178 Federal Register / Vol. 89, No. 1 / Tuesday, January 2, 2024 / Proposed Rules 

1Areas 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. 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 52 

[EPA–R07–OAR–2023–0582; FRL–11576– 

01–R7] 

Air Plan Disapproval; Kansas; 

Regional Haze 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: The Environmental Protection 

Agency (EPA) is proposing to 

disapprove a revision to Kansas’s State 

Implementation Plan (SIP) submitted on 

July 28, 2021, to satisfy applicable 

requirements under the Clean Air Act 

(CAA) and EPA’s Regional Haze Rule 

(RHR) for the program’s second 

planning period. As required by section 

169A of the Clean Air Act, the federal 

Regional Haze Rule calls for state and 

federal agencies to work together to 

improve visibility, including Regional 

Haze, in 156 national parks and 

wilderness areas. The rule requires the 

states, in coordination with the EPA, the 

National Park Service (NPS), U.S. Fish 

and Wildlife Service (FWS), the U.S. 

Forest Service (FS), and other interested 

parties, to develop and implement air 

quality protection plans in which states 

revise their long-term strategies (LTS) 

for making reasonable progress towards 

the national goal of preventing any 

future, and remedying any existing, 

anthropogenic impairment of visibility 

in these mandatory Class I Federal 

Areas. Disapproval does not start a 

mandatory sanctions clock. 

DATES: Comments must be received on 

or before February 1, 2024. 

ADDRESSES: You may send comments, 

identified by Docket ID No. EPA–R07– 

OAR–2023–0582 to https://

www.regulations.gov. Follow the online 

instructions for submitting comments. 

Instructions: All submissions received 

must include the Docket ID No. for this 

rulemaking. Comments received will be 

posted without change to https://

www.regulations.gov/, including any 

personal information provided. For 

detailed instructions on sending 

comments and additional information 

on the rulemaking process, see the 

‘‘Written Comments’’ heading of the 

SUPPLEMENTARY INFORMATION section of 

this document. 

FOR FURTHER INFORMATION CONTACT: Jed 

D. Wolkins, Environmental Protection 

Agency, Region 7 Office, Air Permitting 

and Planning Branch, 11201 Renner 

Boulevard, Lenexa, Kansas 66219; 

telephone number: (913) 551–7588; 

email address: wolkins.jed@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Throughout this document ‘‘we,’’ ‘‘us,’’ 

and ‘‘our’’ refer to the EPA. 

Table of Contents 

I. Written Comments 

II. What is being addressed in this document? 

III. Background and Requirements for 

Regional Haze Plans 

A. Regional Haze Background 

B. Roles of Agencies in Addressing 

Regional Haze 

IV. Requirements for Regional Haze Plans for 

the Second Implementation Period 

A. Identification of Class I Areas 

B. Calculations of Baseline, Current, and 

Natural Visibility Conditions; Progress to 

Date; and the Uniform Rate of Progress 

C. Long-Term Strategy for Regional Haze 

D. Reasonable Progress Goals 

E. Monitoring Strategy and Other State 

Implementation Plan Requirements 

F. Requirements for Periodic Reports 

Describing Progress Towards the 

Reasonable Progress Goals 

G. Requirements for State and Federal 

Land Manager Coordination 

V. The EPA’s Evaluation of Kansas’s Regional 

Haze Submission for the Second 

Implementation Period 

A. Background on Kansas’s First 

Implementation Period SIP Submission 

B. Kansas’s Second Implementation Period 

SIP Submission and the EPA’s 

Evaluation 

C. Identification of Class I Areas 

D. Regional Haze Rule Provisions That Do 

Not Apply to States With No Class I 

Areas 

E. Calculations of Baseline, Current, and 

Natural Visibility Conditions; Progress to 

Date; and the Uniform Rate of Progress 

F. Long-Term Strategy for Regional Haze 

a. Four-Factor Analysis 

b. Additional Long-Term Strategy 

Requirements 

G. Reasonable Progress Goals 

H. Monitoring Strategy and Other 

Implementation Plan Requirements 

I. Requirements for Periodic Reports 

Describing Progress Towards the 

Reasonable Progress Goals 

J. Requirements for State and Federal Land 

Manager Coordination 

VI. What action is the EPA taking? 

VII. Statutory and Executive Order Reviews 

I. Written Comments 

Submit your comments, identified by 

Docket ID No. EPA–R07–OAR–2023– 

0582, at https://www.regulations.gov. 

Once submitted, comments cannot be 

edited or removed from Regulations.gov. 

The EPA may publish any comment 

received to its public docket. Do not 

submit electronically any information 

you consider to be Confidential 

Business Information (CBI) or other 

information whose disclosure is 

restricted by statute. Multimedia 

submissions (audio, video, etc.) must be 

accompanied by a written comment. 

The written comment is considered the 

official comment and should include 

discussion of all points you wish to 

make. The EPA will generally not 

consider comments or comment 

contents located outside of the primary 

submission (i.e., on the web, cloud, or 

other file sharing system). For 

additional submission methods, the full 

EPA public comment policy, 

information about CBI or multimedia 

submissions, and general guidance on 

making effective comments, please visit 

https://www.epa.gov/dockets/ 

commenting-epa-dockets. 

II. What is being addressed in this 

document? 

The EPA is proposing to disapprove 

Kansas’s Regional Haze plan for the 

second planning period. As required by 

section 169A of the CAA, the federal 

RHR calls for state and federal agencies 

to work together to improve visibility in 

156 national parks and wilderness areas. 

The rule requires the states, in 

coordination with the EPA, the NPS, 

FWS, the FS, and other interested 

parties, to develop and implement air 

quality protection plans to reduce the 

pollution that causes visibility 

impairment in mandatory Class I 

Federal areas. Visibility impairing 

pollutants include fine and coarse 

particulate matter (PM) (e.g., sulfates, 

nitrates, organic carbon, elemental 

carbon, and soil dust) and their 

precursors (e.g., sulfur dioxide (SO2), 

oxides of nitrogen (NOX), and, in some 

cases, volatile organic compounds 

(VOC) and ammonia (NH3)). As 

discussed in further detail below, the 

EPA is proposing to find that Kansas has 

submitted a Regional Haze plan that 

does not meet the Regional Haze 

requirements for the second planning 

period. The State’s submission can be 

found in the docket for this action. 

III. 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 section 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 


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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. 

3There 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 (bext) is a metric used to for expressing 

visibility and is measured in inverse megameters 

(Mm–1). The EPA’s Guidance on Regional Haze 

State Implementation Plans for the Second 

Implementation Period (‘‘2019 Guidance’’) offers 

the flexibility for the use of light extinction in 

certain cases. Light extinction can be simpler to use 

in calculations than deciviews, since it is not a 

logarithmic function. See, e.g., 2019 Guidance at 16, 

19, https://www.epa.gov/visibility/guidanceregional-haze-state-implementation-plans-secondimplementation-period. The EPA Office of Air 

Quality Planning and Standards, Research Triangle 

Park (August 20, 2019). The formula for the 

deciview is 10 ln (bext)/10 Mm–1). 40 CFR 51.301. 

4The 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). 

6The 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, the EPA determined 

that natural visibility conditions would be reached 

in 60 years, or 2064 (60 years from the baseline 

starting point of 2004). However, the EPA did not 

establish 2064 as the year by which the national 

goal must be reached. 64 FR at 35731–32. 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). 

areas which impairment results from 

manmade air pollution.’’ CAA section 

169A(a)(1). The CAA further directs the 

EPA to promulgate regulations to assure 

reasonable progress toward meeting this 

national goal. CAA section 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 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. 

