Document ID: EPA-HQ-OAR-2016-0202-0001
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: 2015 National Ambient Air Quality Standards for Ozone
Posted Date: 2016-11-17T05:00Z

[Federal Register Volume 81, Number 222 (Thursday, November 17, 2016)]
[Proposed Rules]
[Pages 81276-81317]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-27333]

[[Page 81275]]

Vol. 81

Thursday,

No. 222

November 17, 2016

Part III

Environmental Protection Agency

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40 CFR Parts 50 and 51

Implementation of the 2015 National Ambient Air Quality Standards for 
Ozone: Nonattainment Area Classifications and State Implementation Plan 
Requirements; Proposed Rule

  Federal Register / Vol. 81 , No. 222 / Thursday, November 17, 2016 / 
Proposed Rules  

[[Page 81276]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 50 and 51

[EPA-HQ-OAR-2016-0202; FRL-9950-24-OAR]
RIN 2060-AS82

Implementation of the 2015 National Ambient Air Quality Standards 
for Ozone: Nonattainment Area Classifications and State Implementation 
Plan Requirements

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing 
nonattainment area classification thresholds and implementation 
requirements for the strengthened 2015 ozone national ambient air 
quality standards (NAAQS) (2015 ozone NAAQS) that were promulgated on 
October 1, 2015. This proposal is largely an update to the implementing 
regulations previously promulgated for the 2008 ozone NAAQS, and we 
propose to retain without significant revision the majority of those 
provisions to implement the 2015 ozone NAAQS. This proposal addresses 
the timing of attainment dates for each nonattainment area 
classification and a range of nonattainment area state implementation 
plan (SIP) requirements for the 2015 ozone NAAQS. The proposed SIP 
requirements pertain to attainment demonstrations, reasonable further 
progress (RFP) and associated milestone demonstrations, reasonably 
available control technology (RACT), reasonably available control 
measures (RACM), major nonattainment new source review (NNSR), emission 
inventories, the timing of required SIP submissions, and compliance 
with emission control measures in the SIP. Other issues addressed in 
this proposed rule are the revocation of the 2008 ozone NAAQS, anti-
backsliding requirements that would apply when the 2008 ozone NAAQS are 
revoked, and reconsideration of the ozone NAAQS interprecursor trading 
(IPT) provisions (in response to a petition for reconsideration).

DATES: Comments. Written comments must be received on or before January 
17, 2017. Public Hearing. If anyone contacts us requesting a hearing on 
or before December 2, 2016, we will hold a hearing. Additional 
information about the hearing, if requested, will be published in a 
subsequent Federal Register document. Information Collection Request. 
Under the Paperwork Reduction Act (PRA), comments on the information 
collection provisions are best assured of having full effect if the 
Office of Management and Budget (OMB) receives a copy of your comments 
on or before December 19, 2016.

ADDRESSES: Comments: Submit your comments, identified by Docket ID No. 
EPA-HQ-OAR-2016-0202, at http://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. The EPA may publish any 
comment received to its public docket. Do not submit electronically any 
information you consider to be Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. The EPA 
will generally not consider comments or comment contents located 
outside of the primary submission (i.e., on the Web, Cloud or other 
file sharing system). For additional submission methods, the full EPA 
public comment policy, information about CBI or multimedia submissions 
and general guidance on making effective comments, please visit http://www2.epa.gov/dockets/comments.html.

FOR FURTHER INFORMATION CONTACT: For further general information on 
this proposed rule, contact Mr. Robert Lingard, Office of Air Quality 
Planning and Standards (OAQPS), U.S. EPA, at (919) 541-5272 or 
lingard.robert@epa.gov; or Mr. Lynn Dail, OAQPS, U.S. EPA, at (919) 
541-2363 or dail.lynn@epa.gov. For information on the Information 
Collection Request (ICR), contact Mr. Butch Stackhouse, OAQPS, U.S. 
EPA, at (919) 541-5208 or stackhouse.butch@epa.gov. For information on 
the public hearing, contact Ms. Pamela Long, OAQPS, U.S. EPA, at (919) 
541-0641 or long.pam@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Preamble Glossary of Terms and Acronyms

    The following are abbreviations of terms used in the preamble.

ACT Alternative Control Techniques
AERR Air Emissions Reporting Requirements
AVERT AVoided Emissions geneRation Tool
BSMP Basic Smoke Management Practices
CAA Clean Air Act
CAIR Clean Air Interstate Rule
CBI Confidential Business Information
CFR Code of Federal Regulations
CO Carbon Monoxide
CSAPR Cross-State Air Pollution Rule
CTG Control Techniques Guidelines
DOI Department of the Interior
DOT Department of Transportation
DV Design Value
EE/RE Energy Efficiency and Renewable Energy
EPA Environmental Protection Agency
FIP Federal Implementation Plan
FLM Federal Land Managers
FR Federal Register
ICR Information Collection Request
I/M Inspection and Maintenance
IPT Interprecursor Trade or Interprecursor Trading
MCD Milestone Compliance Demonstration
MPO Metropolitan Planning Organization
NAAQS National Ambient Air Quality Standards
NNSR Nonattainment New Source Review
NOX Nitrogen Oxides
O3 Ozone
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
OTR Ozone Transport Region
PAMS Photochemical Assessment Monitoring Station
PM2.5 Fine Particulate Matter
ppm Parts per Million
PRA Paperwork Reduction Act
PSD Prevention of Significant Deterioration
PTE Potential to Emit
PUC Public Utility Commission
RACM Reasonably Available Control Measures
RACT Reasonably Available Control Technology
RFP Reasonable Further Progress
ROP Rate of Progress
RPS Renewable Portfolio Standard
SIP State Implementation Plan
SO2 Sulfur Dioxide
tpy Tons per Year
TAR Tribal Authority Rule
TAS Treatment as a State
TGD Technical Guidance Document
TIP Tribal Implementation Plan
TIP Transportation Improvement Program
TSD Technical Support Document
USB U.S. Background
U.S.C. United States Code
USDA U.S. Department of Agriculture
VOC Volatile Organic Compounds

B. Does this action apply to me?

    Entities potentially affected directly by this proposed rule 
include state, local and tribal governments and air pollution control 
agencies (``air agencies'') responsible for attainment and maintenance 
of the NAAQS. Entities potentially affected indirectly by this proposed 
rule as regulated sources include owners and operators of sources of 
emissions of volatile organic compounds (VOCs) and nitrogen oxides

[[Page 81277]]

(NOX) that contribute to ground-level ozone formation.

C. What should I consider as I prepare my comments for the EPA?

    When submitting comments, remember to:
     Identify the rulemaking docket by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Follow directions. The proposed rule may ask you to 
respond to specific questions or organize comments by referencing a 
Code of Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree, suggest alternatives 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used to support your comment.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns 
wherever possible, and suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.
     Make sure to submit your comments by the comment period 
deadline identified.

D. How can I find information about a possible hearing?

    To request a public hearing or information pertaining to a public 
hearing regarding this document, contact Ms. Pamela Long, OAQPS, U.S. 
EPA, at (919) 541-0641 or long.pam@epa.gov.

E. Where can I get 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/ozone-pollution.

F. How is this notice of proposed rulemaking organized?

    The information and proposals presented in this notice are 
organized as follows:

I. General Information
    A. Preamble Glossary of Terms and Acronyms
    B. Does this action apply to me?
    C. What should I consider as I prepare my comments for the EPA?
    D. How can I find information about a possible hearing?
    E. Where can I get a copy of this document and other related 
information?
    F. How is this notice of proposed rulemaking organized?
II. Summary of Proposed Rule and Background
III. Provisions of the 2008 Ozone NAAQS Implementing Regulations To 
Be Retained Without Significant Revision
    A. Submitting Nonattainment Area and OTR SIP Elements Due Under 
CAA Sections 182 and 184 for the 2015 Ozone NAAQS
    B. Applicability of Existing NAAQS Implementation Provisions in 
40 CFR Part 51
    C. General Classification and Nonattainment Area Planning 
Provisions
    D. Redesignation to Nonattainment Following Initial Designations
    E. Determining Eligibility for 1-Year Attainment Date Extensions 
for the 2015 Ozone NAAQS Under CAA Section 181(a)(5)
    F. Modeling and Attainment Demonstration Requirements
    G. Requirements for RFP
    H. Requirements for RACT and RACM
    I. CAA Section 182(f) NOX Exemption Provisions
    J. General Nonattainment NSR Requirements
    K. Ambient Monitoring Requirements
    L. Requirements for an OTR
    M. Fee Programs for Severe and Extreme Nonattainment Areas That 
Fail To Attain
    N. Applicability
IV. Provisions of the 2008 Ozone NAAQS Implementing Regulations To 
Be Retained With Specific Revisions
    A. Application of Classification and Attainment Date Provisions 
in CAA Section 181 to Areas Subject to Subpart 2 of Part D of Title 
I of the CAA
    B. Transition From the 2008 Ozone NAAQS to the 2015 Ozone NAAQS 
and Anti-Backsliding Requirements
    C. Requirements for RFP: Milestone Compliance Demonstrations 
(MCD)
    D. Requirements for RACT: Deadlines for Submittal and 
Implementation of RACT SIP Revisions
    E. Requirements for RACM: Consideration of Sources of Intrastate 
Transport of Pollution
    F. Nonattainment NSR Offset Requirement: Interprecursor Trading 
for Ozone Offsets
    G. Emissions Inventory and Emissions Statement Requirements
V. Additional Considerations
    A. Managing Emissions From Wildfire and Wildland Prescribed Fire
    B. Transportation Conformity and General Conformity
    C. Requirements for Contingency Measures in the Event of Failure 
To Meet a Milestone or To Attain
    D. International Transport and Background Ozone
    E. Additional Policies and Programs for Achieving Emissions 
Reductions
    F. Additional Requirements Related to Enforcement and Compliance
    G. Applicability of Proposed Rule to Tribes
VI. Environmental Justice Considerations
VII. 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 (NTTA)
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
VIII. Statutory Authority

II. Summary of Proposed Rule and Background

    On October 1, 2015,\1\ the EPA announced that it was strengthening 
the primary and secondary NAAQS for ozone to a level of 0.070 parts per 
million (ppm).\2\ Since the 2015 primary and secondary NAAQS for ozone 
are identical, for convenience, we refer to both as ``the 2015 ozone 
NAAQS'' or ``the 2015 ozone standards.'' The 2015 ozone NAAQS retains 
the same general form and averaging time as the 0.075 ppm NAAQS set in 
2008, but is set at a more protective level.
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    \1\ See 80 FR 65292.
    \2\ Annual fourth highest daily maximum 8-hour average 
concentration, averaged over 3 years. For a detailed explanation of 
the calculation of the 3-year 8-hour average, see 40 CFR part 50, 
Appendix P.
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    The revisions to the ozone NAAQS trigger a process under which 
states recommend area designations (i.e., as nonattainment, attainment, 
or unclassifiable) to the EPA. The EPA then evaluates air quality data 
and other factors prior to making its proposed and final determinations 
regarding area designations. To aid the states developing their 
recommendations, the EPA issued area designations guidance on February 
25, 2016.\3\ Areas designated as nonattainment for the revised ozone 
NAAQS will be classified at the time of designation. With this action, 
the EPA is proposing and seeking comment on air quality thresholds and 
attainment dates for each nonattainment area classification, which it 
will finalize upon or before promulgating final area

[[Page 81278]]

designations and classifications for the 2015 ozone NAAQS.
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    \3\ The EPA's guidance on the area designations for the 2015 
ozone NAAQS is available at https://www.epa.gov/ozone-designations/epa-guidance-area-designations-2015-ozone-naaqs.
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    The Clean Air Act (CAA or Act) does not require that the EPA 
promulgate new or revised implementing regulations or guidance every 
time that a NAAQS is revised. State, local and tribal air agencies 
(hereinafter, referred to simply as air agencies) are required to 
submit SIPs as provided in the CAA and in EPA regulations. Where the 
nature of revisions to a NAAQS indicate that additional regulations or 
guidance (or revisions to existing regulations or guidance) may be 
helpful, the EPA endeavors to provide such regulations or guidance to 
facilitate the designations process and preparation of timely SIP 
submittals. It is important to note, however, that the existing EPA 
regulations in 40 CFR part 51 applicable to SIPs generally and to 
particular pollutants (e.g., ozone and its precursors) continue to 
apply even without such updates. This rule is proposing revisions to 
existing regulations and guidance as appropriate to aid in the 
implementation of the 2015 ozone NAAQS.
    The EPA believes that the overall framework and policy approach of 
the implementation provisions associated with the 2008 ozone NAAQS 
provide an effective and appropriate template for the general approach 
air agencies should follow in planning for attainment of the revised 
ozone standards. However, to assist with the implementation of the 
revised ozone standards, the EPA is proposing this additional ozone 
NAAQS implementation rule.
    We are proposing multiple actions in this rule pertaining to 
nonattainment area classification thresholds and associated attainment 
dates, as well as submittal deadlines and specific CAA requirements for 
the content of nonattainment area and Ozone Transport Region (OTR) SIPs 
for the 2015 ozone NAAQS. As a general matter, this proposed rule 
follows the same basic principles and approach that the EPA applied to 
interpret the CAA's part D, subpart 2 ozone nonattainment area 
requirements in developing the classification and implementation rules 
for the 2008 ozone NAAQS.\4\ Additionally, we are proposing and seeking 
comment on two alternative approaches for revoking the 2008 ozone NAAQS 
and, where applicable, establishing anti-backsliding requirements for 
areas that are designated nonattainment at the time the 2008 ozone 
NAAQS is revoked.
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    \4\ See the Classifications Rule (77 FR 30160; May 21, 2012) and 
SIP Requirements Rule (80 FR 12264; March 6, 2015) for the 2008 
ozone NAAQS.
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    Regarding the format of this preamble, we organize our discussion 
of implementation requirements for the 2015 ozone NAAQS around the 
implementing regulations for the 2008 ozone NAAQS. As stated 
previously, we propose to retain without significant revision the 
majority of those existing regulations to implement the 2015 ozone 
NAAQS, as discussed in Section III of this preamble. We discuss the 
existing implementing regulations that we propose to retain with 
specific revisions for implementing the 2015 ozone NAAQS in Section IV 
of this preamble. For topics where we do not propose any action, we 
provide guidance on that topic in the preamble. Section V of this 
preamble addresses several requirements and policies not covered by 
this proposed rulemaking (with one exception), but for which the EPA is 
soliciting public comment (e.g., dealing with emissions from wildfires 
and wildland prescribed fires, and international transport and 
background ozone).

III. Provisions of the 2008 Ozone NAAQS Implementing Regulations To Be 
Retained Without Significant Revision

    For purposes of the 2015 ozone NAAQS, we are proposing to retain 
the majority of existing implementation provisions for the 2008 ozone 
NAAQS without significant revision. The existing classification and SIP 
requirement provisions for the 2008 standards are codified at subpart 
AA of 40 CFR part 51, and the corresponding provisions for the 2015 
standards would be codified at the new subpart CC of part 51. As 
discussed earlier, the EPA believes that the implementing regulations 
for the 2008 standards generally provide an appropriate approach to 
follow in attainment planning for the 2015 standards, and we welcome 
comment on the following proposed provisions.

