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Proposed Rule2024-03529

Air Plan Approval; OR; Regional Haze Plan for the Second Implementation Period

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Published

February 23, 2024

Issuing agencies

Environmental Protection Agency

Abstract

The Environmental Protection Agency (EPA) is proposing to approve the regional haze state implementation plan revision submitted by Oregon on April 29, 2022, as supplemented on November 22, 2023, as satisfying applicable requirements under the Clean Air Act and the EPA's Regional Haze Rule for the program's second implementation period. The Oregon submission addressed 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 Oregon submission also addressed other applicable requirements for the second implementation period of the regional haze program. Upon final action, the Oregon submission will become part of the Oregon SIP.

Full Text

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<title>Federal Register, Volume 89 Issue 37 (Friday, February 23, 2024)</title>
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[Federal Register Volume 89, Number 37 (Friday, February 23, 2024)]
[Proposed Rules]
[Pages 13622-13652]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-03529]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R10-OAR-2023-0600; FRL-11593-01-R10]

Air Plan Approval; OR; Regional Haze 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 revision submitted
by Oregon on April 29, 2022, as supplemented on November 22, 2023, as
satisfying applicable requirements under the

[[Page 13623]]

Clean Air Act and the EPA's Regional Haze Rule for the program's second
implementation period. The Oregon submission addressed 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 Oregon submission also addressed other applicable
requirements for the second implementation period of the regional haze
program. Upon final action, the Oregon submission will become part of
the Oregon SIP.

DATES: Written comments must be received on or before March 25, 2024.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R10-
OAR-2023-0600 at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. For comments submitted at
<a href="http://regulations.gov">regulations.gov</a>, follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
<a href="http://regulations.gov">regulations.gov</a>. For either manner of submission, the EPA may publish
any comment received to its public docket. Do not submit electronically
any information you consider to be confidential business information or
other information the disclosure of which 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 confidential
business information or multimedia submissions, and general guidance on
making effective comments, please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.

FOR FURTHER INFORMATION CONTACT: Jeff Hunt, EPA Region 10, 1200 Sixth
Avenue, Suite 155, Seattle, WA 98101, at (206) 553-6357 or
<a href="/cdn-cgi/l/email-protection#c6aeb3a8b2e8aca3a0a086a3b6a7e8a1a9b0">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION: Throughout this document, the use of ``we''
and ``our'' means the EPA.

Table of Contents

I. Proposed Action
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. 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 State Implementation Plan
Requirements
F. Requirements for Periodic Reports Describing Progress Towards
the Reasonable Progress Goals
G. Requirements for State and Federal Land Manager Coordination
IV. The EPA's Evaluation of the Oregon Regional Haze Submission for
the Second Implementation Period
A. Background on the Oregon First Implementation Period SIP
Submission
B. The Oregon Second Implementation Period SIP Submission and
the EPA's Evaluation
C. Identification of Class I Areas
D. Calculations of Baseline, Current, and Natural Visibility
Conditions; Progress to Date; and the Uniform Rate of Progress
E. Long-Term Strategy for Regional Haze
a. The Oregon Long-Term Strategy
b. The EPA's Evaluation of the Oregon Long-Term Strategy
c. Additional Long-Term Strategy Requirements
F. Reasonable Progress Goals
G. Monitoring Strategy and Other Implementation Plan
Requirements
H. Requirements for Periodic Reports Describing Progress Towards
the Reasonable Progress Goals
I. Requirements for State and Federal Land Manager Coordination
V. Proposed Action
VI. Incorporation by Reference
VII. Statutory and Executive Order Reviews

I. Proposed Action

On April 29, 2022 and November 22, 2023, Oregon submitted a state
implementation plan (SIP) revision and supplement to address regional
haze for the second implementation period. Oregon made the submissions
to satisfy the Clean Air Act regional haze program requirements
pursuant to Clean Air Act sections 169A and 169B and the EPA's
implementing regulations in the Code of Federal Regulations (CFR) at 40
CFR 51.308. The EPA is proposing to find that the Oregon submissions
meet the applicable statutory and regulatory requirements and thus we
are proposing to approve the submissions into the SIP. We are also
proposing to approve, and incorporate by reference into the Oregon SIP
at 40 CFR part 52, subpart MM, specific regulatory provisions and
source-specific requirements included in the submissions. These
provisions are detailed in section V. of this preamble.

II. Background and Requirements for Regional Haze Plans

A. Regional Haze Background

In the 1977 Clean Air Act Amendments, Congress created a program
\1\ to protect visibility in the nation's mandatory class I Federal
areas, which include certain national parks and wilderness areas.\2\
Congress established 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.'' \3\ Congress further directed the EPA to promulgate
regulations to assure reasonable progress toward meeting this national
goal.\4\ On December 2, 1980, the EPA promulgated regulations to
address visibility impairment in mandatory class I Federal areas
(hereinafter referred to as ``Class I areas'') that is ``reasonably
attributable'' to a single source or small group of sources.\5\ These
regulations, codified at 40 CFR 51.300 through 51.307, represented the
first phase of the EPA's efforts to address visibility impairment. In
1990, Congress added section 169B to the Clean Air Act to further
address visibility impairment, specifically, impairment from regional
haze. The EPA subsequently promulgated the Regional Haze Rule on July
1, 1999 (64 FR 35714), codified at 40 CFR 51.308.\6\ These regional
haze regulations are a central component of the EPA's comprehensive
visibility protection program for Class I areas.
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\1\ Clean Air Act section 169A.
\2\ 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. Clean
Air Act 162(a). There are 156 mandatory Class I areas. The list of
areas to which the visibility protection program applies is set
forth in 40 CFR part 81, subpart D.
\3\ Clean Air Act section 169A(a)(1).
\4\ Clean Air Act section 169A(a)(4).
\5\ 45 FR 80084, December 2, 1980.
\6\ In addition to the generally applicable regional haze
provisions at 40 CFR 51.308, the EPA also promulgated regulations
specific to addressing regional haze visibility impairment in Class
I areas on the Colorado Plateau at 40 CFR 51.309. The latter
regulations are applicable only for specific jurisdictions' regional
haze plans submitted no later than December 17, 2007, and thus are
not relevant here.
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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

[[Page 13624]]

their precursors (e.g., sulfur dioxide (SO<INF>2</INF>), nitrogen
oxides (NO<INF>X</INF>), and, in some cases, volatile organic compounds
(VOC) and ammonia (NH<INF>3</INF>)). Fine particle precursors react in
the atmosphere to form fine particulate matter (PM<INF>2.5</INF>),
which impairs visibility by scattering and absorbing light. Visibility
impairment reduces the perception of clarity and color, as well as
visible distance.\7\
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\7\ 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 Regional Haze Rule. 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
to for expressing visibility and is measured in inverse megameters
(Mm-1). The EPA's Guidance on Regional Haze State
Implementation Plans for the Second Implementation Period (``2019
Guidance'') offers the flexibility for the use of light extinction
in certain cases. Light extinction can be simpler to use in
calculations than deciviews, since it is not a logarithmic function.
See, e.g., 2019 Guidance at 16, 19, <a href="https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period">https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period</a>. The EPA Office of Air Quality Planning and
Standards, Research Triangle Park (August 20, 2019). 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 Regional
Haze Rule 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.\8\ Under the Clean Air Act, each
SIP submission must contain ``a long-term (ten to fifteen years)
strategy for making reasonable progress toward meeting the national
goal.'' \9\ The initial round of SIP submissions also had to address
the statutory requirement that certain older, larger sources of
visibility impairing pollutants install and operate the best available
retrofit technology (BART).\10\ States' first regional haze SIPs were
due by December 17, 2007,\11\ with subsequent SIP submissions
containing updated long-term strategies originally due July 31, 2018,
and every ten years thereafter.\12\ The EPA established in the 1999
Regional Haze Rule that all states either have Class I areas within
their borders or ``contain sources whose emissions are reasonably
anticipated to contribute to regional haze in a Class I area'';
therefore, all states must submit regional haze SIPs.\13\
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\8\ Clean Air Act section 169A(b)(2). See also 40 CFR 51.308(b),
(f) (establishing submission dates for iterative regional haze SIP
revisions (64 FR 35714, 35768, July 1, 1999). The Regional Haze Rule
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).
\9\ Clean Air Act section 169A(b)(2)(B).
\10\ Clean Air Act section 169A(b)(2)(A); 40 CFR 51.308(d), (e).
\11\ 40 CFR 51.308(b).
\12\ 64 FR 35714, 35768, July 1, 1999.
\13\ 64 FR 35714, 35721, July 1, 1999. In addition to each of
the fifty states, the EPA also concluded that the Virgin Islands and
District of Columbia must also submit regional haze SIPs because
they either contain a Class I area or contain sources whose
emissions are reasonably anticipated to contribute regional haze in
a Class I area. See 40 CFR 51.300(b), (d)(3).
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Much of the focus in the first implementation period of the
regional haze program, which ran from 2007 through 2018, was on
satisfying states' BART obligations. First implementation period SIPs
were additionally required to contain long-term strategies for making
reasonable progress toward the national visibility goal, of which BART
is one component. The core required elements for the first
implementation period SIPs (other than BART) are laid out in 40 CFR
51.308(d). Those provisions required that states containing Class I
areas establish reasonable progress goals that are measured in
deciviews and reflect the anticipated visibility conditions at the end
of the implementation period including from implementation of states'
long-term strategies. The first planning period reasonable progress
goals were required to provide for an improvement in visibility for the
most impaired days over the period of the implementation plan and
ensure no degradation in visibility for the least impaired days over
the same period. In establishing the reasonable progress goals for any
Class I area in a state, the state was required to consider four
statutory factors: the costs of compliance, the time necessary for
compliance, the energy and non-air quality environmental impacts of
compliance, and the remaining useful life of any potentially affected
sources.\14\
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\14\ Clean Air Act section 169A(g)(1); 40 CFR 51.308(d)(1).
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States were also required to calculate baseline (using the five
year period of 2000-2004) and natural visibility conditions (i.e.,
visibility conditions without anthropogenic visibility impairment) for
each Class I area, and to calculate 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 known as the ``uniform
rate of progress'' and 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.\15\ The 1999 Regional
Haze Rule also provided that states' long-term strategies must include
the ``enforceable emissions limitations, compliance, schedules, and
other measures as necessary to achieve the reasonable progress goals.''
\16\ In establishing their long-term strategies, states are required to
consult with other states that also contribute to visibility impairment
in a given Class I area and include all measures necessary to obtain
their shares of the emission reductions needed to meet the reasonable
progress goals.\17\ The 1999 Regional Haze Rule also contains seven
additional factors states must consider in formulating their long-term
strategies,\18\ as well as provisions governing monitoring and other
implementation plan requirements.\19\ Finally, the 1999 Regional Haze
Rule required states to submit periodic progress reports--SIP revisions
due every five years that contain information on states' implementation
of their regional haze plans and an assessment of whether anything
additional is needed to make reasonable progress \20\--and to consult
with the Federal Land Manager(s) \21\ responsible for each Class I area

[[Page 13625]]

according to the requirements in Clean Air Act 169A(d) and 40 CFR
51.308(i).
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\15\ 40 CFR 51.308(d)(1)(i)(B), (d)(2). The EPA established the
uniform rate of progress framework in the 1999 Regional Haze Rule to
provide ``an equitable analytical approach'' to assessing the rate
of visibility improvement at Class I areas across the country. The
start point for the uniform rate of progress analysis is 2004 and
the endpoint was calculated based on the amount of visibility
improvement that was anticipated to result from implementation of
existing Clean Air Act programs over the period from the mid-1990s
to approximately 2005. Assuming this rate of progress would continue
into the future, the EPA determined that natural visibility
conditions would be reached in 60 years, or 2064 (60 years from the
baseline starting point of 2004). However, the EPA did not establish
2064 as the year by which the national goal must be reached. 64 FR
35714, 35731-32, July 1, 1999. That is, the uniform rate of progress
and the 2064 date are not enforceable targets, but are rather tools
that ``allow for analytical comparisons between the rate of progress
that would be achieved by the state's chosen set of control measures
and the [uniform rate of progress] URP.'' (82 FR 3078, 3084, January
10, 2017).
\16\ 40 CFR 51.308(d)(3).
\17\ 40 CFR 51.308(d)(3)(i), (ii).
\18\ 40 CFR 51.308(d)(3)(v).
\19\ 40 CFR 51.308(d)(4).
\20\ See 40 CFR 51.308(g), and (h).
\21\ The EPA's regulations define ``Federal Land Manager'' as
``the Secretary of the department with authority over the Federal
Class I area (or the Secretary's designee) or, with respect to
Roosevelt-Campobello International Park, the Chairman of the
Roosevelt-Campobello International Park Commission.'' 40 CFR 51.301.
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On January 10, 2017, the EPA promulgated revisions to the Regional
Haze Rule that apply for the second and subsequent implementation
periods (82 FR 3078). The 2017 rulemaking made several changes to the
requirements for regional haze SIPs to clarify States' obligations and
streamline certain regional haze requirements. The revisions to the
regional haze program for the second and subsequent implementation
periods focused on the requirement that States' SIPs contain long-term
strategies for making reasonable progress towards the national
visibility goal. The reasonable progress requirements as revised in the
2017 rulemaking (referred to here as the 2017 Regional Haze Rule
Revisions) are codified at 40 CFR 51.308(f). Among other changes, the
2017 Regional Haze Rule Revisions adjusted the deadline for States to
submit their second implementation period SIPs from July 31, 2018, to
July 31, 2021, clarified the order of analysis and the relationship
between reasonable progress goals and the long-term strategy, and
focused on making visibility improvements on the days with the most
anthropogenic visibility impairment, as opposed to the days with the
most visibility impairment overall. The EPA also revised requirements
of the visibility protection program related to periodic progress
reports and Federal Land Manager consultation. The specific
requirements applicable to second implementation period regional haze
SIP submissions are addressed in detail in the following paragraphs.
The EPA provided guidance to the states for their second
implementation period SIP submissions in the preamble to the 2017
Regional Haze Rule Revisions as well as in subsequent, stand-alone
guidance documents. In August 2019, the EPA issued ``Guidance on
Regional Haze State Implementation Plans for the Second Implementation
Period'' (``2019 Guidance'').\22\ On July 8, 2021, the EPA issued a
memorandum containing ``Clarifications Regarding Regional Haze State
Implementation Plans for the Second Implementation Period'' (``2021
Clarifications Memo'').\23\ Additionally, the EPA further clarified the
recommended procedures for processing ambient visibility data and
optionally adjusting the uniform rate of progress to account for
international anthropogenic and prescribed fire impacts in two
technical guidance documents: the December 2018 ``Technical Guidance on
Tracking Visibility Progress for the Second Implementation Period of
the Regional Haze Program'' (``2018 Visibility Tracking
Guidance''),\24\ and the June 2020 ``Recommendation for the Use of
Patched and Substituted Data and Clarification of Data Completeness for
Tracking Visibility Progress for the Second Implementation Period of
the Regional Haze Program'' and associated Technical Addendum (``2020
Data Completeness Memo'').\25\
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\22\ Guidance on Regional Haze State Implementation Plans for
the Second Implementation Period. <a href="https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period">https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period</a>. The EPA Office of Air Quality Planning and
Standards, Research Triangle Park (August 20, 2019).
\23\ Clarifications Regarding Regional Haze State Implementation
Plans for the Second Implementation Period. <a href="https://www.epa.gov/system/files/documents/2021-07/clarifications-regarding-regional-haze-state-implementation-plans-for-the-second-implementation-period.pdf">https://www.epa.gov/system/files/documents/2021-07/clarifications-regarding-regional-haze-state-implementation-plans-for-the-second-implementation-period.pdf</a>. The EPA Office of Air Quality Planning and Standards,
Research Triangle Park (July 8, 2021).
\24\ Technical Guidance on Tracking Visibility Progress for the
Second Implementation Period of the Regional Haze Program. <a href="https://www.epa.gov/visibility/technical-guidance-tracking-visibility-progress-second-implementation-period-regional">https://www.epa.gov/visibility/technical-guidance-tracking-visibility-progress-second-implementation-period-regional</a>. The EPA Office of
Air Quality Planning and Standards, Research Triangle Park.
(December 20, 2018).
\25\ Recommendation for the Use of Patched and Substituted Data
and Clarification of Data Completeness for Tracking Visibility
Progress for the Second Implementation Period of the Regional Haze
Program. <a href="https://www.epa.gov/visibility/memo-and-technical-addendum-ambient-data-usage-and-completeness-regional-haze-program">https://www.epa.gov/visibility/memo-and-technical-addendum-ambient-data-usage-and-completeness-regional-haze-program</a>. The EPA
Office of Air Quality Planning and Standards, Research Triangle Park
(June 3, 2020).
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As previously explained in the 2021 Clarifications Memo, the EPA
intends for the second implementation period of the regional haze
program to secure meaningful reductions in visibility impairing
pollutants that build on the significant progress states have achieved
to date. The EPA also recognizes that analyses regarding reasonable
progress are state-specific and that, based on states' and sources'
individual circumstances, what constitutes reasonable reductions in
visibility impairing pollutants will vary from state-to-state. While
there exist many opportunities for states to leverage both ongoing and
upcoming emission reductions under other Clean Air Act programs, the
EPA expects states to undertake rigorous reasonable progress analyses
that identify further opportunities to advance the national visibility
goal consistent with the statutory and regulatory requirements.\26\
This is consistent with Congress's determination that a visibility
protection program is needed in addition to the Clean Air Act's
National Ambient Air Quality Standards and Prevention of Significant
Deterioration programs, as further emission reductions may be necessary
to adequately protect visibility in Class I areas throughout the
country.\27\
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\26\ See generally 2021 Clarifications Memo.
\27\ See, e.g., H.R. Rep No. 95-294 at 205 (``In determining how
to best remedy the growing visibility problem in these areas of
great scenic importance, the committee realizes that as a matter of
equity, the national ambient air quality standards cannot be revised
to adequately protect visibility in all areas of the country.''),
(``the mandatory class I increments of [the PSD program] do not
adequately protect visibility in class I areas'').
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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. In order 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,\28\ which
include representation from state and tribal governments, the EPA, and
Federal Land Managers, were developed in the lead-up to the first
implementation period to address regional haze. Regional planning
organizations evaluate technical information to better understand how
emissions from State and Tribal lands 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 Regional Haze Rule.
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\28\ Regional planning organizations are sometimes also referred
to as ``multi-jurisdictional organizations''. For the purposes of
this document, the terms regional planning organizations and multi-
jurisdictional organizations are synonymous.
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Western Regional Air Partnership

