that contributes to visibility impairment in
the Class I area must demonstrate, based on the four-factor analysis
required under 40 CFR 51.308(f)(2)(i), that no additional emission
reduction measures would be reasonable to include in its long-term
strategy. 40 CFR 51.308(f)(3)(ii). To this end, 40 CFR 51.308(f)(3)(ii)
requires that each State contributing to visibility impairment in a
Class I area that is projected to improve more slowly than the URP
provide ``a robust demonstration, including documenting the criteria
used to determine which sources or groups [of] sources were evaluated
and how the four factors required by paragraph (f)(2)(i) were taken
into consideration in selecting the measures for inclusion in its long-
term strategy.''
C. Monitoring Strategy and Other State Implementation Plan Requirements
Section 51.308(f)(6) requires States to have certain strategies and
elements in place for assessing and reporting on visibility. Individual
requirements under this section apply either to States with Class I
areas within their borders, States with no Class I areas but that are
reasonably anticipated to cause or contribute to visibility impairment
in any Class I area, or both. Compliance with the monitoring strategy
requirement may be met through a State's participation in the
Interagency Monitoring of Protected Visual Environments (IMPROVE)
monitoring network, which is used to measure visibility impairment
caused by air pollution at the 156 Class I areas covered by the
visibility program. 40 CFR 51.308(f)(6), (f)(6)(i), (f)(6)(iv). All
States' SIPs must provide for procedures by which monitoring data and
other information are used to determine the contribution of emissions
from within the State to regional haze visibility impairment in
affected Class I areas, as well as a statewide inventory documenting
such emissions. 40 CFR 51.308(f)(6)(ii), (iii), (v). All States' SIPs
must also provide for any other elements, including reporting,
recordkeeping, and other measures, that are necessary for States to
assess and report on visibility. 40 CFR 51.308(f)(6)(vi).
D. Requirements for Periodic Reports Describing Progress Towards the
Reasonable Progress Goals
Section 51.308(f)(5) requires a State's regional haze SIP revision
to address the requirements of paragraphs 40 CFR 51.308(g)(1) through
(5) so that the plan revision due in 2021 will serve also as a progress
report addressing the period since submission of the progress report
for the first implementation period. The regional haze progress report
requirement is designed to inform the public and the EPA about a
State's implementation of its existing long-term strategy and whether
such implementation is in fact resulting in the expected visibility
improvement. See 81 FR 26942, 26950 (May 4, 2016), (82 FR 3078 at 3119,
January 10, 2017). To this end, every State's SIP revision for the
second implementation period is required to assess changes in
visibility
[[Page 9783]]
conditions and describe the status of implementation of all measures
included in the State's long-term strategy, including best available
retrofit technology (BART) and reasonable progress emission reduction
measures from the first implementation period, and the resulting
emissions reductions. 40 CFR 51.308(g)(1) and (2).
E. Requirements for State and Federal Land Manager Coordination
CAA section 169A(d) requires that before a State holds a public
hearing on a proposed regional haze SIP revision, it must consult with
the appropriate FLM or FLMs; pursuant to that consultation, the State
must include a summary of the FLMs' conclusions and recommendations in
the notice to the public. Consistent with this statutory requirement,
the RHR also requires that States ``provide the [FLM] with an
opportunity for consultation, in person and at a point early enough in
the State's policy analyses of its long-term strategy emission
reduction obligation so that information and recommendations provided
by the [FLM] can meaningfully inform the State's decisions on the long-
term strategy.'' 40 CFR 51.308(i)(2). For the EPA to evaluate whether
FLM consultation meeting the requirements of the RHR has occurred, the
SIP submission should include documentation of the timing and content
of such consultation. The SIP revision submitted to the EPA must also
describe how the State addressed any comments provided by the FLMs. 40
CFR 51.308(i)(3). Finally, a SIP revision must provide procedures for
continuing consultation between the State and FLMs regarding the
State's visibility protection program, including development and review
of SIP revisions, five-year progress reports, and the implementation of
other programs having the potential to contribute to impairment of
visibility in Class I areas. 40 CFR 51.308(i)(4).
IV. The EPA's Evaluation of Illinois' Regional Haze Submission for the
Second Implementation Period
A. Background on Illinois' First Implementation Period SIP Submission
For the first implementation period covering the years 2007 through
2018, Illinois EPA submitted its regional haze SIP to the EPA on June
24, 2011, and the EPA approved it on May 29, 2012. See 77 FR 39943,
July 6, 2012. The requirements for regional haze SIPs for the first
implementation period are contained in 40 CFR 51.308(d) and (e).
Pursuant to 40 CFR 51.308(g), Illinois was also responsible for
submitting a five-year progress report as a SIP revision for the first
implementation period. On February 2, 2017, Illinois EPA submitted the
progress report. The EPA approved this five-year progress report as a
revision to the Illinois SIP at 40 CFR 52.720(e) on April 3, 2018. See
83 FR 15744, April 12, 2018.
B. Illinois' Second Implementation Period SIP Submission and the EPA's
Evaluation
In accordance with section 169A of the CAA and the RHR at 40 CFR
51.308(f), Illinois EPA submitted a revision to the Illinois SIP on
June 3, 2024, to address its regional haze obligations for the second
implementation period, which runs through 2028.\14\ In developing its
2024 SIP revision, Illinois EPA initiated an FLM consultation process
and provided a public comment period for the second implementation
period. The public comment period on the 2024 SIP revision ran from
January 19, 2024, through March 21, 2024, and a public hearing was held
on February 27, 2024. Illinois EPA received and responded to comments
from FLMs and the public. Illinois EPA summarized and responded to the
FLMs' comments in appendix H to the 2024 SIP submission. Illinois EPA
included the public comments and its responses in attachments 3 and 4
to the 2024 SIP submission.
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\14\ Since Illinois did not submit a complete SIP revision by
the July 31, 2021, due date in the RHR, the EPA issued a finding of
failure to submit on August 29, 2022. See 87 FR 52856, August 30,
2022.
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Prior to submitting its 2024 regional haze SIP revision and during
the second implementation period, Illinois adopted amendments to its
Multi-Pollutant Standards (MPS) Rule on August 22, 2019,\15\ and
submitted the amended MPS Rule to the EPA as a revision to its regional
haze SIP on January 23, 2020. The EPA approved the revision on June 14,
2021, and revised Illinois' SIP at 40 CFR 52.720(c). 86 FR 13260, March
8, 2021, and 86 FR 33527, June 25, 2021. The MPS Rule established
fleet-wide SO<INF>2</INF> and NO<INF>X</INF> emission limits for
electric generating units (EGUs) and fulfilled the BART requirements of
the first implementation period. The provisions of the MPS Rule are
further described in section IV of Illinois' 2024 SIP submission and in
section 2.1 of the EPA's November 12, 2025, Technical Support Document
(TSD) for this proposed rulemaking, which is included in the docket.
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\15\ See Illinois Pollution Control Board, In the Matter of:
Amendments to 35 Ill. Adm. Code 225.233, Multi-Pollutant Standard
(MPS), R18-20, Adopted Rule, Final Order, August 22, 2019. <a href="https://pcb.illinois.gov/documents/dsweb/Get/Document-100916">https://pcb.illinois.gov/documents/dsweb/Get/Document-100916</a>.
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The following sections describe Illinois' 2024 SIP submission,
including Illinois EPA's assessment of progress made since the first
implementation period in reducing emissions of visibility impairing
pollutants and of the visibility improvement progress at nearby Class I
areas. This notice of proposed rulemaking also contains the EPA's
evaluation of Illinois' 2024 SIP submission against the requirements of
the CAA and the RHR for the second implementation period of the
regional haze program.
C. Identification of Class I Areas
Section 169A(b)(2) of the CAA requires each State in which any
Class I area is located or ``the emissions from which may reasonably be
anticipated to cause or contribute to any impairment of visibility'' in
a Class I area to have a plan for making reasonable progress toward the
national visibility goal. The RHR implements this statutory requirement
at 40 CFR 51.308(f), which provides that each State's plan ``must
address regional haze in each mandatory Class I Federal area located
within the State and in each mandatory Class I Federal area located
outside the State that may be affected by emissions from within the
State,'' and (f)(2), which requires each State's plan to include a
long-term strategy that addresses regional haze in such Class I areas.
The EPA concluded in the 1999 RHR that ``all [s]tates contain
sources whose emissions are reasonably anticipated to contribute to
regional haze in a Class I area,'' 64 FR 35714 at 35721, July 1, 1999,
and this determination was not changed in the 2017 RHR. Critically, the
statute and regulation both require that the cause-or-contribute
assessment consider all emissions of visibility impairing pollutants
from a State, as opposed to emissions of a particular pollutant or
emissions from a certain set of sources.
Illinois has no Class I areas within its borders that are among the
156 mandatory Class I Federal areas where the EPA deemed visibility to
be an important value. See 40 CFR part 81, subpart D. Thus, Illinois
EPA only evaluated the State's impact on out-of-State mandatory Class I
Federal areas covered under the RHR.
Illinois EPA is a member of LADCO and participated in the
development of LADCO's strategy for making reasonable progress towards
the national visibility goal in the Class I areas. To identify Class I
areas where progress toward natural visibility conditions may be
impacted by emissions from sources in
[[Page 9784]]
Illinois, Illinois EPA reviewed technical analyses conducted by LADCO.