A. Submitting Nonattainment Area and OTR SIP Elements Due Under CAA 
Sections 182 and 184 for the 2015 Ozone NAAQS

1. Deadlines for Submitting Nonattainment Area and OTR SIP Elements
    The EPA is proposing to retain the existing approach to calculating 
deadlines for submitting nonattainment SIP elements. Section 182 of the 
CAA requires states with ozone nonattainment areas to submit various 
SIP elements within specified time periods after enactment of the CAA 
Amendments of 1990. For the 2008 ozone NAAQS, the EPA adopted the 
approach that the SIP elements listed in the proposal are due based on 
the timeframes provided in CAA section 182 as measured from the 
effective date of designation, instead of the 1990 date. For reference, 
the final 2008 Ozone NAAQS SIP Requirements Rule (2008 ozone SRR) 
provides an extensive discussion of the EPA's current approach and 
rationale for SIP element submittal deadlines (80 FR 12265; March 6, 
2015). The EPA is proposing to retain the same approach for calculating 
deadlines for submitting nonattainment area SIP elements under CAA 
section 182 for the 2015 ozone NAAQS, based on the current approach and 
rationale articulated in the final 2008 Ozone NAAQS SIP Requirements 
Rule.
    Accordingly, states with areas designated nonattainment have 2 
years from the effective date of nonattainment designation to submit 
SIP revisions addressing emission inventories (required by CAA section 
182(a)(1)), RACT (CAA section 182(b)(2)) and emissions statement 
regulations \5\ (CAA section 182(a)(3)(B)); 3 years to submit SIP 
revisions addressing 15 percent rate of progress (ROP) plans (CAA 
section 182(b)(1)) and Moderate area attainment demonstrations (CAA 
section 182(b)(1)); and 4 years to submit SIP revisions addressing 3 
percent per year \6\ RFP plans (CAA section 182(c)(2)) and attainment 
demonstrations (CAA section 182(c)(2)) for Serious and higher areas, 
where applicable. If an area is subject to vehicle inspection and 
maintenance (I/M) program requirements based on its classification, the 
SIP revision due date, codified in 40 CFR 51.372(b)(2), would be 
aligned with the due date for the attainment demonstration SIP for the 
area. The SIP revisions addressing CAA section 185 penalty fee programs 
in areas initially classified Severe or Extreme would be due 10 years 
from the effective date of designations. Finally, SIP submissions 
addressing nonattainment NSR would be due 3 years \7\ from the 
effective date of designations.
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    \5\ See Section IV.G of this preamble for additional information 
on emissions statements.
    \6\ 3 percent per year RFP plans are typically submitted in 3-
year increments, thus, as 9 percent RFP plans that produce average 
reductions of 3 percent per year.
    \7\ See 70 FR 71612, 71672 and 71683 (November 29, 2005); and 80 
FR 12264, 12266 and 12267, March 6, 2015.
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    We note also that the EPA's implementing regulations for revised 
ozone NAAQS have required OTR states

[[Page 81279]]

to submit RACT SIP revisions based on the timeframe provided in CAA 
section 184 as measured from the effective date for designations made 
pursuant to those revised NAAQS. This requirement was first codified in 
40 CFR 51.916 for the 1997 ozone NAAQS, and later codified for the 2008 
ozone NAAQS in 40 CFR 51.1116. Under those provisions, states in the 
OTR are required to submit SIP revisions addressing the RACT 
requirements of CAA section 184 no later than 2 years after the 
effective date of designations for the revised ozone NAAQS. The EPA is 
proposing to retain these same general requirements for the 2015 ozone 
NAAQS (see Section III.L of this preamble).
2. Form and Content of Nonattainment and OTR SIP Element Submissions 
Required Under a Revised NAAQS
    The EPA is restating the existing requirement that states must 
submit all nonattainment SIP elements applicable for an area's 
classification upon revision of the NAAQS, and is providing the 
following guidance on the form and content of such submissions. As 
discussed in the preceding section, a SIP submission is due from air 
agencies for every nonattainment area for each of the SIP elements 
listed in this proposal, including (but not limited to) emissions 
statement regulations, nonattainment NSR, and vehicle I/M programs, 
upon revision of the NAAQS, and they are due based on the timeframes 
provided in CAA section 182 as measured from the effective date of 
designation.
    The EPA interprets the CAA to require an air agency to provide a 
SIP submission to meet each nonattainment area planning requirement for 
the 2015 ozone NAAQS. Many air agencies may already have regulations to 
address certain requirements in place due to nonattainment designations 
for a prior ozone NAAQS. Air agencies should review any existing 
regulation that was previously approved by the EPA to determine whether 
it is sufficient to fulfill obligations triggered by any revised ozone 
NAAQS. In cases where a previously-approved provision is modified for 
any reason, or where no provision exists, air agencies must provide the 
new or modified provision as a SIP submission. This would include new 
or modified RACT provisions for states with nonattainment areas and 
states in an OTR, which must be reviewed to ensure that emissions from 
affected stationary sources are appropriately controlled. However, 
where an air agency believes that an existing regulation is adequate to 
meet the nonattainment requirements of CAA section 182 (or OTR RACT 
requirements of CAA section 184) for a revised ozone NAAQS, that air 
agency's SIP submission may provide a written statement of the 
rationale for that determination in lieu of submitting new revised 
regulations. For example, a state may have an emissions statement 
regulation (per CAA section 182(a)(3)(B)) that has been previously 
approved by the EPA for a prior ozone NAAQS that covers all of the 
state's nonattainment areas and relevant classes and categories of 
sources for the 2015 ozone NAAQS, and is likely to be sufficient for 
purposes of the emissions statement requirement for the 2015 ozone 
NAAQS. The EPA has taken action on similar written statements. See 80 
FR 48036, 48040 (explaining that EPA is approving Georgia's 
certification that the state's previously approved regulation meets the 
requirements of CAA section 182(a)(3)(B) for the 2008 ozone standards). 
Other previously-approved nonattainment SIP elements that may be 
sufficient for purposes of an area that has been designated 
nonattainment for a revised NAAQS might include (but are not 
necessarily limited to): Nonattainment NSR; vehicle I/M programs; and 
clean fuels requirement for boilers.
    An air agency choosing to provide a written statement to meet the 
submission requirement of the CAA must provide the statement to the EPA 
as a SIP submission in accordance with CAA section 110 and 40 CFR 
51.102, 103 and Appendix V. An air agency should identify the related 
applicable requirements and how each is met for the revised ozone NAAQS 
by the regulation previously approved for a prior ozone NAAQS. The 
purpose of the statement is to demonstrate compliance with the 
nonattainment plan requirements for the new NAAQS. These written 
statements must be treated in the same manner as any SIP submission and 
must be provided to the EPA in accordance with applicable SIP 
submission requirements and deadlines.

B. Applicability of Existing NAAQS Implementation Provisions in 40 CFR 
Part 51

    The EPA is proposing to retain its existing general requirement 
that establishes the applicability of 40 CFR part 51 to the current and 
prior ozone NAAQS. The general applicability of 40 CFR part 51 to the 
2008 ozone NAAQS is codified in 40 CFR 51.1101, and requires that the 
provisions in subparts A through X of part 51 apply to areas to the 
extent they are not inconsistent with the specific implementation 
provisions for the 2008 standards (i.e., subpart AA of part 51). 
Subparts A through X of part 51 \8\ include generally applicable 
requirements for preparation, adoption, and submittal of implementation 
plans, as well as specific implementation provisions for the 1997 8-
hour ozone NAAQS (codified in subpart X). The EPA is proposing that the 
same requirements apply for purposes of the 2015 ozone NAAQS at 40 CFR 
51.1301, except that the listing of potentially applicable subparts 
would include the addition of subpart AA of part 51 (i.e., subparts A 
through AA).
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    \8\ Excluding subpart Z (Provisions for Implementation of 
PM2.5 NAAQS) and subpart BB (Data Requirements for 
Characterizing Air Quality for the Primary Sulfur Dioxide 
(SO2) NAAQS).
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C. General Classification and Nonattainment Area Planning Provisions

    The EPA is proposing to retain its existing general classification 
and nonattainment area planning provisions, which are codified for the 
2008 ozone NAAQS in 40 CFR 51.1102. These provisions require that 
designated areas be classified in accordance with CAA section 181 
(classifications and attainment dates), as interpreted in 40 CFR 
51.1103(a), and that designated areas will be subject to the applicable 
planning requirements of subpart 2 of part D of title I of the CAA 
(additional provisions for ozone nonattainment areas). The EPA is 
proposing to retain the same general requirements for the 2015 ozone 
NAAQS, without revision, and codify them at 40 CFR 51.1302 and 
51.1303(a).

D. Redesignation to Nonattainment Following Initial Designations

    The EPA is proposing to retain its existing requirements for areas 
initially designated attainment for the current ozone NAAQS and 
subsequently redesignated to nonattainment for the same standards, 
which are codified for the 2008 ozone NAAQS in 40 CFR 51.1106. These 
provisions generally allow an extension of any absolute, fixed date for 
SIP requirements under part 51--excluding attainment dates--equal to 
the length of time between the effective date of the initial 
designation for the NAAQS and the effective date of redesignation, 
unless otherwise provided in the implementation provisions for those 
standards. The maximum attainment date for a redesignated area would be 
based on the area's classification (see Section IV.A of this preamble 
for discussion of classification thresholds and attainment dates). The 
EPA is proposing to retain the same requirements for the 2015 ozone 
NAAQS, without revision.

[[Page 81280]]

E. Determining Eligibility for 1-Year Attainment Date Extensions for 
the 2015 Ozone NAAQS Under CAA Section 181(a)(5)

    The EPA is proposing to retain its existing eligibility criteria 
for 1-year attainment date extensions under CAA section 181(a)(5), 
which are codified for the 2008 ozone NAAQS in 40 CFR 51.1107. An area 
that fails to attain a specific ozone NAAQS by its attainment date 
would be eligible for the first 1-year extension if, for the attainment 
year, the area's fourth highest daily maximum 8-hour average is at or 
below the level of the standards. The area would be eligible for the 
second 1-year extension if the area's fourth highest daily maximum 8-
hour value, averaged over both the original attainment year and the 
first extension year, is at or below the level of the standards. For 
the second 1-year extension, the area's fourth highest daily maximum 8-
hour average for each year (the attainment year and the first extension 
year) must be determined using the monitor which, for that year, has 
the fourth highest daily maximum 8-hour average of all the monitors 
that represent that area (i.e., the area's fourth highest daily maximum 
8-hour average for each year could be derived from a different monitor) 
(see 80 FR 12292; March 6, 2015). The EPA is proposing to retain the 
same general eligibility criteria for the 2015 ozone NAAQS, without 
revision.
    We are also restating in this preamble that, in addition to 
demonstrating that an area meets these general eligibility criteria, an 
air agency must demonstrate that it has complied with all requirements 
and commitments pertaining to the area in the applicable SIP, per CAA 
section 181(a)(5)(A). Given the state and federal partnership in 
implementing the CAA, it is reasonable for the EPA to interpret CAA 
section 181(a)(5)(A) as permitting the agency to rely upon the 
certified statements of its state counterparts, and the EPA has long 
interpreted the provision to be satisfied by such statements.\9\ In 
practice, in conjunction with a request for an extension, a state air 
agency's Executive Officer, or other senior individual with equivalent 
responsibilities, signs and affirms that their state is complying with 
their applicable federally-approved SIP.
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    \9\ See memorandum signed by D. Kent Berry, Acting Director, Air 
Quality Management Division, ``Procedures for Processing Bump Ups 
and Extension Requests for Marginal Ozone Nonattainment Areas.'' 
U.S. EPA, February 3, 1994.
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F. Modeling and Attainment Demonstration Requirements

    The EPA is proposing to retain its existing modeling and attainment 
demonstration requirements, which are codified for the 2008 ozone NAAQS 
in 40 CFR 51.1108, and to establish criteria and due dates for 
attainment demonstrations and implementation of control measures. Due 
dates for attainment demonstrations are established relative to the 
effective date of area designations, and all control measures in the 
attainment demonstration must be implemented no later than the 
beginning of the attainment year ozone season, notwithstanding specific 
RACT and/or RACM implementation deadline requirements. For reference, 
the final 2008 Ozone NAAQS SIP Requirements Rule provides an extensive 
discussion of attainment demonstration elements and related modeling 
protocols (80 FR 12268; March 6, 2015). The EPA's current procedures 
for modeling are well developed and described in the EPA's ``Draft 
Modeling Guidance for Demonstrating Attainment of Air Quality Goals for 
Ozone, PM2.5, and Regional Haze'' (December 2014).\10\ The 
EPA is proposing to retain the same modeling and attainment 
demonstration requirements for the 2015 ozone NAAQS, based on the 
current approach articulated in the final 2008 Ozone NAAQS SIP 
Requirements Rule.
---------------------------------------------------------------------------

    \10\ Modeling guidance, tools, and supporting documents for SIP 
attainment demonstration are available at: http://www3.epa.gov/scram001/guidance_sip.htm.
---------------------------------------------------------------------------

G. Requirements for RFP

    The EPA is proposing to retain its existing RFP requirements and to 
add new regulatory provisions codifying statutory requirements for RFP 
milestone compliance demonstrations (MCDs) (see Section IV.C of this 
preamble). The EPA is also seeking comment on requiring states to use 
the year of an area's designation as nonattainment as the baseline year 
for the emission inventory for the RFP requirement.
    The RFP requirements for the 2008 ozone NAAQS are codified in 40 
CFR 51.1110 and require that nonattainment SIPs provide for the annual 
incremental emission reductions needed to ensure attainment of the 
NAAQS. The provisions in 40 CFR 51.1110 are organized by the following 
major subjects: Submission deadline for SIP revisions; RFP requirements 
for affected areas; \11\ creditability of emission control measures; 
creditability of out-of-area emissions reductions; \12\ calculation of 
non-creditable emissions reductions; and baseline emission inventories 
for RFP plans. For reference, the final 2008 Ozone NAAQS SIP 
Requirements Rule provides an extensive discussion of the EPA's 
rationale and approach for how air agencies can provide for RFP in 
their nonattainment SIPs (80 FR 12271; March 6, 2015).
---------------------------------------------------------------------------

    \11\ 40 CFR 51.1110(a)(2)-(4) establish three separate sets of 
RFP requirements for: (1) Areas with an approved 1-hour or 1997 
ozone NAAQS 15 percent VOC rate of progress (ROP) plan; (2) areas 
for which an approved 15 percent VOC ROP plan for the 1-hour or 1997 
ozone NAAQS exists for only a portion of the area; and (3) areas 
without an approved 1-hour or 1997 ozone NAAQS 15 percent VOC ROP 
plan.
    \12\ Per 40 CFR 51.1110(a)(6), creditable emission reductions 
for fixed percentage reduction RFP must be obtained from sources 
within the nonattainment area.
---------------------------------------------------------------------------

    The EPA is proposing to retain the same RFP approach and 
requirements for the 2015 ozone NAAQS, except that they would also 
apply to areas with approved RFP plans for the 2008 ozone NAAQS, in 
addition to the 1-hour and 1997 standards. This proposed approach 
includes continuing to state that the baseline year for RFP should be 
the calendar year for the most recently available triennial emission 
inventory at the time ROP/RFP plans are developed (e.g., 2017 for 
initial designations effective in 2018), but states may elect an 
earlier alternate year to be used to recognize investments in 
implementing early reductions to achieve improved air quality. We 
propose that states may use an alternate year (i.e., other that 2017) 
between the year of the revised NAAQS issuance (2015) and the year in 
which nonattainment designation is effective. However, the EPA is 
inviting comment on an alternate approach of requiring that states use 
the year of the effective date of an area's designation as the baseline 
year for the emission inventory for the RFP requirements.
    The EPA is proposing to codify our existing interpretation of 
statutory requirements for RFP MCD, which would be codified into 
specific provisions of the RFP requirements discussed here (see Section 
IV.C of this preamble).

