
[Federal Register Volume 82, Number 6 (Tuesday, January 10, 2017)]
[Rules and Regulations]
[Pages 3078-3129]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-00268]



[[Page 3077]]

Vol. 82

Tuesday,

No. 6

January 10, 2017

Part II





Environmental Protection Agency





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40 CFR Parts 51 and 52





Protection of Visibility: Amendments to Requirements for State Plans; 
Final Rule

  Federal Register / Vol. 82 , No. 6 / Tuesday, January 10, 2017 / 
Rules and Regulations  

[[Page 3078]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 51 and 52

[EPA-HQ-OAR-2015-0531; FRL-9957-05-OAR]
RIN 2060-AS55


Protection of Visibility: Amendments to Requirements for State 
Plans

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is finalizing 
revisions to requirements under the Clean Air Act (CAA) for state plans 
for protection of visibility in mandatory Class I Federal areas in 
order to continue steady environmental progress while addressing 
administrative aspects of the program. In summary, the revisions 
clarify the relationship between long-term strategies and reasonable 
progress goals (RPGs) in state implementation plans (SIPs) and the 
long-term strategy obligation of all states; clarify and modify the 
requirements for periodic comprehensive revisions of SIPs; modify the 
set of days used to track progress towards natural visibility 
conditions to account for events such as wildfires; provide states with 
additional flexibility to address impacts on visibility from 
anthropogenic sources outside the United States (U.S.) and from certain 
types of prescribed fires; modify certain requirements related to the 
timing and form of progress reports; and update, simplify and extend to 
all states the provisions for reasonably attributable visibility 
impairment, while revoking most existing reasonably attributable 
visibility impairment federal implementation plans (FIPs). The EPA also 
is making a one-time adjustment to the due date for the next periodic 
comprehensive SIP revisions by extending the existing deadline of July 
31, 2018, to July 31, 2021.

DATES: This final rule is effective on January 10, 2017.

ADDRESSES: The EPA established Docket ID No. EPA-HQ-OAR-2015-0531 for 
this action. All documents in the docket are listed in the http://www.regulations.gov Web site. Although listed in the index, some 
information is not publicly available, e.g., Confidential Business 
Information or other information whose disclosure is restricted by 
statute. Certain other material, such as copyrighted material, is not 
placed on the Internet and will be publicly available only in hard 
copy. Publicly available docket materials are available electronically 
in http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: For general information regarding this 
rule, contact Mr. Christopher Werner, Office of Air Quality Planning 
and Standards, U.S. Environmental Protection Agency, by phone at (919) 
541-5133 or by email at werner.christopher@epa.gov; or Ms. Rhea Jones, 
Office of Air Quality Planning and Standards, U.S. Environmental 
Protection Agency, by phone at (919) 541-2940 or by email at 
jones.rhea@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Preamble Glossary of Terms and Acronyms

    The following are abbreviations of terms used in this document.

AQRV Air quality related value
BART Best available retrofit technology
bext Light extinction
CAA Clean Air Act
CFR Code of Federal Regulations
EGU Electric generating unit
EPA Environmental Protection Agency
FIP Federal implementation plan
FLM or FLMs Federal Land Manager or Managers
ICR Information collection request
IMPROVE Interagency monitoring of protected visual environments
NAAQS National Ambient Air Quality Standards
NSR New Source Review
NOX Nitrogen oxides
OMB Office of Management and Budget
PM Particulate matter
PM2.5 Particulate matter equal to or less than 2.5 
microns in diameter (fine particulate matter)
PM10 Particulate matter equal to or less than 10 microns 
in diameter
PRA Paperwork Reduction Act
RHR Regional Haze Rule
RPG Reasonable progress goal
RPO Regional planning organization
SIP State implementation plan
SO2 Sulfur dioxide
TAR Tribal Authority Rule
URP Uniform rate of progress

B. Entities Affected by This Rule

    Entities potentially affected directly by this rule include state, 
local and tribal \1\ governments, as well as FLMs responsible for 
protection of visibility in mandatory Class I federal areas.\2\ 
Entities potentially affected indirectly by this rule include owners 
and operators of sources that emit particulate matter equal to or less 
than 10 microns in diameter (PM10), particulate matter equal 
to or less than 2.5 microns in diameter (PM2.5 or fine PM), 
sulfur dioxide (SO2), oxides of nitrogen (NOX), 
volatile organic compounds and other pollutants that may cause or 
contribute to visibility impairment. Others potentially affected 
indirectly by this rule include members of the general public who live, 
work or recreate in mandatory Class I areas affected by visibility 
impairment. Because emission sources that contribute to visibility 
impairment in Class I areas also may contribute to air pollution in 
other areas, members of the general public may also be affected by this 
rulemaking.
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    \1\ The EPA's visibility protection regulations may apply, as 
appropriate under the Tribal Authority Rule (TAR) in 40 CFR part 49, 
to an Indian tribe that receives a determination of eligibility for 
treatment as a state for purposes of administering a tribal 
visibility protection program under section 169A of the CAA. No 
tribe has applied for such status, and so at present the EPA is 
responsible for implementation of the visibility protection 
regulations in areas of tribal authority. This responsibility 
includes, but is not limited to, implementation of the reasonable 
progress requirements of 40 CFR 51.308(f), as necessary or 
appropriate. These rule changes may impact the development and 
approvability of tribal implementation plans that tribes may wish to 
submit in the future. We encourage states to provide outreach and 
engage in discussions with tribes about their regional haze SIPs as 
they are being developed.
    \2\ Areas 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 section 162(a). 
In accordance with section 169A of the CAA, the EPA, in consultation 
with the Department of Interior, promulgated a list of 156 areas 
where visibility is identified as an important value. 44 FR 69122 
(November 30, 1979). The extent of a mandatory Class I area includes 
subsequent changes in boundaries, such as park expansions. CAA 
section 162(a). Although states and tribes may designate as Class I 
additional areas that they consider to have visibility as an 
important value, the requirements of the visibility program set 
forth in section 169A of the CAA apply only to ``mandatory Class I 
Federal areas.'' Each mandatory Class I Federal area is the 
responsibility of a ``Federal Land Manager.'' CAA section 302(i). 
When we use the term ``Class I area'' in this action, we mean any 
one of the 156 ``mandatory Class I Federal areas'' where visibility 
has been identified as an important value, unless the context makes 
it clear that additional non-mandatory Federal Class I areas are 
also meant to be included.
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C. Obtaining a Copy of This Document and Other Related Information

    In addition to being available in the docket, an electronic copy of 
this Federal Register document will be posted at http://www.epa.gov/visibility. A ``track changes'' version of the full regulatory text 
that incorporates and shows the full context of the changes in this 
final action is also available in the docket for this rulemaking. In 
addition to the final and regulatory text documents, other relevant 
documents are located in the docket, including technical support 
documents referenced in this preamble.

[[Page 3079]]

D. Judicial Review

    Under CAA section 307(b)(1), judicial review of this final action 
is available only by filing a petition for review in the U.S. Court of 
Appeals for the District of Columbia Circuit by March 13, 2017. Under 
CAA section 307(d)(7)(B), any such judicial review is limited to only 
those objections that were raised with reasonable specificity in timely 
comments. Filing a petition for reconsideration by the Administrator of 
this final rule does not affect the finality of this action for 
purposes of judicial review, extend the time in which a petition for 
judicial review may be filed, or postpone the effectiveness of the 
rule. Under CAA section 307(b)(2), the requirements established by this 
final rule may not be challenged separately in any civil or criminal 
proceedings brought by the EPA to enforce the requirements.

E. Organization of This Federal Register Document

    The information presented in this document is organized as follows:

I. General Information
    A. Preamble Glossary of Terms and Acronyms
    B. Entities Affected by This Rule
    C. Obtaining a Copy of This Document and Other Related 
Information
    D. Judicial Review
    E. Organization of This Federal Register Document
    F. Background on This Rulemaking
II. Executive Summary
III. Overview of Visibility Protection Statutory Authority, 
Regulation and Implementation
    A. Visibility in Mandatory Class I Federal Areas
    B. Reasonably Attributable Visibility Impairment
    C. Regional Haze
    D. Air Permitting
IV. Final Rule Revisions
    A. Ongoing Litigation in Texas v. EPA
    B. Cooperative Federalism
    C. Clarifications To Reflect the EPA's Long-Standing 
Interpretation of the Relationship Between Long-Term Strategies and 
Reasonable Progress Goals
    D. Other Clarifications and Changes to Requirements for Periodic 
Comprehensive Revisions of Implementation Plans
    E. Changes to Definitions and Terminology Related to How Days 
Are Selected for Tracking Progress
    F. Impacts on Visibility From Anthropogenic Sources Outside the 
U.S.
    G. Impacts on Visibility From Wildland Fires
    H. Clarification of and Changes to the Required Content of 
Progress Reports
    I. Changes to Reasonably Attributable Visibility Impairment 
Provisions
    J. Consistency Revisions Related to Permitting of New and 
Modified Major Sources
    K. Changes to FLM Consultation Requirements
    L. Extension of Next Regional Haze SIP Deadline From 2018 to 
2021
    M. Changes to Scheduling of Regional Haze Progress Reports
    N. Changes to the Requirement That Regional Haze Progress 
Reports be SIP Revisions
    O. Changes to Requirements Related to the Grand Canyon 
Visibility Transport Commission
V. Environmental Justice Considerations
VI. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act (PRA)
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    K. Congressional Review Act (CRA)
VII. Statutory Authority

F. Background on This Rulemaking

    On May 4, 2016, the EPA proposed revisions to the 1999 Regional 
Haze Rule (RHR),\3\ which include clarifications and modifications to 
the requirements that states (and, if applicable, tribes) have to meet 
as they implement programs for the protection of visibility in 
mandatory Class I Federal areas, under sections 169A and 169B of the 
CAA. The EPA held public hearings on May 19, 2016, in Washington, DC 
and on June 1, 2016, in Denver, Colorado. States, industry, private 
citizens and non-governmental organizations submitted over 180,000 
comments. Based on EPA's review of the comments, we are finalizing most 
of the proposed revisions, but are also making some changes to respond 
to the concerns raised by commenters. These include: Changes to the 
proposed terminology used to refer to emissions inventories; changes to 
the proposed definitions and terminology related to how days are 
selected for tracking progress; changes to the proposed fire-related 
definitions and terminology; changes to the proposed required content 
of progress reports; changes to the proposed deadline for a state 
response to a reasonably attributable visibility impairment 
certification; the addition of a requirement for FLMs to consult with 
states prior to making a reasonably attributable visibility impairment 
certification; and minor changes to the requirements for FLM 
consultation on SIPs and progress reports. The EPA is issuing this 
final rule under section 307(d) of the CAA. Section 553(d) of the 
Administrative Procedure Act (APA), 5 U.S.C. Chapter 5, generally 
provides that rules may not take effect earlier than 30 days after they 
are published in the Federal Register. CAA section 307(d)(1) clarifies 
that: ``The provisions of section 553 through 557 * * * of Title 5 
shall not, except as expressly provided in this section, apply to 
actions to which this subsection applies.'' Thus, section 553(d) of the 
APA does not apply to this rule. The EPA has nevertheless considered 
the purposes underlying APA section 553(d) in making this rule 
effective upon publication. The primary purpose of the 30-day waiting 
period prescribed in section 553(d) is to give affected parties a 
reasonable time to adjust their behavior and prepare before the final 
rule takes effect. Notably, there are no specific obligations in the 
first thirty days of this regulatory action, and all obligations are 
established as of a date certain, rather than being tied to the 
effective date.
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    \3\ Here and elsewhere in this document, the terms ``Regional 
Haze Rule,'' ``1999 Regional Haze Rule'' and ``1999 RHR'' refer to 
the 1999 final rule (64 FR 35714), as amended in 2005 (70 FR 39156, 
July 6, 2005), 2006 (71 FR 60631, October 13, 2006) and 2012 (77 FR 
33656, June 7, 2012).
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    In addition, section 553(d) allows an effective date less than 30 
days after publication for a rule that ``grants or recognizes an 
exemption or relieves a restriction.'' An important aspect of this rule 
is the 3-year extension for state planning obligations. This extension 
is comparable to the grant of an exemption or relief from a restriction 
because it provides more time for states to meet a regulatory 
requirement. It is thus reasonable to make this action effective upon 
publication because states do not require an additional 30 days to 
adjust their behavior and prepare for the rule going into effect, and 
in fact will gain additional time to meet their planning obligations.

II. Executive Summary

    The CAA's visibility protection program, implemented through the 
rules at 40 CFR 51.300 through 51.309, helps to protect clear views in 
national parks, such as Grand Canyon National Park, and wilderness 
areas, such as the Okefenokee National Wildlife Refuge.

[[Page 3080]]

Vistas in these areas are often obscured by visibility-impairing 
pollutants caused by emissions from numerous sources located over a 
wide geographic area. States are required to submit periodic plans 
demonstrating how they have and will continue to make progress towards 
achieving their visibility improvement goals. The first state plans 
were due in 2007 and covered the 2008-2018 planning period.
    The EPA is making changes to the requirements that states (and, if 
applicable, tribes) have to meet for the second and subsequent 
implementation periods as they develop programs for the protection of 
visibility in mandatory Class I areas, consistent with CAA 
requirements. Implementation of the EPA's RHR (during the first 
implementation period) resulted in significant reductions in emissions 
and associated improvements in visibility in many Class I areas (see 
Section III.B of this document). This final rule supports continued 
environmental progress by retaining much of the 1999 RHR, clarifying or 
revising certain provisions of the visibility protection rules in 40 
CFR part 51, subpart P, and removing rule provisions that have been 
superseded by subsequent developments. An overview of the revisions is 
provided later, with additional details throughout this document.
    The EPA is clarifying the relationship between long-term strategies 
and RPGs in state plans and the long-term strategy obligations of all 
states. We are re-iterating that the CAA requires states to consider 
the four statutory factors (costs of compliance, time necessary for 
compliance, energy and non-air quality environmental impacts and 
remaining useful life) in each implementation period to determine the 
rate of progress towards natural visibility conditions that is 
reasonable for each Class I area. The rate of progress in some Class I 
areas may be meeting or exceeding the uniform rate of progress (URP) 
that would lead to natural visibility conditions by 2064, but this does 
not excuse states from conducting the required analysis and determining 
whether additional progress would be reasonable based on the four 
factors. The EPA is revising the RHR to address a number of issues, as 
discussed in the proposal, including: The way in which a set of days 
during each year is to be selected for purposes of tracking progress 
towards natural visibility conditions; aspects of the requirements for 
the content of progress reports; updating, simplifying and extending to 
all states the provisions for reasonably attributable visibility 
impairment and revoking FIPs adopted in the 1980s that require the EPA 
to assess and address any existing reasonably attributable visibility 
impairment situations in some states; and revising the requirement for 
states to consult with FLMs. Other changes address administrative 
aspects of the program in order to reduce unnecessary burden. These 
include the following: The EPA is finalizing a one-time adjustment to 
the due date for the next SIPs (from 2018 to 2021); revising the due 
dates for progress reports; and changing the requirement that progress 
reports be submitted as formal SIP revisions to documents that need not 
comply with the procedural requirements of 40 CFR 51.102, 40 CFR 51.103 
and Appendix V to Part 51--Criteria for Determining the Completeness of 
Plan Submissions. All of these changes apply to periodic comprehensive 
state implementation plans developed for the second and subsequent 
implementation periods and to progress reports submitted subsequent to 
those plans. These changes do not affect the development and review of 
state plans for the first implementation period or the first progress 
reports due under the 1999 RHR.
    The rationale for these changes is described more fully in the 
descriptions of each change detailed later in this action as well as in 
the preamble to the proposed rule.\4\ The revisions being finalized are 
informed by approximately 15 years of implementation of the CAA, 
numerous outreach sessions and stakeholder feedback regarding the 
regional haze program, and the many constructive comments we received 
on the proposal. The clarifications regarding the relationship between 
RPGs, long-term strategies and the long-term strategy obligation of all 
states are intended to ensure appropriate and consistent understanding 
of these requirements as states prepare their plans for the second 
implementation period. These clarifications reflect EPA's long-standing 
interpretation of the RHR, and are now being codified. The rule 
revisions related to how days are selected for visibility progress 
tracking will provide the public and state officials more meaningful 
information on how existing and potential new emission reduction 
measures are contributing or could contribute to reasonable progress in 
reducing man-made visibility impairment. Changes to FLM consultation 
requirements will help ensure that the expertise and perspective of 
these officials are brought into the state plan development process 
early enough that they can meaningfully contribute to the state's 
deliberations. Collectively, the changes being finalized now will 
ensure that the regional haze program is implemented consistent with 
CAA obligations, and ensure successful implementation during the second 
planning period and beyond.
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    \4\ 81 FR 26942 (May 4, 2016).
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    With regard to the extension of the deadline of July 31, 2018, to 
July 31, 2021, for states' comprehensive SIP revisions for the second 
implementation period, this one-time change will benefit states by 
allowing them to obtain and take into account information on the 
effects of a number of other regulatory programs that will be impacting 
sources over the next several years. The change will also allow states 
to develop SIP revisions for the second implementation period that are 
more integrated with state planning for these other programs, an 
advantage that was widely confirmed in early discussions with states 
and in comments submitted to the docket for this rulemaking. We 
anticipate that this change will result in greater environmental 
progress than if planning for these multiple programs were not as well 
integrated. The end date for the second implementation period remains 
2028, as was required by the 1999 RHR. Other than the one-time change 
to the next due date for periodic comprehensive SIP revisions, no 
change is being made for due dates for future periodic comprehensive 
SIP revisions.
    The changes related to progress reports are intended to make the 
timing of progress reports more useful as mid-course reviews, to 
clarify the required content of progress reports for aspects on which 
there has been some confusion, and to allow states to conserve their 
administrative resources and make submission of progress reports more 
timely by removing the requirement that they be submitted as formal SIP 
revisions. We are retaining a requirement that states consult with FLMs 
on their progress reports, and that states offer the public an 
opportunity to comment on progress reports before they are finalized, 
which are two of the steps that applied to progress reports when they 
were required to be SIP revisions, and which will help ensure ongoing 
accountability for progress reports. Please note that while the 
proposed rule included identical FLM consultation periods for progress 
reports and periodic comprehensive SIP revisions, FLM consultation 
requirements for SIP revisions and progress reports will differ going 
forward. This issue is described more fully in Section IV.K of this 
document.

[[Page 3081]]

    Finally, the 1999 RHR's provisions related to reasonably 
attributable visibility impairment required a recurring process of 
assessment and planning by the states. Experience since these 
provisions were promulgated suggests that situations involving 
reasonably attributable visibility impairment occur infrequently and 
therefore that an ``as needed'' approach for initiating a state 
planning obligation would be a more efficient use of resources. The EPA 
is finalizing its proposal to replace the recurring process of 
assessment of reasonably attributable visibility impairment with an as-
needed approach. The change to an as-needed approach only applies to 
reasonably attributable visibility impairment--periodic planning for 
purposes of regional haze will continue. In addition, in light of our 
increased understanding of the interstate nature of visibility 
impairment, we are expanding the applicability of the requirement to 
address reasonably attributable visibility impairment from only states 
with Class I areas to all states. If a situation exists or arises in 
which a source or a small number of sources in a state without any 
Class I area causes reasonably attributable visibility impairment at a 
Class I area in another state, this mechanism will ensure adequate 
visibility protection.

III. Overview of Visibility Protection Statutory Authority, Regulation 
and Implementation

A. Visibility in Mandatory Class I Federal Areas

    Reduction in visibility caused by emissions of PM10, 
PM2.5 (e.g., sulfates, nitrates, organic carbon, elemental 
carbon and soil dust) and their precursors (e.g., SO2, 
NOX and, in some cases, ammonia and volatile organic 
compounds) can take the form of either visibly distinct layers or 
plumes of pollution or more uniform ``regional haze.'' Fine particle 
precursors react in the atmosphere to form PM2.5, which 
along with directly emitted PM10 and PM2.5 
impairs visibility by scattering and absorbing light. This light 
scattering reduces the clarity, color and visible distance that one can 
see. Particulate matter can also cause serious health effects in humans 
(including premature death, heart attacks, irregular heartbeat, 
aggravated asthma, decreased lung function and increased respiratory 
symptoms) and contribute to environmental effects such as acid 
deposition and eutrophication.
    Data from the existing visibility monitoring network, the 
``Interagency Monitoring of Protected Visual Environments'' (IMPROVE) 
monitoring network, show that at the time the RHR was finalized in 
1999, visibility impairment caused by air pollution occurred virtually 
all the time at most national park and wilderness areas. The formally 
defined average visual range \5\ in many Class I areas in the western 
U.S. was 62-93 miles. In some Class I areas, these visual ranges may 
have been impacted by natural wildfire and dust episodes in addition to 
anthropogenic impacts. In most of the eastern Class I areas of the 
U.S., the average visual range was less than 19 miles.\6\
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    \5\ Visual range is the greatest distance, in kilometers or 
miles, at which a certain dark object can be discerned against the 
sky by a typical observer under certain defined conditions. Visual 
range defined in this highly controlled manner is inversely 
proportional to light extinction (bext) by particles and 
gases and is calculated as: Visual Range = 3.91/bext 
(Bennett, M.G., The physical conditions controlling visibility 
through the atmosphere; Quarterly Journal of the Royal 
Meteorological Society, 1930, 56, 1-29). Light extinction has units 
of inverse distance (i.e., Mm-1 or inverse Megameters 
(mega = 10\6\)). Under conditions other than those defined in this 
reference, people's ability to discern landscape features may vary 
and be different than implied by the value of the visual range as 
calculated from light extinction using this formula.
    \6\ 64 FR 35715 (July 1, 1999).
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    Based on visibility data through 2014, the visual range has 
increased 10 to 20 miles (4 to 7 deciviews) \7\ since the year 2000 in 
eastern Class I areas on the 20 percent haziest days. Some western 
Class I areas have also experienced visual range increases of 5 to 10 
miles (1 to 4 deciviews) on the 20 percent haziest days. However, in 
some areas, such as Sawtooth Wilderness area in Idaho, improvements 
from reduced emissions from man-made sources have been overwhelmed by 
impacts from wildfire and/or dust events. There are also some western 
areas where visibility has improved only by a slight amount or made no 
progress.
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    \7\ The deciview haze index (discussed in more detail in Section 
III.B.3 of this document) is logarithmically related to light 
extinction and is used by the regional haze program because it 
describes uniform differences in visibility across a range of 
visibility conditions.
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B. Reasonably Attributable Visibility Impairment

    In section 169A of the 1977 Amendments to the CAA, Congress enacted 
a program for protecting visibility in the nation's national parks, 
wilderness areas and other Class I areas due to their ``great scenic 
importance.'' \8\ Section 169A(a) of the CAA establishes as a national 
goal the ``prevention of any future, and the remedying of any existing, 
impairment of visibility in mandatory Class I Federal areas which 
impairment results from manmade air pollution.''
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    \8\ H.R. Rep. No. 294, 95th Cong. 1st Sess. at 205 (1977).
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    In 1980, the EPA promulgated regulations to address visibility 
impairment in Class I areas, including but not limited to impairment 
that is ``reasonably attributable'' to a single source or small group 
of sources, i.e., ``reasonably attributable visibility impairment.'' 
\9\ These regulations, codified at 40 CFR 51.300 through 51.307, 
represented the first phase in addressing visibility impairment from 
existing sources. They also addressed potential visibility impacts from 
new and modified major sources already subject to permitting 
requirements for purposes of protection of the National Ambient Air 
Quality Standards (NAAQS) and preventing significant deterioration of 
air quality.
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    \9\ 45 FR 80084 (December 2, 1980).
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    Notably, not all states were subject to the 1980 reasonably 
attributable visibility impairment requirements. Under the 1980 rules, 
the 35 states and one territory (Virgin Islands) containing Class I 
areas were required to submit SIPs addressing reasonably attributable 
visibility impairment. The 1980 rules required states to (1) develop, 
adopt, implement and evaluate long-term strategies for making 
reasonable progress toward remedying existing and preventing future 
impairment in the mandatory Class I areas through their SIP revisions; 
(2) adopt certain measures to assess potential visibility impacts due 
to new or modified major stationary sources, including measures to 
notify FLMs of proposed new source permit applications, and to consider 
visibility analyses conducted by FLMs in their new source permitting 
decisions; (3) conduct visibility monitoring in mandatory Class I 
areas, and (4) revise their SIPs at 3-year intervals to assure 
reasonable progress toward the national visibility goal. In addition, 
the 1980 regulations provided that an FLM may certify to a state at any 
time that visibility impairment at a Class I area is reasonably 
attributable to a single source or a small number of sources. Following 
such a certification by an FLM, a state was required to address the 
requirements for best available retrofit technology (BART) for BART-
eligible sources considered to be contributing to reasonably 
attributable visibility impairment. Also, the appropriate control of 
any source certified by an FLM, whether BART-eligible or not, would be 
specifically addressed in the long-term strategy for making reasonable 
progress toward the national goal of natural visibility conditions. See 
the

[[Page 3082]]

1980 rule's version of 40 CFR 51.302(c)(2)(i).
    In practice, the 1980 rules resulted in few SIPs being submitted by 
states and approved by the EPA, requiring the EPA to develop and apply 
FIPs to those states that failed to submit an approvable reasonably 
attributable visibility impairment SIP.\10\ Most of these FIPs 
contained planning requirements only. That is, most of the FIPs merely 
committed the EPA to assessing on a 3-year cycle whether reasonably 
attributable visibility impairment was occurring, and if so, to 
adopting an appropriate strategy of required emission controls.
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    \10\ 52 FR 45132 (November 24, 1987).
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C. Regional Haze

1. Requirements of the 1990 CAA Amendments and the EPA's Regional Haze 
Rule
    In 1990, Congress added section 169B to the CAA to further address 
regional haze issues. Among other things, this section included 
provisions for the EPA to conduct visibility research on regional 
regulatory tools with the National Park Service and other federal 
agencies, and to provide periodic reports to Congress on visibility 
improvements due to implementation of other air pollution protection 
programs. CAA section 169B also generally allowed the Administrator to 
establish visibility transport commissions and specifically required 
the Administrator to establish a commission for the Grand Canyon area. 
The EPA promulgated a rule to address regional haze in 1999.\11\ The 
1999 RHR established a more comprehensive visibility protection program 
for Class I areas. The requirements for regional haze are found at 40 
CFR 51.308 and 51.309.
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    \11\ 64 FR 35714 (July 1, 1999).
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    The requirement to submit a regional haze SIP applies to all 50 
states, the District of Columbia and the Virgin Islands.\12\ Congress 
subsequently amended the deadlines for regional haze SIPs, and the EPA 
adopted regulations requiring states to submit the first implementation 
plans addressing regional haze visibility impairment no later than 
December 17, 2007.\13\ These initial SIPs were to address emissions 
from certain large stationary sources and other requirements, which we 
discuss in greater detail later. Few states submitted a regional haze 
SIP by the December 17, 2007, deadline, and on January 15, 2009, the 
EPA found that 37 states, the District of Columbia and the Virgin 
Islands had failed to submit SIPs addressing the regional haze 
requirements.\14\ These findings triggered a requirement for the EPA to 
promulgate FIPs within 2 years unless a state submitted a SIP and the 
EPA approved that SIP within the 2-year period.\15\ Most states 
eventually submitted SIPs.
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    \12\ This requirement does not apply to other U.S. territories 
defined as ``states'' under the CAA because they do not have 
mandatory Class I Federal areas and are too distant from any such 
areas to affect them.
    \13\ 70 FR 39104 (July 6, 2005).
    \14\ 74 FR 2392 (January 15, 2009).
    \15\ CAA section 110(c).
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    The 1999 RHR also required states to submit periodic comprehensive 
revisions of their regional haze SIPs. Under 40 CFR 51.308(f) of the 
1999 RHR, states were required to submit the first such revision by no 
later than July 31, 2018, and every 10 years thereafter. These periodic 
comprehensive SIP revisions were required to address a number of 
elements, including current visibility conditions and actual progress 
made toward natural conditions during the previous implementation 
period; a reassessment of the effectiveness of the long-term strategy 
in achieving the RPGs over the prior implementation period; and 
affirmation of or revision to the RPGs. Further information on these 
periodic comprehensive SIP revisions can be found in Section III.B.3 of 
this document. In addition, the 1999 RHR's 40 CFR 51.308(g) required 
each state to submit progress reports, in the form of SIP revisions, 
every 5 years after the date of the state's initial SIP submission. In 
the progress reports, states were required to evaluate the progress 
made towards the RPGs for mandatory Class I areas located within the 
state, as well as those mandatory Class I areas located outside the 
state that may be affected by emissions from within the state. Further 
information on progress reports can be found in Section III.B.4 of this 
document.
    The 1999 RHR sought to improve efficiency and transparency by 
requiring states to coordinate planning under the 1980 reasonably 
attributable visibility impairment provisions with planning under the 
provisions added by the 1999 RHR. The states were directed to submit 
reasonably attributable visibility impairment SIPs every 10 years 
rather than every 3 years, and to do so as part of the newly required 
regional haze SIPs. Many, but not all, states submitted initial 
regional haze SIPs that committed to this coordinated planning process. 
Coordination of reasonably attributable visibility impairment and 
regional haze planning is described in more detail later.
2. Roles of Agencies in Addressing Regional Haze
    Successful implementation of the regional haze program requires 
long-term regional coordination among states, tribal governments and 
various federal agencies. As noted earlier, pollution affecting the air 
quality in Class I areas is emitted from many individual sources and 
can be transported over long distances, even hundreds of miles. 
Therefore, to effectively address the problem of visibility impairment 
in Class I areas, states need to develop strategies in coordination 
with one another, taking into account the effect of emissions from one 
jurisdiction on the air quality in another.
    Because the pollutants that lead to regional haze can originate 
from sources located across broad geographic areas, and because these 
sources may be numerous and emit amounts of pollutants that, even 
though small, contribute to the collective whole, the EPA encourages 
states to address visibility impairment from a regional perspective. 
Five regional planning organizations (RPOs) were formed after the 
promulgation of the RHR in 1999 to address regional haze and related 
issues: The Central Regional Air Planning Association, the Mid-
Atlantic/Northeast Visibility Union, the Midwest Regional Planning 
Organization, the Western Regional Air Partnership and the Visibility 
Improvement State and Tribal Association of the Southeast.\16\ The RPOs 
first evaluated technical information to better understand how their 
states and tribes impact Class I areas across the country, and then 
supported the development (by states) of regional strategies to reduce 
emissions of pollutants that lead to regional haze.
---------------------------------------------------------------------------

    \16\ See ``Visibility--Regional Planning Organizations,'' 
available at https://www.epa.gov/visibility/visibility-regional-planning-organizations.
---------------------------------------------------------------------------

3. Requirements for the Regional Haze SIPs
    As mentioned earlier, states were required to submit SIPs 
addressing regional haze visibility impairment in 2007, which covered 
what we refer to as the first implementation period (2008-2018). A 
focus of the 2007 SIP obligation was to give specific attention to 
certain stationary sources that were in existence on August 7, 1977, 
but were not in operation before August 7, 1962, by requiring these 
sources, where appropriate, to install BART controls for the purpose of 
eliminating or reducing visibility impairment. These SIPs included a 
number of components and/

[[Page 3083]]

or analyses, which are described later along with information regarding 
whether or not this final rule impacts that particular SIP element.
    BART Requirement. Section 169A of the CAA directs states to 
evaluate the use of retrofit controls at certain larger, often 
uncontrolled, older stationary sources in order to address visibility 
impacts from these sources. Specifically, section 169A(b)(2)(A) of the 
CAA requires states to revise their SIPs to include such measures as 
may be necessary to make reasonable progress towards the natural 
visibility goal, including a requirement that certain categories of 
existing major stationary sources \17\ procure, install and operate 
BART. Under the RHR, the EPA directed states to conduct BART 
determinations for any ``BART-eligible'' sources \18\ that may be 
anticipated to cause or contribute to any visibility impairment in a 
Class I area. The EPA published the Guidelines for BART Determinations 
Under the Regional Haze Rule at appendix Y to 40 CFR part 51 
(hereinafter referred to as the ``BART Guidelines'') to assist states 
in determining which of their sources should be subject to the BART 
requirements and in determining appropriate emission limits for each 
applicable source.\19\ The 1999 RHR also gave states the flexibility to 
adopt an emissions trading program or other alternative program in lieu 
of source-specific BART as long as the alternative provided greater 
reasonable progress towards improving visibility than BART and met 
certain other requirements set out in the 1999 RHR's 40 CFR 
51.308(e)(2).
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    \17\ The set of ``major stationary sources'' potentially 
subject-to-BART is listed in CAA section 169A(g)(7).
    \18\ BART-eligible sources are those sources that have the 
potential to emit 250 tons or more of a visibility-impairing air 
pollutant, were not in operation prior to August 7, 1962, but were 
in existence on August 7, 1977, and whose operations fall within one 
or more of 26 specifically listed source categories. 40 CFR 51.301.
    \19\ 70 FR 39104 (July 6, 2005).
---------------------------------------------------------------------------

    States were required to undertake the BART determination process 
during the first implementation period. The BART requirement was a one-
time requirement, but a BART-eligible source may need to be re-assessed 
for additional controls in future implementation periods under the 
CAA's reasonable progress provisions. Specifically, we anticipate that 
a number of BART-eligible sources that installed only moderately 
effective controls (or no controls at all) will need to be reassessed. 
Under the 1999 RHR's 40 CFR 51.308(e)(5), BART-eligible sources are 
subject to the requirements of 40 CFR 51.308(d), which addresses 
regional haze SIP requirements for the first implementation period, in 
the same manner as other sources going forward.\20\
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    \20\ Under the 1999 RHR's 40 CFR 51.308(e)(5), BART-eligible 
sources were subject to the requirements of 40 CFR 51.308(d), which 
addresses regional haze SIP requirements for the first 
implementation period, in the same manner as other sources going 
forward.
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    Visibility Metric. The RHR established the 24-hour deciview haze 
index as the principal metric or unit for expressing visibility on any 
particular day.\21\ The deciview haze index is calculated from light 
extinction values and expresses uniform changes in the degree of haze 
in terms of common increments across the entire range of visibility 
conditions, from pristine to extremely hazy. Deciview values are 
calculated by using air quality measurements to estimate light 
extinction, most recently using the revised IMPROVE algorithm, and then 
transforming the value of light extinction using a logarithmic 
function.\22\ The deciview is a more useful measure for comparing days 
and tracking progress in improving visibility than light extinction 
itself because each deciview change is an equal incremental change in 
visibility typically perceived by a human observer. Most people can 
detect a change in visibility of one deciview. The preamble to the 1999 
RHR provided additional details about the deciview haze index.
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    \21\ See 70 FR 39104, 39118.
    \22\ Pitchford, M.; Malm, W.; Schichtel, B.; Kumar, N.; 
Lowenthal, D.; Hand, J. Revised algorithm for estimating light 
extinction from IMPROVE particle speciation data; J. Air & Waste 
Manage. Assoc. 2007, 57, 1326-1336; doi: 3155/1047-3289.57.11.1326.
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    Baseline, Current and Natural Conditions and Tracking Changes in 
Visibility. To track changes in visibility over time at each of the 156 
Class I areas covered by the visibility program (40 CFR 81.401-437), 
and as part of the process for determining reasonable progress, states 
were required to calculate visibility conditions at each Class I area 
for a 5-year period just preceding each periodic comprehensive SIP 
revision.\23\ To do this, the 1999 RHR required states to determine 
average visibility conditions (in deciviews) for the 20 percent least 
impaired days and the 20 percent most impaired days over the 5-year 
period at each of their Class I areas.
---------------------------------------------------------------------------

    \23\ Under the 1999 RHR, states were also required to 
periodically review progress in reducing impairment every 5 years.
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    States were also required to develop an estimate of natural 
visibility conditions for the purpose of estimating progress toward the 
national goal. Natural visibility is determined by estimating the 
natural concentrations of pollutants that cause visibility impairment 
and then calculating total light extinction based on those estimates. 
The EPA has provided guidance to states regarding how to calculate 
baseline, natural and current visibility conditions at each Class I 
area.\24\ After the EPA issued this guidance, a number of interested 
parties together developed a set of alternative estimates of natural 
conditions using a more refined approach (known as ``NC-II''), which 
were used by most states in their first regional haze SIPs with EPA 
approval.\25\
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    \24\ Guidance for Estimating Natural Visibility Conditions Under 
the Regional Haze Rule, September 2003, EPA-454/B-03-005, available 
at http://www3.epa.gov/ttn/caaa/t1/memoranda/rh_envcurhr_gd.pdf; and 
Guidance for Tracking Progress Under the Regional Haze Rule, 
September 2003, EPA-454/B-03-004, available at http://www3.epa.gov/ttn/oarpg/t1/memoranda/rh_tpurhr_gd.pdf.
    \25\ Regional Haze Rule Natural Level Estimates Using the 
Revised IMPROVE Aerosol Reconstructed Light Extinction Algorithm, 
available at http://vista.cira.colostate.edu/improve/Publications/GrayLit/032_NaturalCondIIpaper/Copeland_etal_NaturalConditionsII_Description.pdf; Revised IMPROVE 
Algorithm for Estimating Light Extinction from Particle Speciation 
Data, available at http://vista.cira.colostate.edu/improve/Publications/GrayLit/019_RevisedIMPROVEeq/RevisedIMPROVEAlgorithm3.doc; and Regional Haze Data Analysis 
Workshop, June 8, 2005, Denver, CO, agenda and documents available 
at http://www.wrapair.org/forums/aamrf/meetings/050608den/index.html.
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    Baseline visibility conditions reflect the degree of visibility 
impairment for the 20 percent least impaired days and 20 percent most 
impaired days for each calendar year from 2000 to 2004. Using 
monitoring data for 2000 through 2004, states are required to calculate 
the average degree of visibility impairment for each Class I area, 
based on the average of annual values of these two metrics over the 5-
year period. The comparison of baseline visibility conditions to 
natural visibility conditions indicates the amount of improvement that 
would be necessary to attain natural visibility. Over time, the 
comparison of current visibility conditions \26\ to the baseline 
visibility conditions will indicate the amount of progress that has 
been made.
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    \26\ Given the required timing of the first regional haze SIPs 
that were due by December 17, 2007, ``baseline visibility 
conditions'' were also the ``current'' visibility conditions. For 
future SIPs, ``current conditions'' will be updated to the 5-year 
period just preceding the SIP revision.
---------------------------------------------------------------------------

    The 1999 RHR defined ``visibility impairment'' as a humanly 
perceptible change (i.e., difference) in visibility from that which 
would have existed under natural conditions. The rule directed the 
tracking of visibility

[[Page 3084]]

impairment on the 20 percent ``most impaired days'' and 20 percent 
``least impaired days'' in order to determine progress towards natural 
visibility conditions. 40 CFR 51.308(d)(2)(i-iv). In light of the 1999 
RHR's definition of ``impairment,'' the term ``impaired'' in the 
phrases ``most impaired days'' and ``least impaired days'' could be 
taken to mean anthropogenic impairment only and to exclude reductions 
in visibility attributable to natural emission sources. However, the 
preamble to the 1999 RHR stated that the least and most impaired days 
were to be selected as the monitored days with the lowest and highest 
actual deciview levels caused by all sources, respectively. In 2003, 
the EPA issued guidance describing in detail the steps necessary for 
selecting and calculating light extinction on the ``worst'' and 
``best'' visibility days, and this guidance also indicated that the 
monitored days with the lowest and highest actual deciview levels were 
to be selected as the least and most impaired days.\27\ This approach 
worked well in many Class I areas but caused some concerns in other 
areas.
---------------------------------------------------------------------------

    \27\ Guidance for Tracking Progress Under the Regional Haze 
Rule, September 2003, http://www3.epa.gov/ttnamti1/files/ambient/visible/tracking.pdf
---------------------------------------------------------------------------