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 PM (e.g., sulfates, nitrates, 

organic carbon, elemental carbon, and 

soil dust) and their precursors (e.g., SO2, 

NOX, and, in some cases, VOC and 

NH3). Fine particle precursors react in 

the atmosphere to form fine PM (PM2.5), 

which impairs visibility by scattering 

and absorbing light. Visibility 

impairment reduces the perception of 

clarity and color, as well as visible 

distance.3

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 section 169A(b)(2); 4 see also 40 

CFR 51.308(b), (f) (establishing 

submission dates for iterative Regional 

Haze SIP revisions); (64 FR at 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 section 

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 section 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 LTS 

originally due July 31, 2018, and every 

ten years thereafter. (64 FR at 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 Id. at 35721. 

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 LTS 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’ LTS. 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 section 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’ 

LTS 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 


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7The 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 RooseveltCampobello International Park, the Chairman of the 

Roosevelt-Campobello International Park 

Commission.’’ 40 CFR 51.301. 

8 Guidance on Regional Haze State 

Implementation Plans for the Second 

Implementation Period. https://www.epa.gov/ 

visibility/guidance-regional-haze-stateimplementation-plans-second-implementationperiod The EPA Office of Air Quality Planning and 

Standards, Research Triangle Park (August 20, 

2019). 

9Clarifications Regarding Regional Haze State 

Implementation Plans for the Second 

Implementation Period. https://www.epa.gov/ 

system/files/documents/2021-07/clarificationsregarding-regional-haze-state-implementationplans-for-the-second-implementation-period.pdf. 

The EPA Office of Air Quality Planning and 

Standards, Research Triangle Park (July 8, 2021). 

10Technical Guidance on Tracking Visibility 

Progress for the Second Implementation Period of 

the Regional Haze Program. https://www.epa.gov/ 

visibility/technical-guidance-tracking-visibilityprogress-second-implementation-period-regional 

The EPA Office of Air Quality Planning and 

Standards, Research Triangle Park. (December 20, 

2018). 

11Recommendation 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-datausage-and-completeness-regional-haze-program. 

The EPA Office of Air Quality Planning and 

Standards, Research Triangle Park (June 3, 2020). 

12See, 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’’). 

13RPOs are sometimes also referred to as ‘‘multijurisdictional organizations,’’ or MJOs. For the 

purposes of this document, the terms RPO and MJO 

are synonymous. 

establishing their LTS, 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 

LTS, 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 

section 169A(d) and 40 CFR 51.308(i). 

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 

LTS 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 LTS, 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

As previously explained in the 2021 

Clarifications Memo, the 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 generally 

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 (NAAQS) and 

Prevention of Significant Deterioration 

(PSD) programs, as further emission 

reductions may be necessary to 

adequately protect visibility in Class I 

Areas throughout the country.12

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 


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14The 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). 

15The 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. 

emissions from State and Tribal land 

impact Class I Areas across the country, 

pursue the development of regional 

strategies to reduce emissions of PM and 

other pollutants leading to Regional 

Haze, and help states meet the 

consultation requirements of the RHR. 

The Central Regional Air Planning 

Association (CenRAP), one of the five 

RPOs described above, that Kansas was 

a member of during the first planning 

period, was a collaborative effort of state 

governments, tribal governments, and 

Federal Agencies established to initiate 

and coordinate activities associated 

with the management of Regional Haze, 

visibility, and other air quality issues in 

parts of the Great Plains, Midwest, 

Southwest, and South Regions of the 

United States. 

After the first planning period SIPs 

were submitted, the planning was 

shifted to the Central State Air 

Resources Agencies (CenSARA). 

CenSARA is a collaborative effort of 

state governments established to initiate 

and coordinate activities associated 

with the management of Regional Haze 

and other air quality issues in parts of 

the Great Plains, Midwest, Southwest, 

and South Regions of the United States. 

Member states include: Arkansas, Iowa, 

Kansas, Louisiana, Missouri, Nebraska, 

Oklahoma, and Texas. Unlike CenRAP, 

CenSARA has solely state members. 

However, CenSARA does reach out to 

Tribal and Federal partners. The Federal 

partners of CenSARA are the EPA, the 

NPS, the FWS, and FS. 

IV. 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 LTS 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 section 

169A(b)(2)(B). To this end, § 51.308(f) 

lays out the process by which states 

determine what constitutes their LTS, 

with the order of the requirements in 

§ 51.308(f)(1) through (f)(3) generally 

mirroring the order of the steps in the 

reasonable progress analysis 14 and (f)(4) 

through (f)(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 LTS. 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 LTS 

that includes the enforceable emission 

limitations, compliance schedules, and 

other measures that are necessary to 

make reasonable progress in such Areas. 

A reasonable progress determination is 

based on applying the four factors in 

CAA section 169A(g)(1) to sources of 

visibility-impairing pollutants that the 

state has selected to assess for controls 

for the second implementation period. 

Additionally, as further explained 

below, the RHR at 40 CFR 

51.3108(f)(2)(iv) separately provides five 

‘‘additional factors’’ 15 that states must 

consider in developing their LTS. 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 LTS. 

After a state has developed its LTS, it 

then establishes RPGs for each Class I 

Area within its borders by modeling the 

visibility impacts of all reasonable 

progress controls at the end of the 

second implementation period, i.e., in 

2028, as well as the impacts of other 

requirements of the CAA. The RPGs 

include reasonable progress controls not 

only for sources in the state in which 

the Class I Area is located, but also for 

sources in other states that contribute to 

visibility impairment in that Area. The 

RPGs are then compared to the baseline 

visibility conditions and the URP to 

ensure that progress is being made 

towards the statutory goal of preventing 

any future and remedying any existing 

anthropogenic visibility impairment in 

Class I Areas. 40 CFR 51.308(f)(2)–(3). 

In addition to satisfying the 

requirements at 40 CFR 51.308(f) related 

to reasonable progress, the Regional 

Haze SIP revisions for the second 

implementation period must address the 

requirements in § 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 

169(b)(2); CAA 110(a). Upon EPA 

approval, a SIP is enforceable by the 

Agency and the public under the CAA. 

If the EPA finds that a state fails to make 

a required SIP revision, or if the EPA 

finds that a state’s SIP is incomplete or 

if disapproves the SIP, the Agency must 

promulgate a federal implementation 

plan (FIP) that satisfies the applicable 

requirements. CAA 110(c)(1). 

A. Identification of Class I Areas 

The first step in developing a 

Regional Haze SIP is for a state to 

determine which Class I Areas, in 

addition to those within its borders, 

‘‘may be affected’’ by emissions from 

within the state. In the 1999 RHR, the 

EPA determined that all states 

contribute to visibility impairment in at 

least one Class I Area, 64 FR at 35720– 

22, 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. 

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.’’ 


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16The 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. 

17This document also refers to the 20% clearest 

and 20% most anthropogenically impaired days as 

the ‘‘clearest’’ and ‘‘most impaired’’ or ‘‘most 

anthropogenically impaired’’ days, respectively. 

18The 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 says 

‘‘most impaired days or the clearest days’’ where it 

should say ‘‘most impaired days and clearest days.’’ 

This is an error that was intended to be corrected 

in the 2017 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.’’ 

19Being 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 at 3093. 

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 § 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 

§ 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 3103–05. 

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. 

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. 

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 

§ 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 LTS 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 LTS 

‘‘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 based on 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. 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 LTS in its 

SIP. 40 CFR 51.308(f)(2). 

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 the EPA previously explained, 

consistent with the first implementation 

period, the EPA generally expects that 

each state will analyze at least SO2 and 

NOX 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 


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20Similarly, in responding to comments on the 

2017 RHR Revisions the 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. 

21The CAA provides that, ‘‘[i]n determining 

reasonable progress there shall be taken into 

consideration’’ the four statutory factors. CAA 

section 169A(g)(1). However, in addition to fourfactor 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 fourfactor analysis for the second planning period. 

22 ‘‘Each source’’ or ‘‘particular source’’ is used 

here as shorthand. While a source-specific analysis 

is one way of applying the four factors, neither the 

statute nor the RHR requires states to evaluate 

individual sources. Rather, states have ‘‘the 

flexibility to conduct four-factor analyses for 

specific sources, groups of sources or even entire 

source categories, depending on state policy 

preferences and the specific circumstances of each 

state.’’ 82 FR at 3088. 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. 