This included the technical analyses from the first implementation
period compiled in 2007 by LADCO, known as the Midwest RPO at the time,
to determine which Class I areas outside the State were affected by
emission sources in Illinois.\16\ These analyses included LADCO's back
trajectory analysis and Comprehensive Air Quality Model with extensions
and its Particulate Matter Source Apportionment Tool (CAMx-PSAT) as
well as MANE-VU's contribution assessment,\17\ Missouri-Arkansas'
Contribution Assessment, VISTAS' Areas of Influence Analysis,\18\ and
WRAP's back trajectories and modeling.\19\ Using LADCO's back
trajectory analysis, LADCO initially assumed a State affected
visibility impairment in a Class I area if it was projected to
contribute two percent or more to the total light extinction. This
threshold accounted for about 90-95 percent of the total light
extinction at the Class I areas. Based on analyses conducted by other
RPOs, LADCO gave deference to the criteria established by each RPO to
identify additional Class I areas affected by LADCO States.
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\16\ The Midwest RPO's ``Draft List of Class I Areas Located
Within (or Impacted by) Midwest RPO States,'' June 26, 2007 was
included as attachment 1, appendix A of the Illinois' regional haze
SIP for the first implementation period submitted to the EPA on June
24, 2011, and is contained in the docket for the rulemaking where
the EPA approved the SIP on May 29, 2012: EPA-R05-OAR-2011-0598.
\17\ The Mid-Atlantic/Northeast Visibility Union (MANE-VU) is
the RPO for the Northeastern and Mid-Atlantic States and Tribal
governments, which include Connecticut, Delaware, the District of
Columbia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey,
New York, Pennsylvania, Penobscot Indian Nation, Rhode Island, St.
Regis Mohawk Tribe, and Vermont.
\18\ Metro 4/SESARM/VISTAS refers to the Southeastern States Air
Resources Managers, Inc. (SESARM) and the Visibility Improvement
State and Tribal Association of the Southeast (VISTAS) as the RPO
for Alabama, Florida, Georgia, Kentucky, Mississippi, North
Carolina, South Carolina, Tennesse, Virginia, West Virginia, the
Eastern Band of Cherokee Indians, and Knox County, Tennessee
(representing the 17 Southeastern local air agencies).
\19\ The Western Regional Air Partnership (WRAP) is the RPO for
Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon,
Utah, and Wyoming.
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For the second regional haze implementation period, Illinois EPA
reviewed later analyses by LADCO that also used CAMx-PSAT.\20\ In its
2017 analyses, LADCO tagged States and regions as well as individual
point sources and inventory source groups to apportion emissions to
States and regions. LADCO assessed relative visibility impacts in 2028
by projecting representative emissions inventories and known emission
controls from 2016. In 2017, a group of RPOs, States, and the EPA
established 2016 as the base year for a national air quality modeling
platform for future ozone, PM<INF>2.5</INF>, and regional haze SIP
development because that year had typical ozone and wildfire
conditions.\21\ LADCO relied upon the EPA's inventory estimates for
2016 and 2028 for most emission sectors as described in the EPA's
September 19, 2019, ``Availability of Modeling Data and Associated
Technical Support Document for the EPA's Updated 2028 Visibility Air
Quality Modeling,'' (EPA's Updated 2028 Visibility Air Quality Modeling
TSD).\22\ For EGU emissions, LADCO used forecasts from the Eastern
Regional Technical Advisory Committee (ERTAC) based on continuous
emissions monitoring data from 2016 instead of the Integrated Planning
Model used in the EPA's 2016 modeling platform. LADCO also incorporated
State-reported changes to EGUs received through September 2020 to
estimate 2028 EGU emissions.
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\20\ See appendix B of Illinois 2024 SIP submission. Details of
the analysis and source-apportioned visibility contributions at
Class I areas for regional haze second implementation period are
documented in LADCO's ``Modeling and Analysis for Demonstrating
Reasonable Progress for the Regional Haze Rule 2018-2028 Planning
Period: Technical Support Document,'' June 17, 2021.
\21\ See ``Base Year Selection Workgroup Final Report,''
produced by the Inventory Collaborative Base Year Selection
Workgroup, April 5, 2017, available at <a href="https://drive.google.com/file/d/1o0e75dIliyjDZOmBDOPxIdMUhUTeph4Y/view">https://drive.google.com/file/d/1o0e75dIliyjDZOmBDOPxIdMUhUTeph4Y/view</a> and included in the
Docket EPA-R05-OAR-2024-0261 associated with this proposed
rulemaking.
\22\ EPA, Office of Air Quality Planning and Standards,
``Availability of Modeling Data and Associate Technical Support
Document for EPA's Updated 2028 Visibility Air Quality Modeling,''
September 19, 2019, available at <a href="https://www.epa.gov/sites/default/files/2019-10/documents/updated_2028_regional_haze_modeling-tsd-2019_0.pdf">https://www.epa.gov/sites/default/files/2019-10/documents/updated_2028_regional_haze_modeling-tsd-2019_0.pdf</a> and included in the docket for this proposed rulemaking.
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Based on LADCO's 2007 and 2017 analyses,\23\ Illinois EPA used the
list of sources from the first implementation period to identify 16
Class I areas affected by emission sources in Illinois in the second
implementation period. These Class I areas are: Boundary Waters Canoe
Area Wilderness, Brigantine Wilderness Area, Caney Creek Wilderness
Area, Great Gulf Wilderness Area, Great Smoky Mountains National Park,
Hercules-Glades Wilderness Area, Isle Royale National Park, Lye Brook
Wilderness, Acadia National Park, Mammoth Cave National Park, Mingo
Wilderness Area, Moosehorn Wilderness Area, Seney Wilderness Area,
Sipsey Wilderness Area, Upper Buffalo Wilderness Area, and Voyageurs
National Park.\24\ Illinois EPA characterized the list as conservative
because emissions of visibility-impairing pollutants from sources in
Illinois have declined since the first implementation period. 2028
visibility conditions at these Class I areas are projected by both
LADCO and the EPA to be below the adjusted and unadjusted URP
glidepaths provided in the EPA's Updated 2028 Visibility Air Quality
Modeling TSD. These projections are depicted in Table 3.1 of Illinois'
SIP submission and Table 8 of the EPA's November 12, 2025, TSD.
Illinois EPA notes that the 2028 projections do not account for the
2019 revisions to the MPS, many emission reductions that have already
taken place during the second implementation period, or all elements of
Illinois' long-term strategy. As such, Illinois EPA anticipates greater
improvements in visibility than those modeled in the projections by the
EPA and LADCO.
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\23\ See appendix B of Illinois 2024 regional haze SIP
submission for LADCO's technical support document and supporting
materials.
\24\ A list of Class I areas impacted by Illinois and an
accompanying map are found in section I of Illinois' 2024 SIP
submission. Tables 3.1 and 4.1 of Illinois' 2024 SIP submission
provide 2028 visibility projections for these areas based on
modeling by LADCO and the EPA.
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D. Calculations of Baseline, Current, and Natural Visibility
Conditions; Progress to Date; and the Uniform Rate of Progress
Section 51.308(f)(1) requires States to determine the following for
``each mandatory Class I Federal area located within the State'':
baseline visibility conditions for the most impaired and clearest days,
natural visibility conditions for the most impaired and clearest days,
progress to date for the most impaired and clearest days, the
differences between current visibility conditions and natural
visibility conditions, and the URP. This section also provides the
option for States to propose adjustments to the URP line for a Class I
area to account for visibility impacts from anthropogenic sources
outside the United States and/or the impacts from wildland prescribed
fires that were conducted for certain, specified objectives. 40 CFR
51.308(f)(1)(vi)(B).
Illinois has no mandatory Class I areas within its borders to which
the requirements of the visibility protection program apply in 40 CFR
part 81, subpart D. Therefore, 40 CFR 51.308(f)(1) and its requirements
do not apply.
E. Long-Term Strategy for Regional Haze
Each State having a Class I area within its borders or emissions
that may affect visibility in a Class I area must
[[Page 9785]]
develop a long-term strategy for making reasonable progress towards the
national visibility goal. CAA 169A(b)(2)(B). After considering the four
statutory factors, all measures that are determined to be necessary to
make reasonable progress must be in the long-term strategy. In
developing its long-term strategies, a State must also consider the
five additional factors in 40 CFR 51.308(f)(2)(iv). As part of its
reasonable progress determinations, the State must describe the
criteria used to determine which sources or group of sources were
evaluated (i.e., subjected to four-factor analysis) for the second
implementation period and how the four factors were taken into
consideration in selecting the emission reduction measures for
inclusion in the long-term strategy. 40 CFR 51.308(f)(2)(iii).
1. Selection of Sources for Analysis
The provisions of 40 CFR 51.308(f)(2)(i) require States to describe
the criteria used to determine which sources or groups of sources that
State evaluated for potential emission reduction measures. States may
rely on technical information developed by the RPOs of which they are
members to select sources for four-factor analysis and to conduct that
analysis, as well as to satisfy the documentation requirements under 40
CFR 51.308(f).
Illinois EPA described its source selection process in section IV
of the 2024 SIP submission. In selecting sources to evaluate for
potential control measure additions during the second implementation
period, Illinois EPA considered SO<INF>2</INF>, NO<INF>X</INF>, VOC,
NH<INF>3</INF>, and direct PM emissions but focused on NO<INF>X</INF>
and SO<INF>2</INF> emissions following an analysis of IMPROVE data
performed by LADCO. This analysis, described in LADCO's Technical
Support Document ``Modeling and Analysis for Demonstrating Reasonable
Progress for the Regional Haze Rule 2018-2028 Planning Period,''
(LADCO's 2021 TSD),\25\ dated June 17, 2021, demonstrated that ammonium
sulfate and ammonium nitrate are the largest components of haze during
the most impaired days at the LADCO Class I areas. The LADCO Class I
areas consist of Boundary Waters Canoe Area Wilderness and Voyageurs
National Park in Minnesota and Isle Royale National Park and Seney
Wilderness Area in Michigan. As precursors to ammonium sulfate and
ammonium nitrate particulates, SO<INF>2</INF>, and NO<INF>X</INF>, and
NH<INF>3</INF> emissions contribute more to visibility impairment in
the LADCO Class I Areas than direct PM<INF>2.5</INF> and VOC emissions.