    Specifically, the ``worst'' visibility days in some Class I areas 
can be impacted by irregularly occurring natural emissions (e.g., 
wildland wildfires and dust storms). These natural contributions to 
haze vary in magnitude and timing. Anticipating this variability, in 
the 1999 RHR the EPA decided to use 5-year averages of visibility data 
to minimize the impacts of the interannual variability in natural 
events. However, additional data available through the IMPROVE 
monitoring network indicate that in many Class I areas 5-year averages 
are not sufficient for minimizing these erratic impacts. As a result, 
visibility improvements resulting from decreases in anthropogenic 
emissions can be hidden by this natural variability. Further, because 
of the logarithmic deciview scale, changes in PM concentrations and 
light extinction due to reductions in anthropogenic emissions have 
little effect on the deciview value on days with high PM concentrations 
and light extinction due to natural sources. The use of the days with 
the highest deciview index values, without consideration of the source 
of the visibility impacts, thus created difficulties when attempting to 
track visibility improvements resulting from controls on anthropogenic 
sources. States identified this difficulty prior to the start of this 
rulemaking and asked that the EPA explore options for focusing the 
visibility tracking metric on the effect of controlling anthropogenic 
emissions. To help states minimize the impacts of emissions from 
natural sources on visibility tracking via an approach that is also 
consistent with the CAA's goal to reduce visibility impairment 
resulting from man-made air pollution, the EPA proposed to more 
explicitly (and consistently) address this issue for future 
implementation periods.
    Reasonable Progress Goals and Long-Term Strategy. To ensure 
continuing progress towards achieving the natural visibility goal, the 
1999 RHR required that each SIP submission in the series of periodic 
comprehensive regional haze SIPs establish two distinct RPGs (one for 
the most impaired and one for the least impaired days) for every Class 
I area. See 40 CFR 51.308(d)(1). The 1999 RHR did not mandate specific 
milestones or rates of progress, but instead called for states to 
establish goals that provide for ``reasonable progress'' toward 
achieving natural visibility conditions. Specifically, states were 
required to provide for an improvement in visibility for the most 
impaired days over the period of the SIP, and ensure no degradation in 
visibility for the least impaired days over the same period.
    To set their RPGs, states were required to consider the four 
statutory reasonable progress factors: (1) The costs of compliance; (2) 
the time necessary for compliance; (3) the energy and non-air quality 
environmental impacts of compliance; and (4) the remaining useful life 
of any potentially affected sources. States were required to 
demonstrate in their SIPs how these factors were considered when 
selecting the RPGs for the least impaired and most impaired days for 
each applicable Class I area. The RPGs are not enforceable.\28\
---------------------------------------------------------------------------

    \28\ 64 FR 35754.
---------------------------------------------------------------------------

    Consistent with the requirement in section 169A(b) of the CAA that 
states include in their regional haze SIPs a 10- to 15-year strategy 
for making reasonable progress, 40 CFR 51.308(d)(3) of the 1999 RHR 
required states to include a long-term strategy in their regional haze 
SIPs. Under the 1999 RHR, a state's long-term strategy is inextricably 
linked to the RPGs because the long-term strategy ``must include 
enforceable emission limitations, compliance schedules, and other 
measures as necessary to achieve the reasonable progress goals 
established by states having mandatory Class I Federal areas.'' 40 CFR 
51.308(d)(3).
    When setting their RPGs, states were also required to consider the 
rate of progress for the most impaired days that would be needed to 
reach natural visibility conditions by 2064 and the emission reduction 
measures that would be needed to achieve that rate of progress over the 
approximately 10-year period of the SIP. The purpose of this 
requirement was to 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. If a state's RPG for the most impaired days 
achieved progress that was equal to the URP, the RPG would be ``on the 
URP line'' \29\ or ``on the glidepath.'' If a state's RPG for the most 
impaired days was not on the glidepath, 40 CFR 51.308(d)(1)(ii) 
required the state to demonstrate that it would not be reasonable to 
require additional control measures and adopt an RPG that would be on 
the glidepath. The 1999 RHR did not establish an enforceable 
requirement that natural conditions be reached by 2064. The EPA 
approved a number of SIPs for the first implementation period that 
projected that continued progress at the rate expected to be achieved 
during the first period would not result in natural conditions until 
after 2064. However, the EPA also disapproved some SIPs during the 
first implementation period where states argued that no analysis of the 
four factors was necessary because visibility was projected to be 
``below the glidepath'' at the end of the implementation period even 
without additional measures.\30\
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    \29\ The URP for the most impaired days can be represented in a 
graphical manner by drawing the ``URP line'' on a chart with 
calendar year on the horizontal axis and deciviews for the 20 
percent most impaired day on the vertical axis.
    \30\ 76 FR 64186 at 64195 (October 17, 2011) (proposed action on 
Arkansas's RPGs), 77 FR 14604 at 14612 (March 12, 2012) (final 
action on Arkansas's RPGs).
---------------------------------------------------------------------------

    In setting their RPGs, each state with one or more Class I areas 
was also required to consult with potentially ``contributing states,'' 
i.e., other nearby states with emission sources that may be affecting 
visibility impairment in the state's Class I areas. In such cases, the 
contributing state was required to demonstrate that it included in its 
long-term strategy all measures necessary to obtain its share of the 
emission reductions needed to make reasonable progress at the Class I 
area.\31\ In

[[Page 3085]]

determining whether the upwind and downwind states' long-term 
strategies and RPGs provided for reasonable progress toward natural 
visibility conditions, the EPA was required to evaluate the 
demonstrations developed by the state. 40 CFR 51.308(d)(1).
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    \31\ This consultation obligation is a key element of the 
regional haze program. Congress, the states, the courts and the EPA 
have long recognized that regional haze is a regional problem that 
requires regional solutions. Vermont v. Thomas, 850 F.2d 99, 101 (2d 
Cir. 1988). Ultimately, early actions by states such as Vermont were 
influential in Congressional enactment of section 169B of the CAA in 
1990. Congress intended this provision of the CAA to ``equalize the 
positions of the States with respect to interstate pollution,'' (S. 
Rep. No. 95-127, at 41 (1977)) and our interpretation accomplishes 
this goal by ensuring that downwind states can seek recourse from us 
if upwind states are not doing enough to address visibility 
transport.
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    The 1999 RHR required states to consider all types of anthropogenic 
sources of visibility impairment when developing their long-term 
strategies, including major and minor stationary sources, mobile 
sources and area sources. States had to consider a number of factors 
when developing their long-term strategies, including: (1) Emission 
reductions due to ongoing air pollution control programs, including 
measures to address reasonably attributable visibility impairment; (2) 
measures to mitigate the impacts of construction activities; (3) 
emissions limitations and schedules for compliance; (4) source 
retirement and replacement schedules; (5) smoke management techniques 
for agricultural and forestry management purposes; (6) the 
enforceability of emissions limitations and control measures; and (7) 
the anticipated net effect on visibility due to projected changes in 
point, area and mobile source emissions over the period addressed by 
the long-term strategy. 40 CFR 51.308(d)(3)(v).
    Coordinating Regional Haze and Reasonably Attributable Visibility 
Impairment. The 1999 RHR fulfilled the EPA's responsibility to put in 
place a national regulatory program that addresses both reasonably 
attributable visibility impairment and regional haze. As part of the 
1999 RHR, the EPA revised the schedule in 40 CFR 51.306(c) for the 
periodic review of reasonably attributable visibility impairment SIPs. 
The revised version of this subsection required that the reasonably 
attributable visibility impairment plan must continue to provide for a 
periodic review and SIP revision not less frequently than every 3 years 
until the date of submission of the state's first plan addressing 
regional haze visibility impairment. On or before this date, the state 
must have revised its plan to provide for periodic review and revision 
of a coordinated long-term strategy for addressing reasonably 
attributable visibility impairment and regional haze, and the state 
must have submitted the first such coordinated long-term strategy with 
its first regional haze SIP. Under the 1999 RHR, states were required 
to submit future coordinated long-term strategies, and periodic 
progress reports evaluating progress towards RPGs. The state's periodic 
review of its long-term strategy was required to report on both 
regional haze visibility impairment and reasonably attributable 
visibility impairment and was required to be submitted to the EPA in 
the form of a periodic comprehensive SIP revision. Under our proposed 
changes to the reasonably attributable visibility impairment 
provisions, this coordinated approach to a state's long-term strategies 
for regional haze and reasonably attributable visibility impairment 
would continue, but will apply in the infrequent case that a state 
receives a certification of reasonably attributable visibility 
impairment.
    Monitoring Strategy and Other Implementation Plan Requirements. 40 
CFR 51.308(d)(4) of the 1999 RHR included the requirement for a 
monitoring strategy for measuring, characterizing and reporting of 
regional haze visibility impairment that is representative of all 
mandatory Class I areas within the state. The strategy was required to 
be coordinated with the monitoring strategy required in the 1999 RHR 
version of 40 CFR 51.305 for reasonably attributable visibility 
impairment. Compliance with this requirement could be met through 
``participation'' in the IMPROVE network.\32\ A state's participation 
in the IMPROVE network includes state support for the use of CAA state 
and tribal assistance grants funds to partially support the operation 
of the IMPROVE network as well as the state's review and use of 
monitoring data from the network. The monitoring strategy was due with 
the first regional haze SIP, and under the 1999 RHR it must be reviewed 
every 5 years as part of the progress reports. The monitoring strategy 
must also provide for additional monitoring sites if the IMPROVE 
network is not sufficient to determine whether RPGs will be met. To 
date, neither the EPA nor any state has concluded that the IMPROVE 
network is not sufficient in this way. The evolution of the IMPROVE 
network will be guided by a Steering Committee that has FLM, EPA and 
state participation, within the evolving context of available 
resources. It is the EPA's objective that individual states will not be 
required to commit to providing monitoring sites beyond those planned 
to be operated by the IMPROVE program during the period covered by a 
SIP revision. Further, if the IMPROVE program must discontinue a 
monitoring site, this would not be a basis for an approved regional 
haze SIP to be found inadequate; but rather, the state, the federal 
agencies and the IMPROVE Steering Committee should work together to 
address the RHR requirements when the next SIP revision is developed. 
As described in Section IV.H of this document, we proposed that 
progress reports from individual states no longer be required to review 
and modify as necessary the state's monitoring strategy. The IMPROVE 
Steering Committee structure, the requirement to review the monitoring 
strategy as part of the periodic comprehensive SIP revision, and the 
requirement for a state to consider any recommendations from the EPA or 
a FLM for additional monitoring for purposes of reasonably attributable 
visibility impairment will be sufficient to achieve the objective of 
the current progress report requirement to review the monitoring 
strategy.
---------------------------------------------------------------------------

    \32\ While compliance with 40 CFR 51.308(d)(4) for regional haze 
may be met through participation in the IMPROVE network, additional 
analysis or techniques beyond participation in IMPROVE may be 
required for compliance with 40 CFR 51.305 for reasonably 
attributable visibility impairment.
---------------------------------------------------------------------------

    Consultation Between States and FLMs. The 1999 RHR required that 
states consult with FLMs before adopting and submitting their SIPs. 40 
CFR 51.308(i). There are two parts to this requirement. First, states 
must provide FLMs an opportunity for an in-person consultation meeting 
at least 60 days prior to holding any public hearing on the SIP. This 
consultation meeting was required to include the opportunity for the 
FLMs to discuss their assessment of impairment of visibility in any 
Class I area and to offer recommendations on the development of the 
RPGs and on the development and implementation of strategies to address 
visibility impairment. Further, a state was required to include in its 
SIP a description of how it addressed any comments provided by the 
FLMs. We proposed to require that states offer the opportunity for this 
already-required in-person consultation meeting early enough that 
information and recommendations provided by the FLMs can meaningfully 
inform the state's decisions on the long-term strategy. The second part 
of the consultation requirement is that a SIP 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, progress reports, and the implementation of other 
programs having the potential to contribute to impairment of visibility 
in Class I areas.

[[Page 3086]]

We did not propose any change to this requirement for procedures for 
continuing consultation. This continuing consultation should provide 
opportunities for FLM input on the scope and methods for the state's 
technical analyses as they are being planned, while the in-person 
consultation meeting required by the first part of the consultation 
requirement will occur as a state is making decisions based on the 
conclusions of its technical analyses. FLMs often participate in multi-
state workgroups on regional haze and related issues and attend multi-
state meetings on these topics, which further facilitates collaboration 
with individual states during SIP development.
4. Requirements for the Regional Haze Progress Reports
    The 1999 RHR included provisions for progress reports to be 
submitted at 5-year intervals, counting from the submission of the 
first required SIP revision by the particular state. The requirements 
for these reports were included for most states in 40 CFR 51.308(g) and 
(h). Three western states (New Mexico, Utah and Wyoming) exercised an 
option provided in the RHR to meet alternative requirements contained 
in 40 CFR 51.309 for their SIPs. For these three states, the 
requirements for the content of the 5-year progress reports are 
identical to those for the other states, but for these states the 
requirements for the reports were contained in 40 CFR 51.309(d)(10). 
This section specifies fixed due dates in 2013 and 2018 for these 
progress reports. The 1999 RHR then provided that these three states 
will revert to the progress report requirements in 40 CFR 51.308 after 
the report currently due in 2018. We did not propose this aspect of the 
RHR.
    An explanation of the 5-year progress reports is provided in the 
preamble to the 1999 RHR.\33\ This 5-year review was intended to 
provide an interim report on the implementation of, and if necessary 
mid-course corrections to, the regional haze SIP, which is generally 
prepared in 10-year increments. The progress report provides an 
opportunity for public input on the state's (and the EPA's) assessment 
of whether the approved regional haze SIP is being implemented 
appropriately and whether reasonable visibility progress is being 
achieved consistent with the projected visibility improvement in the 
SIP.
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    \33\ 64 FR 35747 (July 1, 1999).
---------------------------------------------------------------------------

    Required elements of the progress report under the 1999 RHR 
included: The status of implementation of all measures included in the 
regional haze SIP; a summary of the emissions reductions achieved 
throughout the state; an assessment of current visibility conditions 
and the change in visibility impairment over the past 5 years; an 
analysis tracking the change over the past 5 years in emissions of 
pollutants contributing to visibility impairment from all sources and 
activities within the state; an assessment of any significant changes 
in anthropogenic emissions within or outside the state that have 
occurred over the past 5 years that have limited or impeded progress in 
reducing pollutant emissions and improving visibility; an assessment of 
whether the current SIP elements and strategies are sufficient to 
enable the state (or other states with mandatory Class I areas affected 
by emissions from the state) to meet all established RPGs; a review of 
the state's visibility monitoring strategy and any modifications to the 
strategy as necessary; and a determination of the adequacy of the 
existing SIP (including taking one of four possible actions).\34\ We 
proposed to include a number of clarifications and changes to the 
requirements for the content of progress reports.
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    \34\ 40 CFR 51.308(g). See also General Principles for the 5-
Year Regional Haze Progress Reports for the Initial Regional Haze 
State Implementation Plans (Intended to Assist States and EPA 
Regional Offices in Development and Review of the Progress Reports), 
April 2013, EPA-454/B-03-005, available at https://www.epa.gov/sites/production/files/2016-03/documents/haze_5year_4-10-13.pdf, 
(hereinafter referred to as ``our 2013 Progress Report Guidance'').
---------------------------------------------------------------------------

    Under the 1999 RHR's 40 CFR 51.308(g) and 40 CFR 51.309(d)(10), 
progress reports must take the form of SIP revisions, so states must 
follow formal administrative procedures (including public review and 
opportunity for a public hearing) before formally submitting the 5-year 
progress report to the EPA. See 40 CFR 51.102, 40 CFR 51.103, and 
Appendix V to Part 51--Criteria for Determining the Completeness of 
Plan Submissions. We proposed to remove the requirement that progress 
reports be submitted as SIP revisions.
    In addition, because progress reports were SIP revisions under the 
1999 RHR, states were required to provide FLMs with an opportunity for 
in-person consultation at least 60 days prior to any public hearing on 
progress report. See 1999 RHR version of 40 CFR 51.308(i)(2) and (3). 
Procedures must also be provided for continuing consultation between 
the state and FLM regarding development and review of progress reports. 
See 40 CFR 51.308(i)(4).
    Under the 1999 RHR, the first progress reports were due 5 years 
from the initial SIP submittal (with the next progress reports for New 
Mexico, Utah, and Wyoming due in 2018). Most of these deadlines have 
already passed although some are due in 2016 and in 2017.\35\
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    \35\ A number of first progress reports have been submitted by 
states. Several of these progress reports have been approved, action 
on several others has been proposed, and EPA is still reviewing the 
other submitted reports. There are also states for which progress 
reports are overdue, and a few states for which progress reports are 
not yet due and have not been submitted.
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5. Tribes and Regional Haze
    Tribes have a distinct interest in regional haze due to the effects 
of visibility impairment on tribal lands as well as on other lands of 
high value to tribal members, such as landmarks considered sacred. 
Tribes, therefore, have a strong interest in emission control measures 
that states and the EPA incorporate into SIPs and FIPs with regard to 
regional haze, and also have an interest in the state response to any 
certification of reasonably attributable visibility impairment made by 
an FLM.\36\ The agency has a tribal consultation policy that covers any 
plan that the EPA would promulgate that may affect tribal interests. 
This consultation policy applies to situations where a potentially 
affected source is located on tribal land, as well as situations where 
a SIP or FIP concerns a source that is located on state land and may 
affect tribal land or other lands that involve tribal interests. In 
addition, the EPA has and will continue to consider any tribal comments 
on any proposed action on a SIP or FIP.
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    \36\ Like the EPA, the Department of the Interior and the U.S. 
Forest Service in the U.S. Department of Agriculture have strong 
tribal consultation policies. See: http://www.epa.gov/tribal/consultation/index.htm; http://www.fs.fed.us/spf/tribalrelations/authorities.shtml, and https://www.doi.gov/tribes/Tribal-Consultation-Policy.
---------------------------------------------------------------------------

    In the first implementation period for regional haze SIPs, the 
partnerships within the RPOs included strong relationships between the 
states and the tribes, and the EPA encourages states to continue to 
invest in those relationships (including consulting with tribes), 
particularly with respect to tribes located near Class I areas. States 
should continue working directly with tribes on their SIPs and their 
response to any certification of reasonably attributable visibility 
impairment made by an FLM. It is preferable for states to address 
tribal concerns during their planning process rather than the EPA 
addressing such concerns in its subsequent rulemaking process. During 
the development of this rulemaking, the EPA was asked by the

[[Page 3087]]

National Tribal Air Association to adopt a requirement that states 
formally consult with tribes during the development of their regional 
haze SIPs. The CAA does not explicitly authorize the EPA to impose such 
a requirement on the states. While we recognize the value of dialogue 
between state and tribal representatives, we did not propose to require 
it.

D. Air Permitting

    One part of the visibility protection program, 40 CFR 51.307, New 
Source Review (NSR), was established in 1980 with the rationale that 
while most new sources that may impair visibility were already subject 
to review under the Prevention of Significant Deterioration provisions 
(part C of Title I of the CAA), additional regulations would ``ensure 
that certain sources exempt from the PSD regulations because of 
geographic criteria will be adequately reviewed for their potential 
impact on visibility in the mandatory Class I Federal area.'' \37\ The 
EPA explained at proposal that this was necessary because the PSD 
regulations did not call for the review of major emitting facilities 
(or major modifications) located in nonattainment areas,\38\ and that 
it was appropriate to ``clarify certain procedural relationships 
between the FLM and the state in the review of new source impacts on 
visibility in Federal class I areas.'' \39\ The EPA envisioned that 
state and FLM consultation would commence with the state notifying the 
FLM of a potential new source, and that consultation would continue 
throughout the permitting process. We proposed to revise 40 CFR 51.307 
only as needed to maintain consistency with revisions to other sections 
of 40 CFR part 50 subpart P.
---------------------------------------------------------------------------

    \37\ 45 FR 80084 (December 2, 1980).
    \38\ In 1978, PSD rules were put in place that required 
permitting agencies to interact with FLMs and for air quality 
related values (AQRVs) to be taken into consideration in the PSD 
permitting process. 43 FR 26380 (June 19, 1978). Those PSD rules did 
not cover sources in nonattainment areas, and while there were EPA 
rules for nonattainment NSR in existence, they did not require 
consideration of Class I areas. In 1979, 40 CFR part 51, appendix S 
established rules for nonattainment permitting, but they did not 
(and still do not) require consideration of visibility or FLM 
notification. (The same is also true of a more recent addition, 40 
CFR 51.165. Where applicable to nonattainment areas, this rule does 
not require Class I reviews. While 40 CFR 51.165(b) requires that 
sources located in attainment areas cannot cause or contribute to a 
NAAQS violation anywhere, this does not cover AQRVs in Class I 
areas.) As a result, in 1980, the EPA added requirements to 40 CFR 
51.307 for notification of FLMs of pending permits for new sources 
in nonattainment areas.
    \39\ 45 FR 34765 (May 22, 1980).
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IV. Final Rule Revisions

    The EPA is finalizing revisions to the agency's visibility 
regulations that are intended to build upon the progress achieved by 
the visibility program over the last decade while streamlining certain 
administrative requirements that are unnecessarily burdensome. The EPA 
gained a substantial amount of knowledge during the first regional haze 
implementation period and learned what aspects of the program work well 
and what aspects could benefit from modification. The EPA received 
information and perspectives from air agencies and FLMs during this 
period that were invaluable in developing the proposal. We also 
received comments from a wide variety of other stakeholders during the 
public comment process, including groups of states, FLMs, industry and 
industry representatives, nongovernmental organizations, and others. We 
considered all timely comments submitted on the proposal and address 
many of the most significant comments in this section. We are also 
providing a separate response-to-comments (RTC) document in the docket 
for this rulemaking. Between this preamble and the RTC document, we 
have responded to all significant comments received on this rulemaking.

A. Ongoing Litigation in Texas v. EPA

    A number of state and industry stakeholders submitted comments 
regarding the ongoing litigation in the Fifth Circuit Court of Appeals 
over the EPA's January 2016 final action that partially approved and 
partially disapproved the Oklahoma and Texas regional haze SIPs for the 
first implementation period and promulgated partial FIPs for each 
state.\40\ These commenters asserted that the Fifth Circuit's decision 
granting a stay \41\ of the Texas FIP's reasonable progress emission 
limits undermined our proposed revisions to the visibility regulations. 
Some commenters also suggested that we must suspend our rulemaking 
revising the visibility regulations until after the Fifth Circuit has 
issued a decision on the merits.
---------------------------------------------------------------------------

    \40\ 81 FR 295 (January 5, 2016).
    \41\ Texas v. EPA, 2016 U.S. App. LEXIS 13058 (5th Cir. July 15, 
2016).
---------------------------------------------------------------------------

    We disagree that the Fifth Circuit's recent stay decision in Texas 
v. EPA dictates the lawfulness or timeliness of this rulemaking. First, 
as the commenters have noted, the Fifth Circuit decision was not a 
final decision on the merits of our action on the Oklahoma and Texas 
regional haze SIPs; instead, it was a preliminary decision issued by a 
panel of Fifth Circuit judges reviewing motions to stay the EPA's FIP, 
otherwise referred to as a ``motions panel.'' That panel expressly 
noted that its ``determination of Petitioners' likelihood of success on 
the merits is for the purposes of the stay only and does not bind the 
merits panel.'' \42\ Second, and more importantly, the Fifth Circuit's 
evaluation of the EPA's FIP was based on the existing visibility 
regulations at 40 CFR 51.308(d). In this rulemaking, we are 
promulgating new regulations at 40 CFR 51.308(f) that will govern the 
second and future implementation periods. Under CAA section 307(b), the 
D.C. Circuit Court of Appeals is the exclusive venue for judicial 
review of these regulations. Consequently, the preliminary views of 
another circuit on the lawfulness of a FIP issued in the first 
implementation period under our existing regulations at 40 CFR 
51.308(d) are not germane to this rulemaking. Third, portions of the 
stay decision indicate a fundamental misunderstanding of aspects of the 
visibility program and the EPA's action on the Oklahoma and Texas 
regional haze SIPs. For example, the decision on several occasions 
conflated the BART and reasonable progress requirements of the RHR, 
even though the FIP solely concerned the latter.\43\ Indeed, we 
explicitly delayed final action in promulgating a FIP to address the 
BART requirements for EGUs in Texas in light of the D.C. Circuit's 
decision to remand several of the Cross-State Air Pollution Rule's 
(CSAPR) emissions budgets.\44\
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    \42\ Id. at *42 n.29.
    \43\ See, e.g., id. at *8 (SIPs must ``list the best available 
retrofit technology (`BART') that emission sources in the state will 
have to adopt to achieve the visibility goals''); id. at *9 (``BART 
is the only portion of the implementation plan that is enforced 
against emission sources in a state.''); id. at *42 (asserting that 
``the BART requirements'' are ``the portion of the Final Rule 
imposing injury on Petitioners'').
    \44\ 81 FR 301-02.
---------------------------------------------------------------------------

    While the decision in Texas v. EPA does not dictate the outcome of 
this rulemaking, the decision has created some confusion regarding 
certain aspects of the visibility program, including (1) whether states 
can or must consider the four reasonable progress factors on a source-
specific basis; (2) the scope of the consultation requirements; and (3) 
whether a state's long-term strategy can contain measures that cannot 
be fully implemented by the end of an implementation period. 
Consequently, we believe that it is appropriate to address each of 
these issues at this time to explain how it was treated under the 
existing regulations during the first implementation period and whether 
it will be treated any

[[Page 3088]]

differently (and if so how) under the new regulations governing future 
implementation periods.
1. Source-Specific Analysis
    In Texas v. EPA, the Fifth Circuit explained that neither the RHR 
nor the CAA requires a state to conduct a source-specific four-factor 
analysis.\45\ Several commenters cited this aspect of the Fifth 
Circuit's decision to argue that the EPA's proposal could not require 
states to conduct source-specific four-factor analyses and that, while 
states could conduct such analyses at their discretion, a state's 
decision not to do so could not form the basis of the EPA's disapproval 
of a SIP. Other commenters argued that proposed 40 CFR 51.308(f)(3)(ii) 
would unlawfully force states to conduct source-specific four-factor 
analyses if a state's RPGs provide for a slower rate of improvement in 
visibility than the URP. Several commenters asked us to clarify our 
position on these issues.
---------------------------------------------------------------------------

    \45\ Id. at *45-51.
---------------------------------------------------------------------------

    Neither the 1999 RHR nor the revised regulations in this rulemaking 
require states to conduct four-factor analyses on a source-specific 
basis. CAA section 169A(b)(2) requires states to include in their SIPs 
``emission limits, schedules of compliance and other measures as may be 
necessary to make reasonable progress.'' While these emission limits 
must apply to individual sources or units, section 169A(g)(1) does not 
explicitly require states to consider the four factors on a source-
specific basis when determining what amount of emission reductions (and 
corresponding visibility improvement) constitutes ``reasonable 
progress.'' Unlike section 169A(g)(2), which requires states to 
consider ``any existing control technology in use at the source'' and 
``the remaining useful life of the source'' when determining BART, 
section 169A(g)(1) refers to the four factors more generally. For 
example, with respect to remaining useful life, section 169A(g)(1) 
refers not to ``the source,'' but rather ``any existing source subject 
to such requirements.'' Thus, the EPA has consistently interpreted the 
CAA to provide states with 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. This is the case under the 1999 RHR and 
continues to be the case under these final revisions. Contrary to the 
arguments in some comments, 40 CFR 51.308(f)(3)(ii) explicitly refers 
to ``sources or groups of sources.'' Similarly, 40 CFR 51.308(f)(2)(i) 
also refers to ``major or minor stationary sources or group of sources, 
mobile sources, and area sources.''
    We also note that the stay decision in Texas v. EPA mistakenly 
indicated that the EPA disapproved the Texas SIP for failing to 
evaluate the four factors on a source-specific basis. As we explained 
in the January 2016 final rule, we disapproved Texas's four-factor 
analysis because the set of sources and controls that Texas analyzed 
was both over-inclusive and under-inclusive, not because the state 
failed to conduct a source-specific analysis.\46\ Texas's analysis was 
over-inclusive because it included controls on sources that served only 
to increase total costs with little corresponding visibility benefit, 
and under-inclusive because it did not include scrubber upgrades that 
would achieve highly cost-effective emission reductions that would lead 
to significant visibility improvements. While these final revisions to 
the RHR continue to provide states with considerable flexibility in 
evaluating the four reasonable-progress factors, we expect states to 
exercise reasoned judgment when choosing which sources, groups of 
sources or source categories to analyze. Consistent with CAA section 
169A(g)(1) and our action on the Texas SIP, a state's reasonable 
progress analysis must consider a meaningful set of sources and 
controls that impact visibility. If a state's analysis fails to do so, 
for example, by arbitrarily including costly controls at sources that 
do not meaningfully impact visibility or failing to include cost-
effective controls at sources with significant visibility impacts, then 
the EPA has the authority to disapprove the state's unreasoned analysis 
and promulgate a FIP.
---------------------------------------------------------------------------

    \46\ 81 FR 313-14.
---------------------------------------------------------------------------

2. Interstate Consultation
    In the Texas v. EPA stay decision, the Fifth Circuit explained that 
neither the RHR nor the CAA explicitly require upwind states to provide 
downwind states with source-specific emission control analyses.\47\ 
Consistent with Congress's focus on interstate cooperation under 
section 169B, the 1999 RHR required states to consult with one another 
when developing their RPGs and long-term strategies, develop 
``coordinated emission management strategies'' and document any 
disagreements regarding their goals and strategies.\48\ We agree with 
the Fifth Circuit that the 1999 RHR did not require upwind states to 
provide downwind states with a specific type of four-factor analysis 
during the consultation process; the four-factor analysis that the 
upwind state did could be based on a source-specific or aggregate 
approach, for example. The consultation provisions were intended to 
foster and facilitate regional solutions to what is, by definition, a 
regional problem, not to mandate specific outcomes. The final revisions 
largely preserve the existing consultation provisions and similarly do 
not require upwind states to provide downwind states with any specific 
type of analysis, or vice versa. Nevertheless, to develop coordinated 
emission management strategies, each state must make decisions with 
respect to its own long-term strategy with knowledge of what other 
states are including in their strategies and why. In other words, 
states must exchange their four-factor analyses and the associated 
technical information that was developed in the course of devising 
their long-term strategies. This information includes modeling, 
monitoring and emissions data and cost and feasibility studies. To the 
extent that one state does not provide another other state with these 
analyses and information, or to the extent that the analyses or 
information are materially deficient, the latter state should document 
this fact so that the EPA can assess whether the former state has 
failed to meaningfully comply with the consultation requirements.
---------------------------------------------------------------------------

    \47\ Id. at *51-53.
    \48\ 40 CFR 51.308(d)(1)(iv); (d)(3)(i).
---------------------------------------------------------------------------

3. Timing of Control Requirements
    Lastly, in Texas v. EPA, the Fifth Circuit's stay decision 
suggested that it was likely that the EPA had exceeded its statutory 
authority by imposing emission controls that go into effect after the 
end of the implementation period.\49\ This preliminary assessment is 
incorrect for several reasons.
---------------------------------------------------------------------------

    \49\ Texas, 2016 U.S. App. LEXIS 13058 at *53-57.
---------------------------------------------------------------------------

    First, we note that the decision did not cite to a provision of the 
CAA to support the proposition that the EPA exceeded its statutory 
authority. Indeed, the CAA includes no such constraint. Two provisions 
are of particular relevance. Section 169A(b)(2)(B) requires SIPs to 
include ``a long-term (ten to fifteen years) strategy for making 
reasonable progress toward meeting the national goal.'' The phrase 
``ten to fifteen years'' is ambiguous. It could mean that the long-term 
strategy must be updated every 10 to 15 years or that the strategy must 
be fully implemented within 10 to 15 years. Even under the latter 
interpretation, courts have held that an agency does not lose authority 
to regulate when a mandatory deadline

[[Page 3089]]

has passed; rather, the appropriate remedy is an order compelling 
agency action.\50\ We therefore do not interpret this provision as 
restricting the authority of states or the EPA to include control 
measures in a SIP or FIP that cannot be fully implemented by the end of 
a regulatory implementation period or as relaxing their obligation to 
include such controls if they are otherwise necessary to make 
reasonable progress. To do so would create an inappropriate incentive 
for states to delay their SIP submittals in an effort to ``run out the 
clock'' on the EPA's authority to issue a corrective FIP.
---------------------------------------------------------------------------

    \50\ Oklahoma v. EPA, 723 F.3d 1201, 1223-24 (10th Cir. 2013) 
(citing Brock v. Pierce Cty., 476 U.S. 253, 260 (1986).
---------------------------------------------------------------------------

    Also, section 169A(g)(1) requires states to consider ``the time 
necessary for compliance'' when determining what control measures are 
necessary to make reasonable progress. This phrase is also ambiguous. 
One possible interpretation of the phrase is that states need only 
consider control measures that can be implemented within a certain 
period of time. This interpretation is unreasonable, however, because 
it would allow states to forever forgo cost-effective but time-
intensive emission reduction measures that could otherwise improve 
visibility, which would thwart Congress's national goal. A more 
reasonable interpretation of the phrase is that states must consider 
the feasibility of the ``schedules of compliance'' referred to in 
section 169A(b)(2) when determining when the emission reductions 
necessary to make reasonable progress must be implemented. The 
structure of section 169A also lends support to this interpretation. 
When determining reasonable progress, states must consider three of the 
same factors that they consider when determining BART. The only unique 
reasonable progress factor relates to timing: ``the time necessary for 
compliance.'' Congress had no reason to include a timing factor for 
BART, however, because section 169A(b)(2)(A) already includes a 
requirement that BART must be installed and operated ``as expeditiously 
as practicable,'' which section 169A(g)(4) defines as no later than 5 
years from the date of plan approval. With no similar requirement in 
section 169(b)(2), it is reasonable to interpret that Congress intended 
``the time necessary for compliance'' factor to serve an analogous 
function to the ``expeditiously as practicable'' language, albeit with 
more discretion left to the states.
    Second, we note that the Fifth Circuit appeared to misunderstand a 
provision in the 1999 RHR that it used to support its decision. 
Specifically, the stay decision stated:

    The Regional Haze Rule requires states to ``consider . . . the 
emission reduction measures needed to achieve [the reasonable 
progress goal] for the period covered by the implementation plan,'' 
and to impose ``enforceable emissions limitations, compliance 
schedules, and other measures, as necessary to achieve the 
reasonable progress goals.'' 40 CFR 51.308(d)(1)(i)(B), (d)(3) 
(emphasis added). The Regional Haze Rule provides that each 
implementation plan will cover a ten-year period; before the close 
of each ten-year period, the state must submit a comprehensive 
revision to cover the next ten-year period. 40 CFR 51.308(b), (f) 
(first implementation plan due December 2007; first ``comprehensive 
periodic revision'' due July 31, 2018, and every ten years 
thereafter). The emissions controls included in a state 
implementation plan, therefore, must be those designed to achieve 
the reasonable progress goal for the period covered by the plan. 40 
CFR 51.308(d)(1)(i)(B).\51\
---------------------------------------------------------------------------

    \51\ Texas, 2016 U.S. APP. LEXIS 13058 at *53-54.

However, 40 CFR 51.308(d)(1)(i)(B) does not actually say that states 
must consider the emission reductions measures needed to achieve ``the 
reasonable progress goal'' for the period covered by the implementation 
plan. Instead, it requires states to ``consider the uniform rate of 
improvement in visibility and the emission reduction measures needed to 
achieve it for the period covered by the implementation plan.'' \52\ In 
essence, the provision requires a state to make a comparison between 
its chosen control set and the specific set of control measures that 
would be needed to achieve the URP by the end of the implementation 
period. The provision does not dictate the date by which all of the 
measures in a state's chosen control set must be implemented.
---------------------------------------------------------------------------

    \52\ 40 CFR 51.308(d)(1)(i)(B) (emphases added).
---------------------------------------------------------------------------

    Third, the stay decision did not discuss the EPA's 2007 reasonable 
progress guidance, which specifically recognized that the time needed 
for full implementation of a control measure might extend beyond the 
end of the implementation period. In such situations, the EPA stated 
that it may be appropriate for states to use the time necessary for 
compliance factor ``to adjust the [RPG] to reflect the degree of 
improvement in visibility achievable within the period of the first 
SIP,'' \53\ which would prevent the state from falling short of its 
goal. The 2007 guidance did not state that the CAA or the 1999 RHR 
prohibited states from requiring the control measure.
---------------------------------------------------------------------------

    \53\ Guidance for Setting Reasonable Progress Goals Under the 
Regional Haze Program, revised, at 5-2 (June 1, 2007).
---------------------------------------------------------------------------

    In the proposal for this rulemaking, which was promulgated before 
the Fifth Circuit's stay decision, we did not address this issue. At 
that time, we thought that it was clear that neither states nor the EPA 
lose the authority to require emissions limits or other measures that 
are necessary to make reasonable progress if those limits or measures 
cannot be fully implemented by the end of the implementation period and 
incorporated into the RPGs. For the reasons provided previously, we 
continue to believe that this is the case.
    Therefore, we are modifying 40 CFR 51.308(f)(2)(i) to explicitly 
provide that, when considering the time necessary for compliance, a 
state may not reject a control measure because it cannot be installed 
and become operational until after the end of the implementation 
period. As discussed previously, the state should instead consider that 
fact in determining the appropriate compliance deadline for the 
measure. Of course, any emission reductions that will not occur until 
after the end of the implementation period should not be reflected in 
the RPGs.
    In addition, to avoid any future confusion with respect to this 
issue, we are making a small modification to 40 CFR 51.308(f)(3)(i) in 
these final revisions. This final provision now reads:

    A State in which a mandatory Class I Federal area is located 
must establish reasonable progress goals (expressed in deciviews) 
that reflect the visibility conditions that are projected to be 
achieved by the end of the applicable implementation period as a 
result of those enforceable emissions limitations, compliance 
schedules, and other measures required under paragraph (f)(2) that 
can be fully implemented by the end of the applicable implementation 
period, as well as the implementation of other requirements of the 
CAA.

This modification makes it clear that a state's long-term strategy can 
include emission limits and measures beyond those reflected in the 
state's RPGs. The RPGs are unenforceable tracking metrics. They are not 
meant to dictate or limit the content of a state's long-term strategy 
for making reasonable progress towards Congress's national goal. This 
change is also consistent with our actions promulgating FIPs near the 
end of the first implementation period, which by necessity included 
reasonable progress emission limits with compliance deadlines after 
2018.\54\
---------------------------------------------------------------------------

    \54\ 81 FR 296 (January 5, 2016) (Texas); 81 FR 68319 (October 
4, 2016) (Arkansas).