H. Requirements for RACT and RACM

1. RACT
    The EPA is proposing to retain its existing general RACT 
requirements, and to add new deadline requirements for certain RACT SIP 
revisions (see Section IV.D of this preamble). The general RACT 
requirements for the 2008 ozone NAAQS, which are codified in 40 CFR 
51.1112(a) and (b), address the content and timing of RACT SIP

[[Page 81281]]

submittals and implementation, and major source criteria for RACT 
applicability.\13\ Underlying these general RACT requirements are well-
established EPA policies and guidance, including existing control 
techniques guidelines (CTGs) and alternative control techniques 
(ACTs).\14\ For reference, the final 2008 Ozone NAAQS SIP Requirements 
Rule provides an extensive discussion of the EPA's current rationale 
and approach for how air agencies can provide for RACT in their 
nonattainment SIPs (80 FR 12278; March 6, 2015). With the exception of 
new implementation deadlines for certain RACT SIP revisions (see 
Section IV.D of this preamble), the EPA is proposing to retain the same 
RACT requirements for the 2015 ozone NAAQS, based on the current 
rationale and approach articulated in the final 2008 Ozone NAAQS SIP 
Requirements Rule (80 FR 12278; March 6, 2015).
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    \13\ The EPA has defined RACT as the lowest emission limitation 
that a particular source is capable of meeting by the application of 
control technology that is reasonably available considering 
technological and economic feasibility (December 9, 1976, memorandum 
from Roger Strelow, Assistant Administrator for Air and Waste 
Management, to Regional Administrators, ``Guidance for Determining 
Acceptability of SIP Regulations in Non-Attainment Areas'' and also 
in 44 FR 53762; September 17, 1979). Availability and feasibility 
may differ across sources in the same category (June 19, 1985, 
memorandum from John Calcagni, Chief, Economic Analysis Branch, to 
G.T. Helms, ``Criteria for Determining RACT in Region IV.'').
    \14\ The EPA's CTGs and ACTs are available at: https://www3.epa.gov/airtoxics/ctg_act.html.
---------------------------------------------------------------------------

2. RACM
    The EPA is proposing to retain its existing RACM requirements, and 
to clarify the requirement under CAA section 172(c)(6) that air 
agencies also consider the impacts of emissions from sources outside an 
ozone nonattainment area but within a state's boundaries, and to 
require such other measures for emissions reductions from these 
intrastate sources if needed to attain the ozone NAAQS by the 
applicable attainment date (see Section IV.E of this preamble). The 
general RACM requirements for the 2008 ozone NAAQS are codified in 40 
CFR 51.1112(c). For reference, the final 2008 Ozone NAAQS SIP 
Requirements Rule describes the EPA's current rationale and approach 
for how air agencies can provide for RACM in their nonattainment SIPs 
(80 FR 12282; March 6, 2015). The EPA interprets the RACM provision to 
require a demonstration that an air agency has adopted all reasonable 
measures (including RACT) to meet RFP requirements and to demonstrate 
attainment as expeditiously as practicable and, thus, that no 
additional measures that are reasonably available will advance the 
attainment date or contribute to RFP for the area.15 16 17 
As the EPA has previously stated in the final 2008 Ozone NAAQS SIP 
Requirements Rule,\18\ in determining the attainment date that is as 
expeditious as practicable, an air agency should consider impacts on 
the nonattainment area of intrastate transport of pollution from 
sources within its jurisdiction, and potential reasonable measures to 
reduce emissions from those sources. Further, the EPA requires that air 
agencies should consider all available measures, including those being 
implemented in other areas, but must adopt measures for an area only if 
those measures are economically and technologically feasible and will 
advance the attainment date or are necessary for RFP. The EPA is 
proposing to retain its existing general RACM requirements for the 2015 
ozone NAAQS--including the requirement to consider measures that 
address intrastate transport--based on the current rationale and 
approach articulated in the final 2008 Ozone NAAQS SIP Requirements 
Rule, and the requirements of CAA section 172(c)(6).
---------------------------------------------------------------------------

    \15\ ``State Implementation Plans; General Preamble for Proposed 
Rulemaking on Approval of Plan Revisions for Nonattainment Areas'' 
44 FR 20375 (April 4, 1979). ``State Implementation Plans; General 
Preamble for the Implementation of Title I of the Clean Air Act 
Amendments of 1990; Proposed Rule.'' 57 FR 13560 (April 16, 1992).
    \16\ ``Guidance on the Reasonably Available Control Measures 
(RACM) Requirement and Attainment Demonstration Submissions for 
Ozone Nonattainment Areas.'' John S. Seitz, Director, Office of Air 
Quality Planning and Standards. November 30, 1999. Available at: 
http://www3.epa.gov/ttn/caaa/t1/memoranda/revracm.pdf.
    \17\ Memorandum of December 14, 2000, from John S. Seitz, 
Director, Office of Air Quality Planning and Standards, re: 
``Additional Submission on RACM from States with Severe One-Hour 
Ozone Nonattainment Area SIPs.'' Available at: http://www3.epa.gov/ttn/caaa/t1/memoranda/121400_racmmemfin.pdf.
    \18\ See the final SIP Requirements Rule for the 2008 ozone 
NAAQS (80 FR 12264, 12270; March 6, 2015).
---------------------------------------------------------------------------

    The final 2008 Ozone NAAQS SIP Requirements Rule also recommended 
that if wildfire impacts are significant in an area and contribute to 
exceedances of the standard, then air agencies should consider RACM for 
wildfires (which could include the use of prescribed fires). As 
discussed in Section V.A of this preamble, the EPA is revising its 
recommendation, such that prescribed fire and related wildland 
management practices instead be addressed outside of the regulatory 
framework of nonattainment planning.

I. CAA Section 182(f) NOX Exemption Provisions

    The EPA is proposing to retain its existing CAA section 182(f) 
NOX exemption provisions, which are codified for the 2008 
ozone NAAQS in 40 CFR 51.1113. These provisions allow a person or an 
air agency to petition the Administrator for an exemption from 
NOX obligations under CAA section 182(f) for any area 
designated nonattainment for the 2008 ozone standards and for any area 
in a CAA section 184 OTR. 40 CFR 51.1113(c) stipulates that 
NOX exemptions granted for previous 1-hour or 1997 ozone 
NAAQS do not relieve an area from CAA section 182(f) NOX 
obligations under the 2008 standards (see 80 FR 12294; March 6, 2015). 
The EPA is proposing to retain the same requirements for the 2015 ozone 
NAAQS, stipulating that NOX exemptions granted for any prior 
ozone NAAQS do not relieve an area from CAA section 182(f) 
NOX obligations under a specific revised ozone NAAQS. 
Consistent with current EPA policy, existing NOX waivers for 
the 2008 ozone standards would remain valid until area designations for 
the 2015 NAAQS become effective, and we encourage air agencies to 
consult the EPA's guidance on appropriate documentation for new waiver 
requests.\19\
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    \19\ Memorandum dated January 14, 2005, ``Guidance on Limiting 
Nitrogen Oxides (NOX) Requirements Related to 8-Hour 
Ozone Implementation'' from Stephen D. Page, Director, Office of Air 
Quality Planning and Standards, to Air Directors, Regions I-X. 
Available at: http://www3.epa.gov/ttn/caaa/t1/memoranda/guide8hr-oz.pdf.
---------------------------------------------------------------------------

J. General Nonattainment NSR Requirements

    With one significant exception, the EPA is proposing to retain its 
NNSR requirements contained at 40 CFR 51.165 and part 51 Appendix S, 
which contain provisions for the preconstruction review and issuance of 
permits to proposed new major stationary sources and major 
modifications locating in ozone nonattainment areas. The one exception 
pertains to a proposal to address IPT for ozone. As explained in 
Section IV.F of this preamble, the EPA is proposing to confirm its 
policy on ozone IPT, which is currently codified at 40 CFR 
51.165(a)(11) and part 51 Appendix S, section IV.G.5, in response to a 
petition for reconsideration. A basic understanding about how the NNSR 
requirements would otherwise apply to the 2015 ozone NAAQS can be 
obtained from the preamble discussion at Section VIII.C in the final 
rule for the setting of

[[Page 81282]]

the 2015 Ozone NAAQS. See 80 FR 65442 (October 26, 2015).
    The EPA proposes to codify NNSR requirements for the ozone NAAQS at 
40 CFR 51.1314. These provisions would require that for each 
nonattainment area an air agency must submit an NNSR plan or plan 
revision for the 2015 ozone NAAQS no later than 36 months after the 
effective date of the area's nonattainment designation for the 2015 
ozone NAAQS. As discussed in Section IV.B of this preamble, we are 
proposing two options for revoking the 2008 ozone NAAQS. The first 
approach to revoking the 2008 ozone NAAQS (option 1) would parallel the 
approach used in revoking the 1-hour and 1997 ozone NAAQS, and would 
require that a set of protective anti-backsliding requirements be 
promulgated for all areas that are designated nonattainment for both 
the 2008 NAAQS and the 2015 NAAQS. Under the second approach (option 
2), the 2008 ozone NAAQS would not be revoked in any area designated 
nonattainment for the 2008 ozone NAAQS until that area is redesignated 
to attainment with an approved CAA section 175A 10-year maintenance 
plan; but in no case earlier than 1 year after the effective date of 
designation for the 2015 ozone NAAQS. If the EPA were to revoke the 
2008 ozone NAAQS according to proposed option 1, the EPA is also 
proposing conforming changes to the existing anti-backsliding 
provisions at 40 CFR 51.165(a)(12) and part 51 Appendix S section VII. 
See Section IV.B of this preamble for a discussion of the conforming 
revisions to the anti-backsliding provisions addressing the proposed 
revocation of the 2008 ozone NAAQS under option 1.

K. Ambient Monitoring Requirements

    The EPA is not proposing any changes to the existing ozone ambient 
monitoring requirements are codified in 40 CFR part 58. Monitoring rule 
amendments published on October 17, 2006, (71 FR 61236) established 
minimum ozone monitoring requirements based on population and levels of 
ozone in an area to better prioritize monitoring resources. The minimum 
monitoring requirements are contained in Table D-2 of appendix D to 
part 58. The Photochemical Assessment Monitoring Station (PAMS) 
program, required by CAA section 182(c)(1), collects enhanced ambient 
air measurements. The rulemaking for the final 2015 ozone NAAQS 
included revisions to the PAMS requirements (80 FR 65416; October 26, 
2015). The revisions were intended to provide a more spatially 
dispersed network, reduce potential redundancy, and improve data value 
while providing monitoring agencies flexibility in collecting 
additional information needed to understand their specific ozone 
issues.

L. Requirements for an OTR

    The EPA is proposing to retain its existing OTR requirements, and 
to add new deadline requirements for certain RACT SIP revisions (see 
Section IV.D of this preamble). The OTR requirements for the 2008 ozone 
NAAQS, which are codified in 40 CFR 51.1116, establish the general 
applicability of CAA sections 176A (interstate transport commissions) 
and 184 (control of interstate ozone air pollution), and stipulate the 
criteria and timing for RACT SIP submittals and RACT implementation for 
those portions of states located in an OTR (see 80 FR 12295; March 6, 
2015). With the exception of additional submission and implementation 
deadlines for certain RACT SIP revisions (see Section IV.D of this 
preamble), the EPA is proposing to retain the same requirements for the 
2015 ozone NAAQS, without revision.

M. Fee Programs for Severe and Extreme Nonattainment Areas That Fail To 
Attain

    The EPA is proposing to retain its existing fee program SIP 
submission requirements, which are codified for the 2008 ozone NAAQS in 
40 CFR 51.1117, and apply to each area classified Severe or Extreme for 
that standard. Affected areas must submit a SIP revision that meets the 
requirements of CAA section 185 (Enforcement for Severe and Extreme 
ozone nonattainment areas for failure to attain) within 10 years of the 
effective date of designation and classification as a Severe or Extreme 
area. The EPA is proposing to retain the same SIP submission 
requirements for the 2015 ozone NAAQS, without revision.

N. Applicability

    The EPA is proposing to retain the provision that establishes 
applicability of the current ozone NAAQS implementation provisions, 
which is codified for the 2008 ozone NAAQS in 40 CFR 51.1119. The 
provision states that the current provisions (subpart AA of part 51) 
shall replace those for the previous 1997 standards (subpart X of part 
51) after revocation of the 1997 NAAQS, except for anti-backsliding 
purposes. The EPA is proposing to retain the same requirements for the 
2015 ozone NAAQS, except that the proposed new implementation 
provisions (to be codified in the new subpart CC of part 51) would 
replace those for the 2008 ozone NAAQS (subpart AA) if the 2008 
standards are revoked for all purposes, except for anti-backsliding 
purposes. The proposed revocation of, and anti-backsliding requirements 
for, the 2008 ozone NAAQS are discussed in Section IV.B of this 
preamble.

IV. Provisions of the 2008 Ozone NAAQS Implementing Regulations To Be 
Retained With Specific Revisions

    For purposes of the 2015 ozone NAAQS, we are proposing to 
promulgate some provisions that are similar to those for the 2008 ozone 
NAAQS, but with minor modifications to reflect application to the 2015 
ozone NAAQS, as explained later. The existing classification and SIP 
requirement provisions for the 2008 standards, and revocation of the 
1997 standards are codified at subpart AA of 40 CFR part 51, and the 
corresponding provisions for the 2015 standards would be codified at 
the new subpart CC of part 51. These proposed revisions reflect 
classification thresholds and attainment deadlines relevant to the 2015 
ozone standards; MCD for RFP; submission and implementation deadlines 
for RACT SIP revisions; the consideration of intrastate pollution 
sources outside of a nonattainment area for attainment planning; NNSR 
IPT for ozone; emissions inventories and emissions statements; and 
revoking the 2008 standards. The EPA welcomes comment on the following 
proposed provisions.

A. Application of Classification and Attainment Date Provisions in CAA 
Section 181 to Areas Subject to Subpart 2 of Part D of Title I of the 
CAA

1. Background and Summary of Proposal
    The EPA is proposing thresholds for classifying nonattainment areas 
for the 2015 ozone NAAQS, and is proposing the timing of attainment 
dates for each classification. We are also proposing to grant voluntary 
reclassification to six California areas designated as nonattainment 
for the 1997 ozone NAAQS that were voluntarily reclassified under that 
NAAQS and the subsequent 2008 ozone standards. Each area designated as 
nonattainment for the 2015 ozone NAAQS will be classified at the same 
time as the area is designated by the EPA. Accordingly, the EPA intends 
to finalize classification thresholds on or before the date that it 
issues area designations.