Illinois EPA determined that focusing on potential reductions in
NO<INF>X</INF> and SO<INF>2</INF> emissions would be the most effective
approach for the second implementation period. The EPA finds this
approach to be reasonable, as noted in the ``Guidance on Regional Haze
State Implementation Plans for the Second Implementation Period,'' EPA
Office of Air Quality Planning and Standards, Research Triangle Park,
August 20, 2019 (``2019 Regional Haze Guidance'') at page 12.\26\
Illinois decided to focus specifically on NO<INF>X</INF> and
SO<INF>2</INF> emissions from point sources based on information in the
EPA's Updated 2028 Visibility Air Quality Modeling TSD, which provided
a percentage breakdown of contributions to Class I areas by source
sectors, such as point EGU point, non-EGU, nonpoint point, onroad, oil
and gas, residential wood combustion, and anthropogenic dust. Table 4.1
of Illinois' 2024 SIP submission includes the percentage contributions
to Class I areas affected by Illinois. The EGU and non-EGU point source
sector emissions contribute the largest percentage, an average of 56
percent, of the visibility impairment in the Class I areas affected by
Illinois. The EPA finds that Illinois EPA's decision to focus on
NO<INF>X</INF> and SO<INF>2</INF> emissions from point sources is
further supported by Tables 4-2 and 4-7 of LADCO's 2021 TSD, which show
that emissions from point sources account for a large portion of both
NO<INF>X</INF> and SO<INF>2</INF> emissions in Illinois, whereas
NH<INF>3</INF>, the third precursor to ammonium nitrate and ammonium
sulfate, is mostly emitted from nonpoint sources.
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\25\ LADCO's 2021 TSD is contained in appendix B of Illinois'
2024 regional haze SIP submission.
\26\ The EPA's 2019 Regional Haze Guidance is available at
<a href="https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period">https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period</a> and is included in
the docket for this proposed rulemaking.
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Illinois EPA selected point sources for potential four-factor
analyses based on LADCO's analyses of National Emissions Inventory
(NEI) data. LADCO generated source lists based on total process-level
emissions of NO<INF>X</INF>, SO<INF>2</INF>, PM<INF>2.5</INF>, and
NH<INF>3</INF> (Q) divided by distance (d) to the center of the nearest
Class I area, where Q/d was used as a surrogate quantitative metric of
visibility impact in lieu of air quality modeling. The National
Emissions Inventory Collaborative 2016 alpha inventory was selected in
2018 by the LADCO Regional Haze Technical Workgroup for the Q/d
analysis as the best available inventory at that time. In support of
using the 2016 data, Illinois EPA confirmed that there have been no
emissions increases large enough to make use of the 2016 data
inappropriate, especially since 2014-2020 NEI data demonstrates
decreasing trends in NO<INF>X</INF>, PM<INF>2.5</INF>, and
SO<INF>2</INF> emissions.\27\ For details on the data and methods used
in the Q/d analysis, see LADCO's October 14, 2020, technical memorandum
``Description of the Sources and Methods Used to Support Q/d Analysis
for the 2nd Regional Haze Planning Period'' \28\ and section 5 of
LADCO's 2021 TSD.
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\27\ See Tables 11.5 to 11.7 of Illinois' 2024 SIP submission.
\28\ LADCO's October 14, 2020, technical memorandum
``Description of the Sources and Methods Used to Support Q/d
Analysis for the 2nd Regional Haze Planning Period'' contains a
weblink to the spreadsheets and emissions data files used for the Q/
d analysis and is publicly available in the docket for this proposed
rulemaking and on LADCO's website at <a href="https://www.ladco.org/wp-content/uploads/Projects/Regional-Haze/Round2/LADCO_QoverD_Memo_16Oct2020.pdf">https://www.ladco.org/wp-content/uploads/Projects/Regional-Haze/Round2/LADCO_QoverD_Memo_16Oct2020.pdf</a>.
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Illinois EPA designed its source selection methodology to capture a
meaningful portion of Illinois' total contribution to visibility
impairment in the Class I areas, including the largest sources in the
State. Illinois EPA initially set a unit-level Q/d threshold of four to
begin identifying point source emission units for potentially cost-
effective control additions, where Q reflected LADCO's 2028 projections
from the 2016 base year sum of NO<INF>X</INF>, SO<INF>2</INF>,
PM<INF>2.5</INF>, and NH<INF>3</INF> emissions. To focus on sources
with the greatest visibility impact, Illinois EPA then grouped those
units by source and identified units with Q/d greater than four at
facilities with Q/d greater than 10 for potential four-factor analyses.
This resulted in a list of 30 units, accounting for 71.4 percent of all
emissions of SO<INF>2</INF>, NO<INF>X</INF>, NH<INF>3</INF>, and
PM<INF>2.5</INF> from units with Q/d greater than one in Illinois,
including all the largest sources. Of these 30 units, 14 are no longer
operating:
<bullet> Electric Energy Inc.--Joppa, Units 1, 2, 3, 4, 5, and 6
<bullet> Dynegy Midwest Generation LLC--Baldwin, Unit 13
<bullet> Southern Illinois Power Cooperative--Marion, Unit 4
<bullet> Illinois Power Resources Generating LLC--Edwards, Units 3 and
4
<bullet> Illinois Power Generating Co.--Newton, Unit 13
<bullet> Dynegy Midwest Generation LLC--Wood River, Unit 1
<bullet> Will County Generating Station--Romeoville, Unit 16
<bullet> Pacific Ethanol Pekin Inc., Unit 19 \29\
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\29\ Pacific Ethanol Pekin Inc. is now Alto Pekin, LLC.
Illinois EPA then determined that the existing controls on the
following seven units are effective to the extent that a full four-
factor analysis would likely
[[Page 9786]]
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result in a conclusion that no further controls are necessary.
<bullet> Dynegy Midwest Generation LLC--Baldwin, Units 1 and 2
<bullet> Illinois Power Generating Co.--Newton, Unit 3
<bullet> Midwest Generation LLC--Powerton, Units 29 and 31
<bullet> Kincaid Generation LLC, Units 8 and 9
Illinois EPA then selected the remaining nine units for four-factor
analyses:
<bullet> Prairie State Generating Station--Marissa, Units 4 and 5
<bullet> Southern Illinois Power Cooperative--Marion, Unit 123
<bullet> Rain CII Carbon LLC--Robinson, Units 1 and 2
<bullet> Lafarge Midwest Inc.--Grand Chain, Units 47 and 66 \30\
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\30\ Lafarge Midwest Inc.--Grand Chain is now Holcim US, Inc.--
Joppa Plant, Grand Chain.
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<bullet> Archer Daniels Midland Co.--Decatur, Units 222 and 230
The demonstrations of existing effective controls and four-factor
analyses are addressed under sections IV.E.2 and IV.E.4 of this
preamble. Further details on Illinois EPA's source selection process,
past retirements, demonstrations of existing effective controls, and
four factor analyses are addressed in sections III, IV, V, and VI and
appendix A of Illinois' 2024 SIP submission and sections 2 and 3 of the
EPA's November 12, 2025, TSD.
2. Emission Measures Necessary To Make Reasonable Progress
The provisions of 40 CFR 51.308(f)(2)(i) require States to evaluate
and determine the emission reduction measures that are necessary to
make reasonable progress by applying the four statutory factors to
sources in a control analysis. The emission reduction measures that are
necessary to make reasonable progress must be included in the long-term
strategy. 40 CFR 51.308(f)(2).
As mentioned above, Illinois EPA demonstrated that the seven units
at Baldwin, Newton, Powerton, and Kincaid have existing effective
control measures. Illinois EPA cited requirements contained in the MPS,
the Combined Pollutant Standards (CPS),\31\ and permits as well as
2016-2022 annual NO<INF>X</INF> and SO<INF>2</INF> emissions data to
show that each unit has consistently implemented its existing measures
and has achieved reasonably consistent annual emission rates that are
not projected to increase in the future. For Baldwin, Newton, and
Powerton, Illinois found that the existing measures under the MPS and
CPS are necessary for reasonable progress for the second implementation
period and documented that they form a part of the long-term strategy,
are already federally enforceable and permanent, and are already
included in the regulatory portion of Illinois' SIP at 40 CFR 52.720.
For Kincaid, Illinois EPA referred to the existing BART measures that
were previously included in the long-term strategy developed in the
first implementation period. See 77 FR 3966, January 26, 2012. As such,
Illinois EPA determined that additional control measures for the seven
units at Baldwin, Newton, Powerton, and Kincaid are not necessary to
make reasonable progress in the second implementation period. Illinois
EPA's demonstrations of existing effective controls for these units are
further described in section 3.3 of the EPA's November 12, 2025, TSD.
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\31\ The CPS are described in section IV of Illinois' 2024
regional haze SIP submission and in section 2.2 of the EPA's
November 12, 2025, TSD.