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[[Page 3090]]

B. Cooperative Federalism

    Some commenters invoked principles of cooperative federalism to 
argue that the proposed revisions were too prescriptive and thus 
undermined the discretion afforded to states by the CAA. As support for 
this argument, the commenters pointed almost exclusively to the Fifth 
Circuit's stay decision in Texas v. EPA, discussed previously, in which 
a motions panel of the Fifth Circuit described EPA's role in reviewing 
SIPs as ``ministerial.'' \55\ Commenters also suggest the proposed 
revisions are inconsistent with the principles announced in American 
Corn Growers Association v. EPA, 291 F.3d 1 (D.C. Cir. 2002) (``Corn 
Growers'').
---------------------------------------------------------------------------

    \55\ Texas, 206 U.S. App. LEXIS 13058 at *5.
---------------------------------------------------------------------------

    As a preliminary matter, the commenters' reliance on Texas v. EPA 
is misplaced. The view expressed in the stay decision, that the EPA has 
only a ``ministerial function'' in reviewing SIPs, is at odds with the 
great majority of courts that have considered this issue in the context 
of the regional haze program. Under the principles of cooperative 
federalism, the CAA vests state air agencies with substantial 
discretion as to how to achieve Congress's air-quality goals and 
standards, but states exercise this authority with federal oversight. 
As the Tenth Circuit explained in Oklahoma v. EPA, ``the EPA reviews 
all SIPs to ensure that they comply with the [CAA],'' and ``[t]he EPA 
may not approve any plan that `would interfere with any applicable 
requirement' of [the Act].'' \56\ Relying on Oklahoma, the Eighth 
Circuit in North Dakota v. EPA held that the ``EPA is left with more 
than the ministerial task of routinely approving SIP submissions,'' 
\57\ and that the ``EPA's review of a SIP extends not only to whether 
the state considered the necessary factors in its determination, but 
also to whether the determination is one that is reasonably moored to 
the CAA's provisions.'' \58\ Similarly, in Arizona v. EPA, the Ninth 
Circuit held that the ``EPA is not limited to the `ministerial' role of 
verifying whether a determination was made; it must `review the 
substantive content of the . . . determination,' '' \59\ and that the 
``EPA has a substantive role in deciding whether state SIPs are 
compliant with the Act and its implementing regulations.'' \60\ In 
accord with these principles, the Third Circuit recently remanded the 
EPA's approval of a state's regional haze SIP where the EPA deferred 
too readily to state conclusions without providing a sufficient 
explanation for overlooking problems in the SIP.\61\ Thus, the view 
expressed by the Fifth Circuit motions panel in the stay decision is an 
outlier.
---------------------------------------------------------------------------

    \56\ Oklahoma v. EPA, 723 F.3d 1201, 1204 (10th Cir. 2013).
    \57\ North Dakota v. EPA, 730 F.3d 750, 761 (8th Cir. 2013).
    \58\ Id. at 766.
    \59\ Ariz. el rel. Darwin v. EPA, 815 F.3d 519, 531 (9th Cir. 
2016).
    \60\ Id. at 532 (emphasis in original).
    \61\ Nat'l Parks Conservation Ass'n v. EPA, 803 F.3d 151, 167 
(3d Cir. 2015).
---------------------------------------------------------------------------

    More importantly, however, the situation in Texas v. EPA is 
inapposite to the situation here. In Texas, we partially disapproved an 
individual state's implementation plan and promulgated a FIP to fill 
the gap. In this rulemaking, we are not expressing views on any state's 
implementation plan, so it is simply premature to suggest that we are 
affording insufficient deference to state choices. Rather, we are 
promulgating revisions to the existing visibility regulations that will 
guide future SIP development. In 1977, Congress expressly required the 
EPA to promulgate regulations ``to assure (A) reasonable progress 
toward meeting the national goal . . . and (B) compliance with the 
requirements of [section 169A].'' \62\ Congress also required the EPA's 
regulations to ``provide guidelines to the States'' \63\ regarding 
``methods for identifying, characterizing, determining, quantifying, 
and measuring visibility impairment;'' \64\ ``modeling techniques for 
determining the extent to which manmade air pollution may reasonably be 
anticipated to cause or contribute to such impairment;'' \65\ and 
``methods for preventing and remedying such manmade air pollution and 
resulting visibility impairment.'' \66\ In 1990, Congress reiterated 
this statutory obligation, tasking the EPA again with carrying out its 
``regulatory responsibilities under [section 169A], including criteria 
for measuring `reasonable progress' toward the national goal.'' \67\
---------------------------------------------------------------------------

    \62\ CAA section 169A(b).
    \63\ CAA section 169A(b)(1).
    \64\ CAA section 169A(a)(3)(A).
    \65\ CAA section 169A(a)(3)(B).
    \66\ CAA section 169A(a)(3)(C).
    \67\ CAA section 169B(e)(1).
---------------------------------------------------------------------------

    These final revisions to the 1999 RHR and 1980 reasonably 
attributable visibility impairment regulations are fully consistent 
with this extensive grant of rulemaking authority. The revisions will 
ensure that the steady environmental progress achieved during the first 
implementation period continues, while streamlining several 
administrative aspects of the program to reduce burdens on states. The 
revisions require states to consider certain factors and provide 
certain information as they develop their regional haze SIPs, but they 
do not mandate specific outcomes. Where applicable, the revisions also 
provide states with significant flexibility to take state-specific 
facts and circumstances into account when developing their long-term 
strategies.\68\ Thus, contrary to the commenters' assertions, the final 
revisions are fully consistent with the CAA's cooperative-federalism 
framework and the decision in Corn Growers, which addressed EPA's 
authority to require states to consider the visibility benefits of BART 
controls in a specific fashion, a set of facts not present in this 
rulemaking, is not on point.
---------------------------------------------------------------------------

    \68\ See, e.g., 81 FR at 26954/1 (explaining that states have 
the flexibility to justify and use values for natural visibility 
conditions that include anthropogenic international emissions).
---------------------------------------------------------------------------

C. Clarifications To Reflect the EPA's Long-Standing Interpretation of 
the Relationship Between Long-Term Strategies and Reasonable Progress 
Goals

1. Summary of Proposal
    Under the 1999 RHR, states were required to revise their regional 
haze SIPs every 10 years by evaluating and reassessing all of the 
elements required under 40 CFR 51.308(d).\69\ Over the course of the 
first implementation period, however, we realized that some of the 
requirements in 40 CFR 51.308(d) were creating confusion regarding the 
relationship between RPGs and the long-term strategy and the respective 
obligations of upwind and downwind states. We discussed this issue at 
length in our December 14, 2014, proposed action on the Texas and 
Oklahoma regional haze SIPs,\70\ and incorporated that discussion by 
reference in the proposal for this rulemaking.\71\
---------------------------------------------------------------------------

    \69\ 40 CFR 51.308(f).
    \70\ 79 FR 74823-30 (December 14, 2014).
    \71\ 81 FR 26949, 26952.
---------------------------------------------------------------------------

    For example, under 40 CFR 51.308(d), states were required to (1) 
develop RPGs, (2) calculate baseline and natural visibility conditions, 
(3) establish long-term strategies and (4) adopt monitoring strategies 
and other measures to track future progress and ensure compliance. The 
sequencing of these requirements in the rule text was problematic 
because it did not accord with the way the planning process works in 
practice. For example, states must calculate baseline and natural 
visibility conditions before they can compare their RPGs to the URP. 
Similarly, states must evaluate the control measures that are necessary 
to

[[Page 3091]]

make reasonable progress using the four factors and develop their long-
term strategies before they can predict future emission reductions and 
conduct the regional-scale modeling used to establish RPGs.
    Similarly, problematic was the confusing way in which 40 CFR 
51.308(d) addressed the obligations of upwind and downwind states. 
Under 40 CFR 51.308(d)(1)(i)(A), downwind states were explicitly 
required to consider the four factors when developing their RPGs. 
Upwind states, on the other hand, were implicitly required to consider 
the four factors only when developing their long-term strategies. 
Section 40 CFR 51.308(d)(3)(iii) required states to ``document the 
technical basis, including modeling, monitoring and emissions 
information, on which the State is relying to determine its 
apportionment of emission reduction obligations necessary for achieving 
reasonable progress in each mandatory Class I Federal area it 
affects.'' As we explained in our December 14, 2014, proposed action on 
the Texas and Oklahoma regional haze SIPs, the CAA requires states to 
determine reasonable progress by considering the four factors, so the 
determination of the proper apportionment of emission reductions 
necessarily required a state to evaluate the four factors in reaching 
its decision. This structure made little sense because both upwind and 
downwind states need to conduct their four-factor analyses, determine 
the proper apportionment of emission reduction obligations, and develop 
their long-term strategies before the downwind state will have 
sufficient information to establish RPGs.
    Recognizing that the sequence and structure of the existing 
regulations was confusing, we proposed to amend 40 CFR 51.308(f), which 
governs periodic SIP revisions for future implementation periods, to 
codify our long-standing interpretation of the way in which the 
existing regulations were intended to operate. Specifically, we 
proposed to eliminate the cross-reference in 40 CFR 51.308(f) to 40 CFR 
51.308(d) and to adopt new regulatory language that tracked the actual 
planning sequence, while clarifying the obligations of upwind and 
downwind states.\72\ Under the proposal, states would (1) calculate 
baseline, current and natural visibility conditions, progress to date 
and the URP; (2) develop a long-term strategy for addressing regional 
haze by evaluating the four factors to determine what emission limits 
and other measures are necessary to make reasonable progress; (3) 
conduct regional-scale modeling of projected future emissions under the 
long-term strategies to establish RPGs and then compare those goals to 
the URP line; \73\ and (4) adopt a monitoring strategy and other 
measures to track future progress and ensure compliance.
---------------------------------------------------------------------------

    \72\ 81 FR 26952.
    \73\ This step applies only to downwind states that have 
mandatory Class I Federal areas.
---------------------------------------------------------------------------

2. Comments and Responses
    In response to our proposed structural revisions to 40 CFR 
51.308(f), we received a number of significant comments. Some 
commenters contended that the proposed revisions were contrary to the 
structure and plain language of the CAA. They explained the position 
that states must first make a ``determination'' as to what constitutes 
``reasonable progress'' by analyzing the four statutory factors on a 
source-category basis. Then, only after ``reasonable progress'' is 
quantified as a benchmark or goal do states have to consider what 
emission limits, schedules of compliance and other measures at 
individual sources are actually necessary to make reasonable progress. 
The commenters further explained that this reading of the statute was 
supported by the current regulations, the preamble to the 1999 RHR and 
the EPA's prior guidance. Based on their reading, these commenters 
concluded that proposed 40 CFR 51.308(f)(2), which would govern long-
term strategies, and proposed 40 CFR 51.308(f)(3), which would govern 
RPGs, were contrary to the CAA because states must first determine 
reasonable progress independently from the development of the long-term 
strategy, not the other way around.
    We disagree. Our proposed structural revisions to 40 CFR 51.308(f) 
are consistent with the CAA. Section 169A(b)(2) requires states to 
submit SIP revisions that contain ``emission limits, schedules of 
compliance and other measures as necessary to make reasonable progress 
toward meeting the national goal'' and ``a long-term (ten to fifteen 
years) strategy for making reasonable progress.'' Section 169A(g)(1) 
states that, in determining reasonable progress, states must consider 
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.'' Under 40 CFR 51.308(f)(2), both as 
proposed and as we are finalizing it, states must similarly submit a 
``long-term strategy'' that includes ``enforceable emissions 
limitations, compliance schedules, and other measures that are 
necessary to make reasonable progress,'' and determine those limits, 
schedules, and measures by considering the four statutory factors.
    We disagree that the CAA requires EPA's regulations to allow states 
to calculate the visibility improvement that represents ``reasonable 
progress'' prior to or independently from the analysis of control 
measures. The commenters do not explain how states could consider 
costs, time schedules, energy and environmental impacts or the 
remaining useful lives of sources other than by assessing the potential 
impacts of control measures on those sources. Indeed, 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. 
Moreover, the reasonable progress factors share obvious similarities 
with the BART factors, which are indisputably used to determine 
appropriate control measures for sources.\74\
---------------------------------------------------------------------------

    \74\ Compare CAA section 169A(g)(1) with CAA section 169A(g)(2).
---------------------------------------------------------------------------

    Finally, we note that RPGs are not a concept that is included in 
the CAA itself. Rather, they are a regulatory construct that we 
developed to satisfy a separate statutory mandate in section 
169B(e)(1), which required our regulations to include ``criteria for 
measuring `reasonable progress' toward the national goal.'' \75\ Under 
40 CFR 51.308(f)(3)(ii), RPGs continue to serve this important 
analytical function. They measure the progress that is projected to be 
achieved by the control measures states have determined are necessary 
to make reasonable progress based on a four-factor analysis. Consistent 
with the 1999 RHR, the RPGs are unenforceable,\76\ but they create a 
benchmark that allows for analytical

[[Page 3092]]

comparisons to the URP \77\ and mid-implementation-period course 
corrections if necessary.\78\
---------------------------------------------------------------------------

    \75\ See 64 FR 35731 (``The final rule calls for States to 
establish `reasonable progress goals,' expressed in deciviews, for 
each Class I area for the purpose of improving visibility on the 
haziest days and not allowing degradation on the clearest days over 
the period of each implementation plan or revision. The EPA believes 
that requiring States to establish such goals is consistent with 
section 169A of the CAA, which gives EPA broad authority to 
establish regulations to `ensure reasonable progress,' and with 
section 169B of the CAA, which calls for EPA to establish `criteria 
for measuring reasonable progress' toward the national goal.'').
    \76\ Compare 40 CFR 51.308(f)(3)(iii) with 40 CFR 51.308(d)(v).
    \77\ Compare 40 CFR 51.308(f)(3)(ii) with 40 CFR 
51.308(d)(1)(ii).
    \78\ 40 CFR 51.308(g)(7), (h).
---------------------------------------------------------------------------

    Other commenters stated that the proposed revisions to 40 CFR 
51.308(f) were significant and unexplained departures from the EPA's 
prevailing interpretation of the reasonable progress factors and long-
term strategy during the first implementation period. Several 
commenters contended that the revisions constituted an arbitrary and 
capricious change of position under the Supreme Court's recent decision 
in Encino Motorcars, LLC v. Navarro, 136 S. Ct. 2117 (2016). For 
example, one commenter contended that it was paradoxical for the long-
term strategy to include the measures necessary to achieve the RPGs, 
while the RPGs were the predicted visibility outcome of implementing 
the emission controls in the long-term strategy. The commenter 
explained that this was inconsistent with the 1999 RHR, which made no 
mention of RPGs being set based on the predicted visibility improvement 
resulting from emission controls.
    Another commenter contended that the EPA's proposed approach puts 
the cart before the horse because it does not allow states and RPOs to 
set visibility targets and then select the appropriate emission 
reduction measures to reach those targets. This would result in 
inefficiencies, according to the commenter, because states may have to 
secure additional emission reductions if their chosen strategies result 
in RPGs that fall short of the URP. The commenter explained that states 
would need more guidance regarding what types of sources and source 
categories to consider when seeking emission reductions. The commenter 
requested that the EPA develop a more logical process whereby states 
and RPOs would first develop visibility goals, allocate those goals 
among the states and then give states latitude to identify and assure 
emission reductions to achieve those visibility goals by using the four 
factors.
    We disagree with these comments. They reflect a misunderstanding of 
the regional haze planning process generally followed by states. During 
the first implementation period, the RPOs conducted the regional-scale 
modeling used to establish their member states' RPGs. To conduct this 
modeling, the RPOs relied on 2018 emissions projections that reflected 
future application of reasonable controls for sources, including 
existing federal and state measures (the Clean Air Interstate Rule 
(CAIR), mobile source measures, etc.), anticipated BART controls and 
anticipated reasonable progress measures. The proposed and final 
revisions to 40 CFR 51.308(f) are fully consistent with this process. 
Under 40 CFR 51.308(f)(ii), states must develop their long-term 
strategies by identifying reasonable progress measures using the four 
factors and engaging in interstate consultation. Once their strategies 
have been developed, states with Class I areas must establish RPGs that 
reflect existing federal and state measures (the CSAPR, the Mercury and 
Air Toxics Standards, BART, mobile source measures, etc.) and the 
reasonable progress measures in the long-term strategy.
    In contrast, the commenters have proposed a process in which states 
would either model their RPGs without fully developed emissions 
information or select their goals arbitrarily without any modeling at 
all. We rejected a similar approach in the 1999 RHR. In the 1997 
proposal for the RHR, we proposed to establish presumptive reasonable 
progress targets of 1.0 deciview of improvement for the most impaired 
days and no degradation for the least impaired days and to require 
states to develop emission reduction strategies to achieve the 
reasonable progress targets.\79\ In the 1999 RHR, we revised the 
proposal to eliminate the presumptive targets and instead required 
states ``to determine the rate of progress for remedying existing 
impairment that is reasonable, taking into consideration the statutory 
factors.'' \80\ Importantly, we explained that, ``[i]n considering 
whether reasonable progress will continue to be maintained, States will 
need to consider during each new SIP revision cycle whether additional 
control measures for improving visibility may be needed to make 
reasonable progress based on the statutory factors.'' \81\ Thus, the 
1999 RHR was clear that states must determine what control measures are 
necessary to make reasonable progress by considering the four factors 
and then use this information to determine the rate of progress that is 
reasonable for each mandatory Class I Federal area.
---------------------------------------------------------------------------

    \79\ 62 FR 41146-47 (July 31, 1997).
    \80\ 64 FR 35731 (July 1, 1999).
    \81\ Id. at 35733.
---------------------------------------------------------------------------

    In 2007, we provided guidance to the states on setting RPGs. There, 
we explained that the guidance's discussion of the four factors was 
``largely aimed at helping States apply these factors in considering 
measures for point sources,'' \82\ but that the factors could 
potentially be applied to sources other than point sources as well. We 
also described the intricate relationship between RPGs, BART, and the 
long-term strategy:
---------------------------------------------------------------------------

    \82\ Guidance for Setting Reasonable Progress Goals Under the 
Regional Haze Program, at 1-3 (2007) (emphasis added).

    The RPGs, the long-term strategy, and BART (or alternative 
measures in lieu of BART) are the three main elements of the 
regional haze SIPs that States are required to submit by December 
17, 2007. The long-term strategy and BART emissions limitations or 
other alternative measures, including cap-and-trade programs or 
other economic incentive approaches, are inherently related to the 
RPG. The long-term strategy is the compilation of ``enforceable 
emissions limitations, compliance schedules, and other measures as 
necessary to achieve the [RPGs],'' and is the means through which 
the State ensures that its RPG will be met. BART emissions limits 
(or alternative measures in lieu of BART, such as the Clean Air 
Interstate Rule (CAIR)) are one set of measures that must be 
included in the SIP to ensure that an area makes reasonable progress 
toward the national goal, and the visibility improvement resulting 
from BART (or a BART alternative) is included in the development of 
the RPG.\83\
---------------------------------------------------------------------------

    \83\ Id. at 1-4.

    We note that the discussion previously refers to the long-term 
strategy as including the measures ``necessary to achieve the RPG,'' 
and that several provisions in the 1999 RHR were worded similarly.\84\ 
We believe this type of language may have caused confusion among some 
of the commenters. This language does not mean that we intended states 
to develop their RPGs first and later adopt measures in the long-term 
strategy to achieve those RPGs. Rather, it merely acknowledges the fact 
that, because we intended states to develop their RPGs by modeling, 
among other things, the measures in the long-term strategy, the 
measures in the strategy are necessary to achieve the RPGs. For 
example, BART is one of the measures in the long-term strategy, and the 
discussion previously clearly states that ``the visibility improvement 
resulting from BART (or a BART alternative) is included in the 
development of the RPG.'' We proposed the structural revisions to 40 
CFR 51.308(f) in part to eliminate this cart-before-the-horse 
ambiguity.
---------------------------------------------------------------------------

    \84\ See, e.g., 40 CFR 51.308(d)(3), (d)(3)(ii), (d)(3)(v)(C).
---------------------------------------------------------------------------

    Later, the 2007 guidance clearly describes the goal-setting process 
as starting with the evaluation of control measures. First, we 
recommended that states ``[i]dentify the key pollutants and sources 
and/or source categories that are contributing to visibility impairment 
at

[[Page 3093]]

each Class I area.'' \85\ Second, we recommended that states 
``[i]dentify the control measures and associated emission reductions 
that are expected to result from compliance with existing rules and 
other available measures for the sources and source categories that 
contribute significantly to visibility impairment.'' \86\ Third, and 
most importantly, we recommended that states ``[d]etermine what 
additional control measures would be reasonable based on the statutory 
factors and other relevant factors for the sources and/or source 
categories you have identified.'' \87\ Finally, we recommended that 
states ``[e]stimate through the use of air quality models the 
improvement in visibility that would result from implementation of the 
control measures you have found to be reasonable and compare this to 
the uniform rate of progress.'' \88\ In sum, ``[t]he improvement in 
visibility resulting from implementation of the measures you have found 
to be reasonable . . . is the amount of progress that represents your 
RPG.'' \89\ This is the process that states used during the first 
implementation period, see the RTC at 2.2.1.2.6 for examples, and it is 
the same process that the states must follow under the final revisions 
to 40 CFR 51.308(f).
---------------------------------------------------------------------------

    \85\ Id. at 203.
    \86\ Id. (emphasis in the original).
    \87\ Id.
    \88\ Id.
    \89\ Id. at 2-4 (emphasis added).
---------------------------------------------------------------------------

    While the guidance went on to note that states could attempt to 
``back out'' the measures necessary to achieve the URP by modeling 
first and then considering the four factors to select appropriate 
measures,\90\ few if any states chose this approach, likely because it 
was a more complicated way to achieve the same result as the 
recommended approach. Under either approach, states still had to use 
the four factors to justify whether the control measures necessary to 
achieve the URP were reasonable, whether achieving the URP was 
unreasonable and some of lesser set of measures was reasonable, or 
whether additional measures were reasonable. Moreover, the ``back out'' 
approach specified a concrete visibility target as its basis: The 
visibility that would be achieved by the URP at the end of the 
implementation period. The approach would be arbitrary and unworkable 
as a step in making the justifications just mentioned if the visibility 
target were chosen at random, as some commenters have requested. In 
sum, the EPA's proposed structural revisions are completely consistent 
with the 1999 RHR, our 2007 guidance and the planning process actually 
used by states during the first implementation period. For this reason, 
the Supreme Court's decision in Encino Motorcars is inapplicable.
---------------------------------------------------------------------------

    \90\ Id. at 2-3 to 2-4.
---------------------------------------------------------------------------

    Another commenter contended that the EPA's proposed revisions 
failed to include a necessary step where states evaluate the control 
measures identified as necessary to make reasonable progress in light 
of the RPGs themselves. This commenter requested a mechanism whereby a 
state could determine that some of the initially evaluated control 
measures were unnecessary in light of the RPGs themselves. In 
particular, this commenter suggested that a state should be able to 
reject ``costly'' control measures if (1) the RPG for the most impaired 
days is on or below the URP line or (2) the RPGs are not 
``meaningfully'' different than current visibility conditions.
    We disagree that the states should be able to reevaluate whether a 
control measure is necessary to make reasonable progress based on the 
RPGs. The CAA requires states to determine what emission limitations, 
compliance schedules and other measures are necessary to make 
reasonable progress by considering the four factors. The CAA does not 
provide that states may then reject some control measures already 
determined to be reasonable if, in the aggregate, the controls are 
projected to result in too much or too little progress. Rather, the 
rate of progress that will be achieved by the emission reductions 
resulting from all reasonable control measures is, by definition, a 
reasonable rate of progress.
    In regards to the commenter's first suggestion, if a state has 
reasonably selected a set of sources for analysis and has reasonably 
considered the four factors in determining what additional control 
measures are necessary to make reasonable progress, then the state's 
analytical obligations are complete if the resulting RPG for the most 
impaired days is below the URP line. The URP is not a safe harbor, 
however, and states may not subsequently reject control measures that 
they have already determined are reasonable. If a state's RPG for the 
most impaired days is above the URP line, then the state has an 
additional analytical obligation to ensure that no reasonable controls 
were left off the table.
    The commenter's second suggestion, that states should be able to 
reject ``costly'' control measures if the RPG for the most impaired 
days is not ``meaningfully'' different than current visibility 
conditions, is counterintuitive and at odds with the purpose of the 
visibility program. In this situation, the state should take a second 
look to see whether more effective controls or additional measures are 
available and reasonable. Whether the state takes this second look or 
not, it may not abandon the controls it has already determined are 
reasonable based on the four factors. Regional haze is visibility 
impairment that is caused by the emission of air pollutants from 
numerous sources located over a wide geographic area. At any given 
Class I area, hundreds or even thousands of individual sources may 
contribute to regional haze. Thus, it would not be appropriate for a 
state to reject a control measure (or measures) because its effect on 
the RPG is subjectively assessed as not ``meaningful.'' Also, for Class 
I areas where visibility conditions are considerably worse than natural 
conditions because of continuing anthropogenic impairment from numerous 
sources, the logarithmic nature of the deciview index makes the effect 
of a control measure on the value of the RPG less than its effect would 
be if visibility conditions at the Class I area were better. Thus, if a 
state could reject a control measure based on its individual effect on 
the RPG, the state would be more likely to reject those measures that 
are necessary to make reasonable progress at the dirtiest Class I 
areas, which would thwart Congress' national goal.
    One commenter contended that the proposed revisions would lead to 
disagreements among states because states might set different RPGs 
instead of working jointly toward the downwind state's goals. We 
disagree. Only downwind states set RPGs for their mandatory Class I 
Federal areas, so there is no situation in which there would be 
different goals for the same area.
    Another commenter contended that the proposed revisions would force 
states to require controls even where visibility at a Class I area is 
already equivalent to or better than the visibility that represents the 
URP at the end of the implementation period. We agree that some states 
may end up establishing RPGs that exceed the URP, but as we explained 
previously in this document, the URP was never intended to be a safe 
harbor. In the 1999 RHR, we explained that ``[i]f the State determines 
that the amount of progress identified through the analysis is 
reasonable based upon the statutory factors, the State should identify 
this amount of progress as its reasonable progress goal for the first 
long-term strategy, unless it determines that additional progress 
beyond this

[[Page 3094]]

amount is also reasonable. If the State determines that additional 
progress is reasonable based on the statutory factors, the State should 
adopt that amount of progress as its goal for the first long-term 
strategy.'' \91\ This approach is consistent with and advances the 
ultimate goal of section 169A: Remedying existing and preventing future 
visibility impairment. Congress required the EPA to promulgate 
regulations requiring reasonable progress toward that goal, and it 
would be antithetical to allow states to avoid implementing reasonable 
measures until and unless that goal is achieved.
---------------------------------------------------------------------------

    \91\ 64 FR 35732.
---------------------------------------------------------------------------

    Other commenters were supportive of the proposed structural 
revisions intended to clarify the relationship between RPGs and long-
term strategies. They explained that by reorienting these provisions to 
reflect the EPA's long-standing interpretation, the EPA was providing a 
clearer blueprint for states to follow in future implementation 
periods. These commenters also provided specific suggestions for how 
the EPA could further revise the proposed regulatory text for 40 CFR 
51.308(f). Among other things, these commenters requested that the EPA 
include language in the regulations that would make it clear that a 
state's long-term strategy can include emission limits and other 
measures that cannot be installed by the end of an implementation 
period. As discussed earlier in Section IV.A of this document, we are 
modifying the language in 40 CFR 51.308(f)(2(i) and 51.308(f)(3)(i) to 
make this point clear. We have reviewed the other suggestions made by 
these commenters and do not believe that they are necessary, as 
discussed more fully in the RTC document available in the docket for 
this rulemaking.
    We also received several comments regarding the obligations of 
upwind and downwind states. Some commenters supported the revisions 
that were intended to clarify that all states must conduct a four-
factor analysis to determine what control measures are necessary to 
make reasonable progress at each mandatory Class I Federal area 
affected by emissions from the state. They explained that any other 
interpretation of the CAA's requirements would allow an upwind state to 
continue impairing downwind visibility without consequence, regardless 
of whether there were reasonable, cost-effective measures that would 
improve downwind visibility. Other commenters argued that upwind states 
should not have the same obligations as downwind states. One commenter 
asserted that, under the proposal, all states would be subject to the 
RHR for the very first time, regardless of whether they have a 
mandatory Class I Federal area or not. Another commenter contended that 
requiring upwind states to conduct four-factor analyses for downwind 
Class I areas was a new requirement that was not part of the 1999 RHR. 
This commenter acknowledged that upwind states must address downwind 
Class I areas where their emissions ``may reasonably be anticipated to 
cause or contribute to any impairment of visibility'' at the downwind 
area, but suggested that the proposed revisions use the language ``may 
affect'' instead. This commenter stated that the EPA's proposal did not 
define or quantify what the term ``may affect'' means.

    Section 169A(b)(2) states that the EPA's regulations must: 
Require each applicable implementation plan for a State in which any 
[mandatory Class I Federal] area . . . is located (or a for a State 
the emissions from which may reasonably be anticipated to cause or 
contribute to any impairment of visibility in any such area) to 
contain such emission limits, schedules of compliance and other 
measures as may be necessary to make reasonable progress toward 
meeting the national goal.

Section 169A(g)(1) thus requires states to determine the measures 
necessary to make reasonable progress by considering the four factors, 
while section 169A(a)(1) defines Congress's national goal as preventing 
future and remedying existing anthropogenic visibility impairment in 
all Class I areas. Thus, Congress was clear that both downwind states 
(i.e., ``a State in which any [mandatory Class I Federal] area . . . is 
located) and upwind states (i.e., ``a State the emissions from which 
may reasonably be anticipated to cause or contribute to any impairment 
of visibility in any such area'') must revise their SIPs to include 
measures that will make reasonable progress at all affected Class I 
areas. Congress was also clear that states must determine the necessary 
measures and rate of progress that are reasonable by considering the 
four factors. Our proposed revisions to 40 CFR 51.308(f)(2) are in 
accord with this congressional mandate.
    The commenter who suggested that our proposed revisions are 
expanding the scope of the RHR to all states for the first time is 
incorrect. The 1999 RHR applies to all states,\92\ and all states 
submitted regional haze SIPs (or asked the EPA to promulgate a regional 
haze FIP on its behalf) during the first implementation period. As 
discussed later in this preamble, we are expanding the scope of the 
1980 reasonably attributable visibility impairment regulations to all 
states for the first time, but the new reasonably attributable 
visibility impairment provisions only require state action upon receipt 
of a certification by a FLM. Historically, there have been very few FLM 
certifications requesting states to assess controls for a particular 
source or small group of sources.
---------------------------------------------------------------------------

    \92\ 40 CFR 51.300(b)(1)(i).
---------------------------------------------------------------------------

    Finally, we note that the language ``may affect'' in 40 CFR 
51.308(f)(2) was adapted from the 1999 RHR, which used the same 
term.\93\ On July 8, 2016, we released draft guidance that discusses 
how states can determine which Class I areas they ``may affect'' and 
therefore must consider when selecting sources for inclusion in a four-
factor analysis.\94\ The draft guidance discusses various approaches 
that states used during the first implementation period, provides 
states with the flexibility to choose from among these approaches in 
the second implementation period, and recommends that states adopt ``a 
conservative . . . approach to determining whether their sources may 
affect visibility at out-of-state Class I areas.'' \95\ We plan to 
finalize the draft guidance in the near future.
---------------------------------------------------------------------------

    \93\ See 40 CFR 51.308(d)(3).
    \94\ 81 FR 44608 (July 8, 2016).
    \95\ Draft Guidance on Progress Tracking Metrics, Long-term 
Strategies, Reasonable Progress Goals and Other Requirements for 
Regional Haze State Implementation Plans for the Second 
Implementation Period, at 57-58 (2016).
---------------------------------------------------------------------------

    We also received comments on the proposed interstate consultation 
provisions in 40 CFR 51.308(f). A few commenters inquired whether 
proposed 40 CFR 51.308(f)(2)(iii) \96\ would affect a substantive 
change from the existing consultation provisions in 40 CFR 51.308(d). 
One commenter stated that proposed 40 CFR 51.308(f)(2)(ii) would 
apparently require states to consider how other states calculated the 
URP, adopted emission reduction measures for sources and adopted any 
additional measures that may be needed to address state contributions. 
This commenter also argued that proposed 40 CFR 51.308(f)(2)(iii) would 
incentivize states not to agree with other states on coordinated 
emission management strategies because an agreement would create an 
enforceable obligation against the state. Another commenter stated that 
the EPA would need to coordinate and

[[Page 3095]]

mediate interstate consultations in order for them to prove successful.
---------------------------------------------------------------------------

    \96\ As explained later in this document, the final rule 
includes a consolidation and resulting renumbering of some of the 
proposed provisions of 40 CFR 51.308(f)(2). This discussion refers 
specifically to either proposed or final section numbers to avoid 
confusion.
---------------------------------------------------------------------------

    With one exception, we did not intend the proposed interstate 
consultation provisions to affect a substantive change from the 
existing provisions in the 1999 RHR. Under the proposed provisions, as 
under the 1999 RHR, states must consult to develop coordinated emission 
management strategies, demonstrate that their SIPs contain all agreed-
upon emission reduction measures, and document disagreements so that 
the EPA can properly evaluate whether each state's implementation plan 
provides for reasonable progress toward the national goal. We also 
proposed a new requirement, in 40 CFR 51.308(f)(2)(ii), that states 
must consider the control strategies being adopted by other states when 
conducting their own four-factor analyses. The purpose of this 
provision was to ensure that if one state had identified a control 
measure as being reasonable for a source or group of sources to improve 
visibility at a Class I area, then other states that affect that Class 
I area would be required to consider that control measure for their own 
sources, to the extent that the sources share similar characteristics. 
However, in reviewing proposed 40 CFR 51.308(f)(2)(ii), we realized 
that it contains extraneous language that has led to confusion among 
some of the commenters. We discuss this issue in more depth, and other 
changes being made to the consultation provisions, in the following 
section.
    In regard to the commenter's concern that the consultation 
provisions will incentivize states to avoid entering into agreements 
with each other to avoid enforceable obligations, we disagree. States 
largely worked cooperatively to develop coordinated emission management 
strategies during the first implementation period, and we expect that 
they will do so again. If a state believes that additional controls 
from sources in another state or states are necessary to make 
reasonable progress at a Class I area, then the state should document 
the disagreement to assist the EPA in determining whether the other 
state's SIP is inadequate. Moreover, even if states were to avoid 
entering into agreements for the purpose of avoiding enforceable 
obligations under 40 CFR 51.308(f)(iii), this would not absolve the 
states of their independent obligation to include in their SIPs 
enforceable emission limits and other measures that are necessary to 
make reasonable progress at all affected Class I areas, as determined 
by considering the four factors. Finally, we do not believe that the 
EPA needs to coordinate or mediate interstate consultations. During the 
first implementation period, states consulted one-on-one and through 
the RPO process without EPA oversight, and we expect this process to 
work going forward as well.
3. Final Rule
    We are finalizing the revisions to 40 CFR 51.308(f) that were 
intended to clarify the relationship between RPGs and long-term 
strategies and the obligations of upwind and downwind states largely as 
proposed. However, we are making several changes to the provisions in 
40 CFR 51.308(f)(2) governing long-term strategies to simplify these 
provisions, enhance clarity and eliminate superfluous regulatory text.
    In 40 CFR 51.308(f)(2), we are revising the requirement that states 
must include in their long-term strategies ``the enforceable emissions 
limitations, compliance schedules, and other measures that are 
necessary to achieve reasonable progress'' to read ``make reasonable 
progress'' instead. This change is to maintain consistency with the 
language in CAA section 169A(b)(2).
    In 40 CFR 51.308(f)(2)(i), we are making two minor changes. First, 
we are revising the beginning of the first sentence to read, ``[t]he 
State must evaluate and determine the emission reduction measures that 
are necessary to make reasonable progress by considering'' the four 
factors. We believe that this formulation is clearer than the language 
in the proposal and more consistent with the language of the CAA. 
Second, we are revising the second sentence, and splitting it into two 
separate sentences, to make it clear that states must consider 
anthropogenic sources of visibility impairment when conducting their 
four-factor analyses, not natural sources, and that anthropogenic 
sources can include mobile and area sources in addition to major and 
minor stationary sources. As mentioned earlier, we are also adding a 
sentence to 40 CFR 51.308(f)(2)(i) regarding the consideration of 
emission controls that cannot reasonably be installed prior to the end 
of the implementation period.
    We are removing proposed 40 CFR 51.308(f)(2)(ii) in these final 
revisions, which required states to consider the URP, the emission 
reduction measures identified under 40 CFR 51.308(f)(2)(i), and 
measures being adopted by contributing states under 40 CFR 
51.308(f)(2)(iii) when developing their long-term strategies. States 
are already required to consider the URP under 40 CFR 51.308(f)(3)(ii) 
when establishing their RPGs. Moreover, it is duplicative to require 
states to consider the emission reduction measures identified under 40 
CFR 51.308(f)(2)(i) a second time. As discussed in the following 
paragraph, we are moving the third requirement in proposed 40 CFR 
51.308(f)(2)(ii) to the interstate consultation provisions.
    We are changing proposed 40 CFR 51.308(f)(2)(iii), regarding 
interstate consultations, to be 40 CFR 51.308(f)(2)(ii) and making 
several changes. First, we are removing the distinction between 
contributing states and states affected by contributing states because 
the substance of the two provisions was essentially the same. The final 
revisions include a single provision requiring each state to consult 
with the other states that are reasonably anticipated to contribute to 
visibility impairment in a mandatory Class I Federal area to develop 
coordinated emission management strategies. Identification of the other 
states should occur as part of a regional planning process. Second, we 
are revising the language that required states to obtain either their 
``share of the emission reductions needed to provide for reasonable 
progress'' or ``all measures needed to achieve its apportionment of 
emission reduction obligations'' depending on whether the state was a 
contributing state or a state affected by contributing states. Most 
states are both contributing states and states affected by contributing 
states, so these variations in wording could be viewed as creating two 
distinct obligations. Now, each state must demonstrate that it has 
included in its long-term strategy ``all measures agreed to during 
state-to-state consultations or a regional planning process, or 
measures that will provide equivalent visibility improvement.'' Third, 
as discussed previously, we have moved the requirement that states 
consider the emission reduction measures other states have identified 
as being necessary to make reasonable progress from proposed 40 CFR 
51.308(f)(2)(ii), which accordingly has been eliminated, to the 
interstate consultation provisions (now numbered as 40 CFR 
51.308(f)(2)(ii)) because it is a more logical place for it. We have 
also revised the wording of this provision to eliminate the ambiguity 
in the proposed language noted by commenters regarding ``additional 
measures being adopted'' by other states. Under this provision, states 
must consider whether the emission reduction measures other states have 
identified by other States for their sources as being necessary to make 
reasonable progress in the mandatory Class I Federal area. This 
consideration

[[Page 3096]]

is appropriate especially when the sources are of a similar type and 
have similar emissions profiles and visibility impacts.
    We are changing proposed 40 CFR 51.308(f)(2)(iv), regarding 
documentation requirements, to be 40 CFR 51.308(f)(2)(iii) and making a 
few minor changes. First, we are revising the first sentence to require 
the states 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 area it 
affects.'' The proposed language referred to ``information on the 
factors listed in (f)(2)(i) and modeling, monitoring, and emissions 
information,'' but we believe this language was confusing because it 
suggested that information on the four factors was something distinct 
from modeling, monitoring and emissions information. The purpose of 
this provision is to require states to document all of the information 
on which they rely to develop their long-term strategies, which will 
primarily be information used to conduct the four-factor analysis. 
Therefore, in addition to modeling, monitoring and emissions 
information, we are making it explicit that states must also submit the 
cost and engineering information on which they are relying to evaluate 
the costs of compliance, the time necessary for compliance, the energy 
and non-air quality impacts of compliance and the remaining useful 
lives of sources.
    We are removing proposed 40 CFR 51.308(f)(2)(v), which required 
states to identify the anthropogenic sources of visibility impairment 
analyzed using the four factors and the criteria used to select sources 
for analysis, because 40 CFR 51.308(f)(2)(i) as finalized already 
includes these requirements.
    Finally, we are changing proposed 40 CFR 51.308(f)(2)(vi) to be 40 
CFR 51.308(f)(2)(iv) and making a few changes. We are revising the 
first sentence of this provision to clarify that the enumerated factors 
are additional to the factors states must consider in 40 CFR 
51.308(f)(2)(i). We are also removing proposed 40 CFR 
51.308(f)(2)(vi)(C) and (F) because they are duplicative requirements. 
These provisions required states to consider the emission limitations 
and schedules for compliance to achieve the RPG and the enforceability 
of emission limitations and control measures. Section 40 CFR 
51.308(f)(2) already requires states to include enforceable emission 
limitations, compliance schedules, and other measures that are 
necessary to make reasonable progress in their long-term strategies. 
Section IV.G of this document discusses revisions we are making to the 
additional factor regarding basic smoke management practices and smoke 
management programs.

