# Approval and Promulgation of Air Quality Implementation Plans; New York; Regional Haze State Implementation Plan for the Second Implementation Period

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URL: https://www.frixlaw.com/law-library/documents/fr%3A2024-06105

## Record

- **Collection:** Federal Register
- **Document type:** Proposed Rule
- **Published:** March 22, 2024
- **Citation:** 89 FR 20384

## Text

ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R02-OAR-2020-0455; FRL-11807-01-R2]
Approval and Promulgation of Air Quality Implementation Plans; New York; Regional Haze State Implementation Plan for the Second Implementation Period

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

The Environmental Protection Agency (EPA) is proposing to approve the regional haze state implementation plan (SIP) submitted by the State of New York through the Department of Environmental Conservation (NYSDEC or New York) on May 12, 2020, as satisfying applicable requirements under the Clean Air Act (CAA) and the EPA's Regional Haze Rule for the program's second implementation period. New York's SIP submission addresses the requirement that states must periodically revise their long-term strategies for making reasonable progress towards the national goal of preventing any future, and remedying any existing, anthropogenic impairment of visibility in mandatory Class I Federal areas, including regional haze. The SIP submission also addresses other applicable requirements for the second implementation period of the regional haze program. The EPA is taking this action pursuant to sections 110 and 169A of the Clean Air Act.

DATES:

Written comments must be received on or before April 22, 2024.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-R02-OAR-2020-0455 at
https://www.regulations.gov.
Although listed in the index, some information is not publicly available,
e.g.,
Controlled Unclassified Information (CUI) (formally referred to as Confidential Business Information (CBI)) or other information whose disclosure is restricted by statute. Certain other material, such as

copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are available electronically through
https://www.regulations.gov.
Follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from
Regulations.gov
. The EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be CUI or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission (
i.e.,
on the web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CUI or multimedia submissions, and general guidance on making effective comments, please visit
https://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT:

Robert Rutherford, U.S. Environmental Protection Agency, Air Programs Branch, Region II, 290 Broadway, New York, New York 10007-1866, at (212) 637-3712 or by email at
Rutherford.Robert@epa.gov.

SUPPLEMENTARY INFORMATION:

I. What action is the EPA proposing?

II. Background and Requirements for Regional Haze Plans

A. Regional Haze Background

B. Roles of Agencies in Addressing Regional Haze

III. Requirements for Regional Haze Plans for the Second Implementation Period

A. Identification of Class I Areas

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

C. Long-Term Strategy for Regional Haze

D. Reasonable Progress Goals

E. Monitoring Strategy and Other Implementation Plan Requirements

F. Requirements for Periodic Reports Describing Progress Towards the Reasonable Progress Goals

G. Requirements for State and Federal Land Manager Coordination

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

A. Background on New York's First Implementation Period SIP Submission

B. New York's 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. New York's Response to the Six MANE-VU Asks

b. The EPA's Evaluation of New York's Response to the Six MANE-VU Asks and Compliance With 40 CFR 51.308(f)(2)(i)

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. Environmental Justice Considerations

VI. The EPA's Proposed Action

VII. Statutory and Executive Order Reviews

I. What action is the EPA proposing?

On May 12, 2020, NYSDEC submitted a revision to its SIP to address regional haze for the second implementation period (“NY RH 2nd Implementation Period SIP submission”). NYSDEC supplemented its SIP submission on February 16, 2022. NYSDEC made this SIP submission to satisfy the requirements of the CAA's regional haze program pursuant to CAA sections 169A and 169B and 40 CFR 51.308. The EPA is proposing to find that the NY RH 2nd Implementation Period SIP submission meets the applicable statutory and regulatory requirements and thus proposes to approve New York's SIP revision submission.

II. Background and Requirements for Regional Haze Plans

A. Regional Haze Background

In the 1977 CAA Amendments, Congress created a program for protecting visibility in the nation's mandatory Class I Federal areas, which include certain national parks and wilderness areas.
1

CAA 169A. The CAA establishes as a national goal the “prevention of any future, and the remedying of any existing, impairment of visibility in mandatory class I Federal areas which impairment results from manmade air pollution.” CAA 169A(a)(1). The CAA further directs the EPA to promulgate regulations to assure reasonable progress toward meeting this national goal. CAA 169A(a)(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. (45 FR 80084, December 2, 1980). 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 CAA to further address visibility impairment; specifically, impairment from regional haze. CAA 169B. The EPA promulgated the Regional Haze Rule (RHR), codified at 40 CFR 51.308,
2

on July 1, 1999. (64 FR 35714, July 1, 1999). These regional haze regulations are a central component of the EPA's comprehensive visibility protection program for Class I areas.

1
Areas statutorily designated as mandatory Class I Federal areas consist of national parks exceeding 6,000 acres, wilderness areas and national memorial parks exceeding 5,000 acres, and all international parks that were in existence on August 7, 1977. CAA 162(a). There are 156 mandatory Class I areas. The list of areas to which the requirements of the visibility protection program apply is in 40 CFR part 81, subpart D.

2
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.

Regional haze is visibility impairment that is produced by a multitude of anthropogenic sources and activities which are located across a broad geographic area and that emit pollutants that impair visibility. Visibility impairing pollutants include: fine and coarse particulate matter (PM) (
e.g.,
sulfates, nitrates, organic carbon, elemental carbon, and soil dust), and their precursors (
e.g.,
sulfur dioxide (SO
2
); nitrogen oxides (NO
X
); and, in some cases, volatile organic compounds (VOC) and ammonia (NH
3
)). Fine particle precursors react in the atmosphere to form fine particulate matter (PM
2.5
), which impairs visibility by scattering and absorbing light. Visibility impairment reduces the perception of clarity and color, as well as visible distance.
3

3
There are several ways to measure the amount of visibility impairment,
i.e.,
haze. One such measurement is the deciview, which is the principal metric used by the RHR. Under many circumstances, a change in one deciview will be perceived by the human eye to be the same on both clear and hazy days. The deciview is unitless. It is proportional to the logarithm of the atmospheric extinction of light, which is the perceived dimming of light due to its being scattered and absorbed as it passes through the atmosphere. Atmospheric light extinction (b
ext
) is a metric used to for expressing visibility and is measured in inverse megameters (Mm-1). T

he 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,
https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period.
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.

To address regional haze visibility impairment, the 1999 RHR established an iterative planning process that requires both states in which Class I areas are located and states “the emissions from which may reasonably be anticipated to cause or contribute to any impairment of visibility” in a Class I area to periodically submit SIP revisions to address such impairment. CAA 169A(b)(2);
4

see
also 40 CFR 51.308(b), (f) (establishing submission dates for iterative regional haze SIP revisions); (64 FR 35768, July 1, 1999). Under the CAA, each SIP submission must contain “a long-term (ten to fifteen years) strategy for making reasonable progress toward meeting the national goal,” CAA 169A(b)(2)(B); 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). CAA 169A(b)(2)(A); 40 CFR 51.308(d), (e). States' first regional haze SIPs were due by December 17, 2007, 40 CFR 51.308(b), with subsequent SIP submissions containing updated long-term strategies originally due July 31, 2018, and every ten years thereafter. (64 FR 35768, July 1, 1999). The EPA established in the 1999 RHR 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.
5

(64 FR 35721, July 1, 1999).

4
The RHR expresses the statutory requirement for states to submit plans addressing out-of-state class I areas by providing that states must address visibility impairment “in each mandatory Class I Federal area located outside the State that may be affected by emissions from within the State.” 40 CFR 51.308(d), (f).

5
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).

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 (RPGs) 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 RPGs 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 RPGs 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. CAA 169A(g)(1); 40 CFR 51.308(d)(1).

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 (URP) 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.
6

40 CFR 51.308(d)(1)(i)(B), (d)(2). The 1999 RHR 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.” 40 CFR 51.308(d)(3). 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 RPGs. 40 CFR 51.308(d)(3)(i), (ii). Section 51.308(d) also contains seven additional factors states must consider in formulating their long-term strategies, 40 CFR 51.308(d)(3)(v), as well as provisions governing monitoring and other implementation plan requirements. 40 CFR 51.308(d)(4). Finally, the 1999 RHR 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,
see
40 CFR 51.308(g), (h)—and to consult with the Federal Land Manager(s)
7

(FLMs) responsible for each Class I area according to the requirements in CAA 169A(d) and 40 CFR 51.308(i).

6
EPA established the URP framework in the 1999 RHR 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 URP analysis is 2004 and the endpoint was calculated based on the amount of visibility improvement that was anticipated to result from implementation of existing CAA programs over the period from the mid-1990s to approximately 2005. Assuming this rate of progress would continue into the future, EPA determined that natural visibility conditions would be reached in 60 years, or 2064 (60 years from the baseline starting point of 2004). However, EPA did not establish 2064 as the year by which the national goal
must
be reached. (64 FR 35731-32, July 1, 1999). That is, the URP 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 URP.” (82 FR 3078, 3084, January 10, 2017).