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For the nine units at Prairie State, Marion, Rain CII Carbon,
Lafarge Midwest, and Archer Daniels Midland, Illinois EPA provided a
four-factor analysis as summarized in section V of Illinois' 2024 SIP
submission and section 4 of the EPA's November 12, 2025, TSD. Appendix
A to Illinois' submission describes the four-factor analyses in detail.
Each analysis considered all four statutory factors and appropriately
followed the methods in the EPA Air Pollution Control Cost Manual.\32\
As presented in Table 1, Illinois EPA documented the range of cost
effectiveness of potential new controls that were determined to be
technically feasible.
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\32\ See the EPA's Air Pollution Control Cost Manual, available
at <a href="https://www.epa.gov/economic-and-cost-analysis-air-pollution-regulations/cost-reports-and-guidance-air-pollution">https://www.epa.gov/economic-and-cost-analysis-air-pollution-regulations/cost-reports-and-guidance-air-pollution</a> and included in
the docket for this proposed rulemaking.
Table 1--Estimated Cost Effectiveness of Feasible Control Options Evaluated
----------------------------------------------------------------------------------------------------------------
Facility Unit Control option Cost effectiveness (2020 dollars)
----------------------------------------------------------------------------------------------------------------
Prairie State Generating Station Boilers 1 and 2........ Integrated $17,219 per ton of both SO2 and
Gasification NOX to remove 298.3 tons of NOX
Combined Cycle and 11,669 tons of SO2 per year
(IGCC).
Southern Illinois Power Boiler 123............. Fuel switch....... $3,802 per ton of both SO2 and
Cooperative. NOX to remove 143.9 tons of NOX
and 1,712 tons of SO2 per year.
IGCC.............. $8,395.90 per ton of both SO2 and
NOX to remove 108.89 tons of NOX
and 2017.69 tons of SO2 per
year.
Rain CII Carbon LLC............. Kilns 1 and 2.......... Selective Non- $3,395 per ton of NOX.
Catalytic
Reduction (SNCR).
Selective $7,701 per ton of NOX.
Catalytic
Reduction (SCR).
Semi-dry Flue Gas $9,570 per ton of SO2.
Desulfurization
(FGD).
Wet FGD........... $29,106 per ton of SO2.
Holcim US Inc................... Kiln 1................. SNCR.............. $1,762 per ton of NOX for minimal
or no NOX reductions.
Regenerative SCR.. $6,042 per ton of NOX for minimal
or no NOX reductions.
SCR upgrade....... $659-$19,445 per ton of NOX to
remove a maximum of 147 tons of
NOX per year.
Dry FGD........... $2,527-$97,556 per ton of SO2.
Semi-dry FGD...... $2,637-$51,744 per ton of SO2.
Wet FGD........... $1,648-$86,570 per ton of SO2.
Archer Daniels Midland Co....... Boilers 1-9............ SCR............... $4,962-$7,252 per ton of NOX.
IGCC.............. $70,878 per ton of both NOX and
SO2.
Spray Dryer $5,844-$8,010 per ton of SO2; SO2
Absorber-FGD. reductions unlikely.
Wet FGD........... $6,353-$8,930 per ton of SO2; SO2
reductions unlikely.
----------------------------------------------------------------------------------------------------------------
For each unit, Illinois EPA determined that additional control
measures are not necessary to make reasonable progress in the second
implementation period and that pursuing additional emission reductions
[[Page 9787]]
through new emission control equipment or emissions limitations is not
cost-effective. Illinois EPA determined this based on the units'
existing controls, the cost of the alternative control measures, and
the remaining useful life of the units. Illinois EPA also concluded
that the existing emission control measures for each of these units are
not necessary for reasonable progress for the second implementation
period and do not need to be included in the regulatory portion of the
SIP beyond where they are already included. Illinois EPA determined
this based on the limits in the sources' air permits, historical data
showing relatively consistent or declining NO<INF>X</INF> and
SO<INF>2</INF> annual emissions, recent unit emission rates, and the
2028 projections of overall emissions showing that emissions are not
expected to increase in the future.
3. Illinois' Long-Term Strategy
Each State's long-term strategy must include the enforceable
emission limitations, compliance schedules, and other measures that are
necessary to make reasonable progress. 40 CFR 51.308(f)(2). After
considering information regarding existing effective controls, the four
statutory factors in 40 CFR 51.308(f)(2)(i), and the five additional
factors in 40 CFR 51.308(f)(2)(iv) in addition to other requirements in
40 CFR 51.308(f)(2)(ii) described below, Illinois EPA developed its
long-term strategy for the second implementation period. Illinois EPA's
long-term strategy is provided in section VI of Illinois' 2024 SIP
submission and lists, at the State's discretion, measures beyond what
the State deemed necessary for reasonable progress. Illinois EPA's
long-term strategy lists State regulations such as the NO<INF>X</INF>
Reasonably Available Control Technology (RACT) standards \33\ as well
as State regulations that are included in the regulatory part of
Illinois' SIP at 40 CFR 52.720 for the MPS,\34\ CPS,\35\ and emission
standards and limitations for Stationary Reciprocating Internal
Combustion Engines (RICE) and Turbines.\36\ Additionally, Illinois
EPA's long-term strategy lists Federal measures for point sources
including the Revised Cross-State Air Pollution Rule Update,\37\ New
Source Performance Standards (NSPS),\38\ and National Emission
Standards for Hazardous Air Pollutants (NESHAP),\39\ as well as several
Federal measures for area sources and on-road and non-road mobile
sources. Of all the measures in the list, Illinois EPA only specified
the State regulations for the MPS, CPS, and Stationary RICE and
Turbines as necessary for reasonable progress in the second
implementation period and reiterated that those measures are part of
Illinois' SIP under 40 CFR 52.720, thus already federally enforceable
and permanent. Illinois EPA did not identify any additional control
requirements necessary for reasonable progress or any additional
measures to be incorporated by reference into the regulatory portion of
Illinois' SIP.
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\33\ See 35 Illinois Administrative Code 217.
\34\ See 86 FR 33527, June 25, 2021.
\35\ See 83 FR 8612, February 28, 2018.
\36\ See 74 FR 30466, June 26, 2009.
\37\ See 40 CFR 97, subpart GGGGG.
\38\ 40 CFR 60.
\39\ 40 CFR 63.
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4. The EPA's Evaluation of Illinois' Compliance With 40 CFR
51.308(f)(2)(i)
The EPA proposes to find that Illinois has satisfied the
requirements of 40 CFR 51.308(f)(2)(i) related to evaluating sources
and determining the emission reduction measures that are necessary to
make reasonable progress by considering the four statutory factors. The
EPA is basing this proposed finding on the State's examination of its
largest sources as described above. The State considered the four
statutory factors, the historical emissions data, the emission
reductions that have already taken place during the second
implementation period, and the current control measures. As summarized
above and further described in the EPA's November 12, 2025, TSD,
Illinois' selection of sources and evaluation of control measures was
reasonable and consistent with the requirements of 40 CFR
51.308(f)(2)(i).
In addition, as recently announced and applied in the approval of
the West Virginia regional haze SIP submittal,\40\ it is the EPA's
policy that, where visibility conditions for a Class I area impacted by
a State are below the URP and the State has considered the four
statutory factors, the State will have presumptively demonstrated
reasonable progress for the second implementation period for that Class
I area. The EPA has the discretion and authority to change policy. In
FCC v. Fox Television Stations, Inc., the U.S. Supreme Court plainly
stated that an agency is free to change a prior policy and ``need not
demonstrate . . . that the reasons for the new policy are better than
the reasons for the old one; it suffices that the new policy is
permissible under the statute, that there are good reasons for it, and
that the agency believes it to be better.'' 566 U.S. 502, 515 (2009)
(referencing Motor Vehicle Mfrs. Ass'n of United States, Inc. v. State
Farm Mut. Auto. Ins. Co., 463 U.S. 29 (1983)). See also Perez v.
Mortgage Bankers Assn., 135 S. Ct. 1199 (2015). The EPA believes that
its recently adopted policy aligns with the purpose of the statute and
RHR, which is achieving ``reasonable'' progress, not maximal progress,
toward Congress' natural visibility goal.
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\40\ 90 FR 16478, 16483, April 18, 2025, and 90 FR 29737, 29738-
29740, July 7, 2025.
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In the 2017 RHR Revisions, the EPA addressed the role of the URP as
it relates to a State's development of its second implementation period
SIP. 82 FR 3078 (January 10, 2017). Specifically, in response to
comments suggesting that the URP should be considered a ``safe harbor''
that relieve States of any obligation to consider the four statutory
factors, the EPA explained that the URP was not intended to be such a
safe harbor. Id. at 3099. ``Some commenters stated a desire for
corresponding rule text dealing with situations where RPGs are equal to
(``on'') or better than (``below'') the URP or glidepath. Several
commenters stated that the URP or glidepath should be a `safe harbor,'
opining that States should be permitted to analyze whether projected
visibility conditions for the end of the implementation period will be
on or below the glidepath based on on-the-books or on-the-way control
measures, and that in such cases a four-factor analysis should not be
required.'' Id.
Other 2017 RHR comments indicated a similar approach, such as ``a
somewhat narrower entrance to a `safe harbor,' '' by suggesting that if
current visibility conditions are already below the end-of-planning-
period point on the URP line, a four-factor analysis should not be
required.'' Id. The EPA stated in its response that we did not agree
with either of these recommendations. ``The CAA requires that each SIP
revision contain long-term strategies for making reasonable progress,
and that in determining reasonable progress states must consider the
four statutory factors. Treating the URP as a safe harbor would be
inconsistent with the statutory requirement that states assess the
potential to make further reasonable progress towards natural
visibility goal in every implementation period.'' Id.