D. Other Clarifications and Changes to Requirements for Periodic 
Comprehensive Revisions of Implementation Plans

    The following clarifications and changes were also proposed to be 
included in the revised 40 CFR 51.308(f). A summary of each proposed 
clarifying change, a synopsis of the final rule, and a discussion of 
comments received and EPA's responses are given later.
    The URP line starts at 2000-2004, for every implementation period.
1. Summary of Proposal
    The 1999 RHR's text of 40 CFR 51.308(d)(1)(i)(B) contains a 
discussion of how states must analyze and determine ``the rate of 
progress needed to attain natural visibility conditions by the year 
2064.'' This rate has commonly been called the ``uniform rate of 
progress'' or URP as well as ``the glidepath.'' The 1999 RHR's text of 
40 CFR 51.308(f), which indicates that states must evaluate and 
reassess all elements required by 40 CFR 51.308(d), requires states to 
evaluate and reassess the URP in the second and subsequent 
implementation periods. We explained in the proposal that 40 CFR 
51.308(d) is not perfectly clear as to whether the URP line for the 
second or later implementation periods must always start in the 
baseline period of 2000-2004, or whether the state must (or may) 
recalculate the starting point of the URP line based on data from the 
most recent 5-year period during each successive regional haze SIP 
revision.\97\ We also explained that although the regulations make 
clear that the endpoint of the URP line should be set based on 
attainment of the natural visibility condition for the 20 percent most 
impaired days in 2064, the 1999 RHR does not specify an exact date in 
2064 for this element.
---------------------------------------------------------------------------

    \97\ The preamble to the 1999 RHR provides an example explaining 
how a state would determine the 2028 point on the URP line. 64 FR at 
35746, n. 113. In this example, the URP line for the second 
implementation period starts at 2000-2004.
---------------------------------------------------------------------------

    To ensure consistent understanding of how the URP analysis must be 
done, the EPA proposed rule revisions in 40 CFR 51.308(f)(1)(i) and 
(vi) that would make it explicit that in every implementation period, 
the URP line for each Class I area is to be drawn starting on December 
31, 2004, at the value of the 2000-2004 baseline visibility conditions 
for the 20 percent most impaired days, and ending at the value of 
natural visibility conditions on December 31, 2064. Specifying that the 
5-year average baseline visibility conditions are associated with the 
date of December 31, 2004, and that natural visibility conditions are 
associated with the date of December 31, 2064, also clarifies that the 
period of time between the baseline period and natural visibility 
conditions, which is needed for determining the URP (deciviews/year) is 
60 years.
    Along with the clarification that the baseline period remains 2000-
2004 for subsequent implementation periods, the EPA also proposed 
clarifications in 40 CFR 51.308(f)(1)(i) regarding how states treat 
Class I areas without available monitoring data or Class I areas with 
incomplete monitoring data, as follows: If Class I areas do not have 
monitoring data for the baseline period, data from representative sites 
should be used; if baseline monitoring data are incomplete, states 
should use the 5 complete years closest to the baseline period. We 
proposed to add this provision to remove any uncertainty about how an 
issue of data incompleteness should be addressed in a SIP.
    Finally, we proposed language in 40 CFR 51.308(f)(3)(i) and an 
accompanying definition of ``end of the applicable implementation 
period'' in 40 CFR 51.301 to make clear that RPGs are to address the 
period extending to the end of the year of the due date of the next 
periodic comprehensive SIP revision.
2. Comments and Responses
    Some commenters were supportive of EPA's proposal to have the URP 
line start at 2000-2004 for every implementation period, although some 
asked for the option of recalculating the URP for the start of each 
implementation period based on how much further progress is needed to 
reach natural conditions given the progress already achieved. Other 
commenters did not agree with EPA's proposal and instead supported a 
revision to the regulations that would require states to reset the URP 
at current visibility conditions during each periodic review, provided 
those visibility conditions are better than during the baseline. Taking 
into account past improvements in visibility that were in excess of the 
URP in this way would result in a lower-lying URP line for successive 
planning periods. This could change the comparison of the RPG to the 
URP line, and trigger the

[[Page 3097]]

requirement of 40 CFR 51.308(f)(3)(ii) to show that there are no 
additional measures that would be reasonable to include in the long-
term strategy, when it would not be triggered if the start of the URP 
line had been kept at the 2000-2004 period.
    As explained in the 1999 RHR, the consideration of the improvement 
in visibility represented by the URP and the measures necessary to 
attain that level of improvement is an analytical requirement. In the 
1999 RHR, EPA adopted this required analysis in lieu of establishing 
presumptive reasonable progress targets, in part to provide equity 
between the goals set for the Class I areas in the more impaired 
eastern portion of the country as compared to the areas in the western 
portion. The URP analysis also helps to provide transparency to the 
overall regional haze SIP planning process, in part by requiring states 
to compare their RPGs to the rate of progress represented by the URP at 
each Class I areas. Neither of these goals would be served by allowing 
states to adopt differing approaches to the calculation of the URP.
    We have considered the comments suggesting that the URP be redrawn 
during each successive planning period. Although such an approach is 
apparently intended by commenters to maintain pressure on the states to 
adopt more comprehensive and effective reasonable progress strategies, 
it is not clear that this approach would in fact achieve that outcome 
because it may create disincentives for states to take aggressive 
action during the first few planning periods. This is because resetting 
the URP would make it more likely that a state that has taken early and 
aggressive action to improve visibility would become subject to the 
enhanced analytical requirement of 40 CFR 51.308(f)(3)(ii), thus 
generating a possible disincentive for continued progress.
    Because we have concluded that our proposed approach of starting 
the URP for every implementation period at 2000-2004 will result in the 
most equitable and transparent process and provide the strongest 
incentive for continued progress toward achieving natural visibility 
conditions, we are finalizing that approach with no changes to 40 CFR 
51.308(f)(1)(i) or (vi).
3. Final Rule
    The EPA is finalizing all of the previously described rule text 
without any changes from the proposal.
    The long-term strategy and the RPGs must provide for an improvement 
in visibility for the most impaired days and ensure no degradation for 
the clearest days.
1. Summary of Proposal
    Section 169A of the CAA requires a SIP to not only reduce existing 
visibility impairment but also to prevent future impairment. As part of 
meeting the goal of preventing future visibility impairment, 40 CFR 
51.308(d)(1) of the 1999 RHR requires a state to establish RPGs that 
ensure no degradation in visibility for the least impaired days over 
the period of the implementation plan. This text is ambiguous, however, 
as to whether ``the period of the implementation plan'' refers to the 
entire period since the baseline period of 2000-2004 or to the specific 
implementation period addressed by the periodic SIP revision. The 
proposal noted that a table in the preamble to the 1999 RHR summarizing 
certain requirements indicated that the 2000-2004 period would be used 
for ``tracking visibility improvement.'' \98\ To provide further 
clarity on this issue, we proposed new rule text in revised 40 CFR 
51.308(f)(3)(i) that would make clear that the requirement is for a 
state to establish an RPG for the 20 percent clearest days in each 
periodic review that ensures that there is no deterioration in 
visibility on the 20 percent clearest days as compared to the baseline 
period of 2000-2004. We note that while 40 CFR 308(d)(1) of the 1999 
RHR expresses the requirement of no degradation in visibility in terms 
of the RPG for the 20 percent clearest days, this requirement comes 
into play as a factor in what emission sources are subject to 
additional control measures in the long-term strategy, because this RPG 
is the projected result of implementing the long-term strategy. In 
other words, a state must adopt a long-term strategy that includes the 
necessary measures to ensure that the expected visibility on the 20 
percent clearest days at the end of the planning period, as represented 
by the RPG for these days, will not deteriorate as compared to the 
visibility condition for these days in 2000-2004.The rule text we 
proposed for 40 CFR 308(f)(3)(i) made this connection explicit by 
saying that the long-term strategy and the RPG must provide for no 
degradation.
---------------------------------------------------------------------------

    \98\ 64 FR 35730.
---------------------------------------------------------------------------

2. Comments and Responses
    The EPA received comments both in support of, and raising concerns 
with, the proposed changes. The commenters opposed to our proposal 
preferred that when a state documents that the RPG for the 20 percent 
clearest days (i.e., the projected visibility condition on the clearest 
days as of the end of the given implementation period) shows no 
degradation, the benchmark for that comparison should be the lowest 
measured impairment of either the baseline period or current conditions 
reported in any progress report or comprehensive periodic revision for 
the clearest days. The approach recommended by the commenter would mean 
that the benchmark for the no degradation comparison would ratchet down 
over time.
    One commenter pointed out that as proposed, 40 CFR 308(f)(3)(i) 
addressed not just the requirement for no degradation for the clearest 
days but also the requirement that there be an improvement for the most 
impaired days. This commenter noted that the relevant sentence of 40 
CFR 308(f)(3)(i) could be interpreted to mean that the baseline period 
of 2000-2004 is the benchmark for determining if the long-term strategy 
and RPG for the most impaired days provides for an improvement.\99\ The 
commenter said that the final rule should provide that the benchmark 
for the improvement requirement should be the lowest measured 
impairment of either the baseline period or current conditions reported 
in any progress report or comprehensive periodic revision for the most 
impaired days. The approach recommended by the commenter would mean 
that the benchmark for the improvement comparison would ratchet down 
over time.
---------------------------------------------------------------------------

    \99\ The relevant sentence in the rule reads, ``The long-term 
strategy and reasonable progress goals must provide for an 
improvement in visibility for the most impaired days and ensure no 
degradation in visibility for the clearest days since the baseline 
period.'' The concluding phrase ``since the baseline period'' can be 
taken to apply to only the clearest days, or to both the most 
impaired days and the clearest days.
---------------------------------------------------------------------------

    We are finalizing our proposal to clarify that the benchmark for 
the requirement for no degradation on the 20 percent clearest days is 
the 2000-2004 baseline visibility condition. Further, we are clarifying 
that the baseline visibility condition for the 20 percent most impaired 
days is also the benchmark for the requirement that the long-term 
strategy and RPGs provide for an improvement for the most impaired 
days. We are taking this approach in the final rule for several 
reasons.
    Visibility on the clearest days has been improving since the 2000-
2004 period in most Class I areas, generally tracking the improvements 
seen on the 20 percent haziest and 20 percent most

[[Page 3098]]

impaired days.\100\ We expect that it will continue to be the case that 
emission reduction measures that provide for reasonable progress on the 
20 percent most impaired days will also have benefits on the clearest 
days. Thus, we expect that there will be a continuing improvement on 
the clearest days regardless of the benchmark selected, even if the 
rule did not contain any requirement for no degradation on the clearest 
days. Even so, we believe that the no degradation requirement with the 
2000-2004 visibility condition as the benchmark is an appropriate 
backstop in the rule that will continue to require states to consider 
additional measures in the event that measures adopted to improve 
visibility on the most impaired days are insufficient to protect 
visibility on the clearest days.
---------------------------------------------------------------------------

    \100\ The RTC contains graphics illustrating these improvement 
trends. The only situations in which there has been degradation 
since 2000-2004 are at a few Class I areas in the Virgin Islands and 
Alaska where sea salt particles significantly contribute to light 
extinction on the clearest days and concentrations of such particles 
on those days have increased over this period.
---------------------------------------------------------------------------

    We are not adopting the approach of ratcheting down the benchmark 
for the no degradation requirement. If we were to do this, it might 
lead to unreasonable outcomes in some cases. Available air quality 
modeling approaches for forecasting visibility conditions are at 
present more uncertain when predicting low concentrations of 
visibility-impairing pollution than when predicting higher 
concentrations, making comparisons of two ``clean'' scenarios more 
uncertain. Such comparisons could become required for many areas and 
have critical implications for SIP approvals. Errors in such 
comparisons due to modeling system errors might lead to inappropriate 
SIP disapprovals if the benchmark for the no degradation requirement 
continually ratcheted down as progress is made. Another consideration 
is that even with a 5-year averaging approach, transient natural 
phenomena might cause a temporary improvement in visibility on the 
clearest days entirely unrelated to the content and implementation of 
states' long term strategies, which would permanently reduce the 
benchmark if the ratcheting approach were followed. It might then be 
very difficult or unreasonable for a state in subsequent periods to 
show no degradation relative to this lower benchmark given that on the 
clearest days influences from anthropogenic sources will be relatively 
small. Finally, we believe that consistency between the benchmark for 
the no degradation test and the starting point for the URP, across 
Class I areas in a given implementation period and across 
implementation periods, will aid public understanding and participation 
in SIP development. For these reasons, we are finalizing our proposal 
on this aspect of the RHR.
    In addition, we are finalizing wording in 40 CFR 308(f)(3)(i) that 
makes it clear that the baseline condition in 2000-2004 is also the 
benchmark for determining whether the long-term strategy and RPGs 
provide for an improvement in visibility for the most impaired days, 
but repeating the reference to this baseline so that it links 
unambiguously to that requirement as well as to the no degradation 
requirement. We recognize that since 2000-2004 there have been 
widespread improvements in visibility on the most impaired days and 
that this already accomplished improvement has created a ``cushion'' 
for a comparison to check that the RPG for the end of a future 
implementation period shows improvement. However, we disagree with the 
commenter's suggestion that the benchmark for the improvement 
requirement should ratchet down over time, for similar but not entirely 
identical reasons that we disagree regarding the no degradation 
requirement. The advantage of consistency to public understanding 
applies to the improvement requirement as well as to the no degradation 
requirement. While the problem of modeling uncertainty applies less to 
the most impaired days at this stage of the regional haze program, in 
later periods the most impaired days will be clearer than they are now 
and the difficulty of distinguishing differences may apply more 
strongly. Also, we are mindful of the potential for reducing incentives 
for states to take action during the first few planning periods. With 
the 2000-2004 period as the benchmark for the no degradation 
requirement, a state has an incentive to take early action to improve 
the clearest days because this will create a safety margin in case 
later developments outside the state's control cause an increase in 
impairment on these days. Ratcheting down the baseline for the no 
degradation requirement would remove this incentive for continued 
progress because it would never be possible for a state to create a 
safety margin.
    However, the use of the baseline period as the benchmark for the no 
degradation and improvement requirements does not mean that states are 
free to simply allow visibility levels to return to what they were in 
the baseline period, or to allow for degradation in visibility as 
compared to current conditions. If a state were to set an RPG that 
reflects a forecast of degradation during a particular period, the 
adequacy of the SIP would need to be carefully assessed. In this 
situation, additional measures may be necessary to ensure reasonable 
progress, depending on the underlying explanation for the forecasted 
degradation. It may be that a state would be able to show that any 
forecasted degradation is attributable to causes other than 
deficiencies in its long-term strategy, but such a demonstration would 
need to be carefully assessed. We note that for at least the next 
planning period or two, the requirement to consider the four statutory 
factors for a reasonably selected set of sources should result in the 
adoption of additional control measures that provide an improvement, 
especially for a state with sources that contribute to impairment at a 
Class I area with an RPG above the URP line.
3. Final Rule
    Upon careful consideration of public comments received on this 
issue, the EPA is finalizing the proposed rule with a clarifying edit 
to the proposed language to make it clear that the baseline visibility 
condition is also the benchmark for determining whether the long-term 
strategy and RPGs provide for an improvement in visibility on the most 
impaired days.
    The sentences of the final version of 40 CFR 51.308(f)(1)(i), 
regarding the calculation of the baseline visibility conditions, have 
been slightly reordered and reworded from the proposed version for 
clarity. In addition, the final sentence of this paragraph, regarding 
Class I areas that did not have IMPROVE monitoring stations installed 
in time to provide complete monitoring data for 2000-2004, has been re-
worded to clarify that ``closest'' means closest in time to 2000-2004 
and does not refer to another Class I area that is nearest in distance. 
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. Minor edits for 
clarity have also been included in the final versions of 40 CFR 
51.308(f)(1)(iii) and (iv).
    Analytical Obligation When the Reasonable Progress Goal for the 20 
Percent Most Impaired Days Is Not On or Below the URP Line.
1. Summary of Proposal
    The EPA proposed 40 CFR 51.308(f)(3)(ii) in order to clarify the

[[Page 3099]]

relationship between the RPG for the 20 percent most impaired days and 
the URP line. This relationship determines the content of the 
demonstration a state must submit to show that its long-term strategy 
provides for reasonable progress. This clarification was based upon the 
1999 RHR's text of 40 CFR 51.308(d)(1)(ii). That provision addresses 
required actions of a state containing a Class I area that has adopted 
an RPG for the area that provides for a slower rate of visibility 
improvement than that needed to attain natural conditions by 2064 
(i.e., an RPG for the 20 percent most impaired days that is above the 
URP line). The proposed text of 40 CFR 51.308(f)(3)(ii)(A) stated that 
if the RPG for a Class I area is above the URP line, the state 
containing the Class I area must demonstrate, based on the four 
reasonable progress factors, that there are no additional emission 
reduction measures for anthropogenic sources or groups of sources in 
the state that may be reasonably anticipated to contribute to 
visibility impairment that would be reasonable to include in the long-
term strategy, and that such a demonstration is required to be 
``robust.'' Specifically, this demonstration must include documentation 
of the criteria used to determine which sources or groups of sources 
were evaluated and of how the four factors were taken into 
consideration in selecting the measures for inclusion in its long-term 
strategy.
    In addition, in comparison with the 1999 RHR's 40 CFR 
51.308(d)(2)(iv) and 40 CFR 51.308(d)(3)(i) and (ii), the proposed 40 
CFR 51.308(f)(2)(iii) more clearly spelled out the respective 
consultation responsibilities of states containing Class I areas as 
well as states with sources that may reasonably be anticipated to cause 
or contribute to visibility impairment in those areas. To further 
clarify the obligations of what we are referring to as contributing 
states, we proposed 40 CFR 51.308(f)(3)(ii)(B) to specify that in a 
situation where the RPG for the most impaired days is set above the 
glidepath, a contributing state must make the same demonstration with 
respect to its own long-term strategy that is required of the state 
containing the Class I area, namely that there are no other measures 
needed to provide for reasonable progress. The intent of this proposal 
was to ensure that states perform rigorous analyses, and adopt measures 
necessary for reasonable progress, with respect to Class I areas that 
their sources contribute to, regardless of whether such areas are 
located within their borders. This proposed change clarifies that the 
RPG for the most impaired days in the SIP of the state containing the 
Class I area does not ``set the bar'' for the contributing state's 
long-term strategy.
2. Comments and Responses
    The EPA received comments both in support of, and opposed to, the 
proposed changes. Comments opposing these provisions stated that this 
additional requirement goes beyond the CAA's requirement to consider 
the four statutory factors. The EPA disagrees with this assertion. 
Congress declared a national goal of preventing any future and 
remedying any existing visibility impairment in Class I areas resulting 
from manmade air pollution and delegated to EPA the authority to 
promulgate regulations assuring reasonable progress toward meeting that 
goal. CAA section 169A(a)(1), (a)(4). The analytical obligations 
contained in 40 CFR 51.308(f)(3)(ii) are a mechanism to ensure that 
states are, in fact, making reasonable progress by requiring states in 
certain circumstances to demonstrate the reasonableness of their four-
factor analyses. In addition, some commenters suggested that the term 
``robust demonstration'' is overly vague and expressed concern that, 
essentially, the EPA could take advantage of this vagueness in order to 
form its own criteria for disapproval of a SIP. Most commenters did not 
supply any specific suggestions, simply stating either that the term 
should be clarified or that this provision should not be finalized, 
although one commenter suggested states be allowed to refer to 
information already submitted or contained in an applicable docket for 
purposes of such a demonstration. We disagree that the requirement of a 
``robust demonstration'' is vague. The provision requires the 
demonstration to be based on the analysis in 40 CFR 51.308(f)(2)(i), 
and further clarifies that the demonstration must document the criteria 
used to determine which sources or groups of sources were evaluated and 
how the four reasonable progress factors were considered. The purpose 
of this demonstration is to show that a state conducted its analysis in 
a reasonable manner and that there are no additional measures that 
would be reasonable to implement in a particular planning period. A 
state may refer to its own experience, past EPA actions, the preamble 
to this rule as proposed and this final rule preamble, and existing 
guidance documents for direction on what constitutes a reasoned 
determination. Additionally, the EPA recently issued a draft guidance 
document that addresses, among other things, the reasonable progress 
analysis, which we expect to finalize in the near future. This guidance 
can provide further direction regarding the types of information and 
analyses a state may provide in its demonstration under 40 CFR 
51.308(f)(3)(ii). The EPA is therefore finalizing this provision as 
proposed. In addition, one commenter stated that the ``robust 
demonstration'' language of the proposed 40 CFR 51.308(f)(3)(ii)(A) was 
missing from the proposed 40 CFR 51.308(f)(3)(ii)(B). The EPA agrees 
the necessary text was missing from proposal, as states with Class I 
areas should be subject to the same type of demonstration as those 
contributing states without Class I areas. Therefore, the final rule 
includes in the requirements for a contributing state in 40 CFR 
51.308(f)(3)(ii)(B) the same requirement for a robust demonstration 
that appeared only in 40 CFR 51.308(f)(3)(ii)(A) at proposal.
    Some commenters stated a desire for corresponding rule text dealing 
with situations where RPGs are equal to (``on'') or better than 
(``below'') the URP or glidepath. Several commenters stated that the 
URP or glidepath should be a ``safe harbor,'' opining that states 
should be permitted to analyze whether projected visibility conditions 
for the end of the implementation period will be on or below the 
glidepath based on on-the-books or on-the-way control measures, and 
that in such cases a four-factor analysis should not be required. Other 
commenters suggested a somewhat narrower entrance to a ``safe harbor,'' 
by suggesting that if current visibility conditions are already below 
the end-of-planning-period point on the URP line, a four-factor 
analysis should not be required. We do not agree with either of these 
recommendations. The CAA requires that each SIP revision contain long-
term strategies for making reasonable progress, and that in determining 
reasonable progress states must consider the four statutory 
factors.\101\ Treating the URP as a safe harbor would be inconsistent 
with the statutory requirement that states assess the potential to make 
further reasonable progress towards natural visibility goal in every 
implementation period. Even if a state is currently on or below the 
URP, there may be sources contributing to visibility impairment for 
which it would be reasonable to apply additional control measures in 
light of the four factors. Although it may conversely be the case that 
no such sources or control measures exist in a particular state with 
respect to a particular Class I area and implementation period, this 
should be determined based on a four-factor

[[Page 3100]]

analysis for a reasonable set of in-state sources that are contributing 
the most to the visibility impairment that is still occurring at the 
Class I area.\102\ It would bypass the four statutory factors and 
undermine the fundamental structure and purpose of the reasonable 
progress analysis to treat the URP as a safe harbor, or as a rigid 
requirement.
---------------------------------------------------------------------------

    \101\ CAA section 169A(b)(2)(B), (g)(1).
    \102\ The point that having a RPG that is on or below the URP 
line is not a safe harbor has been articulated in past actions such 
as the disapproval of the reasonable progress element of Arkansas' 
SIP (see fn 32). Our approval of the reasonable progress element of 
South Dakota's SIP is an example in which we approved the state's 
RPGs even though the RPG for the most impaired days for two Class I 
areas were above the respective URP lines, based on the state having 
adequately considered the four statutory factors for important 
contributing sources. 76 FR 76646 (December 8, 2011) (proposed 
action) and 77 FR 24845 (April 26, 2012) (final action).
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3. Final Rule

    The EPA is finalizing all of the previously described rule text 
without any changes from the proposal, with the exception of including 
in 40 CFR 51.308(f)(3)(ii)(B) the same requirement for a robust 
demonstration that appeared only in 40 CFR 51.308(f)(3)(ii)(A) at 
proposal.
    Emission inventories.
1. Summary of Proposal
    The EPA proposed language in 40 CFR 51.308(f)(2)(iv) regarding the 
``baseline emissions inventory'' to be used by a state in developing 
the technical basis for the state's long-term strategy. This was done 
in order to reconcile this section with changes that have occurred to 
40 CFR part 51, subpart A, Air Emissions Reporting Requirements, since 
the RHR was originally promulgated in 1999. The proposed changes were 
also intended to provide flexibility in the base inventory year the 
state chooses to use, as the EPA has always intended if there is good 
reason to use another inventory year.
2. Comments and Responses
    Commenters were split on whether to support the flexibility 
afforded by the proposed rule text for selecting a year other than the 
most recent NEI year as the year of the inventory to be used as the 
basis for developing the long-term strategy. Some commenters supported 
the proposal, while others preferred that EPA require or definitively 
endorse that the 2011 NEI can be used as the base year for modeling for 
the next periodic comprehensive SIP revisions. The latter view 
generally resulted from concerns that while additional NEI versions, 
such as the 2014 and 2017 NEI versions, should be available by the time 
periodic comprehensive SIP revisions are due in 2021, there would not 
be adequate time after release of these inventories to complete all the 
modeling and analysis work required.
    Consideration of these comments uncovered significant ambiguity in 
the text of 40 CFR 51.308(d)(3)(iii) of the 1999 RHR and ambiguity in 
the proposed new 40 CFR 51.308(f)(2)(iv) that would reflect 40 CFR 
51.308(d)(3)(iii). Specifically, the term ``the baseline inventory on 
which [the state's] strategies are based'' in the 1999 RHR can be taken 
to refer to the inventory that is used to assess the contribution that 
sources make to visibility impairment (and the visibility benefits of 
additional control measures, when such benefits are considered) for 
individual sources or groups of sources. That information is critical 
to the development of the long-term strategy and, in that sense, is the 
information on which a state's strategies are to be based. However, we 
believe that some commenters have taken the term to refer to the 
inventory that is used as the expected starting point for the 
photochemical modeling that they (and we) expect will be used to 
project the RPG that quantifies the projected effect of all the 
measures in the long-term strategy and other influences on visibility 
at the end of the implementation period. The two bodies of information 
are not necessarily the same, and they do not necessarily even need to 
be for the same year in order to develop a SIP that provides for 
reasonable progress. In fact, the modeled RPGs that are eventually 
included in a SIP revision do not directly affect the development of 
the long-term strategy, but rather they reflect that strategy. We are 
revising the proposed regulatory text to make this clear. The final 
regulations use the ``emissions information on which the State's 
strategies are based'' to refer to the inventory that is used to assess 
the contribution that sources make to visibility impairment and not to 
the base year inventory used to model the RPGs.
    The requirement in the final version of 40 CFR 51.308(f)(2)(iv) is 
that the emissions information on which the state is relying to 
determine the emission reduction measures that are necessary to make 
reasonable progress must include, but need not be limited to, 
information on emissions in a year at least as recent as the most 
recent year for which the State has submitted emission inventory 
information to the Administrator under the Air Emissions Reporting 
Requirements. To allow time for this information to be used in SIP 
development, the rule provides for a 12-month ``grace period'' such 
that a submission to the NEI in the period 12 months prior to the due 
date of the SIP does not trigger this requirement. We agree with the 
comments to the effect that there is no reason why a state should not 
make at least some information for the year of its most recent 
submission to the NEI part of the basis for its determination of the 
emission reduction measures that are necessary to make reasonable 
progress. The state is not required to use the same information as was 
submitted to the NEI, and it should not if it has developed or received 
better information for that year since its NEI submission. A state may 
also consider information for a more recent year if it is available and 
is of sufficient quality. Therefore, we do not believe it is necessary 
or appropriate for the RHR to provide for an exception to the 
requirement as it is stated in this section of the rule text and 
interpreted here. A state that plans to use information other than what 
is in the most recent NEI version released by the EPA to develop its 
long-term strategy should consult with its EPA regional office to 
obtain the EPA's preliminary perspective on whether there is a 
reasonable basis for its planned approach. This should also be a topic 
of the ongoing consultation with affected FLMs.
    The final version of 40 CFR 51.308(f)(2)(iv) does not address the 
question of the year to be used as the base year for emissions modeling 
of the RPGs. The EPA generally recommends that this be the year of the 
most recent NEI version that has been developed and validated enough to 
be appropriate for air quality modeling to support policy development. 
The final rule provides the EPA flexibility to approve a SIP based on 
another year if there are good reasons. States that believe that 
another year is more suitable should consult with the EPA Regional 
office about their reasons.
3. Final Rule
    For the reasons described previously, and also here, the final 
language for 40 CFR 51.308(f)(2)(iv) differs somewhat from the wording 
we proposed with respect to the terminology used to refer to emissions 
inventories. The final version of this subsection of the rule refers to 
the ``emissions information on which the state's strategies are 
based,'' rather than to a ``baseline'' emissions inventory. The final 
version also does not include a provision for EPA approval for 
selecting a year other than the year of the most recent submission 
under the Air Emissions Reporting Requirements as the year of the

[[Page 3101]]

inventory to be used as the basis for developing the long-term 
strategy. However, the final rule provides a 12-month grace period for 
the use of the year of the most recent submission under the Air 
Emissions Reporting Requirements. The rule does not address the 
selection of a year as the base year for emissions modeling of the RPGs 
for the end of the implementation period.
    EPA action on RPGs.
1. Summary of Proposal
    The proposed language of 40 CFR 51.308(f)(3)(iv) was intended to 
make clear that in approving a state's RPGs, the EPA will consider the 
controls and technical demonstration provided by a contributing state 
with respect to its long-term strategy, in addition to those developed 
by the state containing the Class I area with respect to its long-term 
strategy. This clarification was proposed in light of the 1999 RHR's 40 
CFR 51.308(d)(1)(iii), which only explicitly mentions the demonstration 
provided by the state containing the Class I area.
2. Comments and Responses
    No comments were received that specifically addressed this proposed 
rule text.
3. Final Rule
    The EPA is finalizing this rule text as proposed.
    Progress report elements of periodic comprehensive SIP revisions.
1. Summary of Proposal
    The proposed language in 40 CFR 51.308(f)(5) complemented proposed 
changes regarding progress reports and the proposal to eliminate 
separate progress reports being due simultaneously with periodic 
comprehensive SIP revisions by requiring periodic comprehensive SIP 
revisions to include certain information that would have been addressed 
in the progress reports. While the proposed language would expand the 
scope of periodic comprehensive SIP revisions, the same information 
would still be covered and states would no longer need to prepare and 
submit two separate documents (potentially containing overlapping 
content) at the same time.
2. Comments and Responses
    Few comments were received that specifically addressed this 
proposed rule text. Those that did address these provisions supported 
the proposed changes, with one comment additionally suggesting use of 
the terminology ``the most recent progress report'' instead of ``the 
past progress report,'' which EPA is incorporating into the final text 
(this is discussed later). In addition, one commenter noted that states 
should also be required to address the requirements of proposed 40 CFR 
51.308(g)(8) in periodic comprehensive SIP revisions. Proposed 40 CFR 
51.308(g)(6), renumbered in the final rule as 40 CFR 51.308(g)(8), 
requires progress reports to include a summary of the most recent 
assessment of smoke management programs operating within the state if 
such assessments are an element of the program. (As background, this is 
not a requirement of the 1999 RHR for either progress reports or 
periodic SIP revisions.) We agree that the provisions of 40 CFR 
51.308(f)(5) do not contain a requirement similar to the requirement in 
proposed 40 CFR 51.308(g)(6) or final 40 CFR 51.308(g)(8). However, for 
any state where smoke from prescribed fires is a significant 
contributor to visibility impairment, the analysis that it will perform 
under 40 CFR 51.308(f)(3)(iv)(D) as finalized (the requirement for a 
state to consider basic smoke management practices and smoke management 
programs) will serve the same purpose as would requiring periodic SIP 
revisions to summarize the conclusions of the most recent assessment of 
an existing smoke management program.
3. Final Rule
    The EPA is finalizing this rule text as proposed with only minor 
wording changes for clarity including a small change in wording in 
response to a public comment indicating confusion with the terminology 
``past progress report.'' The EPA agrees that this should instead refer 
to the ``most recent progress report'' and is finalizing revised text 
accordingly.

E. Changes to Definitions and Terminology Related to How Days Are 
Selected for Tracking Progress

1. Summary of Proposal
    The 1999 RHR's 40 CFR 51.308(d) required states to determine the 
visibility conditions (in deciviews) for the average of the 20 percent 
least impaired and 20 percent most impaired visibility days over a 
specified time period at each of their Class I areas. As discussed in 
detail in the preamble of the proposed rule, the definition of 
visibility impairment included in 40 CFR 51.301 of the 1999 RHR 
suggests that only visibility impacts from anthropogenic sources should 
be included when considering the degree of visibility impairment. 
However, the approach followed for the first implementation period 
involved selecting the least and most impaired days as the monitored 
days with the lowest and highest actual deciview levels regardless of 
the source of the particulate matter causing the visibility impairment. 
While the EPA approved SIPs using this approach for the first 
implementation period, experience now indicates that for the most 
impaired days an approach focusing on anthropogenic impairment is more 
appropriate because it will more effectively track whether states are 
making progress in controlling anthropogenic sources. Our proposed 
approach is also more consistent with the definition of visibility 
impairment in 40 CFR 51.301. Because the 1999 RHR rule text already 
refers to the 20 percent most impaired days, we did not propose to 
change that wording. In the preamble to the proposal, we made clear 
that going forward, we would interpret ``most impaired days'' to mean 
those with the greatest anthropogenic visibility impairment, as opposed 
to the 20 percent haziest days. We did not propose to change the 
approach of using the 20 percent of days with the best visibility to 
represent good visibility conditions for RPG and tracking purposes, but 
we did propose a rule text change to refer to them as the 20 percent 
clearest days rather than the 20 percent least impaired days.
    The proposal included changes to a number of the definitions in 40 
CFR 51.301 as well as added definitions for some previously undefined 
terms, including clearest days, the deciview index, natural visibility 
conditions and visibility.
    The EPA solicited comment on requiring all states to use the new 
meaning of ``most impaired days'' as referring to the days with the 
most anthropogenic impairment, as well as on a second proposed 
approach. In the second proposed rule alternative, states would be 
allowed to choose between selecting the 20 percent of days with the 
highest overall haze (i.e., the approach used in the first 
implementation period) and selecting the 20 percent of days with the 
most impairment from anthropogenic sources (the proposed new meaning). 
The EPA also solicited comment on any additional approaches.
2. Comments and Responses
    We received some comments favoring the first proposed rule 
alternative that expressed support for a single, consistent approach to 
selecting the 20 percent most impaired days for all states. However, 
the majority of comments from states favored the second proposed rule 
alternative due to

[[Page 3102]]

the flexibility it offered. Some comments on the second proposed rule 
alternative expressed concerns about, and requested guidance for, 
consultation between states in situations where two states use 
different approaches. Some comments favoring the second proposed rule 
alternative said that they anticipated that using the 20 percent most 
anthropogenically impaired days would mean an additional workload that 
would consume state resources during the planning process, and cited 
this as the reason they did not support the first proposed rule 
alternative. One commenter suggested that the final rule could allow 
states submitting their SIPs for the second implementation period by 
the 1999 RHR's deadline of July 31, 2018, to choose between using the 
20 percent most anthropogenically impaired days or the 20 percent 
haziest days, with states submitting later required to use the latter 
approach.
    After considering these comments and other considerations as 
described here, we are finalizing the first proposed alternative for 
the final rule (i.e., that ``most impaired days'' means those with the 
most anthropogenic impairment). The EPA often provides states 
flexibility when it may help achieve the objectives of SIP development 
and does not negatively implicate a program's objectives. In this 
particular situation, however, the flexibility of the second proposed 
rule approach would not significantly assist in developing efficient 
and effective SIPs and would likely result in confusion among 
stakeholders. For example, if two states with Class I areas in close 
proximity choose different approaches to the selection of days, the 
public might misunderstand how past and projected progress in improving 
visibility compares between the two areas. Also, allowing the state 
with a Class I area to unilaterally choose the selection approach for 
that area would raise the prospect that a contributing state might 
disagree with that choice, because the choice could make a difference 
in whether both states are subject to the enhanced analysis requirement 
of 40 CFR 51.308(f)(3)(ii), therefore complicating consultation among 
states. It would be possible for a state to choose a given approach 
simply because it would result in the best comparison of RPGs to the 
glidepath or URP for the implementation period being addressed by a SIP 
revision, and a state could conceivably switch back and forth between 
the two approaches from one period to another to get the best 
comparison for each period, causing additional confusion. In addition, 
we believe the approach of using anthropogenic impairment to select the 
20 percent worst days is more consistent with the intent of the 
original RHR, namely to reduce the aggregate effect that anthropogenic 
sources have on the visual experience of visitors to Class I areas.
    The EPA disagrees that concerns regarding additional workload and 
lack of resources preclude adopting the first proposed alternative. The 
EPA and IMPROVE program will work together to provide datasets that 
identify the most anthropogenically impaired days in each year of 
IMPROVE data and that contain the statistical summaries of these days 
need as part of a SIP revision or progress report. These datasets will 
be based on a specific method the EPA intends to recommend in a future 
guidance document. We expect that these datasets will avoid any 
increase in the workload and resources required of states relative to 
continued use of the haziest days. We will also work with any state or 
states interested in a different specific method for identifying the 
most impaired days than the one we will recommend, to avoid an increase 
in workload that would interfere with other aspects of SIP development.
    The final rule revisions requiring states to use the 20 percent of 
days with the greatest anthropogenic impairment do not have any direct 
implications for how states develop their long-term strategies. While 
these revisions may affect whether a state has to demonstrate that 
there are no additional measures that would be reasonable to include in 
the long-term strategy under the requirement of 40 CFR 
51.308(f)(3)(ii), these revisions do not prescribe how a state may make 
this demonstration. Thus, we believe that this requirement will not 
impair states' flexibility to appropriately analyze and address the 
sources of visibility impairment at Class I areas in and near their 
states.
    We are not making any changes in response to the comment suggesting 
that the final rule provide flexibility in the approach to the 
selection of the worst days only for areas that submit their SIP 
revisions by July 31, 2018. It is our understanding that only some 
eastern states may be submitting SIP revisions this early and that the 
states involved have not been experiencing erratic impacts from 
wildfires and dust storms. Therefore, we do not believe the special 
flexibility the commenter suggests is needed. As mentioned, any state 
may choose to include in its SIP a second summary of visibility data 
using the 20 percent haziest days approach, for public information 
purposes.
    Regarding the proposed changes to definitions, commenters 
recommended adding language to the definitions of most impaired days, 
regional haze, and visibility impairment to further clarify that these 
terms refer to impairment due to anthropogenic sources. The EPA agrees 
that some of the suggestions provided by commenters further clarify 
that visibility impairment is due to anthropogenic sources and does not 
include emissions from natural sources. Therefore, in response to these 
comments, we have finalized additional changes to the definitions of 
most impaired days, regional haze, and visibility impairment to also 
include the concept that impairment is anthropogenic.
    We also received comments on the proposed change to the definition 
of natural conditions and the proposed definition of natural visibility 
conditions. The commenters asked the EPA to further revise these 
definitions to reflect the reality that natural conditions have changed 
over time and will continue to change in the future; to make clear the 
timeframe of natural visibility conditions we intend to be captured by 
the definition; that natural visibility conditions may reflect poor 
visibility conditions; and to more explicitly include the factors 
contributing to natural visibility conditions (e.g., fire and dust 
events, volcanic activity, etc.). As a result of these comments, we are 
finalizing additional changes to these two definitions and adding 
definitions for two additional terms used in the rule. We are also 
providing further explanation of the role of natural visibility 
conditions in the SIP development process as follows.
    The EPA is finalizing the definition of natural conditions to 
include a list of example phenomena considered to be a part of natural 
conditions. The list provided is not intended to be exhaustive, but 
provides examples of some of the types of natural impacts that may 
affect Class I areas. We are also finalizing the definition of natural 
conditions to reflect the EPA's understanding that natural conditions 
not only will vary with time, but that they also may have long-term 
trends due to changes in the Earth's climate system. We have also 
clarified in this definition that natural phenomena both near to and 
far from a Class I area may impact visibility in the Class I area.
    To reduce confusion between the natural visibility that would exist 
on a single day and the average of a set of natural visibility values 
for a set of days, we are finalizing separate definitions of natural 
visibility and natural visibility

[[Page 3103]]

condition. Natural visibility will refer to visibility on a single day. 
The natural visibility definition includes language that recognizes 
natural visibility does vary daily and may contain long-term trends. 
Natural visibility condition will refer to the average of a set of 
values on an indicated set of days.
    In practice, the natural visibility condition for the 20 percent 
most impaired days is used by a state when developing the most 
appropriate 2064 endpoint for the URP line. Then the RPG for the 20 
percent most impaired days is to be compared with the point on the URP 
line corresponding to the end date of the implementation period, which 
will in effect be adjusted by a portion of the adjustment made to the 
2064 endpoint. The EPA invited comment on draft guidance \103\ to the 
states on how to determine the value of the 2064 natural visibility 
condition for the 20 percent most impaired days for each Class I area 
for purposes of calculating the URP, and we intend to provide final 
guidance on this topic separately from this action on revisions to the 
RHR.
---------------------------------------------------------------------------

    \103\ Draft Guidance on Progress Tracking Metrics, Long-Term 
Strategies, Reasonable Progress Goals and Other Requirements for 
Regional Haze State Implementation Plans for the Second 
Implementation Period. 81 FR 44608 (July 8, 2016).
---------------------------------------------------------------------------

    The need for clarity about the distinction between visibility on 
one day and the average of the visibility values for a set of days also 
applies to baseline visibility conditions and to current visibility 
conditions. To achieve this clarity, the final rule text includes new 
definitions of the terms baseline visibility condition and current 
visibility condition. These definitions are consistent with the way 
these terms are used in 40 CFR 51.308, but having these explicit 
definitions will improve understanding by participants in the regional 
haze program.
3. Final Rule
    The EPA is finalizing the requirement that all states select the 20 
percent most impaired days, i.e., the days with the most impairment 
from anthropogenic sources, as the ``worst'' days for purposes of 
calculating baseline visibility conditions, current visibility 
conditions, natural visibility conditions and the URP in SIPs and, as 
applicable, in progress reports. Under the final rule revisions, states 
retain the option to also present visibility data using the days with 
the highest overall deciview index values (i.e., the 20 percent haziest 
days), for public information purposes. Including this information in 
the SIP may help communicate to the public the magnitude of impacts 
from natural sources including wildland wildfires and dust storms. The 
RPGs and URP line that are calculated using anthropogenic impairment to 
select the most impaired days constitute the glidepath representing the 
state's determination of reasonable progress and, if appropriate, may 
trigger the requirement for a state to show that there are no 
additional emission reductions measures that would be reasonable to 
include in the long-term strategy (see Section IV.D of this document). 
Since the 20 percent most anthropogenically impaired days will, going 
forward, be used to estimate natural visibility conditions, current 
visibility conditions and the URP, they must also be used in setting 
RPGs and in progress reports. Conforming edits that were proposed to 
the provisions related to each of these calculations are likewise being 
finalized. As described at proposal, the revised approach will apply 
starting with the second and subsequent periodic comprehensive SIP 
revisions and will apply to progress reports starting with those 
submitted after the second SIP revision. EPA will continue to use the 
previous approach of considering the 20 percent haziest days with 
respect to SIP revisions submitted to satisfy the requirements of the 
first implementation period or initial progress reports.
    The EPA did not propose to require any particular method for 
determining the natural versus anthropogenic contributions to daily 
haze and thus the degree of visibility impairment for each monitored 
day. The EPA issued draft guidance \104\ describing a recommended 
approach along with a process for routinely providing relevant datasets 
for use by states when they develop their SIPs and progress reports. No 
particular method is being prescribed by the final rule nor will the 
final version of the guidance contain any binding requirements; states 
can therefore develop, justify and use another method of discerning 
natural and anthropogenic contributions to visibility impairment in 
their SIPs. The EPA intends to include more information on this subject 
in the final guidance.
---------------------------------------------------------------------------

    \104\ 81 FR 44608 (July 8, 2016).
---------------------------------------------------------------------------

    As described in the summary of comments on this topic, the EPA is 
finalizing the proposed changes to the definitions of clearest days, 
deciview, deciview index, least impaired days, and visibility along 
with additional changes we have determined are needed to further 
clarify the definitions of most impaired days, visibility impairment, 
regional haze, natural conditions, and natural visibility condition. 
The additional changes to these proposed definitions are intended to 
more clearly explain that impairment is from anthropogenic sources and 
that natural sources and their contributions to visibility vary over 
time. Additionally, the EPA is finalizing definitions for natural 
visibility, baseline visibility condition, and current visibility 
condition that we determined are needed to fully clarify the meanings 
of these terms.
    We are not finalizing the proposed change to the definition of a 
Federal Class I area that would have stated that non-mandatory Federal 
Class I areas are identified in 40 CFR part 52. There currently are no 
non-mandatory Federal Class I areas and the reference to 40 CFR part 52 
could have created confusion. The final definition of a mandatory Class 
I Federal area correctly indicates that the mandatory areas are 
identified in 40 CFR part 81 subpart D.