[[Page 81283]]

2. Initial Area Designations for the 2015 Ozone NAAQS
    After promulgating a new or revised NAAQS, the EPA considers air 
agencies' recommendations for initial area designations (i.e., as 
nonattainment, attainment, or unclassifiable). Area designations 
establish which areas are meeting the NAAQS (attainment) and which 
areas are not meeting the NAAQS (nonattainment), and the boundaries for 
those areas. Areas designated unclassifiable cannot be classified as 
meeting or not meeting the NAAQS based on available information. Based 
on the schedule provided in section 107(d) of the CAA, states are 
required to submit designation recommendations for every area in the 
state to the EPA by no later than October 1, 2016, which is 1 year 
after the promulgation date of the 2015 ozone NAAQS.\20\ In the event 
that the EPA intends to modify an air agency's recommendation, the EPA 
will notify the air agency no less than 120 days prior to issuing 
designations.\21\ The CAA requires the EPA to promulgate designations 
no later than 2 years after the October 1, 2015, promulgation of the 
revised ozone NAAQS. Such period may be extended for up to one year in 
the event the Administrator has insufficient information to promulgate 
the designations.
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    \20\ Area designations guidance for the 2015 ozone NAAQS 
available at: https://www.epa.gov/ozone-designations/epa-guidance-area-designations-2015-ozone-naaqs.
    \21\ While CAA section 107, which governs the process for 
initial area designations, specifically addresses states, the EPA 
intends to follow the same process for tribes to the extent 
practicable, pursuant to section 301(d) of the CAA regarding tribal 
authority and the Tribal Authority Rule (TAR) (63 FR 7254; February 
12, 1998).
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3. Nonattainment Area Classifications
    In accordance with CAA section 181(a)(1), each area designated as 
nonattainment for the 2015 ozone NAAQS will be classified at the time 
of designation. The planning and emission reduction requirements as 
well as the maximum attainment date for each area are based on that 
area's classification.
    Under Subpart 2 of part D of title I of the CAA, state planning and 
emissions control requirements for ozone are determined, in part, by a 
nonattainment area's classification. These requirements apply in 
addition to the general SIP planning requirements applicable to all 
nonattainment areas under subpart 1 of part D. Under CAA subpart 2, 
ozone nonattainment areas are classified based on the severity of their 
ozone levels (as determined based on the area's ``design value,'' 
(DV)).\22\ Nonattainment areas with a ``lower'' classification have 
ozone levels that are closer to the standard than areas with a 
``higher'' classification. Subpart 2 provides an increasing amount of 
maximum time from the date of designation to attain the standards for 
the progressively higher classifications: Marginal (3 years), Moderate 
(6 years), Serious (9 years), Severe-15 (15 years), Severe-17 (17 
years) and Extreme (20 years).
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    \22\ The air quality DV for the 8-hour ozone NAAQS is the 3-year 
average of the annual fourth highest daily maximum 8-hour average 
ozone concentration for a specific monitor. When an area has 
multiple monitors, the area's DV is determined by the individual 
monitor with the highest DV.
---------------------------------------------------------------------------

    Air agencies with areas in the lower classification levels have 
fewer mandatory air quality planning and control requirements than 
those in higher classifications. For instance, air agencies with a 
Marginal area are only required to adopt an emissions statement rule 
for major stationary sources, submit a base year emissions inventory, 
follow the general and transportation conformity requirements in CAA 
section 176(c), and implement a nonattainment area preconstruction 
permit program (NNSR). Air agencies with a Moderate area are subject to 
the Marginal area requirements; in addition air agencies must submit a 
SIP revision that provides for a 15 percent emissions reduction from 
the RFP baseline year within 6 years after the baseline year, and a 
demonstration that the area will attain as expeditiously as 
practicable, but not later than 6 years after designation. Air agencies 
with a Moderate area must also adopt (and submit for EPA approval) 
certain emissions control requirements, such as RACT, a basic vehicle 
I/M program if the area meets the applicable population thresholds, and 
provisions for increased offsets for new or modified sources under the 
state's NNSR program. The higher classifications similarly require 
additional emissions control programs and stricter NNSR requirements 
beyond those required for a Moderate area. In addition, the major 
source threshold for permitting, RACT and emissions reporting decreases 
progressively from 100 tons per year (tpy) for Marginal areas to 10 tpy 
for Extreme areas.

4. Proposed Classification Thresholds

    a. Background. The CAA was amended in 1990 to add specific 
provisions that apply to ozone nonattainment areas. These include 
timelines for both planning and implementation, and requirements for 
specific programs to reduce emissions that vary based on an area's 
classification. The ozone standard in effect at the time of the 1990 
CAA amendments was a 1-hour exceedance-based standard of 0.12 ppm.\23\ 
Accordingly, the classification provisions in Table 1 in section 181 of 
subpart 2 of the CAA (also referred to herein as the ``subpart 2 
classification table'') are specific to that 1-hour standard. In 1997, 
the EPA revised both the form and level of the ozone NAAQS to a 3-year 
average of annual fourth highest daily maximum 8-hour averages.\24\ In 
a subsequent rulemaking, the EPA adapted the CAA's 1-hour 
classification thresholds to the new 8-hour standard \25\ and used the 
new 8-hour threshold values to classify certain areas designated 
nonattainment for the 1997 8-hour NAAQS. We translated the 
classification thresholds in the subpart 2 classification table from 1-
hour DVs to 8-hour DVs based on the percentage by which each 
classification threshold in the table exceeds the 1-hour ozone NAAQS. 
We noted that these percentages, as established by Congress in 1990, 
set the classification thresholds at certain percentages or fractions 
above the level of the standard.\26\ The EPA refers to this method as 
the ``percent-above-the-standard'' method. This approach for 
translating the CAA's 1-hour threshold values to 8-hour threshold 
values was challenged in litigation and was upheld by the Court. See 
South Coast Air Quality Management District v. Environmental Protection 
Agency, 472 F.3d at 896-898. After analyzing various alternative 
options for establishing classification thresholds, the EPA retained 
the ``percent-above-the-standard'' approach in its final implementing 
regulations for the 2008 ozone NAAQS.\27\
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    \23\ For additional discussion on the 1-hour ozone NAAQS and its 
associated area designations and classifications, see 56 FR 56695 
(November 6, 1991).
    \24\ See 40 CFR Appendix I.
    \25\ Referred to as the Phase 1 Rule, see 69 FR 23956 to 23966 
and part 51, subpart X at 51.903.
    \26\ The upper thresholds of the Marginal, Moderate, Serious and 
Severe classifications are precise percentages or fractions above 
the level of the standard, namely 15 percent (3/20ths more than the 
standard), 33.33 percent (one-third more than the standard), 50 
percent (one-half more than the standard), and 133.3 percent (one 
and one-third more than the standard).
    \27\ See 77 FR 30162 to 30164 (May 21, 2012).
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    b. Proposed classification threshold method. In this action, we are 
proposing to use the same ``percent-above-the-standard'' methodology as 
was used for establishing thresholds for classifications for the 1997 
and 2008 8-hour ozone standards. The percent-above-the-standard method 
is a simple and straightforward method for establishing classification 
thresholds that is based on principles inherent in

[[Page 81284]]

the subpart 2 classification table itself. The principles include the 
following:
     Areas are grouped by the severity of their air quality 
problem as characterized by the degree of nonattainment based on their 
DV.
     Classification would occur ``by operation of law'' without 
relying on the EPA exercising discretion for individual situations.\28\
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    \28\ Prior to any application of the 5 percent adjustment 
provision under CAA section 181(a)(4) which may occur in the 90-day 
period following initial designations and classifications). See 
Section IV.A.5 of this preamble for details on how the EPA proposes 
to interpret previous voluntary reclassification requests for the 
1997 ozone NAAQS under the 2015 ozone NAAQS.
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     Classification thresholds are derived from the structure 
or logic of the CAA's nonattainment area planning and control 
requirements, including the subpart 2 classification table, and 
consistent with the overall goal of subpart 2 of attaining the 
standards as expeditiously as practicable. At the same time, the CAA 
provides mechanisms for voluntary and mandatory reclassification to a 
higher classification, in the event that the initial maximum attainment 
date for an area is determined to be insufficient to achieve the 
standards.
    In developing its proposed Classifications Rule for the 2008 ozone 
standards, the EPA evaluated other options for classifying ozone 
nonattainment areas but did not find them to be a more reasonable 
interpretation of the Act's classification provisions, and did not 
propose or solicit comment on them in the rule.\29\
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    \29\ Docket #EPA-HQ-OAR-2010-0885 includes a background 
information document prepared for the proposed rule titled, 
Additional Options Considered for Classification of Nonattainment 
Areas under the Proposed 2008 Ozone NAAQS (January 2012).
---------------------------------------------------------------------------

    Under the proposed percent-above-the-standard method, the 
classification thresholds in the subpart 2 classification table would 
be translated into a corresponding set of 8-hour DVs that are the same 
percentages above the 2015 ozone NAAQS as the DV levels in the subpart 
2 classification table are above the 1-hour ozone NAAQS. For example, 
the threshold separating the Marginal and Moderate classifications in 
the subpart 2 classification table (0.138 ppm) is 15 percent above the 
1-hour ozone NAAQS (0.12 ppm). Thus, under this approach, the threshold 
separating the Marginal and Moderate classifications for the 2015 ozone 
NAAQS would be 0.070 ppm plus 15 percent, or 0.081 ppm. Table 1 depicts 
this proposed translation for classifications as it would apply for the 
2015 ozone NAAQS.

  Table 1--Subpart 2 1-Hour Ozone Design Value Classification Table Translation to 8-Hour Design Values for the
                                          2015 Ozone NAAQS of 0.070 PPM
----------------------------------------------------------------------------------------------------------------
                                                                                Percent above 1-   8-hour ozone
             Area class                                         1-Hour design      hour ozone      design value
                                                                 value (ppm)         NAAQS            (ppm)
----------------------------------------------------------------------------------------------------------------
Marginal............................  From up to \a\.........            0.121            0.833            0.071
                                                                         0.138               15            0.081
Moderate............................  From up to \a\.........            0.138               15            0.081
                                                                         0.160           33.333            0.093
Serious.............................  From up to \a\.........            0.160           33.333            0.093
                                                                         0.180               50            0.105
Severe-15...........................  From up to \a\.........            0.180               50            0.105
                                                                         0.190           58.333            0.111
Severe-17...........................  From up to \a\.........            .0190           58.333            0.111
                                                                         0.280          133.333            0.163
Extreme.............................  Equal to or above......            0.280          133.333            0.163
----------------------------------------------------------------------------------------------------------------
\a\ But not including.

    Based on our analysis of air quality information from 2013-2015, we 
estimate that approximately 57 ``hypothetical nonattainment areas'' had 
ambient ozone concentrations exceeding the 2015 ozone NAAQS. We use 
these 57 ``hypothetical nonattainment areas'' for purposes of the 
following discussion. These hypothetical areas are intended to 
illustrate the potential distribution of areas into the proposed 
classifications. The actual number of total nonattainment areas, 
boundaries of those areas, and the classification of each area will 
depend on decisions made in the separate designations process under CAA 
section 107(d) and we anticipate that these decisions will be based on 
air quality information from 2014-2016. Applying the proposed 
thresholds in Table 1, the 57 hypothetical nonattainment areas based on 
2013-2015 air quality data would yield the distribution in each 
classification as shown in Table 2.

       Table 2--Number of Hypothetical Nonattainment Areas in Each
  Classification Under the 2015 Ozone NAAQS: Percent-Above-the-Standard
                                 Method
------------------------------------------------------------------------
                                                            2015 Ozone
                                                               NAAQS
                   Area classification                     (hypothetical
                                                            areas) \a\
------------------------------------------------------------------------
Marginal................................................              47
Moderate................................................               7
Serious.................................................               3
Severe-15...............................................               0
Severe-17...............................................               0
Extreme.................................................               0
                                                         ---------------
    Total...............................................              57
------------------------------------------------------------------------
\a\ Hypothetical nonattainment area classifications do not reflect
  potential voluntary reclassifications of the California areas
  discussed in Section IV.A.5 of the preamble.

    The proposed classification method results in the vast majority of 
nonattainment areas being classified Marginal. It is possible that a 
few areas would have a later maximum statutory attainment date for 
their existing classification under the 2008 ozone NAAQS than they 
would have for their new classification under the 2015 NAAQS. For 
example, an area that would be classified Moderate if designated in 
2017 for the more stringent 2015 ozone NAAQS (with a potential maximum 
statutory attainment date in 2023), may currently be classified Severe 
for the less-stringent 2008 ozone NAAQS (which has a later maximum 
statutory attainment date in 2027).\30\ This issue also arose under the 
previously promulgated 8-hour classification threshold structure for 
the 2008 NAAQS. See Section IV.A.5 of this preamble for additional 
details on how the EPA intends to address previous voluntary 
reclassifications under the 2015 ozone NAAQS.
---------------------------------------------------------------------------

    \30\ As indicated elsewhere in this preamble, the CAA requires 
the EPA to designate areas for the 2015 standard by October 1, 2017. 
Thus, a 6-year attainment deadline would be in 2023.
---------------------------------------------------------------------------

    For areas likely to be classified Marginal with a 3-year attainment 
date

[[Page 81285]]

(e.g., in 2020), a number of federal and state emission reduction 
programs have already been adopted that are expected to provide 
reductions of ozone precursor emissions, both within and upwind of the 
ozone nonattainment areas, lowering peak ozone concentrations by the 
attainment date. Such programs include more stringent emission 
standards for on-road and nonroad vehicles and equipment (with 
associated fleet turnover), regional reductions in power plant 
emissions to address interstate transport, and future programs to 
reduce VOC emissions from oil and gas sources.
5. Reclassification of Nonattainment Areas That Have Voluntarily 
Requested Higher Classifications
    The CAA provides three mechanisms for addressing nonattainment 
areas that may not be able to attain by the attainment date appropriate 
to their classification. First, CAA section 181(a)(4) provides that 
within 90 days of designation and classification, the Administrator may 
exercise discretion to reclassify an area to a higher (or lower) 
classification if its DV is within 5 percent of the DV range of the 
higher (or lower) classification.\31\ Any air agency interested in 
taking advantage of this flexibility should submit a request to the EPA 
in sufficient time for the Administrator to make a determination within 
the 90 days provided.
---------------------------------------------------------------------------

    \31\ Because most areas would be expected to be classified 
Marginal (i.e., the lowest classification) and the few areas that 
would be classified in higher classifications are likely to be 
challenged to attain by the attainment date for the classification 
it receives at the time of designation, we do not anticipate 
receiving requests to reclassify an area to a lower classification.
---------------------------------------------------------------------------

    The second mechanism, provided in CAA section 181(b)(2), requires 
that an area be reclassified to a higher classification (i.e., 
``bumped-up'') if the EPA determines that the area has failed to attain 
the standard by the applicable attainment date.
    The third mechanism, provided in CAA section 181(b)(3), allows an 
air agency to voluntarily request that the EPA reclassify the area to a 
higher classification. The EPA must approve any such requests. Once an 
area is reclassified to a higher classification, it becomes subject to 
the associated additional planning and control requirements for that 
higher classification, and must attain the standard no later than the 
maximum attainment date for that classification. Six nonattainment 
areas in California were granted voluntary reclassifications for both 
the 1997 and 2008 ozone standards (77 FR 30165; May 21, 2012).
    The EPA is again proposing to apply a previous voluntary 
reclassification for areas in California to the more stringent 2015 
ozone standards unless the state of California explicitly requests 
otherwise in their comments to this proposed action.\32\ These areas 
are listed in Table 3. We believe this is an appropriate mechanism to 
address the situation for these California areas that were voluntarily 
reclassified for the 1997 ozone NAAQS and previously used this 
mechanism for the 2008 ozone NAAQS to ensure the areas would have an 
attainment date for the more stringent 2015 ozone NAAQS that is no 
earlier than the area's attainment date for the less stringent 2008 
NAAQS. The EPA is proposing this approach in order to minimize burden 
on the state of California and obviate the need to go through the 
voluntary reclassification process again.
---------------------------------------------------------------------------

    \32\ Areas for which California declines voluntary 
reclassification would be classified at the time of designation for 
the 2015 ozone NAAQS based on their DV.