23See, 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, 

Continued 

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. 

The EPA explained in the 2021 

Clarifications Memo that each state has 

an obligation to submit a LTS 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 4.20 Additionally, as stated in both 

the 2019 Guidance and 2021 

Clarifications memo, a state that brings 

no sources forward for analysis of 

control measures must explain how 

doing so is consistent with the statutory 

and regulatory requirements for SIPs to 

contain the measures necessary to make 

reasonable progress. 2019 Guidance at 

10 and 2021 Clarifications Memo at 5– 

6. 

Thus, while states have discretion to 

choose any source selection 

methodology that is reasonable, 

whatever choices they make should be 

reasonably explained. To this end, 40 

CFR 51.308(f)(2)(i) requires that a state’s 

SIP submission include ‘‘a description 

of the criteria it used to determine 

which sources or groups of sources it 

evaluated.’’ The technical basis for 

source selection, which may include 

methods for quantifying potential 

visibility impacts such as emissions 

divided by distance metrics, trajectory 

analyses, residence time analyses, and/ 

or photochemical modeling, must also 

be appropriately documented, as 

required by 40 CFR 51.308(f)(2)(iii). 

Once a state has selected the set of 

sources, the next step is to determine 

the emissions reduction measures for 

those sources that are necessary to make 

reasonable progress for the second 

implementation period.21 This is 

accomplished by considering the four 

factors—‘‘the costs of compliance, the 

time necessary for compliance, and the 

energy and nonair quality 

environmental impacts of compliance, 

and the remaining useful life of any 

existing source subject to such 

requirements.’’ CAA section 169A(g)(1). 

The EPA has explained that the fourfactor 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 at 3091. Thus, for each 

source it has selected for four-factor 

analysis,22 a state must consider a 

‘‘meaningful set’’ of technically feasible 

control options for reducing emissions 

of visibility impairing pollutants. 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. 

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), the EPA explained that states 

should generally analyze efficiency 

improvements for sources’ existing 

measures as control options in their 

four-factor analyses, as in many cases 

such improvements are reasonable given 

that they typically involve only 

additional operation and maintenance 

costs. Additionally, the 2021 

Clarifications Memo provides that states 

that have assumed a higher emission 

rate than a source has achieved or could 

potentially achieve using its existing 

measures should also consider lower 

emission rates as potential control 

options. That is, a state should consider 

a source’s recent actual and projected 

emission rates to determine if it could 

reasonably attain lower emission rates 

with its existing measures. If so, the 

state should analyze the lower emission 

rate as a control option for reducing 

emissions. 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 additional factor alongside the four 

statutory factors.23 The 2019 Guidance 


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U.S. Environmental Protection Agency at 186; 2019 

Guidance at 36–37. 

24States may choose to, but are not required to, 

include measures in their LTS beyond just the 

emission reduction measures that are necessary for 

reasonable progress. See 2021 Clarifications Memo 

at 16. For example, states with smoke management 

programs may choose to submit their smoke 

management plans to the EPA for inclusion in their 

SIPs but are not required to do so. See, e.g., 82 FR 

at 3108–09 (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). 

25See 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). 

26The 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. 

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, the 

EPA explained that while visibility can 

reasonably be used when comparing 

and choosing between multiple 

reasonable control options, it should not 

be used to summarily reject controls 

that are reasonable given the four 

statutory factors. 2021 Clarifications 

Memo at 13. Ultimately, while states 

have discretion to reasonably weigh the 

factors and to determine what level of 

control is needed, § 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.’’ 

As explained above, § 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 § 51.308(f)(2), measures that 

are necessary to make reasonable 

progress towards the national visibility 

goal must be included in a state’s LTS 

and in its SIP.24 If the outcome of a fourfactor 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 section 

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 LTS 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 LTS or its SIP. 

As with source selection, the 

characterization of information on each 

of the factors is also subject to the 

documentation requirement in 

§ 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, § 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.25 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. 

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 LTS for making 

reasonable progress. Additionally, the 

RHR at 40 CFR 51.3108(f)(2)(iv) 

separately provides five ‘‘additional 

factors’’ 26 that states must consider in 

developing their LTS: (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 LTS. 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. The 

EPA provided further guidance on the 

five additional factors in the 2021 

Clarifications Memo, explaining that a 

state should generally not reject costeffective and otherwise reasonable 

controls merely because there have been 

emission reductions since the first 


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27RPGs are intended to reflect the projected 

impacts of the measures all contributing states 

include in their LTS. 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 LTS 

on disparate schedules, as well as for adjusting 

RPGs using a post-modeling approach. 2019 

Guidance at 47–48. 

planning period owing to other ongoing 

air pollution control programs or merely 

because visibility is otherwise projected 

to improve at Class I Areas. 

Additionally, states generally should 

not rely on these additional factors to 

summarily assert that the state has 

already made sufficient progress and, 

therefore, no sources need to be selected 

or no new controls are needed 

regardless of the outcome of four-factor 

analyses. 2021 Clarifications Memo at 

13. 

Because the air pollution that causes 

Regional Haze crosses state boundaries, 

§ 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 fourfactor analysis.’’ 82 FR at 3091. Their 

primary purpose is to assist the public 

and the EPA in assessing the 

reasonableness of states’ LTS for making 

reasonable progress towards the 

national visibility goal. See 40 CFR 

51.308(f)(3)(iii)–(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 LTS for the 

second implementation period.27 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’ 

LTS (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. 

For the second implementation 

period, the RPGs are set for 2028. RPGs 

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, § 51.308(f)(3)(i) 

requires that ‘‘[t]he long-term strategy 

and the RPG 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 LTS 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 at 3097–98. 

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 LTS. 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-thebooks and/or on-the-way control 

measures (i.e., control measures already 

required or anticipated before the fourfactor 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 


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28See ‘‘Step 8: Additional requirements for 

regional haze SIPs’’ in 2019 Regional Haze 

Guidance at 55. 

29 Id. 

30The 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. 

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 at 

3093, 3099–3100; 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). 

Section 51.308(f)(6)(v) further requires 

that all states’ SIPs provide for a 

statewide inventory of emissions of 

pollutants that are reasonably 

anticipated to cause or contribute to 

visibility impairment in any Class I 

Area; the inventory must include 

emissions for the most recent year for 

which data are available and estimates 

of future projected emissions. States 

must also include commitments to 

update their inventories periodically. 

The inventories themselves do not need 

to be included as elements in the SIP 

and are not subject to the EPA review 

as part of the Agency’s evaluation of a 

SIP revision.28 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.29

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 

§ 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.’’ 30 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. 

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 LTS and 

whether such implementation is in fact 

resulting in the expected visibility 

improvement. See 81 FR 26942, 26950 

(May 4, 2016), (82 FR at 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 LTS, 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, § 51.308(g)(3) requires states 

with Class I Areas within their borders 

to first determine current visibility 

conditions for each Area on the most 

impaired and clearest days, 40 CFR 

51.308(g)(3)(i)(B), and then to calculate 

the difference between those current 

conditions and baseline (2000–2004) 

visibility conditions in order to assess 

progress made to date. See 40 CFR 

51.308(g)(3)(ii)(B). 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)(B), 

(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 LTS for 

the first implementation period. 

G. Requirements for State and Federal 

Land Manager Coordination 

CAA section 169A(d) requires that 

before a state holds a public hearing on 

a proposed Regional Haze SIP revision, 

it must consult with the appropriate 


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31The 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 Columba may reasonably be 

anticipated to cause or contribute to visibility 

impairment in a Class I Area.’’ 64 FR at 35721. 

Hawaii, Alaska, and the U.S. Virgin Islands must 

also submit Regional Haze SIPs because they 

contain Class I Areas. 

