[Federal Register Volume 90, Number 116 (Wednesday, June 18, 2025)]
[Proposed Rules]
[Pages 25929-25944]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-11261]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R09-OAR-2025-0203; FRL-12755-01-R9]
Approval of Air Quality Implementation Plans; California;
Regional Haze State Implementation Plan for the Second Implementation
Period
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 California on August 9, 2022 (hereinafter the ``2022
California Regional Haze Plan'' or ``the Plan''), under the Clean Air
Act (CAA) and the EPA's Regional Haze Rule for the program's second
implementation period. California's SIP submission addresses 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, including regional haze, in mandatory Class I
Federal areas. The SIP submission also addresses other applicable
requirements for the second implementation period of the regional haze
program. The EPA is proposing this action pursuant to CAA sections 110
and 169A. The EPA is also withdrawing its previous proposed rule to
partially approve and partially disapprove California's regional haze
SIP revision as published in the Federal Register on December 19, 2024.
DATES: Written comments must be received on or before July 18, 2025. As
of June 18, 2025, the proposed rule published on December 19, 2024, at
89 FR 103737, is withdrawn.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2025-0203 at https://www.regulations.gov. For comments submitted at
Regulations.gov, follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
Regulations.gov. The EPA may publish any comment received to its public
docket. Do not submit electronically any information you consider to be
confidential business information (CBI) or other information whose
disclosure is restricted by statute. Multimedia submissions (audio,
video, etc.) must be accompanied by a written comment. The written
comment is considered the official comment and should include
discussion of all points you wish to make. The EPA will generally not
consider comments or comment contents located outside of the primary
submission (i.e., on the web, cloud, or other file sharing system). For
additional submission methods, 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 https://www.epa.gov/dockets/commenting-epa-dockets. If you need assistance in a
language other than English or if you are a person with a disability
who needs a reasonable accommodation at no cost to you, please contact
the person identified in the FOR FURTHER INFORMATION CONTACT section.
FOR FURTHER INFORMATION CONTACT: Emily Millar, Geographic Strategies
and Modeling Section (ARD-2-2), Planning & Analysis Branch, EPA Region
IX, 75 Hawthorne Street, San Francisco, CA 94105, 213-244-1882, or by
email at [email protected].
SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us,''
and ``our'' refer to the EPA.
Table of Contents
I. What action 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. Withdrawal of Prior Proposed Disapproval
V. The EPA's Rationale for Proposing Approval
VI. The EPA's Evaluation of California's Regional Haze Submission
for the Second Implementation Period
A. Identification of Class I Areas
B. Calculations of Baseline, Current, and Natural Visibility
Conditions; Progress to Date; and the Uniform Rate of Progress
C. Long-Term Strategy for Regional Haze
D. Reasonable Progress Goals
E. Monitoring Strategy and Other Implementation Plan
Requirements
F. Requirements for Periodic Reports Describing Progress Towards
the Reasonable Progress Goals
G. Requirements for State and Federal Land Manager Coordination
VII. Proposed Action
VIII. Statutory and Executive Order Reviews
I. What action is the EPA proposing?
On August 9, 2022, the California Air Resources Board (CARB)
submitted the 2022 California Regional Haze Plan to address the
requirements of the CAA's regional haze program pursuant to CAA
sections 169A and 169B and 40 CFR 51.308. On December 19, 2024, the EPA
proposed to approve the elements of the Plan related to requirements
contained in 40 CFR 51.308(f)(1), 40 CFR 51.308(f)(4)-(6), and 40 CFR
51.308 (g)(1)-(5) and to disapprove the elements of the Plan related to
requirements contained in 40 CFR 51.308(f)(2), 40 CFR 51.308(f)(3), and
40 CFR 51.308(i)(2)-(4).\1\ The EPA is now withdrawing that proposal
and is proposing to fully approve the Plan for the reasons described in
this document.
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\1\ 89 FR 103737.
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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.\2\ 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 2017 RHR.\3\ 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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\2\ See 90 FR 13516 (March 24, 2025).
\3\ See 82 FR 3078 (January 10, 2017).
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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.\4\ The CAA
establishes
[[Page 25930]]
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.'' \5\
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\4\ CAA 169A. 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.
\5\ CAA 169A(a)(1).
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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 (SO2), nitrogen oxides (NOX), and, in
some cases, volatile organic compounds (VOC) and ammonia
(NH3)). Fine particle precursors react in the atmosphere to
form fine particulate matter (PM2.5), which impairs
visibility by scattering and absorbing light. Visibility impairment
reduces the perception of clarity and color, as well as visible
distance.\6\
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\6\ 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-1).
The formula for the deciview is 10 ln (b\ext\)/10 Mm-1).
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.\7\
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\7\ CAA 169A(b)(2). The RHR expresses the statutory requirement
for states to submit plans addressing out-of-state class I areas by
providing that states must address visibility impairment ``in each
mandatory Class I Federal area located outside the State that may be
affected by emissions from within the State.'' 40 CFR 51.308(d),
(f). See also 40 CFR 51.308(b), (f) (establishing submission dates
for iterative regional haze SIP revisions).
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On January 10, 2017, the EPA promulgated revisions to the RHR, that
apply for the second and subsequent implementation periods.\8\
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\8\ 82 FR 3078 (January 10, 2017).
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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),\9\ 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. California is a member of the
Western Regional Air Partnership (WRAP) \10\ RPO, which 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 western corridor of the United
States.
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\9\ RPOs are sometimes also referred to as ``multi-
jurisdictional organizations,'' or MJOs. For the purposes of this
notice, the terms RPO and MJO are synonymous.
\10\ See https://westar.org/about-wrap/.
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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 were required to
submit regional haze SIP revisions 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.\11\ 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 \12\ 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.\13\ 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). 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. 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.\14\ 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 emissions 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'' \15\
that states must consider in developing their long-term strategies.\16\
A state evaluates potential emissions reduction measures for those
selected sources and determines which are necessary to make reasonable
progress. Those measures are then
[[Page 25931]]
incorporated into the state's long-term strategy. After a state has
developed its long-term strategy, it then establishes Reasonable
Progress Goals (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.\17\ There are additional requirements in
the rule, including FLM consultation, that apply to all visibility
protection SIPs and SIP revisions.\18\
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\11\ CAA 169A(b)(2)(B).
\12\ 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 3078, 3091 (January 10, 2017).
\13\ See 40 CFR 51.308(f), (f)(2).
\14\ See 40 CFR 51.308(f)(1).
\15\ The five ``additional factors'' for consideration in
section 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.
\16\ See 40 CFR 51.308(f)(2).
\17\ 40 CFR 51.308(f)(2)-(3).
\18\ See e.g., 40 CFR 51.308(i).
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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.\19\ 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.'' \20\ The EPA has explained that the four-factor
analysis is an assessment of potential emissions reduction measures
(i.e., control options) for sources; ``use of the terms `compliance'
and `subject to such requirements' in section 169A(g)(1) can be read
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.'' \21\ Thus, for each source it has
selected for four-factor analysis,\22\ a state must consider a
``meaningful set'' of technically feasible control options for reducing
emissions of visibility impairing pollutants.\23\
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\19\ 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
planning period.
\20\ CAA 169A(g)(1).
\21\ 82 FR 3078, 3091.
\22\ ``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 Id. at
3088.
\23\ Id.
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The 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.\24\ 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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\24\ 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, p. 186.
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As explained above, 40 CFR 51.308(f)(2)(i) requires states to
determine the emissions 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. 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 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 section 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 emissions 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 51.3108(f)(2)(iv) separately
provides five ``additional factors'' \25\ that states must consider in
developing their long-term strategies: (1) Emissions 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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\25\ The five ``additional factors'' for consideration in
section 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 emissions limitations) are necessary to make reasonable
progress at a Class I area, it must include those measures in its
SIP.\26\ Additionally, the RHR requires that states that contribute to
visibility impairment at the same Class I area
[[Page 25932]]
consider the emissions reduction measures the other contributing states
have identified as being necessary to make reasonable progress for
their own sources.\27\ If a state has been asked to consider or adopt
certain emissions 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.\28\
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\26\ 40 CFR 51.308(f)(2)(ii)(A).
\27\ 40 CFR 51.308(f)(2)(ii)(B).
\28\ 40 CFR 51.308(f)(2)(ii)(C).
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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.'' \29\
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\29\ 82 FR 3078, 3091.
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For the second implementation period, the RPGs are set for 2028.
Reasonable progress goals are not enforceable targets.\30\ 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.''
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\30\ 40 CFR 51.308(f)(3)(iii).
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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 emissions
reduction measures would be reasonable to include in its long-term
strategy.\31\ 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.''
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\31\ 40 CFR 51.308(f)(3)(ii).