The Western Regional Air Partnership (WRAP) \29\ is one of the five
regional planning organizations and functions as a voluntary
partnership of state, Tribal, Federal, and local air agencies whose
purpose is to understand current and evolving regional air quality
issues in the West. There are 15 member states in the WRAP, including
Oregon, in addition to 28 tribes and 30 local air

[[Page 13626]]

agency members.\30\ WRAP Federal partners are the EPA, National Parks
Service, Fish and Wildlife Service, Forest Service, and Bureau of Land
Management. The WRAP membership formed a workgroup to develop a
planning framework for state regional haze second planning period SIPs.
Based on emissions and monitoring data supplied by its membership, the
WRAP produced a technical system to support regional modeling of
visibility impacts at Class I areas across the west.\31\ The WRAP
Technical Support System consolidated air quality monitoring data,
meteorological and receptor modeling data analyses, emissions
inventories and projections, and gridded air quality/visibility
regional modeling results. The WRAP Technical Support System is
accessible by member states and allows for the creation of maps,
figures, and tables to export and use in state plan development, and
maintains the original source data for verification and further
analysis.
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\29\ The WRAP website may be found at <a href="https://www.wrapair2.org">https://www.wrapair2.org</a>.
\30\ The WRAP membership list may be found at <a href="https://www.wrapair2.org/membership.aspx">https://www.wrapair2.org/membership.aspx</a>.
\31\ Technical information may be found at <a href="https://www.wrapair2.org/RHPWG.aspx">https://www.wrapair2.org/RHPWG.aspx</a>.
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III. Requirements for Regional Haze Plans for the Second Implementation
Period

Under the Clean Air Act and the EPA's regulations, all 50 states,
the District of Columbia, and the United States (U.S.) Virgin Islands
are required to submit regional haze SIPs satisfying the applicable
requirements for the second implementation period of the regional haze
program by July 31, 2021. Each state's SIP must contain a long-term
strategy for making reasonable progress toward meeting the national
goal of remedying any existing and preventing any future anthropogenic
visibility impairment in Class I areas.\32\ 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 Sec. 51.308(f)(1) through (3) generally mirroring the
order of the steps in the reasonable progress analysis \33\ 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.\34\ For each Class I area within its borders, a state must
then calculate the baseline, current, and natural visibility conditions
for that area, as well as the visibility improvement made to date and
the uniform rate of progress.\35\ Each state having a Class I area and/
or emissions that may affect visibility in a Class I area must then
develop a long-term strategy that includes the enforceable emission
limitations, compliance schedules, and other measures that are
necessary to make reasonable progress in such areas. A reasonable
progress determination is based on applying the four factors in CAA
section 169A(g)(1) to sources of visibility-impairing pollutants that
the state has selected to assess for controls for the second
implementation period. Additionally, as further explained below, the
RHR at 40 CFR 51.308(f)(2)(iv) separately provides five ``additional
factors'' \36\ that states must consider in developing their long-term
strategies. See 40 CFR 51.308(f)(2). A state evaluates potential
emission reduction measures for those selected sources and determines
which are necessary to make reasonable progress. Those measures are
then incorporated into the state's long-term strategy. After a state
has developed its long-term strategy, it then establishes reasonable
progress goals 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 Clean Air Act. The reasonable progress
goals 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
reasonable progress goals are then compared to the baseline visibility
conditions and the uniform rate of progress 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.\37\
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\32\ Clean Air Act section 169A(b)(2)(B).
\33\ The EPA explained in the 2017 Regional Haze Rule Revisions
that we were adopting new regulatory language in 40 CFR 51.308(f)
that, unlike the structure in 51.308(d), ``tracked the actual
planning sequence.'' (82 FR 3091, January 10, 2017).
\34\ 40 CFR 51.308(f), (f)(2).
\35\ 40 CFR 51.308(f)(1).
\36\ The five ``additional factors'' for consideration in Sec.
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.
\37\ 40 CFR 51.308(f)(2) and (3).
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In addition to satisfying the requirements at 40 CFR 51.308(f)
related to reasonable progress, the regional haze SIP revisions for the
second implementation period must address the requirements in 40 CFR
51.308(g)(1) through (5) pertaining to periodic reports describing
progress towards the reasonable progress goals, 40 CFR 51.308(f)(5), as
well as requirements for Federal Land Manager consultation that apply
to all visibility protection SIPs and SIP revisions.\38\
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\38\ 40 CFR 51.308(i).
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A state must submit its regional haze SIP and subsequent SIP
revisions to the EPA according to the requirements applicable to all
SIP revisions under the Clean Air Act and the EPA's regulations.\39\
Upon EPA approval, a SIP is enforceable by the EPA and the public under
the Clean Air Act. If the EPA finds that a state fails to make a
required SIP revision, or if the EPA finds that a state's SIP is
incomplete or if disapproves the SIP, the EPA must promulgate a Federal
implementation plan (FIP) that satisfies the applicable
requirements.\40\
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\39\ See Clean Air Act section 169(b)(2); Clean Air Act section
110(a).
\40\ Clean Air Act section 110(c)(1).
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A. Identification of Class I Areas

The first step in developing a regional haze SIP is for a state to
determine which Class I areas, in addition to those within its borders,
``may be affected'' by emissions from within the state. In the 1999
Regional Haze Rule, the EPA determined that all states contribute to
visibility impairment in at least one Class I area and explained that
the statute and regulations lay out an ``extremely low triggering
threshold'' for determining ``whether States should be required to
engage in air quality planning and analysis as a prerequisite to
determining the need for control of emissions from sources within their
State.'' \41\
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\41\ 64 FR 35714, 35720-35722, July 1, 1999.
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A state must determine which Class I areas must be addressed by its
SIP by evaluating the total emissions of visibility impairing
pollutants from all sources within the state. While the Regional Haze
Rule does not require this evaluation to be conducted in any particular
manner, the EPA's 2019 Guidance provides recommendations for how such
an assessment might be accomplished, including by, where appropriate,
using the determinations previously made for the first implementation
period. 2019 Guidance at 8-9. In addition, the determination of which
Class I areas may be affected by a state's emissions is subject to the
requirement in 40 CFR 51.308(f)(2)(iii) to ``document the technical
basis, including modeling, monitoring, cost,

[[Page 13627]]

engineering, and emissions information, on which the State is relying
to determine the emission reduction measures that are necessary to make
reasonable progress in each mandatory Class I Federal area it
affects.''

B. Calculations of Baseline, Current, and Natural Visibility
Conditions; Progress to Date; and the Uniform Rate of Progress

As part of assessing whether a SIP submission for the second
implementation period is providing for reasonable progress towards the
national visibility goal, the Regional Haze Rule contains requirements
in 40 CFR 51.308(f)(1) related to tracking visibility improvement over
time. The requirements of this section apply only to states having
Class I areas within their borders; the required calculations must be
made for each such Class I area. The EPA's 2018 Visibility Tracking
Guidance \42\ provides recommendations to assist states in satisfying
their obligations under 40 CFR 51.308(f)(1); specifically, in
developing information on baseline, current, and natural visibility
conditions, and in making optional adjustments to the uniform rate of
progress to account for the impacts of international anthropogenic
emissions and prescribed fires.\43\
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\42\ The 2018 Visibility Tracking Guidance references and relies
on parts of the 2003 Tracking Guidance: ``Guidance for Tracking
Progress Under the Regional Haze Rule,'' which can be found at
<a href="https://www.epa.gov/sites/default/files/2021-03/documents/tracking.pdf">https://www.epa.gov/sites/default/files/2021-03/documents/tracking.pdf</a>.
\43\ 82 FR 3078, 3103-05, January 10, 2017.
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The Regional Haze Rule requires tracking of visibility conditions
on two sets of days: the clearest and the most impaired days.
Visibility conditions for both sets of days are expressed as the
average deciview index for the relevant five-year period (the period
representing baseline or current visibility conditions). The Regional
Haze Rule provides that the relevant sets of days for visibility
tracking purposes are the 20% clearest (the 20% of monitored days in a
calendar year with the lowest values of the deciview index) and 20%
most impaired days (the 20% of monitored days in a calendar year with
the highest amounts of anthropogenic visibility impairment).\44\ A
state must calculate visibility conditions for both the 20% clearest
and 20% most impaired days for the baseline period of 2000-2004 and the
most recent five-year period for which visibility monitoring data are
available (representing current visibility conditions).\45\ States must
also calculate natural visibility conditions for the clearest and most
impaired days,\46\ by estimating the conditions that would exist on
those two sets of days absent anthropogenic visibility impairment.\47\
Using all these data, states must then calculate, for each Class I
area, the amount of progress made since the baseline period (2000-2004)
and how much improvement is left to achieve in order to reach natural
visibility conditions.
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\44\ 40 CFR 51.301. This document also refers to the 20%
clearest and 20% most anthropogenically impaired days as the
``clearest'' and ``most impaired'' or ``most anthropogenically
impaired'' days, respectively.
\45\ 40 CFR 51.308(f)(1)(i), (iii).
\46\ The Regional Haze Rule at 40 CFR 51.308(f)(1)(ii) contains
an error related to the requirement for calculating two sets of
natural conditions values. The rule says ``most impaired days or the
clearest days'' where it should say ``most impaired days and
clearest days.'' This is an error that was intended to be corrected
in the 2017 Regional Haze Rule Revisions but did not get corrected
in the final rule language. This is supported by the preamble text
at 82 FR 3098, January 0, 2017: ``In the final version of 40 CFR
51.308(f)(1)(ii), an occurrence of ``or'' has been corrected to
``and'' to indicate that natural visibility conditions for both the
most impaired days and the clearest days must be based on available
monitoring information.''
\47\ 40 CFR 51.308(f)(1)(ii).
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Using the data for the set of most impaired days only, states must
plot a line between visibility conditions in the baseline period and
natural visibility conditions for each Class I area to determine the
uniform rate of progress--the amount of visibility improvement,
measured in deciviews, that would need to be achieved during each
implementation period in order to achieve natural visibility conditions
by the end of 2064. The uniform rate of progress is used in later steps
of the reasonable progress analysis for informational purposes and to
provide a non-enforceable benchmark against which to assess a Class I
area's rate of visibility improvement.\48\ Additionally, in the 2017
Regional Haze Rule Revisions, the EPA provided states the option of
proposing to adjust the endpoint of the uniform rate of progress to
account for impacts of anthropogenic sources outside the U.S. and/or
impacts of certain types of wildland prescribed fires. These
adjustments, which must be approved by the EPA, are intended to avoid
any perception that states should compensate for impacts from
international anthropogenic sources and to give states the flexibility
to determine that limiting the use of wildland-prescribed fire is not
necessary for reasonable progress.\49\
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\48\ Being on or below the uniform rate of progress is not a
``safe harbor''; i.e., achieving the uniform rate of progress does
not mean that a Class I area is making ``reasonable progress'' and
does not relieve a state from using the four statutory factors to
determine what level of control is needed to achieve such progress.
See, e.g., 82 FR 3078, 3093, January 10, 2017.
\49\ 82 FR 3078, 3107, January 10, 2017, footnote 116.
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The EPA's 2018 Visibility Tracking Guidance can be used to help
satisfy the 40 CFR 51.308(f)(1) requirements, including in developing
information on baseline, current, and natural visibility conditions,
and in making optional adjustments to the uniform rate of progress. In
addition, the 2020 Data Completeness Memo provides recommendations on
the data completeness language referenced in 40 CFR 51.308(f)(1)(i) and
provides updated natural conditions estimates for each Class I area.

C. Long-Term Strategy for Regional Haze

The core component of a regional haze SIP submission is a long-term
strategy that addresses regional haze in each Class I area within a
state's borders and each Class I area that may be affected by emissions
from the state. The long-term strategy ``must include the enforceable
emissions limitations, compliance schedules, and other measures that
are necessary to make reasonable progress, as determined pursuant to
(f)(2)(i) through (iv).'' \50\ The amount of progress that is
``reasonable progress'' is based on applying the four statutory factors
in Clean Air Act section 169A(g)(1) in an evaluation of potential
control options for sources of visibility impairing pollutants, which
is referred to as a ``four-factor'' analysis. The outcome of that
analysis is the emission reduction measures that a particular source or
group of sources needs to implement in order to make reasonable
progress towards the national visibility goal.\51\ Emission reduction
measures that are necessary to make reasonable progress may be either
new, additional control measures for a source, or they may be the
existing emission reduction measures that a source is already
implementing.\52\ Such measures must be represented by ``enforceable
emissions limitations, compliance schedules, and other measures''
(i.e., any additional compliance tools) in a state's long-term strategy
in its SIP.\53\
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\50\ 40 CFR 51.308(f)(2).
\51\ 40 CFR 51.308(f)(2)(i).
\52\ See 2019 Guidance at 43; 2021 Clarifications Memo at 8-10.
\53\ 40 CFR 51.308(f)(2).
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Section 51.308(f)(2)(i) provides the requirements for the four-
factor analysis. The first step of this analysis entails selecting the
sources to be evaluated for emission reduction measures; to this end,
states should

[[Page 13628]]

consider ``major and minor stationary sources or groups of sources,
mobile sources, and area sources'' of visibility impairing pollutants
for potential four-factor control analysis.\54\ A threshold question at
this step is which visibility impairing pollutants will be analyzed. As
the EPA previously explained, consistent with the first implementation
period, the EPA generally expects that each state will analyze at least
SO<INF>2</INF> and NO<INF>X</INF> in selecting sources and determining
control measures.\55\ A state that chooses not to consider at least
these two pollutants should demonstrate why such consideration would be
unreasonable.\56\
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\54\ 40 CFR 51.308(f)(2)(i).
\55\ See 2019 Guidance at 12, 2021 Clarifications Memo at 4.
\56\ 2021 Clarifications Memo at 4.
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While states have the option to analyze all sources, the 2019
Guidance explains that ``an analysis of control measures is not
required for every source in each implementation period,'' and that
``[s]electing a set of sources for analysis of control measures in each
implementation period is . . . consistent with the Regional Haze Rule,
which sets up an iterative planning process and anticipates that a
state may not need to analyze control measures for all its sources in a
given SIP revision.'' \57\ However, given that source selection is the
basis of all subsequent control determinations, a reasonable source
selection process ``should be designed and conducted to ensure that
source selection results in a set of pollutants and sources the
evaluation of which has the potential to meaningfully reduce their
contributions to visibility impairment.'' \58\
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\57\ 2019 Guidance at 9.
\58\ 2021 Clarifications Memo at 3.
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The EPA explained in the 2021 Clarifications Memo that each state
has an obligation to submit a long-term strategy that addresses the
regional haze visibility impairment that results from emissions from
within that state. Thus, source selection should focus on the in-state
contribution to visibility impairment and be designed to capture a
meaningful portion of the state's total contribution to visibility
impairment in Class I areas. A state should not decline to select its
largest in-state sources on the basis that there are even larger out-
of-state contributors.\59\
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\59\ Id. at 4. Similarly, in responding to comments on the 2017
Regional Haze Rule Revisions EPA explained that ``[a] state should
not fail to address its many relatively low-impact sources merely
because it only has such sources and another state has even more
low-impact sources and/or some high impact sources.'' Responses to
Comments on Protection of Visibility: Amendments to Requirements for
State Plans; Proposed Rule. 81 FR 26942, 26987-26988, May 4, 2016.
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Thus, 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.\60\ 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.'' \61\ The EPA has explained that the four-factor
analysis is an assessment of potential emission reduction measures
(i.e., control options) for sources; ``use of the terms `compliance'
and `subject to such requirements' in section 169A(g)(1) strongly
indicates that Congress intended the relevant determination to be the
requirements with which sources would have to comply in order to
satisfy the [Clean Air Act's] reasonable progress mandate.'' \62\ Thus,
for each source it has selected for four-factor analysis,\63\ a state
must consider a ``meaningful set'' of technically feasible control
options for reducing emissions of visibility impairing pollutants.\64\
The 2019 Guidance provides that ``[a] state must reasonably pick and
justify the measures that it will consider, recognizing that there is
no statutory or regulatory requirement to consider all technically
feasible measures or any particular measures. A range of technically
feasible measures available to reduce emissions would be one way to
justify a reasonable set.'' \65\
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\60\ The Clean Air Act provides that, ``[i]n determining
reasonable progress there shall be taken into consideration'' the
four statutory factors. Clean Air Act section 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.
\61\ Clean Air Act section 169A(g)(1).
\62\ 82 FR 3078, 3091, January 10, 2017.
\63\ ``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 Regional Haze Rule
requires states to evaluate individual sources. Rather, states have
``the flexibility to conduct four-factor analyses for specific
sources, groups of sources or even entire source categories,
depending on state policy preferences and the specific circumstances
of each state.'' 82 FR 3078, 3088, January 10, 2017. However, not
all approaches to grouping sources for four-factor analysis are
necessarily reasonable; the reasonableness of grouping sources in
any particular instance will depend on the circumstances and the
manner in which grouping is conducted. If it is feasible to
establish and enforce different requirements for sources or
subgroups of sources, and if relevant factors can be quantified for
those sources or subgroups, then states should make a separate
reasonable progress determination for each source or subgroup. 2021
Clarifications Memo at 7-8.
\64\ 82 FR 3078, 3088, January 10, 2017.
\65\ 2019 Guidance at 29.
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The EPA's 2021 Clarifications Memo provides further guidance on
what constitutes a reasonable set of control options for consideration:
``A reasonable four-factor analysis will consider the full range of
potentially reasonable options for reducing emissions.'' \66\ In
addition to add-on controls and other retrofits (i.e., new emission
reduction measures for sources), the EPA explained that states should
generally analyze efficiency improvements for sources' existing
measures as control options in their four-factor analyses, as in many
cases such improvements are reasonable given that they typically
involve only additional operation and maintenance costs. Additionally,
the 2021 Clarifications Memo provides that states that have assumed a
higher emission rate than a source has achieved or could potentially
achieve using its existing measures should also consider lower emission
rates as potential control options. That is, a state should consider a
source's recent actual and projected emission rates to determine if it
could reasonably attain lower emission rates with its existing
measures. If so, the state should analyze the lower emission rate as a
control option for reducing emissions.\67\ The EPA's recommendations to
analyze potential efficiency improvements and achievable lower emission
rates apply to both sources that have been selected for four-factor
analysis and those that have forgone a four-factor analysis on the
basis of existing ``effective controls.'' \68\
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\66\ 2021 Clarifications Memo at 7.
\67\ Ibid.
\68\ See 2021 Clarifications Memo at 5, 10.
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After identifying a reasonable set of potential control options for
the sources it has selected, a state then collects