7
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-Campobellow International Park, the Chairman of the Roosevelt-Campobellow International Park Commission.” 40 CFR 51.301.

On January 10, 2017, the EPA promulgated revisions to the RHR, (82 FR 3078, January 10, 2017), that apply for the second and subsequent implementation periods. The 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 RHR Revisions) are codified at 40 CFR 51.308(f). Among other changes, the 2017 RHR 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 RPGs 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 FLM consultation.

The specific requirements applicable to second implementation period regional haze SIP submissions are addressed in detail below.

The EPA provided guidance to the states for their second implementation period SIP submissions in the preamble to the 2017 RHR 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”).
8

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”).
9

Additionally, the EPA further clarified the recommended procedures for processing ambient visibility data and optionally adjusting the URP 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”),
10

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”).
11

8
Guidance on Regional Haze State Implementation Plans for the Second Implementation Period.
https://www.epa.gov/visibility/guidance-regional-haze-state-implementation-plans-second-implementation-period.
The EPA Office of Air Quality Planning and Standards, Research Triangle Park (August 20, 2019).

9
Clarifications Regarding Regional Haze State Implementation Plans for the Second Implementation Period.
https://www.epa.gov/system/files/documents/2021-07/clarifications-regarding-regional-haze-state-implementation-plans-for-the-second-implementation-period.pdf.
The EPA Office of Air Quality Planning and Standards, Research Triangle Park (July 8, 2021).

10
Technical Guidance on Tracking Visibility Progress for the Second Implementation Period of the Regional Haze Program.
https://www.epa.gov/visibility/technical-guidance-tracking-visibility-progress-second-implementation-period-regional.
The EPA Office of Air Quality Planning and Standards, Research Triangle Park. (December 20, 2018).

11
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.
https://www.epa.gov/visibility/memo-and-technical-addendum-ambient-data-usage-and-completeness-regional-haze-program.
The EPA Office of Air Quality Planning and Standards, Research Triangle Park (June 3, 2020).

As previously explained in the 2021 Clarifications Memo, EPA intends 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 Agency 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 CAA programs, the Agency 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. See 2021 Clarifications Memo. This is consistent with Congress's determination that a visibility protection program is needed in addition to the CAA'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.
12

12

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”).

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 (RPOs),
13

which include representation from state and Tribal governments, the EPA, and FLMs, were developed in the lead-up to the first implementation period to address regional haze. RPOs evaluate technical information to better understand how emissions from State and Tribal land impact Class I areas across the country, pursue the development of regional strategies to reduce emissions of particulate matter and other pollutants leading to regional haze, and help states meet the consultation requirements of the RHR.

13
RPOs are sometimes also referred to as “multi-jurisdictional organizations,” or MJOs. For the purposes of this notice, the terms RPO and MJO are synonymous.

The Mid-Atlantic/Northeast Visibility Union (MANE-VU), one of the five RPOs described above, is a collaborative effort of state governments, Tribal governments, and various Federal agencies established to initiate and coordinate activities associated with the management of regional haze, visibility, and other air quality issues in the Mid-Atlantic and Northeast corridor of the United States. Member states and Tribal governments (listed alphabetically) include: Connecticut, Delaware, the District of Columbia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Penobscot Indian Nation, Rhode Island, St. Regis Mohawk Tribe, and Vermont. The Federal partner members of MANE-VU are EPA, U.S. National Parks Service (NPS), U.S. Fish and Wildlife Service (FWS), and U.S. Forest Service (USFS).

III. Requirements for Regional Haze Plans for the Second Implementation Period

Under the CAA and EPA's regulations, all 50 states, the District of Columbia, and the U.S. Virgin Islands are required to submit regional haze SIPs satisfying the applicable requirements for the second implementation period of the regional haze program by July 31, 2021. Each state's SIP must contain a long-term strategy for making reasonable progress toward meeting the national goal of remedying any existing and preventing any future anthropogenic visibility impairment in Class I areas. CAA 169A(b)(2)(B). To this end, 40 CFR 51.308(f) lays out the process by which states determine what constitutes their long-term strategies, with the order of the requirements in 40 CFR 51.308(f)(1) through (f)(3) generally mirroring the order of the steps in the reasonable progress analysis
14

and (f)(4) through (6) containing additional, related requirements. Broadly speaking, a state first must identify the Class I areas within the state and determine the Class I areas outside the state in which visibility may be affected by emissions from the state. These are the Class I areas that must be addressed in the

state's long-term strategy.
See
40 CFR 51.308(f), (f)(2). For each Class I area within its borders, a state must then calculate the baseline, current, and natural visibility conditions for that area, as well as the visibility improvement made to date and the URP.
See
40 CFR 51.308(f)(1). 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. Reasonable progress is determined by 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.
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 using the four statutory factors. Those measures are then incorporated into the state's long-term strategy. After a state has developed its long-term strategy, it then establishes RPGs for each Class I area within its borders by modeling the visibility impacts of all reasonable progress controls at the end of the second implementation period,
i.e.,
in 2028, as well as the impacts of other requirements of the CAA. The RPGs include reasonable progress controls not only for sources in the state in which the Class I area is located, but also for sources in other states that contribute to visibility impairment in that area. The RPGs are then compared to the baseline visibility conditions and the URP to ensure that progress is being made towards the statutory goal of preventing any future and remedying any existing anthropogenic visibility impairment in Class I areas. 40 CFR 51.308(f)(2) through (3).

14
EPA explained in the 2017 RHR Revisions that we were adopting new regulatory language in 40 CFR 51.308(f) that, unlike the structure in § 51.308(d), “tracked the actual planning sequence.” (82 FR 3091, January 10, 2017).

In addition to satisfying the requirements at 40 CFR 51.308(f) related to reasonable progress, the SIP submissions due by July 31, 2021, 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 RPGs, 40 CFR 51.308(f)(5), as well as requirements for FLM consultation that apply to all visibility protection SIPs and SIP revisions. 40 CFR 51.308(i).

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 CAA and EPA's regulations.
See
CAA 169A(b)(2); CAA 110(a). Upon EPA approval, a SIP is enforceable by the Agency and the public under the CAA. If 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 the EPA disapproves a state's SIP, the Agency must promulgate a Federal implementation plan (FIP) that satisfies the applicable requirements. CAA 110(c)(1).

A. Identification of Class I Areas

The SIP revision submission due by July 31, 2021, “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.” 40 CFR 51.308(f);
see
also 40 CFR 51.308(f)(2).
15

Thus, 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 RHR, the EPA determined that all states contribute to visibility impairment in at least one Class I area, (64 FR 35720-22, July 1, 1999) 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.”
Id.
at 35721.

15
The RHR uses the phrase “that may be affected by emissions from the State” to implement CAA 169A(b)(2)'s requirement that a state “the emissions from which may reasonably be anticipated to cause or contribute to any impairment of visibility” submit a SIP.

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 RHR does not require this evaluation to be conducted in any particular manner, 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, 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 RHR contains requirements in 40 CFR 51.308(f)(1) related to tracking visibility improvement over time. The requirements of this subsection apply only to states having Class I areas within their borders; the required calculations must be made for each such Class I area. EPA's 2018 Visibility Tracking Guidance
16

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 URP to account for the impacts of international anthropogenic emissions and prescribed fires.
See
82 FR 3103-0 (Jan. 10, 2017).

16
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
https://www3.epa.gov/ttnamti1/files/ambient/visible/tracking.pdf.

The RHR 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 RHR 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).
17

40 CFR 51.301. 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). 40 CFR 51.308(f)(1)(i), (iii). States must also calculate natural visibility conditions for the clearest and most impaired days,
18

by estimating the

conditions that would exist on those two sets of days absent anthropogenic visibility impairment. 40 CFR 51.308(f)(1)(ii). 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.

17
This notice also refers to the 20% clearest and 20% most anthropogenically impaired days as the “clearest” and “most impaired” or “most anthropogenically impaired” days, respectively.

18
The RHR 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 states “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 RHR Revisions but did not get corrected in the final rule language. This is supported by the preamble text at 82 FR 3098: “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.”

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 URP—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 URP 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.
19

Additionally, in the 2017 RHR Revisions, the EPA provided states the option of proposing to adjust the endpoint of the URP to account for impacts of anthropogenic sources outside the United States 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. 82 FR 3107 footnote 116.

19
Being on or below the URP is not a “safe harbor”;
i.e.,
achieving the URP 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 3093 (Jan. 10, 2017).