32 ‘‘Related Class I Areas’’ is not a term used by 

the EPA, nor is it in CAA, the RHR, or any EPA 

guidance. Kansas coined the term in their 

submission. 

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). 

V. The EPA’s Evaluation of Kansas’s 

Regional Haze Submission for the 

Second Implementation Period 

A. Background on Kansas’s First 

Implementation Period SIP Submission 

Kansas submitted its Regional Haze 

SIP for the first implementation period 

to the EPA on October 26, 2009. The 

EPA approved Kansas’s first 

implementation period Regional Haze 

SIP submission on December 27, 2011 

(76 FR 80754, December 27, 2011). The 

requirements for Regional Haze SIPs for 

the first implementation period are 

contained in 40 CFR 51.308(d) and (e). 

Pursuant to 40 CFR 51.308(g), Kansas 

was also responsible for submitting a 

five-year progress report as a SIP 

revision for the first implementation 

period, which it did on March 10, 2015. 

The EPA approved the progress report 

into Kansas’s SIP on September 14, 2015 

(80 FR 55030, September 14, 2015). 

B. Kansas’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),51.308(g), and 51.308(i), on 

July 28, 2021, Kansas submitted a 

revision to Kansas’s SIP to address its 

Regional Haze obligations for the second 

implementation period, which runs 

through 2028. Kansas made its 2021 

Regional Haze SIP submission available 

for public comment on May 27, 2021. 

Kansas received and responded to 

public comments and included both the 

comments and responses to those 

comments in its submission. 

The following sections describe 

Kansas’s SIP submission. This 

document also contains EPA’s 

evaluation to determine if Kansas’s 

submission meets all of the applicable 

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 implements this statutory 

requirement at 40 CFR 51.308(f), which 

provides that each state’s plan ‘‘must 

address Regional Haze in each 

mandatory Class I Federal Area located 

within the State and in each mandatory 

Class I Federal Area located outside the 

State that may be affected by emissions 

from within the State,’’ and (f)(2), which 

requires each state’s plan to include a 

LTS 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 at 35721. In 

concluding that each of the contiguous 

48 states and the District of Columbia 

meet this threshold,31 the EPA relied on 

‘‘a large body of evidence 

demonstrat[ing] 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 at 

3094. 

Kansas contains no Class I Areas. 

However, in Kansas’s Regional Haze 

plan, Kansas lists seven Class I Areas: 

Upper Buffalo Wilderness Area, 

Arkansas; Hercules-Glades Wilderness 

Area, Missouri; Mingo Wilderness Area, 

Missouri; Salt Creek Wilderness Area, 

New Mexico; Wheeler Peak Wilderness 

Area, New Mexico; White Mountain 

Wilderness Area, New Mexico; and 

Wichita Mountains Wilderness Area, 

Oklahoma; as ‘‘Kansas-related Class I 

Areas, 32 i.e., Class I Areas potentially 

affected by Kansas emissions. To make 

this determination, Kansas used the 

results from the CenSARA 2018 area of 

influence (AOI) analysis. The AOI 

analysis is a back-trajectory technique 

that identifies visibility impairment 

contributions from individual major 

point sources. The EPA agrees that the 

CenSARA AOI information is a 


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33Based upon the CenSARA AOI work. See the 

July 28th, 2021 Kansas submission, Appendix 6, 

included in the docket for this action. 

34AOI is one of several methods to estimate the 

visibility impact of sources. Different methods 

could have different rankings. AOI is an acceptable 

method. 

35The EPA is not determining that these four 

sources would need to be selected. The EPA is 

highlighting that visibility impacting sources exist 

to be selected. Kansas could also have a reasonable 

technically sound method for 

identifying Areas that are potentially 

affected by Kansas emissions. The EPA 

also agrees that the seven Class I Areas 

identified by Kansas are potentially 

affected by Kansas’s emissions. 

In their second planning period 

submission, Kansas also opted to 

analyze the visibility impacts from 

Kansas, and compare those to visibility 

impacts from other states also impacting 

the same seven Class I Areas. That 

analysis showed seventeen states having 

more visibility impact on the seven 

Class I Areas compared to Kansas. 

Kansas additionally states that its 

emissions have an insignificant 

visibility impact in the seven Class I 

Areas it identified. The EPA notes that 

while Kansas’s analysis shows it has 

less of a visibility impact than other 

states in the seven Class I Areas it 

identified, Kansas also showed that its 

sources do, in fact, impact visibility in 

these seven Class I Areas. As stated 

previously, the threshold for visibility 

impact on Class I Areas is low. 

Therefore, a small visibility impact on 

any of the Class I Areas identified by 

Kansas as being impacted by its 

emissions is sufficient to trigger the 

regional haze requirements to evaluate 

sources for control measures 

considering the four factors. 

D. Regional Haze Rule Provisions That 

Do Not Apply to States With No Class 

I Areas 

As noted above, Kansas emissions 

potentially impact visibility in seven 

out-of-state Class I Areas. However, 

Kansas does not contain any Class I 

Areas. Therefore, a number of RHR 

provisions are not applicable to the 

Kansas SIP submission and the EPA will 

not evaluate the Kansas regional haze 

SIP submission for compliance with 

those provisions. 

The following RHR provisions do not 

apply to the Kansas SIP: 

• § 51.308(f)(1)—Calculations of 

baseline, current, and natural visibility 

conditions; progress to date; and the 

uniform rate of progress. The entirety of 

the provisions in § 51.308(f)(1), 

including 51.308(f)(i) to 51.308(f)(vi) 

only contain regulatory requirements for 

states with Class I Areas. 

• § 51.308(f)(3)—Reasonable progress 

goals. § 51.308(f)(3)(i), 

51.308(f)(3)(ii)(A), 51.308(f)(3)(iii), and 

51.308(f)(3)(iv) only contain regulatory 

requirements for states with Class I 

Areas. 

• § 51.308(f)(4)—Additional 

monitoring to assess reasonably 

attributable visibility impairment 

(RAVI). This provision could in theory 

apply to all states. However, there are 

no RAVI monitoring requirements for 

Kansas. Therefore, this provision is not 

applicable to the Kansas SIP. 

• § 51.308(f)(6)—Monitoring strategy 

and other implementation plan 

requirements. § 51.308(f)(6), 

51.308(f)(6)(i), 51.308(f)(6)(ii), and 

51.308(f)(6)(iv) only contain regulatory 

requirements for states with Class I 

Areas. 

• § 51.308(g)—Requirements for 

periodic reports describing progress 

towards the reasonable progress goals. 

The RHR at § 51.308(f)(5) requires 

second planning period SIPs to address 

certain progress report provisions 

within § 51.308(g). However, 

§ 51.308(g)(3) only contains regulatory 

requirements for states with Class I 

Areas. 

E. Calculations of Baseline, Current, and 

Natural Visibility Conditions; Progress 

to Date; and the Uniform Rate of 

Progress 

Section 51.308(f)(1) requires states to 

determine the following for ‘‘each 

mandatory Class I Federal Area located 

within the State’’: baseline visibility 

conditions for the most impaired and 

clearest days, natural visibility 

conditions for the most impaired and 

clearest days, progress to date for the 

most impaired and clearest days, the 

differences between current visibility 

conditions and natural visibility 

conditions, and the URP. This section 

also provides the option for states to 

propose adjustments to the URP line for 

a Class I Area to account for visibility 

impacts from anthropogenic sources 

outside the United States and/or the 

impacts from wildland prescribed fires 

that were conducted for certain, 

specified objectives. 40 CFR 

51.308(f)(1)(vi)(B). 

These requirements only apply to 

states with Class I Areas. Because 

Kansas does not have any Class I Areas, 

these statutory requirements do not 

apply to Kansas. 