                      TABLE 3--Areas for Which the State of California Requested a Voluntary Reclassification Under the 1997 NAAQS
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                           Hypothetical
                                                               Voluntary              Voluntary              initial             Potential voluntary
                                    Original 1997 ozone   reclassification for   reclassification for     classification     reclassification under 2015
        Nonattainment area         NAAQS classification     1997 ozone NAAQS       2008 ozone NAAQS      under 2015 ozone    ozone NAAQS \a\ (attainment
                                     (attainment date)     (attainment date)      (attainment date)         NAAQS \a\                   date)
                                                                                                        (attainment date)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Los Angeles-South Coast Air Basin  Severe-17 (2021)....  Extreme (2024).......  Extreme (2032).......  Serious (2026).....  Extreme (2037).
San Joaquin Valley...............  Serious (2013)......  Extreme (2024).......  Extreme (2032).......  Serious (2026).....  Extreme (2037).
Riverside County (Coachella        Serious (2013)......  Severe-15 (2019).....  Severe-15 (2027).....  Moderate (2023)....  Severe-15 (2032).
 Valley).
Sacramento Metro.................  Serious (2013)......  Severe (2019)........  Severe-15 (2027).....  Moderate (2023)....  Severe-15 (2032).
Ventura County...................  Moderate (2010).....  Serious (2013).......  Serious (2021).......  Marginal (2020)....  Serious (2026).
Western Mojave...................  Moderate (2010).....  Severe-15 (2019).....  Severe-15 (2027).....  Moderate (2023)....  Severe-15 (2032).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Based on thresholds proposed in this notice and final 2013-2015 design values.

    It is important to note that an air agency may request a voluntary 
reclassification for an area under CAA section 181(b)(3) at any time. 
If the air agency wants a specific higher classification to apply to an 
area at the time of initial designation, the EPA encourages the air 
agency to make such a request prior to or contemporaneous with the 
designation process.
6. Attainment Dates for Nonattainment Areas in Each Classification of 
the 2015 ozone NAAQS
    The EPA is proposing to retain its current approach in establishing 
attainment dates for each nonattainment area classification, which run 
from the effective date of designation. This approach is codified at 40 
CFR 51.1103 for the 2008 ozone NAAQS, and we are proposing to retain 
the same approach for the 2015 ozone NAAQS without revision.
    In the implementing regulations for the 1997 ozone NAAQS, the EPA 
interpreted these timeframes to run from the date that area 
designations and nonattainment classifications (by operation of law) 
became effective (64 FR 23954; April 30, 2004). We adopted an 
alternative approach in the classification regulations for the 2008 
ozone standards, where the attainment dates would be December 31 of the 
year that is the specified number of years in the subpart 2 
classification table after designation (77 FR 30166; May 21, 2012). The 
end of calendar year attainment date was challenged in NRDC v. EPA, 777 
F.3d 456 (D.C. Cir. 2014). On December 23, 2014, the U.S. Court of 
Appeals for the District of Columbia Circuit issued an opinion holding 
that the EPA's decision to run the attainment periods to the end of the 
calendar year in which areas were designated was unreasonable. While

[[Page 81286]]

recognizing that there is a ``gap'' in the statute since the CAA runs 
the attainment periods from the date of enactment of the CAA Amendments 
of 1990, the Court concluded that nothing in the statute or 
congressional intent authorized the EPA to establish the attainment 
dates for designated ozone nonattainment areas as December 31st of the 
relevant calendar years, but rather that Congress's decision to run the 
``. . . attainment periods starting from the designation date'' for the 
ozone standard existing at the time of the 1990 CAA amendments 
``strongly suggests that the same trigger date should apply when 
adapting [applicable attainment dates] to the analogous situation of a 
revised NAAQS.'' 777 F.3d at 466. The EPA subsequently revised its 
regulations for the 2008 ozone NAAQS to follow the same approach used 
for the 1997 ozone NAAQS, and this is codified at 40 CFR 51.1103.
    Consistent with the regulatory approach for both the 1997 and 2008 
ozone NAAQS, we are proposing that the maximum attainment dates for 
nonattainment areas in each classification under the 2015 NAAQS are as 
follows: Marginal--3 years from effective date of designation; 
Moderate--6 years from effective date of designation; Serious--9 years 
from effective date of designation; Severe--15 years (or 17 years) from 
effective date of designation; and Extreme--20 years from effective 
date of designation.

B. Transition From the 2008 Ozone NAAQS to the 2015 Ozone NAAQS and 
Anti-Backsliding Requirements

1. Background and Summary of Proposal
    The EPA is proposing and seeking comment on two alternative 
approaches for revoking the 2008 ozone NAAQS and is also seeking 
comment on whether to revoke the NAAQS at the current time. The first 
approach to revoking the 2008 ozone NAAQS would parallel the approach 
used in revoking the 1-hour and 1997 ozone NAAQS. Under this first 
approach, the 2008 ozone NAAQS would be revoked at essentially the same 
time for all areas of the U.S., and a set of protective anti-
backsliding requirements would be promulgated for all areas that are 
designated nonattainment for the 2008 and 2015 NAAQS as of one year 
after the effective date of designation for the 2015 ozone NAAQS. Under 
the second approach, the 2008 ozone NAAQS would continue to apply in 
any area designated nonattainment for the 2008 ozone NAAQS until that 
area is redesignated to attainment with an approved CAA section 175A 
10-year maintenance plan; but in no case earlier than 1 year after the 
effective date of designation for the 2015 ozone NAAQS. The 2008 ozone 
NAAQS would be revoked in all other areas 1 year after the effective 
date of designation for the 2015 ozone NAAQS.
2. Rationale and Authority
    The EPA believes that both of the proposed options to revoke the 
2008 ozone NAAQS are consistent with the CAA and previous precedent in 
transitioning from a previous NAAQS to a new, more stringent NAAQS, and 
would help ensure that areas designated attainment for the revoked 
NAAQS continue to attain the revoked NAAQS into the future.
    a. Option 1: Revoke the 2008 ozone NAAQS for all purposes in each 
area 1 year after the effective date of the designation for the 2015 
ozone NAAQS. The EPA's first proposed option would revoke the 2008 
ozone NAAQS for all purposes 1 year following the effective date of the 
designations for the 2015 ozone standard. The EPA interprets the CAA 
such that revoking the 2008 ozone NAAQS in an area would require 
appropriate anti-backsliding measures. Therefore, the EPA is proposing 
that anti-backsliding provisions would apply to an area in accordance 
with its designation and its classification for the 2008 (and, if 
applicable, 1997 and 1-hour) ozone NAAQS as of the effective date of 
the revocation of the 2008 ozone NAAQS (a more detailed discussion of 
EPA's proposed approach to anti-backsliding is provided in Section 
IV.B.4 of this preamble). Upon revocation of the 2008 NAAQS, the areas 
that had been initially designated or subsequently redesignated to 
attainment for the 2008 NAAQS prior to its revocation would be subject 
only to the general protections of CAA sections 110(l) and 193, whereas 
areas designated nonattainment for the 2008 NAAQS would also be subject 
to an extensive set of regulatory anti-backsliding provisions 
promulgated in accordance with the principles of CAA section 172(e). 
This approach is consistent with the EPA's established practice in 
transitioning from prior to current ozone NAAQS.
    After revocation of the 2008 ozone NAAQS, the designations (and the 
classifications associated with those designations) for that NAAQS 
would no longer be in effect. However, the EPA would retain the listing 
of the designated nonattainment areas and their associated 
classifications for the revoked 2008 ozone NAAQS in 40 CFR part 81, for 
the sole purpose of identifying the anti-backsliding requirements that 
may apply to the areas at the time of revocation. Accordingly, such 
references to historical designations for the revoked NAAQS should not 
be viewed as current designations under CAA section 107(d).
    The EPA believes it would be appropriate to revoke, rather than 
retain, the 2008 ozone NAAQS for all purposes because it would ensure 
that only one ozone NAAQS--in this case the more protective 2015 ozone 
NAAQS--would directly apply in an area, rather than having a situation 
in which two standards would apply concurrently. The EPA believes that 
the permanent retention of two standards, differing only in the ozone 
concentrations they allow, could result in unnecessarily complex 
implementation procedures \33\ and is not necessary to provide for 
timely attainment of the more stringent NAAQS. The EPA's reason for 
establishing the new standards of 0.070 ppm as requisite to protect 
public health and welfare was its conclusion that the old standard of 
0.075 ppm was not adequate. Revoking (with appropriate anti-backsliding 
measures) rather than retaining the 2008 ozone NAAQS would facilitate a 
more seamless transition to demonstrating compliance with the more 
health and welfare protective 2015 ozone NAAQS, and would ensure an 
efficient use of state and local resources in working toward attainment 
of that standard. Moreover, we believe that by requiring adequate anti-
backsliding measures we will ensure continued momentum in air agencies' 
efforts toward achieving clean air.
---------------------------------------------------------------------------

    \33\ For example, if an area's boundaries for two ozone NAAQS 
differ from one another the same test of conformity cannot be used 
for both ozone NAAQS (see 77 FR 30168; May 21, 2012).
---------------------------------------------------------------------------

    The D.C. Circuit held that the EPA had authority to revoke the one-
hour NAAQS so long as it introduced adequate anti-backsliding measures. 
South Coast Air Quality Mgmt. Dist. v. EPA, 472 F.3d 882, 899 (D.C. 
Cir. 2006). The EPA is proposing to follow the same approach here as 
was upheld by the D.C. Circuit by requiring adequate anti-backsliding 
measures, as discussed in this section of the preamble.
    b. Option 2: Revoke the 2008 ozone NAAQS for all purposes in an 
area only when designated attainment for that NAAQS, no sooner than 1 
year after the effective date of the designations for the 2015 ozone 
NAAQS. Under this option, the EPA would not revoke the 2008 ozone NAAQS 
in any area that is designated nonattainment for that NAAQS. For areas 
designated attainment or unclassifiable for the 2008

[[Page 81287]]

NAAQS on the effective date of designations for the 2015 ozone NAAQS, 
the 2008 ozone NAAQS would be revoked 1 year after the effective date 
of the 2015 NAAQS designation for that area. For nonattainment areas 
that are subsequently redesignated attainment (maintenance) for the 
2008 ozone NAAQS, the 2008 ozone NAAQS would be revoked upon 
designation, but in no case sooner than 1 year after the effective date 
of the designation for the 2015 ozone NAAQ for the area. This proposed 
approach follows the approach established in revocation of the 1997 
primary annual particulate matter (PM2.5) NAAQS (see 81 FR 
58142, August 24, 2016). This option is also consistent with the 
approach established for the transition from the prior lead and sulfur 
dioxide (SO2) NAAQS to the current lead and SO2 
NAAQS (see 73 FR 67043, November 12, 2008; and 75 FR 35581, June 22, 
2010, respectively).
    Under this proposed approach, areas that are designated 
nonattainment for the 2008 ozone NAAQS at the time initial area 
designations are completed for the 2015 NAAQS would be required to 
continue to meet all applicable implementation requirements for the 
2008 NAAQS in those areas, and would continue to seek redesignation to 
attainment for the 2008 ozone NAAQS when the areas meet the conditions 
necessary for redesignation. While such an area remains designated 
nonattainment for the 2008 ozone NAAQS, transportation and general 
conformity would continue to apply and the EPA would continue to 
reclassify areas as provided in CAA section 181(b)(2). Further, the 
designations for the 2008 ozone NAAQS would no longer be in effect in 
areas where the NAAQS has been revoked, and the sole designations that 
would remain in effect would be those for the 2015 ozone NAAQS. 
Transportation and general conformity requirements for the 2008 ozone 
NAAQS would no longer apply in the areas where that NAAQS has been 
revoked.
    The EPA notes that under proposed option 2, it is unnecessary to 
propose a specific set of additional anti-backsliding requirements for 
the 2008 ozone NAAQS, since option 2 would only revoke this NAAQS in 
areas initially designated or redesignated attainment for the 2008 
NAAQS. Special additional anti-backsliding requirements are not 
necessary for areas that have attained the 2008 NAAQS. In areas that 
have been redesignated to attainment for the 2008 ozone NAAQS while 
that NAAQS is in effect, states have fulfilled all applicable 
attainment and maintenance plan requirements for that NAAQS, including 
applicable anti-backsliding requirements for the prior revoked 1997 and 
1-hour ozone NAAQS. The area, therefore, is not subject to any specific 
additional anti-backsliding requirements for the revoked 2008 ozone 
NAAQS. These areas are required instead to implement their approved CAA 
section 175A maintenance plan for the 2008 ozone NAAQS and, if 
designated attainment for the 2008 ozone NAAQS implement a Prevention 
of Significant Deterioration (PSD) program for this NAAQS. Revisions to 
the approved maintenance plan for such an area can only be made subject 
to the CAA's provisions in sections 110(l) and 193, which prevent 
changes to SIPs if such changes would interfere with attainment and 
maintenance of the more current 2015 ozone NAAQS.
3. Effective Date of the Revocation of the 2008 Ozone NAAQS
    Under either option 1 or 2 outlined earlier, the EPA is proposing 
to revoke the 2008 ozone NAAQS no sooner than one year after the 
effective date of an area's final designation for the 2015 ozone 
standards.\34\ The proposed timeline for revocation of the standard 
under either option 1 or 2 outlined earlier is intended to ensure that 
there is no period during which conformity does not apply in areas that 
are nonattainment or maintenance for the 2008 ozone NAAQS and that are 
designated nonattainment for the 2015 ozone NAAQS, and that 
nonattainment areas for the 2015 ozone NAAQS do not have to perform 
transportation conformity analyses for both the prior and current ozone 
standards at the same time.\35\ As an example, areas designated 
nonattainment for the first time for the 2015 ozone NAAQS would have a 
1-year grace period before transportation conformity applies for those 
standards. This 1-year grace period before transportation conformity is 
required would apply to all areas designated nonattainment for the 2015 
standards, regardless of their 2008 NAAQS designation status. 
Transportation conformity for the 2008 standards would, therefore, no 
longer apply 1 year following the effective date of the 2015 ozone 
NAAQS designations (i.e., when the 2008 standards are revoked in 
eligible areas). However, transportation conformity obligations for the 
2008 ozone standards would remain applicable during the grace period 
and would not be affected by the designation of areas for the 2015 
NAAQS. Our proposed approach further supports air quality planning in 
allowing areas to be redesignated to attainment or reclassified to a 
higher classification until the 2008 ozone NAAQS is revoked.
---------------------------------------------------------------------------