[[Page 13629]]

information on the four factors with regard to each option identified.
The EPA has also explained that, in addition to the four statutory
factors, states have flexibility under the Clean Air Act and Regional
Haze Rule to reasonably consider visibility benefits as an additional
factor alongside the four statutory factors.\69\ The 2019 Guidance
provides recommendations for the types of information that can be used
to characterize the four factors (with or without visibility), as well
as ways in which states might reasonably consider and balance that
information to determine which of the potential control options is
necessary to make reasonable progress.\70\ The 2021 Clarifications Memo
contains further guidance on how states can reasonably consider modeled
visibility impacts or benefits in the context of a four-factor
analysis.\71\ Specifically, the EPA explained that while visibility can
reasonably be used when comparing and choosing between multiple
reasonable control options, it should not be used to summarily reject
controls that are reasonable given the four statutory factors.\72\
Ultimately, while states have discretion to reasonably weigh the
factors and to determine what level of control is needed, Sec.
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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\69\ See, e.g., Responses to Comments on Protection of
Visibility: Amendments to Requirements for State Plans; Proposed
Rule (81 FR 26942, May 4, 2016), Docket Number EPA-HQ-OAR-2015-0531,
U.S. Environmental Protection Agency at 186; 2019 Guidance at 36-37.
\70\ See 2019 Guidance at 30-36.
\71\ 2021 Clarifications Memo at 12-13, 14-15.
\72\ 2021 Clarifications Memo at 13.
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As explained above, 40 CFR 51.308(f)(2)(i) requires states to
determine the emission reduction measures for sources that are
necessary to make reasonable progress by considering the four factors.
Pursuant to 40 CFR 51.308(f)(2), measures that are necessary to make
reasonable progress towards the national visibility goal must be
included in a state's long-term strategy and in its SIP.\73\ If the
outcome of a four-factor analysis is a new, additional emission
reduction measure for a source, that new measure is necessary to make
reasonable progress towards remedying existing anthropogenic visibility
impairment and must be included in the SIP. If the outcome of a four-
factor analysis is that no new measures are reasonable for a source,
continued implementation of the source's existing measures is generally
necessary to prevent future emission increases and thus to make
reasonable progress towards the second part of the national visibility
goal: preventing future anthropogenic visibility impairment.\74\ That
is, when the result of a four-factor analysis is that no new measures
are necessary to make reasonable progress, the source's existing
measures are generally necessary to make reasonable progress and must
be included in the SIP. However, there may be circumstances in which a
state can demonstrate that a source's existing measures are not
necessary to make reasonable progress. Specifically, if a state can
demonstrate that a source will continue to implement its existing
measures and will not increase its emission rate, it may not be
necessary to have those measures in the long-term strategy in order to
prevent future emission increases and future visibility impairment. The
EPA's 2021 Clarifications Memo provides further explanation and
guidance on how states may demonstrate that a source's existing
measures are not necessary to make reasonable progress.\75\ If the
state can make such a demonstration, it need not include a source's
existing measures in the long-term strategy or its SIP.
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\73\ States may choose to, but are not required to, include
measures in their long-term strategies beyond just the emission
reduction measures that are necessary for reasonable progress. See
2021 Clarifications Memo at 16. For example, states with smoke
management programs may choose to submit their smoke management
plans to the EPA for inclusion in their SIPs but are not required to
do so. See, e.g., 82 FR 3078, 3108-3109, January 10, 2017
(requirement to consider smoke management practices and smoke
management programs under 40 CFR 51.308(f)(2)(iv) does not require
states to adopt such practices or programs into their SIPs, although
they may elect to do so).
\74\ See Clean Air Act section 169A(a)(1). See also 2021
Clarifications Memo at 8.
\75\ See 2021 Clarifications Memo at 8-10.
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As with source selection, the characterization of information on
each of the factors is also subject to the documentation requirement in
40 CFR 51.308(f)(2)(iii). The reasonable progress analysis, including
source selection, information gathering, characterization of the four
statutory factors (and potentially visibility), balancing of the four
factors, and selection of the emission reduction measures that
represent reasonable progress, is a technically complex exercise, but
also a flexible one that provides states with bounded discretion to
design and implement approaches appropriate to their circumstances.
Given this flexibility, 40 CFR 51.308(f)(2)(iii) plays an important
function in requiring a state to document the technical basis for its
decision making so that the public and the EPA can comprehend and
evaluate the information and analysis the state relied upon to
determine what emission reduction measures must be in place to make
reasonable progress. The technical documentation must include the
modeling, monitoring, cost, engineering, and emissions information on
which the state relied to determine the measures necessary to make
reasonable progress. This documentation requirement can be met through
the provision of and reliance on technical analyses developed through a
regional planning process, so long as that process and its output has
been approved by all state participants. In addition to the explicit
regulatory requirement to document the technical basis of their
reasonable progress determinations, states are also subject to the
general principle that those determinations must be reasonably moored
to the statute.\76\ That is, a state's decisions about the emission
reduction measures that are necessary to make reasonable progress must
be consistent with the statutory goal of remedying existing and
preventing future visibility impairment.
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\76\ See Arizona ex rel. Darwin v. U.S. EPA, 815 F.3d 519, 531
(9th Cir. 2016); Nebraska v. U.S. EPA, 812 F.3d 662, 668 (8th Cir.
2016); North Dakota v. EPA, 730 F.3d 750, 761 (8th Cir. 2013);
Oklahoma v. EPA, 723 F.3d 1201, 1206, 1208-10 (10th Cir. 2013); cf.
also National Parks Conservation Association v. EPA, 803 F.3d 151,
165 (3d Cir. 2015); Alaska Department of Environmental Conservation
v. EPA, 540 U.S. 461, 485, 490 (2004).
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The four statutory factors (and potentially visibility) are used to
determine what emission reduction measures for selected sources must be
included in a state's long-term strategy for making reasonable
progress. Additionally, the Regional Haze Rule at 40 CFR
51.308(f)(2)(iv) separately provides five ``additional factors'' \77\
that states must consider in developing their long-term strategies: (1)
emission reductions due to ongoing air pollution control programs,
including measures to address reasonably attributable visibility
impairment; (2) measures to reduce the impacts of construction
activities; (3) source retirement and replacement schedules; (4) basic
smoke management practices for prescribed fire used for agricultural
and wildland vegetation management purposes and smoke management
programs; and (5) the anticipated net effect on visibility due to

[[Page 13630]]

projected changes in point, area, and mobile source emissions over the
period addressed by the long-term strategy. The 2019 Guidance provides
that a state may satisfy this requirement by considering these
additional factors in the process of selecting sources for four-factor
analysis, when performing that analysis, or both, and that not every
one of the additional factors needs to be considered at the same stage
of the process.\78\ The EPA provided further guidance on the five
additional factors in the 2021 Clarifications Memo, explaining that a
state should generally not reject cost-effective and otherwise
reasonable controls merely because there have been emission reductions
since the first planning period owing to other ongoing air pollution
control programs or merely because visibility is otherwise projected to
improve at Class I areas. Additionally, states generally should not
rely on these additional factors to summarily assert that the state has
already made sufficient progress and, therefore, no sources need to be
selected or no new controls are needed regardless of the outcome of
four-factor analyses.\79\
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\77\ The five ``additional factors'' for consideration in 40 CFR
51.308(f)(2)(iv) are distinct from the four factors listed in Clean
Air Act section 169A(g)(1) and 40 CFR 51.308(f)(2)(i) that states
must consider and apply to sources in determining reasonable
progress.
\78\ See 2019 Guidance at 21.
\79\ 2021 Clarifications Memo at 13. In particular, the EPA
explained in the 2021 Clarifications Memo that states should not
rely on the considerations in 40 CFR 51.308(f)(2)(iv)(A) and (E) to
summarily assert that the state has already made sufficient progress
and therefore does not need to achieve any additional emission
reductions. 2021 Clarifications Memo at 13.
---------------------------------------------------------------------------

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.
Consultation allows for each state that impacts visibility in an area
to share whatever technical information, analyses, and control
determinations may be necessary to develop coordinated emission
management strategies. This coordination may be managed through inter-
and intra-regional planning organization consultation and the
development of regional emissions strategies; additional consultations
between states outside of regional planning organization processes may
also occur. If a state, pursuant to consultation, agrees that certain
measures (e.g., a certain emission limitation) are necessary to make
reasonable progress at a Class I area, it must include those measures
in its SIP.\80\ Additionally, the Regional Haze Rule requires that
states that contribute to visibility impairment at the same Class I
area consider the emission reduction measures the other contributing
states have identified as being necessary to make reasonable progress
for their own sources.\81\ If a state has been asked to consider or
adopt certain emission reduction measures, but ultimately determines
those measures are not necessary to make reasonable progress, that
state must document in its SIP the actions taken to resolve the
disagreement.\82\ The EPA will consider the technical information and
explanations presented by the submitting state and the state with which
it disagrees when considering whether to approve the state's SIP.\83\
Under all circumstances, a state must document in its SIP submission
all substantive consultations with other contributing states.\84\
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\80\ 40 CFR 51.308(f)(2)(ii)(A).
\81\ 40 CFR 51.308(f)(2)(ii)(B).
\82\ 40 CFR 51.308(f)(2)(ii)(C).
\83\ See id.; 2019 Guidance at 53.
\84\ 40 CFR 51.308(f)(2)(ii)(C).
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D. 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.'' \85\ Their primary purpose is to assist the public and the
EPA in assessing the reasonableness of states' long-term strategies for
making reasonable progress towards the national visibility goal.\86\
States in which Class I areas are located must establish two reasonable
progress goals, both in deciviews--one representing visibility
conditions on the clearest days and one representing visibility on the
most anthropogenically impaired days--for each area within their
borders.\87\ The two reasonable progress goals are intended to reflect
the projected impacts, on the two sets of days, of the emission
reduction measures the state with the Class I area, as well as all
other contributing states, have included in their long-term strategies
for the second implementation period.\88\ The reasonable progress goals
also account for the projected impacts of implementing other Clean Air
Act requirements, including non-SIP based requirements. Because
reasonable progress goals are the modeled result of the measures in
states' long-term strategies (as well as other measures required under
the Clean Air Act), they cannot be determined before states have
conducted their four-factor analyses and determined the control
measures that are necessary to make reasonable progress.\89\
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\85\ 82 FR 3078, 3091, January 10, 2017.
\86\ See 40 CFR 51.308(f)(3)(iii) and (iv).
\87\ 40 CFR 51.308(f)(3)(i).
\88\ Reasonable progress goals are intended to reflect the
projected impacts of the measures all contributing states include in
their long-term strategies. However, due to the timing of analyses
and of control determinations by other states, other on-going
emissions changes, a particular state's reasonable progress goals
may not reflect all control measures and emissions reductions that
are expected to occur by the end of the implementation period. The
2019 Guidance provides recommendations for addressing the timing of
reasonable progress goal calculations when states are developing
their long-term strategies on disparate schedules, as well as for
adjusting reasonable progress goals using a post-modeling approach.
2019 Guidance at 47-48.
\89\ 2021 Clarifications Memo at 6.
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For the second implementation period, the reasonable progress goals
are set for 2028. Reasonable progress goals are not enforceable
targets, 40 CFR 51.308(f)(3)(iii); rather, they ``provide a way for the
states to check the projected outcome of the [long-term strategy]
against the goals for visibility improvement.'' \90\ While states are
not legally obligated to achieve the visibility conditions described in
their reasonable progress goals, 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.'' Thus, states are
required to have emission reduction measures in their long-term
strategies that are projected to achieve visibility conditions on the
most impaired days that are better than the baseline period and shows
no degradation on the clearest days compared to the clearest days from
the baseline period. The baseline period for the purpose of this
comparison is the baseline visibility condition--the annual average
visibility condition for the period 2000-2004.\91\
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\90\ 2019 Guidance at 46.
\91\ 40 CFR 51.308(f)(1)(i), 82 FR 2078, 3097-98, January 10,
2017.
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So that reasonable progress goals may also serve as a metric for
assessing the amount of progress a state is making towards the national
visibility goal, the Regional Haze Rule requires states with Class I
areas to compare the 2028 reasonable progress goal for the most
impaired days to the corresponding point on the uniform rate of
progress 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 reasonable progress goal in 2028 is above the uniform
rate of progress (i.e., if visibility conditions are improving more
slowly than the rate

[[Page 13631]]

described by the uniform rate of progress), each state that contributes
to visibility impairment in the Class I area must demonstrate, based on
the four-factor analysis required under 40 CFR 51.308(f)(2)(i), that no
additional emission reduction measures would be reasonable to include
in its long-term strategy.\92\ 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 uniform
rate of progress 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.'' The 2019 Guidance provides
suggestions about how such a ``robust demonstration'' might be
conducted.\93\
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\92\ 40 CFR 51.308(f)(3)(ii).
\93\ 2019 Guidance at 50-51.
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The 2017 Regional Haze Rule, 2019 Guidance, and 2021 Clarifications
Memo also explain that projecting a reasonable progress goal that is on
or below the uniform rate of progress based on only on-the-books and/or
on-the-way control measures (i.e., control measures already required or
anticipated before the four-factor analysis is conducted) is not a
``safe harbor'' from the Clean Air Act's and Regional Haze Rule's
requirement that all states must conduct a four-factor analysis to
determine what emission reduction measures constitute reasonable
progress. The uniform rate of progress is a planning metric used to
gauge the amount of progress made thus far and the amount left before
reaching natural visibility conditions. However, the uniform rate of
progress is not based on consideration of the four statutory factors
and therefore cannot answer the question of whether the amount of
progress being made in any particular implementation period is
``reasonable progress.'' \94\
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\94\ 82 FR 3078, 3093, 3099-3100, January 10, 2017; 2019
Guidance at 22; 2021 Clarifications Memo at 15-16.
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E. Monitoring Strategy and Other State Implementation Plan Requirements

Section 51.308(f)(6) requires states to have certain strategies and
elements in place for assessing and reporting on visibility. Individual
requirements under this section apply either to states with Class I
areas within their borders, states with no Class I areas but that are
reasonably anticipated to cause or contribute to visibility impairment
in any Class I area, or both. A state with Class I areas within its
borders must submit with its SIP revision a monitoring strategy for
measuring, characterizing, and reporting regional haze visibility
impairment that is representative of all Class I areas within the
state. SIP revisions for such states must also provide for the
establishment of any additional monitoring sites or equipment needed to
assess visibility conditions in Class I areas, as well as reporting of
all visibility monitoring data to the EPA at least annually. 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.\95\ The IMPROVE monitoring data is
used to determine the 20% most anthropogenically impaired and 20%
clearest sets of days every year at each Class I area and tracks
visibility impairment over time.
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\95\ 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.\96\ Section 51.308(f)(6)(v) further requires
that all states' SIPs provide for a statewide inventory of emissions of
pollutants that are reasonably anticipated to cause or contribute to
visibility impairment in any Class I area; the inventory must include
emissions for the most recent year for which data are available and
estimates of future projected emissions. States must also include
commitments to update their inventories periodically. The inventories
themselves do not need to be included as elements in the SIP and are
not subject to EPA review as part of the EPA's evaluation of a SIP
revision.\97\ 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.\98\ Per
the 2019 Guidance, a state may note in its regional haze SIP that its
compliance with the Air Emissions Reporting Rule in 40 CFR part 51,
subpart A satisfies the requirement to provide for an emissions
inventory for the most recent year for which data are available. To
satisfy the requirement to provide estimates of future projected
emissions, a state may explain in its SIP how projected emissions were
developed for use in establishing reasonable progress goals for its own
and nearby Class I areas.\99\
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\96\ 40 CFR 51.308(f)(6)(ii), (iii).
\97\ See ``Step 8: Additional requirements for regional haze
SIPs'' in 2019 Regional Haze Guidance at 55.
\98\ 40 CFR 51.308(f)(6)(vi).
\99\ See ``Step 8: Additional requirements for regional haze
SIPs'' in 2019 Regional Haze Guidance at 55.
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Separate from the requirements related to monitoring for regional
haze purposes under 40 CFR 51.308(f)(6), the Regional Haze Rule also
contains a requirement at 40 CFR 51.308(f)(4) related to any additional
monitoring that may be needed to address visibility impairment in Class
I areas from a single source or a small group of sources. This is
called ``reasonably attributable visibility impairment.'' \100\ Under
this provision, if the EPA or the Federal Land Manager of an affected
Class I area has advised a state that additional monitoring is needed
to assess reasonably attributable visibility impairment, the state must
include in its SIP revision for the second implementation period an
appropriate strategy for evaluating such impairment.
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\100\ The EPA's visibility protection regulations define
``reasonably attributable visibility impairment'' as ``visibility
impairment that is caused by the emission of air pollutants from
one, or a small number of sources.'' 40 CFR 51.301.
---------------------------------------------------------------------------

F. 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.\101\ To this end, every state's SIP revision for the
second implementation period is required to describe the status of
implementation of all measures included in the state's long-term
strategy, including BART and reasonable progress emission reduction
measures from the first implementation period, and the resulting
emissions reductions.\102\
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\101\ 81 FR 26942, 26950, May 4, 2016; 82 FR 3078, 3119, January
10, 2017.
\102\ 40 CFR 51.308(g)(1) and (2).
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A core component of the progress report requirements is an
assessment of changes in visibility conditions on the

[[Page 13632]]

clearest and most impaired days. For second implementation period
progress reports, 40 CFR 51.308(g)(3) requires states with Class I
areas within their borders to first determine current visibility
conditions for each area on the most impaired and clearest days, 40 CFR
51.308(g)(3)(i)(B), and then to calculate the difference between those
current conditions and baseline (2000-2004) visibility conditions in
order to assess progress made to date.\103\ States must also assess the
changes in visibility impairment for the most impaired and clearest
days since they submitted their first implementation period progress
reports.\104\ Since different states submitted their first
implementation period progress reports at different times, the starting
point for this assessment will vary state by state.
---------------------------------------------------------------------------

\103\ 40 CFR 51.308(g)(3)(ii)(B).
\104\ 40 CFR 51.308(g)(3)(iii)(B), (f)(5).
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Similarly, states must provide analyses tracking the change in
emissions of pollutants contributing to visibility impairment from all
sources and activities within the state over the period since they
submitted their first implementation period progress reports.\105\
Changes in emissions should be identified by the type of source or
activity. Section 51.308(g)(5) also addresses changes in emissions
since the period addressed by the previous progress report and requires
states' SIP revisions to include an assessment of any significant
changes in anthropogenic emissions within or outside the state. This
assessment must include an explanation of whether these changes in
emissions were anticipated and whether they have limited or impeded
progress in reducing emissions and improving visibility relative to
what the state projected based on its long-term strategy for the first
implementation period.
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\105\ See 40 CFR 51.308(g)(4), (f)(5).
---------------------------------------------------------------------------