However, so long as a State considers the four factors, the
presumption that a Class I area below the URP is achieving reasonable
progress is consistent with the CAA and RHR. Indeed, we believe this
policy also recognizes the considerable improvements in visibility
impairment that have been made by a wide variety of State and Federal
programs in recent decades. In sum, Illinois EPA selected a number of
[[Page 9788]]
sources, evaluated emissions control measures, and considered the four
statutory factors. In addition, as discussed in section 6 of the EPA's
November 12, 2025, TSD, visibility conditions at all Class I areas to
which Illinois contributes are below the URP. In light of these facts,
this policy also supports the EPA's proposed finding that Illinois
reasonably concluded that no additional measures are necessary to
achieve reasonable progress during the second implementation period.
5. Consultation With Federal Land Managers and States
The consultation requirements of 40 CFR 51.308(f)(2)(ii) provide
that States must consult with other States that are reasonably
anticipated to contribute to visibility impairment in a Class I area to
develop coordinated emission management strategies containing the
emission reductions measures that are necessary to make reasonable
progress. Section 51.308(f)(2)(ii)(A) and (B) require States to
consider the emission reduction measures identified by other States as
necessary for reasonable progress and to include agreed upon measures
in their SIPs, respectively. Section 51.308(f)(2)(ii)(C) speaks to what
happens if States cannot agree on what measures are necessary to make
reasonable progress. States may also satisfy the requirement of 40 CFR
51.308(f)(2)(ii) to engage in interstate consultation with other States
that have emissions that are reasonably anticipated to contribute to
visibility impairment in a given Class I area under the auspices of
intra- and inter-RPO engagement.
Although Illinois has no mandatory Class I Federal areas within its
borders, emissions from sources within Illinois influence visibility at
mandatory Class I Federal areas. Through intra- and inter-RPO
engagement, Illinois EPA consulted with other States to develop a
coordinated emission management approach to its regional haze SIP and
to address Illinois' impact on nearby Class I areas. Consultation
within LADCO and between LADCO and neighboring RPOs, including CenSARA
\41\ and VISTAS,\42\ developed the technical information needed for
such coordinated strategies. Inter-RPO cooperation is evident in
LADCO's 2021 TSD and accompanying electronic docket,\43\ which include
area of influence modeling contributed by CenSARA and analyses for all
Class I areas performed by LADCO.
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\41\ Central States Air Resource Agencies (CenSARA) is the RPO
for the State and local governments of Arkansas, Iowa, Kansas,
Louisiana, Missouri, Nebraska, Oklahoma, and Texas.
\42\ Visibility Improvement State and Tribal Association of the
Southeast (VISTAS) is the RPO for the Southeastern State, Tribal,
and local governments, which include Alabama, Florida, Georgia,
Kentucky, Mississippi, North Carolina, South Carolina, Tennessee,
Virginia, West Virginia, the Eastern Band of Cherokee Indians, and
Knox County, Tennessee.
\43\ LADCO's electronic docket for its 2021 TSD is posted
beneath the TSD documents at <a href="https://www.ladco.org/reports/technical-support/ladco-regional-haze-tsd-second-implementation-period/">https://www.ladco.org/reports/technical-support/ladco-regional-haze-tsd-second-implementation-period/</a>. The ``2016-based 2028 glidepaths and PSAT tracer
contributions'' spreadsheet includes summaries of LADCO's 2016-based
modeling for all Class I areas. A pdf version of this spreadsheet is
included in the docket.
\43\ See Figure 2-7 of LADCO's 2021 TSD.
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Illinois EPA also received and responded to requests from MANE-
VU,\44\ Arkansas,\45\ and Missouri \46\ regarding regional haze. MANE-
VU requested that Illinois ensure emission controls be operated year-
round on certain EGUs and that Illinois pursue an ultra-low sulfur fuel
oil standard. Illinois EPA replied that it already requires consistent
NO<INF>X</INF> and SO<INF>2</INF> controls as well as an ultra-low
sulfur fuel oil standard. In response to MANE-VU's request regarding
the pursuit of energy initiatives, Illinois EPA noted Illinois'
priorities on energy efficiency and other clean energy technologies.
Arkansas requested that Illinois perform a four-factor analysis of
Prairie State Generating Station because of its anticipated impact on
visibility in the Upper Buffalo Wilderness Area. Illinois EPA replied
that it would perform a four-factor analysis on this source. Missouri
requested that Illinois consider performing four-factor analyses on
Electric Energy Inc.--Joppa, Prairie State Generating Station, Southern
Illinois Power Cooperative--Marion, and Dynegy Midwest Generation LLC--
Baldwin. Illinois EPA addressed these sources in its 2024 SIP
submission and cooperated with Missouri through LADCO and CenSARA.
Illinois EPA did not receive any replies disagreeing with its
responses. Section XIII of Illinois' SIP submission and section 5 of
the EPA's November 12, 2025, TSD provide detailed summaries of
Illinois' consultation with States, Tribes, and RPOs.
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\44\ The Mid-Atlantic/Northeast Visibility Union (MANE-VU) is
the RPO for the Northeastern and Mid-Atlantic State and Tribal
governments, which include Connecticut, Delaware, the District of
Columbia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey,
New York, Pennsylvania, Penobscot Indian Nation, Rhode Island, St.
Regis Mohawk Tribe, and Vermont. MANE-VU's request and Illinois'
response is addressed in section XIII and appendix D of Illinois'
2024 SIP submission.
\45\ Arkansas' request and Illinois' response is addressed in
section XIII and appendix C of Illinois' 2024 SIP submission.
\46\ Missouri's request and Illinois' response are described in
attachment 4 to Illinois' 2024 SIP submission.
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The EPA proposes to find that Illinois has satisfied the
consultation requirements of 40 CFR 51.308(f)(2)(ii). Illinois has met
the 40 CFR 51.308(f)(2)(ii)(A) and (B) requirements with its
participation in the LADCO consultation process plus its individual
communication with contributing States and RPOs. There were no
disagreements with any other State, therefore 40 CFR
51.308(f)(2)(ii)(C) does not apply to Illinois.
The requirements of 40 CFR 51.308(f)(2)(iii) provide that a State
must document the technical basis for its decision making to determine
the emission reduction measures that are necessary to make reasonable
progress. The documentation requirement of 40 CFR 51.308(f)(2)(iii)
provides that States may meet their obligations to document the
technical bases on which they are relying to determine the emission
reductions measures that are necessary to make reasonable progress
through an RPO, as long as the process has been ``approved by all State
participants.''
Illinois EPA adequately documented the technical basis that it
relied on in determining the emission reduction measures that are
necessary to make reasonable progress. By referencing and including
LADCO's 2021 TSD as appendix B to its 2024 SIP submission, Illinois EPA
also documented the Memorandum of Agreements between the Region 5
States and LADCO as well as the agreement from the States to use the
analysis process provided by LADCO for regional haze efforts.
In addition to including LADCO's 2021 TSD as appendix B to its 2024
SIP submission, Illinois EPA described the technical analyses performed
by LADCO and the EPA that the State relied upon for modeling visibility
impacts of Illinois sources on Class I areas and projecting 2028
visibility conditions.
The cost and engineering analyses performed by Illinois EPA to
address the four statutory factors were summarized in section V of the
State's SIP submission and described in detail in appendix A to the
submission.
Throughout its 2024 SIP submission, Illinois provided 2016
emissions data and other information used by LADCO to calculate Q/d
values and project 2028 visibility conditions. Illinois EPA explained
that because LADCO's Q/d analysis was performed in 2017, the 2016
emissions data used for the analysis was the best and most recent data
available at the time. Also, as mentioned above, Illinois EPA reasoned
that there have been no emissions increases large enough to make use of
[[Page 9789]]
the 2016 data inappropriate. Illinois EPA also provided Clean Air
Markets Program Data (CAMPD) \47\ from 2018 to 2022 that it had
considered as well as the 2014, 2017, and 2020 NEI that it had
submitted to the EPA to comply with the triennial reporting
requirements of 40 CFR 51 subpart A.
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\47\ The EPA's CAMPD information is publicly available at
<a href="https://campd.epa.gov/">https://campd.epa.gov/</a>.
---------------------------------------------------------------------------
As documented in Illinois' 2024 SIP submission, LADCO's analyses
included the collection and analysis of ambient monitoring data,
including the IMPROVE monitoring data. In section XII of its 2024 SIP
submission, Illinois EPA described its monitoring network, which it
uses to measure the ambient concentrations of pollutants including
those that contribute to visibility degradation. Illinois also included
its annual 2023 Ambient Air Monitoring Network Plan as appendix E to
its 2024 SIP submission and committed to maintaining its monitoring
network in section I of its 2024 SIP submission.
The EPA proposes to find that Illinois' documentation of the
technical basis of the long-term strategy, including the modeling,
monitoring, engineering, cost, and emissions information discussed
above, satisfies the requirements of 40 CFR 51.308(f)(2)(iii).
The provisions of 51.308(f)(2)(iii) require that the emissions
information considered to determine the measures that are necessary to
make reasonable progress include information on emissions for the most
recent year for which the State has submitted triennial emissions data
to the EPA (or a more recent year), with a 12-month exemption period
for newly submitted data. The most recent triennial NEI at the time of
Illinois' SIP submission was 2020. Illinois EPA's regional haze SIP
revision for the second implementation period included NEI data for
2014, 2017, and 2020. For its four-factor analyses and demonstrations
of existing effective controls, Illinois EPA used 2015 to 2022
emissions data where applicable, including 2018--2022 data from CAMPD
and 2028 projections from LADCO and ERTAC. Based on Illinois EPA's
consideration and analysis of the emissions information to determine
measures necessary for reasonable progress, including the most recent
NEI available at the time and emissions data from other sources and
years, the EPA proposes to find that Illinois has satisfied the
emissions information requirement in 40 CFR 51.308(f)(2)(iii).