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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 subsection 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.\32\
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\32\ 40 CFR 51.308(f)(6), (f)(6)(i), (f)(6)(iv).
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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.\33\ 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.\34\
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\33\ 40 CFR 51.308(f)(6)(ii), (iii), (v).
\34\ 40 CFR 51.308(f)(6)(vi).
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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.\35\ To this end, every state's SIP revision for the second
implementation period is required to assess changes in visibility
conditions and describe the status of implementation of all measures
included in the state's long-term strategy, including BART and
reasonable progress emissions reduction measures from the first
implementation period, and the resulting emissions reductions.\36\
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\35\ See 81 FR 26942, 26950 (May 4, 2016); 82 FR 3078, 3119.
\36\ 40 CFR 51.308(g)(1) and (2).
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E. Requirements for State and Federal Land Manager Coordination
Clean Air Act 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
emissions reduction obligation so that information and recommendations
provided by the [FLM] can meaningfully inform the State's decisions on
the long-term strategy.'' \37\ 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.\38\
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.\39\
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\37\ 40 CFR 51.308(i)(2).
\38\ 40 CFR 51.308(i)(3).
\39\ 40 CFR 51.308(i)(4).
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IV. Withdrawal of Prior Proposed Disapproval
On December 19, 2024, the EPA published a notice of proposed
rulemaking proposing partial approval and partial disapproval of the
2022 California Regional Haze Plan.\40\ During the 45-day comment
period, we received one comment letter opposing disapproval and five
comment letters in support of disapproval. In this
[[Page 25933]]
document, we are withdrawing our December 19, 2024 proposed
disapproval. We are now reproposing the action as an approval based on
a change in policy, as discussed in Section V of this document.
Commenters who would like the EPA to consider any comments submitted on
the December 19, 2024 proposal that are relevant to this proposed
action must resubmit those comments during the comment period for this
proposed action.
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\40\ 89 FR 47398.
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V. The EPA's Rationale for Proposing Approval
The EPA is now proposing to approve the 2022 California Regional
Haze Plan because we have determined that it meets the applicable
statutory and regulatory requirements. The Plan included evaluations,
including information on the four CAA section 169(g)(1) factors as
applied to mobile sources, and a four-factor analysis for a stationary
source. California also considered historical emissions data, existing
control technologies on major sources, and the large NOX
reductions and visibility improvements that have already occurred in
California and nearby Class I areas during the first and second
planning periods. Because the State assessed the potential for
additional measures, considered the four statutory factors, and the
projected that 2028 visibility conditions for the most impaired days at
all Class I areas influenced by emissions from California sources are
below the URP, with one exception as discussed in section VI.C.4 below,
the EPA proposes to find that the Plan meets the statutory and
regulatory requirement to make reasonable progress towards the national
visibility goal.
In this proposed action, the EPA notes that it is the Agency's
policy, as announced in the EPA's recent proposed approval of the West
Virginia Regional Haze SIP, that where visibility conditions for a
Class I area impacted by a State for the most impaired days, are
projected to be below the URP in 2028, and the State has considered the
four statutory factors, the State has presumptively demonstrated
reasonable progress for the second implementation period for that
area.\41\ The EPA acknowledges that this proposed action reflects a
change in policy as to how the URP should be used in the evaluation of
regional haze second planning period SIP revisions. However, the EPA
finds that this policy aligns with the purpose of the statute and RHR,
which is achieving ``reasonable'' progress, not maximal progress,
toward Congress' natural visibility goal. In addition, this policy
aligns with comments submitted by CARB during the public comment period
on our initial proposal.\42\
---------------------------------------------------------------------------
\41\ 90 FR 16478, 16483 (April 18, 2025).
\42\ Letter dated February 23, 2025, from Edie Chang, Deputy
Executive Officer, CARB, to Cheree Peterson, Acting Regional
Administrator, EPA Region 9, p. 7.
---------------------------------------------------------------------------
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 determined by drawing a straight line from the measured 2000-2004
baseline conditions (in deciviews) for the 20 percent most impaired
days at each Class I area to the estimated 20 percent most impaired
days natural conditions (in deciviews) in 2064. From this linear
regression, a URP value can be calculated for each year between 2004
and 2064. For each Class I area, there is a regulatory requirement to
compare the projected visibility impairment represented by the RPG for
the most impaired days at the end of each planning period to the URP
(e.g., in 2028 for the second planning period).\43\ If the projected
RPG is above the URP--that is, if visibility improvements are not
tracking toward natural visibility conditions by 2064--then an
additional ``robust demonstration'' requirement is triggered for each
state that contributes to that Class I area.\44\
---------------------------------------------------------------------------
\43\ 40 CFR 51.308(f)(1)(vi). We note that RPGs are a regulatory
construct that we developed to address 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 3078,
3091-3092 (January 10, 2017).
\44\ 40 CFR 51.308(f)(3)(ii).
---------------------------------------------------------------------------
In comments on the EPA's initial proposal, California stated that:
. . . the 2022 California Regional Haze Plan includes an effective
long-term strategy that is approvable and provides for reasonable
further progress goals for the most impaired days to be at or below
the uniform rate of progress . . . California is meeting or
exceeding the uniform rate of progress. California believes that the
2028 RPGs for the most impaired days are reasonable and should be
approved.\45\
---------------------------------------------------------------------------
\45\ Letter dated February 23, 2025, from Edie Chang, Deputy
Executive Officer, CARB, to Cheree Peterson, Acting Regional
Administrator, EPA Region 9, p. 7.
In this proposed action, the EPA is proposing to approve the 2022
California Regional Haze Plan because the State evaluated potential
additional measures, considered the four statutory factors, and the
projected 2028 visibility conditions on the most impaired days at the
affected Class I areas are below the URP, with one exception as
discussed in section VI.C.4 below, thus supporting the State's decision
regarding reasonable progress for the second planning period.
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.'' \46\ The EPA's new policy
is that so long as projected 2028 visibility conditions for most
impaired days at a Class I area impacted by a state are below the URP
and the State considers the four factors, the State will have
presumptively demonstrated reasonable progress for the second planning
period for that area. As stated above, the EPA believes that this new
policy aligns with the purpose of the statute and RHR, which is
achieving ``reasonable'' progress, not maximal progress, toward
Congress' natural visibility goal.
---------------------------------------------------------------------------
\46\ 566 U.S. 502, 515 (2009) (citing 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).
---------------------------------------------------------------------------
In the 2017 RHR Revisions, the EPA addressed the role of the URP as
it relates to a State's development of its second planning period SIP
revision.\47\ Specifically, in response to comments suggesting that the
URP should be considered a ``safe harbor'' and 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.\48\ 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.\49\ Other 2017 RHR
comments indicated a similar approach, such as ``a somewhat narrower
entrance to a `safe harbor,' '' by
[[Page 25934]]
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.\50\ In response, the EPA stated that we did not
agree with either of these recommendations because ``[t]he 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.'' \51\ We concluded that,
``[t]reating 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.'' \52\ However, so long as a State considers the
four factors, the presumption that a Class I area for which projected
2028 visibility conditions on the most impaired days are 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. The EPA
invites comments on this proposed policy.
---------------------------------------------------------------------------
\47\ 82 FR 3078 (January 10, 2017).
\48\ Id. at 3099.
\49\ Id.
\50\ Id.
\51\ Id.
\52\ Id.
---------------------------------------------------------------------------
In sum, California selected a number of sources, evaluated
emissions control measures, and considered the four statutory factors.
In addition, with one exception, as discussed in section VI.C.4 of this
document, visibility conditions on the most impaired days at all Class
I areas to which California contributes are projected to be below the
URP in 2028. In light of these facts, the EPA is proposing to approve
the 2022 California Regional Haze Plan. The EPA's determinations are
described in more detail in section VI of this document.
VI. The EPA's Evaluation of California's Regional Haze Submission for
the Second Implementation Period
The EPA invites comments on the following subsections that contain
our evaluation of the Plan with respect to the requirements of the CAA
and RHR for the second planning period of the regional haze program.
A. 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,'' \53\ 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.
---------------------------------------------------------------------------
\53\ 64 FR 35714, 35721 (July 1, 1999).
---------------------------------------------------------------------------
California has 29 Class I areas within its borders: Redwood
National Park; Marble Mountain Wilderness; Lava Beds National Monument;
South Warner Wilderness; Thousand Lakes Wilderness; Lassen Volcanic
National Park; Caribou Wilderness; Yolla Bolly-Middle Eel Wilderness
(includes land managed by USBLM); Point Reyes National Seashore;
Ventana Wilderness; Pinnacles National Monument; Desolation Wilderness;
Mokelumne Wilderness; Emigrant Wilderness; Hoover Wilderness; Yosemite
National Park; Ansel Adams Wilderness; Kaiser Wilderness; John Muir
Wilderness; Kings Canyon National Park; Sequoia National Park; Dome
Lands Wilderness; San Rafael Wilderness; San Gabriel Wilderness;
Cucamonga Wilderness; San Gorgonio Wilderness; San Jacinto Wilderness;
Agua Tibia Wilderness; and Joshua Tree National Park.