G. 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 Federal Land Manager or Federal Land
Managers; pursuant to that consultation, the state must include a
summary of the Federal Land Managers' conclusions and recommendations
in the notice to the public. Consistent with this statutory
requirement, the Regional Haze Rule also requires that states ``provide
the [Federal Land Manager] with an opportunity for consultation, in
person and at a point early enough in the State's policy analyses of
its long-term strategy emission reduction obligation so that
information and recommendations provided by the [Federal Land Manager]
can meaningfully inform the State's decisions on the long-term
strategy.'' \106\ Consultation that occurs 120 days prior to any public
hearing or public comment opportunity will be deemed ``early enough,''
but the Regional Haze Rule provides that in any event the opportunity
for consultation must be provided at least 60 days before a public
hearing or comment opportunity. This consultation must include the
opportunity for the Federal Land Managers to discuss their assessment
of visibility impairment in any Class I area and their recommendations
on the development and implementation of strategies to address such
impairment.\107\ In order for the EPA to evaluate whether Federal Land
Manager consultation meeting the requirements of the Regional Haze Rule
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 Federal Land Managers.\108\ Finally, a SIP revision
must provide procedures for continuing consultation between the state
and Federal Land Managers 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.\109\
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\106\ 40 CFR 51.308(i)(2).
\107\ Ibid.
\108\ 40 CFR 51.308(i)(3).
\109\ 40 CFR 51.308(i)(4).
---------------------------------------------------------------------------

IV. The EPA's Evaluation of the Oregon Regional Haze Submission for the
Second Implementation Period

A. Background on the Oregon First Implementation Period SIP Submission

Oregon submitted its regional haze SIP for the first implementation
period (2008 through 2018) on December 9, 2010, as supplemented on
February 01, 2011. The Clean Air Act required that the initial round of
regional haze plans include, among other things, a long-term strategy
for making reasonable progress and best available retrofit technology
requirements for certain older stationary sources, where
applicable.\110\ The EPA approved Oregon's first implementation period
SIP submission in two actions published July 5, 2011 (76 FR 38997) and
August 22, 2012 (77 FR 50611). Subsequently, on July 18, 2017, Oregon
submitted a five-year progress report and the EPA approved the progress
report on May 17, 2018 (83 FR 22853).\111\ In our action, we concluded
that Oregon made adequate progress in improving visibility as a result
of actions identified in the regional haze SIP. Specifically, based on
2010 through 2014 data, Oregon Class I areas attained the 2018
reasonable progress goals for improved visibility, except for one
IMPROVE monitor highly impacted by wildfire.\112\
---------------------------------------------------------------------------

\110\ The requirements for regional haze SIPs for the first
implementation period are contained in Clean Air Act section
169A(b)(2)(B) and 40 CFR 51.308(d) and (e). See also 40 CFR
51.308(b).
\111\ For details, please see the progress report in the docket
for the EPA's approval action on May 17, 2018 (83 FR 22853) at
<a href="https://www.regulations.gov">https://www.regulations.gov</a> under docket number EPA-R10-OAR-2017-
0482.
\112\ See Section III.B. Summary of Visibility Conditions of the
proposed rule. 83 FR 11927, 11930, March 19, 2018.
---------------------------------------------------------------------------

B. The Oregon Second Implementation Period SIP Submission and the EPA's
Evaluation

On April 29, 2022, and November 22, 2023, Oregon submitted
revisions to the SIP to address its regional haze obligations for the
second implementation period (2018 through 2028).\113\ The submissions
may be found in the docket for this action. Oregon made its April 29,
2022 submission available for public comment on August 27, 2021 through
November 1, 2021 \114\ and held a public hearing on October 27,
2021.\115\ The state received and responded to public comments and
included the comments and comment responses in the SIP submission.\116\
Oregon made its November 22, 2023 submission available for public
comment September 15, 2023 through October 21, 2023 and held a public
hearing on October 16, 2023.\117\ The State received and responded to
public comments and included the comments and comment responses in the
SIP submission.\118\
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\113\ Clean Air Act sections 169A and 40 CFR 51.308(f).
\114\ Notice of Proposed Rulemaking, August 27, 2021, included
in the docket for this action.
\115\ Staff report for the Oregon Environmental Quality
Commission Meeting February. 3-4, 2022, included in the docket for
this action.
\116\ Staff report for the Oregon Environmental Quality
Commission Meeting February. 3-4, 2022, Summary of Public Comments
and DEQ Responses.
\117\ Staff report for the Oregon Environmental Quality
Commission Meeting November 17, 2023, at page 15-16.
\118\ Staff report for the Oregon Environmental Quality
Commission Meeting November 17, 2023, at page 16.
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The following sections of this preamble describe the Oregon SIP
submission, including air quality

[[Page 13633]]

modeling conducted, source selection, four-factor analyses to determine
what emission reduction measures constitute reasonable progress for the
long-term strategy, assessment of progress made since the first
implementation period in reducing emissions of visibility impairing
pollutants, and the visibility improvement progress at Class I areas in
Oregon and other states impacted by Oregon sources. This preamble also
contains the EPA's evaluation of the Oregon SIP submission against the
requirements of the Clean Air Act and Regional Haze Rule for the second
implementation period of the regional haze program.

C. Identification of Class I Areas

Section 169A(b)(2) of the Clean Air Act 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 Regional Haze Rule
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.
Oregon Class I Areas
Oregon has 12 designated Class I areas, including Crater Lake
National Park, managed by the National Parks Service, and 11 wilderness
areas, managed by the U.S. Forest Service, or in the case of Hells
Canyon Wilderness Area, managed jointly by the U.S. Forest Service and
the Bureau of Land Management.\119\
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\119\ Section 169A of the Clean Air Act was established in 1977
to protect visibility in all wilderness areas over 5,000 acres and
all national parks over 6,000 acres. 156 such areas were designated
throughout the U.S.
---------------------------------------------------------------------------

Mt. Hood Wilderness Area
The Mt. Hood Wilderness Area consists of 47,160 acres on the slopes
of Mt. Hood in the northern Oregon Cascades. Wilderness elevations
range from 3,426 meters (m) (11,237 feet (ft.)) on the summit of Mt.
Hood down to almost 600 m (2,000 ft.) at the western boundary. It is
almost adjacent to the Portland, Oregon metropolitan area; the
westernmost boundary is about 20 kilometers (km) east of the Portland,
Oregon suburb of Sandy and 40 km from the heavily populated
metropolitan center, elevation 100 m (300 ft.). Visitation to the Mt.
Hood Wilderness Area is approximately 50,000 visitors a year, primarily
between May and October. Most visitors come from the Portland/Vancouver
area that has a population of approximately 2 million.
Mt. Jefferson Wilderness Area
The Mt. Jefferson Wilderness Area consists of 107,008 acres on the
crest of the Cascade Range in central Oregon. Its southern boundary is
a few km north of the northern boundary of the Mt. Washington
Wilderness and it extends 40 to 50 km north along the Cascade crest.
West of the crest, it consists primarily of the eastern side of the
North Santiam River headwaters basin that connects to the Willamette
Valley source region near Salem, Oregon, 100 km (60 miles (mi)) to the
west. East of the crest it occupies the western slopes of the Metolius
River drainage that connects eastern slopes with Deschutes River in
eastern Oregon. The highest elevation is 3,200 m (10,497 ft.) at the
summit of Mt. Jefferson in the northern part of the Wilderness. The
lowest Wilderness elevations are near 1,000 m (3,000 ft.) along the
western boundary in the North Santiam headwaters basin and along the
eastern boundary in the Metolius River basin.
Mt. Washington Wilderness Area
The Mt. Washington Wilderness Area consists of 52,516 acres on the
crest of the Cascade Range in central Oregon. Like the Three Sisters
Wilderness that it borders to the south, it includes headwaters
tributaries of the McKenzie River that flow west into the Willamette
Valley near Eugene and connect the Wilderness with that source region.
On the east side, eastern slopes of the Cascades descend to the
Deschutes River near Bend. The highest Wilderness elevation is 2,376 m
(7,794 ft.) at the summit of Mt. Washington. The lowest elevations are
near 900 m (3,000 ft.) in the upper headwaters basin of the McKenzie
River.
Three Sisters Wilderness Area
The Three Sisters Wilderness Area consists of 285,202 acres abreast
the crest of the Cascade Range in central Oregon. It includes
headwaters tributaries of the McKenzie River that flow west into the
Willamette Valley near Eugene and connect the Wilderness with that
source region. On the east side, streams flow east to the Deschutes
River near Bend. The highest crest elevation is 3,158 m (10,358 ft.) at
the summit of the South Sister. The lowest elevations are near 600 m
(2,000 ft.) where the South Fork of the McKenzie River exits the
Wilderness on the west boundary. This is about 500 m (1,600 ft.) above
the Willamette Valley at Eugene 70 km (40 mi) west.
Diamond Peak Wilderness Area
The 52,337 acre Diamond Peak Wilderness Area straddles the Cascade
Range 50 km (30 mi) north of Crater Lake National Park. The highest
crest elevation in the Wilderness is 2,666 m (8,744 ft.) at Diamond
Peak, which is also the highest summit in this region of the Cascade
Range. The lowest elevations are near 1,450 m (5,000 ft.) where streams
exit the Wilderness on the west side. On the east side, the Wilderness
is bordered by mountain lakes with elevations from 1,459 m to 1,693 m
(4,786 to 5,553 ft.). The area includes headwaters of the Middle Fork
of the Willamette River that flows to the Willamette Valley near
Eugene, elevation 100 m (300 ft.) and 90 km (60 mi) distant. Wilderness
elevations are thus some 1,400 m (4,600 ft.) above the Willamette
Valley floor. East of the Cascade crest, streams flow to the Deschutes
River in eastern Oregon.
Crater Lake National Park
Crater Lake National Park is the only national park in Oregon. The
park was established on May 22, 1902, and now consists of 183,315
acres. It is located in southwestern Oregon on the crest of the Cascade
Mountain range, 100 miles east of the Pacific Ocean. The crater's rim
elevations range from about 900 to 1,873 ft. above lake level. The
highest park elevation is 8,929 ft. at the peak of Mt. Scott, in the
eastern park area. The National Park includes headwaters of the Rogue
River that flows southwest towards the Medford/Grants Pass area, and
Sun Creek/Wood River that flows southeast to the Klamath Falls area.
Mountain Lakes Wilderness Area
The Mountain Lakes Wilderness Area, encompassing 23,071 acres, is a
relatively small Class I area in southern Oregon, 50 km (30 mi) south
of Crater Lake National Park. It consists of several peaks with a
highest elevation of 2,502 m (8,208 ft.) at the crest of Aspen Butte.
The lowest elevations are near 1,500 m (5,000 ft.). Primary drainages
are Varney Creek and Moss Creek that flow into the Upper Klamath Lake,
3 km northeast of the Wilderness boundary.
Gearhart Mountain Wilderness Area
The Gearhart Mountain Wilderness Area consists of 22,809 acres on
the flanks of Gearhart Mountain in south central Oregon, primarily the
northern

[[Page 13634]]

slope and eastern drainages of Gearhart Mountain, the dominant
topographic feature. Elevations range from near 5,900 ft. at the North
Fork of the Sprague River in the northern Wilderness to 8,364 ft. at
the summit of Gearhart Mountain.
Kalmiopsis Wilderness Area
The Kalmiopsis Wilderness Area consists of 179,700 acres and is
located in the Klamath Mountains of southwestern Oregon, part of the
coastal temperate rainforest zone that lies between the Pacific Ocean
and the east side of the coast ranges in northwestern U.S. and Canada.
Its western boundary is 20 to 25 km (12 to 15 mi) from the coast. Its
easternmost extent is about 40 km (25 mi) from the coast. Elevations
range from about 300 m (900 ft.) on the western boundary where the
Chetco River exits the Wilderness towards the Pacific Ocean 25 to 30
miles further west, to 1,554 m (5,098 ft.) on Pearsoll Peak on the
eastern Wilderness boundary. The terrain in the Wilderness is steep
canyons and long broad ridges. The Wilderness is mostly west of the
general crest of the coast range, thus exposed to precipitation caused
by lifting of eastward moving maritime air, primarily during the
winter. Precipitation ranges from 150 to 350 cm (60 to 140 inches (in))
annually, depending on elevation.
Strawberry Mountain Wilderness Area
The Strawberry Mountain Wilderness Area consists of 69,350 acres in
eastern Oregon, just east of John Day. The Wilderness comprises most of
the Strawberry Mountain Range. The terrain is rugged, with elevations
ranging from 1,220 m (4,000 ft.) to 2,755 m (9,038 ft.) at the summit
of Strawberry Mountain. The Wilderness borders the upper John Day River
valley to the north.
Eagle Cap Wilderness Area
The Eagle Cap Wilderness Area consists of 360,275 acres in
northeastern Oregon. The terrain is characterized by bare peaks and
ridges and U-shaped glaciated valleys. Elevations range from 5,000 ft.
in lower valleys to near 10,000 ft. at the highest mountain summits.
The Lostine and Minam Rivers flow north from the center of the
Wilderness towards Pendleton and the Columbia, 130 km northwest.
Hells Canyon Wilderness Area
The Hells Canyon Wilderness Area consists of 214,944 acres and is
located on the Oregon-Idaho border. The Snake River divides the
wilderness, with 131,133 acres in Oregon, and 83,811 acres in Idaho.
The Snake River canyon is the deepest river gorge in North America. The
higher terrain is located on the Oregon side. Popular Oregon-side
viewpoints are McGraw, Hat Point, and Somers Point.
Oregon Visibility Monitoring Network
Haze species in Oregon are measured and analyzed via the
Interagency Monitoring of Protected Visual Environments (IMPROVE)
network.\120\ Table 1 of this preamble lists the IMPROVE stations
representing visibility at Oregon Class I areas. Due to the remote
nature of some of the Class I areas, several areas share a common
IMPROVE station.
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\120\ IMPROVE website at <a href="http://vista.cira.colostate.edu/Improve">http://vista.cira.colostate.edu/Improve</a>.

Table 1--Oregon IMPROVE Stations and Class I Areas
----------------------------------------------------------------------------------------------------------------
Monitor ID Class I area Sponsor Years operated
----------------------------------------------------------------------------------------------------------------
MOHO............................... Mt. Hood Wilderness........ U.S. Forest Service... 2000-present.
THSI............................... Mt. Jefferson Wilderness... U.S. Forest Service... 1993-present.
Mt. Washington Wilderness..
Three Sisters Wilderness...
CRLA............................... Crater Lake National Park.. National Parks Service 1988-present.
Diamond Peak Wilderness....
Mountain Lakes Wilderness..
Gearhart Mountain
Wilderness.
KALM............................... Kalmiopsis Wilderness...... U.S. Forest Service... 2000-present.
STAR............................... Strawberry Mountain U.S. Forest Service... 2000-present.
Wilderness.
Eagle Cap Wilderness.......
HECA............................... Hells Canyon Wilderness U.S. Forest Service... 2000-present.
Area.
----------------------------------------------------------------------------------------------------------------

Identification of Class I Areas in Other States
The Oregon Department of Environmental Quality (ODEQ) used a Q/d
screening approach in developing a list of sources for potential four-
factor analysis, as discussed in more detail in section IV.E.a of this
preamble. Q/d is equal to the emissions (Q) in tons per year of
visibility-impairing pollutants (NO<INF>X</INF>, SO<INF>2</INF>, and
particulate matter less than 10 microns in diameter (PM<INF>10</INF>))
divided by the distance to a Class I area (d) in kilometers. The
resulting ratio is commonly used as a metric to assess a source's
potential visibility impacts on a particular Class I area. Importantly,
ODEQ used permitted emissions limits, called Plant Site Emissions
Limits (PSELs),\121\ for a facility in 2017 to calculate Q.
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\121\ PSELs are used to protect ambient air quality standards,
prevent significant deterioration of air quality, and to ensure
protection of visibility. Establishing such a limit is a mandatory
step in the Oregon permitting process. A PSEL is designed to be set
at the actual baseline emissions from a source plus approved
emissions increases and minus required emissions reductions. This
design is intended to maintain a more realistic emissions inventory.
Oregon uses a fixed baseline year of 1977 or 1978 (or a prior year
if more representative of normal operation) and factors in all
approved emissions increases and required emissions decreases since
baseline, to set the allowable emissions in the PSEL. Increases and
decreases since the baseline year do not affect the baseline, but
are included in the difference between baseline and allowable
emissions. Oregon's PSEL program is used, in part, to implement NSR
permitting. For major NSR, if a PSEL is calculated at a level
greater than an established significant emission rate (SER) over the
baseline actual emission rate, an evaluation of the air quality
impact and major NSR permitting are required. If not, the PSEL is
set without further review (a construction permit may also be
required). For minor NSR (State NSR), a similar calculation is
conducted. If the difference is greater than the SER, an air quality
analysis is required to evaluate whether ambient air quality
standards and increments are protected. The air quality analysis
results may require the source to reduce the airshed impact and/or
comply with a tighter emission limit. See 82 FR 14654, March 22,
2017, p. 14661. Oregon's PSEL requirements are codified at OAR 340,
Division 222. These requirements are approved into the Oregon SIP at
40 CFR 52.1970(c). Oregon imposes the PSEL requirements via its
major and minor new source review permitting programs at OAR 340,
Divisions 216 and 224. Thus, PSELs are applicable requirements
included in Title V operating permits for major stationary sources
in Oregon.
---------------------------------------------------------------------------

ODEQ determined that this approach based on permitted emissions or
potential to emit was more rigorous and environmentally protective than
relying

[[Page 13635]]

on actual 2017 emissions which could increase in the future. Using this
approach, ODEQ identified Oregon facilities with a Q/d >= 5 based on
PSELs as having potential visibility impacts on other states shown in
table 2 of this preamble.\122\ Based on the Q/d calculation, two
facilities, PGE Beaver/Port Westward I and Georgia Pacific-Wauna Mill
potentially impact visibility in Mount Rainier National Park,
Washington with Q/d values slightly higher than the most impacted
Oregon Class I area, Mount Hood Wilderness.\123\ All other facilities
have higher potential Q/d impacts on Oregon Class I areas than the
respective out-of-state Class I areas.\124\ Descriptions of the
controls imposed at the facilities listed in table 2 are contained in
section IV.E.b. of this preamble.
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\122\ While PGE Boardman's emissions in 2017 would have screened
the facility into four-factor analysis based on the facility PSELs,
and actual emissions, this facility closed operations in 2020. The
closure of this facility, the last coal-fired power plant in Oregon,
was a product of the first round of Regional Haze planning.
\123\ Please see the EPA's evaluation of 40 CFR
51.308(f)(3)(ii)(B) for Mount Rainier National Park under section
IV.F of this preamble.
\124\ April 29, 2022, Oregon SIP submission, Chapters 3.1. Q/d
screening process and 3.3. Impact of facilities in other states on
Oregon Class I areas.