F. Impacts on Visibility From Anthropogenic Sources Outside the U.S.

1. Summary of Proposal
    In the proposal, the EPA acknowledged that emissions (natural and 
anthropogenic) from other countries and marine vessel activity in 
waters outside the U.S. may impact Class I areas, especially those 
areas near borders and coastlines. Prior to our proposal, several 
states with such Class I areas requested that they be allowed to adjust 
their URP line, visibility tracking metrics and RPGs to account for 
international anthropogenic impacts when preparing SIPs and progress 
reports.\105\ We therefore solicited comment on a proposed provision 
that would allow states with Class I areas significantly impacted by 
international anthropogenic emissions to adjust their URPs with 
approval from the Administrator.\106\ The proposed

[[Page 3104]]

adjustment would consist of adding to the value of the natural 
visibility condition for the 20 percent most impaired days in 2064 an 
estimate of the average impact from international anthropogenic sources 
on such days,\107\ for the sole purpose of calculating the URP.\108\ We 
also solicited comment on another possible approach to accounting for 
international anthropogenic impacts, in which the influence of 
emissions from anthropogenic sources outside the U.S. would be removed 
from estimates of 2000-2004 baseline visibility conditions, current 
visibility conditions and the RPG for the end of an implementation 
period.
---------------------------------------------------------------------------

    \105\ The impacts from natural sources located outside the U.S. 
can be large in certain Class I areas, but because the RHR treats 
impacts from all natural sources equally, those impacts are 
inherently properly included in the 2000-2004 baseline condition 
used as the starting point for the URP line and the natural 
visibility condition used as the 2064 endpoint of the URP line. 
Thus, the logical interest of these states was in a special 
adjustment for the impacts of anthropogenic sources outside the U.S. 
We note for clarity that under the final rule, prescribed fires 
outside of the U.S. are considered anthropogenic sources and thus 
the discussion in this section is relevant to such prescribed fires. 
Prescribed fires in wildland are also addressed in Section IV.G of 
this document.
    \106\ The 1999 RHR provided that if a state found that 
international emissions sources were affecting visibility conditions 
in a Class I area or interfering with plan implementation, that 
state could submit a technical demonstration in support of its 
finding. If EPA agreed with the finding, it would ``take appropriate 
action to address the international emissions through available 
mechanisms.'' 64 FR 35714, 35747 (July 1, 1999).
    \107\ The URP line is expressed in deciview units, so the value 
added to the natural visibility condition would also be in 
deciviews. However, that added deciview value would be based on the 
light extinction increments caused by the indicated sources.
    \108\ This proposed extra step in determining the URP was not 
intended to have the effect of defining international anthropogenic 
sources as natural, or to change any other aspect of SIP 
development.
---------------------------------------------------------------------------

    The proposal reflected the EPA's position that it may be 
appropriate to allow a state to adjust the RPG framework, including in 
its progress reports, to avoid any perception that a state should be 
aiming to compensate for impacts from international anthropogenic 
sources and to avoid requiring a state to undertake the additional 
analytical requirement under 40 CFR 51.308(f)(3)(ii) based solely on 
visibility impairment due to international anthropogenic sources. 
However, we proposed that an adjustment to compensate for such impacts 
would be available only when and if these impacts can be estimated with 
sufficient accuracy. In the proposal we stated that we do not expect 
that explicit consideration of impacts from anthropogenic sources 
outside the U.S. should or would actually affect the conclusions that 
states make about what emission controls for their own sources are 
necessary for reasonable progress. However, we explained that explicit 
quantification of international anthropogenic impacts, if accurate, 
could improve public understanding and effective participation in the 
development of regional haze SIPs. We also indicated that while we had 
not yet, at the time of the proposal, seen an approach that would allow 
states to adjust their visibility tracking metrics with sufficient 
accuracy, we expected that by the time some future periodic 
comprehensive SIP revisions are to be prepared, methods and data for 
estimating international anthropogenic impacts will be substantially 
more robust. Our proposal did not include any statement about whether 
EPA would provide estimates on international impacts or guidance on how 
states can estimate such impacts.
2. Comments and Responses
    Some commenters opposed allowing any adjustment to the URP, while 
others supported some sort of adjustment based on the impacts of 
international anthropogenic sources. Several commenters stated that the 
EPA or other federal entities should provide an approach to estimating 
international anthropogenic impacts, or actual estimates of such 
impacts, that are presumptively approvable, or that the EPA should give 
deference to any estimate a state develops. Some commenters inferred 
that the EPA's statements in the proposal regarding the current state 
of the art for estimating international anthropogenic impacts meant 
that no state would be able to obtain EPA approval for an adjustment in 
the SIP due in 2021. Several commenters objected to their understanding 
that the proposed rule would require a state to obtain EPA approval for 
a particular adjustment approach before including such an approach in 
its SIP submission. Finally, at least one commenter requested that EPA 
also provide rule language allowing for adjustment of the 20 percent 
clearest days framework to reflect the impacts of international 
anthropogenic sources.
    The EPA does not have a near-term plan to develop guidance on 
estimating international anthropogenic impacts or to provide such 
estimates specifically for the purpose of regional haze SIPs. However, 
the EPA is an active participant in research in this area and will 
continue to share its work with interested states and with others.\109\ 
To clarify, the statements in the preamble regarding the state of the 
art method refer to our assessment of the estimates and models for 
estimating international impacts available in the scientific literature 
at the time of this rulemaking. We did not intend to preclude or 
prejudge consideration of estimates that states may include in SIPs for 
the second implementation period or subsequent periods based on newer 
and more refined methodologies and/or information. Although we do not 
believe such estimates and models are currently able to adequately 
represent the impacts of international anthropogenic sources on 
visibility, we acknowledge that this is an area of active research and 
development that may lead to adequate estimates in time for the 
development of SIPs for the second implementation period. Additionally, 
the final rule text includes a small change to clarify that the 
Administrator's approval for an adjustment will be part of the 
Administrator's review of the full SIP submission for an implementation 
period, and not a separate action in advance of SIP submission. In this 
way, the Administrator's decision to approve or not approve the 
adjustment will be made in the context of the complete SIP submission, 
with public notice and an opportunity to comment. As with any SIP 
element, states are encouraged to consult with EPA Regional offices 
during the development of any proposed adjustment approach.
---------------------------------------------------------------------------

    \109\ For example, the EPA held a 2-day workshop in February 
2016 to advance the collective understanding of technical and policy 
issues associated with background ozone, which includes impacts from 
anthropogenic sources outside the U.S., as part of the agency's 
ongoing efforts to engage with states and stakeholders on 
implementation of the 2015 ozone NAAQS. While this workshop focused 
on ozone, the modeling issues and approaches for ozone are similar 
to those for visibility-impairing pollutants. More information on 
the EPA's activities and current understanding of this area can be 
found in the white paper available at https://www.epa.gov/ozone-pollution/background-ozone-workshop-and-information and other 
documents available in EPA number EPA-HQ-OAR-2016-0097 at https://www.regulations.gov.
---------------------------------------------------------------------------

    Because the EPA is not providing estimates of international 
anthropogenic impacts or guidance for calculating those impacts at this 
time, we are not specifying that any such estimates or methodologies 
are presumptively approvable. We further disagree with comments that 
states have inherent discretion to adjust their URP and RPG frameworks 
to account for impacts of international anthropogenic sources and that 
the EPA lacks the authority to review such adjustments. As explained in 
Section IV.B of this notice, the CAA mandates that the EPA promulgate 
regulations requiring that states' SIP submittals contain, among other 
things, ``measures as may be necessary to make reasonable progress 
toward meeting the national goal.'' \110\ Furthermore, the EPA is 
required to ensure that states' submittals meet the basic legal 
requirements and objectives of the CAA, including any regulations the 
agency promulgates for the purpose of ensuring that states make 
reasonable progress towards achieving natural visibility. A proposed 
adjustment to a state's RPG framework to address the impacts of 
international anthropogenic sources has the potential to affect that 
state's assessment of what constitutes reasonable progress. Thus, the 
EPA not only has the authority to review a state's

[[Page 3105]]

proposed adjustment, it has an obligation to do so.
---------------------------------------------------------------------------

    \110\ CAA section 169A(b)(2).
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    Finally, we disagree with the comment that we should provide rule 
language for states to adjust their frameworks for assessing visibility 
on the 20 percent clearest days to account for any impacts of 
international anthropogenic sources. First, particular days on which 
international anthropogenic sources have particularly strong impacts 
due to unusual source events or transport conditions are unlikely to be 
among the 20 percent clearest days in their respective years. The 
commenter presented no basis for anticipating that increasing impacts 
from anthropogenic sources on the clearest days might cause a state to 
be unable to satisfy the no degradation requirement without employing 
unreasonable measures for domestic sources. Second, our analysis 
indicates that such an adjustment would not have been necessary in the 
first implementation period, in that nearly all Class I areas in fact 
have had no degradation during this period so far, and the few that 
have experienced degradation have not done so because of impacts 
attributable to international anthropogenic sources. Improvements in 
visibility on the 20 percent clearest days have been significant enough 
so that we expect that states impacted by increased emissions from 
international anthropogenic sources in the second implementation period 
will still be able to comply with the requirement that visibility on 
those days show no degradation compared to 2000-2004 baseline 
conditions. The RTC contains more information on this improvement 
trend. The EPA will continue to assess this relationship throughout the 
second and subsequent implementation periods. Third, on clear days when 
there is relatively little visibility-impairing air pollution, it is 
difficult with our current tools to discern the portion of that air 
pollution originating from international anthropogenic sources, as 
opposed to domestic anthropogenic or natural sources and as compared to 
the assessment of the impact of international anthropogenic sources on 
the most impaired days. It would thus be unlikely that a state could 
estimate international anthropogenic impacts on the 20 percent clearest 
days with the requisite degree of accuracy at this time or when 
developing a SIP for the second implementation period.
3. Final Rule
    The EPA is finalizing the provision to allow an adjustment of the 
URP by adding an estimate for international anthropogenic impacts to 
2064 natural visibility conditions. We are not finalizing the 
alternative approach to accounting for international anthropogenic 
impacts that would have involved removing the influence of emissions 
from anthropogenic sources outside the U.S. when developing the 
estimates of 2000-2004 baseline visibility conditions, current 
visibility conditions and the RPGs. We are finalizing only one approach 
to provide consistency and transparency, as the alternative approach 
would have been more complicated and involved presenting numerous 
counterfactual values of visibility levels that could be mistaken as 
actual measured values.
    Because this adjustment is permitted only if the Administrator 
determines that a state has estimated the international impacts from 
anthropogenic sources outside the U.S. using scientifically valid data 
and methods, we are finalizing the rule text of 40 CFR 
51.308(f)(1)(vi)(B) as proposed, with a small change to clarify 
singular versus plural,\111\ as well as the aforementioned change to 
clarify that the Administrator's approval for an adjustment will be 
part of the Administrator's review of the full SIP submission for an 
implementation period, and not a separate action in advance of SIP 
submission.
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    \111\ Our proposed rule text used the phrase ``the State must 
add the estimated impacts [of international anthropogenic sources 
(or certain prescribed fires)] to natural visibility conditions and 
compare the resulting value to baseline visibility conditions.'' For 
consistency with our final definitions, this part of the final rule 
text instead refers to the natural visibility condition and the 
baseline visibility condition. The use of the plural form for 
``natural visibility conditions'' and ``baseline visibility 
conditions'' could give the impression that multiple values of 
impacts are to be added to multiple values of natural visibility 
conditions, when actually a single value reflecting impacts from 
international anthropogenic sources (or certain prescribed fires) is 
to be added to the single value of the ``natural visibility 
condition'' for the 20 percent most impaired days. The final rule 
text does not specify that the average of estimates of daily 
international impacts be used in this addition step, so that states 
can propose and the Administrator can approve another statistic to 
represent the distribution of daily values, for example the median 
value, if more appropriate.
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    In addition, we are finalizing the proposed rule text changes in 40 
CFR 51.308(f)(1)(i) and 40 CFR 51.308(f)(1)(vi) to remove ``needed to 
attain natural visibility conditions'' from the reference to ``uniform 
rate of progress,'' because when adjusted to reflect international 
impacts the ``uniform rate of progress'' would not be the rate of 
progress that would reach true natural visibility conditions.
    Because the manner in which a state with a Class I area calculates 
the URP may affect other states with sources that contribute to 
visibility impairment at the Class I area,\112\ we recommend that a 
state seeking approval for such an adjustment first consult with 
contributing states. Such an adjustment should also be a topic for the 
required consultation with the FLM for the Class I area at issue.
---------------------------------------------------------------------------

    \112\ Contributing states may be affected because under the 
final version of 40 CFR 51.308(f)(3)(iv)(B), a contributing state 
will have an additional analytical requirement if the RPG does not 
provide for the URP at an affected Class I area in another state.
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G. Impacts on Visibility From Wildland Fires

1. Summary of Proposal
    Fires on wildlands within and outside the U.S. can significantly 
impact visibility in some Class I areas on some days but have little to 
no impact in other Class I areas. And even in those Class I areas 
significantly impacted by fires on wildlands on some days, there are a 
greater number of days where fires do not have such impacts. The EPA 
presented an extensive discussion of wildland fire concepts, including 
actions that the manager of a prescribed fire can take to reduce the 
amount of smoke generated by a prescribed fire and/or to reduce public 
exposure to the smoke that is generated (i.e., basic smoke management 
practices), in the proposed and recently finalized revisions to the 
Exceptional Events Rule.\113\ That discussion is not repeated here.
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    \113\ 80 FR 72840 (November 20, 2015); 81 FR 68216 (October 3, 
2016). Both the preamble and final rule of the Exceptional Events 
Rule listed six basic smoke management practices with an important 
footnote which recognizes that those listed are not intended to be 
all-inclusive for the purpose of the Exceptional Events Rule. 
Section IV.G.2 of this document discusses the term ``basic smoke 
management practices'' in the context of the Regional Haze Rule.
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    The preamble for our proposed action discussed at length how the 
RHR relates to the management of wildland wildfires and wildland 
prescribed fires. The information presented there is applicable to 
states as guidance under these final RHR revisions, except as revised 
or supplemented as follows. There were many public comments on the 
subject of wildland fires, some of which are addressed in this section. 
We address the remaining comments in the RTC document for this action.
    We proposed new definitions for wildland, wildfire and prescribed 
fire. These proposed definitions were consistent with the definitions 
we had recently proposed be added to the Exceptional Events Rule. We 
said in the proposal for the Exceptional Events Rule that wildland can 
include

[[Page 3106]]

forestland, shrubland, grassland and wetlands, and that the proposed 
definition of wildland includes lands that are predominantly wildland, 
such as land in the wildland-urban interface. The proposed definition 
for wildfire included a provision that a wildfire that occurs 
predominantly on wildland is a natural event.
    We also proposed language for new 40 CFR 51.308(f)(2)(vi)(E) based 
on the provisions of the 1999 RHR's 40 CFR 51.308(d)(3)(v)(E), with 
updates to reflect terminology used within the air quality and land 
management communities. Specifically, we proposed to use the term 
``basic smoke management practices'' to better align with current usage 
of ``smoke management practices'' in the fire management community to 
refer to steps that a burn manager can take to reduce emissions during 
a prescribed fire. We also proposed to use the term ``wildland 
vegetation management purposes'' in lieu of ``forestry management 
purposes.'' This latter change was proposed in recognition of the fact 
that not all wildland for which fire and smoke are issues is forested. 
We also proposed to replace the phrase ``including plans as currently 
exist within the State for these purposes'' with ``and smoke management 
programs for prescribed fire as currently exist within the State.'' The 
term ``smoke management program'' is used within the fire management 
community to refer to a multi-participant program that seeks to 
influence or regulate both whether and when prescribed fires are 
conducted and, typically, the smoke management practices employed 
during a prescribed fire. We stated in the preamble of the proposal 
that this required consideration of smoke management programs only 
applies if the existing smoke management program has six key features: 
(i) Authorization to burn, (ii) minimizing air pollutant emissions, 
(iii) smoke management components of burn plans, (iv) public education 
and awareness, (v) surveillance and enforcement and (vi) program 
evaluation.
    We proposed that for a state with a long-term strategy that 
includes a smoke management program for prescribed fires on wildland, 
each required progress report must include a summary of the most recent 
periodic assessment of the smoke management program including 
conclusions the managers of the smoke management program or other 
reviewing body reached in the assessment as to whether the program is 
meeting its goals regarding improving ecosystem health and reducing the 
damaging effects of catastrophic wildfires. (Comments on this proposal 
are summarized in Section IV.H of this document.)
    We proposed that the Administrator may approve a state's proposal 
to adjust the URP to avoid subjecting a state to the additional 
analytical requirement of 40 CFR 51.308(f)(3)(ii) due to the impacts of 
wildland fire conducted with the objective to establish, restore and/or 
maintain sustainable and resilient wildland ecosystems, to reduce the 
risk of catastrophic wildfires, and/or to preserve endangered or 
threatened species for purposes of ecosystem health (objectives that we 
refer to here as ``wildland ecosystem health'') and public safety 
during which appropriate basic smoke management practices were applied. 
This aspect of the proposal did not address and did not apply to fires 
of any type on lands other than wildland or to burning on wildland that 
is for purposes of commercial logging slash disposal rather than 
wildland ecosystem health and public safety. This aspect of the 
proposal was not restricted to prescribed fires within the U.S.
    We proposed to revise the definition of ``fire'' to remove the 
phrase ``prescribed natural fire.'' However, we stated that the 
definition of ``fire'' that would be revised appears in 40 CFR 51.301, 
when it actually appears in 40 CFR 51.309(b)(4) and applies only to 40 
CFR 51.309. We inadvertently did not make any change to 40 CFR 
51.309(b)(4) in our proposed rule text. We proposed this revision to 
remove ``prescribed natural fire'' from the ``fire'' definition because 
the concept of a ``prescribed natural fire'' is inconsistent with our 
proposal that all prescribed fires be considered anthropogenic sources. 
We recognize that some prescribed fires are intended to emulate and/or 
mitigate natural wildfires that would otherwise occur at some point in 
time. We also recognize that some wildfires are appropriately allowed 
to proceed for some time over an area without suppression in order to 
help achieve land management objectives. However, to use the term 
``natural'' and ``prescribed'' in one definition would cause confusion.
    While the direction of these proposals was towards providing states 
considerable flexibility regarding measures to limit emissions from 
wildland prescribed fire after having given reasonable consideration to 
their options, it was not and is not our intention to in any way 
discourage federal, state, local or tribal agencies or private land 
owners from taking situation-appropriate steps to minimize emissions 
from prescribed fires on wildland or prescribed fires on other types of 
land.
2. Comments and Responses
    With regard to the definitions of prescribed fire and wildfire and 
the related question of whether each type of wildland fire should be 
considered as an anthropogenic versus non-anthropogenic event or 
source, some commenters said that all wildland prescribed fires, or at 
least all prescribed fires conducted under a smoke management program, 
should be treated as non-anthropogenic. Other commenters said that all 
or some wildfires should be treated as anthropogenic, noting that the 
occurrence of wildfires is not purely natural in that past human 
actions have affected fire risks and that current actions by humans 
initiate some wildfires. We disagree with these and similar comments. 
We recognize that prescribed fires in many cases are conducted because 
natural wildfires have been previously suppressed, or as a substitute 
for waiting for a wildfire to take place because conditions are such 
that a wildfire would pose high risks. We also recognize that human 
actions, in particular the suppression of wildfires in the past, have 
affected the propensity of some wildlands to experience wildfires from 
natural ignition sources such as lightning and that human actions such 
as arson or careless smoking, fireworks, target practice or backyard 
burning are the sources of the ignition of many wildland wildfires. 
Thus, there is some basis for the perspective that prescribed fires 
merit being treated somewhat like natural sources, as well as for the 
opposite view that wildfires merit being treated somewhat as 
anthropogenic sources. However, by declaring in section 169A(a) of the 
CAA a national goal of remedying visibility impairment in Class I areas 
``which impairment results from man-made air pollution,'' Congress 
established a bifurcation between anthropogenic and non-anthropogenic 
sources of air pollution. Given that prescribed fires involve conscious 
planning by humans, it would be unreasonable for the rule to 
categorically consider them to be natural events and natural sources of 
air pollution.\114\ We consider wildfires

[[Page 3107]]

having natural causes of ignition to be natural sources of air 
pollution. The provision that a wildfire that occurs predominantly on 
wildland is a natural event also encompasses wildfires initiated by 
human action because it is not always possible to determine the cause 
of ignition for some wildfires, and because once ignited the progress 
of these wildfires is largely determined by factors beyond human 
control at the time. Therefore, it is appropriate to treat both 
wildland wildfires with natural sources of ignition and the other types 
of wildfires encompassed by the definition in 40 CFR 51.301 as natural 
events and natural sources of air pollution.
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    \114\ As explained in footnote 95, the rationale for allowing an 
adjustment of the URP framework to address the impacts of wildland 
prescribed fires does not stem from the fact that we are treating 
these fires as natural sources of air pollution, as this is not the 
case. Rather, we are providing for an adjustment because we 
acknowledge that anthropogenic prescribed fire conducted for 
purposes of ecosystem health and public safety during which 
appropriate basic smoke management practices have been applied can 
be consistent with the goal of making reasonable progress towards 
natural visibility.
---------------------------------------------------------------------------

    These categorizations do not mean that prescribed fires necessarily 
should or can be regulated in a manner similar to sources that are more 
purely anthropogenic, such as industrial sources, or that no 
consideration should be given to how human actions affect wildfire 
occurrence. For the regional haze program, an implication of these 
categorizations is that states are not required to consider additional 
measures to reduce visibility impacts from wildfires when they develop 
their regional haze SIP submissions. However, we believe that it is in 
the public interest for states, and all managers of wildland, to 
consider such measures to limit wildfire impacts on visibility on an 
ongoing basis. We encourage them to do so, to help improve visitor 
experiences in Class I areas, to protect public safety and health and 
to protect ecosystems from the impacts of catastrophic wildfires. We 
also believe that it is in the public interest for states, and all land 
managers using prescribed fire, to consider measures that can reduce 
the impact of prescribed fires on visibility in Class I areas and other 
air quality objectives. As they consider measures to reduce the impacts 
of prescribed fires on visibility, states may consider the benefits of 
wildland prescribed fire use (including benefits to ecosystem health 
and reduction in the risk of catastrophic wildfires) and the 
opportunity provided by the final rule for a state to make an 
adjustment to the URP to account for the impact of certain prescribed 
fires.
    Regarding the proposal that would allow the Administrator to 
approve an adjustment to the URP for impacts from at least some 
wildland prescribed fires, some comments were in favor of this 
provision while others suggested minor changes to the proposed 
approach. Many comments did not support all the specifics of our 
proposal for adjustment of the URP. Many commenters also said that the 
EPA or the FLMs should provide guidance on how to estimate prescribed 
fire impacts for the purposes of this adjustment and/or provide the 
adjustment values themselves.
    Of those commenters who did not support all the specifics of our 
proposal, one commenter said that states should be required to apply 
the four statutory factors to prescribed fire in order to be eligible 
to make any adjustment to the URP for prescribed fire impacts. Other 
commenters said that adjustment should be allowed only for prescribed 
fires conducted in accordance with any applicable smoke management 
program. However, other commenters said that an adjustment should be 
allowed to reflect the impacts of all types of prescribed fire and not 
merely those that met the conditions proposed by the EPA based on 
ecosystem or public health protection and use of basic smoke management 
practices.
    We disagree with commenters that the adjustment of the URP should 
be based on the impact of all prescribed fires, or all wildland 
prescribed fires, rather than only wildland prescribed fire conducted 
for purposes of ecosystem health and public safety during which 
appropriate basic smoke management practices have been applied. The 
fires that meet these conditions are fires conducted for purposes and 
in accordance with practices that are consistent with the goal of 
making reasonable progress towards natural visibility. We note, 
however, that the availability of an adjustment to the URP for the 
impacts of these particular prescribed fires does not in any way 
restrict a state from considering additional measures or management 
programs to address their impacts on visibility. We recommend that as a 
state considers such measures, it should consult with managers of 
federal, state and private lands that would be subject to such 
measures; this may include federal agencies in addition to the federal 
land manager of the Class I areas affected by sources in the state, 
with whom consultation on the development of the SIP is a requirement 
of the final rule. Furthermore, it is appropriate that for prescribed 
fires conducted on lands other than wildlands, wildland fires conducted 
for other purposes and wildland fires conducted without application of 
basic smoke management practices, the URP should assume their impacts 
will diminish to zero by 2064, just as the URP effectively assumes with 
respect to other types of anthropogenic sources within the U.S.\115\ 
This will focus public and state attention on whether there are any 
reasonable measures for reducing impacts from these other types of 
prescribed fires. We also disagree with other commenters who 
recommended that the adjustment be more restrictive and apply only to 
prescribed fires conducted in compliance with a smoke management 
program, because this would make the adjustment unavailable to some 
states where it would be consistent with the goal of making reasonable 
progress and where an adjustment would be an appropriate efficiency and 
public communication approach.
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    \115\ If there is no adjustment of the 2064 endpoint of the URP 
line for impacts from international anthropogenic sources, the URP 
effectively assumes that emissions from these sources will be zero 
in 2064. If there is an adjustment, the URP effectively assumes that 
these sources continue to have emissions in 2064.
---------------------------------------------------------------------------

    We also disagree with commenters that states should be required to 
conduct a four-factor analysis for prescribed fire before being 
eligible to adjust their URPs for the impacts of such fires. As we 
explained earlier, we are limiting the availability of an adjustment to 
only those wildland prescribed fires conducted for the purposes of 
ecosystem health and public safety and in accordance with basic smoke 
management practices. These particular types of fires are generally 
consistent with the goal of making reasonable progress because they are 
most often conducted to improve ecosystem health and to reduce the risk 
of catastrophic wildfires, both of which can result in net beneficial 
impacts on visibility.\116\ Therefore, as

[[Page 3108]]

long as these fires are conducted in accordance with basic smoke 
management practices, an additional four-factor analysis in this 
specific case might serve no purpose. States may consider additional 
measures to address the impacts of these and other types of prescribed 
fires, on the basis of a formal four-factor analysis if they choose or 
after another form of consideration.\117\
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    \116\ There is similarity and a difference in the rationales for 
an adjustment of the URP related to impacts from anthropogenic 
sources outside the U.S. and an adjustment related to impacts from 
wildland prescribed fire conducted for reasons of ecosystem health 
and public safety with appropriate basic smoke management practices 
applied. Because states cannot control and should not be expected to 
compensate for impacts from international anthropogenic sources, 
such international impacts should not be the sole reason that the 
RPG is above the URP line. In contrast, states generally have 
authority to regulate wildland prescribed fires within their 
borders. However, because it is generally reasonable for wildland 
prescribed fires of the type described to be conducted as determined 
to be needed through appropriate planning processes, with 
appropriate basic smoke management practices to reduce smoke impacts 
on the public, states should have the flexibility to determine that 
limiting the number of such wildland prescribed fires is not 
necessary for reasonable progress. SIP development can be more 
efficient and the public will better understand the progress being 
made to control other types of sources if the URP is adjusted to 
remove the influence of any projected increase in application of 
this type of wildland prescribed fire. Also, as with international 
anthropogenic impacts, this will avoid such fire impacts from being 
a critical factor in whether the RPG is above the URP line.
    \117\ Another way of considering whether measures in addition to 
BSMP are appropriate for prescribed fires conducted to improve 
ecosystem health and to reduce the risk of catastrophic wildfires, 
and/or considering what measures are appropriate for other types of 
prescribed fires, could be to assess and conclude that a particular 
subcategory of prescribed fires does not meaningfully impact 
visibility at any Class I area. Such a conclusion could support a 
decision not to require additional measures for that subcategory in 
the LTS even though a formal four-factor analysis has not been 
completed. A state might also include in its LTS measures aimed at 
reducing impacts from a subcategory of prescribed fire because those 
measures are already in effect in the state due to another CAA 
requirement or due to state-only considerations. If so, a new formal 
four-factor analysis of those measures would not be useful.
---------------------------------------------------------------------------

    One commenter suggested that an adjustment for the impacts of 
prescribed fires also be allowed as part of the demonstration that the 
long-term strategy and RPGs ensure no degradation on the clearest days. 
We disagree with this suggestion. First, the impacts from prescribed 
fires will necessarily be small on the clearest days. The commenter 
presented no basis for anticipating that increasing impacts from 
prescribed fire on the clearest days might cause a state to be unable 
to satisfy the no degradation requirement without employing 
unreasonable measures for other source types. Second, our analysis 
indicates that such an adjustment would not have been necessary in the 
first implementation period, in that nearly all Class I areas in fact 
have had no degradation during this period so far, and the few that 
have experienced degradation have not done so because of impacts 
attributable to prescribed fire. Improvements in visibility on the 20 
percent clearest days have been significant enough so that we expect 
that states impacted by increased emissions from prescribed fire in the 
second implementation period will still be able to comply with the 
requirement that visibility on those days show no degradation compared 
to 2000-2004 baseline conditions. The RTC contains more information on 
this improvement trend. The EPA will continue to assess this 
relationship throughout the second and subsequent implementation 
periods. Finally, on clear days when there is relatively little 
visibility-impairing air pollution, it is difficult with our current 
tools to discern the portion of that air pollution originating from 
prescribed fire, as opposed to the assessment of the impact of 
prescribed fire on the most impaired days. It would thus be unlikely 
that a state could estimate prescribed fire impacts on the 20 percent 
clearest days with the requisite degree of accuracy at this time or 
when developing a SIP for the second implementation period.
    Regarding our proposal to use updated terminology in proposed 40 
CFR 51.308(f)(2)(vi)(E), some commenters said that ``basic smoke 
management practices'' was not the appropriate update of the term 
``smoke management techniques'' because the latter term is not 
explicitly restricted to ``basic'' techniques. We disagree with the 
commenter that the phrase ``basic smoke management practices'' could be 
interpreted as requiring a state to consider a narrower set of 
practices than the phrase ``smoke management techniques.'' The EPA 
listed six basic smoke management practices in both the preamble and 
final rule of the Exceptional Events Rule with an important footnote 
which recognizes that those listed are not intended to be all-inclusive 
for the purposes of the Exceptional Events Rule. We similarly consider 
the term ``basic smoke management practices'' in the context of the 
Regional Haze Rule as allowing for additional basic smoke management 
practices to be developed to address Class 1 visibility impacts. In 
addition, this paragraph of the Regional Haze Rule specifies what a 
state at a minimum must consider, and a state may consider other 
measures as well. Accordingly, the final rule text in 308(f)(2)(iv)(D) 
contains the phrase ``basic smoke management practices.''
    No commenters opposed the use of ``and smoke management programs'' 
in proposed 40 CFR 51.308(f)(2)(vi)(E) in place of ``including plans'' 
in 40 CFR 51.308(d)(3)(v)(E). However, there were other comments on 
proposed 40 CFR 51.308(f)(2)(vi)(E) that concern the proposed retention 
and meaning of the phrase ``as currently exist within the State for 
these purposes.'' One commenter supported the concept that only states 
with existing smoke management programs should be subject to this 
specific requirement to consider smoke management programs. Another 
commenter said that even with this restricted applicability, the 
requirement to consider smoke management programs was too prescriptive 
and states should be allowed to apply the same consideration to 
prescribed fires as generally apply for all sources. One group of 
commenters opposed the restriction to only states with existing smoke 
management programs, and further suggested that listing only smoke 
management practices and smoke management programs was insufficient and 
that the rule should also require all states to consider other measures 
to mitigate the impact of fire.
    After consideration of these comments and a review of how the EPA 
and the states have applied 40 CFR 51.308(d)(3)(v)(E) during the first 
implementation period, we decided that finalization of the phase ``as 
currently exist with the State for these purposes'' cannot be said to 
clearly be only a preservation of the existing requirement of the 1999 
RHR, particularly when combined with the replacement of ``including 
plans'' with ``and smoke management programs.'' In the first 
implementation period the EPA never relied on a narrow interpretation 
of the applicability of this part of 40 CFR 51.308(d)(3)(v)(E) in 
reviewing a SIP. The final rule does not include the phrase ``as 
currently exist with the State for these purposes'' because we have 
decided that there is no rational basis for the restriction.\118\
---------------------------------------------------------------------------

    \118\ Given the removal of the phrase ``as currently exist 
within the state,'' the interpretation we articulated in the 
proposal that this phrase refers only to smoke management programs 
with the six listed features listed in the proposal is no longer 
relevant.
---------------------------------------------------------------------------

    The final version of 40 CFR 51.308(f)(2)(iv)(D) (renumbered) 
requires that states consider basic smoke management practices and 
smoke management programs when developing their long-term strategies. 
As discussed in the preamble to our proposed action,\119\ these 
requirements do not require a state to adopt basic smoke management 
practices or programs into its regional haze SIP.\120\ As states 
consider whether to adopt new measures that might affect the ability of 
land managers to use prescribed fire, they may newly consider both the 
effectiveness of their smoke management programs in protecting 
visibility and the benefits of wildland prescribed fire for ecosystem 
health and public safety. There are many ways that a state can give new 
consideration to such practices and programs. For example, a state can 
consider the need for including such measures in its SIP without 
shoehorning them into a formal four-factor analysis. A state can also 
consider them by determining based on analysis of IMPROVE data that 
fires in general, and thus prescribed fires in

[[Page 3109]]

particular, are not a significant contributor to reduced visibility at 
the Class I areas in the state (or impacted by the state). Therefore, 
this requirement of the final rule will not impose a difficult 
analytical burden on states or require them to adopt unreasonable 
measures. However, a state cannot unreasonably determine that a 
requirement for burn managers to use certain basic smoke management 
practices is not necessary to make reasonable progress. If a state 
determines that a requirement for burn managers to use certain smoke 
management practices is necessary to make reasonable progress, the 
long-term strategy must include such measure(s) in enforceable form. 
The same applies to consideration of a smoke management program. One 
possible outcome may be that a state reasonably does not make such a 
formal determination, but nevertheless decides to revise its current 
program regarding prescribed fires without incorporating the program 
(or the program enhancements) into the SIP. Such an action could 
indicate that the state has satisfied the requirement to consider basic 
smoke management practices and smoke management programs.
---------------------------------------------------------------------------

    \119\ See 81 FR 26958-59.
    \120\ Also, the EPA is not recommending that all states adopt 
any particular measures for wildland fire because situations vary 
too much from state to state and within states for any general 
recommendation to be appropriate.
---------------------------------------------------------------------------

    States also have the flexibility to allow reasonable use of 
prescribed fire. As previously noted, one approach to reducing the 
occurrence of wildland wildfires, and the risk of wildfires having 
catastrophic impacts, is appropriate use of prescribed fire. The EPA 
and the federal land management agencies will continue to work with the 
states as they consider how use of prescribed fire may reduce the 
frequency, geographic scale and intensity of natural wildfires, such 
that vistas in Class I areas will be clearer on more days of the year, 
to the enjoyment of visitors. States may also consider how the use of 
prescribed fire on wildland can benefit ecosystem health, protect 
public health from the air quality impacts of catastrophic wildfires 
and protect against other risks from catastrophic wildfires. These 
final rule revisions give states that have considered these factors, 
and other relevant factors, the flexibility to provide and plan for the 
use of prescribed fire, with basic smoke management practices applied, 
to an extent and in a manner that states and the EPA believe 
appropriate. The EPA is committed to working with states, tribes, 
federal land managers, other stakeholders and other federal agencies on 
matters concerning the use of prescribed fire, as appropriate, to 
reduce the impact of wildland fire emissions on visibility.
3. Final Rule
    We are finalizing the fire-related definitions as proposed, 
including the revision of the definition of ``fire'' in 40 CFR 
51.309(b)(4), with one change from proposal. We are finalizing a 
different definition of ``wildfire'' than we proposed. The final 
revised definition of a wildfire includes ``a prescribed fire that has 
developed into a wildfire'' instead of the proposed language ``a 
prescribed fire that has been declared to be a wildfire.'' Two comments 
in this rulemaking objected to or asked for clarification of the 
meaning of the ``declared to be a wildfire'' portion of the definition. 
The definition of wildfire being finalized for the RHR in this final 
action is the same definition as recently finalized for the revised 
Exceptional Events Rule, as commenters in both rulemakings raised 
similar concerns about the proposed definition. Consistent with the 
approach taken in the final revised Exceptional Events Rule, we 
concluded that whether a prescribed fire should be treated as a 
wildfire for regional haze program purposes depends on the facts of the 
situation. Specifically, the final definition includes the phrase ``a 
prescribed fire that has developed into a wildfire,'' which means a 
prescribed fire that has ``developed in an unplanned way such that its 
management challenges are essentially the same as if it had been 
initiated by an unplanned ignition.'' See 81 FR 68250. While we 
proposed, and are finalizing, a definition of ``wildfire'' that 
includes a statement that a wildfire that predominantly occurs on 
wildland is a natural event, we do not intend to restrict a wildfire on 
other types of land from also being treated as a natural event or 
source, based on specific facts about the wildfire.
    We are also finalizing 40 CFR 51.308(f)(3)(ii) as proposed to 
provide an adjustment to the URP framework for the 20 percent most 
impaired days due to the impacts of wildland fire conducted with the 
objective to establish, restore and/or maintain sustainable and 
resilient wildland ecosystems, to reduce the risk of catastrophic 
wildfires, and/or to preserve endangered or threatened species for 
purposes of ecosystem health and public safety during which appropriate 
basic smoke management practices were applied. Such an adjustment is 
not available for fires of any type on lands other than wildland or to 
burning on wildland that is for purposes of commercial logging slash 
disposal rather than wildland ecosystem health and public safety.
    We are also finalizing the term ``basic smoke management 
practices'' as an update of the term ``smoke management techniques'' in 
40 CFR 51.308(f)(2)(iv)(D) (renumbered). We are also finalizing the use 
of ``smoke management programs'' where the 1999 RHR used the term 
``plans.'' The final rule differs from the proposal in that it does not 
include the phrase ``as currently exist within the State for these 
purposes.''
    This action also deletes the obsolete and duplicative definition of 
``base year'' in 40 CFR 51.309(b)(8) and reserves that section number. 
The definition of ``base year'' in 40 CFR 51.309(b)(7) is the operative 
definition for this section of the RHR. The definition being deleted 
refers to 40 CFR 51.309(f) which is reserved in the current rule.