    \34\ The 2008 Ozone NAAQS SIP Requirements Rule revoked the 1997 
ozone standards upon the effective date of that final rule (April 6, 
2015), which was 30 days after its publication in the Federal 
Register (80 FR 12296; March 6, 2015). The EPA deemed this approach 
appropriate because the final SIP requirements rule was being issued 
more than a year after the effective date of final area designations 
(July 20, 2012) for the 2008 ozone standards (77 FR 30160; May 21, 
2012), an atypical sequence that is not expected to apply in this 
case.
    \35\ The EPA believes that these concerns are relevant for 
either proposed option 1 or option 2, and therefore proposes the 
same timeline for revocation for either option. Under option 2, the 
motivation of ensuring that areas do not have to perform 
transportation conformity analyses for both the prior and current 
ozone standards at the same time would only be relevant for 2015 
ozone NAAQS nonattainment areas that are maintenance areas for the 
2008 ozone NAAQS at the time of the initial revocation. Areas that 
remain designated nonattainment for the 2008 ozone NAAQS at the time 
of the initial revocation are required to continue to make 
transportation conformity determinations until they are redesignated 
to attainment for that NAAQS regardless of their designation status 
for the 2015 ozone NAAQS.
---------------------------------------------------------------------------

    If the 2008 ozone NAAQS are revoked in an area in a manner 
consistent with the EPA's first proposed option, the anti-backsliding 
requirements for those NAAQS would become applicable. The extent of 
continued implementation efforts for revoked standards derives from 
administration of anti-backsliding requirements (if any) for the 
revoked standards. After the 2008 ozone NAAQS is revoked for an area, 
the EPA will no longer take action to reclassify or to redesignate that 
area for that NAAQS. Further, the designations for the 2008 ozone NAAQS 
would be no longer be in effect in such areas, and the sole 
designations that would remain in effect would be those for the 2015 
ozone NAAQS. However, under option 1, the EPA would retain the listing 
of the designated areas and the associated nonattainment 
classifications for the revoked 2008 ozone NAAQS in 40 CFR part 81, for 
the sole purpose of identifying the anti-backsliding requirements that 
may apply to the areas as of the effective date of the revocation. Such 
references to historical designations for the revoked standards would 
not be current designations under CAA section 107(d) and should not be 
viewed as such. If the EPA finalizes the option 2 approach to 
revocation of the 2008 ozone NAAQS, the EPA would continue to 
redesignate areas for the 2008 ozone NAAQS after the initial revocation 
occurs 1 year after the effective date of designations for the 2015 
ozone NAAQS. For any area

[[Page 81288]]

redesignated more than 1 year after the effective date of designations 
for the 2015 ozone NAAQS, the 2008 ozone NAAQS would be revoked on the 
effective date of the redesignation to attainment for the 2008 ozone 
NAAQS.
4. Anti-Backsliding Requirements
    ``Anti-backsliding'' provisions are designed to ensure that for 
existing ozone nonattainment areas that are designated nonattainment 
for the revised and more stringent ozone NAAQS, there is protection 
against degradation of air quality (e.g., the areas do not 
``backslide''), the areas continue to make progress toward attainment 
of the new, more stringent NAAQS, and there is consistency with the 
ozone NAAQS implementation framework outlined in subpart 2 of Part D of 
the CAA.
    Where a NAAQS is relaxed, CAA section 172(e) requires EPA to 
promulgate regulations that impose on areas, which have not attained a 
NAAQS prior to a relaxation, controls that are at least as stringent as 
the controls applicable in nonattainment areas prior to any such 
relaxation. Such controls are often referred to as ``anti-backsliding 
requirements.'' Because the CAA does not speak to what to do where a 
NAAQS is strengthened, the EPA has historically concluded, and proposes 
to do so again here, that it is reasonable to look to the principles 
set forth in CAA section 172 to impose anti-backsliding requirements 
for purposes of transitioning to a more stringent NAAQS. See 69 FR 
23951, 23972 (April 30, 2004); 80 FR 12264, 12297-98 (March 6, 2015). 
The D.C. Circuit has upheld the EPA's authority to revoke a superseded 
NAAQS in its entirety where adequate anti-backsliding measures are 
retained under the principles of CAA section 7502(e). South Coast Air 
Qual. Mgmt Dist. v. EPA, 472 F.3d 882, 899 (D.C. Cir. 2006).
    Under option 1, the EPA is proposing to retain, for purposes of the 
transition from the 2008 to the 2015 ozone NAAQS, the existing approach 
to establishing anti-backsliding requirements. The proposed subpart CC, 
40 CFR 51.1300 et seq., provides the set of anti-backsliding 
requirements that would apply following revocation of the 2008 ozone 
NAAQS along with the use of the latest approved or adequate motor 
vehicle emission budgets for a prior ozone NAAQS (i.e., the 2008, 1997 
or the 1-hour ozone NAAQS) at 40 CFR 93.109(c)(2) as part of 
transportation conformity determinations in nonattainment areas for the 
2015 NAAQS until 2015 ozone motor vehicle emissions budgets are 
available.\36\ For reference, the final 2008 Ozone NAAQS SIP 
Requirements Rule provides an extensive discussion of the EPA's 
approach and rationale for establishing anti-backsliding requirements 
consistent with the first proposed revocation option in this proposal 
(option 1) (80 FR 12296-12308; March 6, 2015). The EPA is proposing a 
second approach (option 2) to revoking the 2008 ozone NAAQS that would 
not require the same extensive set of anti-backsliding requirements. 
This co-proposal and associated anti-backsliding approach are discussed 
previously in this section of the preamble.
---------------------------------------------------------------------------

    \36\ The EPA believes it is unnecessary to propose to include 
the use of existing SIP motor vehicle emissions budgets for 
transportation conformity purposes in the proposed list of 
regulatory anti-backsliding requirements subpart CC, 40 CFR 51.1300 
et seq because EPA's regulations (40 CFR 93.109(c)(2)) already 
require that transportation conformity determinations in 
nonattainment areas for the new ozone NAAQS continue to be based on 
the latest approved or adequate motor vehicle emission budgets for a 
prior ozone NAAQS (i.e., the 2008, 1997 or the 1-hour ozone NAAQS) 
until 2015 ozone budgets are available.
---------------------------------------------------------------------------

    The following sections discuss the applicable anti-backsliding 
requirements and how they apply to areas with various designations and 
classifications for the 2015 standards, the 2008 standards that we are 
proposing to revoke, and the already revoked 1997 and 1-hour ozone 
NAAQS. Our proposed approach for revoking the 2008 ozone NAAQS is 
discussed in Section IV.B of this preamble.
    a. Applicable requirements for anti-backsliding purposes following 
the revocation of the 2008 ozone NAAQS. As discussed in more detail in 
Section IV.B of this preamble, the EPA is proposing and seeking comment 
on two options for revoking the 2008 ozone NAAQS. As explained in that 
section, under proposed option 2, it is unnecessary to propose specific 
new anti-backsliding requirements for the 2008 ozone NAAQS, since 
option 2 would only revoke this NAAQS in attainment areas. Therefore, 
the following section would only apply if EPA were to finalize option 1 
for revocation of the 2008 ozone standard. For purposes of the revoked 
2008 ozone NAAQS if option 1 were to be finalized, the EPA is proposing 
to retain the same set of anti-backsliding requirements that currently 
apply for purposes of the revoked 1997 ozone NAAQS, without revision.
    For the revoked 2008 ozone NAAQS, the potentially applicable 
requirements for an area for anti-backsliding purposes would be 
identical to the requirements currently codified at 40 CFR 51.1100(o). 
These requirements include: (1) RACT; (2) Vehicle I/M programs; (3) 
Major source applicability cut-offs for purposes of RACT; (4) ROP and/
or RFP reductions and associated MCDs; (5) the Clean Fuel Fleet program 
under section 183(c)(4) of the CAA; (6) Clean fuels for boilers under 
section 182(e)(3) of the CAA; (7) Transportation control measures 
during heavy traffic hours as provided under section 182(e)(4) of the 
CAA; (8) Enhanced (ambient) monitoring under section 182(c)(1) of the 
CAA; (9) Transportation controls under section 182(c)(5) of the CAA; 
(10) Vehicle miles traveled provisions under section 182(d)(1)(A) of 
the CAA; (11) NOX requirements under section 182(f) of the 
CAA; (12) Attainment demonstrations; (13) Nonattainment contingency 
measures; (14) Nonattainment NSR major source thresholds and offset 
ratios; (15) CAA section 185 requirements for Severe and Extreme areas 
for failure to attain; (16) RACM; and (17) Contingency measures for 
SIPs invoking section 182(e)(5) of the CAA. The use of the latest 
approved or adequate motor vehicle emission budgets for a prior ozone 
NAAQS (i.e., the 2008, 1997 or the 1-hour ozone NAAQS) as part of 
transportation conformity determinations in nonattainment areas for the 
2015 NAAQS until 2015 ozone motor vehicle emissions budgets are 
available has also been recognized as a ``control'' for purposes of 
defining anti-backsliding requirements. South Coast Air Qual. Mgmt. 
Dist. v. EPA, 489 F.3d at 1248 (clarifying South Coast, 472 F.3d at 
904-05). This requirement is already codified at 40 CFR 93.109(c)(2). 
As discussed in the following section, applicability of individual 
anti-backsliding requirements for an area would depend on its 
designation and classification for all three of the revoked standards.
    b. Transition requirements for nonattainment and attainment areas. 
The EPA is proposing to retain its current approach for applying 
transition requirements to various categories of nonattainment and 
attainment areas. This approach is codified at 40 CFR 51.1105, and we 
are proposing to retain the same approach adopted through the 2008 
Ozone NAAQS SIP Requirements Rule in this rulemaking at 40 CFR 51.1305, 
revised to address the revocation of the 2008 ozone NAAQS in addition 
to the other prior revoked standards.
    Table 4 provides a summary of the four transition categories, and 
the proposed requirements that would apply for each of those 
categories. The

[[Page 81289]]

following sections describe each category in detail.

                                Table 4--2015 Ozone NAAQS Transition Obligations
----------------------------------------------------------------------------------------------------------------
                                      Designation for prior     Proposed NNSR/PSD     Other proposed transition
     Designation for 2015 NAAQS               NAAQS                obligations               obligations
----------------------------------------------------------------------------------------------------------------
1. Attainment......................  Attainment/Maintenance  PSD remains in effect.  --Area remains subject to
                                                                                      existing CAA section 175A
                                                                                      maintenance plan for the
                                                                                      prior ozone NAAQS and
                                                                                      requirements already in
                                                                                      the SIP.
                                                                                     --SIP subject to revision
                                                                                      consistent with CAA
                                                                                      sections 110(l) and 193.
                                                                                     --Existing CAA section 175A
                                                                                      maintenance plan, in
                                                                                      combination with an
                                                                                      approved PSD program,
                                                                                      satisfies maintenance
                                                                                      requirement under CAA
                                                                                      section 110(a)(1).
2. Attainment......................  Nonattainment for 2008  Nonattainment NSR in    --Area remains subject to
                                      ozone NAAQS.            effect until            control measures that were
                                                              revocation of the       included in its adopted
                                                              2008 ozone NAAQS;       SIP to meet nonattainment
                                                              then PSD applies.       requirements.
                                                                                     --Control measures can be
                                                                                      modified in, or removed
                                                                                      from, active SIP only with
                                                                                      a CAA section 110(l)
                                                                                      demonstration and a CAA
                                                                                      section 193 demonstration
                                                                                      if applicable.
                                                                                     --Area's approved PSD
                                                                                      program satisfies CAA
                                                                                      section 110(a)(1)
                                                                                      maintenance provision.
3. Nonattainment...................  Attainment/Maintenance  Nonattainment NSR       --Area remains subject to
                                                              applies based on 2015   existing CAA section 175A
                                                              ozone NAAQS             maintenance plan (if
                                                              classification.         applicable) for the prior
                                                                                      NAAQS and requirements
                                                                                      already in the SIP.
                                                                                     --SIP subject to revision
                                                                                      consistent with CAA
                                                                                      sections 110(l) and 193.
4. Nonattainment...................  Nonattainment for 2008  Nonattainment NSR       --Area subject to all
                                      ozone NAAQS.            applies based on        applicable anti-
                                                              highest applicable      backsliding requirements
                                                              classification.         for 1-hr, 1997 and/or 2008
                                                                                      NAAQS.
                                                                                     --The area is no longer
                                                                                      required to adopt any
                                                                                      outstanding applicable
                                                                                      requirements for 1997 and/
                                                                                      or 2008 standards when the
                                                                                      area is redesignated to
                                                                                      attainment for the 2015
                                                                                      ozone NAAQS, or for the
                                                                                      revoked 1-hour, 1997 or
                                                                                      2008 NAAQS when the EPA
                                                                                      approves a redesignation
                                                                                      substitute.
----------------------------------------------------------------------------------------------------------------

    i. Requirements for areas designated attainment for the 2015 ozone 
NAAQS and maintenance for the 2008 ozone NAAQS. For this category, the 
EPA is proposing that for areas designated attainment for the 2015 
ozone NAAQS and maintenance for the 2008 ozone NAAQS, the area's 
approved CAA section 175A maintenance plan for the revoked ozone NAAQS, 
in combination with an approved PSD program, satisfies both its 
obligations for maintenance under CAA section 110(a)(1) for the 2015 
ozone NAAQS and its obligation to submit a second approvable 
maintenance plan under CAA section 175A for the revoked ozone NAAQS. 
This approach recognizes and reflects that such areas have in place an 
ozone air quality management program that has successfully achieved 
initial compliance with the 2015 ozone NAAQS and all previous ozone 
NAAQS. Ongoing compliance with the 2015 ozone NAAQS in such areas will 
be governed by the provisions of the area's approved SIP and the CAA's 
general air quality management requirements in sections 107, 110 and 
182. Any future revisions to the SIP would be subject to the general 
``interference'' provisions of CAA section 110(l) and, if applicable, 
the section 193 savings clause.\37\ Should the area subsequently 
violate the 2015 ozone NAAQS, the contingency measures in the approved 
maintenance plan would be triggered and the area may become subject to 
a SIP call (under CAA section 110(k)(5)) or redesignation to 
nonattainment (under CAA section 107(d)(3)).
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    \37\ Section 110(l) of the CAA indicates that EPA cannot approve 
a SIP revision if the revision would interfere with any applicable 
requirement concerning attainment and RFP, or any other applicable 
requirement of the CAA. Section 193 of the CAA prohibits the 
modification of any rule adopted before November 15, 1990 in areas 
designated as nonattainment for an air pollutant unless the 
modification insures equivalent or greater emission reductions of 
the relevant pollutant.
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    ii. Areas designated attainment for the 2015 ozone NAAQS and 
nonattainment for the 2008 ozone NAAQS. For this category, the EPA is 
proposing that for areas designated attainment for the 2015 ozone NAAQS 
and nonattainment for the 2008 ozone NAAQS, air agencies are relieved 
of adopting any outstanding applicable requirements for the revoked 
standards as of the effective date of the revocation; in other words, 
these areas would not be subject to anti-backsliding requirements under 
the principles of CAA section 172(e). We also propose that PSD SIPs for 
these areas, once approved by the EPA, satisfy the obligation to submit 
an approvable maintenance plan for the 2015 ozone NAAQS under CAA 
section 110(a)(1).
    Areas designated attainment for the 2015 ozone NAAQS and 
nonattainment for the 2008 ozone NAAQS have already attained the most 
stringent existing standard, notwithstanding their existing designation 
as nonattainment for the 2008 NAAQS. Because it is mathematically 
impossible to attain the 2015 NAAQS without having first attained the 
2008 NAAQS (i.e., 0.070 ppm is necessarily less than 0.075 ppm), EPA 
considers these areas to have attained the 2008 NAAQS at the time of 
revocation of that standard. These areas, thus, have implemented an air 
quality management program that, in combination with federal measures 
and emissions controls in upwind areas, has produced sufficient 
emissions reductions to achieve air quality that has both attained the 
prior ozone