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 URP. 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).” 40 CFR 51.308(f)(2). The amount of progress that is “reasonable progress” is determined by applying the four statutory factors in CAA 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.
20

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.
See
40 CFR 51.308(f)(2)(i). 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. See 2019 Guidance at 43; 2021 Clarifications Memo at 8-10. 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. 40 CFR 51.308(f)(2).

20
Per CAA section 169A(g)(1), in determining reasonable progress states must take into consideration “the costs of compliance, the time necessary for compliance, and the energy and non-air quality environmental impacts of compliance, and the remaining useful life of any existing source subject to such requirements.” 42 U.S.C. 7491(g)(1).

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, the RHR requires states to 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. 40 CFR 51.308(f)(2)(i). A threshold question at this step is which visibility impairing pollutants will be analyzed. As EPA previously explained, consistent with the first implementation period, EPA generally expects that each state will analyze at least SO
2
and NO
X
in selecting sources and determining control measures. See 2019 Guidance at 12, 2021 Clarifications Memo at 4. A state that chooses not to consider at least these two pollutants should demonstrate why such consideration would be unreasonable. 2021 Clarifications Memo at 4.

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.” 2019 Guidance at 9. 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.” 2021 Clarifications Memo at 3.

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. 2021 Clarifications Memo at 4.
21

21
Similarly, in responding to comments on the 2017 RHR 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, May 4, 2016) at 87-88.

Thus, while states have discretion to choose any source selection methodology that is reasonable, whatever choices they make should be reasonably explained and result in a set of sources which capture a meaningful portion of the state's total contribution to visibility impairment. 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.
22

This is accomplished by considering the four factors—“the costs of compliance, the time necessary for compliance, and the energy and non-air quality environmental impacts of compliance, and the remaining useful life of any existing source subject to such requirements.” CAA 169A(g)(1). The EPA has explained that the four-factor analysis is an assessment of potential emission reduction measures (
i.e.,
control options) for sources; “use of the terms `compliance' and `subject to such requirements' in section 169A(g)(1) strongly indicates that Congress intended the relevant determination to be the requirements with which sources would have to comply in order to satisfy the CAA's reasonable progress mandate.” (82 FR 3091, Jan. 10, 2017). Thus, for each source it has selected for four-factor analysis,
23

a state must consider a “meaningful set” of technically feasible control options for reducing emissions of visibility impairing pollutants.
Id.
at 3088. 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.” 2019 Guidance at 29.

22
The CAA provides that, “[i]n determining reasonable progress there shall be taken into consideration” the four statutory factors. CAA 169A(g)(1). However, in addition to four-factor analyses for selected sources, groups of sources, or source categories, a state may also consider additional emission reduction measures for inclusion in its long-term strategy,
e.g.,
from other newly adopted, on-the-books, or on-the-way rules and measures for sources not selected for four-factor analysis for the second planning period.

23
“Each source” or “particular source” is used here as shorthand. While a source-specific analysis is one way of applying the four factors, neither the statute nor the RHR requires states to evaluate individual sources. Rather, states have “the flexibility to conduct four-factor analyses for specific sources, groups of sources or even entire source categories, depending on state policy preferences and the specific circumstances of each state.” (82 FR 3088, Jan. 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.

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.” 2021 Clarifications Memo at 7. In addition to add-on controls and other retrofits (
i.e.,
new emission reduction measures for sources), 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. 2021 Clarifications Memo at 7. 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.” See 2021 Clarifications Memo at 5, 10.

After identifying a reasonable set of potential control options for the sources it has selected, a state then collects 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 CAA and RHR to reasonably consider visibility benefits as an optional fifth factor alongside the four statutory factors.
24

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. See 2019 Guidance at 30-36. 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. 2021 Clarifications Memo at 12-13, 14-15. Specifically, EPA explained that while visibility impacts can reasonably be considered when comparing and choosing between multiple reasonable control options, visibility should not be used to reject controls that are reasonable given the four statutory factors. 2021 Clarifications Memo at 13. Ultimately, while states have discretion to reasonably weigh the factors and to determine what level of control is needed, 40 CFR 51.308(f)(2)(i) provides that a state “must include in its implementation plan a description of . . . how the four factors were taken into consideration in selecting the measure for inclusion in its long-term strategy.”

24

See, e.g.,
Responses to Comments on Protection of Visibility: Amendments to Requirements for State Plans; Proposed Rule (81 FR 26942, May 4, 2016), Docket Number EPA-HQ-OAR-2015-0531, U.S. Environmental Protection Agency at 186; 2019 Guidance at 36-37.

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.
25

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.
See
CAA 169A(a)(1). 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. 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. See 2021 Clarifications Memo at 8-10. 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.

25
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 EPA for inclusion in their SIPs but are not required to do so.
See, e.g.,
82 FR 3108-09, Jan. 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).

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.
26

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.

26

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
Nat'l Parks Conservation Ass'n
v.
EPA,
803 F.3d 151, 165 (3d Cir. 2015);
Alaska Dep't of Envtl. Conservation
v.
EPA,
540 U.S. 461, 485, 490 (2004).

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 RHR at 40 CFR 51.3108(f)(2)(iv) separately provides five “additional factors”
27

that states must consider in developing their long-term strategies: (1) Emission reductions due to ongoing air pollution control programs, including measures to address reasonably attributable visibility impairment; (2) measures to reduce the impacts of construction activities; (3) source retirement and replacement schedules; (4) basic smoke management practices for prescribed fire used for agricultural and wildland vegetation management purposes and smoke management programs; and (5) the anticipated net effect on visibility due to projected changes in point, area, and mobile source emissions over the period addressed by the long-term strategy. 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. See 2019 Guidance at 21. 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 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. States can, however, consider these factors in a more tailored manner,
e.g.,
in choosing between multiple control options when all are reasonable based on the four statutory factors.
28

2021 Clarifications Memo at 13.

27
The five “additional factors” for consideration in § 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.

28
In particular, 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-RPO consultation and the development of regional emissions strategies; additional consultations between states outside of RPO 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. 40 CFR 51.308(f)(2)(ii)(A). Additionally, the RHR requires that states that contribute to visibility impairment at the same Class I area consider the emission reduction measures the other contributing states have identified as being necessary to make reasonable progress for their own sources. 40 CFR 51.308(f)(2)(ii)(B). If a state has been asked to consider or adopt certain emission reduction measures, but ultimately determines

those measures are not necessary to make reasonable progress, that state must document in its SIP the actions taken to resolve the disagreement. 40 CFR 51.308(f)(2)(ii)(C). 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. See
id.;
2019 Guidance at 53. Under all circumstances, a state must document in its SIP submission all substantive consultations with other contributing states. 40 CFR 51.308(f)(2)(ii)(C).

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.” (82 FR 3091, Jan. 10, 2017). 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.
See
40 CFR 51.308(f)(3)(iii) through (iv). States in which Class I areas are located must establish two RPGs, 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. 40 CFR 51.308(f)(3)(i). The two RPGs 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.
29

The RPGs also account for the projected impacts of implementing other CAA requirements, including non-SIP based requirements. Because RPGs are the modeled result of the measures in states' long-term strategies (as well as other measures required under the CAA), they cannot be determined before states have conducted their four-factor analyses and determined the control measures that are necessary to make reasonable progress. See 2021 Clarifications Memo at 6.

29
RPGs 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 RPGs 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 RPG calculations when states are developing their long-term strategies on disparate schedules, as well as for adjusting RPGs using a post-modeling approach. 2019 Guidance at 47-48.

For the second implementation period, the RPGs are set for 2028. Reasonable progress goals are not enforceable targets, 40 CFR 51.308(f)(3)(iii); rather, they “provide a way for the states to check the projected outcome of the [long-term strategy] against the goals for visibility improvement.” 2019 Guidance at 46. While states are not legally obligated to achieve the visibility conditions described in their RPGs, 40 CFR 51.308(f)(3)(i) requires that “[t]he long-term strategy and the reasonable progress goals must provide for an improvement in visibility for the most impaired days since the baseline period and ensure no degradation in visibility for the clearest days since the baseline period.” 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.
See
40 CFR 51.308(f)(1)(i), (82 FR 3097-98, Jan. 10, 2017).