H. Clarification of and Changes to the Required Content of Progress 
Reports

1. Summary of Proposal
    The proposed rule detailed additional revisions to 40 CFR 51.308(g) 
in order to clarify the substance of the regional haze progress 
reports, given ambiguities in the 1999 RHR with respect to, among other 
things, the period to be used for calculating current visibility 
conditions, and whether forward-looking, quantitative modeling is 
required in the progress reports to assess whether RPGs will be met. 
These proposed revisions were numerous and often independent of one 
another, and are summarized briefly as follows.
    A proposed revision to the opening portion of 40 CFR 51.308(g) 
would have required that a state provide the public with a 60-day 
comment period on a draft progress report that is not a SIP revision, 
before submitting it to the EPA. The 1999 RHR did not explicitly say 
that a public comment period was required for progress reports, because 
other EPA rules require public notice for all SIP revisions and under 
the 1999 RHR progress reports have been SIP revisions.
    Proposed revisions to 40 CFR 51.308(g)(3)(ii) added a number of 
explanatory sentences to better indicate what ``current visibility 
conditions'' are and how to calculate them, given that it is not clear 
what ``current visibility conditions'' are in the 1999 RHR. 
Practicality requires that ``current conditions'' should mean 
``conditions for the most recent period of available data.'' \121\ The 
proposed text also made

[[Page 3110]]

clear that the period for calculating current visibility conditions is 
the most recent rolling 5-year period for which IMPROVE data are 
available as of a date 6 months preceding the required date of the 
progress report, given our belief that (since we also proposed that 
progress reports no longer be submitted as SIP revisions) this period 
would be sufficient for states to incorporate the most recent available 
data into their progress reports.\122\ We also invited comment on other 
specific appropriate timeframes, including 3 months, 9 months and 12 
months.
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    \121\ In our guidance on the preparation of progress reports, 
the EPA indicated that for ``current visibility conditions,'' the 
reports should include the 5-year average that includes the most 
recent quality assured public data available at the time the state 
submits its 5-year progress report for public review. See section 
II.C of General Principles for the 5-Year Regional Haze Progress 
Reports for the Initial Regional Haze State Implementation Plans, 
April 2013.
    \122\ Note that we are not proposing this specification of 6 
months for the progress report aspects of a periodic comprehensive 
SIP revision (see Section IV.E of this document), in light of the 
longer time needed for administrative steps between completion of 
technical work and submission to the EPA.
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    Proposed revisions to 40 CFR 51.308(g)(3)(iii) were designed to 
remedy a gap in the 1999 RHR, which failed to make clear what the 
``past 5 years'' are for assessing the change in visibility impairment. 
We proposed to delete the ``past 5 years'' text and replace it with 
text indicating the change in visibility impairment is to be assessed 
over the span of time since the period addressed in the most recent 
periodic comprehensive SIP revision. The EPA believed this would remedy 
the issue that, because of data reporting delays, the period covered by 
available monitoring data will not line up with the periods defined by 
the submission dates for progress reports, and would ensure that each 
year of visibility information is included either in a periodic 
comprehensive SIP revision or the progress report that follows it. We 
proposed to make the same change to the 1999 RHR's ``past 5 years'' 
text in the first sentence of 40 CFR 51.308(g)(4) for the purposes of 
reporting changes in emissions of pollutants contributing to visibility 
impairment, for similar reasons.
    We proposed several other revisions, particularly to 40 CFR 
51.308(g)(4), to revise and clarify the states' obligations regarding 
emissions inventories. One issue was that the 1999 RHR's text seemingly 
required a state to project emissions inventories to the end of the 
``applicable 5-year period'' whenever that endpoint is not the year of 
a triennial inventory (2011, 2014, etc.) required by 40 CFR part 51 
subpart A (Air Emissions Reporting Requirements). For a variety of 
reasons more fully explained in the preamble to our proposal, we 
proposed text changes that explain clearly that states must include in 
their progress reports the emissions, by sector, from all sources and 
activities up to the triennial year for which information has already 
been submitted to the NEI. With regard to emissions data for EGUs, 
states would need to include data up to the most recent year for which 
the EPA has provided a state-level summary of such EGU-reported data. 
Finally, the last sentence of the proposed text for 40 CFR 51.308(g)(4) 
made clear that if emission estimation methods have changed from one 
reporting year to the next, states need not backcast (i.e., use the 
newest methods to repeat the estimation of emissions in earlier years) 
in order to create a consistent trend line over the whole period, since 
although some states expressed concern that other parties may interpret 
the 1999 RHR as requiring it, the EPA has never expected states to 
backcast in this context.
    We also proposed changes to 40 CFR 51.308(g)(5), which requires 
assessments of any significant changes in anthropogenic emissions that 
have occurred, consistent with our proposed changes to other sections. 
Specifically, we proposed to delete the reference to the ``past 5 
years'' and instead direct states that the period to be assessed 
involves that since the last periodic comprehensive SIP revision. We 
also proposed text that would require states to report whether these 
changes were anticipated in the most recent SIP, given that this would 
assist the FLMs, the public and the EPA in understanding the 
significance of any change in emissions for the adequacy of the SIP to 
achieve established visibility improvement goals.
    The EPA further proposed to renumber the 40 CFR 51.308(g)(6) of the 
1999 RHR as 40 CFR 51.308(g)(7), and proposed to change that provision 
to clarify that the RPGs to be assessed are those established for the 
period covered by the most recent periodic comprehensive SIP revision. 
The proposed change did not alter the intended meaning of this section, 
and simply clarified that in a progress report, a state is not required 
to look forward to visibility conditions beyond the end of the current 
implementation period.
    The proposed, new 40 CFR 51.308(g)(6) included a provision 
requiring a state with a long-term strategy that includes a smoke 
management program for prescribed fires on wildland to include in each 
required progress report a summary of the most recent periodic 
assessment of the smoke management program, including conclusions that 
were reached in the assessment as to whether the program is meeting its 
goals regarding improving ecosystem health and reducing the damaging 
effects of catastrophic wildfires.
    A final proposed change to 40 CFR 51.308(g) removed the provisions 
of 40 CFR 51.308(g)(7) of the 1999 RHR entirely, relieving the state of 
the need to review its visibility monitoring strategy within the 
context of the progress report, a change that had been requested by 
many states during our pre-proposal consultations. Such a change was 
appropriate since all states currently rely on their participation in 
the IMPROVE monitoring program (and expect to continue to do so), so 
continuing the requirement for every state to submit a distinct 
monitoring strategy element in each progress report would consume state 
and EPA resources with little or no practical value for visibility 
protection.
    Finally, we proposed minor changes to 40 CFR 51.308(h) and 40 CFR 
51.308(i). Proposed changes to 40 CFR 51.308(h) regarding actions the 
state is required to take based on the progress report merely removed 
the implication that all progress reports are to be submitted at 5-year 
intervals, and aimed to improve public understanding of the declaration 
that a state must make when it determines that no SIP revisions are 
required. The proposed changes to 40 CFR 51.308(i) created a stand-
alone requirement that states must consult with FLMs regarding progress 
reports because the 1999 RHR only applies FLM consultation requirements 
to SIP revisions (and the proposal would remove the formal SIP revision 
requirement from progress reports).
2. Comments and Responses
    Several commenters pointed out that while there is no explicit 
provision in the 1999 RHR for the public to comment prior to the 
submission of progress reports for the first implementation period, 
which are required to be SIP revisions, other provisions in EPA rules 
require states to provide at least a 30-day notice to the public on any 
type of SIP revision, in contrast to the 60-day period we proposed to 
require for progress reports that are not SIP revisions. The commenters 
generally opposed the longer period and noted that it, in combination 
with the requirement to consult with FLMs well ahead of the start of 
public comment, would make it more difficult to meet the requirement 
that progress reports contain emissions and air quality

[[Page 3111]]

information no older than 6 months. We agree that retaining the current 
requirement for a 30-day public comment period is appropriate and are 
finalizing that period. States may provide a longer comment period, 
either initially or upon request, and we recommend that states do so 
when it would not prevent timely submission to the EPA.
    Some commenters opposed the proposed provision in 40 CFR 
51.308(g)(3)(ii) making clear that the period for calculating current 
visibility conditions is the most recent rolling 5-year period for 
which IMPROVE data are available as of a date 6 months preceding the 
required date of the progress report. As discussed previously, we also 
invited comment on other specific timeframes, and most of these 
commenters felt 12 months to be a more appropriate timeframe. However, 
in general these comments pointed specifically to the proposed 
provision requiring consultation with FLMs 60 to 120 days prior to a 
public hearing or other public comment opportunity on progress reports, 
and/or pointed to the proposed requirement for a 60-day public comment 
opportunity, as the reason for a 12-month period for IMPROVE data 
availability. However, as noted elsewhere in this document these two 
review/comment periods are not being finalized as proposed. In 
addition, the argument of several commenters that 6 months is an 
insufficient period to incorporate IMPROVE data even without the 
extended FLM consultation period was not well supported. Therefore, the 
EPA does not find these comments persuasive given the other content of 
the final rule.
    One commenter on the proposed 40 CFR 51.308(g)(3)(ii) noted that 
given the fact that progress reports for the first implementation 
period have often not been submitted on time, the EPA should adjust the 
language of the rule text such that the period for calculating current 
visibility conditions should be based on the later of the required date 
or submittal date of the progress report. The EPA disagrees with this 
assessment because this could create a situation requiring a state to 
re-analyze data (and substantially re-draft portions of a progress 
report) in situations where submittal of a progress report is delayed 
for valid or unforeseeable reasons. We note that there will be other 
avenues for the public and the EPA to obtain the most recent IMPROVE 
data if a late progress report does not have the most current 
information.
    Comments on the proposed revisions to 40 CFR 51.308(g)(4) regarding 
emissions tracking were numerous and varied, with many commenters 
expressing reservations about the proposed text. In general, these 
commenters asked that the EPA either not require states to use NEI data 
unless such data are available in final form a minimum of 12 months 
prior to the due date of the progress report, or that states should use 
the most recent final NEI data available at the time the progress 
report is prepared. In response, we want to reiterate that our proposal 
addressed only the requirement for the time period for the emissions 
information to be included in a progress report. We did not propose to 
require that the emissions data actually submitted to or contained in 
any version of the NEI be used in a progress report. Our intention is 
that a state have the flexibility to update and revise such data prior 
to presenting it in a progress report, but not the flexibility to limit 
its presentation to only emissions information for earlier years.\123\ 
Second, we acknowledge that, as proposed, this subsection could be 
interpreted to trigger a requirement to present emissions data for a 
certain year should data for that year be made available for the first 
time the day before the planned submission of a progress report. We are 
therefore finalizing additional text in 40 CFR 51.308(g)(4) (similar to 
text proposed and being finalized in 40 CFR 51.308(g)(3)) making clear 
that only NEI emissions data submitted by the state to the 
Administrator (or, in the case of data submitted directly by sources to 
a centralized emissions data system, made available in a state-level 
summary by the Administrator) at least 6 months prior to the due date 
for the progress report triggers the requirement that the progress 
report include emissions information for that year.
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    \123\ This point about updating and revising data for a 
particular year also applies to emissions information made available 
by the Administrator in a state-level summary. It is possible that a 
state may have more recent, more complete or more accurate data for 
its sources than the Administrator has been able to include in his 
or her state-level summary for a particular year.
---------------------------------------------------------------------------

    Proposed changes to 40 CFR 51.308(g)(5) involving assessments of 
any significant changes in anthropogenic emissions that have occurred 
since the period addressed in the last SIP revision were generally well 
received, however, one commenter asked that the EPA require additional 
specificity in this assessment. The EPA did not make any changes in 
response to this comment because the rule we are finalizing already 
includes the required information.
    Comments on the proposed, new 40 CFR 51.308(g)(6) regarding a 
progress report including a summary of the most recent periodic 
assessment of any existing smoke management program that is part of the 
long-term strategy were numerous, with some commenters generally 
favoring and all but one state opposing this additional rule provision. 
The comments in opposition to the new provision appear to interpret it 
as creating a requirement that states periodically assess their smoke 
management programs and whether these programs are meeting their goals. 
However, the proposed provision was not intended to create any such 
requirement. It merely intended that if there is a smoke management 
program in the long-term strategy that already has a periodic program 
assessment element, the findings and recommendation of the most recent 
assessment must be summarized in the regional haze progress report. We 
are finalizing small changes from the proposed provision to make this 
intention clear. We reiterate that we interpret this provision to only 
apply to smoke management programs that have been made part of the 
long-term strategy in the regional haze SIP, and only to programs that 
have a program evaluation element. A state that has such a smoke 
management program and has included its program in its regional haze 
SIP has acknowledged that management of smoke is a significant concern 
with respect to visibility. Providing the public with easy access to a 
summary of the most recent program assessment via the regional haze 
progress report will facilitate public participation in the state's 
development of its next SIP revision. The benefit of including a 
summary of the program assessment for a smoke management program that 
is not part of the SIP in the progress report, if there has been a 
program assessment, may be less, and we believe a state should have 
flexibility to include or not include such a summary in its progress 
report.
    Regarding the proposed 40 CFR 51.308(g)(7) (which as proposed was 
simply a modified version of the 1999 RHR's 40 CFR 51.308(g)(6) that 
clarified that a progress report's required assessment of whether a SIP 
is sufficient to meet established RPGs should address the RPGs defined 
for the end of the particular implementation period), the few comments 
received from states indicated a general opposition to the requirement 
to evaluate SIP adequacy to meet RPGs. The EPA did not propose to 
remove this function of the progress reports, so comments in favor of 
removing it are outside the scope of this rulemaking.

[[Page 3112]]

    The proposed removal of the provisions of the 1999 RHR's 40 CFR 
51.308(g)(7), designed to relieve the state of the need to review its 
visibility monitoring strategy within the context of the progress 
report, received few comments, but was generally opposed by 
conservation organization commenters and favored by state commenters. 
With respect to the progress reports that will be due in the second and 
subsequent implementation period, the reasoning for eliminating these 
provisions as explained in the proposal remains valid even in light of 
the comments received. However, upon further consideration it is 
appropriate to leave in place the requirement for a monitoring strategy 
element for the remaining progress reports due in the first 
implementation period, as many progress reports have already been 
submitted and many others are well under development. Being consistent 
with respect to this requirement for all progress reports during the 
first implementation period will not be a significant burden on the 
states. We have not disapproved the monitoring strategy element of any 
progress report to date.
    The RTC responds to these comments in more detail.
    Public comments on 40 CFR 51.308(i) regarding the requirement for 
consultation with FLMs on progress reports are discussed elsewhere in 
this document.
3. Final Rule
    The EPA is finalizing all of the rule text detailed in the 
preceding discussion as proposed with changes. Instead of removing the 
1999 RHR's 40 CFR 51.308(g)(7) regarding monitoring strategies 
entirely, we are retaining it but making it applicable only to progress 
reports for the first implementation period. With the retention of 40 
CFR 51.308(g)(7), the numbering of other sections in the final rule is 
different than proposed and is consistent with the numbering in the 
1999 RHR. We are revising the opening text of 40 CFR 51.308(g) to make 
the required public comment period be 30 days rather than 60 days. We 
are revising 40 CFR 51.308(g)(4) to provide a 6-month grace period for 
the trigger of the requirement to include emissions information for a 
recent year. The final version of new 40 CFR 51.308(g)(8) (numbered as 
(g)(6) in the proposal) has been revised from the proposal to clarify 
its applicability.
    We are finalizing rule text in 40 CFR 51.308(g)(7) that makes it 
clear that all remaining progress reports for the first implementation 
period submitted after these rule revisions are finalized must address 
the monitoring strategy, as has been the requirement of the 1999 RHR 
for progress reports already submitted. A progress report for the 
second or a subsequent implementation period will not have to address 
the monitoring strategy.

I. Changes to Reasonably Attributable Visibility Impairment Provisions

1. Summary of Proposal
    The EPA proposed extensive changes to 40 CFR 51.300 through 51.308 
with regard to reasonably attributable visibility impairment. The 
motivation for these changes was discussed in detail in the proposal. 
In summary, in the time since the reasonably attributable visibility 
impairment provisions were originally promulgated in 1980, advances in 
ambient monitoring, emissions quantification, emission control 
technology and meteorological and air quality modeling have been built 
into the regional haze program, such that state compliance with the 
RHR's requirements will largely ensure that progress is made towards 
the goal of natural visibility conditions. Therefore, some aspects of 
the reasonably attributable visibility impairment provisions of the 
visibility regulations have less potential benefit than they did when 
they originally took effect. These provisions have received few 
revisions over the years resulting in a substantial amount of confusing 
and outdated language within the current visibility regulations 
including seemingly overlapping and redundant requirements. While there 
have historically been very few certifications of existing reasonably 
attributable visibility impairment by an FLM, in several situations a 
certification by an FLM has ultimately resulted in new controls or 
changes in source operation.
    The EPA therefore proposed to (1) eliminate recurring requirements 
on states that we believe have no significant benefit for visibility 
protection; (2) clarify and strengthen the 1999 RHR's provisions under 
which states must address reasonably attributable visibility impairment 
when an FLM certifies that such impairment is occurring in a particular 
Class I area due to a single source or a small number of sources; (3) 
remove FIP provisions that require the EPA to periodically assess 
whether reasonably attributable visibility impairment is occurring and 
to respond to FLM certifications; and (4) edit various portions of 40 
CFR 51.300 through 40 CFR 51.308 to make them clearer and more 
compatible with each other. The EPA solicited comment on each of the 
proposed changes as well as suggestions for alternative approaches.
    Specific proposed provisions included:
     Revisions to 40 CFR 51.300, Purpose and applicability, to 
expand the reasonably attributable visibility impairment requirements 
to all states in light of the evolved understanding that pollutants 
emitted from one or a small number of sources can affect Class I areas 
many miles away.
     Revisions to 40 CFR 51.301, Definitions, to change the 
definition of reasonably attributable in order to make clear that a 
state does not have complete discretion to determine what techniques 
are appropriate for attributing visibility impairment to specific 
sources.
     Deletion of the entire text of 40 CFR 51.302 and 
replacement with new language clearly describing a state's 
responsibilities upon receiving a FLM certification of reasonably 
attributable visibility impairment. The following aspects of the 
proposed 40 CFR 51.302 are of particular relevance in summarizing 
comments and explaining our final action.
    [cir] The proposed 40 CFR 51.302(b) described the required state 
action in response to any FLM certification of reasonably attributable 
visibility impairment, namely that a state shall revise its regional 
haze implementation plan to include a determination, based on the four 
reasonable progress factors set forth in 40 CFR 51.308(d)(1)(i)(A), of 
any controls necessary on the certified source(s) to make reasonable 
progress toward natural visibility conditions in the affected Class I 
area. This would preserve the existing state obligation, including the 
fact that a certification by an FLM would not create a definite state 
obligation to adopt a new control requirement, but rather only to 
submit a SIP revision that provides for any controls necessary for 
reasonable progress. It would be the EPA, not the certifying FLM, that 
would determine whether the responding SIP is adequate and the response 
reasonable.
    [cir] The proposed 40 CFR 51.302(c) addressed those situations 
where an FLM certifies as a reasonably attributable visibility 
impairment source a BART-eligible source where there is at that time no 
SIP or FIP in place setting BART emission limits for that source or 
addressing BART requirements via a better-than-BART alternative 
program.\124\ In such an instance, the

[[Page 3113]]

proposed rule would require the state to revise its regional haze SIP 
to meet the requirements of 40 CFR 51.308(e), BART requirements for 
regional haze visibility impairment, and notes that this requirement 
exists in addition to the requirements of 40 CFR 51.302(b) regarding 
imposition of controls for reasonable progress. The proposed version of 
40 CFR 51.302(c) also clarified two aspects of the 1999 RHR to match 
the EPA's past and current interpretations. First, while a 
certification of reasonably attributable visibility impairment for a 
BART-eligible source prior to the EPA's approval of a state's BART SIP 
for that source does not impose any substantive obligation on a state 
that is over and above the BART obligation imposed by 40 CFR 51.308, 
the state's response to the certification of reasonably attributable 
visibility impairment for a BART-eligible source must take into account 
current information. Second, a certification of reasonably attributable 
visibility impairment for a BART-eligible source after the state's BART 
SIP for that source has been approved by the EPA does not trigger a 
requirement for a new BART determination based on the five statutory 
factors for BART, but rather, the state's obligation with respect to 
that source is the same as for a non-BART eligible source.
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    \124\ Although most of the BART requirements have been addressed 
in most states, there remain a handful of states with BART 
obligations. In addition, there is litigation over the BART element 
in some approved SIPs and promulgated FIPs. We expect that this 
situation may exist in one or more states at some time after the 
effective date of the final rule.
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    [cir] Three alternatives were proposed for 40 CFR 51.302(d) 
regarding the time schedule for state response to an FLM certification 
of reasonably attributable visibility impairment.
     Revisions to 40 CFR 51.303, Exemptions from control, to 
correctly refer to the new 40 CFR 51.302(c) as well as to the BART 
provisions in 40 CFR 51.308(e). Note that these revisions were 
described in the preamble of the proposal, but were inadvertently not 
included in the proposed rule text.
     Revisions to 40 CFR 51.304, Identification of integral 
vistas, to remove antiquated language in light of the fact that FLMs 
were required to identify any such integral vistas on or before 
December 31, 1985, and to list those few integral vistas that were 
properly identified.
     Revisions to 40 CFR 51.305, Monitoring for reasonably 
attributable visibility impairment, to state that the requirement to 
include in a periodic comprehensive SIP revision a monitoring strategy 
specifically for reasonably attributable visibility impairment in Class 
I area(s) only applies in situations where the Administrator, Regional 
Administrator or FLM has advised the state of a need for it.
     Complete removal of 40 CFR 51.306.
     Revisions to 40 CFR 51.308 (in addition to those discussed 
elsewhere in this document and in the proposal) related to reasonably 
attributable visibility impairment.
     Revisions to 40 CFR 51.308(e), BART, relating to a state's 
option to enact an emissions trading program or other alternative 
measure in lieu of source-specific BART.
    Finally, consistent with our proposal to remove the requirement for 
states to periodically assess reasonably attributable visibility 
impairment, the EPA proposed to revise many sections of 40 CFR part 52 
to remove provisions that establish FIPs that require the EPA to 
periodically assess whether reasonably attributable visibility 
impairment exists at Class I areas in certain states and to address it 
if it does, and to respond to any certification of reasonably 
attributable visibility impairment that may be directed to a state that 
does not have an approved reasonably attributable visibility impairment 
SIP.
2. Comments and Responses
    Comments on the proposed revisions to 40 CFR 51.300 regarding the 
expansion of reasonably attributable visibility impairment to states 
that do not have Class I areas were mixed across stakeholder groups. 
While few commenters expressed disagreement with the EPA's statements 
surrounding the improved scientific understanding of long-range 
pollutant transport showing that reasonably attributable visibility 
impairment can be an interstate issue, commenters opposing the 
reasonably attributable visibility impairment expansion generally 
pointed to the alleged redundant nature of the reasonably attributable 
visibility impairment and regional haze requirements, as well as 
asserting that any and all FLM concerns can be raised during the SIP 
development process. Using similar arguments, a number of commenters 
urged the EPA to remove the reasonably attributable visibility 
impairment requirements entirely, although this was not an option 
outlined in the proposal.
    A number of comments on the proposed revisions to 40 CFR 51.301 
regarding definitions opined that changing the definition of 
``reasonably attributable'' (to remove implied state discretion in 
determining whether the technique used was appropriate) would 
significantly alter the federal-state relationship in the visibility 
program and give FLMs authority beyond that afforded in sections 169A 
and 169B of the CAA. In response, the EPA is clarifying that the text 
edit to remove the phrase ``the state deems'' from the definition of 
``reasonably attributable'' was not intended to give the FLMs sole 
power to determine what technique is appropriate for attributing 
visibility impairment to a source or small number of sources. If and 
when an FLM makes a certification, it can base the certification on a 
technique that it thinks appropriate. Whether that technique is 
appropriate is an issue that the affected state may opine on during the 
consultation opportunity the FLM is required to offer (details of this 
consultation opportunity are discussed later) and as part of its 
responsive SIP revision. If the state believes that the technique is 
not appropriate and that no appropriate technique would verify the 
attribution alleged by the FLM, the state may submit a narrative-only 
SIP revision that disagrees with the certification and explains the 
reason for the disagreement, and accordingly contains no additional 
measures for the identified source or sources. However, it will be the 
EPA that ultimately determines whether the technique was appropriate, 
when we approve or disapprove the responsive SIP revision after 
considering the information that supports the certification, the 
information in the SIP revision, and public comments. This change in 
the rule text does not alter the federal-state relationship, because 
even under the wording of the 1999 RHR, the EPA would review the 
reasonableness of a state's determination as to what technique is 
appropriate for attributing visibility impairment.
    Several of these comments also ask that, if the EPA finalizes this 
change in definition, that the scope of attribution techniques which 
would qualify as ``appropriate'' be better stated. On this point, the 
EPA does not believe imposing such limits on the scope of techniques 
that qualify as ``appropriate'' is justified, particularly given that 
continually improving scientific understanding of pollutant transport 
and the continually evolving scope of modeling will no doubt result in 
even better attribution techniques in the future.
    Other comments on 40 CFR 51.301 asked for a more descriptive and 
thorough definition of ``reasonably attributable visibility 
impairment'' and its related terms. Comments on 40 CFR 51.302 regarding 
FLM certification of reasonably attributable visibility impairment 
contained similar requests,

[[Page 3114]]

with most states and industry expressing concern that the proposed rule 
did not define sufficiently limiting principles for FLMs, failed to 
identify information about the scientific basis for any certification 
of reasonably attributable visibility impairment, and did not provide 
any basis by which a state or source could review or object to any 
certification of reasonably attributable visibility impairment before 
it triggered a mandatory obligation to respond. Several commenters 
asked for guidance or criteria in the final rule for the certification 
process and techniques for attribution, with some providing a suggested 
list of elements to include in a certification of reasonably 
attributable visibility impairment.
    The comments in favor of a more specific provision in the final 
rule for what type of source impact, assessed by what method, 
constitutes reasonable attributable visibility impairment did not offer 
any particular more specific definition of reasonably attributable 
visibility impairment, and we had not proposed any more specific 
definition. While the EPA acknowledges the comments, we do not think it 
is necessary to finalize a more specific definition in the rule text. 
The EPA agrees with the portion of one comment letter suggesting that a 
thorough certification of reasonably attributable visibility impairment 
should describe the location(s) within the Class I area where the 
impairment occurs, when (e.g., year-round or only during certain times 
of the year) the impairment occurs, what attribution methods were used 
to determine impairment (such as photographs or videos, monitoring, 
and/or modeling), a description of how the impairment adversely impacts 
visibility, an identification of the source or sources believed by the 
FLM to be causing the impairment and the methods used to make this 
determination. Past reasonably attributable visibility impairment 
certifications have generally included these elements or the certifying 
FLM otherwise shared such information with the state.
    Additional comments on 40 CFR 51.302 asked for some degree of state 
participation in certification development, such as a pre-certification 
consultation requirement whereby FLMs must consult with states (and 
possibly EPA) before certifying, as well as an option for the state to 
appeal a certification once received. In response to these comments, we 
are including a consultation obligation on the FLMs in the final rule 
text. We would like to reiterate the importance of state-FLM 
consultation for all aspects of the RHR, including reasonably 
attributable visibility impairment. While the final rule requires the 
FLM to offer a state an in-person consultation meeting at least 60 days 
prior to making a certification of reasonably attributable visibility 
impairment, we encourage FLMs and state to have conversations and 
exchange technical information even earlier. The FLMs have conveyed to 
the EPA their expectation that a reasonably attributable visibility 
impairment certification will be an unusual ``backstop'' for a 
situation that is not otherwise addressed under the regional haze 
program despite good communication between the FLM and the state. In 
addition, in each instance since the original regulations were 
promulgated since 1980, FLMs have consulted with states and EPA and 
only made the decision to certify reasonably attributable visibility 
impairment when these conversations did not lead to a resolution of the 
issue.
    One commenter said that there is no provision in the 1980 rule on 
reasonably attributable visibility impairment that allows an FLM to 
make a certification for a source that is not BART-eligible. This 
commenter objected to the explicit provisions in our proposed rule 
revisions that provide for such a certification. We disagree with the 
commenter's description of the 1980 rule. We recognize that the term 
``existing stationary facility'' was defined in the 1980 rule as 
including only BART-eligible sources, and that many of the provisions 
of the 1980 rule were specific to these sources. However, the 1980 
rule's definition of reasonably attributable visibility impairment 
refers to ``air pollutants from one, or a small number of sources,'' 
not more narrowly to ``existing stationary facilities.'' Also, 40 CFR 
51.302(c)(2)(i) as promulgated in 1980 says that a state plan to 
address reasonably attributable visibility impairment must include a 
strategy ``as may be necessary to make reasonable progress towards the 
national goal'' and 40 CFR 51.302(c)(2)(ii) requires an assessment of 
how each element of the plan relates to preventing visibility 
impairment. Neither of these sections is limited to only ``existing 
stationary facilities.'' In addition, 40 CFR 51.302(c)(3) as 
promulgated in 1980 required plans to require ``each source'' to 
maintain control equipment and to establish procedures to ensure the 
equipment is properly operated and maintained. While the remaining 
parts of 40 CFR 51.302(c) contain more specific requirements that apply 
when a certification of reasonably attributable visibility impairment 
has identified an ``existing stationary facility'', the existence of 
these requirements does not mean that an FLM may not make a 
certification for another type of source or that a state has no 
obligation to submit a SIP revision to respond to the certification. 
Furthermore, as explained in more detail in the RTC, we believe that 
the CAA provides broad enough authority for the EPA to promulgate the 
provisions in the final rule regarding the certification of reasonably 
attributable visibility impairment by sources that are not BART-
eligible, regardless of how these sources were addressed in the 1980 
rule. If a certification is made for a source (or a small number of 
sources) that is not BART-eligible (or for a BART-eligible source for 
which the EPA has already approved or promulgated a plan addressing the 
BART requirement), the responsive SIP revision must provide for 
whatever measures for that source are necessary to make reasonable 
progress considering the four statutory factors, unless the SIP 
revision establishes that there is no reasonably attributable 
visibility impairment due to the identified source.
    There were a number of comments on 40 CFR 51.302(d) regarding the 
proposed three options for a schedule for state response to a 
certification of reasonably attributable visibility impairment. Some 
commenters recommended the first proposed approach of keeping the 1999 
RHR's schedule under which a state response is due within 3 years of a 
certification of reasonably attributable visibility impairment. Most 
commenters found the third proposed approach to be unnecessarily 
complicated, while some objected to how much time could elapse between 
a certification and the state's responsive SIP revision; we are not 
finalizing the third approach and will not discuss it further. Some 
commenters favored a modified version of the second proposed option (in 
which the deadline would be the earlier of the due date for the next 
progress report or periodic comprehensive SIP revision, so long as that 
submission is due at least 2 years after the certification), but with 
more time to respond. These commenters generally stated that the 
minimum workable time was either 3 or 4 years. It is noteworthy, 
however, that other commenters opposed this second option, largely due 
to the fact that in some situations a state response would not be due 
for some time after an FLM certification (up to 7 years).
    We noted that if the second approach were finalized but with the 
minimum time to respond to a certification increased to 3 or 4 years 
(as recommended by some states),

[[Page 3115]]

responses to FLM certifications may not be due until 8 or 9 years after 
certification, which is an excessive amount of time. The EPA believes 
that retaining the fixed 3-year deadline of the existing rule is 
workable for all parties and is most appropriate and hence is 
finalizing the first option in this rulemaking, with an added provision 
that no response will be due before the July 31, 2021, due date of the 
next SIP revision.\125\ While not specifically proposed, this provision 
is being finalized in response to the general concern of some 
commenters with a state having to respond to a reasonably attributable 
visibility impairment certification before it has had an opportunity to 
systematically consider what additional emission reductions measures 
are necessary for reasonable progress for the second implementation 
period taking into account all the requirements of this final rule.
---------------------------------------------------------------------------

    \125\ The added provision that refers to July 31, 2021, will 
have the effect of providing additional time for the state's 
response only for a reasonably attributable visibility impairment 
certification made prior to July 31, 2018.
---------------------------------------------------------------------------

    While we did not publish specific proposed rule changes for 
removing all mention of integral vistas from the visibility protection 
rules, we invited comment on such a step. We did so because it appeared 
that if we finalized our other proposals, there would be no requirement 
in our rules that actually depends on whether an integral vista 
associated with a Class I area had been identified. Thus, removing 
mention of integral vistas would simplify the rule text without 
changing any party's obligations under our visibility protection rules. 
A number of commenters agreed with our assessment and supported the 
removal of all mention of integral vistas, and no commenter opposed 
this change. However, we now realize that because the definition in 40 
CFR 51.301 that ``visibility in any mandatory Class I Federal area 
includes any integral vista associated with that area'' and because 
there are several provisions that after our final action continue to 
use the term ``visibility in any mandatory Class I Federal area,'' 
there are some provisions where the existence of a single identified 
integral vista could conceivably make a difference to the obligation of 
some party or to an EPA action. For this reason, we are finalizing only 
what we proposed, which is removal of antiquated language in section 40 
CFR 51.304, but not removal of all references to integral vistas in 
subpart P.
    For a discussion of the comments on other areas proposed and being 
finalized related to reasonably attributable visibility impairment, 
please see the RTC document available in the docket for this 
rulemaking.
3. Final Rule
    We are finalizing the proposed revisions to the reasonably 
attributable visibility impairment and related provisions, with four 
changes.
    First, as mentioned in the Section IV.I.2 of this document, we are 
finalizing a modified version of one of the proposed alternatives 
regarding the deadline for state response to a certification of 
reasonably attributable visibility impairment certification, namely 
that the response would always be due within 3 years (as required by 
the existing rule). The final rule retains this option's 3-year, fixed 
deadline rather than one of the alternative schemes proposed that would 
have always aligned the deadline with the next SIP revision or progress 
report, but adds an additional one-time provision such that a state 
response to a certification of reasonably attributable visibility 
impairment will in no case be due earlier than July 31, 2021. The final 
rule retains the language indicating that the state is not required at 
the time of response to also revise its RPGs to reflect the additional 
emission reductions required from the source or sources.
    Second, we are adding to 40 CFR 51.308(e)(2)(v) and 40 CFR 
51.308(e)(4) references to the reasonably attributable visibility 
impairment provisions in 40 CFR 51.302(b) and 40 CFR 51.302(c). We 
proposed to add to each of these parts of the rule only a reference to 
40 CFR 51.302(b) but have realized that a reference in each to 40 CFR 
51.302(c) is also needed. With these revisions, it is clear that for a 
BART-eligible source participating in a trading program that has been 
determined to be better-than-BART, if an FLM certifies that there is 
reasonably attributable visibility impairment due to that source a 
state may include a geographic enhancement of the trading program to 
satisfy both the reasonable progress obligation under 40 CFR 51.302(b) 
and any outstanding BART obligation under 40 CFR 51.302(c). While most 
BART-eligible sources cannot become subject to 40 CFR 51.302(c) because 
an approved BART SIP (or a SIP under 40 CFR 51.309) or a FIP is in 
place as a result of planning efforts in the first implementation 
period, there are a small number of BART-eligible sources that might 
become subject to 40 CFR 51.302(c) and it is important to be clear that 
a geographic enhancement is an option for them, as it has been under 
the 1999 RHR.
    Third, also mentioned in the preceding section, we are finalizing a 
requirement in 40 CFR 51.302(a) that the FLM making a certification of 
reasonably attributable visibility impairment must offer an opportunity 
to the state(s) containing the identified sources to consult regarding 
the basis for the certification, in person and at least 60 days before 
the FLM makes the certification. This change was added in response to 
comments received that specifically asked for such consultation.
    Fourth, we are not finalizing the proposed changes to 40 CFR 
51.308(c), for the following reasons. Because we are finalizing a 3-
year, fixed deadline for state response to a certification of 
reasonably attributable visibility impairment, the first part of the 
proposed provision (regarding the need to respond as part of an 
upcoming, otherwise due SIP revision) no longer applies. As to the 
second part of the proposed provision (regarding monitoring to assess 
reasonably attributable visibility impairment), we now realize this 
aspect is adequately covered by 40 CFR 51.308(f)(4) and that 
duplication of requirements in different subsections would only cause 
confusion. Therefore, 40 CFR 51.308(c) will remain unchanged from the 
1999 RHR.