F. Long-Term Strategy for Regional Haze 

a. Four-Factor Analysis 

Each state having a Class I Area 

within its borders or emissions that may 

affect visibility in a Class I Area must 

develop a LTS for making reasonable 

progress towards the national visibility 

goal. CAA section 169A(b)(2)(B). As 

explained in the Background section of 

this document, 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 LTS 

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 fourfactor analyses are necessary to make 

reasonable progress and must be in the 

LTS. If the outcome of a four-factor 

analysis and other measures necessary 

to make reasonable progress is that no 

new measures are reasonable for a 

source, that source’s existing measures 

are necessary to make reasonable 

progress, unless the state can 

demonstrate that the source will 

continue to implement those measures 

and will not increase its emission rate. 

Existing measures that are necessary to 

make reasonable progress must also be 

in the LTS. In developing its LTS, a 

state must also consider the five 

additional factors in § 51.308(f)(2)(iv). 

As part of its reasonable progress 

determinations, the state must describe 

the criteria used to determine which 

sources or group of sources were 

evaluated (i.e., subjected to four-factor 

analysis) for the second implementation 

period and how the four factors were 

taken into consideration in selecting the 

emission reduction measures for 

inclusion in the LTS. 40 CFR 

51.308(f)(2)(iii). 

In its SIP submission, Kansas 

included information on the emissions 

impacts of numerous sources in Kansas 

on various Class I Areas, but did not 

select any sources, did not conduct any 

four-factor analysis, and did not analyze 

possible efficiency improvements for 

sources’ existing measures. However, 

Kansas’s own submission lists one 

hundred twenty-eight (128) sources in 

Kansas with non-zero visibility impacts 

on at least one Class I Area, and when 

SO2 and NOX emissions were 

considered together, impacts from 

individual Kansas sources ranged from 

0.01% to 0.84% of the total estimated 

visibility impact.33 The highest 

impacting sources based on the AOI 

metric used by Kansas 34 are Sunflower 

Electric-Holcomb, KCP&L–La Cygne, 

Birla Carbon USA, Kansas City BPU– 

Nearman.35


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basis to select a different, smaller, or larger set of 

sources. 36Based upon the CenSARA AOI work. See the 

July 28th, 2021 Kansas submission, Appendix 6, 

included in the docket for this action. For Hercules 

Glades Wilderness Area, Missouri: Arkansas and 

Missouri each have greater than twenty-five percent 

impact; Oklahoma, Illinois, Texas, and Kentucky 

each have between ten and four percent impact; and 

Iowa, Kansas, Tennesse, Louisiana, and Nebraska 

each have between three and one percent impact. 

37Responses to Comments on Protection of 

Visibility: Amendments to Requirements for States 

Plans; Proposed Rule (81 FR 26942, May 4, 2016) 

at 87–88, available at https://www.regulations.gov/ 

document/EPA-HQ-OAR-2015-0531-0635. 

38 2021 Clarifications Memo at 4. 

39 Id. 

40 2021 Clarifications Memo at 13. 

41 2021 Clarifications Memo at 15. 

42See June 28, 2021 letter from Dana Skelley, 

Director Air and Radiation Division, EPA Region 7 

to Douglas Watson Air Monitoring and Planning 

Section Chief, KDHE. The letter is titled ‘‘EPA 

Comments on KS 2nd Round RH SIP 

LETTERHEAD.pdf’’ in the docket for this action. 

43See CAA sections 169A(b)(2)(B), 169A(g)(1). 

44 Guidance on Regional Haze State 

Implementation Plans for the Second 

Implementation Period, at 10. https://www.epa.gov/ 

visibility/guidance-regional-haze-stateimplementation-plans-second-implementationperiod. The EPA Office of Air Quality Planning and 

Standards, Research Triangle Park (August 20, 

2019). 

In its SIP submission, Kansas 

provides several reasons why it believes 

it is reasonable to not select sources for 

four-factor analyses, none of which are 

based in statute or the Regional Haze 

regulations. For example, Kansas 

believes there is an ‘‘emission control 

inequity’’ between Kansas and 

surrounding states. Therefore, Kansas 

suggests it is unfair to require the state 

to select sources and conduct four-factor 

analyses in order to determine if 

existing limits and/or controls are 

sufficient, or if additional controls are 

needed for reasonable progress. Kansas 

believes that surrounding states should 

first match Kansas’s emission 

reductions before Kansas is required to 

consider further controls. However, 

there is ample information presented by 

the state to show that sources in Kansas 

do impact nearby Class I Areas and the 

state could have selected the visibility 

impairing sources in Kansas for further 

analysis. This fact remains true 

regardless of whether a neighboring 

state contributes more. Neither the 

statute nor the RHR contemplate 

‘‘emission control inequity’’ as a 

justification for a state not to select 

sources and evaluate existing and 

potential control measures, considering 

the four statutory factors. 

As stated above, impacts from 

individual Kansas’s sources ranged from 

0.01% to 0.84% of the total estimated 

impact.36 Moreover, the 2017 RHR 

recognized the possibility that smaller 

in-state sources may need to be selected 

and evaluated for control measures as a 

part of the reasonable progress analysis 

in order to address the state’s visibility 

impact to Class I Areas. This was further 

clarified in the 2021 Clarifications 

memo where the EPA stated 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.’’ 37 States should not use large 

out-of-state sources to exclude 

contributions from relatively smaller but 

still important in-state sources.38 States 

with relatively small sources compared 

to their neighbors should nonetheless 

select their largest in-state sources.39

Therefore, despite the fact that 

surrounding states contribute a larger 

percentage of visibility impairment to a 

specific Class I Area compared to 

Kansas, that does not mean that 

Kansas’s contributions to visibility 

impairment are insignificant. On the 

contrary, the fact that Kansas 

contributes to visibility impacts to Class 

I Areas, even at the levels that it does, 

is evidence that sources in Kansas 

should be evaluated, including 

consideration of the four factors, to 

determine whether cost effective 

controls for those sources exist and to 

determine measures that are necessary 

to make reasonable progress. 

Further, the national goal set by 

Congress outlines both the remedying of 

any existing visibility impairment, and 

also preventing any future visibility 

impairment. CAA section 169A(a). In 

addition to not selecting sources for a 

four-factor analysis, Kansas also did not 

evaluate whether the continued 

implementation of a source’s existing 

measures is necessary for reasonable 

progress. Kansas therefore did not 

provide a reasonable rationale to 

support its conclusion that for the 

second planning period, no additional 

measures are necessary for its LTS, 

despite outlining seven Class I Areas 

where its emissions impact visibility. 

Kansas also argues that because of the 

SO2 reductions it has achieved in the 

first planning period compared to other 

states, Kansas’s contribution to 

impairment in Class I Areas is therefore 

insignificant. The EPA acknowledges 

that Kansas made significant reductions 

in SO2 emissions in the first planning 

period and that surrounding states have 

a larger total of SO2 emissions, but 

neither the Regional Haze Rule nor the 

CAA allow a state to not select sources, 

nor consider the four factors, in reliance 

on their previous planning period 

reductions or due to higher emissions in 

other states. This was further clarified in 

the 2021 Clarifications memo where the 

EPA stated 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.40

A source’s visibility impact relative to 

a state’s total contribution to visibility 

impairment is relevant to ensuring that 

a state is addressing its own 

contribution regardless of what other 

states are doing.41

Therefore, the EPA does not find it 

reasonable for Kansas to not select 

sources and evaluate potential control 

measures, without consider the four 

factors in the CAA and EPA’s 

regulations to determine what costeffective measures, if any, are necessary 

to make reasonable progress toward the 

national goal, and thus need to be a part 

of the state’s LTS. 