So that RPGs may also serve as a metric for assessing the amount of progress a state is making towards the national visibility goal, the RHR requires states with Class I areas to compare the 2028 RPG for the most impaired days to the corresponding point on the URP line (representing visibility conditions in 2028 if visibility were to improve at a linear rate from conditions in the baseline period of 2000-2004 to natural visibility conditions in 2064). If the most impaired days RPG in 2028 is above the URP (
i.e.,
if visibility conditions are improving more slowly than the rate described by the URP), each state that contributes to visibility impairment in the Class I area must demonstrate, based on the four-factor analysis required under 40 CFR 51.308(f)(2)(i), that no additional emission reduction measures would be reasonable to include in its long-term strategy. 40 CFR 51.308(f)(3)(ii). To this end, 40 CFR 51.308(f)(3)(ii) requires that each state contributing to visibility impairment in a Class I area that is projected to improve more slowly than the URP provide, “a robust demonstration, including documenting the criteria used to determine which sources or groups [of] sources were evaluated and how the four factors required by paragraph (f)(2)(i) were taken into consideration in selecting the measures for inclusion in its long-term strategy.” The 2019 Guidance provides suggestions about how such a “robust demonstration” might be conducted. See 2019 Guidance at 50-51.

The 2017 RHR, 2019 Guidance, and 2021 Clarifications Memo also explain that projecting an RPG that is on or below the URP 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 CAA's and RHR's requirement that all states must conduct a four-factor analysis to determine what emission reduction measures constitute reasonable progress. The URP 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 URP 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.”
See
82 FR 3093, 3099-3100 (Jan. 10, 2017); 2019 Guidance at 22; 2021 Clarifications Memo at 15-16.

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 subsection apply either to states with Class I areas within their borders, states with no Class I areas but that are reasonably anticipated to cause or contribute to visibility impairment in any Class I area, or both. 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. 40

CFR 51.308(f)(6), (f)(6)(i), (f)(6)(iv). 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.

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. 40 CFR 51.308(f)(6)(ii), (iii).
S
ection 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 Agency's evaluation of a SIP revision.
30

All states' SIPs must also provide for any other elements, including reporting, recordkeeping, and other measures, that are necessary for states to assess and report on visibility. 40 CFR 51.308(f)(6)(vi). Per the 2019 Guidance, a state may note in its regional haze SIP that its compliance with the Air Emissions Reporting Rule (AERR) 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 RPGs for its own and nearby Class I areas.
31

30

See
“Step 8: Additional requirements for regional haze SIPs” in 2019 Regional Haze Guidance at 55.

31

Id.

Separate from the requirements related to monitoring for regional haze purposes under 40 CFR 51.308(f)(6), the RHR 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.”
32

Under this provision, if the EPA or the FLM 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.

32
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.
See
81 FR 26942, 26950 (May 4, 2016); 82 FR 3119 (January 10, 2017). 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. 40 CFR 51.308(g)(1) and (2).

A core component of the progress report requirements is an assessment of changes in visibility conditions on the 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), and then to calculate the difference between those current conditions and baseline (2000-2004) visibility conditions in order to assess progress made to date.
See
40 CFR 51.308(g)(3)(ii). 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.
See
40 CFR 51.308(g)(3)(iii), (f)(5). Since different states submitted their first implementation period progress reports at different times, the starting point for this assessment will vary state by state.

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.
See
40 CFR 51.308(g)(4), (f)(5). 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.

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 FLM or FLMs; pursuant to that consultation, the state must include a summary of the FLMs' conclusions and recommendations in the notice to the public. Consistent with this statutory requirement, the RHR also requires that states “provide the [FLM] with an opportunity for consultation, in person and at a point early enough in the State's policy analyses of its long-term strategy emission reduction obligation so that information and recommendations provided by the [FLM] can meaningfully inform the State's decisions on the long-term strategy.” 40 CFR 51.308(i)(2). Consultation that occurs 120 days prior to any public hearing or public comment opportunity will be deemed “early enough,” but the RHR 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 FLMs 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. 40 CFR 51.308(i)(2). In order for the EPA to evaluate whether FLM consultation meeting the requirements of the RHR has occurred, the SIP submission should include documentation of the timing and content of such consultation. The SIP revision submitted to the EPA must also describe how the state addressed any comments provided by the FLMs. 40 CFR 51.308(i)(3). Finally, a SIP revision must provide procedures for

continuing consultation between the state and FLMs regarding the state's visibility protection program, including development and review of SIP revisions, five-year progress reports, and the implementation of other programs having the potential to contribute to impairment of visibility in Class I areas. 40 CFR 51.308(i)(4).

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

A. Background on New York's First Implementation Period SIP Submission

NYSDEC submitted its regional haze SIP for the first implementation period to the EPA on March 15, 2010, and supplemented it on August 2, 2010, April 16, 2012, and July 2, 2012. The EPA approved New York's first implementation period regional haze SIP submission on August 28, 2012 (77 FR 51915). EPA's approval included, but was not limited to, seventeen source-specific SIP revisions containing permits for Best Available Retrofit Technology, revisions to Title 6 of the New York Codes, Rules and Regulations (NYCRR), Part 249, “Best Available Retrofit Technology (BART),” and revisions to section 19-0325 of the New York Environmental Conservation Law which regulates the sulfur content of fuel oil. Although New York State addressed most of the issues identified in EPA's proposal, EPA promulgated a Federal Implementation Plan to address two sources for which EPA disapproved New York's BART determinations. The requirements for regional haze SIPs for the first implementation period are contained in 40 CFR 51.308(d) and (e) and 40 CFR 51.308(b). Pursuant to 40 CFR 51.308(g), New York was also responsible for submitting a five-year progress report as a SIP revision for the first implementation period, which NYSDEC did on June 16, 2015. The EPA approved the progress report into the New York SIP on September 29, 2017 (82 FR 45499, September 29, 2017).

B. New York's Second Implementation Period SIP Submission and the EPA's Evaluation

In accordance with CAA sections 169A and the RHR at 40 CFR 51.308(f), on May 12, 2020,
33

NYSDEC submitted a revision to the New York SIP to address the jurisdiction's regional haze obligations for the second implementation period, which runs through 2028. New York made its 2020 Regional Haze SIP submission available for public comment on August 7, 2019. NYSDEC received and responded to public comments and included the comments and responses to those comments in their submission to the EPA.

33
NYSDEC supplemented its SIP submission on February 16, 2022.

The following sections describe New York's SIP submission, including analyses conducted by MANE-VU and New York's determinations based on those analyses, New York's assessment of progress made since the first implementation period in reducing emissions of visibility impairing pollutants, and the visibility improvement progress at nearby Class I areas. This notice also contains EPA's evaluation of New York's submission against the requirements of the CAA and RHR for the second implementation period of the regional haze program.

C. Identification of Class I Areas

Section 169A(b)(2) of the CAA requires each state in which any Class I area is located, or “the emissions from which may reasonably be anticipated to cause or contribute to any impairment of visibility” in a Class I area, to have a plan for making reasonable progress toward the national visibility goal. The RHR incorporates this statutory requirement at 40 CFR 51.308(f), which provides that each state's plan “must address regional haze in each mandatory Class I Federal area located within the State and in each mandatory Class I Federal area located outside the State that may be affected by emissions from within the State,” and (f)(2), which requires each state's plan to include a long-term strategy that addresses regional haze in such Class I areas.

The EPA explained in the 1999 RHR preamble that the CAA section 169A(b)(2) requirement that states submit SIPs to address visibility impairment establishes “an `extremely low triggering threshold' in determining which States should submit SIPs for regional haze.” (64 FR 35721, July 1, 1999). In concluding that each of the contiguous 48 states and the District of Columbia meet this threshold,
34

the EPA relied on “a large body of evidence demonstrating that long-range transport of fine PM contributes to regional haze,”
id.,
including modeling studies that “preliminarily demonstrated that each State not having a Class I area had emissions contributing to impairment in at least one downwind Class I area.”
Id.
at 35722. In addition to the technical evidence supporting a conclusion that each state contributes to
existing
visibility impairment, the EPA also explained that the second half of the national visibility goal—preventing
future
visibility impairment—requires having a framework in place to address future growth in visibility-impairing emissions and makes it inappropriate to “establish criteria for excluding States or geographic areas from consideration as potential contributors to regional haze visibility impairment.”
Id.
at 35721. Thus, the EPA concluded that the agency's “statutory authority and the scientific evidence are sufficient to require all States to develop regional haze SIPs to ensure the prevention of any future impairment of visibility, and to conduct further analyses to determine whether additional control measures are needed to ensure reasonable progress in remedying existing impairment in downwind Class I areas.”
Id.
at 35722. EPA's 2017 revisions to the RHR did not disturb this conclusion.
See
82 FR 3094 (July 10, 2017).

34
EPA determined that “there is more than sufficient evidence to support our conclusion that emissions from each of the 48 contiguous states and the District of Columbia may reasonably be anticipated to cause or contribute to visibility impairment in a Class I area.” (64 FR 35721, July 1, 1999). Hawaii, Alaska, and the U.S. Virgin Islands must also submit regional haze SIPs because they contain Class I areas.