Table 2--Impact of Oregon Facilities on Other States' Class I Areas
----------------------------------------------------------------------------------------------------------------
Closest non-
Facility name Oregon Class I Actual Q/ Q/d PSEL Nearest Oregon Actual Q/ Q/d PSEL
area d Class I area d
----------------------------------------------------------------------------------------------------------------
A Division of Cascades Holding Mount Adams 2.69 56.77 Mount Hood 3.02 63.72
US Inc. Wilderness, WA. Wilderness.
Ash Grove Cement Company...... Sawtooth 5.31 11.01 Eagle Cap 18.54 38.47
Wilderness, ID. Wilderness.
Beaver Plant/Port Westward I Mount Rainier NP, 3.75 40.15 Mount Hood 3.24 34.60
Plant. WA. Wilderness.
Biomass One, L.P.............. Marble Mountain 3.06 6.33 Mountain Lakes 4.77 9.86
Wilderness, CA. Wilderness.
Boise Cascade-Medford......... Marble Mountain 3.25 5.45 Mountain Lakes 4.19 7.02
Wilderness, CA. Wilderness.
Collins Products, L.L.C....... Lava Beds/ 2.43 5.48 Mountain Lakes 4.78 10.82
Schonchin Wilderness.
Wilderness, CA.
EVRAZ Inc. NA................. Mount Adams 2.44 8.14 Mount Hood 3.57 11.92
Wilderness, WA. Wilderness.
Georgia Pacific-Wauna Mill.... Mount Rainier NP, 17.94 31.48 Mount Hood 16.18 28.38
WA. Wilderness.
Georgia-Pacific-Toledo........ Mount Adams 4.64 12.04 Three Sisters 7.83 20.33
Wilderness, WA. Wilderness.
Halsey Pulp Mill.............. Mount Adams 3.11 8.32 Three Sisters 8.86 23.69
Wilderness, WA. Wilderness.
Klamath Cogeneration Project.. Lava Beds/ 3.66 8.69 Mountain Lakes 6.91 16.40
Schonchin Wilderness.
Wilderness, CA.
Oregon City Compressor Station Mount Adams 1.49 5.53 Mount Hood 3.64 13.49
Wilderness, WA. Wilderness.
Owens-Brockway Glass Container Mount Adams 6.13 11.85 Mount Hood 10.86 21.00
Inc. Wilderness, WA. Wilderness.
Roseburg Forest Products-- Redwood NP, CA... 10.39 16.70 Kalmiopsis 19.07 30.67
Dillard. Wilderness.
Willamette Falls Paper Company Mount Adams 1.75 12.23 Mount Hood 3.79 26.46
Wilderness, WA. Wilderness.
----------------------------------------------------------------------------------------------------------------

D. Calculations of Baseline, Current, and Natural Visibility
Conditions; Progress to Date; and the Uniform Rate of Progress

Section 51.308(f)(1) requires states to determine the following for
``each mandatory Class I Federal area located within the State:''
baseline visibility conditions for the most impaired and clearest days,
natural visibility conditions for the most impaired and clearest days,
progress to date for the most impaired and clearest days, the
differences between current visibility conditions and natural
visibility conditions, and the uniform rate of progress. This section
also provides the option for states to propose adjustments to the
uniform rate of progress line for a Class I area to account for
visibility impacts from anthropogenic sources outside the U.S. and/or
the impacts from wildland prescribed fires that were conducted for
certain, specified objectives.\125\
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\125\ 40 CFR 51.308(f)(1)(vi)(B).
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Tracking Visibility in Oregon
Oregon's SIP submission addresses baseline, current and natural
visibility conditions for each of these IMPROVE stations as required by
the 2017 Regional Haze Rule and the EPA's technical guidance on
tracking visibility progress. ODEQ reviewed visibility data from 2000
through 2018 and determined that current visibility at all Class I
areas for both the clearest and most impaired days has improved since
the baseline period. In addition, all areas have met the uniform rate
of progress (URP) for 2018.\126\ Additionally, many Class I areas such
as the Mt. Hood, Strawberry Mountain, Eagle Cap, and Hells Canyon
wilderness areas are already meeting the 2028 URP for the Most Impaired
Days (MID) based on current 2014-2018 monitoring data. Oregon did not
choose to adjust its URP for international anthropogenic impacts or to
account for the impacts of wildland prescribed fires resulting in a
more stringent, environmentally protective URP glidepath as discussed
in section IV.F. of this preamble.
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\126\ April 29, 2022 Oregon SIP submission. Tables 2-6 and 2-7.
\127\ ODEQ used data drawn from ``Availability of Modeling Data
and Associated Technical Support Document for the EPA's Updated 2028
Visibility Air Quality Modeling'' (EPA 2019) with corrected data as
applicable from the June 2020 EPA Memo, ``Technical addendum
including updated visibility data through 2018 for the memo titled
`Recommendation for the Use of Patched and Substituted Data and
Clarification of Data Completeness for Tracking Visibility Progress
for the Second Implementation Period of the Regional Haze Program.''

Table 3--Haze Indices (Deciviews) for Oregon IMPROVE Stations \127\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Current
Monitor ID Class I area Baseline 2018 URP conditions 2028 URP Natural
2000-2004 2014-2018 2064
--------------------------------------------------------------------------------------------------------------------------------------------------------
Most Impaired Days
--------------------------------------------------------------------------------------------------------------------------------------------------------
MOHO.............................. Mt. Hood Wilderness 12.10 10.81..................... 9.27 9.90...................... 6.59
Area.
THSI.............................. Mt. Jefferson, Mt. 12.80 11.52..................... 11.28 10.60..................... 7.30
Washington, and
Three Sisters
Wilderness Areas.

[[Page 13636]]

CRLA.............................. Crater Lake National 9.36 8.38...................... 7.98 7.70...................... 5.16
Park; Diamond Peak,
Mountain Lakes, and
Gearhart Mountain
Wilderness Areas.
KALM.............................. Kalmiopsis Wilderness 13.34 12.04..................... 11.97 11.13..................... 7.78
Area.
STAR.............................. Strawberry Mountain 14.53 12.68..................... 11.19 11.35..................... 6.58
and Eagle Cap
Wilderness Areas.
HECA.............................. Hells Canyon 16.51 14.19..................... 12.33 12.53..................... 6.57
Wilderness Area.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Clearest Days
--------------------------------------------------------------------------------------------------------------------------------------------------------
MOHO.............................. Mt. Hood Wilderness 2.17 Not applicable............ 1.39 Not applicable............ 0.88
Area.
THSI.............................. Mt. Jefferson, Mt. 3.04 NA........................ 2.61 NA........................ 1.86
Washington, and
Three Sisters
Wilderness Areas.
CRLA.............................. Crater Lake National 1.69 NA........................ 1.05 NA........................ 0.10
Park; Diamond Peak,
Mountain Lakes, and
Gearhart Mountain
Wilderness Areas.
KALM.............................. Kalmiopsis Wilderness 6.27 NA........................ 5.90 NA........................ 3.70
Area.
STAR.............................. Strawberry Mountain 4.49 NA........................ 2.79 NA........................ 1.48
and Eagle Cap
Wilderness Areas.
HECA.............................. Hells Canyon 5.52 NA........................ 4.00 NA........................ 2.52
Wilderness Area.
--------------------------------------------------------------------------------------------------------------------------------------------------------

The EPA is proposing to find that Oregon has submitted a regional
haze plan that meets the requirements of 40 CFR 51.308(f)(1) related to
the calculations of baseline, current, and natural visibility
conditions; progress to date; and the uniform rate of progress for the
second implementation period.

E. Long-Term Strategy for Regional Haze

a. The Oregon Long-Term Strategy
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.\128\ As explained in the background discussion in section II. of
this preamble, reasonable progress is achieved when all states
contributing to visibility impairment in a Class I area are
implementing the measures determined--through application of the four
statutory factors to sources of visibility impairing pollutants--to be
necessary to make reasonable progress.\129\ Each state's long-term
strategy must include the enforceable emission limitations, compliance
schedules, and other measures that are necessary to make reasonable
progress.\130\ All new (i.e., additional) measures that are the outcome
of four-factor analyses are necessary to make reasonable progress and
must be in the long-term strategy. If the outcome of a four-factor
analysis and other measures necessary to make reasonable progress is
that no new measures are reasonable for a source, that source's
existing measures are necessary to make reasonable progress, unless the
state can demonstrate that the source will continue to implement those
measures and will not increase its emission rate. Existing measures
that are necessary to make reasonable progress must also be in the
long-term strategy. In developing its long-term strategies, a state
must also consider five additional factors.\131\ As part of its
reasonable progress determinations, the state must describe the
criteria used to determine which sources or group of sources were
evaluated (i.e., subjected to four-factor analysis) for the second
implementation period and how the four factors were taken into
consideration in selecting the emission reduction measures for
inclusion in the long-term strategy.\132\
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\128\ Clean Air Act section 169A(b)(2)(B).
\129\ 40 CFR 51.308(f)(2)(i).
\130\ 40 CFR 51.308(f)(2).
\131\ 40 CFR 51.308(f)(2)(iv).
\132\ 40 CFR 51.308(f)(2)(iii).
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The following paragraphs summarize how the Oregon submissions
addressed the requirements of 40 CFR 51.308(f)(2)(i). The EPA's
evaluation of the Oregon submission is contained in section IV.E.b. of
this preamble. The Oregon submission includes analysis and modeling
conducted by the State, the EPA and the WRAP, a narrative description
of the State's long-term strategy, and enforceable emissions
limitations embodied in State administrative orders and permits.\133\
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\133\ April 29, 2022 Oregon SIP submission, Chapter 2.5.1
Estimated future projected emissions.
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States may rely on technical information developed by the regional
planning organizations of which they are members to select sources for
four-factor analysis and to conduct that analysis, as well as to
satisfy the documentation requirements under 40 CFR 51.308(f). Where a
regional planning organization has performed source selection and/or
four-factor analyses (or considered the five additional factors in 40
CFR 51.308(f)(2)(iv)) for its member states, those states may rely on
the regional planning organization's analyses for the purpose of
satisfying the requirements of 40 CFR 51.308(f)(2)(i) so long as the
states have a reasonable basis to do so and all state participants in
the regional planning organization process have approved the technical
analyses.\134\ States may also satisfy the requirement of 40 CFR
51.308(f)(2)(ii) to engage in interstate consultation with other states
that have emissions that are reasonably anticipated to contribute to
visibility impairment in a given Class I area under the auspices of
intra- and inter-regional planning organization engagement.
---------------------------------------------------------------------------

\134\ 40 CFR 51.308(f)(3)(iii).
---------------------------------------------------------------------------

The WRAP is the regional planning organization to which Oregon
belongs. The WRAP coordinated technical services, modeling, data
management, and consulting during the second planning period. The WRAP
developed technical tools, emission inventories, and air quality
modeling with input and involvement from states in the region. Oregon
has participated actively in the WRAP and used WRAP technical products
to help develop the Oregon submissions.
In the submissions, Oregon conducted technical analyses to identify
sources and source categories with the largest potential to contribute
to visibility impairment at Class I areas in Oregon and other states.
Based on the composition of regional haze forming pollutants at the
IMPROVE stations, ODEQ determined that the majority of U.S.
anthropogenic contribution to

[[Page 13637]]

regional haze in Oregon Class I areas is ammonium nitrate. This varies
seasonally and by monitor.\135\ Statewide, NO<INF>X</INF> emissions are
primarily from mobile sources, at about 80% of the inventory, with
another 13% of the inventory coming from fuel combustion from area and
stationary sources.\136\ At some monitors, such as the IMPROVE stations
in the Cascades (THIS and CRLA) and Kalmiopsis (KALM), ammonium sulfate
is a proportionally larger contributor to regional haze formation. ODEQ
determined the ammonium sulfate contribution is primarily from
international anthropogenic sources and is projected to decrease by 77%
due to new standards for international marine shipping fuels which
became effective in 2020.\137\ Specifically, in 2010, the International
Marine Organization (IMO) established emission standards for vessels
operating in designated waters off the coast of North America. MARPOL
Annex VI is codified at 33 U.S.C. 1901 et seq. Pursuant to 33 U.S.C.
1907, it is unlawful to act in violation of the MARPOL Protocol. The
North American Emissions Control Area (ECA) covers most coastal areas
of the United States. Vessels operating in the area must burn low
sulfur marine fuel, 1,000 ppm sulfur content (0.10% sulfur by weight).
In addition, as of January 1, 2020, the IMO limited sulfur in fuel for
ships operating outside designated ECAs to 5,000 ppm sulfur content
(0.50% sulfur by weight). This limit represents a substantial reduction
from the prior IMO limit of 35,000 ppm sulfur content (3.5% sulfur by
weight). Fuel sulfur limits are codified at 40 CFR part 1043. See 84 FR
69335, 69336 (December 18, 2019). The levels of organic mass and
elemental carbon, likely from wildfire, prescribed burning, and
anthropogenic and biogenic sources of volatile organic compounds vary
at all Oregon IMPROVE stations from 2000 to 2018 but show no
significant trend.\138\
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\135\ April 29, 2022 Oregon SIP submission, Chapter 2.4
Pollutant Components of Visibility Impairment.
\136\ April 29, 2022 Oregon SIP submission, Chapter 2.3
Emissions Inventory Analysis.
\137\ International Marine Organization. 2020. A Breath of Fresh
Air. <a href="https://wwwcdn.imo.org/localresources/en/MediaCentre/HotTopics/Documents/Sulphur%202020%20infographic%202%20page.pdf">https://wwwcdn.imo.org/localresources/en/MediaCentre/HotTopics/Documents/Sulphur%202020%20infographic%202%20page.pdf</a>.
\138\ April 29, 2022 Oregon SIP submission, Chapter 2.4
Pollutant Components of Visibility Impairment.
---------------------------------------------------------------------------

In addition to selecting and evaluating stationary sources for
four-factor analysis, Oregon also used EPA emissions inventory data
from 2017 to review emissions from mobile sources such as nonroad
vehicles (e.g., construction, agriculture, lawn and garden,
recreational equipment) and onroad vehicles (e.g. commercial trucks,
passenger cars and trucks), as well as agriculture, fugitive dust,
marine shipping, oil and gas, prescribed fires, and railroads. The
submissions address these sectors and their potential to contribute to
visibility impairment in Chapter 2.3. Emissions Inventory Analysis and
Chapter 4 Long-term Strategy.
With respect to analyzing stationary sources, Oregon used a Q/d
methodology to select sources for evaluation under the four statutory
factors. This methodology does not take into consideration topography,
transport direction/pathway and dispersion, and photochemical
processes. However, it is an adequate tool for source selection and is
consistent with the EPA guidance. Specifically, Oregon's submission
determined ``Q/d'' where ``Q'' is a source's emissions and ``d'' is the
distance from the source to the nearest Class I area. Oregon identified
permitted point sources by their Q/d values, calculated using the sum
of all emissions of sulfur dioxide, nitrogen oxides and particulate
matter less than 10 microns in diameter (as measured in tons per year),
divided by the distance to a Class I area (measured in kilometers from
the facility to the nearest boundary of the Class I area) for all Class
I areas within 400 km of the source. Rather than using actual emissions
to screen facilities in, Oregon was more conservative and used
permitted emissions, called Plant Site Emissions Limits (PSELs) to
effectively screen in more sources than would otherwise have been
identified.\139\
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\139\ Save for certain exceptions, PSELs are included in all Air
Contaminant Discharge Permits (ACDP) and Title V Operating Permits
issued to sources in Oregon. See OAR 340-222-0020. This program is
approved into the Oregon SIP. 40 CFR 52.1970(c). Oregon establishes
PSELs for multiple pollutants, including SO<INF>2</INF>,
NO<INF>X</INF>, PM<INF>10</INF>, and PM<INF>2.5</INF>. Id. Sources
are required to monitor pollutant emissions and comply with the
PSELs. 340-222-0080. PSELs serve as a basis for, among other things,
assuring compliance with ambient air quality standards and
Prevention of Significant Deterioration increments. OAR 340-222-
0020. ODEQ sets PSELs based on a variety of factors; in general,
PSELs are set at levels above the projected actual or actual
emissions of the source. OAR 340-222-0041; 0042.
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As discussed in more detail in section IV.E.b of this preamble,
Oregon selected 32 sources for review using the Q/d screening
methodology. Of these 32 sources, several incorporated enforceable
emissions limits into their permits or in agreed orders resulting in
PSELs below the screening threshold, and several had recently imposed
controls already in place, with the remaining 23 sources conducting
four-factor analyses. ODEQ reviewed the four-factor analyses submitted
by the sources and found that 6 of the sources that additional controls
were above the $10,000 cost per ton reduction threshold established by
ODEQ. For the remaining 17 sources, ODEQ determined that additional
controls might be cost effective and initiated a second round of review
evaluating 43 emissions units and a total of 62 control devices. During
this second round of review, an additional 4 sources incorporated
facility-wide enforceable emissions limits effectively lowering PSELs
below the screening threshold, and ODEQ negotiated permit modifications
or agreed orders to install control devices or other emissions
reductions at the remaining 13 facilities described in more detail in
section IV.E.b. of this preamble.
After reviewing the submissions, the EPA proposes to determine that
Oregon's long-term strategy includes the enforceable emissions
limitations, compliance schedules, and other measures necessary to make
reasonable progress. By extension, the EPA proposes to determine that
Oregon's selection of sources for evaluation under the four statutory
factors was reasonable and consistent with the requirements of the RHR
and proposes to determine that Oregon determined the controls necessary
for reasonable progress based on a reasonable consideration of the four
factors, as described in the evaluation below.
b. The EPA's Evaluation of the Oregon Long-Term Strategy
The EPA is proposing to find that Oregon has satisfied the
requirements of 40 CFR 51.308(f)(2)(i) related to evaluating sources
and determining the emission reduction measures that are necessary to
make reasonable progress by considering the four statutory factors. The
EPA is proposing to find that Oregon has satisfied the four-factor
analysis requirement through its evaluation and actions documented in
the Oregon regional haze plan for the second planning period. Section
51.308(f)(2)(i) requires states to evaluate and determine the emission
reduction measures that are necessary to make reasonable progress by
considering the four statutory factors to sources in a control
analysis. As laid out in further detail in the following paragraphs of
this preamble, the EPA is proposing to find that the Oregon submission,
as supplemented, satisfies the requirement of 40 CFR 51.308(f)(2)(i).
The emission reduction measures that are necessary to