J. Consistency Revisions Related To Permitting of New and Modified 
Major Sources

1. Summary of Proposal
    Proposed changes to 40 CFR 51.307, New source review, were limited 
to a few proposed changes to maintain consistency with other sections 
of the RHR and with the CAA. These changes were minor and therefore 
will not be repeated here.
2. Comments and Responses
    There were no significant comments received on the proposed changes 
to this subsection.
3. Final Rule
    Changes to 40 CFR 51.307 are being finalized as proposed. The EPA 
does wish to emphasize the requirement for FLM consultation during the 
new source review permitting process. As discussed in the preamble for 
the proposal, 40 CFR 51.307(a) requires FLM consultation for any new 
major source or major modification that would be constructed in an area 
designated attainment or unclassifiable that may affect visibility in 
any Federal Class I

[[Page 3116]]

area. FLM consultation is also required under 40 CFR 51.307(b)(2) for 
any major source or major modification that proposes to locate in a 
nonattainment area that may affect visibility in any mandatory Federal 
Class I area. Two EPA guidance documents interpret this consultation 
requirement, particularly with regard to evaluating whether a proposed 
new major source or major modification may affect visibility in a 
Federal Class I area.\126\ The EPA regional offices can provide 
additional assistance to states in ensuring that their permitting 
programs meet the regulations and that the appropriate consultation is 
being conducted for affected permits.
---------------------------------------------------------------------------

    \126\ Notification to Federal Land Manager Under Section 165(d) 
of the Clean Air Act, memo from David G. Hawkins, EPA Assistant 
Administrator for Air, Noise, and Radiation to EPA's Regional 
Administrators, March 19, 1979; 1990 New Source Review Workshop 
Manual, Chapter E, Section III A. Source Applicability.
---------------------------------------------------------------------------

K. Changes to FLM Consultation Requirements

1. Summary of Proposal
    As discussed in the proposed rule, state consultation with FLMs is 
a critical part of the development of quality SIPs. We proposed not 
only to apply the FLM consultation requirements of 40 CFR 51.308(i)(2) 
to progress reports that are not SIP revisions, but to make further 
edits to this subsection to support such consultations. The proposed 
changes were motivated by a concern that the 1999 RHR's requirement for 
consultation at least 60 days prior to a public hearing may not result 
in a state offering an in-person consultation meeting sufficiently 
early in the state's planning process to meaningfully inform the 
state's development of the long-term strategy. We proposed to add a 
requirement that such consultation on SIPs and progress reports occur 
early enough to allow the state time for full consideration of FLM 
input, but no fewer than 60 days prior to a public hearing or other 
public comment opportunity. A consultation opportunity that takes place 
no less than 120 days prior to a public hearing or other public comment 
opportunity would then be deemed to have been ``early enough.''
2. Comments and Responses
    Overall, the comments were split with many favoring any enhanced 
FLM participation in regional haze planning, while most states 
generally disfavored enhanced participation.
    Regarding comments specific to the proposed changes to 40 CFR 
51.308(i)(2), states were split in supporting or opposing the inclusion 
of a reference using the phrase ``early enough.'' Some commenters said 
the criteria were not clear and asked for clarity on what would be 
needed to satisfy the requirement. In addition, many states and 
industry said the current 60-day period is long enough for SIPs, and 
that a longer period could delay their submission.
    For progress reports, several state and industry commenters 
indicated that the 60-day period described in the 1999 RHR is 
sufficient, or that FLMs should not be consulted on progress reports at 
all if they are no longer required to be SIP revisions. A main concern 
was that anything more than a 60-day period would conflict with the 
proposed requirement in 40 CFR 51.308(g)(3) to assess current 
conditions based on the IMPROVE data available 6 months before the 
progress report due date. As discussed earlier in this document, this 
requirement under 40 CFR 51.308(g)(3) is being finalized as proposed. 
The EPA agrees that a requirement to consult with FLMs on progress 
reports more than 60 days prior to opening a public comment period may 
interfere with the revised provisions in 40 CFR 51.308(g)(3) and is 
therefore finalizing the 60-day requirement without referring to 
consultation being ``early enough'' and without referring to the 120-
day point in the process.
    Finally, some multi-state organization commenters asked for 
confirmation that state and FLM participation in the RPO process would 
continue to meet the consultation requirement. The EPA does not agree 
that such participation would suffice for consultation because being 
informed of the technical work performed by the multi-state 
organizations is not the same as the FLMs being substantively involved 
in regulatory decisions a state makes on what controls to require based 
on that work (i.e., the decisions on the long-term strategy on which 
public comment will be sought prior to submission to the EPA in the 
form of a SIP revision). Furthermore, the objective of these provisions 
is not to achieve FLM consultation with states on setting RPGs, since 
that process is largely mechanical in nature because RPGs are to be 
based on the long-term strategy and do not involve any additional 
policy decisions. We note that a standing invitation for FLM 
participation in the work performed by multi-state organizations may be 
part of the procedures that a SIP provides for continuing consultation 
between the state and the FLM, as required by 40 CFR 51.308(i)(4).
    For a more thorough discussion of the comments on FLM consultation 
requirements, please see the RTC document available in the docket for 
this rulemaking.
3. Final Rule
    After consideration of public comments, we are finalizing the 
revisions to 40 CFR 51.308(i)(2) with changes from proposal. The 
proposed requirement for consultation no fewer than 60 days prior to a 
public hearing or other public comment opportunity (with a consultation 
opportunity that takes place no less than 120 days prior to a public 
hearing or other public comment opportunity being deemed ``early 
enough'') is being finalized for SIP revisions. For progress reports 
(which, as discussed elsewhere in this document, will no longer be 
subject to the formalities of a SIP revision), the EPA is finalizing a 
requirement for consultation no fewer than 60 days prior to a public 
hearing or other public comment opportunity, with no reference to the 
consultation opportunity being ``early enough.'' We are also finalizing 
somewhat different wording regarding the purpose of the consultation on 
SIP revisions, to convey the idea that consultation that takes place 
via an in-person meeting 60 to 120 days prior to a public hearing or 
comment opportunity will be about decisions that are about to be made 
by the state on its long-term strategy rather than about the plan for 
the technical analysis that informs these decisions, because by that 
time the technical analysis will have already been largely 
completed.\127\ The final wording on the purpose of the consultation 
also emphasizes the content of the long-term strategy rather than the 
setting of the RPGs, consistent with the concept that the RPGs are a 
reflection of the requirements of the long-term strategy.
---------------------------------------------------------------------------

    \127\ We expect that the FLM would have already provided input 
into the planning of the technical analysis including steps to 
gather information to be analyzed, as part of the ongoing 
consultation required under 40 CFR 51.308(h)(4) and as part of FLM 
participation in multi-state planning groups.
---------------------------------------------------------------------------

L. Extension of Next Regional Haze SIP Deadline From 2018 to 2021

1. Summary of Proposal
    The EPA proposed to revise 40 CFR 51.308(f) to move the deadline 
for the submission of the next periodic comprehensive SIP revisions 
from July 31, 2018, to July 31, 2021, with states retaining the option 
of submitting their SIP revisions before July 31, 2021. We proposed to 
leave the end date for the second implementation period at 2028,

[[Page 3117]]

regardless of when SIP revisions are submitted. The proposed change was 
to be a one-time schedule adjustment such that the due dates for 
periodic comprehensive SIP revisions for the third and subsequent 
planning periods would still be due on July 31, 2028, and every 10 
years thereafter. The EPA proposed this extension to allow states to 
coordinate regional haze planning with other regulatory programs, 
including but not limited to the Mercury and Air Toxics Standards,\128\ 
the 2010 1-hour SO2 NAAQS,\129\ the 2012 annual 
PM2.5 NAAQS \130\ and the Clean Power Plan,\131\ with the 
further expectation that this cross-program coordination would lead to 
better overall policies and enhanced environmental protection.
---------------------------------------------------------------------------

    \128\ 77 FR 9304, February 16, 2012.
    \129\ 75 FR 35520, June 22, 2010.
    \130\ 78 FR 3086, January 15, 2013.
    \131\ 80 FR 64662, October 23, 2015. The Clean Power Plan was 
stayed by the Supreme Court for the duration of litigation. Order in 
Pending Case, West Virginia v. EPA, No. 15A773 (February 9, 2016). 
As a result, states have no compliance obligations with respect to 
the Clean Power Plan at this time.
---------------------------------------------------------------------------

2. Comments and Reponses
    Many commenters, especially state air agencies, expressed support 
for this extension, while other commenters opposed it. A primary 
concern from the latter group of commenters was that, given the fact 
that many initial regional haze SIPs were submitted late (in some 
cases, well into the first implementation period), this pattern was 
likely to continue and many periodic comprehensive SIP revisions would 
not be submitted by July 31, 2021, which would leave even less time 
during the second implementation period for any emission reductions 
necessary for reasonable progress to occur. One commenter stated that 
the 2021 date would be workable provided EPA acts promptly on each 
state's periodic comprehensive SIP revision, and that EPA should 
indicate now that it will make prompt findings of nonsubmittal or 
substantial inadequacy when the time comes.
    As a general matter, making findings of nonsubmittal or substantial 
inadequacy are well within the EPA's authority. While we recognize the 
commenter's concern regarding the timing of SIP submissions, we expect 
that the length of the second implementation period will be sufficient 
to secure the emission reductions necessary for reasonable progress. 
The EPA anticipates that the experience states and the EPA have gained 
from the first round of regional haze planning will result in a more 
efficient process of SIP submission and review moving forward. 
Furthermore, the EPA has clarified in the final rule that whether or 
not a control measure can be installed and become operational before 
the end of the planning period is not a factor in determining whether 
that measure is necessary to achieve reasonable progress. Thus, the 
length of the implementation period should not be a barrier to 
achieving the emission reductions identified by the reasonable progress 
analysis. Finally, this rule change grants states additional time up 
front (before 2021) for regional haze planning and analysis and thus 
makes it more likely they will submit their SIP revisions for the 
second implementation period either on or ahead of schedule.
    Some commenters contended that the EPA's rationales do not justify 
the proposed extension, and that giving states an additional 3 years to 
coordinate their planning would frustrate Congress's policy goals and 
impair human health. One commenter said that the EPA should evaluate 
the public health impacts of its proposal to delay the SIP deadline to 
2021. We disagree with these comments. As we explained at proposal, the 
RHR requires states to include the impacts of other regulatory programs 
when developing their regional haze SIPs. Many industries, including 
the utility sector, are currently in the midst of developing mid- to 
long-term plans that will govern how they navigate the numerous recent 
additions to the regulatory landscape that include, but are not limited 
to, the programs discussed in the proposal and mentioned previously 
(i.e., the Mercury and Air Toxics Standards,\132\ the 2010 1-hour 
SO2 NAAQS,\133\ the 2012 annual PM2.5 NAAQS \134\ 
and the Clean Power Plan).
---------------------------------------------------------------------------

    \132\ 77 FR 9304, February 16, 2012.
    \133\ 75 FR 35520, June 22, 2010.
    \134\ 78 FR 3086, January 15, 2013.
---------------------------------------------------------------------------

    Decisions that states and regulated entities make in response to 
one program may affect the options available for addressing their 
regional haze obligations, and vice versa. Providing time for regulated 
entities to coordinate their planning will allow them to design 
pollution control strategies that make efficient and effective use of 
their resources over the long term. Congress's goal of attaining 
natural visibility conditions will not be achieved in the next 
implementation period--it is necessarily a longer-term effort that will 
require states and regulated entities to make careful, considered 
decisions about how to balance the requirement to achieve sustained and 
sustainable visibility improvement moving forward with their business, 
regulatory and other priorities. Additionally, with the extension of 
the due date for the second implementation period SIPs, we are 
maintaining 2028 as the end date of the implementation period. We thus 
disagree that providing states 3 additional years to coordinate 
planning is inconsistent with continuing to make reasonable progress 
towards the ultimate goal of natural visibility conditions. We also 
disagree that providing 3 additional years will seriously undermine the 
goal of coordinated, regional planning among states. While we are aware 
that some states in the eastern U.S. are considering submitting SIPs 
before July 31, 2021, these states are coordinating among themselves on 
their technical analyses and they have not indicated that the extension 
will obstruct their coordination with other states.
    Although Congress did not establish an explicit role for health 
considerations in the regional haze program, reductions of visibility-
impairing pollutants also have important health related co-benefits. 
However, because the purpose of the regional haze program is improving 
visibility in Class I areas, we disagree that the EPA should evaluate 
the human health impacts of moving the deadline for regional haze SIP 
submissions from 2018 to 2021. Importantly, the emission reductions 
achieved in the first implementation period will continue to be in 
effect, and emissions will continue to be addressed during this period 
under the existing structure of federal, state and local clean air 
programs. Insofar as states and sources were already planning to 
undertake emission control projects in response to other regulatory 
requirements, the timing of these projects will be unaffected by the 
change in the SIP due date in the regional haze program. Furthermore, 
states are not required to wait until 2021 to submit their regional 
haze SIP revisions for the second implementation period, although they 
may choose to do so.
    One commenter asserted that EPA's proposal to extend the deadline 
for submission of regional haze SIPs for the second implementation 
period violates the plain language of the section 169B(e)(2) of the 
CAA. The commenter argues that this statutory provision requires EPA to 
mandate that states submit regional haze SIP revisions within 12 months 
of promulgating RHR revisions under section 169A. We disagree. Section 
169B(e)(2) states that ``[a]ny regulations promulgated under section 
[169A] of this title pursuant to this subsection shall require affected

[[Page 3118]]

States to revise within 12 months their implementation plans under 
section [110].'' (emphasis added). The subsection at issue, 169B(e)(1), 
requires EPA to promulgate regional haze regulations within 18 months 
of receiving the report required of Visibility Transport Commissions 
under 169B(d)(2). This report was a one-time requirement intended to 
inform EPA's yet-to-be-promulgated regulations. Thus, section 
169B(e)(1) clearly expresses Congress's intent to establish a timetable 
for the EPA's initial regional haze rulemaking in order to ensure that 
the regulations would be promulgated in a timely fashion and would be 
informed by the studies and report required under 169B(a)(1) and 
(d)(2), respectively. Section 169B(e)(2) states that regulations 
promulgated pursuant to (e)(1)--which addresses only EPA's obligation 
to undertake that initial regional haze rulemaking--must require states 
to submit SIP revisions within 12 months. We disagree with the 
commenter's assertion that Congress intended this 12-month deadline to 
apply in the case of subsequent rule revisions, as subsection (e) 
describes a one-time process of research, reports and rulemaking to get 
the regional haze program off the ground. Neither 169(e)(1) nor (e)(2) 
contains any indication that Congress intended this specific timeline 
to apply for additional, future rulemakings.
    Another commenter said that in lieu of formally extending the 
deadline, the Agency should consider granting an administrative waiver 
to a state that affirmatively shows that a delay in submitting its 
periodic comprehensive SIP revisions is warranted. The EPA does not 
believe the additional effort required on the part of a state and the 
EPA would be worthwhile for such an undertaking because many states 
have good reason to coordinate their planning for their periodic 
comprehensive SIP revisions with that for other regulatory requirements 
and programs. A waiver process would thus add considerable 
administrative burden with minimal benefit, as the EPA would be likely 
to grant most or all of the waiver requests based on this need to 
coordinate planning.
3. Final Rule
    The EPA is finalizing this one-time deadline extension with no 
changes from proposal.

M. Changes to Scheduling of Regional Haze Progress Reports

1. Summary of Proposal
    The EPA proposed to revise the requirements in 40 CFR 51.308(g) and 
(h) regarding the timing of submission of reports evaluating progress 
towards the natural visibility goal. The 1999 RHR required states to 
submit regional haze progress reports every 5 years, with the first 
progress report due 5 years after submission of the first periodic 
comprehensive SIP revisions. Because states submitted these first SIP 
revisions on dates spread across several years, many of the due dates 
for progress reports currently do not fall mid-way between the due 
dates for periodic comprehensive SIP revisions, as the EPA initially 
envisioned. Looking forward, continued operation of the 1999 RHR would 
in many cases require a progress report shortly before or shortly after 
a periodic comprehensive SIP revision, at which time it could not be 
expected to have much utility as a mid-course review of environmental 
progress or much incremental informational value for the public 
compared to the data contained in that SIP revision.
    Complementing the revisions to 40 CFR 51.308(f) regarding the 
deadlines for submittal of periodic comprehensive revisions, we 
proposed to revise 40 CFR 51.308(g) and (h) such that the second and 
subsequent progress reports would be due by January 31, 2025, July 31, 
2033, and every 10 years thereafter, placing one progress report mid-
way between the due dates for periodic comprehensive SIP revisions. As 
we explained, this timing provides a balance between allowing the 
implementation of the most recent SIP revision to proceed long enough 
for a review to be possible and worthwhile, and having enough time 
remaining before the next comprehensive SIP revision for state action 
to make changes in its rules or implementation efforts, if necessary, 
separately from the actions in that next SIP.
    As explained in the proposal, the EPA no longer believes a progress 
report is useful at or near the time of submission of a periodic 
comprehensive SIP revision, since in practical terms a progress report 
provides little additional information beyond that required in a 
periodic comprehensive SIP revision (with the exception of the 1999 
RHR's requirement that a progress report include information on the 
trend in visibility over the whole period since the baseline period of 
2000-2004). In order to substantially reduce administrative burdens and 
make progress reports more useful to the public with no attendant 
reduction in environmental protection, we proposed to limit the 
requirement for separate progress reports to the one due mid-way 
between periodic comprehensive SIP revisions and to add to the 
requirement for periodic comprehensive SIP revisions a requirement to 
include the visibility trend information that the 1999 RHR previously 
required exclusively in progress reports.
2. Comments and Responses
    Commenters generally supported the change to progress report 
scheduling such that due dates would fall mid-way between those of 
periodic comprehensive SIP revisions, though some comments recommended 
that a periodic SIP revision be explicitly required to include all the 
required progress report elements listed in 40 CFR 51.308(g) of the 
1999 RHR and in particular element (g)(6), which requires an assessment 
of whether the current SIP is sufficient to meet all established RPGs. 
There are seven listed progress report elements in the 1999 RHR and 
eight listed elements in the revised final rule. The subjects of the 
first five of the elements are the same in the two versions of the 
rule, and we proposed and are finalizing a requirement that each 
periodic SIP revision address these five elements. We are not requiring 
periodic SIP revisions to assess whether the SIP is sufficient to meet 
all established RPGs (element (g)(6) in the 1999 RHR and the revised 
final rule). Given that the SIP is being revised, there would be no 
utility in assessing whether the previous terms of the SIP for the 
previous implementation period were sufficient to meet the progress 
goals for the previous period. Also, since the new SIP revision will 
contain new progress goals for the end of the currently applicable 
implementation period and these goals will be calculated to reflect the 
new measures in that SIP revision and previously adopted measures, it 
necessarily will be that this revised SIP is sufficient to meet the new 
goals. The seventh element of a progress report as listed in the 1999 
RHR (which EPA is eliminating in the revised rule for progress reports 
for the second and subsequent implementation periods for reasons 
described elsewhere in this document) is a review of the monitoring 
strategy. However, periodic SIP revisions are required to address the 
monitoring strategy under 40 CFR 308(f)(6) of the final rule text, so 
no further mention of monitoring strategies is needed. The newly added 
element of a progress report in the revised final rule (now numbered as 
element (g)(8)) is

[[Page 3119]]

the summary of the most recent assessment of a smoke management program 
if any. Our reasons for not requiring periodic SIP revisions to include 
such a summary are given elsewhere in this document.
    Some commenters requested that the progress report due January 1, 
2025, be removed from the rule, given the fact that it would be due 
only 3.5 years after the July 31, 2021, due date of the next periodic 
comprehensive SIP revision. These commenters felt this time period 
prohibitively short and that this information could be better be 
included in the next periodic comprehensive SIP revision due July 31, 
2028. A few commenters asked that EPA entirely remove the requirement 
for progress reports from the regional haze program. As noted 
previously, progress reports are an important tool for states to review 
and potentially make changes in their rules or implementation efforts, 
if necessary. Although the progress report for the second 
implementation period will be due only 3.5 years after the due date of 
the preceding periodic comprehensive SIP revisions, we still believe in 
the usefulness of such a mid-course review. In addition, some states 
have indicated that they intend to submit periodic comprehensive SIP 
revisions closer to the 1999 RHR's July 31, 2018 deadline, so for those 
states substantially more than 3.5 years will have elapsed before the 
progress report becomes due.
3. Final Rule
    The EPA is finalizing these provisions regarding scheduling of 
progress reports, and the aforementioned additional requirement that 
periodic comprehensive SIP revisions include gap-filling visibility 
trend information, with no change from proposal.

N. Changes to the Requirement That Regional Haze Progress Reports Be 
SIP Revisions

1. Summary of Proposal
    We proposed to revise 40 CFR 51.308(g) regarding the requirements 
for the form of progress reports, which under the 1999 RHR were 
required to take the form of SIP revisions that comply with certain 
procedural requirements.\135\ As explained in the proposed rule and 
elsewhere in this document, the EPA originally included the requirement 
for progress reports in the 1999 RHR primarily to ensure that the 
states remain on track between periodic comprehensive SIP revisions. In 
the 1999 RHR, we required progress reports to be in the form of SIP 
revisions that meet the procedural requirements of 40 CFR 51.102 and 
51.103 (which in turn refer to the requirements of Appendix V of 40 CFR 
part 51). Given the requirements for what a state should include in its 
progress report, we anticipated that these submittals would typically 
contain narrative descriptions of such things as current visibility 
conditions and emissions inventories. We did not anticipate that 
progress reports would typically include new or revised emission 
limits.\136\ Although the EPA specifically intended for progress 
reports to involve significantly less effort than a periodic 
comprehensive SIP revision, a state must provide public notice and an 
opportunity for a public hearing for SIP revisions. In addition, they 
must conform to certain administrative procedural requirements, provide 
various administrative material, and must be submitted by an official 
who is authorized by state law to submit a SIP revision.
---------------------------------------------------------------------------

    \135\ These procedural requirements are detailed in 40 CFR 
51.102, 40 CFR 51.103 and Appendix V to Part 51--Criteria for 
Determining the Completeness of Plan Submissions.
    \136\ Under our regulations, if a state were to determine at the 
time of submitting its progress report that its SIP is or may be 
inadequate to ensure reasonable progress due to emissions from 
sources within the state, the state has 1 year in which to submit a 
SIP revision addressing the inadequacy of its plan. 40 CFR 
51.308(h)(4). This SIP revision would contain any required new or 
revised emission limits.
---------------------------------------------------------------------------

    We proposed to revise our regulations so that progress reports need 
not be in the form of SIP revisions, but to require states to consult 
with FLMs and obtain public comment on their progress reports before 
submission to the EPA. We also proposed that the SIP revision due in 
2021 must include a commitment to prepare and submit these progress 
reports to the EPA according to the revised schedule being finalized in 
this rule (see previous section). While these progress reports would be 
acknowledged and assessed by the EPA, our review of these reports would 
not result in a formal approval or disapproval of them. In addition, 
relieving states of the obligation to follow the procedural 
requirements of 40 CFR 51.102 and 51.103 would free up state resources 
for other important environmental planning, given the fact that they 
are resource-intensive. Other advantages to the proposed approach were 
discussed in detail at proposal.
2. Comments and Responses
    Many commenters expressed support, with some suggesting that EPA do 
away with progress reports entirely (similar sentiments were expressed 
in comments on progress report timing; see previously in this 
document). Other commenters opposed eliminating the requirement that 
progress reports take the form of SIP revisions, and expressed that 
review by EPA should at least involve a finding of adequacy or 
inadequacy.
    In response to comments opposing eliminating the requirement that 
progress reports be SIP revisions, the EPA would like to reiterate that 
as part of our review of a progress report, we will follow up with the 
state on any appropriate next steps, and we note again that there are 
additional remedies (such as undertaking a less formal assessment of 
the results of the implementation of the previously submitted SIP) 
available to the EPA in the event a state fails to properly submit a 
progress report.
    Some comments expressed concern that the EPA would use progress 
reports as a basis for a ``SIP call'' and opined that progress reports 
should only provide information for subsequent SIP submittals. It 
should be noted, however, that 40 CFR 51.308(h), which we are not 
revising in any material way, already requires that if a state has 
determined in its progress report that its implementation plan is or 
may be inadequate to ensure reasonable progress due to emissions within 
that state, it must revise its current SIP to address its deficiencies. 
Thus, there is already a mechanism under which states must use the 
information in their progress reports to assess the adequacy of their 
existing SIPs. Additionally, under CAA section 110(k)(5), the EPA has 
the authority to review a SIP and assess the adequacy of that SIP. 
While this authority is discretionary, when and if the EPA does make a 
determination about the adequacy of a regional haze SIP it must do so 
reasonably, and this may require consideration of the information in a 
progress report. Therefore, we are not including in the final rule any 
provision saying that the content of a progress report may not be used 
as part of the basis for a SIP call action.
    We will further consider a suggestion from one commenter that we 
provide a centralized Web site that would inform the public of which 
progress reports are currently available for public comment at the 
state level and the planned end of each comment period.
3. Final Rule
    The EPA is finalizing the proposal to eliminate the requirement 
that progress reports take the form of SIP revisions. The EPA would 
like to emphasize (as explained at proposal) that although progress 
reports will no longer be

[[Page 3120]]

required to take the form of SIP revisions, states will still be 
required to include the required progress report elements listed in 40 
CFR 51.308(g)(1) through 40 CFR 51.308(g)(8), in particular the 
assessment of whether the existing SIP elements are sufficient to 
enable a state to meet all established RPGs for the period covered by 
the most recent periodic SIP revision. We are also retaining the 
requirement that states consult with FLMs and obtain public comment on 
their progress reports before submission to the EPA.\137\ Also, 40 CFR 
51.308(h) will continue to require that at the same time the state is 
required to submit a progress report, it must also take one of four 
listed actions concerning whether the SIP is adequate to achieve 
established goals for visibility improvement, and the state will 
continue to have an obligation to revise its SIP to address any plan 
deficiencies within 1 year of submission of a determination that the 
SIP is or may be inadequate.
---------------------------------------------------------------------------

    \137\ We discuss the timing for consultation elsewhere in this 
preamble.
---------------------------------------------------------------------------

O. Changes to Requirements Related to the Grand Canyon Visibility 
Transport Commission

1. Summary of Proposal
    As noted in the proposal, 40 CFR 51.309 has limited applicability 
going forward because its provisions apply only to 16 Class I areas 
covered by the Grand Canyon Visibility Transport Commission Report, 
only to three states that chose to rely on the special provisions in 
this section and only to SIPs for the first regional haze 
implementation period (i.e., through 2018). However, we proposed 
certain conforming revisions to avoid confusion going forward, 
including the following:
     Revising 40 CFR 51.309(d)(4)(v) to correctly refer to the 
new 40 CFR 51.302(b) (in lieu of (e), which no longer exists in the 
proposed 40 CFR 51.302) and to delete the reference to BART since it 
does not appear in 40 CFR 51.302(b).
     Changing the title of 40 CFR 51.309(c)(10), Periodic 
implementation plan revisions, to include ``and progress reports'' at 
the end, to complement the revisions that will no longer require 
progress reports be considered SIP revisions.
     Revising 40 CFR 51.309(c)(10) to preserve the 1999 RHR's 
requirement that the progress reports due in 2013 take the form of SIP 
revisions, but direct the reader to the provisions of 40 CFR 51.308(g) 
for subsequent progress reports.
     Revising 40 CFR 51.309(c)(10)(iv) to indicate that 
subsequent progress reports are subject to the requirements of 40 CFR 
51.308(h) regarding determinations of adequacy of existing SIPs.
     Revising 40 CFR 51.309(g)(2)(iii) to correct a 
typographical error.
2. Comments and Responses
    Few comments were received on the proposed revisions to 40 CFR 
51.309. Of those, most concerned fire issues, and this subject matter 
is treated elsewhere in this document. One commenter requested 
clarification on what happens to states participating in the GCVTC 
after 2018, and in response the EPA would like to clarify that all 
measures and obligations contained in a SIP approved pursuant to 40 CFR 
51.309 must continue to be implemented unless the SIP itself provides 
for that measure or obligation to sunset, that the revised provisions 
of 40 CFR 51.309 will apply to any SIP revision that would revise a SIP 
provision that was part of the basis of EPA initially approving the SIP 
as meeting the requirements of the 1999 RHR's 40 CFR 51.309 and that 
future periodic comprehensive SIP revisions and progress reports from 
these states will be subject to the requirements of 40 CFR 51.308(f) 
and (g), respectively.
3. Final Rule
    All revisions to 40 CFR 51.309 are being finalized without change 
from proposal.

V. Environmental Justice Considerations

    The EPA believes this action will not have disproportionately high 
and adverse human health, well-being or environmental effects on 
minority, low-income or indigenous populations because it will not 
negatively affect the level of protection provided to human health, 
well-being or the environment under the CAA's visibility protection 
program. These revisions to the RHR alter procedural and timing aspects 
of the SIP requirements for visibility protection but do not 
substantively change the requirement that SIPs provide for reasonable 
progress towards the goal of natural visibility conditions. These SIP 
requirements are designed to protect all segments of the general 
population.
    The EPA acknowledges that the delay in submitting SIP revisions 
from 2018 to 2021 might, but will not necessarily, affect the schedule 
on which sources must comply with any new requirements. One commenter 
said that any such delay in reducing emissions is likely to 
disproportionately impact children, communities of color and the 
economically disadvantaged. However, because neither the CAA nor the 
1999 RHR set specific deadlines for when sources must comply with any 
new requirements in a state's next periodic comprehensive SIP revision, 
states have substantial discretion in establishing reasonable 
compliance deadlines for measures in their SIPs. Given this, we expect 
to see a range of compliance deadlines in the next round of regional 
haze SIPs from early in the second implementation period to 2028, 
depending on the types of measures adopted, and this would have 
occurred regardless of whether these changes had been finalized. Thus, 
the EPA believes the delay in the periodic comprehensive SIP revision 
submission deadline from 2018 to 2021 will not meaningfully reduce the 
overall progress towards better visibility made by the end of 2028 and 
will not meaningfully adversely affect environmental protection for any 
segments of the population. Furthermore, by reducing uncertainty about 
the requirements of the RHR and in some regards making those 
requirements more protective, we believe this action is likely to 
improve public health protection.

VI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is a significant regulatory action that was submitted 
to the Office of Management and Budget (OMB) for review. Any changes 
made in response to OMB recommendations have been documented in the 
docket.

B. Paperwork Reduction Act (PRA)

    The information collection activities in this final rule have been 
submitted for approval to the OMB under the PRA. The ICR document that 
the EPA prepared has been assigned the EPA ICR number 2540.02. A copy 
of the ICR supporting statement is available in the docket for this 
rule, and it is briefly summarized here.
    The EPA is finalizing revisions to requirements for state regional 
haze planning to change the requirements that must be met by states in 
developing regional haze SIPs, periodic comprehensive SIP revisions, 
and progress reports for regional haze. The main intended effects of 
this rulemaking are to provide states with additional time to submit 
regional haze plans for the second implementation period and

[[Page 3121]]

to provide states with an improved schedule and process for progress 
report submission. Further reductions in burden on states for the 
second planning period include removal of the requirement for progress 
reports to be SIP revisions, clarifying that states are not required to 
project emissions inventories as part of preparing a progress report, 
and relieving the state of the need to review its visibility monitoring 
strategy within the context of the progress report. With all of these 
changes considered, the overall burden on states would represent a 
reduction compared to what would otherwise occur if the provisions of 
the 1999 RHR were to stay in place. However, we agree with public 
comments received on the ICR for the proposed rule indicating that the 
EPA's previous estimates of burden for the 1999 RHR, as well as 
estimates of burden for the proposed rule, did not accurately reflect 
the level of effort required to draft SIPs and progress reports. 
Although at proposal, the total estimated burden for the applicable 
period of this ICR (i.e., 2016-2019) was estimated to be reduced from 
10,307 hours (per year) to 5,974 hours (per year), and total estimated 
cost was expected to be reduced from $510,498 (per year) to $295,876 
(per year), taking into account the information submitted by the 
commenters, the EPA now estimates burden under the final rule for the 
applicable period of 2016-2019 to be 13,310 hours (per year) and total 
estimated cost to be $659,245 (per year). Please note that the EPA 
believes the final rule will allow for a reduction in effort compared 
to the 1999 RHR. Thus, if the SIP development and other were undertaken 
under the 1999 RHR, the costs would be higher than with this final 
rule. The apparent increase in estimated hours and cost is related to 
updates of prior estimates in light of more accurate information. 
Despite this, the EPA projects that the total estimated burden and cost 
associated with the final rule are less than would be required if the 
rule revisions were not made. The revisions, for example, extend 
planning deadlines, reduce the number of SIP submissions to the EPA, 
relieve states of the need to supply progress reports in the form of 
formal SIP revisions, and relieve the state of the need to review its 
visibility monitoring strategy within the context of the progress 
report. In addition, in accordance with OMB guidance, these numbers 
reflect the average burden on states per year over the next 3 years 
only. This burden will vary from year to year, and due to the nature of 
an average, some states may be above the average while other states may 
be below the average. The ``per-year'' numbers provided here are the 3-
year averages, and these 3-year averages will also vary. For example, 
the prior 3-year period (associated with the prior ICR) was not an 
active SIP development period, and therefore burden on states was 
relatively low in comparison to the 3-year period associated with this 
ICR. During this 3-year period states will be taking steps to prepare 
their next SIPs. SIP development and adoption will continue into the 
following 3-year period (approximately 2019-2022), and then subside 
until the next SIP is due in 2028, resulting in a reduced burden 
compared to the estimates reflected here. For more information and a 
summary and response to comments received on the proposed rule ICR, 
please see the Information Collection Request Supporting Statement for 
EPA ICR Number 2540.02. ICR for Final Revisions to the Regional Haze 
Regulations, in the docket for this rule. All states are required to 
submit regional haze SIPs and progress reports under this rule.
    Respondents/affected entities: All state air agencies.
    Respondent's obligation to respond: Mandatory, in accordance with 
the provisions of the 1999 RHR.
    Estimated number of respondents: 52: 50 states, District of 
Columbia and U.S. Virgin Islands.
    Frequency of response: Approximately every 10 years (SIP) and 
approximately every 10 years (progress report).
    Total estimated burden: 13,310 hours (per year). Burden is defined 
at 5 CFR 1320.3(b).
    Total estimated cost: $659,245 (per year), includes $0 annualized 
capital or operation & maintenance costs.
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for the 
EPA's regulations in 40 CFR are listed in 40 CFR part 9.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. This 
action will not impose any requirements on small entities. Entities 
potentially affected directly by these rule revisions include state 
governments, and for the purposes of the RFA, state governments are not 
considered small governments. Tribes may choose to follow the 
provisions of the RHR but are not required to do so. Other types of 
small entities are not directly subject to the requirements of this 
rule.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in 
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect 
small governments. This action imposes no enforceable duty on any 
state, local or tribal governments or the private sector.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action does not have tribal implications as specified in 
Executive Order 13175. It does not have a substantial direct effect on 
one or more Indian tribes. Furthermore, these regulation revisions do 
not affect the relationship or distribution of power and 
responsibilities between the federal government and Indian tribes. The 
CAA and the TAR establish the relationship of the federal government 
and tribes in characterizing air quality and developing plans to 
protect visibility in Class I areas, and these revisions to the 
regulations do nothing to modify that relationship. Thus, Executive 
Order 13175 does not apply to this action.
    Although Executive Order 13175 does not apply to this action, the 
EPA held public hearings attended by members of tribes and separate 
meetings with tribal representatives to discuss the revisions proposed 
in this action. The EPA also provided an opportunity for all interested 
parties to provide oral or written comments on potential concepts for 
the EPA to address during the rule revision process. Summaries of these 
meetings are included in the docket for this rule. The EPA also offered 
to consult with any tribal government to discuss this proposal. A copy 
of this offer for consultation can be found in the docket for this 
rulemaking. No tribes requested consultation. One tribal organization 
submitted comments, which generally endorsed the proposed revisions. 
However, this commenter said that this action does have implications to 
tribes and that the EPA must develop an accountability process to 
ensure meaningful and timely input to states as they implement the 
revised

[[Page 3122]]

requirements of the RHR. We acknowledge this comment but we do not find 
it to contain a basis for changing our finding that Executive Order 
13175 does not apply to this action. See also Section III.B.5 of this 
document for further discussion regarding the role of tribes in 
visibility protection.

G. Executive Order 13045: Protection of Children From Environmental 
Health and Safety Risks

    The EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that concern environmental health or safety risks 
that the EPA has reason to believe may disproportionately affect 
children, per the definition of ``covered regulatory action'' in 
section 2-202 of the Executive Order. This action is not subject to 
Executive Order 13045 because it does not concern an environmental 
health risk or safety risk.

H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution or Use

    This action is not a ``significant energy action'' because it is 
not likely to have a significant adverse effect on the supply, 
distribution or use of energy.

I. National Technology Transfer and Advancement Act

    This rulemaking does not involve technical standards.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    The EPA believes that this action may not have disproportionately 
high and adverse effects on minority populations, low-income 
populations and/or indigenous peoples, as specified in Executive Order 
12898.\138\ The results of our evaluation are contained in Section V of 
this document.
---------------------------------------------------------------------------

    \138\ 59 FR 7629 (February 16, 1994).
---------------------------------------------------------------------------

K. Congressional Review Act (CRA)

    This action is subject to the CRA, and the EPA will submit a rule 
report to each House of the Congress and to the Comptroller General of 
the U.S. This action is not a ``major rule'' as defined by 5 U.S.C. 
804(2).

VII. Statutory Authority

    The statutory authority for this action is provided by 42 U.S.C. 
7403, 7407, 7410 and 7601.

List of Subjects

40 CFR Part 51

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Nitrogen dioxide, Particulate matter, Sulfur 
oxides, Transportation, Volatile organic compounds.

40 CFR Part 52

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Incorporation by reference, Nitrogen dioxide, 
Particulate matter, Sulfur oxides, Transportation, Volatile organic 
compounds.

    Dated: December 14, 2016.
Gina McCarthy,
Administrator.

    For the reasons stated in the preamble, part 51 and part 52 of 
chapter I of title 40 of the Code of Federal Regulations are amended as 
follows:

PART 51--REQUIREMENTS FOR PREPARATION, ADOPTION, AND SUBMITTAL OF 
IMPLEMENTATION PLANS

0
1. The authority citation for part 51 continues to read as follows:

    Authority: 23 U.S.C. 101; 42 U.S.C. 7401-7671q.

Subpart P--Protection of Visibility

0
2. Section 51.300 is amended by revising paragraph (b) to read as 
follows:


Sec.  51.300  Purpose and applicability.

* * * * *
    (b) Applicability The provisions of this subpart are applicable to 
all States as defined in section 302(d) of the Clean Air Act (CAA) 
except Guam, Puerto Rico, American Samoa, and the Northern Mariana 
Islands.

0
3. Section 51.301 is amended by:
0
a. Adding the definitions in alphabetical order for ``Baseline 
visibility condition'', ``Clearest days'', and ``Current visibility 
condition'';
0
b. Revising the definition of ``Deciview'';
0
c. Adding the definitions in alphabetical order for ``Deciview index'' 
and ``End of the applicable implementation period'';
0
d. Revising the definition of ``Least impaired days'', ``Mandatory 
Class I Federal Area'', ``Most impaired days'', and ``Natural 
conditions'';
0
e. Adding the definitions in alphabetical order for ``Natural 
visibility'', ``Natural visibility condition'', and ``Prescribed 
fire'';
0
f. Revising the definitions of ``Reasonably attributable'' and 
``Regional haze'';
0
g. Adding the definition in alphabetical order for ``Visibility'';
0
h. Removing the definition of ``Visibility impairment'';
0
i. Adding the definition of ``Visibility impairment or anthropogenic 
visibility impairment''; and,
0
j. Adding the definitions in alphabetical order for ``Wildfire'' and 
``Wildland''.
    The revisions and additions read as follows:


Sec.  51.301  Definitions.