New York has no Class I areas within its borders. For the second implementation period, MANE-VU performed technical analyses
35

to help inform source and state-level contributions to visibility impairment and the need for interstate consultation. MANE-VU used the results of these analyses to determine which states' emissions “have a high likelihood of affecting visibility in MANE-VU's Class I areas.”
36

Similar to metrics used in the first implementation period,
37

MANE-VU used a greater than 2 percent of sulfate plus nitrate emissions contribution criteria to determine whether emissions from individual jurisdictions within the region affected visibility in any Class I areas. The MANE-VU analyses for the second implementation period used a combination of data analysis techniques, including emissions data dispersion modeling. Although many of the analyses focused only on SO
2
emissions and resultant particulate sulfate contributions to visibility impairment, some also incorporated NO
X
emissions to estimate particulate nitrate contributions.

35
The contribution assessment methodologies for MANE-VU Class I areas are summarized in appendix C of the NY RH 2nd Implementation Period SIP submission, “Selection of States for MANE-VU Regional Haze Consultation (2018).”

36
Id.

37

See
docket EPA-R02-OAR-2012-0296 for MANE-VU supporting materials.

One MANE-VU analysis used for contribution assessment was CALPUFF

air dispersion modeling.
38

The CALPUFF model was used to estimate sulfate and nitrate formation and transport in MANE-VU and nearby regions from large electric generating unit (EGU) point sources and other large industrial and institutional sources in the eastern and central United States. Information from the initial round of CALPUFF modeling was collected on the 444 electric generating units (EGUs) that were determined to warrant further scrutiny based on their emissions of SO
2
and NO
X
. The list of EGUs was based on enhanced “Q/d” analysis
39

that considered recent SO
2
emissions in the eastern United States and an analysis that adjusted previous 2002 MANE-VU CALPUFF modeling by applying a ratio of the 2011 to 2002 SO
2
emissions. This list of sources was then enhanced by including the top five SO
2
and NO
X
emission sources for 2011 for each state included in the modeling domain. A total of 311 EGU stacks (as opposed to individual units) were included in the CALPUFF modeling analysis. Initial information was also collected on the 50 industrial and institutional sources that, according to the 2011 Q/d analysis, contributed the most to visibility impacts in each Class I area. The ultimate CALPUFF modeling run included a total of 311 EGU stacks and 82 industrial facilities. The summary report for the CALPUFF modeling included the top 10 most impacting EGUs and the top five most impacting industrial/institutional sources for each Class I area and compiled those results into a ranked list of the most impacting EGUs and industrial sources at MANE-VU Class I areas.
40

38

See
page 6 of Appendix K of the NY RH 2nd Implementation Period SIP submission.

39
“Q/d” is emissions (Q) in tons per year, typically of one or a combination of visibility-impairing pollutants, divided by 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.

40

See
Tables 34 and 35 of appendix K of the NY RH 2nd Implementation Period SIP submission.

New York had three EGUs and four industrial sources that were included in the MANE-VU CALPUFF modeling.
41

Somerset Operating Company, Oswego Harbor Power, and Cayuga Operating Company are the three EGU facilities identified by the modeling. Lafarge Building Materials Inc., Finch Paper LLC, International Paper Ticonderoga Mill, and Kodak Park Division are the four industrial/institutional (ICI) facilities identified by the modeling.

41

See
appendix K, “MANE-VU Source Contribution Modeling Report—CALPUFF Modeling of Large Electrical Generating Units and Industrial Sources (MANE-VU, April 2017)” of the NY RH 2nd Implementation Period SIP submission.

In its submittal, New York states that it has adopted revisions to 6 NYCRR Part 251, Carbon Dioxide Performance Standards for Major Electric Generating Facilities “to require all power plants in New York to meet new emissions limits for carbon dioxide (CO
2
).” As a result of these revisions, New York's submittal indicates that Somerset Operating Company ceased operations after submitting their deactivation plan to New York Independent System Operator (NYISO). In its February 16, 2022, supplement to its submittal, New York stated that Somerset Operating Company retired its primary units on March 31, 2020 and that it was being demolished.
42

New York's submittal addresses Oswego Harbor Power as follows. Oswego Harbor Power Emission Unit U00006 consists of one steam generator, Unit 6, that provides steam to a turbine capable of producing 850 MW net of electricity. This unit can produce up to 245 MW by firing natural gas. Natural gas or distillate oil may be used to ignite the boiler during startup. The oil must have a sulfur content no greater than 0.5% by weight to be used in this unit. Unit 6 is subject to 40 CFR part 60, subpart D. Particulate emissions are controlled by an electrostatic precipitator (S006C). NO
X
emissions are controlled by over-fire air and flue gas recirculation. SO
2
emissions in 2017 were 100.9 tons, compared to 373.4 tons in 2011. NO
X
emissions from Oswego Harbor Power were 59.7 tons, a decrease from 101.6 tons in 2011. New York's submittal indicates that Cayuga Generating Station is no longer operating, but still retains its State Administrative Procedure Act (SAPA)
43

extended permit.

42

See
docket document “FLM List Facility Controls”

43
N.Y. Comp. Codes R. & Regs. tit. 82.

International Paper Ticonderoga Mill submitted an updated RACT analysis in September 2016 which set an emission limit of 0.23 lb NO
X
/MMBtu on the power boiler that burns natural gas. RED-Rochester is located in the old Kodak Park and has converted coal-fired boiler #44 to natural gas with #2 fuel oil backup. Boiler #44 is rated at 694 MMBtu/hr on natural gas and 670 MMBtu/hr on No. 2 oil. The final conversion scenario decommissioned three boilers:
44

the previously shut down 640 MBTU/hr coal fired Boiler 41, the 670 MBTU/hr coal fired Boiler 42 in March 2018, and the 640 MBTU/hr coal-fired Boiler 43 in March 2018. Four operating 98 MBTU/hr #6 fuel oil fired package boilers have been retained as limited use boilers. New York also asserts that the new natural gas boilers will significantly reduce both NO
X
and SO
2
emissions compared to historical and NPS estimated emissions from the coal boilers. Finally, Lafarge Building Materials, Inc. and Finch Paper, LLC were selected for further analysis as part of the long-term strategy and will be discussed in a later section of this proposed rulemaking.

44
RED-Rochester LLC Air Title V Permit. Available at
https://www.dec.ny.gov/dardata/boss/afs/permits/826990012600001_r1.pdf.

The second MANE-VU contribution analysis used a meteorologically weighted Q/d calculation to assess states' contributions to visibility impairment at MANE-VU Class I areas.
45

This analysis focused predominantly on SO
2
emissions and used the quantity of cumulative SO
2
emissions from a source for the variable of “Q,” and the distance of the source or state to the IMPROVE monitor receptor at a Class I area as “d.” The result is then multiplied by a constant (C
i
), which is determined based on the prevailing wind patterns. MANE-VU selected a meteorologically weighted Q/d analysis as an inexpensive initial screening tool that could easily be repeated to determine which states, sectors, or sources have a larger relative impact and warrant further analysis. MANE-VU's analysis estimated New York's maximum sulfate contribution was 4.66% at any Class I area based on the maximum daily impact. The largest impacts from New York's sulfate contributions were to Lye Brook Wilderness, Vermont. Although MANE-VU did not originally estimate nitrate impacts, the MANE-VU Q/d analysis was extended to account for nitrate contributions from NOx emissions and to approximate the nitrate impacts from area and mobile sources. MANE-VU therefore developed a ratio of nitrate to sulfate impacts based on the previously described CALPUFF modeling and applied those to the sulfate Q/d results in order to derive nitrate contribution estimates. Several states did not have CALPUFF nitrate to sulfate ratio results, however, because there were no point sources modeled with CALPUFF.

45
The methodology used by MANE-VU for the meteorological weighted Q/d analysis can be found in Appendix O of the NY RH 2nd Implementation Period SIP submission, “MANE-VU Updated Q/d*C Contribution Assessment.”