[[Page 13638]]

make reasonable progress must be included in the long-term strategy,
i.e., in the Oregon SIP. 40 CFR 51.308(f)(2).
Division 223 Regional Haze Rules
On May 28, 2021, Oregon opened public comment on revisions to the
Division 223 Regional Haze rules to update the provisions for the
second regional haze planning period.\140\ The Oregon Environmental
Quality Commission adopted the revisions to the Division 223 Regional
Haze rules at its July 22-23, 2021 meeting, and the rules became
effective July 23, 2021.\141\ A detailed redline/strikeout of the rule
revisions is included in the docket for this action.\142\ The revisions
removed outdated BART provisions from the first planning period,
including source-specific requirements in Oregon Administrative Rules
(OAR) 340-223-0040 for the Amalgamated Sugar Company which ceased
operation on December 9, 2010, and closed permanently in September
2016.\143\ The revisions also repealed outdated BART provisions in OAR
340-223-0030 through 340-223-0080 for the Portland General Electric
(PGE) coal-fired power plant in Boardman which ceased operation on
October 15, 2020, pursuant to the requirements of the regional haze
plan for the first implementation period. Documentation of the closure
of the coal-fired power plant is included in the docket for this
action.\144\
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\140\ 016_4.1.2 SOS.Notice.FilingReceipt.pdf included in the
docket for this action.
\141\ 018_4.2.2 SOS.Filing.Receipt.DEQ_14-2021.pdf included in
the docket for this action.
\142\ 004_3.1 RHSIP2021.Rules_.doc included in the docket for
this action.
\143\ April 29, 2022 Oregon SIP submission, Chapter 2.1.1 Status
of implementation of control measures included in the original
regional haze SIP.
\144\ See 200_boardman closure_25-0016-TV-01_AR_2020,
201_boardman closure_25-0016-TV-01_AR_2021, 202_boardman
closure_AIRS_AFS Search _US EPA, 203_2022 PSD permit_boardman
carty_25-0016-ST-02_PM_2022_3.
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In addition to removing outdated provisions, Oregon added new rule
provisions to implement the regional haze program for the second
implementation period. OAR 340-223-0100 Screening Methodology for
Sources for Round II of Regional Haze established the screening
methodology for stationary sources in the regional haze second planning
period. Pursuant to this rulemaking sources were required to undergo
review if the source's Q/d was greater than 5, where Q equals the sum
of the source's PSELs for NO<INF>X,</INF> SO<INF>2</INF>, and
PM<INF>10</INF>.
OAR 340-223-0110 Options for Compliance with Round II of Regional
Haze imposed the obligation on screened sources to conduct four-factor
analyses and established the process for imposition of controls
determined by ODEQ to be cost effective based on those four-factor
analyses, using a cost-effectiveness threshold of $10,000 or less per
ton of reductions for any single or combination of regional haze
pollutants. Specifically, OAR 340-223-0110(1) requires each source
screened into review to submit a four-factor analysis and install
controls determined by ODEQ to be cost effective following ODEQ's
adjustment and review of the four-factor analysis. OAR 340-223-0110(2)
allows alternative compliance options under an agreed order with ODEQ
(stipulated agreement and final order or SAFO) as summarized below:
<bullet> Accept federally enforceable reductions of combined plant
site emission limits of regional haze pollutants to bring the source's
Q/d below 5.00. A source may take a PSEL reduction below the generic
PSEL to achieve an overall PSEL of regional haze pollutants below a Q/d
of 5.00. A source's Q/d will be considered to be brought below 5.00
when Q/d is below 5.00 using the calculation in OAR 340-223-0100(2),
except that the Q factor shall be calculated by adding the plant site
emission limits for regional haze pollutants as stated in the
stipulated agreement and final order;
<bullet> Install controls identified by the source in a four-factor
analysis as cost-effective for that source for reducing regional haze
pollutants. ODEQ must agree that the controls identified will result in
the greatest cost-effective emissions reduction at the identified
emissions unit and ODEQ must establish a timeline for installation of
those controls that is the fastest practicable timeline for
installation of the identified controls and that is no later than July
31, 2026;
<bullet> Install controls or reduce emissions for regional haze
pollutants that ODEQ determines, in its sole discretion, provide
equivalent emissions reductions to controls that would be identified as
cost effective for that source following the adjustment and review of a
four-factor analysis. ODEQ must establish a timeline for installation
of those controls that is the fastest practicable timeline for
installation of the identified controls and that is no later than July
31, 2026;
<bullet> Maintain controls that the source has already installed to
control regional haze pollutants or maintain reduced emissions of
regional haze pollutants that ODEQ determines, in its sole discretion,
have provided and will continue to provide equivalent emissions
reductions to controls that would be identified as cost effective for
that source following adjustment and review of a four-factor analysis;
or
<bullet> Replace an emissions unit with a new emissions unit that
meets the emission limits and requirements of the most recent
applicable standard in place at the time of the permitting of the new
emissions unit. ODEQ must establish a timeline for installation of the
new emissions unit that is the fastest practicable timeline for
installation of the new emissions unit and that is no later than July
31, 2031.
OAR 340-223-0120 Four Factor Analysis established the requirements
sources must follow in conducting the four-factor analyses consistent
with the Clean Air Act four statutory factors and provides ODEQ with
authority to request additional information or adjust the four-factor
analyses for consistency. Lastly, OAR 340-223-0130 Final Orders
Ordering Compliance with Round II of Regional Haze provides ODEQ
unilateral order authority to address those sources that do not enter
into a stipulated agreement and final order (SAFO) under OAR 340-223-
0110(2). OAR 340-223-0130 also outlines the contested case hearing
process for sources that challenge the unilateral orders issued by
ODEQ.
We have reviewed the revisions to the Division 223 Regional Haze
Rules and we are proposing to determine that they provide Oregon with
adequate authority to implement the regional haze program and are
consistent with CAA requirements and the EPA's Regional Haze Rule. ODEQ
submitted the revised Division 223 Regional Haze Rules for
incorporation by reference into the SIP at 40 CFR 52.1970(c) EPA
approved regulations and statutes and requested that the EPA remove
from the SIP the outdated source-specific BART provisions for the
Amalgamated Sugar Company and the PGE coal-fired power plant in
Boardman, which closed pursuant to the regional haze plan for the first
implementation period. We are proposing to approve this request and
incorporate by reference the submitted revised rules.
Stationary Source Screening
Pursuant to OAR 340-223-0100 Screening Methodology for Sources for
Round II of Regional Haze, ODEQ identified 32 facilities for analysis
using the four factors. As described in the previous paragraphs, the
PGE coal-fired power plant in Boardman ceased operation on October 15,
2020, and ODEQ removed the facility from the initial list of 32
facilities. The remaining operations onsite are known as Carty

[[Page 13639]]

Generating Station with an expected maximum Q/d of slightly over
1.00.\145\
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\145\ The Carty Generating Station is a 450 megawatt (MW),
combined-cycle natural gas-fueled electric generating power plant,
and includes a not-yet-constructed 50 MW solar PV electric power
generating unit (Carty Solar Farm) on 315 acres (0.49 sq. miles).
See <a href="https://www.oregon.gov/energy/facilities-safety/facilities/pages/cgs.aspx">https://www.oregon.gov/energy/facilities-safety/facilities/pages/cgs.aspx</a>.
---------------------------------------------------------------------------

Limits To Align PSELs to the Screening Threshold
As previously noted, ODEQ took a more inclusive approach of using
permitted emissions limits, PSELs, to screen facilities for source
selection. This yielded a much larger pool of facilities in the initial
screening rather than using projected actuals as suggested by the 2019
Guidance.\146\ OAR 340-223-0110(2)(b)(A) allows ODEQ to enter into an
agreement with a source to ``accept federally enforceable reductions of
combined plant site emission limits of round II regional haze
pollutants to bring the source's Q/d below 5.00.'' As noted in ODEQ's
April 29, 2021, SIP submission, ``if a facility's actual emissions were
below the screening threshold and potential emissions above the
screening threshold, ODEQ provided the source an opportunity to either
reduce pollutant-specific PSELs or take a limit on combined
NO<INF>X</INF>, SO<INF>2</INF>, and PM<INF>10</INF> PSELs such that Q/d
would be less than 5.00.'' \147\ If a source chose the option to reduce
PSELs, OAR 340-223-0110(2)(b)(A) exempted the source from further
control analysis. Importantly, OAR 340-223-0110(2)(b)(A) allows sources
to reduce PSELs as a compliance option at any point in the process from
initial screening through final agreements.\148\ To make the limits
Federally enforceable and permanent, ODEQ submitted the SAFOs and/or
permit conditions listed in table 7 for incorporation into the SIP in
40 CFR 52.1970(d) EPA approved state source-specific requirements.
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\146\ 2019 Guidance at 17.
\147\ April 29, 2022 Oregon SIP submission, Chapter 3.4. Four
Factor Analysis.
\148\ April 29, 2022 Oregon SIP submission, Chapter 6.6. Public
Comments and Responses, at page 147.
\149\ April 29, 2022 Oregon SIP submission, Chapter 3.7
Facility-specific findings and results.
\150\ ODEQ reviewed Kingsford Manufacturing Company which
originally screened into analysis with a Q/d = 8.39 based on actual
emissions as reported to the 2017 National Emissions Inventory (NEI)
because a 2017 PSEL was not available at that time. However, in a
letter dated May 22, 2020, ODEQ acknowledged a 2019 permit
modification that had already lowered PSELs for NO<INF>X</INF>,
SO<INF>2</INF>, and PM<INF>10</INF> to a Q/d = 4.02.\150\ As part of
the November 22, 2023 supplement, ODEQ submitted revised permit
conditions for the Kingsford Manufacturing Company that limit the
combined PSELs and unassigned emissions to 304 tons per year
yielding a Q/d = 4.98.
\151\ Alternatively, under Order 01-0038, the facility, up until
July 2026, could opt to commit to replace units EU1 and EU2 with new
technology by July 31, 2031, that would reduce Round 2 regional haze
pollutants. The technology would have to meet the emission limits
and requirements of the most recent New Source Performance Standard
in place at the time of the permittee submitting a permit
application for the project. PSELs for Round 2 regional haze
pollutants for the replacement shall be no more than 201 tons/year.
---------------------------------------------------------------------------

The EPA proposes to determine that Oregon's source selection was
reasonable and consistent with the requirements of 40 CFR
51.308(f)(2)(i). ODEQ included a thorough description of its source
selection methodology. ODEQ selected 23 sources for analysis under the
four factors. Considering these sources' PSELs and recent actual
emissions, ODEQ's source selection methodology targeted the sources
with the highest potential to impair visibility at mandatory Class 1
areas. Conversely, those sources ODEQ screened out have comparatively
limited potential impacts on visibility, specifically, all facilities
that accepted emission limits to screen out of analysis would have been
screened out of analysis using a Q/d <5 of actual emissions. Thus, the
EPA proposes to determine that Oregon's application of OAR 340-223-
0110(2)(b)(A) is a reasonable means of preventing future emissions
growth for facilities with relatively low Q/d values based on actual
current emissions.

Table 4--Facilities Screened in Using Q/d \149\
----------------------------------------------------------------------------------------------------------------
2017 Actual 2017 PSEL Q/
Facility Q/d d Outcome
----------------------------------------------------------------------------------------------------------------
PGE Boardman................................. 38.24 116.21 No four-factor analysis (FFA).
Facility shut down coal-fired
operations in 2020.
Ash Grove Cement Company..................... 18.54 38.47 No FFA. ODEQ determined 2013 consent
decree with the EPA represented
existing effective controls.
Klamath Energy LLC........................... 6.91 16.40 No FFA. ODEQ determined that newly
installed controls yield a Q/d
<5.00.
Kingsford Manufacturing Company \150\........ 8.38 NA No FFA--lowered PSEL to Q/d <5.00.
Cascades Tissue Group: A Division of Cascades 3.02 63.72 No FFA--lowered PSEL to Q/d <5.00.
Holding US Inc.
Timber Products Co. Limited Partnership...... 1.63 6.07 No FFA--lowered PSEL to Q/d <5.00.
PGE Beaver Plant/Port Westward I Plant....... 3.24 34.60 No FFA--lowered PSEL to Q/d <5.00.
Roseburg Forest Products--Riddle Plywood..... 2.10 5.29 No FFA--lowered PSEL to Q/d <5.00.
Roseburg Forest Products--Medford MDF........ 2.91 8.84 No FFA--lowered PSEL to Q/d <5.00.
Boise Cascade Wood Products, LLC--Medford.... 4.19 7.02 Conducted FFA--then lowered PSEL to Q/
d <5.00.
Gas Transmission Northwest LLC--Compressor 2.33 14.13 Conducted FFA--then lowered PSEL to Q/
Station 12. d <5.00.
JELD-WEN..................................... 2.13 6.30 Conducted FFA--then lowered PSEL to Q/
d <5.00.
Northwest Pipeline LLC--Baker Compressor 4.02 14.81 Conducted FFA--then lowered PSEL to Q/
Station \151\. d <5.00.
Pacific Wood Laminates, Inc.................. 8.29 12.50 Conducted FFA--ODEQ determined no
controls <$10K.
Swanson Group Mfg. LLC....................... 4.16 6.39 Conducted FFA--ODEQ determined no
controls <$10K.
Ochoco Lumber Company........................ 4.60 14.19 Conducted FFA--ODEQ determined no
controls <$10K.
Columbia Forest Products, Inc................ 4.10 7.75 Conducted FFA--ODEQ determined no
controls <$10K.
Collins Products, L.L.C...................... 4.78 10.82 Conducted FFA--ODEQ determined no
controls <$10K.
Woodgrain Millwork LLC--Particleboard........ 13.32 18.41 Conducted FFA--ODEQ determined no
controls <$10K

[[Page 13640]]

Gilchrist Forest Products.................... 8.42 15.74 Conducted FFA--source determined
controls cost effective. Modified
permit to incorporate controls.
Owens-Brockway Glass Container Inc........... 10.86 21.00 Conducted FFA--agreed order to impose
additional controls.
Boise Cascade Wood Products, LLC--Elgin 10.08 15.04 Conducted FFA--agreed order to impose
Complex. additional controls.
Georgia Pacific--Wauna Mill.................. 16.18 28.38 Conducted FFA--agreed order to impose
additional controls.
Cascade Pacific Pulp, LLC--Halsey Pulp Mill.. 8.86 23.69 Conducted FFA--agreed order to impose
additional controls.
Gas Transmission Northwest LLC--Compressor 2.34 19.68 Conducted FFA--agreed order to impose
Station 13. additional controls.
International Paper--Springfield............. 16.51 67.24 Conducted FFA--agreed order to impose
additional controls.
Georgia-Pacific--Toledo LLC.................. 7.83 20.33 Conducted FFA--agreed order to impose
additional controls.
Northwest Pipeline LLC--Oregon City 3.64 13.49 Conducted FFA--agreed order to impose
Compressor Station. additional controls.
EVRAZ Inc. NA................................ 3.57 11.92 Conducted FFA--agreed order to impose
additional controls.
Biomass One, L.P............................. 4.77 9.86 Conducted FFA--agreed order to impose
additional controls.
Roseburg Forest Products--Dillard............ 19.07 30.67 Conducted FFA--agreed order to impose
additional controls.
Willamette Falls Paper Company............... 3.79 26.46 Conducted FFA--agreed order to impose
additional controls.
----------------------------------------------------------------------------------------------------------------

Sources That Already Have Effective Emission Control Technology in
Place
In certain circumstances, states may properly determine that a
particular facility already has effective emission control technology
in place.\152\ A state that does not select a source or sources for
this reason should explain why the decision is consistent with the
requirement to make reasonable progress. ODEQ determined that 2
facilities of the originally screened 32 met this criterion, Klamath
Energy LLC and Ash Grove Cement.
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\152\ 2019 Guidance at 22; 2021 Clarifications Memo at 9.
---------------------------------------------------------------------------

In a May 28, 2020, letter from ODEQ to Klamath Energy, ODEQ
acknowledged plans by the facility to install ultra low-NO<INF>X</INF>
burners on the facility's combined cycle combustion turbines (emissions
units CT1 and CT2). These planned upgrades are in addition to Selective
Catalytic Reduction (SCR) control technology already in place at the
CT1 and CT2 units and other associated units, CT3 through CT6. ODEQ
estimated that the planned upgrades would reduce the facility combined
PM<INF>10</INF>, SO<INF>2</INF>, and NO<INF>X</INF> PSELs to 122 tons
per year, yielding a Q/d less than 5.00. Importantly, the 2020 permit
modification did not include revised PSELs, but relied on installation
of planned controls by January 1, 2022, as required under condition
3.a. of the permit modification. Therefore, as part of the November 22,
2023 supplement to the regional haze plan, ODEQ submitted relevant
portions of the December 8, 2020, permit modification detailing
installation and operation of the ultra low-NO<INF>X</INF> combustors,
as well as relevant conditions from the June 12 2017, permit to include
the existing pollution control devices for the remaining emissions
units for incorporation by reference into the SIP. In reviewing the
planned controls for these units, as well as the existing controls for
other units at the facility, we are proposing to determine the facility
has effective emission control technology in place, and those controls
and associated emissions limits are included in the SIP.
As discussed in Oregon's May 18, 2020, letter included in the
docket for this action, the Ash Grove Cement, Durkee plant recently
underwent a control analysis and ODEQ determined that no additional
controls required through the regional haze second implementation
period were likely to be effective or reasonable.\153\ To reach this
determination, ODEQ reviewed information the facility sent regarding
particulate matter emissions which are controlled by a recently
installed baghouse system in accordance with the 2018 Portland Cement
National Emission Standards for Hazardous Air Pollutants (NESHAP)
revisions, the facility's Air Contaminant Discharge Permit (ACDP) from
2017 (Permit No. 01-0029-CS-01), and the 2017 administrative amendment
to the permit (Permit No. 01-0029-TV-01).\154\ In addition, ODEQ
considered the enforcement actions that the EPA took on Portland Cement
companies in conjunction with the State of Oregon and the resulting
consent decrees to further control emissions.\155\ With respect to the
plant in Durkee, the consent decree required installation and
continuous operation of selective noncatalytic reduction (SNCR) at Kiln
1, a 30-day rolling average emission limit of 2 pounds NO<INF>X</INF>
per ton of clinker, and a 3-hour average emission limit of 0.4 pounds
SO<INF>2</INF> per ton of clinker. Based on the controls from the 2018
NESHAP and the consent decree requirements, ODEQ determined that the
facility has effective emission control technology in place. We are
proposing to concur with that determination for this planning period.
ODEQ submitted the October 16, 2020, Title V permit for Ash Grove
Cement for the incorporation of relevant permit conditions in the SIP
for the existing controls and emissions limits related to regional
haze.
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\153\ 100_haze-AshGroveCement-Durkee.pdf.
\154\ April 29, 2022 Oregon SIP submission, Chapter 3.7.2 Ash
Grove Cement Co, Durkee (01-0029).
\155\ 100a_ashgrove-cd.pdf included in the docket for this
action.