In its submission, CARB also assessed the contribution of emissions
from California to visibility impairment at Class I areas in three
neighboring states: Oregon, Nevada, and Arizona.\54\ CARB noted that
the projected share of ammonium nitrate and ammonium sulfate
attributable to California sources ranges from 0.1 to 1.7 percent and
0.1 to 1.0 percent, respectively, of the total light extinction budgets
at Class I areas in neighboring states.\55\
---------------------------------------------------------------------------
\54\ 2022 California Regional Haze Plan, pp. 64-68.
\55\ Id. at 64.
---------------------------------------------------------------------------
As discussed in further detail below, the EPA is proposing to find
that the 2022 California Regional Haze Plan meets the requirements of
40 CFR 51.308(f)(2) related to the development of a long-term strategy
and the requirements of 40 CFR 51.308(f)(3) related to reasonable
progress goals. Thus, we propose to find that California has satisfied
the applicable requirements for making reasonable progress towards
natural visibility conditions in Class I areas that may be affected be
emissions from the state.
B. 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.\56\
---------------------------------------------------------------------------
\56\ 40 CFR 51.308(f)(1)(vi)(B).
---------------------------------------------------------------------------
In the 2022 California Regional Haze Plan, CARB used visibility
data from IMPROVE monitoring sites for 2000-2004 for baseline
visibility.\57\ CARB also obtained visibility data from IMPROVE
monitoring data for 2014-2018, which it used to represent current
visibility conditions. CARB determined natural visibility by estimating
the natural concentrations of visibility-impairing pollutants and then
calculating the resultant total light extinction with the IMPROVE
algorithm. Comparison of baseline conditions to natural visibility
conditions shows the improvement necessary to attain natural visibility
by 2064, measured in deciviews of improvement per year, that represents
the URP. The calculations of baseline, current, and natural visibility
conditions, as well as progress to date and progress remaining to
achieve natural visibility conditions (``Difference'') can be found in
Chapter 2 of the 2022 California Regional Haze Plan and are summarized
in Tables 1 and 2 of this document.
---------------------------------------------------------------------------
\57\ Plan, p. 22.
[[Page 25935]]
Table 1--Visibility Conditions for Clearest Days
[dv]
----------------------------------------------------------------------------------------------------------------
Progress
IMPROVE site Class I areas Baseline Current to date Natural Difference
----------------------------------------------------------------------------------------------------------------
LABE1.................... Lava Beds National 3.2 2.5 0.7 1.3 1.2
Monument; South Warner
Wilderness Area.
REDW1.................... Redwood National Park.... 6.1 5.3 0.8 3.5 1.8
TRIN1.................... Marble Mountain 3.4 3.1 0.3 1.2 1.9
Wilderness; Yolla Bolly-
Middle Eel Wilderness
Area.
LAVO1.................... Caribou Wilderness Area; 2.7 2.2 0.5 1.0 1.2
Lassen Volcanic National
Park; Thousand Lakes
Wilderness.
BLIS1.................... Desolation Wilderness 2.5 1.8 0.7 0.4 1.4
Area; Mokelumne
Wilderness Area.
PORE1.................... Point Reyes National 10.5 8.2 2.3 4.8 3.4
Seashore.
YOSE1.................... Emigrant Wilderness Area; 3.4 2.9 0.5 1.0 1.9
Yosemite National Park.
HOOV1.................... Hoover Wilderness Area... 1.4 1.0 0.4 0.1 0.9
KAIS1.................... Ansel Adams Wilderness 2.3 1.5 0.8 0.0 1.5
Area; John Muir
Wilderness Area; Kaiser
Wilderness Area.
PINN1.................... Pinnacles National Park; 8.9 7.7 1.2 3.5 4.2
Ventana Wilderness Area.
SEQU1.................... Kings Canyon National 8.8 7.0 1.8 2.3 4.7
Park; Sequoia National
Park.
RAFA1.................... San Rafael Wilderness 6.5 4.9 1.6 1.8 3.1
Area.
DOME1.................... Domeland Wilderness Area. 5.1 4.4 0.7 1.2 3.2
SAGA1.................... Cucamonga Wilderness 4.8 2.8 2.0 0.4 2.4
Area; San Gabriel
Wilderness Area.
SAGO1.................... San Gorgonio Wilderness 5.4 3.3 2.1 1.2 2.1
Area; San Jacinto
Wilderness Area.
JOSH1.................... Joshua Tree National Park 6.1 4.7 1.4 1.7 3.0
AGTI1.................... Agua Tibia Wilderness 9.6 7.0 2.6 2.9 4.1
Area.
----------------------------------------------------------------------------------------------------------------
Source: 2022 California Regional Haze Plan, Tables 2-3, 2-4, 2-6, 2-7, 2-9 and 2-10. Baseline conditions are for
2000-2004. Current conditions are for 2014-2018. Progress to date is Baseline minus Current. Difference is
Current minus Natural conditions.
Table 2--Visibility Conditions for Most-Impaired Days
[dv]
----------------------------------------------------------------------------------------------------------------
Progress
IMPROVE site Class I areas Baseline Current to date Natural Difference
----------------------------------------------------------------------------------------------------------------
LABE1.................... Lava Beds National 11.3 9.7 1.6 6.2 3.5
Monument; South Warner
Wilderness Area.
REDW1.................... Redwood National Park.... 13.7 12.6 1.1 8.6 4.0
TRIN1.................... Marble Mountain 11.9 10.4 1.5 6.5 3.9
Wilderness; Yolla Bolly-
Middle Eel Wild. Area.
LAVO1.................... Caribou Wilderness Area; 11.5 10.2 1.3 6.1 4.1
Lassen Volcanic National
Park; Thousand Lakes
Wilderness.
BLIS1.................... Desolation Wilderness 10.1 9.3 0.8 4.9 4.4
Area; Mokelumne
Wilderness Area.
PORE1.................... Point Reyes National 19.4 15.3 4.1 9.7 5.6
Seashore.
YOSE1.................... Emigrant Wilderness Area; 13.5 11.6 1.9 6.3 5.3
Yosemite National Park.
HOOV1.................... Hoover Wilderness Area... 8.9 7.8 1.1 4.9 2.9
KAIS1.................... Ansel Adams Wilderness 12.9 11.0 1.9 6.1 4.9
Area; John Muir
Wilderness Area; Kaiser
Wilderness Area.
PINN1.................... Pinnacles National Park; 17.0 14.1 2.9 6.9 7.2
Ventana Wilderness Area.
SEQU1.................... Kings Canyon National 23.2 18.4 4.8 6.3 12.1
Park; Sequoia National
Park.
RAFA1.................... San Rafael Wilderness 17.3 14.1 3.2 6.8 7.3
Area.
DOME1.................... Domeland Wilderness Area. 17.2 15.1 2.1 6.2 8.9
SAGA1.................... Cucamonga Wilderness 17.9 13.2 4.7 6.1 7.1
Area; San Gabriel
Wilderness Area.
SAGO1.................... San Gorgonio Wilderness 20.4 14.4 6.0 6.2 8.2
Area; San Jacinto
Wilderness Area.
JOSH1.................... Joshua Tree National Park 17.7 12.9 4.8 6.1 6.8
AGTI1.................... Agua Tibia Wilderness 21.6 16.3 5.3 7.7 8.6
Area.
----------------------------------------------------------------------------------------------------------------
Source: 2022 California Regional Haze Plan, Tables 2-3, 2-5, 2-6, 2-8, 2-9 and 2-11. Baseline conditions are for
2000-2004. Current conditions are for 2014-2018. Progress to date is Baseline minus Current conditions.
Difference is Current minus Natural conditions.