Kansas failed to ‘‘evaluate and 

determine the emission reduction 

measures that are necessary to make 

reasonable progress by considering the 

costs of compliance, the time necessary 

for compliance, the energy and non-air 

quality environmental impacts of 

compliance, and the remaining useful 

life of any potentially affected 

anthropogenic source of visibility 

impairment,’’ as required by 40 CFR 

51.308(f)(2)(i) and CAA section 

169A(g)(1). The EPA outlined this fact 

during the public comment period of 

Kansas’s draft SIP submittal.42 In 

Kansas’s response to our comments, it 

declaratively states it cannot consider 

the four factors without selecting 

sources. Providing a long-term strategy 

for making reasonable progress toward 

the national goal, including 

consideration of the four factors, is a 

statutory requirement for every state, 

one that does not go away by a state 

simply deciding, without analyses, that 

doing so would lead to insignificant 

results.43 The EPA discusses a state not 

selecting sources in both the 2019 

Guidance and the 2021 Clarification 

Memo. As the EPA stated in the 2019 

Guidance, a state must explain how the 

decision to bring forth no sources is 

consistent with the CAA’s requirements 

that SIPs make reasonable progress 

toward the national goal of preventing 

future and remedying existing 

anthropogenic visibility impairment, 

and that reasonable progress must be 

determined by considering the four 

statutory factors.44 EPA then provides 


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45 Id. 

46Clarifications Regarding Regional Haze State 

Implementation Plans for the Second 

Implementation Period at 5 and 6. https://

www.epa.gov/system/files/documents/2021-07/ 

clarifications-regarding-regional-haze-stateimplementation-plans-for-the-secondimplementation-period.pdf. The EPA Office of Air 

Quality Planning and Standards, Research Triangle 

Park (July 8, 2021). 

47See 40 CFR 51.308(f)(2). 

48See the July 28th, 2021 Kansas submission, 

Appendix 9, included in the docket for this action. 

49 Kansas did not have emission inventories for 

2015 and 2018 and instead estimated emissions 

using a statistical method, the ‘‘least squares’’ 

method. Kansas does not explain in its submission 

why it is missing data from 2015 and 2018. 

an example of how a state could make 

such a demonstration.45

The EPA further explained in the 

2021 Clarification Memo that a state that 

brings no sources forward for analysis of 

control measures must explain how 

doing so is consistent with the statutory 

and regulatory requirements for SIPs to 

contain the measures necessary to make 

reasonable progress. In this case, the 

state is not merely asserting that its 

sources need no further controls to 

make reasonable progress, but that even 

identifying sources to analyze is a futile 

exercise because it is obvious that a 

four-factor analysis would not result in 

any new controls.46 Kansas has not 

adequately supported this assertion. To 

reach a determination that existing 

measures are sufficient for Reasonable 

Progress, the four factors must be 

considered. Kansas has not provided a 

reasoned explanation for how not 

selecting sources and not considering 

the four factors, is consistent with the 

statute and the RHR. Further, Kansas 

has not shown that further reductions of 

visibility impairing pollutants are not 

reasonable, and has not explained how 

its approach, which fails to consider the 

four factors, is consistent with the CAA 

and RHR. The State is required to 

consider the four factors to determine 

what, if any, measures are necessary for 

reasonable progress and must be 

included in the state’s long-term 

strategy and regulatory portion of the 

SIP submission. For Kansas, given the 

state has numerous sources emitting 

visibility-impairing pollutants that may 

impact Class I Areas, the State’s 

approach is unsupportable. 

Kansas failed to consider the four 

statutory factors for any sources, thereby 

not providing the required analysis to 

support a conclusion that no additional 

measures are necessary for reasonable 

progress in its LTS. Therefore, Kansas 

does not establish that its second 

planning period SIP submission 

contains the emission limits, schedules 

of compliance, and other measures as 

may be necessary to make reasonable 

progress toward meeting the national 

visibility goal.47 Therefore, the SIP 

submission does not meet the regional 

haze requirements, nor requirements of 

the CAA. Specifically, as described in 

detail above, the SIP submission does 

not meet the statutory requirements in 

CAA section 169A(b)(2)(B) to contain a 

LTS for making reasonable progress; the 

CAA section 169A(g)(1) requirement to 

consider the four factors in determining 

reasonable progress; and the CAA 

section 169A(b)(2) requirement for the 

SIP to contain the emissions limits, 

schedules of compliance and other 

measures as may be necessary to make 

reasonable progress toward meeting the 

national goal. In addition, the lack of 

source selection, evaluation of 

emissions measures considering the four 

factors, and related inadequate 

documentation of the analyses results in 

not meeting the regulatory requirements 

in § 51.308(f)(2), 51.308(f)(2)(i), and 

51.308(f)(2)(iii). Therefore, the EPA is 

proposing to disapprove Kansas’s 

Regional Haze SIP submission. 

b. Additional Long-Term Strategy 

Requirements 

The consultation requirements of 

§ 51.308(f)(2)(ii) provides that states 

must consult with other states that are 

reasonably anticipated to contribute to 

visibility impairment in a Class I Area 

to develop coordinated emission 

management strategies containing the 

emission reductions measures that are 

necessary to make reasonable progress. 

Section 51.308(f)(2)(ii)(A) and (B) 

require states to consider the emission 

reduction measures identified by other 

states as necessary for reasonable 

progress and to include agreed upon 

measures in their SIPs, respectively. 

Section 51.308(f)(2)(ii)(C) speaks to 

what happens if states cannot agree on 

what measures are necessary to make 

reasonable progress. 

Kansas included documentation of its 

CenSARA calls that occurred from 

January 2020 to July 2020. Kansas 

contacted the states of Colorado and 

New Mexico in May 2020. Kansas’s 

consultation documentation is free of 

any state disagreeing with or providing 

comment on Kansas’s approach on its 

LTS. However, for the reasons outlined 

throughout this document, the EPA 

cannot approve Kansas’s consultation 

requirements because the consultation 

was based on a SIP that did not meet the 

required statutory elements. 

Section 51.308(f)(2)(iii) also requires 

that the emissions information 

considered to determine the measures 

that are necessary to make reasonable 

progress include information on 

emissions for the most recent year for 

which the state has submitted triennial 

emissions data to the EPA (or a more 

recent year), with a 12-month 

exemption period for newly submitted 

data. 

Kansas included emissions 

information from the most recent year in 

its submittal.48 Kansas included 

emission totals for NH3, PM2.5, PM10, 

SO2, VOC, and NOX. Kansas grouped 

the emissions by: Natural Sources, Wild 

and Prescribed Fires, Residential Wood 

Combustion, Agricultural Fires, 

Agricultural NH3 Emissions, the Oil and 

Gas Industry, Electric Generating Units 

(EGUs), Industry other than Oil and Gas 

and EGUs, Airports, Rail, Marine, 

Onroad, and Nonroad. Kansas included 

emissions 2011 through 2017. Kansas 

used the National Emissions Inventory 

for 2011, 2014, 2017; the EPA 2016 

modeling inventory for 2016; and the 

Kansas Emission Inventory for 2012, 

2013, and 2017.49

TABLE 1—KANSAS ANTHROPOGENIC NOX EMISSIONS

Section Pollutant 2014 2015 2016 2017 2018 

Oil and Gas .................................................... NOX ......... 62,100 57,172 49,832 52,141 46,008 

Other Industry ................................................ NOX ......... 47,617 45,064 41,759 41,460 38,531 

Onroad ........................................................... NOX ......... 73,361 64,648 54,097 50,897 41,264 

Rail ................................................................. NOX ......... 29,313 26,344 21,770 23,617 19,845 

EGU ............................................................... NOX ......... 26,681 18,030 15,231 13,378 14,455 

Nonroad ......................................................... NOX ......... 32,011 28,948 25,373 23,846 20,528 

Airports ........................................................... NOX ......... 1,740 1,764 1,811 1,764 1,799 

Ag Fire ........................................................... NOX ......... 2,531 1,717 593 709 709 

Residential Wood ........................................... NOX ......... 368 361 378 297 302 


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50See the July 28th, 2021 Kansas submission, 

Appendix 9, included in the docket for this action. 

TABLE 1—KANSAS ANTHROPOGENIC NOX EMISSIONS—Continued 

Section Pollutant 2014 2015 2016 2017 2018 

Marine ............................................................ NOX ......... 16 8 0 ........................ ........................