6. Five Additional Factors
In addition to the four statutory factors, section 169A(b)(2)(B) of
the CAA requires the EPA to ensure that each SIP contains a long-term
(ten to fifteen year) strategy for making reasonable progress toward
meeting the national goal of addressing impairment of visibility in
mandatory Class I Federal areas from manmade air pollution.
Accordingly, the EPA established five additional factors listed in 40
CFR 51.308(f)(2)(iv) that States must consider in developing their
long-term strategies. In section VIII of Illinois' 2024 SIP submission,
Illinois EPA explained how it had addressed this requirement. For the
reasons discussed below, the EPA proposes to find that Illinois
adequately considered the five additional factors in developing its
2024 SIP submission.
As required by 40 CFR 51.308(f)(2)(iv)(A), Illinois considered
emission reductions due to ongoing air pollution control programs.
These include State and Federal regulations reducing emissions from
point sources, on-road and non-road mobile sources, and area sources.
Illinois EPA listed over 30 standards and programs that have been--and
are expected to continue--limiting haze-forming emissions in Illinois.
Pursuant to 40 CFR 51.308(f)(2)(iv)(B), Illinois EPA considered
measures to mitigate the impacts of construction activities on
visibility in Class I areas. Illinois EPA noted that construction
activities in Illinois are unlikely to contribute significantly to
visibility impairment at Class I areas due to their distance from the
State. Illinois EPA also explained that in addition to Federal non-road
standards for construction vehicles and equipment, construction
projects in Illinois are often subject to contract restrictions,
including idling restrictions for construction vehicles and equipment;
the EPA-approved controls for non-road diesel equipment; use of newer,
cleaner, and more fuel-efficient engines for equipment; and optimizing
earthwork and excavation to minimize haul trips. Illinois EPA noted
that the State also requires the use of ultra-low sulfur diesel
fuel,\48\ which also mitigates the environmental impacts of
construction because construction equipment generally uses diesel fuel.
Finally, Illinois EPA committed to continue working with other State
and Federal agencies to ensure that environmental impacts are given due
consideration in construction project contracting.
---------------------------------------------------------------------------
\48\ 35 Illinois Administrative Code sections 214.122 and
214.305 limit the sulfur content of distillate fuel oil and residual
fuel oil used by stationary sources. 35 Illinois Administrative Code
214 is available at <a href="https://pcb.illinois.gov/documents/dsweb/Get/Document-11922/">https://pcb.illinois.gov/documents/dsweb/Get/Document-11922/</a>.
---------------------------------------------------------------------------
As required by 40 CFR 51.308(f)(2)(iv)(C), Illinois EPA considered
source retirement and replacement schedules in developing its long-term
strategy.
In accordance with 40 CFR 51.308(f)(2)(iv)(D), Illinois EPA
considered basic smoke management practices for prescribed fire used
for agricultural and wildland vegetation management purposes and chose
to prepare a statewide voluntary smoke management plan in cooperation
with State land managers. The Illinois Smoke Management Plan is
included as appendix F to Illinois' 2024 SIP submission and provides
strategies for minimizing smoke during prescribed burns, best
management practices for burns, and guidance on when to burn based on
the Air Quality Index.
As required by 40 CFR 51.308(f)(2)(iv)(E), Illinois EPA considered
the anticipated net effect on visibility due to projected changes in
point, area, and mobile source emissions over the period addressed by
its long-term strategy. This consideration led Illinois to choose to
focus on point sources for the second implementation period but to also
include measures controlling mobile and area source emissions in its
long-term strategy. Illinois included tables in its submission showing
2016 emissions of NO<INF>X</INF>, PM<INF>2.5</INF>, SO<INF>2</INF>, and
VOC from point, area, and mobile sources compared to projected 2028
emissions of the same pollutants by the same source categories.
After considering information regarding existing effective
controls, the four statutory factors in 40 CFR 51.308(f)(2)(i), the
five additional factors in 40 CFR 51.308(f)(2)(iv), and other
requirements described above, the EPA proposes to find that Illinois
has submitted a regional haze plan that meets the requirements of 40
CFR 51.308(f)(2) related to development of a long-term strategy. Thus,
the EPA proposes to find that Illinois has satisfied the applicable
requirements for making progress towards natural visibility conditions
in Class I areas that may be affected by emissions from the State.
F. Reasonable Progress Goals
Section 51.308(f)(3) contains the requirements pertaining to RPGs
for each Class I area. Section 51.308(f)(3)(i) requires a State in
which a Class I area is located to establish RPGs--one each for the
most impaired and clearest days--reflecting the visibility conditions
that will be achieved at the
[[Page 9790]]
end of the implementation period as a result of the emission
limitations, compliance schedules and other measures required under
paragraph (f)(2) to be in States' long-term strategies, as well as
implementation of other CAA requirements. The long-term strategies as
reflected by the RPGs must provide for an improvement in visibility on
the most impaired days relative to the baseline period and ensure no
degradation on the clearest days relative to the baseline period.
Section 51.308(f)(3)(ii) applies in circumstances in which a Class I
area's RPG for the most impaired days represents a slower rate of
visibility improvement than the uniform rate of progress calculated
under 40 CFR 51.308(f)(1)(vi). Under 40 CFR 51.308(f)(3)(ii)(A), if the
State in which a mandatory Class I area is located establishes an RPG
for the most impaired days that provides for a slower rate of
visibility improvement than the URP, the State must demonstrate that
there are no additional emission reduction measures for anthropogenic
sources or groups of sources in the State that would be reasonable to
include in its long-term strategy. Section 51.308(f)(3)(ii)(B) requires
that if a State contains sources that are reasonably anticipated to
contribute to visibility impairment in a Class I area in another State,
and the RPG for the most impaired days in that Class I area is above
the URP, the upwind State must provide the same demonstration.
Because Illinois has no Class I areas within its borders to which
the requirements of the visibility protection program apply in 40 CFR
part 81, subpart D, Illinois is subject to 40 CFR 51.308(f)(3)(ii)(B),
but not 40 CFR 51.308(f)(3)(i) or (f)(3)(ii)(A).
Under 40 CFR 51.308(f)(3)(ii)(B), a State that contains sources
that are reasonably anticipated to contribute to visibility impairment
in a Class I area in another State for which a demonstration by the
other State is required under 40 CFR 51.308(f)(3)(ii)(B) must
demonstrate that there are no additional emission reduction measures
that would be reasonable to include in its long-term strategy. Table
3.1 of Illinois' 2024 SIP submission shows that at each of the Class I
areas impacted by emissions from Illinois, the 2028 projected
visibility impairment is not above the adjusted URP glidepaths for the
20 percent most impaired days. Because no Class I areas impacted by
emissions from Illinois have RPGs above the 2028 URP, Illinois is not
required to demonstrate that there are no additional emission reduction
measures for anthropogenic sources or groups of sources that would be
reasonable to include in their long-term strategies. Therefore, the EPA
proposes that the demonstration requirement under 40 CFR
51.308(f)(3)(ii)(B) does not apply to Illinois.
The EPA proposes to determine that Illinois has satisfied the
applicable requirements of 40 CFR 51.308(f)(3) relating to RPGs.
G. Monitoring Strategy and Other Implementation Plan Requirements
Section 51.308(f)(6) specifies that each comprehensive revision of
a State's regional haze SIP must contain or provide for certain
elements, including monitoring strategies, emissions inventories, and
any reporting, recordkeeping and other measures needed to assess and
report on visibility. A main requirement of this section is for States
with Class I areas to submit monitoring strategies for measuring,
characterizing, and reporting on visibility impairment. Compliance with
this requirement may be met through participation in the IMPROVE
network.
Section 51.308(f)(6)(i) requires SIPs to provide for the
establishment of any additional monitoring sites or equipment needed to
assess whether reasonable progress goals to address regional haze for
all mandatory Class I Federal areas within the State are being
achieved. Section 51.308(f)(6)(ii) requires SIPs to provide for
procedures by which monitoring data and other information are used in
determining the contribution of emissions from within the State to
regional haze visibility impairment at mandatory Class I Federal areas
both within and outside the State. All provisions under 40 CFR
51.308(f)(6) apply only to States containing mandatory Class I Federal
areas listed in 40 CFR part 81, subpart D. As noted above, Illinois
does not have any mandatory Class I Federal areas located within its
borders to which the requirements of the visibility protection program
apply in 40 CFR part 81, subpart D. Therefore, 40 CFR 51.308(f)(6)(i)
and (ii) do not apply.
The provisions of 40 CFR 51.308(f)(6)(iii) require States with no
Class I areas to include procedures by which monitoring data and other
information are used in determining the contribution of emissions from
within the State to regional haze visibility impairment at Class I
areas in other States. States with Class I areas must establish a
monitoring program and report data to the EPA that is representative of
visibility at the Class I Federal areas. The IMPROVE network meets this
requirement. Illinois EPA does not have any Class I areas or operate
any monitoring sites under the Federal IMPROVE program. Therefore, the
RHR does not require the approval of Illinois' monitoring network.