[[Page 81290]]

NAAQS and resulted in an attainment designation for the more protective 
2015 ozone NAAQS. In this case, EPA proposes that an air agency would 
not be obligated to implement the applicable anti-backsliding 
requirements set forth in 51.1300(p) and 93.109(c)(2) at the time the 
2008 NAAQS is revoked in these areas. Because CAA section 172(e) only 
speaks to creation of regulatory anti-backsliding requirements for 
``areas which have not attained th[e] standard as of the date of 
[revocation],'' the EPA believes it is appropriate to not require the 
regulatory anti-backsliding requirements listed in 40 CFR 51.1300(p) 
and 40 CFR 93.109(c)(2) in these areas which have attained the 2008 
standard as of the date that standard is revoked (by virtue of an 
attainment designation for a more stringent standard). These areas 
would remain subject to the prior emissions control requirements 
(including contingency measures) already approved into the SIP. The 
prior nonattainment area control requirements already approved into the 
SIP can be revised upon a showing that such revision complies with CAA 
sections 110(l) and 193.
    Given the succession of NAAQS of increasing stringency that has 
occurred, the EPA believes that the burden of developing a separate 
approvable 110(a)(1) maintenance plan for the 2015 ozone NAAQS would 
outweigh any compensating benefit for an area that is already attaining 
that NAAQS and implementing, where applicable, any prior nonattainment 
requirements that are already incorporated into the SIP and have been 
sufficient to bring the area into attainment of both the prior and 2015 
standards. Ongoing compliance with the 2015 ozone NAAQS in such areas 
will be governed by the provisions of the area's approved SIP and the 
CAA's general air quality management requirements in sections 107, 110 
and 182. Should the area subsequently violate the 2015 ozone NAAQS, it 
may become subject to a SIP call (under CAA section 110(k)(5)) or 
redesignation to nonattainment (under CAA section 107(d)(3)).
    iii. Areas designated nonattainment for the 2015 ozone NAAQS and 
maintenance for the 2008 ozone NAAQS. For this category, the EPA is 
proposing that an area's approved CAA section 175A maintenance plan for 
the 2008 ozone NAAQS in combination with nonattainment obligations 
under the 2015 ozone NAAQS would satisfy the obligation to submit a 
second approvable maintenance plan under CAA section 175A for the 
revoked 2008 ozone NAAQS. Areas in this category would already be 
subject to the provisions of an approved CAA section 175A maintenance 
plan for the revoked 2008 ozone NAAQS and would have been redesignated 
to attainment for the revoked 2008 ozone NAAQS. The EPA's approval of 
the redesignation request and of the CAA section 175A maintenance plan 
for the 2008 ozone NAAQS would require the EPA to determine not only 
that all applicable requirements for the 2008 ozone NAAQS have been 
met, but also that all applicable anti-backsliding measures for the 
1997 and 1-hour standards have been adopted and approved into the SIP. 
No revision to a CAA section 175A maintenance plan for these areas can 
be approved unless it complies with the conditions of CAA sections 
110(l) and 193, which would ensure the revision would not interfere 
with attainment and RFP for the 2015 standards.
    Areas in this category would also be designated nonattainment for 
the more stringent 2015 ozone NAAQS and, therefore, would be subject to 
NNSR and other nonattainment requirements for their classification 
under the more stringent 2015 ozone NAAQS. Thus, the EPA believes that 
there is no useful purpose or justification for a second CAA section 
175A maintenance plan that would apply only to the revoked 2008 ozone 
NAAQS, in light of the nonattainment and eventual maintenance 
requirements that apply for the more protective 2015 ozone NAAQS.
    iv. Areas designated nonattainment for the 2015 ozone NAAQS and 
nonattainment for the 2008 ozone NAAQS. For this category, the EPA is 
proposing that for an area designated nonattainment for the 2015 ozone 
NAAQS and nonattainment for the 2008 NAAQS (as of revocation of the 
standard), an air agency would be obligated to implement the applicable 
anti-backsliding requirements set forth in 40 CFR 51.1300(p) and 40 CFR 
93.109(c)(2) for the revoked 2008 ozone NAAQS. This could include, as 
applicable, anti-backsliding requirements associated with the revoked 
1-hour and 1997 ozone NAAQS if the area was also designated 
nonattainment for one or more of these ozone NAAQS when that NAAQS was 
revoked and the status of the area with respect to those revoked NAAQS 
has not been changed through a redesignation substitute. Nonattainment 
NSR would apply in these areas in accordance with their highest 
nonattainment classification under any ozone standards for which they 
are (or were as of the effective date of the revocation) designated 
nonattainment.\38\ Also, if these areas are classified Severe or 
Extreme as of the effective date of the revocation of a prior standard, 
the fee program requirements of CAA section 185 in relation to that 
prior standard would continue to apply.
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    \38\ In the case of an approved redesignation substitute, an air 
agency seeking to remove NNSR provisions associated with a revoked 
NAAQS from the active portion of the SIP must demonstrate 
consistency with CAA sections 110(l) and 193.
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    v. Application of transition requirements to nonattainment and 
attainment areas. For purposes of determining an area's transition 
requirements, we would first look to the area's initial designation for 
the 2015 ozone NAAQS. We would then determine the area's designation 
and classification status for the 2008 ozone NAAQS as of the effective 
date the 2008 ozone NAAQS is revoked. Finally, where appropriate, we 
would determine whether anti-backsliding requirements for the 1997 and 
1-hour ozone NAAQS apply in the area and, if so, we would determine the 
area's designation and classification status for those standards as of 
the dates they were revoked.\39\
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    \39\ If an area was initially designated attainment for the 2008 
ozone NAAQS or was redesignated to attainment (``Maintenance'') for 
the 2008 ozone NAAQS prior to the date of revocation of the 2008 
NAAQS, then consistent with the position we took in the 2008 rule, 
the area is no longer required to adopt any outstanding applicable 
requirements for the revoked 1997 standard.
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5. Satisfaction of Anti-Backsliding Requirements for an Area
    The EPA is proposing to retain its current approach through which 
an air agency may demonstrate that it is no longer required to adopt 
any additional applicable requirements for an area that have not 
already been approved into the SIP for a revoked ozone NAAQS. The final 
2008 Ozone NAAQS SIP Requirements Rule adopted two acceptable 
procedures that, if followed and approved by the EPA, address anti-
backsliding requirements associated with one or more revoked standards. 
These two procedures--formal redesignation to attainment and 
redesignation substitute--are described later. We are proposing to 
retain these two procedures for purposes of revocation of the 2008 
ozone NAAQS. After one of these procedures has resulted in an approval 
by the EPA, an air agency seeking to revise its SIP to remove anti-
backsliding measures, such as NNSR provisions, from the active portion 
of the SIP must demonstrate consistency with CAA sections 110(l) and 
193 (if applicable). Requirements could then be shifted from the active 
portion of the SIP to the contingency

[[Page 81291]]

measures portion of the SIP (80 FR 12304; March 6, 2015).
    The first of the proposed procedures is formal redesignation of the 
area to attainment for the 2015 ozone NAAQS. For areas subject to anti-
backsliding requirements for the revoked 1997 or 2008 standards, 
approval of a request for redesignation to attainment for the 2015 
ozone NAAQS would signify that the air agency has satisfied its 
obligations to adopt anti-backsliding requirements for the revoked 1997 
or 2008 standards. Once the area is redesignated, the requirement(s) 
for NNSR for the 2015 ozone NAAQS and for any prior ozone NAAQS cease 
to apply, and the air agency may begin implementing the PSD program 
requirements. Nonattainment NSR requirements may be removed from the 
SIP, or may be retained as a maintenance plan contingency measure.\40\ 
This procedure is consistent with the EPA's longstanding interpretation 
of NNSR requirements for areas that are redesignated to attainment.\41\ 
It is important to note that lifting the applicability of NNSR SIP 
provisions in an area does not relieve sources in the area of their 
obligations under previously established permit conditions.
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    \40\ States in the OTR may not use this flexibility because the 
CAA requires all areas of the OTR including attainment areas to 
implement, at a minimum, the NNSR requirements prescribed for 
Moderate areas.
    \41\ See Greenbaum v. EPA, 370 F.3d 527, 534 (6th Cir. 2004) 
(``The EPA argues that the Part D NSR program is inapplicable to 
attainment areas, so that the requirement disappears upon 
redesignation. After redesignation, Part D NSR is replaced by a PSD, 
another permitting program designed to ensure maintenance of the 
NAAQS in attainment areas. . . . The NSR program would not be 
implemented as approved, as NSR programs are only required in 
nonattainment areas.'')
---------------------------------------------------------------------------

    Redesignation to attainment would also terminate any obligations to 
implement CAA section 185 fee programs in a Severe or Extreme area for 
the 2015 or revoked 1997 or 2008 ozone NAAQS pursuant to the express 
terms of CAA section 185. All of the remaining anti-backsliding 
measures that have been approved into the SIP must continue to be 
implemented unless or until the air agency can show that such 
implementation is not necessary for maintenance, consistent with CAA 
sections 110(l) and 193 if applicable.\42\
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    \42\ This showing may be submitted to the EPA at the same time 
as the maintenance plan, and may be approved by the EPA in a single 
action. Subject to this process, anti-backsliding requirements 
contained in the SIP could be shifted to the contingency measures 
portion of a CAA section 175A maintenance plan or, in limited 
circumstances (such as nonattainment NSR), removed from the SIP.
---------------------------------------------------------------------------

    The second of the proposed procedures for satisfying the anti-
backsliding requirements associated with a specific revoked standard is 
referred to as a ``redesignation substitute.'' This redesignation 
substitute showing would serve as a successor to redesignation to 
attainment, for which the area would have been eligible were it not for 
revocation. The showing is based on the CAA's criteria for 
redesignation to attainment (CAA section 107(d)(3)(E)), but differs in 
some important respects. This procedure does not require air agencies 
to go through formal SIP submission procedures to submit a request for 
approval of a redesignation substitute because the action is not a 
redesignation under CAA section 107(d)(3)(E). States would have to 
demonstrate that the area has attained the relevant revoked standard 
and met all of the requirements for redesignation for that standard. An 
area would then no longer be subject to any remaining applicable anti-
backsliding requirements associated with the specific revoked NAAQS, 
including the major source thresholds and offset ratios associated with 
the area's classification under those standards.\43\ The remaining NSR 
requirements would be determined by the highest remaining 
classification to which the area is subject, whether for the 2015 ozone 
NAAQS or another revoked NAAQS for which the EPA had not approved a 
redesignation substitute showing.
---------------------------------------------------------------------------

    \43\ An air agency seeking to remove NNSR provisions associated 
with a revoked NAAQS from the active portion of the SIP must 
demonstrate consistency with CAA sections 110(l) and 193.
---------------------------------------------------------------------------

6. Application of the EPA's Determination of Attainment Regulation 
(``Clean Data Policy'') for Purposes of the Anti-Backsliding 
Requirements
    The EPA is proposing to retain its current approach to implementing 
the Clean Data Policy, under which a determination of attainment 
suspends the obligation to submit certain attainment-related planning 
requirements for the associated NAAQS for an area as long as the area 
continues to attain those standards.\44\ This approach is codified at 
40 CFR 51.1118 for the 2008 ozone NAAQS, and we are proposing to retain 
the same approach for the 2015 ozone NAAQS at 40 CFR 51.1318, without 
revision.
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    \44\ The EPA initially issued the Clean Data Policy in 1995, 
``Reasonable Further Progress, Attainment Demonstration, and Related 
Requirements for Ozone Nonattainment Areas Meeting the Ozone 
National Ambient Air Quality Standard.'' Memorandum from John S. 
Seitz, Director, Office of Air Quality Planning and Standards, May 
10, 1995. For purposes of the 1997 ozone NAAQS, we codified that 
policy at 40 CFR 51.918. This codified policy was upheld by the D.C. 
Circuit in NRDC v. EPA, 571 F.3d 1245 (D.C. 2009).
---------------------------------------------------------------------------

    The planning elements that would be suspended under 40 CFR 51.1318 
are the same as those suspended under existing 40 CFR 51.1118: RFP 
requirements, attainment demonstrations, RACM, contingency measures and 
other state planning requirements related to attainment of the relevant 
standards. For a Severe or Extreme area, a CAA section 185 fee program 
is expressly linked by the statute itself to an attainment plan. 
Therefore, suspension of the obligation to submit the attainment plan 
also necessarily suspends the obligation to submit the fee program 
which is part of the attainment plan (provided that the EPA has not 
already determined that the area failed to attain by its attainment 
deadline and, thus, triggered the obligation to implement a fee 
program). The EPA notes that a determination of attainment would not, 
however, suspend obligations to submit non-planning requirements such 
as NNSR, subpart 2 RACT or emission inventories under CAA section 
182(a)(1).
    Under this proposed approach, the EPA's long-standing Clean Data 
Policy, which has been upheld by the D.C. Circuit and all other courts 
that have considered it, would remain embodied in a regulation 
applicable for the purpose of all existing and prior ozone NAAQS. We 
believe that this approach makes the most sense for implementing the 
2015 ozone NAAQS.
7. Relationship Between Implementation of the 2015 Ozone NAAQS and the 
CAA Title V Permits Program
    The EPA is proposing to retain its current approach for 
implementing the title V permit program for sources in areas designated 
nonattainment for the current ozone NAAQS and subject to anti-
backsliding requirements for a prior ozone NAAQS. The final 2008 Ozone 
NAAQS SIP Requirements Rule adopted an approach under which, following 
revocation of the prior (1997) ozone NAAQS, major source thresholds for 
title V would be the same as the major source thresholds applicable for 
purposes of other requirements such as RACT and NNSR (80 FR 12307; 
March 6, 2015). We are proposing to retain this approach for purposes 
of implementing the 2015 ozone NAAQS, without revision.
    Under this proposed approach, following revocation of the 2008 
ozone NAAQS, major source thresholds for title V would be the same as 
the major