* * * * *
    Baseline visibility condition means the average of the five annual 
averages of the individual values of daily visibility for the period 
2000-2004 unique to each Class I area for either the most impaired days 
or the clearest days.
* * * * *
    Clearest days means the twenty percent of monitored days in a 
calendar year with the lowest values of the deciview index.
    Current visibility condition means the average of the five annual 
averages of individual values of daily visibility for the most recent 
period for which data are available unique to each Class I area for 
either the most impaired days or the clearest days.
    Deciview is the unit of measurement on the deciview index scale for 
quantifying in a standard manner human perceptions of visibility.
    Deciview index means a value for a day that is derived from 
calculated or measured light extinction, such that uniform increments 
of the index correspond to uniform incremental changes in perception 
across the entire range of conditions, from pristine to very obscured. 
The deciview index is calculated based on the following equation (for 
the purposes of calculating deciview using IMPROVE data, the 
atmospheric light extinction coefficient must be calculated from 
aerosol measurements and an estimate of Rayleigh scattering):
    Deciview index = 10 ln (bext/10 Mm-1).
    bext = the atmospheric light extinction coefficient, 
expressed in inverse megameters (Mm-1).
    End of the applicable implementation period means December 31 of 
the year in which the next periodic comprehensive implementation plan 
revision is due under Sec.  51.308(f).
* * * * *
    Least impaired days means the twenty percent of monitored days in a 
calendar

[[Page 3123]]

year with the lowest amounts of visibility impairment.
* * * * *
    Mandatory Class I Federal Area or Mandatory Federal Class I Area 
means any area identified in part 81, subpart D of this title.
    Most impaired days means the twenty percent of monitored days in a 
calendar year with the highest amounts of anthropogenic visibility 
impairment.
    Natural conditions reflect naturally occurring phenomena that 
reduce visibility as measured in terms of light extinction, visual 
range, contrast, or coloration, and may refer to the conditions on a 
single day or a set of days. These phenomena include, but are not 
limited to, humidity, fire events, dust storms, volcanic activity, and 
biogenic emissions from soils and trees. These phenomena may be near or 
far from a Class I area and may be outside the United States.
    Natural visibility means visibility (contrast, coloration, and 
texture) on a day or days that would have existed under natural 
conditions. Natural visibility varies with time and location, is 
estimated or inferred rather than directly measured, and may have long-
term trends due to long-term trends in natural conditions.
    Natural visibility condition means the average of individual values 
of daily natural visibility unique to each Class I area for either the 
most impaired days or the clearest days.
* * * * *
    Prescribed fire means any fire intentionally ignited by management 
actions in accordance with applicable laws, policies, and regulations 
to meet specific land or resource management objectives.
    Reasonably attributable means attributable by visual observation or 
any other appropriate technique.
* * * * *
    Regional haze means visibility impairment that is caused by the 
emission of air pollutants from numerous anthropogenic sources located 
over a wide geographic area. Such sources include, but are not limited 
to, major and minor stationary sources, mobile sources, and area 
sources.
* * * * *
    Visibility means the degree of perceived clarity when viewing 
objects at a distance. Visibility includes perceived changes in 
contrast, coloration, and texture elements in a scene.
    Visibility impairment or anthropogenic visibility impairment means 
any humanly perceptible difference due to air pollution from 
anthropogenic sources between actual visibility and natural visibility 
on one or more days. Because natural visibility can only be estimated 
or inferred, visibility impairment also is estimated or inferred rather 
than directly measured.
* * * * *
    Wildfire means any fire started by an unplanned ignition caused by 
lightning; volcanoes; other acts of nature; unauthorized activity; or 
accidental, human-caused actions, or a prescribed fire that has 
developed into a wildfire. A wildfire that predominantly occurs on 
wildland is a natural event.
    Wildland means an area in which human activity and development is 
essentially non-existent, except for roads, railroads, power lines, and 
similar transportation facilities. Structures, if any, are widely 
scattered.

0
4. Revise Sec.  51.302 to read as follows:


Sec.  51.302  Reasonably attributable visibility impairment.

    (a) The affected Federal Land Manager may certify, at any time, 
that there exists reasonably attributable visibility impairment in any 
mandatory Class I Federal area and identify which single source or 
small number of sources is responsible for such impairment. The 
affected Federal Land Manager will provide the certification to the 
State in which the impairment occurs and the State(s) in which the 
source(s) is located. The affected Federal Land Manager shall provide 
the State(s) in which the source(s) is located an opportunity to 
consult on the basis of the planned certification, in person and at 
least 60 days prior to providing the certification to the State(s).
    (b) The State(s) in which the source(s) is located shall revise its 
regional haze implementation plan, in accordance with the schedule set 
forth in paragraph (d) of this section, to include for each source or 
small number of sources that the Federal Land Manager has identified in 
whole or in part for reasonably attributable visibility impairment as 
part of a certification under paragraph (a) of this section:
    (1) A determination, based on the factors set forth in Sec.  
51.308(f)(2), of the control measures, if any, that are necessary with 
respect to the source or sources in order for the plan to make 
reasonable progress toward natural visibility conditions in the 
affected Class I Federal area;
    (2) Emission limitations that reflect the degree of emission 
reduction achievable by such control measures and schedules for 
compliance as expeditiously as practicable; and
    (3) Monitoring, recordkeeping, and reporting requirements 
sufficient to ensure the enforceability of the emission limitations.
    (c) If a source that the Federal Land Manager has identified as 
responsible in whole or in part for reasonably attributable visibility 
impairment as part of a certification under paragraph (a) of this 
section is a BART-eligible source, and if there is not in effect as of 
the date of the certification a fully or conditionally approved 
implementation plan addressing the BART requirement for that source 
(which existing plan may incorporate either source-specific emission 
limitations reflecting the emission control performance of BART, an 
alternative program to address the BART requirement under Sec.  
51.308(e)(2) through (4), or for sources of SO2, a program 
approved under paragraph Sec.  51.309(d)(4)), then the State shall 
revise its regional haze implementation plan to meet the requirements 
of Sec.  51.308(e) with respect to that source, taking into account 
current conditions related to the factors listed in Sec.  
51.308(e)(1)(ii)(A). This requirement is in addition to the requirement 
of paragraph (b) of this section.
    (d) For any existing reasonably attributable visibility impairment 
the Federal Land Manager certifies to the State(s) under paragraph (a) 
of this section, the State(s) shall submit a revision to its regional 
haze implementation plan that includes the elements described in 
paragraphs (b) and (c) of this section no later than 3 years after the 
date of the certification. The State(s) is not required at that time to 
also revise its reasonable progress goals to reflect any additional 
emission reductions required from the source or sources. In no case 
shall such a revision in response to a reasonably attributable 
visibility impairment certification be due before July 31, 2021.

0
5. Section 51.303 is amended by revising paragraph (a)(1) to read as 
follows:


Sec.  51.303  Exemptions from control.

    (a)(1) Any existing stationary facility subject to the requirement 
under Sec.  51.302(c) or Sec.  51.308(e) to install, operate, and 
maintain BART may apply to the Administrator for an exemption from that 
requirement.
* * * * *

0
6. Revise Sec.  51.304 to read as follows:


Sec.  51.304  Identification of integral vistas.

    (a) Federal Land Managers were required to identify any integral 
vistas on or before December 31, 1985, according to criteria the 
Federal Land

[[Page 3124]]

Managers developed. These criteria must have included, but were not 
limited to, whether the integral vista was important to the visitor's 
visual experience of the mandatory Class I Federal area.
    (b) The following integral vistas were identified by Federal Land 
Managers: At Roosevelt Campobello International Park, from the 
observation point of Roosevelt cottage and beach area, the viewing 
angle from 244 to 256 degrees; and at Roosevelt Campobello 
International Park, from the observation point of Friar's Head, the 
viewing angle from 154 to 194 degrees.
    (c) The State must list in its implementation plan any integral 
vista listed in paragraph (b) of this section.

0
7. Revise Sec.  51.305 to read as follows:


Sec.  51.305  Monitoring for reasonably attributable visibility 
impairment.

    For the purposes of addressing reasonably attributable visibility 
impairment, if the Administrator, Regional Administrator, or the 
affected Federal Land Manager has advised a State containing a 
mandatory Class I Federal area of a need for monitoring to assess 
reasonably attributable visibility impairment at the mandatory Class I 
Federal area in addition to the monitoring currently being conducted to 
meet the requirements of Sec.  51.308(d)(4), the State must include in 
the next implementation plan revision to meet the requirement of Sec.  
51.308(f) an appropriate strategy for evaluating reasonably 
attributable visibility impairment in the mandatory Class I Federal 
area by visual observation or other appropriate monitoring techniques. 
Such strategy must take into account current and anticipated visibility 
monitoring research, the availability of appropriate monitoring 
techniques, and such guidance as is provided by the Agency.


Sec.  51.306  [Removed and Reserved]

0
8. Section 51.306 is removed and reserved.

0
9. Section 51.307 is amended by revising paragraphs (a) introductory 
text and (b)(1) and (2) to read as follows:


Sec.  51.307   New source review.

    (a) For purposes of new source review of any new major stationary 
source or major modification that would be constructed in an area that 
is designated attainment or unclassified under section 107(d) of the 
CAA, the State plan must, in any review under Sec.  51.166 with respect 
to visibility protection and analyses, provide for:
* * * * *
    (b) * * *
    (1) That may have an impact on any integral vista of a mandatory 
Class I Federal area listed in Sec.  51.304(b), or
    (2) That proposes to locate in an area classified as nonattainment 
under section 107(d)(1) of the Clean Air Act that may have an impact on 
visibility in any mandatory Class I Federal area.
* * * * *

0
10. Section 51.308 is amended by:
0
a. Revising paragraph (b);
0
b. Revising paragraphs (d)(2)(iv), (d)(3) introductory text, (e)(2)(v), 
(e)(4) and (5), (f), (g) introductory text, and (g)(3) through (7);
0
c. Adding paragraph (g)(8); and
0
d. Revising paragraphs (h) introductory text, (h)(1), (i)(2) 
introductory text, (i)(2)(ii), and (i)(3) and (4).
    The revisions and additions read as follows:


Sec.  51.308  Regional haze program requirements.

* * * * *
    (b) When are the first implementation plans due under the regional 
haze program? Except as provided in Sec.  51.309(c), each State 
identified in Sec.  51.300(b) must submit, for the entire State, an 
implementation plan for regional haze meeting the requirements of 
paragraphs (d) and (e) of this section no later than December 17, 2007.
* * * * *
    (d) * * *
    (2) * * *
    (iv) For the first implementation plan addressing the requirements 
of paragraphs (d) and (e) of this section, the number of deciviews by 
which baseline conditions exceed natural visibility conditions for the 
most impaired and least impaired days.
    (3) Long-term strategy for regional haze. Each State listed in 
Sec.  51.300(b) must submit a long-term strategy that addresses 
regional haze visibility impairment for each mandatory Class I Federal 
area within the State and for each mandatory Class I Federal area 
located outside the State that may be affected by emissions from the 
State. The long-term strategy must include enforceable emissions 
limitations, compliance schedules, and other measures as necessary to 
achieve the reasonable progress goals established by States having 
mandatory Class I Federal areas. In establishing its long-term strategy 
for regional haze, the State must meet the following requirements:
* * * * *
    (e) * * *
    (2) * * *
    (v) At the State's option, a provision that the emissions trading 
program or other alternative measure may include a geographic 
enhancement to the program to address the requirement under Sec.  
51.302(b) or (c) related to reasonably attributable impairment from the 
pollutants covered under the emissions trading program or other 
alternative measure.
* * * * *
    (4) A State whose sources are subject to a trading program 
established under part 97 of this chapter in accordance with a federal 
implementation plan set forth in Sec.  52.38 or Sec.  52.39 of this 
chapter or a trading program established under a SIP revision approved 
by the Administrator as meeting the requirements of Sec.  52.38 or 
Sec.  52.39 of this chapter need not require BART-eligible fossil fuel-
fired steam electric plants in the State to install, operate, and 
maintain BART for the pollutant covered by such trading program in the 
State. A State may adopt provisions, consistent with the requirements 
applicable to the State's sources for such trading program, for a 
geographic enhancement to the trading program to address any 
requirement under Sec.  51.302(b) or (c) related to reasonably 
attributable impairment from the pollutant covered by such trading 
program in that State.
    (5) After a State has met the requirements for BART or implemented 
an emissions trading program or other alternative measure that achieves 
more reasonable progress than the installation and operation of BART, 
BART-eligible sources will be subject to the requirements of paragraphs 
(d) and (f) of this section, as applicable, in the same manner as other 
sources.
* * * * *
    (f) Requirements for periodic comprehensive revisions of 
implementation plans for regional haze. Each State identified in Sec.  
51.300(b) must revise and submit its regional haze implementation plan 
revision to EPA by July 31, 2021, July 31, 2028, and every 10 years 
thereafter. The plan revision due on or before July 31, 2021, must 
include a commitment by the State to meet the requirements of paragraph 
(g) of this section. In each plan revision, the State 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. To meet 
the core requirements for regional haze for these areas, the State must 
submit an implementation plan containing the following plan elements 
and supporting documentation for all required analyses:

[[Page 3125]]

    (1) Calculations of baseline, current, and natural visibility 
conditions; progress to date; and the uniform rate of progress. For 
each mandatory Class I Federal area located within the State, the State 
must determine the following:
    (i) Baseline visibility conditions for the most impaired and 
clearest days. The period for establishing baseline visibility 
conditions is 2000 to 2004. The State must calculate the baseline 
visibility conditions for the most impaired days and the clearest days 
using available monitoring data. To determine the baseline visibility 
condition, the State must calculate the average of the annual deciview 
index values for the most impaired days and for the clearest days for 
the calendar years from 2000 to 2004. The baseline visibility condition 
for the most impaired days or the clearest days is the average of the 
respective annual values. For purposes of calculating the uniform rate 
of progress, the baseline visibility condition for the most impaired 
days must be associated with the last day of 2004. For mandatory Class 
I Federal areas without onsite monitoring data for 2000-2004, the State 
must establish baseline values using the most representative available 
monitoring data for 2000-2004, in consultation with the Administrator 
or his or her designee. For mandatory Class I Federal areas with 
incomplete monitoring data for 2000-2004, the State must establish 
baseline values using the 5 complete years of monitoring data closest 
in time to 2000-2004.
    (ii) Natural visibility conditions for the most impaired and 
clearest days. A State must calculate natural visibility condition by 
estimating the average deciview index existing under natural conditions 
for the most impaired days or the clearest days based on available 
monitoring information and appropriate data analysis techniques; and
    (iii) Current visibility conditions for the most impaired and 
clearest days. The period for calculating current visibility conditions 
is the most recent 5-year period for which data are available. The 
State must calculate the current visibility conditions for the most 
impaired days and the clearest days using available monitoring data. To 
calculate each current visibility condition, the State must calculate 
the average of the annual deciview index values for the years in the 
most recent 5-year period. The current visibility condition for the 
most impaired or the clearest days is the average of the respective 
annual values.
    (iv) Progress to date for the most impaired and clearest days. 
Actual progress made towards the natural visibility condition since the 
baseline period, and actual progress made during the previous 
implementation period up to and including the period for calculating 
current visibility conditions, for the most impaired and for the 
clearest days.
    (v) Differences between current visibility condition and natural 
visibility condition. The number of deciviews by which the current 
visibility condition exceeds the natural visibility condition, for the 
most impaired and for the clearest days.
    (vi) Uniform rate of progress. (A) The uniform rate of progress for 
each mandatory Class I Federal area in the State. To calculate the 
uniform rate of progress, the State must compare the baseline 
visibility condition for the most impaired days to the natural 
visibility condition for the most impaired days in the mandatory Class 
I Federal area and determine the uniform rate of visibility improvement 
(measured in deciviews of improvement per year) that would need to be 
maintained during each implementation period in order to attain natural 
visibility conditions by the end of 2064.
    (B) As part of its implementation plan submission, the State may 
propose (1) an adjustment to the uniform rate of progress for a 
mandatory Class I Federal area to account for impacts from 
anthropogenic sources outside the United States and/or (2) an 
adjustment to the uniform rate of progress for the mandatory Class I 
Federal area to account for impacts from wildland prescribed fires that 
were conducted with the objective to establish, restore, and/or 
maintain sustainable and resilient wildland ecosystems, to reduce the 
risk of catastrophic wildfires, and/or to preserve endangered or 
threatened species during which appropriate basic smoke management 
practices were applied. To calculate the proposed adjustment(s), the 
State must add the estimated impact(s) to the natural visibility 
condition and compare the baseline visibility condition for the most 
impaired days to the resulting sum. If the Administrator determines 
that the State has estimated the impact(s) from anthropogenic sources 
outside the United States and/or wildland prescribed fires using 
scientifically valid data and methods, the Administrator may approve 
the proposed adjustment(s) to the uniform rate of progress.
    (2) Long-term strategy for regional haze. Each State must submit a 
long-term strategy that addresses regional haze visibility impairment 
for each mandatory Class I Federal area within the State and for each 
mandatory Class I Federal area located outside the State that may be 
affected by emissions from the State. The long-term strategy must 
include the enforceable emissions limitations, compliance schedules, 
and other measures that are necessary to make reasonable progress, as 
determined pursuant to (f)(2)(i) through (iv). In establishing its 
long-term strategy for regional haze, the State must meet the following 
requirements:
    (i) The State must 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. The State should consider evaluating major 
and minor stationary sources or groups of sources, mobile sources, and 
area sources. The State must include in its implementation plan a 
description of the criteria it used to determine which sources or 
groups of sources it evaluated and how the four factors were taken into 
consideration in selecting the measures for inclusion in its long-term 
strategy. In considering the time necessary for compliance, if the 
State concludes that a control measure cannot reasonably be installed 
and become operational until after the end of the implementation 
period, the State may not consider this fact in determining whether the 
measure is necessary to make reasonable progress.
    (ii) The State must consult with those States that have emissions 
that are reasonably anticipated to contribute to visibility impairment 
in the mandatory Class I Federal area to develop coordinated emission 
management strategies containing the emission reductions necessary to 
make reasonable progress.
    (A) The State must demonstrate that it has included in its 
implementation plan all measures agreed to during state-to-state 
consultations or a regional planning process, or measures that will 
provide equivalent visibility improvement.
    (B) The State must consider the emission reduction measures 
identified by other States for their sources as being necessary to make 
reasonable progress in the mandatory Class I Federal area.
    (C) In any situation in which a State cannot agree with another 
State on the emission reduction measures necessary to make reasonable 
progress in a mandatory Class I Federal area, the State must describe 
the actions taken to resolve the disagreement. In reviewing the State's 
implementation plan, the

[[Page 3126]]

Administrator will take this information into account in determining 
whether the plan provides for reasonable progress at each mandatory 
Class I Federal area that is located in the State or that may be 
affected by emissions from the State. All substantive interstate 
consultations must be documented.
    (iii) The State must 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. The State may meet this requirement by 
relying on technical analyses developed by a regional planning process 
and approved by all State participants. The emissions information must 
include, but need not be limited to, information on emissions in a year 
at least as recent as the most recent year for which the State has 
submitted emission inventory information to the Administrator in 
compliance with the triennial reporting requirements of subpart A of 
this part. However, if a State has made a submission for a new 
inventory year to meet the requirements of subpart A in the period 12 
months prior to submission of the SIP, the State may use the inventory 
year of its prior submission.
    (iv) The State must consider the following additional factors in 
developing its long-term strategy:
    (A) Emission reductions due to ongoing air pollution control 
programs, including measures to address reasonably attributable 
visibility impairment;
    (B) Measures to mitigate the impacts of construction activities;
    (C) Source retirement and replacement schedules;
    (D) Basic smoke management practices for prescribed fire used for 
agricultural and wildland vegetation management purposes and smoke 
management programs; and
    (E) The anticipated net effect on visibility due to projected 
changes in point, area, and mobile source emissions over the period 
addressed by the long-term strategy.
    (3) Reasonable progress goals. (i) A state in which a mandatory 
Class I Federal area is located must establish reasonable progress 
goals (expressed in deciviews) that reflect the visibility conditions 
that are projected to be achieved by the end of the applicable 
implementation period as a result of those enforceable emissions 
limitations, compliance schedules, and other measures required under 
paragraph (f)(2) of this section that can be fully implemented by the 
end of the applicable implementation period, as well as the 
implementation of other requirements of the CAA. The long-term strategy 
and the reasonable progress goals must provide for an improvement in 
visibility for the most impaired days since the baseline period and 
ensure no degradation in visibility for the clearest days since the 
baseline period.
    (ii)(A) If a State in which a mandatory Class I Federal area is 
located establishes a reasonable progress goal for the most impaired 
days that provides for a slower rate of improvement in visibility than 
the uniform rate of progress calculated under paragraph (f)(1)(vi) of 
this section, the State must demonstrate, based on the analysis 
required by paragraph (f)(2)(i) of this section, that there are no 
additional emission reduction measures for anthropogenic sources or 
groups of sources in the State that may reasonably be anticipated to 
contribute to visibility impairment in the Class I area that would be 
reasonable to include in the long-term strategy. The State must provide 
a robust demonstration, including documenting the criteria used to 
determine which sources or groups or 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 State must provide to the public for review as part of 
its implementation plan an assessment of the number of years it would 
take to attain natural visibility conditions if visibility improvement 
were to continue at the rate of progress selected by the State as 
reasonable for the implementation period.
    (B) If a State contains sources which are reasonably anticipated to 
contribute to visibility impairment in a mandatory Class I Federal area 
in another State for which a demonstration by the other State is 
required under (f)(3)(ii)(A), the State must demonstrate that there are 
no additional emission reduction measures for anthropogenic sources or 
groups of sources in the State that may reasonably be anticipated to 
contribute to visibility impairment in the Class I area that would be 
reasonable to include in its own long-term strategy. The State must 
provide a robust demonstration, including documenting the criteria used 
to determine which sources or groups or 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.
    (iii) The reasonable progress goals established by the State are 
not directly enforceable but will be considered by the Administrator in 
evaluating the adequacy of the measures in the implementation plan in 
providing for reasonable progress towards achieving natural visibility 
conditions at that area.
    (iv) In determining whether the State's goal for visibility 
improvement provides for reasonable progress towards natural visibility 
conditions, the Administrator will also evaluate the demonstrations 
developed by the State pursuant to paragraphs (f)(2) and (f)(3)(ii)(A) 
of this section and the demonstrations provided by other States 
pursuant to paragraphs (f)(2) and (f)(3)(ii)(B) of this section.
    (4) If the Administrator, Regional Administrator, or the affected 
Federal Land Manager has advised a State of a need for additional 
monitoring to assess reasonably attributable visibility impairment at 
the mandatory Class I Federal area in addition to the monitoring 
currently being conducted, the State must include in the plan revision 
an appropriate strategy for evaluating reasonably attributable 
visibility impairment in the mandatory Class I Federal area by visual 
observation or other appropriate monitoring techniques.
    (5) So that the plan revision will serve also as a progress report, 
the State must address in the plan revision the requirements of 
paragraphs (g)(1) through (5) of this section. However, the period to 
be addressed for these elements shall be the period since the most 
recent progress report.
    (6) Monitoring strategy and other implementation plan requirements. 
The State must submit with the implementation plan a monitoring 
strategy for measuring, characterizing, and reporting of regional haze 
visibility impairment that is representative of all mandatory Class I 
Federal areas within the State. Compliance with this requirement may be 
met through participation in the Interagency Monitoring of Protected 
Visual Environments network. The implementation plan must also provide 
for the following:
    (i) The establishment of any additional monitoring sites or 
equipment needed to assess whether reasonable progress goals to address 
regional haze for all mandatory Class I Federal areas within the State 
are being achieved.
    (ii) 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.

[[Page 3127]]

    (iii) For a State with no mandatory Class I Federal areas, 
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.
    (iv) The implementation plan must provide for the reporting of all 
visibility monitoring data to the Administrator at least annually for 
each mandatory Class I Federal area in the State. To the extent 
possible, the State should report visibility monitoring data 
electronically.
    (v) A statewide inventory of emissions of pollutants that are 
reasonably anticipated to cause or contribute to visibility impairment 
in any mandatory Class I Federal area. The inventory must include 
emissions for the most recent year for which data are available, and 
estimates of future projected emissions. The State must also include a 
commitment to update the inventory periodically.
    (vi) Other elements, including reporting, recordkeeping, and other 
measures, necessary to assess and report on visibility.
    (g) Requirements for periodic reports describing progress towards 
the reasonable progress goals. Each State identified in Sec.  51.300(b) 
must periodically submit a report to the Administrator evaluating 
progress towards the reasonable progress goal for 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. The first progress report is due 5 
years from submittal of the initial implementation plan addressing 
paragraphs (d) and (e) of this section. The first progress reports must 
be in the form of implementation plan revisions that comply with the 
procedural requirements of Sec.  51.102 and Sec.  51.103. Subsequent 
progress reports are due by January 31, 2025, July 31, 2033, and every 
10 years thereafter. Subsequent progress reports must be made available 
for public inspection and comment for at least 30 days prior to 
submission to EPA and all comments received from the public must be 
submitted to EPA along with the subsequent progress report, along with 
an explanation of any changes to the progress report made in response 
to these comments. Periodic progress reports must contain at a minimum 
the following elements:
* * * * *
    (3) For each mandatory Class I Federal area within the State, the 
State must assess the following visibility conditions and changes, with 
values for most impaired, least impaired and/or clearest days as 
applicable expressed in terms of 5-year averages of these annual 
values. The period for calculating current visibility conditions is the 
most recent 5-year period preceding the required date of the progress 
report for which data are available as of a date 6 months preceding the 
required date of the progress report.
    (i)(A) Progress reports due before January 31, 2025. The current 
visibility conditions for the most impaired and least impaired days.
    (B) Progress reports due on and after January 31, 2025. The current 
visibility conditions for the most impaired and clearest days;
    (ii)(A) Progress reports due before January 31, 2025. The 
difference between current visibility conditions for the most impaired 
and least impaired days and baseline visibility conditions.
    (B) Progress reports due on and after January 31, 2025. The 
difference between current visibility conditions for the most impaired 
and clearest days and baseline visibility conditions.
    (iii)(A) Progress reports due before January 31, 2025. The change 
in visibility impairment for the most impaired and least impaired days 
over the period since the period addressed in the most recent plan 
required under paragraph (f) of this section.
    (B) Progress reports due on and after January 31, 2025. The change 
in visibility impairment for the most impaired and clearest days over 
the period since the period addressed in the most recent plan required 
under paragraph (f) of this section.
    (4) An analysis tracking the change over the period since the 
period addressed in the most recent plan required under paragraph (f) 
of this section in emissions of pollutants contributing to visibility 
impairment from all sources and activities within the State. Emissions 
changes should be identified by type of source or activity. With 
respect to all sources and activities, the analysis must extend at 
least through the most recent year for which the state has submitted 
emission inventory information to the Administrator in compliance with 
the triennial reporting requirements of subpart A of this part as of a 
date 6 months preceding the required date of the progress report. With 
respect to sources that report directly to a centralized emissions data 
system operated by the Administrator, the analysis must extend through 
the most recent year for which the Administrator has provided a State-
level summary of such reported data or an internet-based tool by which 
the State may obtain such a summary as of a date 6 months preceding the 
required date of the progress report. The State is not required to 
backcast previously reported emissions to be consistent with more 
recent emissions estimation procedures, and may draw attention to 
actual or possible inconsistencies created by changes in estimation 
procedures.
    (5) An assessment of any significant changes in anthropogenic 
emissions within or outside the State that have occurred since the 
period addressed in the most recent plan required under paragraph (f) 
of this section including whether or not these changes in anthropogenic 
emissions were anticipated in that most recent plan and whether they 
have limited or impeded progress in reducing pollutant emissions and 
improving visibility.
    (6) An assessment of whether the current implementation plan 
elements and strategies are sufficient to enable the State, or other 
States with mandatory Class I Federal areas affected by emissions from 
the State, to meet all established reasonable progress goals for the 
period covered by the most recent plan required under paragraph (f) of 
this section.
    (7) For progress reports for the first implementation period only, 
a review of the State's visibility monitoring strategy and any 
modifications to the strategy as necessary.
    (8) For a state with a long-term strategy that includes a smoke 
management program for prescribed fires on wildland that conducts a 
periodic program assessment, a summary of the most recent periodic 
assessment of the smoke management program including conclusions if any 
that were reached in the assessment as to whether the program is 
meeting its goals regarding improving ecosystem health and reducing the 
damaging effects of catastrophic wildfires.
    (h) Determination of the adequacy of existing implementation plan. 
At the same time the State is required to submit any progress report to 
EPA in accordance with paragraph (g) of this section, the State must 
also take one of the following actions based upon the information 
presented in the progress report:
    (1) If the State determines that the existing implementation plan 
requires no further substantive revision at this time in order to 
achieve established goals for visibility improvement and emissions 
reductions, the State must provide to the Administrator a declaration 
that revision of the existing

[[Page 3128]]

implementation plan is not needed at this time.
* * * * *
    (i) * * *
    (2) The State must provide the Federal Land Manager with an 
opportunity for consultation, in person at a point early enough in the 
State's policy analyses of its long-term strategy emission reduction 
obligation so that information and recommendations provided by the 
Federal Land Manager can meaningfully inform the State's decisions on 
the long-term strategy. The opportunity for consultation will be deemed 
to have been early enough if the consultation has taken place at least 
120 days prior to holding any public hearing or other public comment 
opportunity on an implementation plan (or plan revision) for regional 
haze required by this subpart. The opportunity for consultation on an 
implementation plan (or plan revision) or on a progress report must be 
provided no less than 60 days prior to said public hearing or public 
comment opportunity. This consultation must include the opportunity for 
the affected Federal Land Managers to discuss their:
* * * * *
    (ii) Recommendations on the development and implementation of 
strategies to address visibility impairment.
    (3) In developing any implementation plan (or plan revision) or 
progress report, the State must include a description of how it 
addressed any comments provided by the Federal Land Managers.
    (4) The plan (or plan revision) must provide procedures for 
continuing consultation between the State and Federal Land Manager on 
the implementation of the visibility protection program required by 
this subpart, including development and review of implementation plan 
revisions and progress reports, and on the implementation of other 
programs having the potential to contribute to impairment of visibility 
in mandatory Class I Federal areas.

0
11. Section 51.309 is amended by:
0
a. Revising paragraph (b)(4);
0
b. Removing and reserving paragraph (b)(8);
0
c. Revising paragraphs (d)(4)(v), (d)(10) introductory text, (d)(10)(i) 
introductory text, and (d)(10)(ii) introductory text;
0
d. Adding paragraphs (d)(10)(iii) and (iv); and
0
e. Revising paragraph (g)(2)(iii).
    The revisions and additions read as follows:


Sec.  51.309  Requirements related to the Grand Canyon Visibility 
Transport Commission.

* * * * *
    (b) * * *
    (4) Fire means wildfire, wildland fire, prescribed fire, and 
agricultural burning conducted and occurring on Federal, State, and 
private wildlands and farmlands.
* * * * *
    (d) * * *
    (4) * * *
    (v) Market trading program. The implementation plan must include 
requirements for a market trading program to be implemented in the 
event that a milestone is not achieved. The plan shall require that the 
market trading program be activated beginning no later than 15 months 
after the end of the first year in which the milestone is not achieved. 
The plan shall also require that sources comply, as soon as 
practicable, with the requirement to hold allowances covering their 
emissions. Such market trading program must be sufficient to achieve 
the milestones in paragraph (d)(4)(i) of this section, and must be 
consistent with the elements for such programs outlined in Sec.  
51.308(e)(2)(vi). Such a program may include a geographic enhancement 
to the program to address the requirement under Sec.  51.302(b) related 
to reasonably attributable impairment from the pollutants covered under 
the program.
* * * * *
    (10) Periodic implementation plan revisions and progress reports. 
Each Transport Region State must submit to the Administrator periodic 
reports in the years 2013 and as specified for subsequent progress 
reports in Sec.  51.308(g). The progress report due in 2013 must be in 
the form of an implementation plan revision that complies with the 
procedural requirements of Sec. Sec.  51.102 and 51.103.
    (i) The report due in 2013 will assess the area for reasonable 
progress as provided in this section for mandatory Class I Federal 
area(s) located within the State and for mandatory Class I Federal 
area(s) located outside the State that may be affected by emissions 
from within the State. This demonstration may be based on assessments 
conducted by the States and/or a regional planning body. The progress 
report due in 2013 must contain at a minimum the following elements:
* * * * *
    (ii) At the same time the State is required to submit the 5-year 
progress report due in 2013 to EPA in accordance with paragraph 
(d)(10)(i) of this section, the State must also take one of the 
following actions based upon the information presented in the progress 
report:
* * * * *
    (iii) The requirements of Sec.  51.308(g) regarding requirements 
for periodic reports describing progress towards the reasonable 
progress goals apply to States submitting plans under this section, 
with respect to subsequent progress reports due after 2013.
    (iv) The requirements of Sec.  51.308(h) regarding determinations 
of the adequacy of existing implementation plans apply to States 
submitting plans under this section, with respect to subsequent 
progress reports due after 2013.
* * * * *
    (g) * * *
    (2) * * *
    (iii) The Transport Region State may consider whether any 
strategies necessary to achieve the reasonable progress goals required 
by paragraph (g)(2) of this section are incompatible with the 
strategies implemented under paragraph (d) of this section to the 
extent the State adequately demonstrates that the incompatibility is 
related to the costs of the compliance, the time necessary for 
compliance, the energy and nonair quality environmental impacts of 
compliance, or the remaining useful life of any existing source subject 
to such requirements.

PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

0
12. The authority citation for part 52 continues to read as follows:

    Authority: 42 U.S.C. 7401 et seq.


Sec.  52.26  [Removed and Reserved]

0
13. Section 52.26 is removed and reserved.


Sec.  52.29   [Removed and Reserved]

0
14. Section 52.29 is removed and reserved.


Sec.  52.61   [Amended]

0
15. Section 52.61 is amended by removing and reserving paragraph (b).

0
16. Section 52.145 is amended by revising paragraph (b) and removing 
and reserving paragraph (c).
    The revision reads as follows:


Sec.  52.145   Visibility protection.

* * * * *
    (b) Regulations for visibility monitoring and new source review. 
The provisions of Sec. Sec.  52.27 and 52.28 are hereby incorporated 
and made part of

[[Page 3129]]

the applicable plan for the State of Arizona.
* * * * *


Sec.  52.281  [Amended]

0
17. Section 52.281 is amended by removing and reserving paragraphs (b) 
and (e).

0
18. Section 52.344 is amended by revising paragraph (b) to read as 
follows:


Sec.  52.344  Visibility protection.

* * * * *
    (b) The Visibility NSR regulations are approved for industrial 
source categories regulated by the NSR and PSD regulations which have 
previously been approved by EPA. However, Colorado's NSR and PSD 
regulations have been disapproved for certain sources as listed in 40 
CFR 52.343(a)(1). The provisions of 40 CFR 52.28 are hereby 
incorporated and made a part of the applicable plan for the State of 
Colorado for these sources.

0
19. Section 52.633 is amended by revising paragraph (b) and removing 
and reserving paragraph (c).
    The revision reads as follows.


Sec.  52.633  Visibility protection.

* * * * *
    (b) Regulations for visibility monitoring and new source review. 
The provisions of Sec. Sec.  52.27 and 52.28 are hereby incorporated 
and made part of the applicable plan for the State of Hawaii.
* * * * *


Sec.  52.690   [Amended]

0
20. Section 52.690 is amended by removing and reserving paragraphs (b) 
and (c).


Sec.  52.1033   [Amended]

0
21. Section 52.1033 is amended by removing and reserving paragraphs (a) 
and (c).

0
22. Section 52.1183 is amended by revising paragraph (b) and removing 
and reserving paragraphs (a) and (c).
    The revision reads as follows.


Sec.  52.1183   Visibility protection.

* * * * *
    (b) Regulation for visibility monitoring and new source review. The 
provisions of Sec.  52.28 are hereby incorporated and made a part of 
the applicable plan for the State of Michigan.
* * * * *

0
23. Section 52.1236 is amended by revising paragraph (b) and removing 
and reserving paragraph (c).
    The revision reads as follows:


Sec.  52.1236   Visibility protection.

* * * * *
    (b) Regulation for visibility monitoring and new source review. The 
provisions of Sec.  52.28 are hereby incorporated and made a part of 
the applicable plan for the State of Minnesota.
* * * * *


Sec.  52.1339   [Amended]

0
24. Section 52.1339 is amended by removing and reserving paragraph (b).


Sec.  52.1387   [Amended]

0
25. Section 52.1387 is amended by removing and reserving paragraph (b).

0
26. Section 52.1488 is amended by revising paragraph (b) and removing 
and reserving paragraph (c).
    The revision reads as follows.


Sec.  52.1488  Visibility protection.

* * * * *
    (b) Regulation for visibility monitoring and new source review. The 
provisions of Sec.  52.28 are hereby incorporated and made a part of 
the applicable plan for the State of Nevada except for that portion 
applicable to the Clark County Department of Air Quality and 
Environmental Management.
* * * * *

0
27. Section 52.1531 is amended by revising paragraph (b) and removing 
and reserving paragraph (c).
    The revision reads as follows.


Sec.  52.1531  Visibility protection.

* * * * *
    (b) Regulation for visibility monitoring and new source review. The 
provisions of Sec.  52.28 are hereby incorporated and made a part of 
the applicable plan for the State of New Hampshire.
* * * * *


Sec.  52.2132   [Amended]

0
28. Section 52.2132 is amended by removing and reserving paragraphs (b) 
and (c).

0
29. Section 52.2179 is amended by revising paragraph (b) and removing 
and reserving paragraph (c).
    The revision reads as follows:


Sec.  52.2179  Visibility protection.

* * * * *
    (b) Regulation for visibility monitoring and new source review. The 
provisions of Sec.  52.28 are hereby incorporated and made a part of 
the applicable plan for the State of South Dakota.
* * * * *


Sec.  52.2304   [Amended]

0
30. Section 52.2304 is amended by removing and reserving paragraph (b).

0
31. Section 52.2383 is amended by revising paragraph (b) to read as 
follows:


Sec.  52.2383  Visibility protection.

* * * * *
    (b) Regulations for visibility monitoring and new source review. 
The provisions of Sec.  52.27 are hereby incorporated and made part of 
the applicable plan for the State of Vermont.

0
32. Section 52.2452 is amended by revising paragraph (a) and removing 
and reserving paragraphs (b) and (c).
    The revision reads as follows:


Sec.  52.2452  Visibility protection.

    (a) Reasonably Attributable Visibility Impairment. The requirements 
of section 169A of the Clean Air Act are not met because the plan does 
not include approvable measures for meeting the requirements of 40 CFR 
51.305 for protection of visibility in mandatory Class I Federal areas.
* * * * *

0
33. Section 52.2533 is amended by revising paragraphs (a) and (b) and 
removing and reserving paragraph (c).
    The revision reads as follows:


Sec.  52.2533  Visibility protection.

    (a) Reasonably Attributable Visibility Impairment. The requirements 
of section 169A of the Clean Air Act are not met because the plan does 
not include approvable measures for meeting the requirements of 40 CFR 
51.305 and 51.307 for protection of visibility in mandatory Class I 
Federal areas.
    (b) Regulation for visibility monitoring and new source review. The 
provisions of Sec.  52.28 are hereby incorporated and made a part of 
the applicable plan for the State of West Virginia.
* * * * *


Sec.  52.2781  [Amended]

0
34. Section 52.2781 is amended by removing and reserving paragraphs (b) 
and (c).

[FR Doc. 2017-00268 Filed 1-9-17; 8:45 am]
BILLING CODE 6560-50-P