However, Illinois EPA did include a description and a map of its
monitoring network in its 2024 SIP revision and attached the Illinois
Ambient Air Monitoring 2023 Network Plan as appendix E to the
submission. Illinois EPA explained that the procedures by which
monitoring data and other information are used to determine the
contribution of Illinois emissions to visibility impairment at all
affected Class I areas were established in conjunction with LADCO.
Sections 7.0 and 8.0 of LADCO's TSD--included as appendix B to
Illinois' 2024 SIP revision--describe the procedures.
Section 51.308(f)(6)(iv) requires the SIP to provide for the
reporting of all visibility monitoring data to the Administrator at
least annually for each Class I area in the State. As noted above,
Illinois does not have any mandatory Class I Federal areas located
within its borders to which the requirements of the visibility
protection program apply in 40 CFR part 81, subpart D. Therefore, 40
CFR 51.308(f)(6)(iv) does not apply.
Section 51.308(f)(6)(v) requires SIPs to provide for a statewide
inventory of emissions of pollutants that are reasonably anticipated to
cause or contribute to visibility impairment, including emissions for
the most recent year for which data are available and estimates of
future projected emissions. It also requires a commitment to update the
inventory periodically. Illinois' 2024 SIP submission provided
statewide inventories of such emissions and future 2028 projected
emissions in Tables 3.2, 3.3, 11.5, 11.6, and 11.7, including emissions
information from the 2014, 2017, and 2020 NEI. Additionally, Illinois
EPA provided CAMPD information for 2018 to 2022 and historical EGU
emissions information from 1999 to 2020 in Figures 3.5 and 3.6. For
future projected emissions, Illinois EPA relied on LADCO's analysis,
which estimated 2028 projected emissions of SO<INF>2</INF> and
NO<INF>X</INF> for specific facilities in the LADCO States based on
2016 emissions as well as ERTAC and State forecasts. These projected
emissions were included in Illinois' 2024 SIP submission as well as in
LADCO's TSD, which Illinois EPA included as appendix B to its 2024 SIP
submission. In its 2024 SIP submission, Illinois EPA committed to
continue updating its emissions inventory \49\ and
[[Page 9791]]
to continue working with LADCO to project future emissions of relevant
pollutants. The EPA proposes to find that Illinois has met the
requirements of 40 CFR 51.308(f)(6).
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\49\ The Air Emissions Reporting Requirements for State
emissions inventories are codified in 40 CFR part 51, subpart A.
---------------------------------------------------------------------------
H. Requirements for Periodic Reports Describing Progress Towards the
Reasonable Progress Goals
Section 51.308(f)(5) requires that periodic comprehensive revisions
of States' regional haze plans also address the progress report
requirements of 40 CFR 51.308(g)(1) through (5). The purpose of these
requirements is to evaluate progress towards the applicable RPGs for
each Class I area within the State and each Class I area outside the
State that may be affected by emissions from within that State.
Sections 51.308(g)(1) and (2) apply to all States and require a
description of the status of implementation of all measures included in
a State's first implementation period regional haze plan and a summary
of the emission reductions achieved through implementation of those
measures. Section 51.308(g)(3) applies only to States with Class I
areas within their borders and requires such States to assess current
visibility conditions, changes in visibility relative to baseline
(2000-2004) visibility conditions, and changes in visibility conditions
relative to the period addressed in the first implementation period
progress report. Section 51.308(g)(4) applies to all States and
requires an analysis tracking changes in emissions of pollutants
contributing to visibility impairment from all sources and sectors
since the period addressed by the first implementation period progress
report. This provision further specifies the year or years through
which the analysis must extend depending on the type of source and the
platform through which its emission information is reported. Finally,
40 CFR 51.308(g)(5), which also applies to all States, requires an
assessment of any significant changes in anthropogenic emissions within
or outside the State have occurred since the period addressed by the
first implementation period progress report, including whether such
changes were anticipated and whether they have limited or impeded
expected progress towards reducing emissions and improving visibility.
Prior to its 2024 SIP submission, Illinois submitted its first 5-
year progress report to the EPA on February 2, 2017, and the EPA
approved it on April 3, 2018. 83 FR 15744, April 12, 2018. Thus, the
progress report elements included in section XI of Illinois' SIP
revision for the second implementation period addressed 2017 through
2021. This is consistent with 40 CFR 51.308(f)(5), which requires
States to address the elements in 40 CFR 51.308(g)(1) through (5) for
the period since the most recent progress report.
As required by 40 CFR 51.308(g)(1), Illinois EPA described the
implementation status of the measures relied on for reasonable progress
in the first implementation period in section XI of its submission.
These included NO<INF>X</INF> and SO<INF>2</INF> emission limits in
source-specific permits for two EGUs--the City of Springfield's City
Water, Light & Power facility in Dallman and Kincaid Generation, LLC;
consent decrees mandating BART for two petroleum refineries--CITGO
Petroleum Corporation and ExxonMobil Oil Corporation; and emission
reductions at all EGUs subject to the MPS and CPS.
Pursuant to 40 CFR 51.308(g)(2), Illinois EPA summarized the
emission reductions achieved through the implementation of these
measures in Tables 4.4 through 4.7 and 11.1 through 11.4 of its
submission. Illinois EPA also reproduced the list of on-the-books
control strategies that had been included in its 2017 progress report
and provided the status of these measures.
The provisions of 40 CFR 51.308(g)(3) require States to assess
Reasonable Progress Goals, including current visibility conditions and
changes, for any Class I areas within the State. Because Illinois has
no Class I areas, the requirements of 40 CFR 51.308(g)(3) do not apply
to Illinois.
Pursuant to 40 CFR 51.308(g)(4), Tables 11.5 to 11.7 of Illinois
EPA's 2024 SIP submission tracked changes in emissions of CO,
NH<INF>3</INF>, NO<INF>X</INF>, PM<INF>10</INF>, PM<INF>2.5</INF>,
SO<INF>2</INF>, and VOCs from 2014 through 2020. Changes in
NO<INF>X</INF> and SO<INF>2</INF> emissions from all Illinois EGUs from
1999 through 2020 were also provided in Figures 3.5 and 3.6 of the 2024
SIP submission and changes in NO<INF>X</INF> and SO<INF>2</INF>
emissions from specific sources from 2018 through 2022 were provided in
section VI of the 2024 SIP submission.
Addressing 40 CFR 51.308(g)(5), Illinois EPA did not identify any
significant changes in anthropogenic emissions within the State that
have occurred since its 2011 regional haze SIP submission that could
limit or impede visibility progress. Illinois EPA reported that all
projected emission reductions anticipated in the 2011 regional haze SIP
submission and in the 2017 progress report have been realized.
The EPA proposes to find that Illinois EPA has met the requirements
of 40 CFR 51.308(g)(1) through (5).
I. Requirements for State and Federal Land Manager Coordination
CAA section 169A(d) requires States to consult with FLMs before
holding the public hearing on a proposed regional haze SIP, and to
include a summary of the FLMs' conclusions and recommendations in the
notice to the public. In addition, 40 CFR 51.308(i)(2)'s FLM
consultation provision requires a State to provide FLMs with an
opportunity for consultation that is early enough in the State's policy
analyses of its emission reduction obligation so that information and
recommendations provided by the FLMs' can meaningfully inform the
State's decisions on its long-term strategy. If the consultation has
taken place at least 120 days before a public hearing or public comment
period, the opportunity for consultation will be deemed early enough.
Regardless, the opportunity for consultation must be provided at least
sixty days before a public hearing or public comment period at the
State level. Section 51.308(i)(2) also provides two substantive topics
on which FLMs must be provided an opportunity to discuss with States:
assessment of visibility impairment in any Class I area and
recommendations on the development and implementation of strategies to
address visibility impairment. Section 51.308(i)(3) requires States, in
developing their implementation plans, to include a description of how
they addressed FLMs' comments.
Illinois engaged with FLMs at multiple points in the development
process of its SIP revision, including NPS, USFS, FWS, and the U.S.
Department of Interior--Bureau of Land Management. On March 9, 2020,
NPS emailed Illinois a list of sources recommended for four-factor
analysis. Illinois EPA shared a draft SIP revision with NPS and USFS on
August 14, 2023, thus beginning the formal FLM consultation process
over 120 days before posting the proposed SIP submission for public
comment. On October 4, 2023, Illinois EPA attended a consultation call
with NPS and USFS during which the FLMs summarized their conclusions
and recommendations for the draft SIP revision. On October 13, 2023,
Illinois received letters from NPS and USFS describing their
recommendations in technical detail. As required by 40 CFR 51.308(i)(3)
and noted in the EPA's November 12, 2025, TSD, Illinois summarized the
FLMs' initial recommendations in section XIII of its SIP submission and
included summaries of the FLMs' comments with a response to each, as
well as the full
[[Page 9792]]
letters received from the FLMs, in appendix H of its submission.
Illinois published a public notice of its proposed SIP revision on
Illinois EPA's website \50\ on January 19, 2024, beginning a 30-day
public comment period and stating that a public hearing would be held
if requested. In accordance with 40 CFR 51.308(i)(2), Illinois began
the public comment period at least 60 days after initiating the FLM
consultation process and, as required by CAA section 169A(d), included
summaries of the FLMs' recommendations in the public notice. On January
23, 2024, Illinois received requests for a hearing and an extension of
the public comment period. On January 26, 2024, Illinois published a
public notice of a virtual hearing to be held on February 27, 2024, and
of a 30-day extension of the comment period. The hearing was held as
planned on February 27, 2024. In total, Illinois received four written
comments and one oral comment during the 60-day public comment period
and concurrent hearing. Illinois included the public comments and
Illinois' responses in attachments 3 and 4 to its submission, including
a letter from NPS addressing Illinois' responses to NPS' initial
recommendations for the SIP revision.