CARB chose to adjust its URP for international anthropogenic
impacts and to account for the impacts of wildland prescribed fires
using adjustments developed by the WRAP.\58\ The WRAP/WAQS Regional
Haze modeling platform used scaled 2014 NEI wildland prescribed fire
data for purposes of calculating the URP adjustments. WRAP used the
results from the CAMx 2028OTBa2 High-Level Source Apportionment (H-L
SA) run to determine pollutant concentrations attributable to
international emissions and to prescribed fire. These concentrations
were then used in a relative sense: the modeled relative effect
(relative response factors) of removing each of these emissions
categories was applied to projections of 2028 concentrations. This gave
a reduced 2028 concentration, and the reduction was taken as the
contribution of prescribed fire and international emissions for use in
adjusting the URP. The international and prescribed fire contributions
were therefore calculated in a manner consistent with each other and
with the 2028 projections. This approach is consistent with the default
method described in the EPA's
[[Page 25936]]
September 2019 regional haze modeling Technical Support Document (``EPA
2019 Modeling TSD'') \59\ and with the source apportionment approach
described in the EPA's 2018 Visibility Tracking Guidance.\60\ Two
different adjusted glidepath options, ``International Emissions Only
(A)'' and ``International Emissions + Wildland Rx Fire (B)'', were made
available on the WRAP TSS \61\ to adjust the URP glidepath end points
projections at 2064 for Class I federal areas on the most impaired
days.
---------------------------------------------------------------------------
\58\ Plan, pp. 51, 135-136.
\59\ Memorandum from Richard A. Wayland, Director, Air Quality
Assessment Division, EPA, to Regional Air Division Directors,
Subject: ``Availability of Modeling Data and Associated Technical
Support Document for the EPA's Updated 2028 Visibility Air Quality
Modeling,'' September 19, 2019, available at https://www.epa.gov/visibility/technical-support-document-epas-updated-2028-regional-haze-modeling.
\60\ Memorandum from Richard A. Wayland, Director, Air Quality
Assessment Division, EPA, to Regional Air Division Directors,
Subject: ``Technical Guidance on Tracking Visibility Progress for
the Second Implementation Period of the Regional Haze Program,''
December 20, 2018, available at https://www.epa.gov/sites/default/files/2018-12/documents/technical_guidance_tracking_visibility_progress.pdf.
\61\ WRAP Technical Support System, http://views.cira.colostate.edu/tssv2/.
Table 3--URP for Most-Impaired Days
[dv/year]
------------------------------------------------------------------------
Unadjusted Adjusted
IMPROVE site Class I area URP URP
------------------------------------------------------------------------
LABE1................. Lava Beds National 0.09 0.07
Monument; South
Warner Wilderness
Area.
REDW1................. Redwood National Park. 0.09 0.07
TRIN1................. Marble Mountain 0.09 0.05
Wilderness Area;
Yolla Bolly-Middle
Eel Wilderness Area.
LAVO1................. Thousand Lakes 0.09 0.06
Wilderness Area;
Lassen Volcanic
National Park;
Caribou Wilderness
Area.
BLIS1................. Desolation Wilderness 0.09 0.06
Area; Mokelumne
Wilderness Area.
PORE1................. Point Reyes National 0.16 0.14
Seashore.
YOSE1................. Emigrant Wilderness 0.12 0.08
Area; Yosemite
National Park.
HOOV1................. Hoover Wilderness Area 0.07 0.03
KAIS1................. Ansel Adams Wilderness 0.11 0.06
Area; John Muir
Wilderness Area;
Kaiser Wilderness
Area.
PINN1................. Pinnacles National \a\ 0.11 0.13
Park; Ventana
Wilderness Area.
SEQU1................. Kings Canyon National 0.28 0.21
Park; Sequoia
National Park.
RAFA1................. San Rafael Wilderness 0.18 0.14
Area.
DOME1................. Domeland Wilderness 0.18 0.13
Area.
SAGA1................. San Gabriel Wilderness 0.20 0.17
Area; Cucamonga
Wilderness Area.
SAGO1................. San Gorgonio 0.24 0.20
Wilderness Area; San
Jacinto Wilderness
Area.
JOSH1................. Joshua Tree National 0.19 0.15
Park.
AGTI1................. Agua Tibia Wilderness 0.23 0.18
Area.
------------------------------------------------------------------------
Source: 2022 California Regional Haze Plan, Tables 8-3, 8-4, 8-5.
\a\ The unadjusted URP for the PINN1 IMPROVE monitor reported in the
Plan appears to have been incorrectly transcribed from its source. The
reported value of 0.11 dv/year should actually be 0.17 dv/year, based
on the 2004 and the 2024 natural conditions endpoint data reported in
the WRAP TSS. This error does not affect other calculations or
conclusions in the Plan.
We propose to find that the 2022 California Regional Haze Plan
meets the requirements of 40 CFR 51.308(f)(1) related to the
calculations of baseline, current, and natural visibility conditions;
progress to date; differences between current visibility conditions and
natural visibility conditions, and the URP for each of its Class I
areas for the second implementation period. We also propose to find
that CARB has estimated the impacts from anthropogenic sources outside
the United States and wildland prescribed fires using scientifically
valid data and methods.
C. 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 develop a long-term
strategy for making reasonable progress towards the national visibility
goal.\62\ 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 section
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 emissions reduction
measures for inclusion in the long-term strategy.\63\
---------------------------------------------------------------------------
\62\ CAA 169A(b)(2)(B).
\63\ 40 CFR 51.308(f)(2)(iii).
---------------------------------------------------------------------------
The consultation requirements of section 51.308(f)(2)(ii) provide
that states must consult with other states that are reasonably
anticipated to contribute to visibility impairment in the same Class I
area to develop coordinated emissions management strategies containing
the emissions reductions measures that are necessary to make reasonable
progress. Section 51.308(f)(2)(ii)(A) and (B) require states to
consider the emissions reduction measures identified by other states as
necessary for reasonable progress and to include any 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.
Section 51.308(f)(2)(iii) requires 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 following sections summarize how the 2022 California Regional
Haze Plan addressed the requirements of section 51.308(f)(2) and the
EPA's evaluation of the Plan with respect to those requirements.
1. Determination of Which Pollutants to Consider
To evaluate which pollutants had the largest impact at California's
Class I areas, CARB considered light extinction
[[Page 25937]]
budgets that showed the relative contribution from different pollutants
measured during 2014-2018 at IMPROVE monitors in the State. Overall
(including both U.S. and non-U.S. sources) CARB found that, on the most
impaired days, ammonium nitrate and ammonium sulfate were responsible
for the largest portion of the light extinction budgets at sites near
urban areas, while ammonium sulfate and organic mass formed the largest
portion of light extinction budgets at sites further from urban
areas.\64\ When looking only at U.S. anthropogenic sources, CARB
concluded that ammonium nitrate was generally the dominant visibility-
reducing PM species, comprising an average of 49 percent of light
extinction at Class I areas in California during 2014-2018.\65\ CARB
also noted that, in prospective light extinction budgets developed for
2028, ammonium nitrate comprises an average of 38 percent of light
extinction at Class I areas in California. Based on these
considerations, CARB chose to focus its long-term strategy solely on
NOX, which is considered the limiting precursor for ammonium
nitrate.
---------------------------------------------------------------------------
\64\ 2022 California Regional Haze Plan, pp. 69-70.
\65\ Id. at 72.
---------------------------------------------------------------------------
2. Source Selection
CARB states that its source-selection goal for this regional haze
plan was to consider sources that accounted for at least 50 percent of
the NOX emissions in both the 2014 and 2017 emissions
inventories. Noting the significant role of mobile source emissions in
California and the State's authority to establish emissions standards
for certain mobile sources, CARB chose to focus its source-selection
process on mobile sources, but also considered stationary sources.
a. Mobile Sources
CARB provided a summary of 2017 and projected 2028 NOX
emissions in tons per day (tpd) from various mobile source sectors in
Table 5-1 of the Plan, which is reproduced as Table 4 of this document.
Based on these data, CARB selected light and medium-duty vehicles,
heavy-duty trucks, off-road equipment, trains, and ocean-going vessels
for four-factor analysis, explaining that emissions from these five
source groups account for 60 percent of NOX emissions in the
2017 inventory and are projected to account for 50 percent of
NOX emissions in 2028.\66\ CARB also noted that it did not
select aircraft for analysis because federal action would be needed to
address this source category.
---------------------------------------------------------------------------
\66\ Id. at 75-76.
Table 4--CARB Mobile Source Sector Emissions
------------------------------------------------------------------------
2017 emissions Projected 2028
Sector description (tpd) emissions (tpd)
------------------------------------------------------------------------
On-Road: Heavy-Duty Trucks.......... 409 227
On-Road: Light & Medium-Duty Trucks. 111 31
On-Road: Light-Duty Passenger....... 70 26
On-Road: Other...................... 29 18
(Buses, Motorcycles, Motorhomes)....
Off-Road: Off-Road Equipment........ 222 132
Off-Road: Trains.................... 78 37
Off-Road: Aircraft.................. 46 59
Off-Road: Ocean-Going Vessels....... 28 37
Off-Road: Commercial Harbor Craft... 19 18
Off-Road: Recreational Boats........ 16 13
Off-Road: Recreational Vehicles..... 1 1
------------------------------------------------------------------------
Source: Plan Table 5-1.
b. Stationary Sources
CARB conducted a four-step process to select sources for four-
factor analysis:
Step 1: Calculate NOX emissions (Q) in tons
divided by distance (d) in km (Q/d) \67\ and screen in facilities with
a NOX Q/d greater than five for further consideration.