In order to develop a final set of contribution estimates, MANE-VU weighted the results from both the Q/d and CALPUFF analyses. The MANE-VU mass-weighted sulfate and nitrate contribution results were reported for the MANE-VU Class I areas (the Q/d summary report included results for

several non-MANE-VU areas as well). If a state's contribution to sulfate and nitrate concentrations at a particular Class I area was 2 percent or greater, MANE-VU regarded the state as contributing to visibility impairment in the area. According to MANE-VU's analyses, sources in New York have been found to contribute to visibility impairment in downwind mandatory Class I areas. These mandatory Class I areas are: Lye Brook Wilderness Area, Vermont; Brigantine Wildlife Refuge, New Jersey; Presidential Range-Dry River Wilderness Area and Great Gulf Wilderness Area, New Hampshire; Roosevelt-Campobello International Park, Acadia National Park and Moosehorn Wildlife Refuge, Maine; Dolly Sods Wilderness Area and Otter Creek Wilderness Area, West Virginia; and Shenandoah National Park, Virginia. The largest New York mass-weighted sulfate and nitrate contribution to any Class I area was 10.0% to Lye Brook Wilderness.
46

Thus, New York concludes in its regional haze submission, that it does contribute to visibility impairment in Class I Federal areas, and that its contributions “while important, are not the most significant, with the contributions of several states [Midwest RPO and VISTAS] outside the MANE-VU region being significantly larger than New York's.”
47

46

See
Pennsylvania's contribution of 20.0% in Table 10-1, “Percent Mass-Weighted Sulfate and Nitrate Due to Emissions from Listed States,” of the NY RH 2nd Implementation Period SIP submittal.

47

See
Section 10.2.2 of the NY RH 2nd Implementation Period SIP submittal and Appendix C: “Selection of States for MANE-VU Regional Haze Consultation (2018).”

As explained above, the EPA concluded in the 1999 RHR that “all [s]tates contain sources whose emissions are reasonably anticipated to contribute to regional haze in a Class I area,” (64 FR 35721, July 1, 1999), and this determination was not changed in the 2017 RHR. Critically, the statute and regulation both require that the cause-or-contribute assessment consider all emissions of visibility-impairing pollutants from a state, as opposed to emissions of a particular pollutant or emissions from a certain set of sources. Consistent with these requirements, the 2019 Guidance makes it clear that “all types of anthropogenic sources are to be included in the determination” of whether a state's emissions are reasonably anticipated to result in any visibility impairment. 2019 Guidance at 8.

The EPA notes that the screening analyses on which MANE-VU relied are useful for certain purposes. MANE-VU used information from its technical analysis to rank the largest contributing states to sulfate and nitrate impairment in five Class I areas within MANE-VU states and three additional, nearby Class I areas.
48

The rankings were used to determine upwind states that were deemed important to include in state-to-state consultation (based on an identified impact screening threshold). Additionally, large individual source impacts were used to address specific components of MANE-VU's control analysis “Asks”
49

of states and sources within and upwind of MANE-VU.
50

The EPA finds the nature of the analyses generally appropriate to support decisions on states with which to consult. However, we have cautioned that source selection methodologies that target the largest regional contributors to visibility impairment across multiple states may not be reasonable for a particular state if it results in few or no sources being selected. 2021 Clarifications Memo at 3.

48
The Class I areas analyzed were Acadia National Park in Maine, Brigantine Wilderness in New Jersey, Great Gulf Wilderness in New Hampshire, Lye Brook Wilderness in Vermont, Moosehorn Wilderness in Maine, Shenandoah National Park in Virginia, James River Face Wilderness in Virginia, and Dolly Sods/Otter Creek Wildernesses in West Virginia.

49
As explained more fully in Section IV.E.a, MANE-VU refers to each of the components of its overall strategy as an “Ask “of its member states.

50
The MANE-VU consultation report (Appendix E of the NY RH 2nd Implementation Period SIP submission) explains that “[t]he objective of this technical work was to identify states and sources from which MANE-VU will pursue further analysis. This screening was intended to identify which states to invite to consultation, not a definitive list of which states are contributing.”

Further, the EPA reviewed the adequacy of MANE-VU's analysis and determinations regarding New York's contribution to visibility impairment at out-of-state Class I areas. The MANE-VU technical work focuses on the magnitude of visibility impacts from certain New York emissions on nearby Class I areas. However, the analyses did not account for all emissions and all components of visibility impairment (
e.g.,
primary PM emissions, and impairment from fine PM, elemental carbon, and organic carbon). In addition, Q/d analyses with a relatively simplistic accounting for wind trajectories and CALPUFF applied to a very limited set of EGUs and major industrial sources of SO
2
and NO
X
are not scientifically rigorous tools capable of evaluating contribution to visibility impairment from
all
emissions in a state. Although New York noted that the contributions from several states outside the MANE-VU region are significantly larger than its own, we again clarify that each state is obligated under the CAA and Regional Haze Rule to address regional haze visibility impairment resulting from emissions from within the state, irrespective of whether another state's contribution is greater. See 2021 Clarifications Memo at 3. Additionally, we note that the 2 percent or greater sulfate-plus-nitrate threshold used to determine whether New York emissions contribute to visibility impairment at a particular Class I area may be higher than what EPA believes is an “extremely low triggering threshold” intended by the statute and regulations. In sum, based on the information provided, emissions from New York contribute to visibility impairment in Class I areas in Maine, New Jersey, New Hampshire, Vermont, Virginia, and West Virginia.
51

The EPA generally agrees with this conclusion. However, due to the low triggering threshold implied by the Rule and the lack of rigorous modeling analyses, we do not necessarily agree with the level of the State's 2% contribution threshold as a general matter.

51

See
Section 1.4, “Mandatory Class I Federal Areas Affected by New York State” of the NY RH 2nd Implementation Period SIP submission.

Regardless, we note that New York did determine that sources and emissions within the State contribute to visibility impairment at out-of-state Class I areas. Furthermore, New York took part in the emission control strategy consultation process as a member of MANE-VU. As part of that process, MANE-VU developed a set of emissions reduction measures identified as being necessary to make reasonable progress in the five MANE-VU Class I areas. MANE-VU refers to each component of its overall strategy as an “Ask” of participating states. This strategy consists of six “Asks” for states within MANE-VU, and five Asks for states outside the region that were found to impact visibility at Class I areas within MANE-VU.
52

New York's submission discusses each of the Asks and explains why or why not each is applicable and how it has complied with the relevant components of the emissions control strategy MANE-VU has laid out for its states. New York worked with MANE-VU to determine potential reasonable measures that could be implemented by 2028, considering the cost of compliance, the time necessary for compliance, the energy and non-air quality

environmental impacts, and the remaining useful life of any potentially affected sources. Although we have concerns regarding some aspects of MANE-VU's technical analyses supporting states' contribution determinations as a general matter, we propose to find that New York has nevertheless satisfied the applicable requirements for making reasonable progress towards natural visibility conditions in Class I areas that may be affected be emissions from the state.

52

See
appendix H of the NY RH 2nd Implementation Period SIP submission, “Statement of the Mid-Atlantic/Northeast Visibility Union (MANE-VU) Concerning a Course of Action within MANE-VU toward Assuring Reasonable Progress for the Second Regional Haze Implementation Period (2018-2028), (August 2017).”

Specifically, as discussed in further detail below, the EPA is proposing to find that New York has submitted a regional haze plan that meets the requirements of 40 CFR 51.308(f)(2) related to the development of a long-term strategy.

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

Section 51.308(f)(1) requires states to determine the following for “each mandatory Class I Federal area located within the State”: baseline visibility conditions for the most impaired and clearest days, natural visibility conditions for the most impaired and clearest days, progress to date for the most impaired and clearest days, the differences between current visibility conditions and natural visibility conditions, and the URP. This section also provides the option for states to propose adjustments to the URP line for a Class I area to account for impacts from anthropogenic sources outside the United States and/or the impacts from wildland prescribed fires that were conducted for certain, specified objectives. 40 CFR 51.308(f)(1)(vi)(B).

Because New York does not have any Class I areas within its borders, it is not required to calculate baseline, current, and natural visibility conditions, or to calculate a URP.
53

Thus, the EPA finds that the requirements under this section have been satisfied by New York.

53
While New York noted that it was not required to comply with 40 CFR 51.308(f)(1), elsewhere in its SIP submission (
See
section 5) it included visibility metrics of nearby Class I areas, which were taken from, “Mid-Atlantic/Northeast U.S. Visibility Data 2004-2016 (2nd RH SIP Metrics) (MANE-VU, August 2018).”

E. Long-Term Strategy for Regional Haze

Each state having a Class I area within its borders or emissions that may affect visibility in a Class I area must develop a long-term strategy for making reasonable progress towards the national visibility goal. CAA 169A(b)(2)(B). As explained in the Background section of this notice, 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. 40 CFR 51.308(f)(2)(i). Each state's long-term strategy must include the enforceable emission limitations, compliance schedules, and other measures that are necessary to make reasonable progress. 40 CFR 51.308(f)(2). 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 is that no new measures are reasonable for a source, that source's existing measures are necessary to make reasonable progress, and must therefore be included in the SIP, 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, states must also consider the five additional factors in 40 CFR 51.308(f)(2)(iv). As part of its reasonable progress determination, the state must describe the criteria used to determine which sources or group of sources were evaluated (
i.e.,
subjected to four-factor analysis) for the second implementation period and how the four factors were taken into consideration in selecting the emission reduction measures for inclusion in the long-term strategy. 40 CFR 51.308(f)(2)(iii).