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\50\ Illinois' proposed regional haze SIP revision submittal and
all documents related to the public comment period and hearing were
made publicly available at <a href="https://epa.illinois.gov/public-notices/general-notices.html">https://epa.illinois.gov/public-notices/general-notices.html</a>.
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The provisions of 40 CFR 51.308(i)(4) require States to provide
procedures for continuing consultation with FLMs on the implementation
of visibility protection program requirements. As an active member of
LADCO, Illinois continues to coordinate regularly with FLMs on the
implementation of visibility protection plans and the planning of
future work. In its 2024 SIP submission, Illinois committed to continue
its fulfillment of all requirements of 40 CFR 51.308, including
maintenance of adequate monitoring networks and production of emissions
inventories, progress reports, and future SIP revisions. Given
Illinois' actions recounted above, the EPA proposes to find that
Illinois has satisfied the requirements of both 40 CFR 51.308(i) and
169A(d) to consult with the FLMs on its regional haze SIP for the
second implementation period.
V. Interstate Transport for the 2012 PM2.5 and 2015 Ozone NAAQS
Infrastructure SIPs--Visibility Component
A. Background on Infrastructure SIPs
Whenever the EPA promulgates a new or revised NAAQS, CAA section
110(a)(1) requires States to make SIP submissions to provide for the
implementation, maintenance, and enforcement of the NAAQS. This
particular type of SIP submission is commonly referred to as an
``infrastructure SIP.'' These submissions must meet the various
requirements of CAA section 110(a)(2), as applicable. Due to ambiguity
in some of the language of CAA section 110(a)(2), the EPA believes that
it is appropriate to interpret these provisions in the specific context
of acting on infrastructure SIP submissions. The EPA has previously
provided comprehensive guidance on the application of these provisions
through a guidance document for infrastructure SIP submissions (EPA's
2013 Guidance) and through regional actions on infrastructure
submissions.\51\ Unless otherwise noted below, we are following that
existing approach in acting on this submission. In addition, in the
context of acting on such infrastructure submissions, the EPA evaluates
the submitting State's SIP for facial compliance with statutory and
regulatory requirements, not for the State's implementation of its
SIP.\52\ The EPA has other authority to address any issues concerning a
State's implementation of the rules, regulations, consent orders, etc.
that comprise its SIP.
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\51\ The EPA explains and elaborates on these ambiguities and
its approach to address them in its September 13, 2013, ``Guidance
on Infrastructure State Implementation Plan (SIP) Elements under
Clean Air Act sections 110(a)(1) and 110(a)(2)'' (available at
<a href="https://www3.epa.gov/airquality/urbanair/sipstatus/docs/Guidance_on_Infrastructure_SIP_Elements_Multipollutant_FINAL_Sept_2013.pdf">https://www3.epa.gov/airquality/urbanair/sipstatus/docs/Guidance_on_Infrastructure_SIP_Elements_Multipollutant_FINAL_Sept_2013.pdf</a> and included in the docket for this proposed rulemaking), as
well as in numerous agency actions, including the EPA's prior action
on Michigan's, Illinois', Minnesota's, and Wisconsin's
infrastructure SIPs to address the 2008 lead NAAQS (79 FR 27241 (May
13, 2014)).
\52\ See U.S. Court of Appeals for the Ninth Circuit decision in
Montana Environmental Information Center v. EPA, No. 16-71933 (Aug.
30, 2018).
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CAA section 110(a)(2)(D)(i)(II) prohibits emissions in one State
from interfering with visibility protection measures in another State.
On September 29, 2017, and May 16, 2019, Illinois submitted SIP
revisions addressing infrastructure requirements for the 2012
PM<INF>2.5</INF> and 2015 ozone NAAQS, respectively.
This proposed rulemaking evaluates the element of Illinois EPA's
SIP submissions for the 2012 PM<INF>2.5</INF> and 2015 ozone NAAQS
addressing the fourth component (``Prong 4'') of CAA section
110(a)(2)(D)(i)--the requirement that a State's SIP contain adequate
provisions prohibiting any source or other type of emissions activity
within the State from emitting any air pollutant in amounts which will
interfere with measures required to be included in the applicable SIP
for any other State to protect visibility.
Under the applicable requirements for visibility protection of CAA
section 110(a)(2)(D)(i)(II), States are subject to visibility and
regional haze program requirements under part C of the CAA, which
includes sections 169A and 169B. The EPA's 2013 Guidance states that
these Prong 4 requirements can be satisfied by approved SIP provisions
that the EPA has found to adequately address any contribution of that
State's sources that impact the visibility program requirements in
other States.\53\ The EPA's 2013 Guidance lays out how a State's
infrastructure SIP may satisfy Prong 4. In the second implementation
period, confirmation that the State has a fully approved regional haze
SIP that fully meets the requirements of 40 CFR 51.308 will satisfy the
requirements of Prong 4.\54\
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\53\ The EPA's 2013 Guidance at 32-33.
\54\ In the EPA's 2013 Guidance, we indicated that it may be
appropriate to supplement the guidance regarding the relationship
between regional haze SIPs and Prong 4 after second implementation
period SIPs become due, which occurred on July 31, 2021. After a
review of the EPA's 2013 Guidance and the second implementation
period regional haze requirements, the EPA maintains the
interpretation that a fully approved regional haze SIP satisfies
Prong 4 requirements in the second implementation period.
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In the second implementation period, the EPA's Regional Haze
regulations under 40 CFR 51.308(f) require that a State consider the
emission reduction measures identified by other States as being
necessary to make reasonable progress towards meeting the national
visibility goal in Class I Federal areas. Specifically, the regulations
also require a State to include in its Regional Haze SIP all measures
agreed to during that process or measures that will provide equivalent
visibility improvement. 40 CFR 51.308(f)(2)(ii). Thus, in meeting the
requirements of 40 CFR 51.308(f), an approved regional haze SIP meeting
the statutory and regulatory requirements, including 40 CFR
51.308(f)(2)(ii), will ensure that emissions from sources under an air
agency's jurisdiction are not interfering with measures required to be
included in other air agencies' plans to protect visibility and will,
therefore, satisfy Prong 4.
[[Page 9793]]
B. The EPA's Evaluation of Illinois' Infrastructure SIP Submissions
To address the requirements of CAA section 110(a)(2)(D)(i)(II),
both Illinois EPA's September 29, 2017, infrastructure SIP submission
for the 2012 PM<INF>2.5</INF> NAAQS and Illinois EPA's May 16, 2019,
submission for the 2015 ozone NAAQS discuss the State's Prevention of
Significant Deterioration program, nonattainment New Source Review
program, and regional haze program. As discussed in the ``Background on
Illinois' First Implementation Period SIP Submission'' section of this
proposed rulemaking and noted in Illinois EPA's submissions, Illinois'
regional haze SIP for the first implementation period was approved on
July 6, 2012 (77 FR 39943), effective August 6, 2012.
In this proposed rulemaking, the EPA is proposing to approve
Illinois' regional haze plan for the second implementation period. For
the reasons stated above, by meeting the statutory and regulatory
requirements of the regional haze program, including the interstate
consultation requirements in 40 CFR 51.308(f)(2)(ii), Illinois' SIP
adequately prohibits emissions from within the State that would
interfere with visibility protection measures in any other State's SIP.
Therefore, the EPA proposes that Illinois has met the applicable
section 110(a)(2)(D)(i)(II) Prong 4 requirement relating to visibility
protection for the 2012 PM<INF>2.5</INF> and 2015 ozone NAAQS.
VI. Proposed Actions
The EPA proposes to approve Illinois' SIP submission, dated June 3,
2024, as satisfying the regional haze requirements for the second
implementation period contained in 40 CFR 51.308(f). The EPA also
proposes to approve Illinois' SIP submissions, dated September 29,
2017, and May 16, 2019, as satisfying the interstate transport
infrastructure requirements related to visibility protection contained
in CAA section 110(a)(2)(D)(i)(II) for the 2012 PM<INF>2.5</INF> and
2015 ozone NAAQS.
VII. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the CAA and applicable
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in
reviewing SIP submissions, the EPA's role is to approve State choices,
provided that they meet the criteria of the CAA. Accordingly, this
action merely approves State law as meeting Federal requirements and
does not impose additional requirements beyond those imposed by State
law. For that reason, this action:
<bullet> Is not a significant regulatory action subject to review
by the Office of Management and Budget under Executive Order 12866 (58
FR 51735, October 4, 1993);
<bullet> Is not subject to Executive Order 14192 (90 FR 9065,
February 6, 2025) because SIP actions are exempt from review under
Executive Order 12866;
<bullet> Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
<bullet> Is certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
<bullet> Does not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
<bullet> Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
<bullet> Is not subject to Executive Order 13045 (62 FR 19885,
April 23, 1997) because it approves a State program;
<bullet> Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001); and
<bullet> Is not subject to requirements of section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the CAA.
In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where the EPA or an Indian Tribe
has demonstrated that a Tribe has jurisdiction. In those areas of
Indian country, the rule does not have Tribal implications and will not
impose substantial direct costs on Tribal governments or preempt Tribal
law as specified by Executive Order 13175 (65 FR 67249, November 9,
2000).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Nitrogen oxides, Ozone, Particulate matter, Sulfur oxides.
Dated: February 19, 2026.
Anne Vogel,
Regional Administrator, Region 5.
[FR Doc. 2026-03936 Filed 2-26-26; 8:45 am]
BILLING CODE 6560-50-P
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This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.