From July 28th, 2021 Kansas submission, Appendix 9. 

TABLE 2—KANSAS ANTHROPOGENIC SO2 EMISSIONS

Section Pollutant 2014 2015 2016 2017 2018 

Other Industry ................................................ SO2 .......... 7,352 6,904 6,381 6,157 5,671 

EGU ............................................................... SO2 .......... 31,541 13,858 7,137 5,558 5,450 

Airports ........................................................... SO2 .......... 176 182 192 186 194 

Onroad ........................................................... SO2 .......... 293 290 294 271 271 

Ag Fire ........................................................... SO2 .......... 660 433 123 145 145 

Residential Wood ........................................... SO2 .......... 107 102 107 68 68 

Oil and Gas .................................................... SO2 .......... 108 89 63 67 44 

Nonroad ......................................................... SO2 .......... 59 50 37 38 27 

Rail ................................................................. SO2 .......... 18 16 14 16 14 

From July 28th, 2021 Kansas submission, Appendix 9. 

As summarized above, the state 

provided emissions inventory 

information by sector and for individual 

sources for multiple years, including the 

most recent year for which the state 

submitted emissions data to the EPA in 

compliance with the triennial reporting 

requirements of the AERR. However, 

because the State did not conduct the 

proper analyses to determine what 

measures are necessary for reasonable 

progress, it is not clear how this 

emissions data was used in the 

submission to fulfill the regional haze 

requirements, including documentation 

of the technical basis for determining 

the emissions measures that are 

necessary for reasonable progress. 

Therefore, as outlined throughout this 

document, the EPA cannot approve the 

regulatory requirements under 

§ 51.308(f)(2)(iii) because Kansas’s SIP 

did not meet the required statutory 

elements. 

G. Reasonable Progress Goals 

Section 51.308(f)(3) contains the 

requirements pertaining to RPGs for 

each Class I Area. As noted previously, 

most of regulatory requirements in 

§ 51.308(f)(3) do not apply to states 

without Class I Areas. However, 

§ 51.308(f)(3)(ii)(B) requires that if a 

state contains sources that are 

reasonably anticipated to contribute to 

visibility impairment in a Class I Area 

in another state, and the RPG for the 

most impaired days in that Class I Area 

is above the URP, the upwind state must 

provide the same demonstration. 

At the time Kansas submitted its SIP, 

this provision did not apply because the 

states with Class I Areas that are 

affected by Kansas sources did not 

submit any RPGs that are above the 

respective URPs. Because we are 

disapproving the Kansas SIP, if Kansas 

chooses to submit a revised SIP to the 

EPA, it should re-evaluate whether 40 

CFR 51.308(f)(3)(ii)(B) applies to 

Kansas. 

H. Monitoring Strategy and Other 

Implementation Plan Requirements 

Section 51.308(f)(6) specifies that 

each comprehensive revision of a state’s 

Regional Haze SIP must contain or 

provide for certain elements, including 

monitoring strategies, emissions 

inventories, and any reporting, 

recordkeeping and other measures 

needed to assess and report on 

visibility. A main requirement of this 

subsection is for states with Class I 

Areas to submit monitoring strategies 

for measuring, characterizing, and 

reporting on visibility impairment. 

Section 51.308(f)(6)(ii) requires SIPs to 

provide for procedures by which 

monitoring data and other information 

are used in determining the contribution 

of emissions from within the state to 

Regional Haze visibility impairment at 

mandatory Class I Federal Areas both 

within and outside the state. As noted 

previously, most of regulatory 

requirements in § 51.308(f)(6) do not 

apply to states without Class I Areas. 

However, § 51.308(f)(6)(iii) and 

(f)(6)(v) apply to all states that have 

emissions that contribute to a Class I 

Area, including Kansas. Section 

51.308(f)(6)(iii) requires SIPs to provide 

procedures by which monitoring data 

and other information are used in 

determining the contribution of 

emissions from within the State to 

Regional Haze visibility impairment at 

mandatory Class I Federal Areas in 

other States. 

Section 51.308(f)(6)(v) requires SIPs to 

provide for a statewide inventory of 

emissions of pollutants that are 

reasonably anticipated to cause or 

contribute to visibility impairment, 

including emissions for the most recent 

year for which data are available and 

estimates of future projected emissions. 

It also requires a commitment to update 

the inventory periodically. Section 

51.308(f)(6)(v) also requires states to 

include estimates of future projected 

emissions and include a commitment to 

update the inventory periodically. 

Kansas generally included details on 

the emissions and monitoring data they 

used to estimate their visibility 

contribution to out-of-state Class I 

Areas, to address § 51.308(f)(6)(iii). To 

address § 51.308(f)(6)(v), Kansas 

included emissions information from 

the most recent triennial inventory year 

available (2017) 50. Kansas also included 

future projections for 2023 and 2028 

and committed to update the inventory 

periodically. 

However, as mentioned above, 

because the State did not conduct the 

proper analyses to determine what 

measures are necessary for reasonable 

progress, and did not satisfy the regional 

haze statutory requirements, the EPA is 

not approving these regulatory 

requirements at this time. The EPA is 

not approving these regulatory 

requirements because they do not 

contain measures that strengthen the 

existing regional haze SIP, or the SIP 

generally. 

I. Requirements for Periodic Reports 

Describing Progress Towards the 

Reasonable Progress Goals 

Section 51.308(f)(5) requires that 

periodic comprehensive revisions of 

states’ Regional Haze plans also address 


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the progress report requirements of 40 

CFR 51.308(g)(1) through (5). The 

purpose of these requirements is to 

evaluate progress towards the applicable 

RPGs for each Class I Area within the 

state and each Class I Area outside the 

state that may be affected by emissions 

from within that state. Sections 

51.308(g)(1) and (2) apply to all states 

and require a description of the status 

of implementation of all measures 

included in a state’s first 

implementation period Regional Haze 

plan and a summary of the emission 

reductions achieved through 

implementation of those measures. 

Section 51.308(g)(3) applies only to 

states with Class I Areas within their 

borders and requires such states to 

assess current visibility conditions, 

changes in visibility relative to baseline 

(2000–2004) visibility conditions, and 

changes in visibility conditions relative 

to the period addressed in the first 

implementation period progress report. 

Section 51.308(g)(4) applies to all 

states and requires an analysis tracking 

changes in emissions of pollutants 

contributing to visibility impairment 

from all sources and sectors since the 

period addressed by the first 

implementation period progress report. 

This provision further specifies the year 

or years through which the analysis 

must extend depending on the type of 

source and the platform through which 

its emission information is reported. 

Finally, § 51.308(g)(5), which also 

applies to all states, requires an 

assessment of any significant changes in 

anthropogenic emissions within or 

outside the state have occurred since the 

period addressed by the first 

implementation period progress report, 

including whether such changes were 

anticipated and whether they have 

limited or impeded expected progress 

towards reducing emissions and 

improving visibility. 

As noted previously, § 51.308(g)(3) 

does not apply to states without Class I 

Areas. With respect to the rest of the 

§ 51.308(g) requirements, Kansas 

included a description of the status of 

the implementation of all measures 

included in Kansas’s first 

implementation period Regional Haze 

Plan, a summary of the emissions 

reductions achieved from these 

measures, an analysis tracking changes 

in emissions, and an assessment of 

significant changes in emissions. 

However, as outlined throughout this 

document, because Kansas’s SIP 

submission did not meet the required 

statutory or regulatory requirements, the 

EPA is not approving these regulatory 

requirements at this time. The EPA is 

not approving these regulatory 

requirements because they do not 

contain measures that strengthen the 

regional haze SIP, or the SIP generally. 

J. Requirements for State and Federal 

Land Manager Coordination 

Section 169A(d) of the CAA requires 

states to consult with FLMs before 

holding the public hearing on a 

proposed Regional Haze SIP, and to 

include a summary of the FLMs’ 

conclusions and recommendations in 

the notice to the public.’’ 