The following subsections summarize how New York's SIP submission addressed the requirements of 40 CFR 51.308(f)(2)(i). As explained above, New York relied on MANE-VU's technical analyses and framework (
i.e.,
the Asks), in addition to their review of sources identified by FLMs, to form the basis of its long-term strategy to address reasonable progress. Thus, section IV.E.a., “New York's Response to the Six MANE-VU Asks,” describes MANE-VU's development of the six Asks and how New York addressed each. Section IV.E.b., “The EPA's Evaluation of New York's Response to the Six MANE-VU Asks and Compliance with 40 CFR 51.308(f)(2)(i),” then discusses EPA's evaluation of New York's SIP revision with regard to the same.

a. New York's Response to the Six MANE-VU Asks

States may rely on technical information developed by the RPOs of which they are members to select sources for four-factor analysis and to conduct that analysis, as well as to satisfy the documentation requirements under 40 CFR 51.308(f). Where an RPO 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 RPO'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 RPO process have approved the technical analyses. 40 CFR 51.308(f)(3)(iii). States may also satisfy the requirement of 40 CFR 51.308(f)(2)(ii) to engage in interstate consultation with other states that have emissions that are reasonably anticipated to contribute to visibility impairment in a given Class I area under the auspices of intra- and inter-RPO engagement.

New York is a member of the MANE-VU RPO and participated in the RPO's regional approach to developing a strategy for making reasonable progress towards the national visibility goal in the MANE-VU Class I areas. MANE-VU's strategy includes a combination of (1) measures for certain source sectors and groups of sectors that the RPO determined were reasonable for states to pursue, and (2) a request for member states to conduct four-factor analyses for individual sources that it identified as contributing to visibility impairment. As described above, MANE-VU refers to each of the components of its overall strategy as an Ask of its member states. On August 25, 2017, the Executive Director of MANE-VU, on behalf of the MANE-VU states and Tribal nations, signed a statement that identifies six emission reduction measures that comprise the Asks for the second implementation period.
54

The Asks were “designed to identify reasonable emission reduction strategies that must be addressed by the states and Tribal nations of MANE-VU through their regional haze SIP updates.”
55

The statement explains that “[i]f any State cannot agree with or complete a Class I

State's Asks, the State must describe the actions taken to resolve the disagreement in the Regional Haze SIP.”
56

54

See
appendix H of the NY RH 2nd Implementation Period SIP submission, “Statement of the Mid-Atlantic/Northeast Visibility Union (MANE-VU) States Concerning a Course of Action Within MANE-VU Toward Assuring Reasonable Progress for the Second Regional Haze Implementation Period (2018-2028)” at 1, August 25, 2017.

55
Id.

56
Id.

MANE-VU's recommendations as to the appropriate control measures were based on technical analyses documented in the RPO's reports and included as appendices to or referenced in New York's regional haze SIP submission. One of the initial steps of MANE-VU's technical analysis was to determine which visibility-impairing pollutants should be the focus of its efforts for the second implementation period. In the first implementation period, MANE-VU determined that sulfates were the most significant visibility impairing pollutant at the region's Class I areas. To determine the impact of certain pollutants on visibility at Class I areas for the purpose of second implementation period planning, MANE-VU conducted an analysis comparing the pollutant contribution on the clearest and most impaired days in the baseline period (2000-2004) to the most recent period (2012-2016)
57

at MANE-VU and nearby Class I areas. MANE-VU found that while SO
2
emissions were decreasing and visibility was improving, sulfates still made up the most significant contribution to visibility impairment at MANE-VU and nearby Class I areas. According to the analysis, NO
X
emissions have begun to play a more significant role in visibility impacts in recent years as SO
2
emissions have decreased. The technical analyses used by New York are included in their submission to the EPA and are as follows:

57
The period of 2012-2016 was the most recent period for which data was available at the time of analysis.

• 2016 Updates to the Assessment of Reasonable Progress for Regional Haze in MANE-VU Class I Areas (Appendix M);

• 2016 MANE-VU Source Contribution Modeling Report—CALPUFF Modeling of Large Electrical Generating Units and Industrial Sources April 4, 2017 (Appendix K);

• Regional Haze Metrics Trends and HYSPLIT Trajectory Analyses. May 2017. (Appendix L);

• Selection of States for MANE-VU Regional Haze Consultation (2018) (MANE-VU Technical Support Committee. September 2017. (Appendix C); and

Furthermore, technical analyses New York's submission also references, but New York did not include within its submission, include the following documents:

• Technical Support Document for the 2011 Ozone Transport Commission/Mid-Atlantic Northeastern Visibility Union Modeling Platform (Ozone Transport Commission, September 2018);

• Impact of Wintertime SCR/SNCR Optimization on Visibility Impairing Nitrate Precursor Emissions (prepared by the MANE-VU Technical Support Committee, November 20, 2017); and

• Technical Memorandum: Four Factor Data Collection (prepared by MANE-VU Technical Support Committee March 30, 2017).

To support development of the Asks, MANE-VU gathered information on each of the four factors for six source sectors it determined, based on an examination of annual emission inventories, “had emissions that were reasonabl[y] anticipated to contribute to visibility degradation in MANE-VU:” electric generating units (EGUs), industrial/commercial/institutional boilers (ICI boilers), cement kilns, heating oil, residential wood combustion, and outdoor wood combustion.
58

MANE-VU also collected data on individual sources within the EGU, ICI boiler, and cement kiln sectors.
59

Information for the six sectors included explanations of technically feasible control options for SO
2
or NO
X
, illustrative cost-effectiveness estimates for a range of model units and control options, sector-wide cost considerations, potential time frames for compliance with control options, potential energy and non-air-quality environmental impacts of certain control options, and how the remaining useful lives of sources might be considered in a control analysis.
60

Source-specific data included SO
2
emissions
61

and existing controls
62

for certain existing EGUs, ICI boilers, and cement kilns. MANE-VU considered this information on the four factors as well as the analyses developed by the RPO's Technical Support Committee when it determined specific emission reduction measures that were found to be reasonable for certain sources within two of the sectors it had examined—EGUs and ICI boilers. The Asks were based on this analysis and looked to either optimize the use of existing controls, have states conduct further analysis on EGU or ICI boilers with considerable visibility impacts, implement low sulfur fuel standards, or lock-in lower emission rates.

58
MANE-VU Four Factor Data Collection Memo at 1, March 30, 2017,
available at https://otcair.org/MANEVU/Upload/Publication/Reports/Four-Factor%20Data%20Collection%20Memo%20-%20170314.pdf.
The six sectors were identified in the first implementation period pursuant to MANE-VU's contribution assessment; MANE-VU subsequently updated its information on these sectors for the second implementation period.

59

See
appendix M of the NY RH 2nd Implementation Period SIP submission, “2016 Updates to the Assessment of Reasonable Progress for Regional Haze in MANE-VU Class I Areas, Jan. 31, 2016.”

60
Id.

61
Table 1 of MANE-VU's “Four Factor Data Collection Memo” March 30, 2017 contains 2011 SO
2
data from specific sources.

62
The “Status of the Top 167 Electric Generating Units (EGUs) that Contributed to Visibility Impairment at MANE-VU Class I Areas during the 2008 Regional Haze Planning Period,” July 25, 2016, reviews the existing and soon to be installed, at the time of the report, emission controls at individual EGU sources that were a part of the MANE-VU Ask from the first implementation period. Available at:
https://otcair.org/MANEVU/Upload/Publication/Reports/Status%20of%20the%20Top%20167%20Stacks%20from%20the%202008%20MANE-VU%20Ask.pdf.

MANE-VU Ask 1 is “ensuring the most effective use of control technologies on a year-round basis” at EGUs with a nameplate capacity larger than or equal to 25 megawatts (MW) with already installed NO
X
and/or SO
2
controls.
63

In its submission, New York explained that the control limits required by its Reasonably Available Control Technology (RACT) rule, SIP-approved 6 NYCRR subpart 227-2, “Reasonably Available Control Technology (RACT) for Major Facilities of Oxides of Nitrogen (NO
X
),” include year-round emission limits of NO
X
for EGUs with a nameplate capacity larger than or equal to 25 MW.
64

Regarding control of SO
2
emissions, under 6 NYCRR subpart 225, “Fuel Consumption and Use,” which was last approved by the EPA on August 23, 2018 (
See
83 FR 42589), any stationary combustion installation that fires solid or liquid fuels is required to meet the sulfur-in-fuel standards of the subpart.
65

Additionally, New York explained that the SIP-approved 6 NYCRR Part 245, “CSAPR SO
2
Group 1 Trading Program” (
See
84 FR 38878), will distribute Federal SO
2
CSAPR allowances to EGUs for the purpose of reducing PM
2.5
in New York State and downwind states by limiting emissions of SO
2
year-round from fossil fuel-fired EGUs. Thus, based on the information regarding SIP-approved 6 NYCRR Parts 225, 227, and 245, New York explains that its operating permits for EGUs, including

those which are for EGUs with a nameplate capacity larger than or equal to 25 MW, require that controls be run year-round for both NO
X
and SO
2
by setting emission limits in permits that reflect the emission levels when the controls are in operation to ensure the most effective use of control technologies. New York therefore concluded that it is meeting Ask 1.