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[[Page 13641]]

Facilities With Additional Controls
Under OAR 340-223-0110(1) all sources subject to the requirements
of the regional haze second implementation period, as determined in OAR
340-223-0100 Screening Methodology for Sources for Round II of Regional
Haze, were required to submit a four-factor analysis consistent with
the provisions of OAR 340-223-0120 Four Factor Analysis. Specifically,
sources were required to conduct four-factor analyses for all ``round
II regional haze pollutants'' defined by Oregon as SO<INF>2</INF>,
NO<INF>X</INF>, and PM<INF>10</INF>. Under 340-223-0120, ODEQ may
adjust information in the four-factor analyses for consistency or
adjust the four-factor analyses based on other information ODEQ
determines to be accurate, adequate, and sufficient. ODEQ reviewed the
four-factor analyses from the facilities and adjusted for consistency
with basic factors such as interest rates, equipment lifetime, and
using potential to emit (PSEL) levels instead of actual emissions in
determining potential cost-effective controls.
The four-factor analyses submitted to ODEQ pursuant to 340-223-
0120, with the exception of Owens-Brockway and Gilchrist Forest
Products, indicated that additional NO<INF>X</INF>, PM<INF>10</INF>,
and SO<INF>2</INF> controls were either technologically infeasible or
not cost effective. Nevertheless, Oregon reviewed these analyses and
determined that in some cases controls may be feasible and cost
effective. Accordingly, in letters dated January 21, 2021, ODEQ
notified facilities based on the information provided in the four-
factor analyses submitted by the sources that additional controls may
be reasonable at the cost effective $10,000 per ton reduction
threshold. ODEQ provided preliminary determinations of the control
measures that may be reasonable based on rough cost control analyses.
Importantly, these preliminary determinations did not factor in site-
specific feasibility or other source-specific considerations.
Therefore, the January 21, 2021, letters invited the affected
facilities to discuss ODEQ's preliminary determination and provide
additional information as the basis for alternative compliance through
a SAFO between the parties under OAR 340-223-0110(2). These SAFOs and
permit conditions imposed the new controls, emission limits, and/or
emission monitoring at 13 facilities discussed below.
Boise Cascade Wood Products, LLC--Elgin Complex--Order 31-0006 and
Associated Permit Conditions \156\
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\156\ Permit conditions: 56. Monitoring Requirement,
56a.Emission Calculation, Table 6 (Emission Factors) for Boilers 1
and 2 for PM<INF>10</INF>, SO<INF>2</INF>, NO<INF>X</INF>, 59-61.
General Monitoring Requirements, 62-65. General Recordkeeping
Requirements, 66-70 Boiler NESHAP Recordkeeping Requirements, and
71-75 General Reporting Requirements.
---------------------------------------------------------------------------

<bullet> Establishing a PSEL for SO<INF>2</INF> effective July 31,
2022.
<bullet> Installation of a Continuous Emission Monitoring System
(CEMS) on Boiler 1 and Boiler 2 to measure NO<INF>X</INF> emissions by
September 31, 2022.
<bullet> Installation of combustion improvement project or projects
designed to achieve emissions reductions of NO<INF>X</INF> from Boiler
1 and Boiler 2 by 15% by July 31, 2023.
Biomass One, L.P.--Order 15-0159
<bullet> Installation of CEMS on the north and south boilers by
July 31, 2022.
<bullet> NO<INF>X</INF> optimization plan within 180 days after
installation of the NO<INF>X</INF> CEMS.
<bullet> If Permittee is able to finalize a new power purchase
agreement (PPA), Permittee shall notify ODEQ in writing within 14
calendar days. Or, if no new PPA is signed, Permittee shall cease
operation by January 1, 2027, and request cancellation of their Title V
operating permit.
<bullet> If a new PPA is signed, then no later than 180 days after
notifying ODEQ of the new PPA, the Permittee shall submit a complete
application for installation of NO<INF>X</INF> reduction technology
that includes SCR on the North Boiler and South Boiler or demonstrates
SCR is technically infeasible or presents other unacceptable energy or
non-air quality impact. If SCR is technically infeasible or presents
such other unacceptable impacts, the Permittee will propose the best
available, technically feasible, and achievable NO<INF>X</INF>
reduction option for ODEQ's review and approval. ODEQ will notify
Permittee and provide Permittee with a reasonable opportunity to
comment before approving a NO<INF>X</INF> reduction option in response
to Permittee's application.
EVRAZ Inc.--Order 26-1865
<bullet> By December 31, 2024, install low NO<INF>X</INF> burners
on the pre-heat portions of EU-10 Reheat Furnace with a designed
NO<INF>X</INF> emission factor of 170 pounds per million cubic feet of
natural gas.
<bullet> During 2025, the permittee shall conduct source testing to
verify the NO<INF>X</INF> emission factor for the EU-10 reheat furnace.
After consultation with the permittee, ODEQ will calculate the new
potential to emit (PTE) from EU-10 reheat furnace using the new
NO<INF>X</INF> emission factor and adjust the permittee's
NO<INF>X</INF> PSEL in its permit to account for the revised PTE,
either pursuant to OAR 340-218-0200(1)(a)(A), as applicable, or upon
permit renewal.
Georgia-Pacific--Toledo LLC--Order 21-0005
<bullet> By July 31, 2026, the permittee shall complete a
NO<INF>X</INF> reduction project that includes the installation of low
NO<INF>X</INF> burners, flue gas recirculation, and CEMS on the three
boilers, EU-11, EU-13, and EU-18 in order to achieve an emissions rate
no greater than 0.09 lb/MMBtu on a seven day rolling basis.
<bullet> Or, the permittee shall complete replacement of EU-11, EU-
13, and EU-18 with new technology no later than July 3l, 2031. PSELs
for the replacement shall be 889 tons per year of NO<INF>X</INF>, 437
tons per year of SO<INF>2</INF>, and 311 tons per year of
PM<INF>10</INF>, or the PSELs of the replaced units, whichever is
lower. Under this option, the permittee shall not operate EU-11, EU-13,
and EU-18 after July 31, 2031.
Georgia Pacific--Wauna Mill--Order No. 04-0004, Amendment No. 04-004-A1
<bullet> NO<INF>X</INF> PSEL reductions phased from 2022 to 2026.
<bullet> By December 31, 2024, the permittee shall replace the
existing Yankee burner with a low NO<INF>X</INF> burner achieving less
than or equal to 0.03 pounds per million British thermal unit (lb/
MMBtu).
<bullet> For Paper Machine 6: TAD1 Burner and TAD2 Burner, and
Paper Machine 7: TAD1 Burner and TAD 2 Burner, the permittee shall have
a NO<INF>X</INF> emissions rate no greater than 0.06 lb/MMBtu for each
emissions point and shall use this emission rate for calculating
compliance with PSELs.
<bullet> By July 31, 2026, the permittee shall install low
NO<INF>X</INF> burners, flue gas recirculation, and CEMS on the power
boiler to achieve an emissions rate no greater than 0.09 lb/MMBtu on a
seven day rolling basis.
International Paper Company--Springfield Mill--Order 208850 and
Associated Permit Conditions \157\
---------------------------------------------------------------------------

\157\ Permit conditions: 186-189: PSEL monitoring for
PM<INF>10</INF>, NO<INF>X</INF> and SO<INF>2</INF>, 192:
recordkeeping requirements, and 198: PSEL compliance reporting.
---------------------------------------------------------------------------

<bullet> Effective July 31, 2022, the permittee's combined assigned
PSELs for the power boiler, package boiler, lime kilns and recovery
furnace shall be 237 tons per year for SO<INF>2</INF>, 962 tons per
year for NO<INF>X</INF>, and 177 tons per year for PM<INF>10</INF>, as
a 12-month rolling average.

[[Page 13642]]

<bullet> On the effective date of the SAFO, the permittee agrees to
a fuel restriction to use natural gas for the power boiler and package
boiler, except that it may operate on ultra-low sulfur diesel for no
more than 48 hours per year and when needed for natural gas
curtailments.
<bullet> On the effective date of the SAFO, the permittee agrees to
a fuel restriction to use natural gas and black liquor solids for the
recovery furnace, except that it may operate on ultra-low sulfur diesel
for no more than 48 hours per year and when needed for natural gas
curtailments.
<bullet> On the effective date of the SAFO, the permittee agrees to
a fuel restriction to use natural gas, product turpentine, and product
methanol for the lime kilns, except that it may operate the lime kilns
on ultra-low sulfur diesel for no more than 48 hours per year and when
needed for natural gas curtailments.
<bullet> By December 31, 2022, the permittee shall install CEMS and
measure the emissions of NO<INF>X</INF> from the power boiler.
<bullet> On and after January 31, 2025, International Paper shall
meet the following emission limit: a 0.25 lb NO<INF>X</INF>/MMBtu on a
7-day rolling average from the power boiler.
<bullet> On and after December 31, 2025, the assigned PSEL for the
power boiler is: 179 tons per year for NO<INF>X</INF>, as a 12-month
rolling average.
In Oregon's November 22, 2023 supplement to the regional haze
SIP,\158\ ODEQ provided technical background information to demonstrate
that the newly imposed conditions under Order 208850 at International
Paper Company Springfield Mill for the second regional haze planning
period provide more stringent emissions control than the prior emission
limits and methods cited by the EPA in our determination that this
source was not subject-to-BART in the first regional haze planning
period.\159\
---------------------------------------------------------------------------

\158\ Page 4.
\159\ 75 FR 12651, March 8, 2011, at page 12660.
---------------------------------------------------------------------------

Owens-Brockway--Order 26-1876 and Associated Permit Conditions \160\
---------------------------------------------------------------------------

\160\ Permit conditions: 33. Monitor and Record: for
PM<INF>10</INF>, SO<INF>2</INF>, and NO<INF>X</INF>, 34. General
Testing Requirement, 35. EU4 Emission Factor Verification Testing
Requirements: for PM<INF>10</INF>, NO<INF>X</INF>, SO<INF>2</INF>,
36-38. General Monitoring and Recordkeeping Requirements, 39-42.
General Recordkeeping Requirements, 43-46. General Reporting
Requirements, and 47-48. Semi-annual and Annual Reports.
---------------------------------------------------------------------------

<bullet> Permanent shutdown of Furnace A.
<bullet> PSEL limit for combined PM<INF>10</INF> + NO<INF>X</INF> +
SO<INF>2</INF> = 274.95 tons per year which results in a Q/d = 4.99,
consistent with OAR 340-223-0110(2)(b)(A).
Willamette Falls Paper Company--Order 03-2145 and Associated Permit
Conditions \161\
---------------------------------------------------------------------------

\161\ Permit conditions: 40a-40g. Monitoring Requirement: for
PM<INF>10</INF>, NO<INF>X</INF>, SO<INF>2</INF>, 41. Visible
Emission Monitoring Procedure, 42. Source Testing and Emission
Factor Verification Procedure: for PM<INF>10</INF>, NO<INF>X</INF>,
SO<INF>2</INF>, 43-45. General Monitoring Requirements, 46-49.
General Recordkeeping Requirements, 50-53. General Reporting
Requirements, and 54-56. Semi-annual and Annual Reports.
---------------------------------------------------------------------------

<bullet> Effective August 1, 2022, the permittee's PSELs shall be
20 tons per year for PM<INF>10</INF>, 240 tons per year for
NO<INF>X</INF>, and 5 tons per year for SO<INF>2</INF>.
<bullet> On the effective date of the SAFO, the permittee agrees to
a restriction that the only fuel the permittee may combust in Boiler 1,
Boiler 2 and Boiler 3 is natural gas, except for ultra-low sulfur
diesel for no more than 48 hours per year.
Gas Transmission Northwest Compressor Station 13--OAH CASE NO. 2021-
ABC-4835 DEQ CASE NO. AQ/RH-HQ-2021-140 and Associated Permit
Conditions \162\
---------------------------------------------------------------------------

\162\ Permit conditions: 24-26. General Monitoring Requirements,
32-35. General Recordkeeping Requirements, 37-40. General Reporting
Requirements, and 41-44. Semi-Annual and Annual Reports.
---------------------------------------------------------------------------

<bullet> By July 31, 2026, install and maintain SCR and an
associated monitoring system on both Turbines 13C and 13D.
<bullet> Alternatively, by no later than July 31, 2031, replace
Turbines 13C and 13D with new technology that meets the most recent
permitting standards and requirements for new emission units (including
but not limited to New Source Performance Standards) in place at the
time of the respondent submitting a permit application for the project.
Gilchrist Forest Products--Permit 18-0005-TV-01, Addendum No. 1
<bullet> Installation of an electrostatic precipitator on boilers
B-1 and B-2.
<bullet> A PM<INF>10</INF> PSEL reduction from 172 tpy to 77 tpy.
Northwest Pipeline LLC--Oregon City Compressor Station--Order 03-2729,
Amendment 03-2729-A1
<bullet> Under the SAFO, the permittee agrees to replace two
reciprocating internal combustion engines to meet the emission limits
and requirements of the most recent New Source Performance Standard. No
later than July 1, 2026, ODEQ and the permittee will meet to discuss
what permitting needs are necessary for the replacement, with
replacement complete no later than July 31, 2031.
Cascade Pacific Pulp, LLC--Halsey Pulp Mill--Order 22-3501-A2
<bullet> By June 30, 2024, the permittee shall eliminate the use of
#6 fuel oil.
<bullet> No later than July 31, 2031, replace power boiler #2 with
a new emissions unit that will achieve a limit of 0.036 lbs
NO<INF>X</INF>/MMBtu as a 30-day rolling average.
<bullet> Upon replacement of power boiler #2, limit emissions from
power boiler #1 to no more than 27 tons of NO<INF>X</INF> per year.
Roseburg Forest Products, Dillard--Order 10-0025
<bullet> By July 31, 2022, the permittee shall install CEMS to
measure the emissions of NO<INF>X</INF> from Boiler 1, Boiler 2 and
Boiler 6.
<bullet> From January 31, 2023, until June 30, 2025, the permittee
shall meet the following emission limits: 0.30 lb NO<INF>X</INF>/MMBtu
on a 7-day rolling average at Boiler 1; 0.30 lb NO<INF>X</INF>/MMBtu on
a 7-day rolling average at Boiler 2; 0.28 lb NO<INF>X</INF>/MMBtu on a
7-day rolling average at Boiler 6; Or average of emissions from boiler
1, boiler 2, and boiler 6 of 0.28 lb NO<INF>X</INF>/MMBtu (7-day
rolling average).
<bullet> By January 31, 2024, the permittee shall notify ODEQ
whether the permittee will comply with the emission limits below using
boiler optimization or through installation of SNCR. If permittee
determines SNCR is necessary to meet emission limits, SNCR shall be
installed, permitted, and operational by June 30, 2025.
<bullet> On and after June 30, 2025, the permittee shall meet the
following emission limits: 0.27 lb NO<INF>X</INF>/MMBtu on a 7-day
rolling average at Boiler 1; 0.26 lb NO<INF>X</INF>/MMBtu on a 7-day
rolling average at Boiler 2; 0.26 lb NO<INF>X</INF>/MMBtu on a 7-day
rolling average at Boiler 6; or average of emissions from Boiler 1,
Boiler 2, and Boiler 6 of 0.25 lb NO<INF>X</INF>/MMBtu (7-day rolling
average).
The EPA notes that each of the controls and emission limits
discussed above limit emissions of one or more of the ``round II
regional haze pollutants.'' In most cases, Oregon determined that
NO<INF>X</INF> was the dominant visibility-impairing pollutant from the
sources and thus imposed additional NO<INF>X</INF> controls or
submitted the enforceable emission limitations for existing
NO<INF>X</INF> controls. For some emission units within the stationary
sources discussed in the previous paragraphs, Oregon did not adopt
additional pollutant-specific controls, primarily for PM<INF>10</INF>
and SO<INF>2</INF>. Based on a review of the four-factor analyses,
Oregon determined that these emission units either already employ
existing effective controls or, by virtue of design, have insignificant
emissions.