Section 51.308(i)(2)’s FLM 

consultation provision requires a state 

to provide FLMs with an opportunity 

for consultation that is early enough in 

the state’s policy analyses of its 

emission reduction obligation so that 

information and recommendations 

provided by the FLMs’ can 

meaningfully inform the state’s 

decisions on its LTS. If the consultation 

has taken place at least 120 days before 

a public hearing or public comment 

period, the opportunity for consultation 

will be deemed early enough. 

Regardless, the opportunity for 

consultation must be provided at least 

sixty days before a public hearing or 

public comment period at the state 

level. Section 51.308(i)(2) also provides 

two substantive topics on which FLMs 

must be provided an opportunity to 

discuss with states: assessment of 

visibility impairment in any Class I Area 

and recommendations on the 

development and implementation of 

strategies to address visibility 

impairment. Section 51.308(i)(3) 

requires states, in developing their 

implementation plans, to include a 

description of how they addressed 

FLMs’ comments. 

Kansas included summaries of its 

consultation with various FLMs. On 

January 14, 2021, the NPS deferred 

consultation to other FLMs. In February 

and March of 2021, Kansas had a video 

call and email exchanges with the FS. 

Kansas included the comments from the 

FS and its responses. On February 19, 

2021, Kansas had a video call with the 

FWS. Kansas included the comments 

from FWS and its responses. While 

Kansas did take administrative steps to 

conduct consultation, if the EPA 

finalizes the disapproval of the SIP, in 

the process of correcting the 

deficiencies outlined above with respect 

to the RHR and statutory requirements, 

the state (or the EPA in the case of an 

eventual FIP) will be required to again 

satisfy the FLM consultation 

requirements under § 51.308(i)(2). 

Therefore, the EPA cannot approve 

Kansas’s consultation requirements 

because Kansas’s consultation was 

based on a SIP that did not meet the 

required statutory and regulatory 

requirements. 

VI. What action is the EPA taking? 

The EPA is proposing to disapprove 

the Kansas SIP submission relating to 

Regional Haze for the second planning 

period received on July 28, 2021, 

because the state’s SIP submission fails 

to meet both the regulatory 

requirements of the Regional Haze Rule 

and the statutory requirements of the 

Clean Air Act. Specifically, because 

Kansas failed to consider the four 

statutory factors, thereby not including 

a LTS that includes measures necessary 

for reasonable progress in its second 

planning period SIP submission, 

Kansas’s SIP submission does not 

contain the emission limits, schedules 

of compliance, and other measures as 

may be necessary to make reasonable 

progress toward meeting the national 

visibility goal. Therefore, the SIP 

submission does not meet the regional 

haze requirements, nor requirements of 

the CAA. Specifically, as described in 

detail above, the SIP submission does 

not meet the statutory requirements in 

CAA section 169A(b)(2)(B) to contain a 

LTS for making reasonable progress; the 

CAA section 169A(g)(1) requirement to 

consider the four factors in determining 

reasonable progress; and the CAA 

section 169A(b)(2) requirement for the 

SIP to contain the emissions limits, 

schedules of compliance and other 

measures as may be necessary to make 

reasonable progress toward meeting the 

national goal. In addition, the lack of 

source selection, evaluation of 

emissions measures considering the four 

factors, and related inadequate 

documentation results in the Kansas 

submission not meeting the regulatory 

requirements in § 51.308(f)(2), 

51.308(f)(2)(i), and 51.308(f)(2)(iii). 

The EPA is not proposing a FIP at this 

time. If the EPA finalizes the 

disapproval, that will start a two-year 

clock for the EPA to propose and 

finalize a FIP. We are processing this as 

a proposed action because we are 

soliciting comments on this proposed 

action. Disapproval does not start a 

mandatory sanctions clock for Kansas. 

Final rulemaking will occur after 

consideration of any comments. 

VII. Statutory and Executive Order 

Reviews 

Under the CAA, the Administrator is 

required to approve a SIP submission 

that complies with the provisions of the 

Act and applicable Federal regulations. 

42 U.S.C. 7410(k); 40 CFR 52.02(a). 

Thus, in reviewing SIP submissions, the 

EPA’s role is to approve state choices, 

provided that they meet the criteria of 


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the CAA. This action proposes to 

disapprove the state submittal as not 

meeting Federal requirements and does 

not impose additional requirements. For 

that reason, this action: 

• Is not a significant regulatory action 

subject to review by the Office of 

Management and Budget under 

Executive Orders 12866 (58 FR 51735, 

October 4, 1993) and 13563 (76 FR 3821, 

January 21, 2011); 

• Does not impose an information 

collection burden under the provisions 

of the Paperwork Reduction Act (44 

U.S.C. 3501 et seq.); 

• Is certified as not having a 

significant economic impact on a 

substantial number of small entities 

under the Regulatory Flexibility Act (5 

U.S.C. 601 et seq.); 

• Does not contain any unfunded 

mandate or significantly or uniquely 

affect small governments, as described 

in the Unfunded Mandates Reform Act 

of 1995 (Pub. L. 104–4); 

• Does not have federalism 

implications as specified in Executive 

Order 13132 (64 FR 43255, August 10, 

1999); 

• Is not an economically significant 

regulatory action based on health or 

safety risks subject to Executive Order 

13045 (62 FR 19885, April 23, 1997); 

• Is not a significant regulatory action 

subject to Executive Order 13211 (66 FR 

28355, May 22, 2001); 

• Is not subject to requirements of the 

National Technology Transfer and 

Advancement Act (NTTA) because this 

rulemaking does not involve technical 

standards; and 

• Executive Order 12898 (Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Populations, 59 FR 7629, 

Feb. 16, 1994) directs Federal agencies 

to identify and address 

‘‘disproportionately high and adverse 

human health or environmental effects’’ 

of their actions on minority populations 

and low-income populations to the 

greatest extent practicable and 

permitted by law. The EPA defines 

environmental justice (EJ) as ‘‘the fair 

treatment and meaningful involvement 

of all people regardless of race, color, 

national origin, or income with respect 

to the development, implementation, 

and enforcement of environmental laws, 

regulations, and policies.’’ The EPA 

further defines the term fair treatment to 

mean that ‘‘no group of people should 

bear a disproportionate burden of 

environmental harms and risks, 

including those resulting from the 

negative environmental consequences of 

industrial, governmental, and 

commercial operations or programs and 

policies.’’ The Kansas Department of 

Health and the Environment did not 

evaluate EJ considerations as part of its 

SIP submittal; the CAA and applicable 

implementing regulations neither 

prohibit nor require such an evaluation. 

The EPA did not perform an EJ analysis 

and did not consider EJ in this action. 

Due to the nature of the action being 

taken here, this action is expected to 

have a neutral impact on the air quality 

of the affected area. Consideration of EJ 

is not required as part of this action, and 

there is no information in the record 

inconsistent with the stated goal of E.O. 

12898 of achieving environmental 

justice for people of color, low-income 

populations, and Indigenous peoples. 

• This action does not have tribal 

implications as specified in Executive 

Order 13175. This action does not apply 

on any Indian reservation land, any 

other area where the EPA or an Indian 

tribe has demonstrated that a tribe has 

jurisdiction, or non-reservation areas of 

Indian country. Thus, Executive Order 

13175 does not apply to this action. 

List of Subjects in 40 CFR Part 52 

Environmental protection, Air 

pollution control, Carbon monoxide, 

Incorporation by reference, 

Intergovernmental relations, Lead, 

Nitrogen dioxide, Ozone, Particulate 

matter, Reporting and recordkeeping 

requirements, Sulfur oxides, Volatile 

organic compounds. 

Dated: December 19, 2023. 

Meghan A. McCollister, 

Regional Administrator, Region 7. 

[FR Doc. 2023–28384 Filed 12–29–23; 8:45 am] 

BILLING CODE 6560–50–P 


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