---------------------------------------------------------------------------
\67\ Q/d is commonly used as a surrogate metric for visibility
impacts for the purpose of selecting sources to analyze.
---------------------------------------------------------------------------
Step 2: Review device-level emission inventories and
screen out sources if actual emissions or emissions under State or
local jurisdiction resulted in a Q/d less than five.
Step 3: Review existing controls, planned controls, and
proposed operational changes. Screen out sources if this information
indicated that a full four-factor analysis would likely result in the
conclusion that reasonable controls are in place.
Step 4: Proceed with consideration and evaluation of four
statutory factors.
We discuss steps 1-3 of CARB's analysis in this section and step 4
in section IV.E.3.b of this document.
In Step 1 of its stationary source screening process, CARB
calculated NOX-only Q/d values using 2017 NEI NOX
emissions data and the distance between a stationary source and Class I
areas and selected the sources with a Q/d value greater than 5. The
results of this analysis are summarized in Table G-1 of the Plan, which
is reproduced as Table 5 of this document.
Table 5--Stationary Sources Selected at Step 1
----------------------------------------------------------------------------------------------------------------
Distance 2017 NEI
Facility name Location with maximum Q/d (km) (tpy) Q/d
----------------------------------------------------------------------------------------------------------------
Chevron Products Company.................. Point Reyes National Seashore 28 737 26.4
Lehigh Southwest Cement Company........... Point Reyes National Seashore 86 1208 14.0
Oakland Metropolitan International Airport Point Reyes National Seashore 50 1262 25.4
Phillips 66 Carbon Plant.................. Point Reyes National Seashore 43 360 8.5
[[Page 25938]]
Phillips 66 Company--San Francisco Point Reyes National Seashore 43 218 5.1
Refinery.
San Francisco International Airport....... Point Reyes National Seashore 45 5105 113.4
San Jose Airport--Norman Y Mineta......... Point Reyes National Seashore 92 884 9.6
Shell Martinez Refinery (now owned by PBF) Point Reyes National Seashore 53 916 17.2
Tesoro Refining & Marketing Company LLC... Point Reyes National Seashore 57 360 6.3
Valero Refining Company................... Point Reyes National Seashore 52 1013 19.3
CalPortland Cement--Mojave Plant.......... Domeland Wilderness Area..... 75 1531 20.5
Granite Construction--Lee Vining.......... Ansel Adams Wilderness Area.. 6 31 5.2
Kirkwood Powerhouse....................... Mokelumne Wilderness Area.... 1 10 16.6
Cal Portland Oro Grande (formerly Cucamonga Wilderness Area.... 41 1141 27.9
Riverside).
Cemex--Black Mountain Quarry.............. San Gorgonio Wilderness Area. 53 5420 101.6
Mitsubishi Cement......................... San Gorgonio Wilderness Area. 33 1944 59.7
Searles Valley Mineral.................... Domeland Wilderness Area..... 71 1517 21.3
Arcata.................................... Redwood National Park........ 17 163 9.7
Collins Pine Co........................... Caribou Wilderness Area...... 12 129 10.4
Sierra Pacific Industries--Quincy......... Caribou Wilderness Area...... 59 392 6.6
Sacramento International Airport.......... Desolation Wilderness Area... 117 737 6.3
San Diego International-Lindberg.......... Agua Tibia Wilderness Area... 74 1580 21.3
Burney Forest Products.................... Thousand Lakes Wilderness 17 190 11.2
Area.
Lehigh Southwest Cement Company........... Thousand Lakes Wilderness 56 603 10.7
Area.
Sierra Pacific Industries--Burney......... Thousand Lakes Wilderness 18 157 8.9
Area.
Wheelabrator Shasta E.C.I................. Yolla Bolly-Middle Eel 57 536 9.4
Wilderness Area.
Bob Hope Airport.......................... San Gabriel Wilderness Area.. 31 375 12.0
California Steel Industries Inc........... Cucamonga Wilderness Area.... 16 125 7.8
Chevron Products Co....................... San Gabriel Wilderness Area.. 52 729 14.0
Desert View Power......................... Joshua Tree National Park.... 24 189 7.8
John Wayne Airport........................ Cucamonga Wilderness Area.... 62 698 11.3
Long Beach Daugherty Field Airport........ San Gabriel Wilderness Area.. 49 308 6.3
Los Angeles International Airport......... San Gabriel Wilderness Area.. 49 7836 159.0
New--Indy Ontario, LLC.................... Cucamonga Wilderness Area.... 18 137 7.5
Ontario International Airport............. Cucamonga Wilderness Area.... 17 679 40.2
Palm Springs International Airport........ San Jacinto Wilderness Area.. 10 159 16.4
Phillips 66 Co/LA Refinery Wilmington Pl.. San Gabriel Wilderness Area.. 58 471 8.1
Phillips 66 Company/Los Angeles Refinery.. San Gabriel Wilderness Area.. 53 391 7.3
Tamco..................................... Cucamonga Wilderness Area.... 13 108 8.3
Tesoro Refining & Marketing (Carson)...... San Gabriel Wilderness Area.. 51 661 13.0
Tesoro Refining and Marketing (Wilmington) San Gabriel Wilderness Area.. 54 749 13.8
Torrance Refining (formerly Exxon Mobil).. San Gabriel Wilderness Area.. 52 924 17.6
----------------------------------------------------------------------------------------------------------------
Source: Plan Table G-1.
In Step 2 of its Stationary Source Screening process, CARB screened
out 17 sources based on a ``device-level inventory,'' where ``actual
emissions or emissions under State or local jurisdiction led to a Q/d
less than five.'' \68\ The sources screened out at this stage are
summarized in Table 6 of this document.
---------------------------------------------------------------------------
\68\ Id. Appendix G, p. 154.
Table 6--Stationary Sources Screened Out at Step 2
------------------------------------------------------------------------
Facility name Rationale for screening out
------------------------------------------------------------------------
Oakland Metropolitan Vast majority of emissions are from
International Airport. aircraft, for which state and local
agencies do not have authority to set
emissions limits.
San Francisco International Vast majority of emissions are from
Airport. aircraft, for which state and local
agencies do not have authority to set
emissions limits.
San Jose Airport--Norman Y Vast majority of emissions are from
Mineta. aircraft, for which state and local
agencies do not have authority to set
emissions limits.
Tesoro Refining & Marketing The refinery has been idled since 2020
Company LLC. and owner is proposing to convert the
refinery to a renewable fuels facility.
Granite Construction--Lee Per district staff, actual NOX emissions
Vining. from this source in 2017 were 0.5 tpy
and were consistent with emission from a
typical operating year.
Kirkwood Powerhouse.......... In 2014, Kirkwood Meadows Public
Utilities District transitioned to line
power and all the generators were
transitioned from prime to emergency
back-up engines. Actual NOX emissions
since 2014 have been less than 0.1 tpy.
Arcata....................... Vast majority of emissions are from
aircraft, for which state and local
agencies do not have authority to set
emissions limits.
Sacramento International Vast majority of emissions are from
Airport. aircraft, for which state and local
agencies do not have authority to set
emissions limits.
[[Page 25939]]
San Diego International- Vast majority of emissions are from
Lindberg. aircraft, for which state and local
agencies do not have authority to set
emissions limits.
Bob Hope Airport............. Vast majority of emissions are from
aircraft, for which state and local
agencies do not have authority to set
emissions limits.
Desert View Power............ Facility is located on Cabazon Indian
Reservation land.
John Wayne Airport........... Vast majority of emissions are from
aircraft, for which state and local
agencies do not have authority to set
emissions limits.
Long Beach Daugherty Field Vast majority of emissions are from
Airport. aircraft, for which state and local
agencies do not have authority to set
emissions limits.
Los Angeles International Vast majority of emissions are from
Airport. aircraft, for which state and local
agencies do not have authority to set
emissions limits.
Ontario International Airport Vast majority of emissions are from
aircraft, for which state and local
agencies do not have authority to set
emissions limits.
Palm Springs International Vast majority of emissions are from
Airport. aircraft, for which state and local
agencies do not have authority to set
emissions limits.
Tamco........................ Facility permanently was shut down in
January 2021.
------------------------------------------------------------------------
Source: Plan, Appendix G, pp. 158-165.