63

See
appendix H of the NY RH 2nd Implementation Period SIP submission.

64

See
NYCRR Part 227-2, “Reasonably Available Control Technology (RACT) for Major Facilities of Oxides of Nitrogen (NO
X
),” which applies to all EGUs and sets emission limits that can only be achieved with year-round operation of controls.

65
New York submitted additional revisions to 6 NYCRR 225-1. The EPA proposed approval. 87 FR 64428 (October 25, 2022).

MANE-VU Ask 2 consists of a request that states “perform a four-factor analysis for reasonable installation or upgrade to emissions controls” for specified sources. MANE-VU developed its Ask 2 list of sources for analysis by performing modeling and identifying facilities with the potential for 3.0 inverse megameters (Mm
-1
) or greater impacts on visibility at any Class I area in the MANE-VU region. Finch Paper and Lafarge Building Materials are the two sources in New York State that were identified by Ask 2.

In section 10.6.3, “Significant Visibility Impact Emission Sources,” of New York's submittal, an analysis addressing each of the four-factors is provided for Finch Paper and Lafarge Building Materials. New York's analysis for Finch Paper determined that the phased-in switch from No. 6 fuel oil to natural gas in their boilers (completed by the end of 2015) and the boiler and combustion tune-ups, consistent with 40 CFR part 63 subpart DDDDD Boiler MACT Rule (especially for boilers 4 and 5), were adequate upgrades to control emissions. Additionally, New York's analysis for Lafarge Building Materials determined that major renovations which included the replacement of the facility's two wet process kilns with a dry process kiln and the installation of a wet scrubber and Selective Non-Catalytic Reduction (SNCR) to the kiln system to be adequate upgrades to control emissions. Both facilities have undergone major updates since the 2011 emissions data was collected, which included the implementation of emission control strategies, resulting in no additional time necessary to comply. Additionally, both facilities have SIP-approved controls installed that limit their potential contribution to visibility impairment.

In addition to the analyses conducted for Finch Paper and Lafarge Building Materials, New York provided information regarding controls and emissions at the facilities within New York that were identified by the FLMs during consultation. The following discussion is related to information New York provided pertaining to FLM concerns.

The Anchor Glass Container Corporation facility in Elmira is subject to a 2018 Consent Decree with EPA that contains a compliance schedule for controls to be implemented on the facility's two furnaces (Elmira 1 and Elmira 2). New York indicated that both furnaces will be rebuilt and will burn oxyfuel or install a selective catalytic reduction (SCR) unit to minimize NO
X
emissions. These controls were implemented for Elmira 1 in 2021. Additionally, a scrubber system and an electrostatic precipitator (ESP) were installed on Elmira 1 in 2021. Elmira 2 underwent batch optimization in 2021 and will burn oxyfuel or install a selective catalytic reduction (SCR) by December 31, 2029.

Moreover, New York indicated that Morton Salt Division converted its boilers from firing coal to natural gas. That said, a new natural gas 148 MMBtu/hr steam boiler and eight small direct fired building heaters replaced an existing 138 MMBtu/hr coal boiler and an existing 92.5 MMBtu/hr natural gas boiler. According to the State, the new natural gas 148 MMBtu/hr steam boiler is subject to the relevant presumptive RACT emission limit of 0.06 pounds NO
X
per million Btu burning only natural gas. Notably, this conversion reduced emissions below the major source threshold and, as a result, the facility's Title V permit was replaced by an Air State Facility permit.
66

66

See
Air State Facility permit at:
https://extapps.dec.ny.gov/data/dar/afs/permits/956320000700045_r0.pdf.

The Bowline Point Generating Station switched to natural gas but will be allowed to burn oil as a backup. Additionally, Lehigh Northeast Cement operates with a dry process, which has fewer emissions than wet processes, and a selective noncatalytic reduction (SNCR) began operation July 2012. Notably, Northport Power Station burned much less #6 high sulfur fuel oil in 2016 and 2017 and, as a result of 6 NYCRR 225-1, “Sulfur-in-fuel limitations,” the sulfur content of #6 fuel oil used at the facility has decreased providing for an additional reduction of SO
2
emissions over the past years.

Furthermore, New York claims that water injection, dry low NO
X
burners, and SCR are used to control NO
X
emissions, along with the use of an oxidation catalyst to control CO and VOC emissions at the Con Edison-East River Generating Station facility. At Ravenswood Generating Station, dry low NO
X
burners and SCR are used to control NO
X
emissions from unit U-CC001. In addition, emissions of VOC and CO are controlled using an oxidation catalyst and New York only allows distillate oil to be burned for 720 hours per year. The Globe Metallurgical, Inc., plant shutdown indefinitely due to market conditions in December 2018. Also, the Roseton Generating Station exclusively burns natural gas during the ozone season and burns natural gas and No. 6 fuel oil during the remainder of the year. PM emission from Units 1 & 2 are controlled with a mechanical dust collector and NO
X
emissions are controlled with “Burners Out Of Service” (BOOS) controls, oil steam atomization, and windbox flue gas recirculation at the Roseton facility.

Moreover, Cargill Salt Co.'s Watkins Glen Plant shutdown four boilers (two coal-fired and two natural gas-fired) in 2013, totaling 228 MMBtu/hr heat input capacity. The four boilers that were shutdown were replaced by one 181 MMBtu/hr natural gas-fired boiler, equipped with a low-NO
X
burner. The replacement boiler is subject to a 0.1 lbs NO
X
/MMBtu heat input limit that is monitored using a Continuous Emissions Monitoring System (CEMS), and as a result of these changes, the plant is no longer considered a major facility subject to a Title V permit. Norlite Corporation has had its permit emission limits reduced from 61 lb/hr of NO
X
and 30 lb/hr of SO
2
in 2011, to 22.4 lb/hr of NO
X
and 28 lb/hr of SO
2
. As a result, NO
X
and SO
2
emissions at Norlite decreased from 80.7 tons in 2011 to 78.8 tons in 2017 and 124.9 tons in 2011 to 60.4 tons in 2017 respectively. New York therefore concluded that it satisfies Ask 2.

Ask 3 is for each MANE-VU state to pursue an ultra low-sulfur fuel oil standard if it has not already done so in the first implementation period.
67

The Ask includes percent by weight standards for #2 distillate oil (0.0015% sulfur by weight or 15 ppm), #4 residual oil (0.25-0.5% sulfur by weight), and #6 residual oil (0.3-0.5% sulfur by weight). New York explains that it has already implemented a low-sulfur fuel standard and does not need to take further action by 2028. In 2018, the EPA approved into the New York SIP New York's regulation to reduce the sulfur content of fuel oil, 6 NYCRR 225-1. 83 FR 42589 (Aug. 23, 2018). The final rule limited firing of all residual oil to a range of 0.3 to 0.5% sulfur by weight depending on the area and a 15 ppm limit (0.0015% sulfur by weight) on #2 oil starting July 1, 2014. The ultra low-sulfur fuel oil regulations in New York are a part of its

long-term strategy. New York therefore concluded that it is meeting Ask 3.

67
MANE-VU's analysis, which New York relied on, is found in “Appendix M-2016 Updates to the Assessment of Reasonable Progress for Regional Haze in MANE-VU Class I Areas.”

MANE-VU Ask 4 requests states to update permits to “lock in” lower emissions rates for NO
X
, SO
2
, and PM at emissions sources larger than 250 million British Thermal Units (MMBtu) per hour heat input that have switched to lower emitting fuels. According to New York's SIP submission, New York updates permits for large point emission sources every five years for Title V facilities, every ten years for Air State Facilities, and whenever both Title V and Air State facilities make a major update. New York explains that it will also require the use of lower emitting fuel in the permits when these permits are updated. Additionally, New York's submittal indicates that it has adopted 6 NYCRR part 251, “CO2 Performance Standards for Major Electric Generating Facilities,” which requires all power plants in New York to meet new emissions limits for carbon dioxide (CO
2
) and will end the use

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2024-06105. Public record. Not legal advice.