[[Page 13643]]

In particular, Oregon determined that PM<INF>10</INF> emissions for
most of the relevant emission units have been and continue to be
controlled by multiclones, electrostatic precipitators, baghouses, or
other feasible technology that consistently achieves >90% control
efficiency for PM<INF>10</INF>. As a general matter, the four-factor
analyses indicated that PM<INF>10</INF> controls have been in place for
many years to meet Federal NESHAP, NSPS, or Oregon SIP requirements and
that these controls must remain in place to meet these continuing
standards for the duration of the second planning period.\163\
Accordingly, Oregon determined that these existing effective controls
were not necessary for reasonable progress for the second planning
period.
---------------------------------------------------------------------------

\163\ See, e.g., 115_18-0013Collins4FA.pdf at 3-4;
104_haze_BoiseCasecade-ElginFFA.pdf at 2-14; 107_haze-BoiseCascade-
Medford-FFA.pdf; 110_haze-CascadePacificPulp-HalseyMill-FFA.pdf at
2-8, 3-5, 4-6-4-11, 3; 117_18-0014ColumbiaForestProducts4FA.pdf at
11.
---------------------------------------------------------------------------

In other cases, Oregon determined that the nature and mode of
operation of particular sources yielded insignificant emissions. For
example, at the Boise Cascade Wood Products, LLC's Elgin and Medford
Mills the sulfur content of wood derived fuel is low, and the majority
of the sulfur content is combined with the ash products of
combustion.\164\ Thus, Oregon either did not select these emission
units for four-factor analysis for a given pollutant or determined that
the existing emission limits for a given pollutant were not necessary
for reasonable progress. Therefore, Oregon focused primarily on
NO<INF>X</INF> and SO<INF>2</INF>, with PM<INF>10</INF> analysis and
limits when warranted. Accordingly, to the extent that Oregon did not
submit the enforceable emission limitations for PM<INF>10</INF> or
other pollutant controls for certain emission units within a given
source selected for four-factor analysis the EPA proposes to determine
that Oregon's selection of emission units to review under the four
factors is consistent with the Regional Haze Rule and that the existing
effective controls are not necessary for reasonable progress.
---------------------------------------------------------------------------

\164\ See 104_haze_BoiseCasecade-ElginFFA.pdf at 2-15; 107_haze-
BoiseCascade-Medford-FFA.pdf at 2-4.
---------------------------------------------------------------------------

Facilities for Which No Controls Were Cost-Effective
ODEQ reviewed the four-factor analyses from the facilities and
adjusted for consistency with basic factors such as using current prime
rate (3.25%), 30-year lifetime, and calculation of cost effective
controls using PSEL emissions limits rather than actual emissions.
After initial review, ODEQ ruled out control devices for which the cost
of control was greater than $10,000 per ton or provided an emissions
reduction (using emissions at PSEL) of less than 20 tons per year. In
letters sent August and September 2020, ODEQ notified 6 facilities with
the determination that the agency did not find any controls deemed cost
effective at the $10,000/ton threshold.\165\ These facilities were
Pacific Wood Laminates, Inc., Swanson Group Mfg. L.L.C., Ochoco Lumber
Company, Columbia Forest Products, Inc., Collins Products, L.L.C., and
Woodgrain Millwork L.L.C.--Particleboard. In order to ensure no future
impairment to visibility from these facilities, ODEQ submitted Title V
permits for these facilities to incorporate into the SIP permitting
conditions for these existing controls relevant to the regional haze
program. The EPA reviewed these four-factor analyses, and we propose to
find that ODEQ's determinations for these sources are reasonable and
consistent with 40 CFR 51.308(f)(2)(i) and (iii).
---------------------------------------------------------------------------

\165\ The facility-submitted four-factor analyses and ODEQ
response letters are included in the docket for this action.
---------------------------------------------------------------------------

The EPA's Proposed Approval Oregon's Long-Term Strategy for Stationary
Sources
The EPA reviewed ODEQ's four-factor analyses, determinations of
controls necessary for reasonable progress, and submitted SAFOs and
permit conditions. Based on this review, the EPA proposes to determine
that Oregon's long-term strategy meets the requirements of 40 CFR
51.308(f)(2)(i) through (iii). Oregon submitted numerous four-factor
analyses and demonstrated that its determination of controls necessary
for reasonable progress were an outgrowth of its consideration of the
four statutory factors. Notably, Oregon's $10,000 cost per ton
threshold is one of, if not the highest, cost thresholds established by
any state specifically for evaluating controls for the regional haze
program. Ultimately, Oregon imposed new, substantive controls at 13
facilities (covering over 36 emissions units) and established emissions
limits at an additional 10 facilities with low actual emissions to
ensure that future emissions do not rise above the screening threshold.
The EPA acknowledges that the final control measures imposed by the
SAFOs and permits described in the preceding paragraphs in some cases
differ from Oregon's preliminary control determinations contained in
ODEQ's January 21, 2021, letters. We reviewed the four-factor analyses
and Chapter 3.7 of Oregon's regional haze SIP, Facility-Specific
Findings and Results, which contain a brief overview of the site-
specific and feasibility concerns ODEQ considered in making final
determinations, along with additional supporting information contained
in the November 22, 2023, supplement.
Based on this review, the changes from preliminary to final control
determinations appear reasonable and consistent with the Regional Haze
Rule. Importantly, Oregon's iterative process to identify and adopt
technically feasible, cost-effective controls reinforces that the State
considered the four statutory factors to determine the controls
necessary for reasonable progress.
Considering ODEQ's conservative screening methodology to use
permitted emissions limits, the high $10,000 cost per ton reduction
threshold Oregon used in reviewing the four-factor analyses submitted
by the sources, the conservative methodology of evaluating controls
using permitted emissions limits, the number of new emissions controls
imposed specifically under the regional haze program, and the
significant emissions reductions achieved through the SAFOs described
in the previous paragraphs, we are proposing to determine that Oregon
satisfied the requirement to determine the emission reduction measures
that are necessary to make reasonable progress by considering the costs
of compliance, the time necessary for compliance, the energy and non-
air quality environmental impacts of compliance, and the remaining
useful life of any potentially affected anthropogenic source of
visibility impairment.
c. Additional Long-Term Strategy Requirements
The consultation requirements of 40 CFR 51.308(f)(2)(ii) provide
that states must consult with other states that are reasonably
anticipated to contribute to visibility impairment in a Class I area to
develop coordinated emission management strategies containing the
emission reductions measures that are necessary to make reasonable
progress. Section 51.308(f)(2)(ii)(A) and (B) require states to
consider the emission reduction measures identified by other states as
necessary for reasonable progress and to include agreed upon measures
in their SIPs, respectively. Section 51.308(f)(2)(ii)(C) speaks to what
happens if states cannot agree on

[[Page 13644]]

what measures are necessary to make reasonable progress.
Oregon participated in and provided documentation of the WRAP
intra- and inter-regional planning organization consultation processes
in the submission.\166\ Oregon also had direct consultations with
California, Idaho, Nevada, and Washington for sources where a Q/d
analysis showed potential impacts on Oregon Class I areas or where
Oregon sources may impact other states, as discussed in section IV.C of
this preamble. The Oregon SIP submissions contain the list of out-of-
state facilities potentially impacting Oregon Class I areas and a
summary of the four-factor analysis process and the potential controls
pursued by Idaho, Nevada, and Washington at the time of the
consultation.\167\ During the state-to-state consultation and WRAP
process, no other states identified measures for Oregon to consider.
Therefore, we are proposing to determine that the Oregon regional haze
plan satisfies 40 CFR 51.308(f)(2)(ii)(A) and (B). Oregon also
satisfies 40 CFR 51.308(f)(2)(ii)(C) by having participated in the
WRAP's consultation process and direct consultation with California,
Idaho, Nevada, and Washington. No disagreements were raised by other
states with respect to Oregon's planning efforts. We propose to
determine that Oregon has satisfied the consultation requirements of 40
CFR 51.308(f)(2)(ii).
---------------------------------------------------------------------------

\166\ April 29, 2022 Oregon SIP submission, Chapter 6.2.
Consultations with States.
\167\ April 29, 2022 Oregon SIP submission, Chapter 3.3 Impact
of facilities in other states on Oregon Class 1 areas.
---------------------------------------------------------------------------

The documentation requirement of 40 CFR 51.308(f)(2)(iii) provides
that states may meet their obligations to document the technical bases
on which they are relying to determine the emission reduction measures
that are necessary to make reasonable progress through a regional
planning organization, as long as the process has been ``approved by
all State participants.'' As explained above, Oregon chose to rely on
WRAP technical information, modeling, and analysis to support
development of its long-term strategy, as well as the State's own
analyses. The WRAP technical analyses on which Oregon relied are listed
in the State's SIP submissions and include source contribution
assessments, information on each of the four factors and visibility
modeling information for selected sources, and evaluations of emission
reduction strategies based on the anticipated control measures.\168\
Oregon also provided supplemental information to demonstrate the
technical bases and emission information on which it relied to
determine the emission reductions measures that are necessary to make
reasonable progress. Based on the documentation provided by the State,
we propose to find that Oregon has satisfied the requirements of 40 CFR
51.308(f)(2)(iii).
---------------------------------------------------------------------------

\168\ April 29, 2022, Oregon SIP submission, Chapter 5.1
Reasonable progress goals for Class I areas.
---------------------------------------------------------------------------

Section 51.308(f)(2)(iii) also 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. Oregon's SIP submission included 2017 NEI
emission data for regional haze forming pollutants. Based on Oregon's
consideration and analysis of emissions data in their SIP submissions,
the EPA proposes to find that Oregon has satisfied the emissions
information requirement in 40 CFR 51.308(f)(2)(iii).
We also propose to find that Oregon reasonably considered the five
additional factors in 40 CFR 51.308(f)(2)(iv) in developing its long-
term strategy. Pursuant to 40 CFR51.308(f)(2)(iv)(A), Oregon detailed
the existing and ongoing State and Federal emission control programs
that contribute to emission reductions through 2028. The Oregon
regional haze SIP highlights the State's aggressive programs for mobile
sources, including Oregon's adoption of California rules for medium-
and heavy-duty on-road vehicles, Low Emission Vehicle and ZEV standards
for passenger vehicles, and a state clean fuels program.\169\ Many of
these same measures, as well as other measures for the nonroad mobile
source category, also mitigate the impacts of construction activities
as required by 40 CFR 51.308(f)(2)(iv)(B).\170\
---------------------------------------------------------------------------

\169\ April 29, 2022 Oregon SIP submission, Chapter 4.5 Measures
to Mitigate Impacts of Construction Activities and Mobile Source
Strategies.
\170\ Ibid.
---------------------------------------------------------------------------

Pursuant to 40 CFR 51.308(f)(2)(iv)(C), source retirements and
replacement schedules are addressed in Chapter 4.4 Necessary Emission
Reduction Measures, On-going Air Pollution Control Programs and Source
Retirement/Replacement of Oregon's April 29, 2022, submission. The
primary source retirement considered in developing the 2028 emission
projections was permanent closure of the coal-fired power plant in
Boardman, as required under the regional haze plan for the first
implementation period.
In considering smoke management as required in 40 CFR
51.308(f)(2)(iv)(D), Oregon explained, in Chapter 4.6 Smoke Management
Practices and Programs and Area Source Strategies that it addresses
smoke management through its SIP-approved smoke management plan \171\
and open burning rules.\172\ Open burn rules limit all types of open
burning within the State and require that, where open burning is
allowed, it is conducted only after obtaining appropriate permits for
burning in specific locations on approved dates. Oregon also has
several existing measures that help improve visibility at Class I areas
including SIP-approved residential woodstove restrictions.\173\
---------------------------------------------------------------------------

\171\ 86 FR 27976, May 25, 2021.
\172\ 82 FR 47122, October 11, 2017.
\173\ OAR Division 262--Heat Smart Program for Residential
Woodstoves and Other Solid Fuel Heating Devices.
---------------------------------------------------------------------------

Oregon considered the anticipated net effect of projected changes
in emissions as required by 40 CFR 51.308(f)(2)(iv)(E) by discussing,
in Chapter 2.5 Source Apportionment of Visibility Impairment and
Weighted Emission Potential of its April 29, 2022, submission, the
photochemical modeling for the 2018-2028 period it conducted in
collaboration with the WRAP.
Because Oregon has reasonably considered each of the five
additional factors the EPA proposes to find that Oregon has satisfied
the requirements of 40 CFR 51.308(f)(2)(iv).

F. Reasonable Progress Goals

Section 51.308(f)(3) contains the requirements pertaining to
reasonable progress goals for each Class I area. Because Oregon is host
to Class I areas, it is subject to both 40 CFR 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 reasonable progress goals--one
each for the most impaired and clearest days--reflecting the visibility
conditions that will be achieved at the end of the implementation
period as a result of the emission limitations, compliance schedules
and other measures required under paragraph (f)(2) to be in states'
long-term strategies, as well as implementation of other Clean Air Act
requirements. The long-term strategies as reflected by the reasonable
progress goals 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

[[Page 13645]]

51.308(f)(3)(ii) applies in circumstances in which a Class I area's
reasonable progress goals for the most impaired days represents a
slower rate of visibility improvement than the uniform rate of progress
calculated under 40 CFR 51.308(f)(1)(vi). Under 40 CFR
51.308(f)(3)(ii)(A), if the state in which a Class I area is located
establishes a reasonable progress goal for the most impaired days that
provides for a slower rate of visibility improvement than the uniform
rate of progress, the state must demonstrate that there are no
additional emission reduction measures for anthropogenic sources or
groups of sources in the state that would be reasonable to include in
its long-term strategy. Section 51.308(f)(3)(ii)(B) requires that if a
state contains sources that are reasonably anticipated to contribute to
visibility impairment in a Class I area in another state, and the
reasonable progress goal for the most impaired days in that Class I
area is above the uniform rate of progress, the upwind state must
provide the same demonstration.
Chapters 2.1 Most Impaired Days and 2.2 Clearest Days of Oregon's
regional haze SIP summarize baseline visibility conditions (i.e.,
visibility conditions during the baseline period) for the most impaired
and clearest days, as well as information on natural visibility
conditions and the calculated URP in 2018 and 2028. Chapter 5.1
Reasonable progress goals for Class I Areas shows the 2028 RPGs for the
most impaired days and clearest days. The 2028 RPG projections are
based on WRAP modeling which represents regulations on the books as of
2020 plus stationary source controls recommended from ODEQ's review of
the four-factor analyses submittals. The modeled 2028 RPGs for the most
impaired days are presented in table 5 of this preamble, along with
adjusted and unadjusted 2028 URP glidepaths as calculated by the
EPA.\174\
---------------------------------------------------------------------------

\174\ Availability of Modeling Data and Associated Technical
Support Document for the EPA's Updated 2028 Visibility Air Quality
Modeling, September 2019.

Table 5--Reasonable Progress Goals for the Most Impaired Days
----------------------------------------------------------------------------------------------------------------
Unadjusted EPA 2028
Baseline Current WRAP glidepath default
Monitor ID Class I area 2000-2004 conditions 2028 20% most adjusted
(dv) 2014-2018 RPGs impaired glidepath
(dv) (dv) days (dv) (dv)
----------------------------------------------------------------------------------------------------------------
MOHO................ Mt. Hood Wilderness Area...... 12.10 9.27 8.50 9.90 10.71
THSI................ Mt. Jefferson, Mt. Washington, 12.80 11.28 10.86 10.60 11.62
and Three Sisters Wilderness
Areas.
CRLA................ Crater Lake National Park; 9.36 7.98 7.72 7.70 8.85
Diamond Peak, Mountain Lakes,
and Gearhart Mountain
Wilderness Areas.
KALM................ Kalmiopsis Wilderness Area.... 13.34 11.97 11.63 11.13 11.87
STAR................ Strawberry Mountain and Eagle 14.53 11.19 10.47 11.35 12.69
Cap Wilderness Areas.
HECA................ Hells Canyon Wilderness Area.. 16.51 12.33 11.66 12.53 13.93
----------------------------------------------------------------------------------------------------------------

The 2017 Regional Haze Rule included a provision that allows states
to propose an adjustment to the glidepath to account for impacts from
anthropogenic sources outside the U.S. if the adjustment has been
developed through scientifically valid data and methods. The EPA's
visibility guidance states ``to calculate the proposed adjustment(s),
the State must add the estimated impact(s) to the natural visibility
condition and compare the baseline visibility condition for the most
impaired days to the resulting sum.'' In 2019, the EPA conducted
modeling to assist states in the development of Regional Haze SIPs for
the second implementation period. In particular, the modeling provided
the EPA's first comprehensive estimate of international anthropogenic
emissions contributions to visibility impairment at Class I areas.\175\
ODEQ chose not to adjust the glidepath to account for impacts from
anthropogenic sources outside the U.S.
---------------------------------------------------------------------------

\175\ Availability of Modeling Data and Associated Technical
Support Document for the EPA's Updated 2028 Visibility Air Quality
Modeling, September 2019.
---------------------------------------------------------------------------

As noted in Chapter 2.3 Emissions Inventory Analysis of Oregon's
regional haze SIP submission, the 2017 SO<INF>2</INF> inventory is
dominated by PGE Boardman's coal-fired power plant in Morrow County.
With the closing of the plant in October 2020, statewide SO<INF>2</INF>
emissions declined by 62%. ODEQ further concludes that at some
monitors, ammonium sulfate is a large contributor to regional haze
formation, but that contribution seems to be dominated by international
anthropogenic sources and is projected to decrease by 77% as new
standards for international marine shipping fuels take effect in
2020.\176\ Therefore, even though Oregon declined to adjust the
glidepath for international anthropogenic sources, such as marine
shipping, we believe this is information relevant to our review. In
particular, all IMPROVE stations for Class I areas in Oregon have
modeled 2028 RPGs below the 2028 URP glidepath as adjusted for
international anthropogenic contribution for the most impaired days.
For the most impaired days, the 2028 RPGs also represent an improvement
relative to both baseline visibility conditions and current visibility
conditions. Similarly, for the clearest days, the 2028 RPGs also
represent an improvement relative to both baseline visibility
conditions and current visibility conditions, as shown in table 6 of
this preamble.
---------------------------------------------------------------------------

\176\ April 29, 2022 Oregon SIP submission, Chapter 2.1 Most
Impaired Days.

Table 6--Reasonable Progress Goals for the Clearest Days
------------------------------------------------------------------------
Current
Baseline conditions WRAP 2028
Monitor ID Class I area 2000-2004 2014-2018 RPGs (dv)
(dv) (dv)
------------------------------------------------------------------------
MOHO....... Mt. Hood Wilderness 2.17 1.39 1.29
Area.

[[Page 13646]]

THSI....... Mt. Jefferson, Mt. 3.04 2.61 2.53
Washington, and
Three Sisters
Wilderness Areas.
CRLA....... Crater Lake National 1.69 1.05 0.98
Park; Diamond Peak,
Mountain Lakes, and
Gearhart Mountain
Wilderness Areas.
KALM....... Kalmiopsis 6.27 5.90 5.84
Wilderness Area.
STAR....... Strawberry Mountain 2.17 1.39 1.29
and Eagle Cap
Wilderness Areas.
HECA....... Hells Canyon 5.52 4.00 3.79
Wilderness Area.
------------------------------------------------------------------------

As noted in the RHR at 40 CFR 51.308(f)(3)(iii), the reasonable
progress goals are not directly enforceable, but will be considered by
the Administrator in evaluating the adequacy of the measures in the
implementation plan in providing for reasonable progress towards
achieving natural visibility conditions at specific Class I areas.
Regardless of whether we use an adjusted or unadjusted URP glidepath to
evaluate Oregon's 2028 RPGs for the most impaired days, the regulatory
purpose of the RPGs has been fulfilled because visibility conditions
for all IMPROVE stations have improved since the baseline period.
That said, because Oregon did not adjust the glidepath and because
the 2028 RPGs for several Class I areas are above the unadjusted
glidepath, the demonstration requirement under 40 CFR
51.308(f)(3)(ii)(A) is triggered. Oregon addressed this obligation in
Chapter 5.2 Glidepath policy choice stating, ``DEQ's policy decision to
represent URP as an unadjusted glidepath has some effect on whether
2028 visibility projections fall slightly below or slightly above the
glidepath (primarily at the central and southern Oregon IMPROVE sites),
but DEQ did not base regulatory stationary source control decisions on
the URP. DEQ based control decisions on the factors described in
section 3 of this plan, including analyses based on the four statutory
factors. As discussed in section III.D. of this preamble, visibility
projections below the glidepath do not provide `safe harbor' for
sources.
The EPA acknowledges Oregon's position. The IMPROVE monitoring
stations in the Cascades (THSI and CRLA) and Kalmiopsis (KALM) that are
projected to have 2028 RPGs at or above the unadjusted glidepath are
the same IMPROVE monitoring stations that Oregon demonstrated are
highly impacted by international marine shipping as described in
section IV.E.a. of this preamble. These emissions are projected to
decrease by 77% due to new standards for international marine shipping
fuels which became effective in 2020.\177\ Also as described in section
IV.E.a. of this preamble, statewide NO<INF>X</INF> emissions are
primarily from mobile sources, at about 80% of the inventory. The
Oregon r

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