In Step 3 of its screening process, CARB screened out 24 stationary
sources based on its determination that ``information about existing
controls, planned controls, or planned operational changes indicated
that a full four factor analysis would likely result in the conclusion
that, for the purposes of the regional haze program, reasonable
controls are in place and no further reasonable controls are necessary
at this time.'' \69\ The controls or measures cited by CARB in making
this determination for the 24 sources include existing or anticipated
controls required by currently applicable district rules, expected
district rules, permit requirements, and/or consent decrees. The
sources screened out at this step are shown in Table 7.
---------------------------------------------------------------------------
\69\ Id. at 154.
Table 7--Stationary Sources Screened Out at Step 3
------------------------------------------------------------------------
Facility name Rationale for screening out
------------------------------------------------------------------------
Chevron Products Company..... Multiple furnaces have SCR units and
permit limits of 40 ppm NOX at 3% O2 (8-
hour average). Cogeneration turbines
have SCR units and emission limits of
<10 ppm at 15% O2 (3-hour average) and
0.20 lb/MMBtu as a 30-day rolling
average. Facility's operating permit
includes the federal interim refinery-
wide emissions limit (excluding CO
boilers) of 0.20 lb NOX/MMBtu as well as
the more stringent refinery-wide
emissions limit (excluding CO boilers)
of 0.033 lb NOX/MMBtu.
Lehigh Southwest Cement Emission limit of 2.0 lb NOX/ton of
Company. clinker under federal consent decree.
Phillips 66 Carbon Plant..... Planned decommissioning of the plant.
Phillips 66 San Francisco Planned conversion to facility that would
Refinery. process renewable feedstocks.
Shell Martinez Refinery...... Turbine boiler is equipped with an SCR
system and has NOX emission limits of
less than or equal to 5 ppmv NOX at 15%
O2. A 2001 EPA consent decree required
optimization of NOX emission controls
for other boilers. Boilers are also
subject to Bay Area Air Quality
Management District (BAAQMD) Regulation
9, Rule 10, which has been determined to
meet BARCT stringency.
Valero Refining Company...... NOX emissions are controlled through SCR
systems and low NOX burners. BAAQMD
Regulation 9, Rule 10 applies to heaters
and boilers (except for CO boilers) at
refineries and sets the refinery-wide
NOX emissions limit at 0.033 lb NOX per
MMBtu of heat input (daily average) and
facility-wide federal limit of 0.20 lb
NOX/MMBtu of heat input.
Cal Portland Mojave Plant.... EPA consent decree required installation
of selective non-catalytic reduction
(SNCR) and established an emission limit
of 2.5 lbs NOX/ton of clinker for kiln.
The kilns are also subject to Eastern
Kern District's Rule 425.3, which was
found to meet BARCT stringency.
Cemex--Black Mountain Quarry. Federal consent decree established a NOX
emission limit of 1.95 lbs/ton of
clinker. The kilns are also subject to
Mojave Desert AQMD's Rule 1161--Portland
Cement Kilns, which was revised in 2018
to meet federal RACT stringency and
California BARCT stringency.
Mitsubishi Cement The emission limit for cement kiln in the
(Cushenberry Plant). Title V permit is 2.8 lbs of NOX/ton of
clinker.
Cal Portland Oro Grande...... The emission limit for cement kiln is
2.45 lb NOX/ton of clinker.
Searles Valley Mineral....... The smallest boiler complies with a best
available control technology (BACT)
emission limit of 9 ppmv. All the
boilers are subject to Rule 1157.1,
which was adopted in 2019 to meet the AB
617 expedited BARCT requirements.
Sierra Pacific Industries-- NOX emissions are controlled by ammonia
Quincy. injection.
Burney Forest Products....... The boilers are equipped with an SNCR
unit with anhydrous ammonia injection
for NOX control. Title V permit includes
BACT emission limits for NOX.
Lehigh Southwest Cement EPA Consent Decree limits NOX emissions
Company. to 1.95 lb/ton clinker with combustion
controls or SNCR.
Sierra Pacific Industries-- NOX emissions are controlled through
Burney. ammonia injection, staged combustion
controls, flue gas recirculation, and
low NOX burners when combusting natural
gas at start-up/shutdown.
[[Page 25940]]
Wheelabrator Shasta E.C.I.... NOX emissions are controlled through
ammonia injection, staged combustion
controls, flue gas recirculation, and
low NOX burners when combusting natural
gas at start-up/shutdown.
California Steel Industries.. By January 2022, the facility is planning
to replace two existing 33 MMBtu/hr
boilers with two new 32.54 MMBtu/hr
boilers to comply with a 5 ppm NOX limit
in South Coast AQMD Rule 1146.
Chevron Products Co.......... NOX control equipment includes low NOX
burners in heaters/boilers, SCR units,
and NOX reducing catalyst in the FCCU.
Recently, the facility replaced five
heater burners with low NOX burners and
the district recently received a
proposal from the facility to install
SCR on two large heaters. South Coast
AQMD Rule 1109.1 is being developed for
all NOX emitting sources at the
refineries.
New Indy Ontario LLC......... New combined heat and power units placed
in operation in the fall of 2019 with
BACT limit of 2 ppm NOX @15% O2. Boiler
required to meet 5 ppm NOX and 5 ppm NH3
at 3 percent under South Coast AQMD's
Rule 1146.
Phillips 66 Co/Los Angeles In the last six years, equipment changes
Refinery--Carson. have included the installation of an SCR
unit on boiler 11 and the reformer
heater South Coast AQMD Rule 1109.1 is
being developed for all NOX emitting
sources at the refineries.
Phillips 66 Co/LA Refinery SCR was recently installed on the FCCU.
Wilmington. Boilers and heaters are equipped with
low NOX burners. South Coast AQMD Rule
1109.1 is being developed for all NOX
emitting sources at the refineries.
Tesoro Refining and Marketing FCCU shutdown at Wilmington completed in
Co.--Carson and Wilmington. October 2018. South Coast AQMD Rule
1109.1 is being developed for all NOX
emitting sources at the refineries.
Torrance Refining (formerly NOX control equipment at the refinery
ExxonMobil). includes low NOX burners in heaters/
boilers, SCR units, and NOX reducing
catalyst in the FCCU. South Coast AQMD
Rule 1109.1 is being developed for all
NOX emitting sources at the refineries.
------------------------------------------------------------------------
Source: Plan Appendix G, pp. 166-183.
3. Four-Factor Analyses and Control Determinations
a. Mobile Sources
For each of the selected source mobile source categories, CARB
discussed control measures that had been identified in previous state
plans and provided information related to the four reasonable progress
factors in order to ``to highlight the consideration of the four
reasonable progress factors embodied in CARB's rule making process.''
\70\ The Plan also describes a ``commitment to achieve aggregate
emissions reductions of 40 tpd of NOX emissions Statewide.''
\71\
---------------------------------------------------------------------------
\70\ Plan, Appendix H, p. 185. See also Plan pp. 83-105.
\71\ Plan p. 116.
---------------------------------------------------------------------------
b. Stationary Sources
CARB provided a four-factor analysis for a Keeler Cogeneration
Boiler at the Collins Pine Company wood products and cogeneration
facility in Chester. As part of this analysis, CARB considered several
potential control options, but concluded that the only technically
feasible options were (1) good combustion practices, which are already
in effect, and (2) SNCR. After evaluating the four factors for the SNCR
option, CARB determined that retrofit of the existing boiler system
with an SNCR system was not reasonable because ``[t]he existing boiler
configuration does not provide for adequate residence time without
injection of excess reagent, which is likely to lead to high levels of
ammonia slip.'' \72\
---------------------------------------------------------------------------
\72\ Id. at 108.
---------------------------------------------------------------------------
4. Conclusion
In sum, California selected a number of sources, evaluated
emissions control measures, and considered the four statutory factors.
In addition, projected 2028 visibility conditions at all Class I areas
in California and at most other Class I areas potentially affected by
emissions from California, are below the URP. There is one Class I area
in neighboring state, Sycamore Canyon in Arizona, where 2028 visibility
conditions for the most impaired days are projected to be above the
URP.\73\ However, as explained in the Arizona Regional Haze Plan, the
IMPROVE monitor for Sycamore Canyon (SYCA) was moved in 2015 (from
SYCA1 to SYCA2) and ``a significant increase in soil and coarse mass
extinction (two locally derived visibility impairing pollutants due to
their limited transportability) occurred following the monitor's
relocation.'' \74\ Arizona further noted that:
---------------------------------------------------------------------------
\73\ Arizona Department of Environmental Quality, ``State
Implementation Plan Revision: Regional Haze Program (2018-2028)''
(August 15, 2022) (``2022 Arizona Regional Haze Plan''), p. 102.
\74\ Id.
The impacts of monitor relocation on long-term trends of certain
visibility impairing species such as coarse mass and soil (which are
generally are more localized in impact due to their
transportability) may call into question the representativeness of a
monitor located outside of the Class I area, as is the case for
SYCA_RHTS, when assessing Class I area visibility. This is
especially true of the new SYCA2 IMPROVE monitoring site which is
closely located to a small residential community and near dirt
roads.\75\
---------------------------------------------------------------------------
\75\ Id. at 105.
Given the questions raised by ADEQ about the representativeness of
the SYCA2 monitor and particularly the role of locally emitted coarse
mass and fine soil, it reasonable to conclude that sources in
California are not the cause of 2028 projected visibility conditions at
Sycamore Canyon's being above the glidepath. Therefore, the EPA
proposes to find that the 2022 California Regional Haze Plan satisfies
the requirements of 40 CFR 51.308(f)(2).
D. Reasonable Progress Goals
Section 51.308(f)(3) contains the requirements pertaining to RPGs
for each Class I area. Because California is host to multiple Class I
areas, it is subject to both section 51.308(f)(3)(i) and, potentially,
to (ii). 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 for each Class I area--reflecting the visibility
conditions that will be achieved at the end of the implementation
period as a result of the emissions 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
[[Page 25941]]
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 section 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 emissions
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.
CARB's RPGs are set out in Table 8-1 of the Plan, which is
reproduced as Table 8 of this document. In the Plan, CARB explains that
the RPGs for the most impaired days are based on the emissions inputs
that include implementation of control programs adopted at the time of
the emissions inventory development and the additional aggregate
emission reduction commitment proposed in CARB's long-term
strategy,\76\ while the RPGs for the clearest days are equal to average
visibility conditions on the clearest days during the 2000-2004
baseline period.
---------------------------------------------------------------------------
\76\ The last column of Plan Table 7-5, p.131 is headed ``2028
Visibility Projections (dv) with Potential Additional Controls (PAC2
Emissions).'' While it is not explicitly stated in the Plan, that
was the WRAP model scenario mainly relied upon in the Plan. Unless
otherwise indicated, all of the Plan's 2028 projections and RPGs are
identical to results from WRAP modeling scenario PAC2_EPAwoF ``PAC2
EPA w/o Fire Projection,'' available in WRAP TSS modeling tools 4
and 5. The PAC2 scenario reflected ``Potential Additional
Controls,'' including California mobile source control measures; the
``woF'' means ``without fire'' in the calculation of Relative
Response Factors to apply to monitored or other modeled
concentrations.
Table 8--Baseline Conditions and RPGs for Clearest and Most Impaired Days
----------------------------------------------------------------------------------------------------------------
Most Most
Clearest Clearest impaired impaired
IMPROVE site Class I area baseline 2028 RPG baseline 2028 RPG
(dv) (dv) (dv) (dv)
----------------------------------------------------------------------------------------------------------------
LABE1.......................... Lava Beds National Monument; 3.2 3.2 11.3 8.9
South Warner Wilderness Area.
REDW1.......................... Redwood National Park.......... 6.1 6.1 13.7 11.9
TRIN1.......................... Marble Mountain Wilderness 3.4 3.4 11.9 9.5
Area; Yolla Bolly-Middle Eel
Wilderness Area.
LAVO1.......................... Thousand Lakes Wilderness Area; 2.7 2.7 11.5 9.4
Lassen Volcanic National Park;
Caribou Wilderness Area.
BLIS1.......................... Desolation Wilderness Area; 2.5 2.5 10.1 8.3
Mokelumne Wilderness Area.
PORE1.......................... Point Reyes National Seashore.. 10.5 10.5 19.4 14.4
YOSE1.......................... Emigrant Wilderness Area; 3.4 3.4 13.5 10.4
Yosemite National Park.
HOOV1.......................... Hoover Wilderness Area......... 1.4 1.4 8.9 7.1
KAIS1.......................... Ansel Adams Wilderness Area; 2.3 2.3 12.9 9.8
John Muir Wilderness Area;
Kaiser Wilderness Area.
PINN1.......................... Pinnacles National Park; 8.9 8.9 17.0 13.0
Ventana Wilderness Area.
SEQU1.......................... Kings Canyon National Park; 8.8 8.8 23.2 16.1
Sequoia National Park.
RAFA1.......................... San Rafael Wilderness Area..... 6.5 6.5 17.3 13.0
DOME1.......................... Domeland Wilderness Area....... 5.1 5.1 17.2 13.7
SAGA1.......................... San Gabriel Wilderness Area; 4.8 4.8 17.9 11.5
Cucamonga Wilderness Area.
SAGO1.......................... San Gorgonio Wilderness Area; 5.4 5.4 20.4 12.0
San Jacinto Wilderness Area.
JOSH1.......................... Joshua Tree Wilderness Area.... 6.1 6.1 17.7 11.3
AGTI........................... Agua Tibia Wilderness Area..... 9.6 9.6 21.6 14.5
----------------------------------------------------------------------------------------------------------------
Source: Plan Table 8-1: 2028 Reasonable Progress Goals for California Class I Areas.
In Plan Appendix C, CARB also provided graphs of observed
visibility, unadjusted and adjusted URP, and 2028 RPGs.\77\ From those
CARB concluded that 2028 RPGs for the most impaired days at all of
California's Class I areas are on or below the adjusted URP glidepath.
---------------------------------------------------------------------------
\77\ Those graphs have the unadjusted and adjusted URP glidepath
lines crossing each other, instead of both starting at the 2004
baseline level and having just the 2064 end point adjusted. However,
comparable graphs available from WRAP TSS modeling tool 5 show the
same placement of 2028 RPG with respected to the unadjusted and
adjusted URP glidepath line as the Plan Appendix C graphs do. All
Class I areas are below the unadjusted URP glidepath, except that
those corresponding to IMPROVE sites REDW1, LAVO1, BLIS1, DOME1 are
above the unadjusted URP glidepath but below the glidepath adjusted
for international sources and the glidepath adjusted for
internationals sources and prescribed fire.
Table 9--Current Rate of Progress and URP
----------------------------------------------------------------------------------------------------------------
Current rate Unadjusted Adjusted
IMPROVE site Class I area of progress URP (dv/ URP (dv/
(dv/year) year) year)
----------------------------------------------------------------------------------------------------------------
LABE1............................. Lava Beds National Monument; South 0.11 0.09 0.07
Warner Wilderness Area.
REDW1............................. Redwood National Park............. 0.08 0.09 0.07
TRIN1............................. Marble Mountain Wilderness Area; 0.11 0.09 0.05
Yolla Bolly-Middle Eel Wilderness
Area.
LAVO1............................. Thousand Lakes Wilderness Area; 0.09 0.09 0.06
Lassen Volcanic National Park;
Caribou Wilderness Area.
BLIS1............................. Desolation Wilderness Area; 0.06 0.09 0.06
Mokelumne Wilderness Area.
[[Page 25942]]
PORE1............................. Point Reyes National Seashore..... 0.29 0.16 0.14
YOSE1............................. Emigrant Wilderness Area; Yosemite 0.14 0.12 0.08
National Park.
HOOV1............................. Hoover Wilderness Area............ 0.08 0.07 0.03
KAIS1............................. Ansel Adams Wilderness Area; John 0.14 0.11 0.06
Muir Wilderness Area; Kaiser
Wilderness Area.
PINN1............................. Pinnacles National Park; Ventana 0.21 0.11 0.13
Wilderness Area.
SEQU1............................. Kings Canyon National Park; 0.34 0.28 0.21
Sequoia National Park.
RAFA1............................. San Rafael Wilderness Area........ 0.23 0.18 0.14
DOME1............................. Domeland Wilderness Area.......... 0.15 0.18 0.13
SAGA1............................. San Gabriel Wilderness Area; 0.34 0.20 0.17
Cucamonga Wilderness Area.
SAGO1............................. San Gorgonio Wilderness Area; San 0.43 0.24 0.20
Jacinto Wilderness Area.
JOSH1............................. Joshua Tree National Park......... 0.34 0.19 0.15
AGTI1............................. Agua Tibia Wilderness Area........ 0.38 0.23 0.18
----------------------------------------------------------------------------------------------------------------
Source: Plans Tables 8-3, 8-4, and 8-5.
With regard to the clearest days, we note that the projected
conditions for the clearest days in 2028 at all of California's Class I
areas, are significantly better than baseline conditions, according to
the WRAP modeling scenario that CARB used to set its RPGs for the most
impaired day.\78\ Therefore, CARB's RPGs for the clearest days, which
were set equal to baseline conditions, may be viewed as a conservative
projection of 2028 conditions, which provide for no degradation in
visibility for the 20 percent clearest days since the baseline period.
---------------------------------------------------------------------------
\78\ As noted previously, CARB used WRAP modeling scenario
PAC2_EPAwoF ``PAC2 EPA w/o Fire Projection.'' Results from the WRAP
TSS website, available in the docket for this action, show that for
each of California's Class I areas the 2028 projection for ``PAC2
EPA w/o Fire Projection--Clearest'' is below (i.e. less impaired
than) the ``no degradation'' line, which is set based on baseline
conditions.
---------------------------------------------------------------------------
Accordingly, we propose to determine that CARB has satisfied the
applicable requirements of 40 CFR 51.308(f)(3) relating to RPGs.
E. 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 subsection 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. In Chapter 2 of the Plan, CARB noted that it
relies on data from 17 monitoring sites operated by the IMPROVE network
to track visibility conditions in California's Class I areas.
Section 51.308(f)(6)(i) requires SIPs to provide for the
establishment of any additional monitoring sites or equipment needed to
assess whether RPGs to address regional haze for all mandatory Class I
Federal areas within the state are being achieved. CARB stated that
this requirement is ``not applicable,'' suggesting that CARB believes
the current IMPROVE network sufficient for this purpose.
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. CARB relied on source-apportionment modeling
performed by the WRAP to meet this requirement.\79\ Specifically, CARB
pointed to both high-level source apportionment modeling, which was
used to estimate how much of each haze pollutant was attributable to
several broad source categories, and low-level source apportionment
modeling, which was used to estimate how much ammonium nitrate and
ammonium sulfate is attributable to regional human-made sources.
---------------------------------------------------------------------------
\79\ Plan Chapter 4.
---------------------------------------------------------------------------
Section 51.308(f)(6)(iii) does not apply to California, as it has a
Class I area.
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, CARB
relies on data from 17 monitoring sites operated by the IMPROVE
Network.
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. California provides for emissions inventories
and estimates of future projected emissions by participating in WRAP
and by complying with the EPA's Air Emissions Reporting Rule (AERR). In
40 CFR part 51, subpart A, the AERR requires states to submit updated
emissions inventories for criteria pollutants to the EPA's Emissions
Inventory System (EIS) annually or triennially depending on the source
type. The EPA uses the inventory data from the EIS to develop the NEI,
which is a comprehensive estimate of air emissions of criteria
pollutants, criteria precursors, and hazardous air pollutants from air
emissions sources. The EPA releases an NEI every three years. In
Chapter 3 and Appendix E of the Plan, CARB provides high-level
summaries of 2014 and 2028 emissions inventories. The EPA proposes to
find that CARB meets the requirements of 40 CFR 51.308(f)(6)(v) through
its ongoing compliance with the AERR, its compilation of a statewide
emissions inventories, and its use of WRAP modeling.
Section 51.308(f)(6)(vi) requires the SIP to include other
elements, including reporting, recordkeeping, and other measures,
necessary to assess and report on visibility. The EPA proposes to find
that CARB has met the requirements of 40 CFR 51.308(f)(6) as described
above, including through its continued participation in the IMPROVE
network and the WRAP, and that no further
[[Page 25943]]
elements are necessary at this time for CARB to assess and report on
visibility pursuant to 40 CFR 51.308(f)(6)(vi).
F. 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 emissions 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 emissions information is reported. Finally,
section 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.
CARB's most recent 5-year progress report was submitted to the EPA
on June 16, 2014, and presented data analysis for the period 2007-
2011.\80\ Therefore, the current progress report is required to address
the time period beginning in 2012.
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\80\ 79 FR 58302, 58304 (September 29, 2014).
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CARB addressed the requirements of 40 CFR 51.308(g) in Chapter 10
of the Plan and provided additional supporting information in a
technical supplement submitted on August 24, 2023. Specifically, to
address 51.308(g)(1) and (2), CARB provided a summary of control
measures it adopted between 2012 and 2018, and statewide emission
trends through 2018.\81\
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\81\ Plan Table 10-1 and Figure 10-1.
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The EPA proposes to find that the Plan meets the requirements of 40
CFR 51.308(g)(1) and (2) because it describes the measures included in
the long-term strategy from the first implementation period, as well as
the status of their implementation and the emission reductions achieved
through such implementation.
The Plan also provides the 5-year baseline (2000-2004) visibility
conditions, the conditions covered in the previous progress report
(2007-2011) and current conditions (2014-2018) for the clearest and
most impaired days.\82\ The EPA therefore proposes to find that the
Plan meets the requirements of 40 CFR 51.308(g)(3).
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\82\ Id. Tables 10-4 and 10-5.
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In a technical supplement sent on August 24, 2023 (``2023
California Regional Haze Technical Supplement''),\83\ CARB provided
additional supporting information to address the requirements of 40 CFR
51.308(g)(4) and (5).\84\ Pursuant to section 51.308(g)(4), CARB
provided a summary of emissions of NOX, SO2,
PM10, PM2.5, VOCs, and NH3 from all
sources and activities, including from point, nonpoint, non-road
mobile, and on-road mobile sources for the progress report period. CARB
also provided 2012-2019 clean air markets program data for all sources
with emissions of visibility impairing pollutants. The EPA is therefore
proposing to find that the Plan satisfies the requirements of section
51.308(g)(4) by providing emissions information for NOX,
SO2, PM10, PM2.5, VOCs, and
NH3 broken down by type of sources and activities within the
state.
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\83\ Letter dated August 23, 2023 from Michael Benjamin,
Division Chief, Air Quality Planning and Science Division, to
Matthew Lakin, Acting Director, Air and Radiation Division, Region 9
(submitted electronically August 24, 2023).
\84\ 2023 California Regional Haze Technical Supplement.
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Pursuant to section 51.308(g)(5), CARB provided an assessment of
any significant changes in anthropogenic emissions within or outside
the state that have occurred since the period addressed in the most
recent plan, including whether or not these changes in anthropogenic
emissions were anticipated in that most recent plan, and whether they
have limited or impeded progress in reducing pollutant emissions and
improving visibility. CARB noted overall average emissions reductions
of 36 percent for NOX, 45 percent for SO2, 20
percent for ROG, and 28 percent for PM2.5 between the 2007-
2011 period and the 2014-2018 period. The EPA proposes to find the Plan
meets the requirements of section 51.308(g)(5).
G. 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, section 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 emissions 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. Section 51.308(i)(4) requires regional
haze plans to provide procedures for continuing consultation between
the State and FLMs on the implementation of the regional haze program,
including development and review of SIP revisions and progress reports,
and on the implementation of other programs having the potential to
contribute to impairment of visibility in mandatory Class I Federal
areas.
In Chapter 9 of the Plan, CARB indicates that it held multiple
informal consultation teleconferences with staff from the NPS and the
USFS during
[[Page 25944]]
development of its plan.\85\ CARB sent a draft of the Plan to the NPS,
FWS, and the USFS on February 9, 2022. CARB requested that FLM agencies
provide formal comments on the draft by April 11, 2022. The comments
received from federal land managers and CARB's responses to these
comments are provided in Appendix I of the Plan. Chapter 9 also
includes a discussion of CARB's procedures for continuing consultation
with stakeholders, including FLMs.
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\85\ Plan, p. 141.
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Therefore, the EPA proposes to find that the State satisfied the
FLM consultation requirements of CAA section 169A(d) and 40 CFR
51.308(i).
VII. Proposed Action
For the reasons discussed in this notice, under CAA section
110(k)(3), the EPA is proposing to fully approve the 2022 California
Regional Haze Plan as satisfying the regional haze requirements for the
second planning period contained in 40 CFR 51.308(f).
VIII. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the Act and applicable
federal regulations.\86\ Thus, in reviewing SIP submissions, the EPA's
role is to approve state choices, provided that they meet the criteria
of the Act. Accordingly, this proposed action merely proposes to
approve state law as meeting federal requirements and does not impose
additional requirements beyond those imposed by state law. For that
reason, this proposed action:
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\86\ 42 U.S.C. 7410(k); 40 CFR 52.02(a).
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Is not a significant regulatory action subject to review
by the Office of Management and Budget under Executive Orders 12866 (58
FR 51735, October 4, 1993);
Is not subject to Executive Order 14192 (90 FR 9065,
February 6, 2025) because SIP actions are exempt from review under
Executive Order 12866;
Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
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.);
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);
Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
Is not subject to Executive Order 13045 (62 FR 19885,
April 23, 1997) because it proposes to approve a state program;
Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001); and
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 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 dioxide, Ozone, Particulate matter, Sulfur oxides.
Dated: June 2, 2025.
Joshua F.W. Cook,
Regional Administrator, Region IX.
[FR Doc. 2025-11261 Filed 6-17-25; 8:45 am]
BILLING CODE 6560-50-P