[[Page 81292]]

source \45\ thresholds applicable for purposes of other requirements, 
such as RACT and NNSR. Specifically, the major source threshold 
associated with the more stringent of the area's classification for the 
2015, 2008, 1997 and/or 1-hour ozone NAAQS will be the applicable 
threshold for title V purposes, to the extent that anti-backsliding 
requirements for the 2008, 1997 and/or 1-hour ozone NAAQS apply in the 
area.\46\ The final 2008 Ozone NAAQS SIP Requirements Rule amended the 
definitions of ``major source'' in 40 CFR 70.2 and 71.2 as related to 
application of title V thresholds, and we propose to retain these 
definitions for purposes of the 2015 ozone NAAQS.
---------------------------------------------------------------------------

    \45\ One of the ways a source can become subject to title V is 
as a ``major source.'' See CAA section 502(a); 40 CFR 70.3; 71.3. 
Furthermore, the definition of ``major source'' for purposes of 
title V includes, but is not limited to, a ``major stationary source 
as defined . . . in part D'' of title I. (The EPA notes that sources 
can become subject to title V permitting for other reasons, and 
nothing in this discussion is intended to suggest that changes in an 
area's ozone classification would affect those other provisions of 
title V. Accordingly, sources subject to title V under other 
provisions would remain subject to title V for those independent 
reasons.) See CAA section 501(2)(B) and 502(a); 40 CFR 70.2; 71.2. 
Thus, changes in an area's ozone classification (e.g., from 
``Serious'' to ``Severe'') by changing the emissions threshold for 
being deemed a major source (e.g., from 100 tpy to 50 tpy of a 
relevant pollutant) can result in changes in title V applicability 
for a source.
    \46\ It should be noted that, pursuant to CAA section 503(a), a 
source is subject to a permit program on the later of the date that 
it becomes a major source and the effective date of a permit program 
applicable to the source. Thus, if a permitting authority with an 
approved title V program lacks any authority to permit certain 
sources that are major sources subject to title V as a result of 
ozone precursor emissions and an area classification for ozone that 
has a major source threshold lower than 100 tpy (e.g., ``Serious''), 
then there is no title V permit program ``applicable to the source'' 
and those sources have no obligation to apply for a title V permit 
until after such time as a permit program becomes applicable to 
them. The EPA works with states to ensure that all approved title V 
programs are adequate under the CAA.
---------------------------------------------------------------------------

    As background, the EPA notes that, under CAA section 502, sources 
are required to operate in accordance with the terms of a title V 
permit if, among other things, the source is a major source or the 
source is required to have a permit under part D of title I. Thus, even 
if a source is not a major source for purposes of title V, it is still 
required to obtain a title V permit under part D of title I. We believe 
that maintaining consistency between the NNSR and title V thresholds 
promotes compliance with CAA requirements by providing a simpler 
permitting regime, ensuring that sources subject to major source NNSR 
understand they are also subject to title V, and enabling permitting 
authorities to identify sources that are potentially subject to major 
source NNSR.

C. Requirements for RFP: Milestone Compliance Demonstrations (MCD)

1. Background and Summary of Proposal
    The EPA is proposing to revise its existing RFP provisions for 
purposes of the 2015 ozone NAAQS to address MCDs required under CAA 
section 182(g) for ozone nonattainment areas classified Serious or 
higher. The existing regulatory provisions characterize the emissions 
reductions and time intervals that constitute RFP milestones, but do 
not explicitly address the requirements for demonstrating compliance 
with these milestones. The following sections discuss the challenges of 
MCD implementation for ozone, and a proposed approach that would 
satisfy CAA requirements consistent with milestone demonstrations for 
other regulated pollutants.
2. CAA Requirements for Ozone Milestone Compliance Demonstrations
    CAA section 182(g)(1) requires that states demonstrate whether 
nonattainment areas classified Serious, Severe, or Extreme have 
achieved incremental emission reductions needed to ensure attainment of 
the NAAQS (i.e., RFP) by the applicable attainment date at set time 
intervals (i.e., milestones). The statute establishes an initial 
milestone date of 6 years after November 15, 1990, and at intervals of 
3 years thereafter. These milestones are mirrored in the general RFP 
demonstration requirements of CAA sections 182(c)(2)(B) for Serious 
areas, 182(d) for Severe areas, and 182(e) for Extreme areas. As 
discussed in Section III.G of this preamble, we propose to retain the 
existing general RFP requirements for purposes of the 2015 ozone 
standards.
    As noted previously, the existing ozone implementation regulations 
do not explicitly address the MCDs required under the CAA. 
Specifically, CAA section 182(g)(2) requires that states submit to the 
Administrator a demonstration that an RFP milestone has been met, not 
later than 90 days after the date on which the applicable milestone 
occurs. For purposes of CAA section 182(g), the statute refers to the 
required emissions reduction for the time interval as the applicable 
milestone. Section 182(g)(2) of the CAA states that the form, manner of 
submittal, and contents of the required compliance demonstration shall 
be set by the Administrator, by rule.
    CAA sections 182(g)(3) and (g)(5) establish measures a state shall 
elect to implement if the state fails to submit an MCD by the due date 
or the EPA determines that a milestone was not met. For Serious and 
Severe areas, an air agency shall elect within 90 days of the failure 
or determination to: (1) Have the area reclassified to the next higher 
classification; (2) implement additional measures to meet the next 
milestone per the applicable contingency plan; or (3) adopt an economic 
incentive program as described in CAA section 182(g)(4). For an Extreme 
area, an air agency shall within 9 months of the failure or 
determination submit a SIP revision to implement a CAA section 
182(g)(4) economic incentive program.
3. Proposed Approach for Ozone Milestone Compliance Demonstrations
    The EPA is proposing that an air agency will have the option to 
demonstrate milestone compliance in terms of either: (1) Compliance 
with control measures requirements in an RFP plan that complies with 
the requirements of the CAA (e.g., percent implementation), or (2) 
actual emissions reductions, as demonstrated with periodic emissions 
inventory data required under CAA section 182(a)(3)(A). In considering 
the form and content of an ozone MCD submittal, the EPA referenced the 
parallel statutory requirements for PM2.5, which are also 
addressed in the final implementing regulations for the 
PM2.5 NAAQS.\47\ Similar to ozone requirements, CAA section 
189(c)(1) establishes a 3-year cycle for PM2.5 milestones, 
but differs from ozone in how a milestone may be expressed. For 
PM2.5, the statute requires quantitative milestones that 
demonstrate RFP, whereas for ozone the milestone is expressed as the 
actual emissions reduction increment that demonstrates progress toward 
attainment. For both pollutants, the CAA provides Administrator 
discretion in setting the form and content of the milestone 
demonstration submittal.\48\
---------------------------------------------------------------------------

    \47\ See 81 CFR 58063-64 (August 24, 2016).
    \48\ CAA sections 182(g)(2) and 189(c)(2) share the same basic 
milestone demonstration submittal requirements, i.e., not later than 
90 days after the date on which an applicable milestone occurs, each 
State in which all or part of such area is located shall submit to 
the Administrator a demonstration that the milestone has been met. A 
demonstration shall be submitted in such form and manner, and shall 
contain such information and analysis, as the Administrator shall 
require. For PM2.5, the statute further qualifies that 
the submittal also demonstrate that all measures in the SIP have 
been implemented.
---------------------------------------------------------------------------

    The final implementing regulations for the PM2.5 NAAQS 
require that the quantitative milestones be constructed

[[Page 81293]]

such that they can be tracked, quantified and/or measured adequately in 
order for an air agency to meet its milestone reporting obligations, 
which come due 90 days after a given milestone date. For 
PM2.5, the EPA interprets CAA section 189(c) to allow air 
agencies to identify milestones that are suitable for the specific 
facts and circumstances of the attainment plan for a particular area, 
so long as they provide an objective means to measure RFP.\49\
---------------------------------------------------------------------------

    \49\ In the Addendum to the General Preamble, the EPA suggested 
(for implementation of the PM10 NAAQS) possible metrics 
that ``support and demonstrate how the overall quantitative 
milestones identified for an area may be met,'' such as percent 
implementation of control strategies, percent compliance with 
implemented control measures, and adherence to a compliance 
schedule. This list was not exclusive or exhaustive but reflected 
the EPA's view that the purpose of the quantitative milestone 
requirement is to provide an objective way to determine whether the 
area is making the necessary progress towards attainment by the 
applicable attainment date (59 FR 42016; August 16, 1994).
---------------------------------------------------------------------------

    We are proposing a similar approach for MCDs for the 2015 ozone 
NAAQS. We believe it would be sufficient for purposes of CAA section 
182(g)(2) for an air agency to demonstrate milestone compliance in 
terms of compliance with control measures requirements in the approved 
RFP plan (e.g., percent implementation). The EPA would review each RFP 
plan submission on a case-by-case basis to determine whether the 
milestones contained in the plan are specific enough to provide an 
objective means for evaluating the area's progress toward attainment, 
consistent with the statutory requirements of CAA section 182(g).
    This proposed measure provides a reasonable and feasible means to 
implement the demonstration requirement in CAA section 182(g)(2) 
because it is grounded in SIP provisions that correlate control 
measures and resulting emissions reductions. Conversely, the EPA 
believes it would not typically be feasible for air agencies to 
demonstrate compliance with milestones based on an assessment of actual 
emissions data because such data are not typically expected to be 
timely available. Compiling and analyzing area-wide emissions data can 
be a resource intensive and time consuming process that the EPA expects 
takes many months after the end of an emissions reporting year. In 
fact, the EPA's triennial emissions reporting rules provide no less 
than 12 months for states to report annual emissions after the end of 
the calendar year.\50\ This timing and resource concern is expected to 
be even greater in a case where the MCD year and triennial emissions 
reporting year are not aligned, such that the 90-day MCD submittal 
timeframe would end well before emissions data from that reporting 
process become available. For example, for an area with an RFP baseline 
year of 2016, the first MCD year would be 2022 (6 years after RFP 
baseline year). In this example, the most recent emissions reporting 
year would be 2020, and the following emissions reporting cycle would 
not end until 2023. This asynchronous timing would continue through 
subsequent 3-year MCD cycles after the initial (6-year) MCD submission. 
Our proposed optional approach would allow an air agency to uncouple 
MCD submissions from the triennial cycle for periodic emissions 
inventories, to facilitate compliance with the 90-day MCD submittal 
timeframe under CAA section 182(g)(2), while preserving the option to 
rely on periodic emissions inventory data where the appropriate data 
are obtainable within the 90-day MCD submittal timeframe.
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    \50\ Triennial emissions reporting periods are set by regulation 
in the Air Emissions Reporting Requirements at 40 CFR part 51, 
subpart A. The most recent and upcoming reporting years are 2014, 
2017, 2020, 2023 and 2026, where the reports are due to the EPA by 
December 31 of the calendar year that follows the reporting year. 
The EPA's implementing regulations for the ozone NAAQS provide that 
states may use the most recent triennial report period emissions 
inventory to satisfy the nonattainment area reporting requirements 
of CAA section 182(a)(3)(A). See 40 CFR 51.1115(b).
---------------------------------------------------------------------------

    We invite comment on this proposed approach for MCDs, including 
potential alternatives to reporting actual emissions data as measures 
for demonstrating RFP that air agencies can reasonably assess and 
report within 90 days of each milestone.

D. Requirements for RACT: Deadlines for Submittal and Implementation of 
RACT SIP Revisions

1. Background and Summary of Proposal
    The EPA is proposing to retain its existing general RACT provisions 
(see Section III.H of this preamble), and to add new RACT SIP revision 
submission and implementation deadlines for specific kinds of 
triggering events that occur after initial area designations under a 
revised ozone NAAQS. The existing RACT provisions address submission 
and implementation deadlines for areas (including portions of a state 
located in an OTR) subject to initial designation and existing RACT 
requirements, including measures described in existing CTGs. However, 
existing RACT provisions do not contemplate some RACT SIP revision 
submittal and implementation deadlines triggered by events occurring 
after initial area designations, including area reclassifications and 
the issuance of new CTGs. The following sections address the proposed 
new RACT submittal and implementation deadlines for these post-
designation scenarios.
2. RACT SIP Revision Submittal and Implementation Deadlines for Newly-
Reclassified Areas
    CAA section 182(b)(2) establishes that a state shall submit a 
revision to a SIP to provide for implementation of RACT by 2 years 
after November 15, 1990, and provide for RACT implementation as 
expeditiously as practicable, but no later than May 31, 1995 
(approximately 54 months total). For purposes of the 2008 ozone NAAQS, 
the EPA interpreted this CAA timeframe to require submittal of RACT SIP 
revision no later than 24 months after the effective date of initial 
area designations, and implementation of the RACT SIP revisions no 
later than January 1 of the fifth year after the effective date of 
initial designations. We did not, however, establish regulatory 
schedules for submission and implementation of RACT SIP revisions for 
areas reclassified after initial area designations under an ozone 
NAAQS.\51\ This includes mandatory reclassification to a higher 
classification upon failure to attain (pursuant to CAA section 
181(b)(2)), or voluntary reclassification to a higher classification 
upon an air agency's request (pursuant to CAA section 181(b)(3)).
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    \51\ For purposes of this preamble discussion, 
``reclassification'' is assumed to encompass nonattainment areas 
being reclassified, attainment areas being redesignated as 
nonattainment and assigned an initial Moderate-or-higher 
classification, and new OTR assignments. Similarly, ``RACT SIP 
revision'' is assumed to encompass initial RACT SIPs triggered by an 
initial area classification of--or reclassification to--Moderate or 
higher.
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    To address these reclassification scenarios, we are proposing 
default submission and implementation deadlines for resulting SIP 
revisions. The EPA is proposing that, following a reclassification 
action, RACT SIP revisions be submitted no later than 24 months after 
the effective date of reclassification, or the deadline established by 
the Administrator in the action reclassifying an area. We are proposing 
that the RACT SIP revisions be implemented as expeditiously as 
practicable, but no later than the start of the ozone season attainment 
year associated with the area's new attainment deadline, or January 1 
of the third year after the associated SIP revision submittal deadline, 
whichever is earlier. We are also proposing that the Administrator 
would retain existing

[[Page 81294]]

authority to establish a different implementation deadline in the 
action reclassifying an area. For example, for an area initially 
classified in 2017 as Marginal that is reclassified in 2021 as 
Moderate, the Administrator could require that a RACT SIP revision be 
submitted no later than 1 year after the final reclassification action 
(i.e., 2022). In this case, the RACT SIP revision must then be 
implemented no later than the start of the ozone season attainment year 
(i.e., 2023), unless a different implementation deadline were 
established in the reclassification action. This proposed approach 
would apply to nonattainment area reclassifications and any portion of 
a state newly included in an OTR.
    For the timeline for implementing RACT SIP revisions triggered by 
area reclassifications that occur after initial area designations, we 
propose to establish a deadline relative to the submittal due date for 
associated RACT SIP revisions. The CAA authorizes the Administrator to 
adjust applicable SIP submission deadlines as necessary or appropriate 
to assure consistency among required submissions. Regarding mandatory 
reclassifications pursuant to CAA section 181(b)(2), CAA section 182(i) 
allows the Administrator to adjust applicable deadlines (excluding 
attainment dates), including those for SIP submittals. For voluntary 
reclassifications, CAA section 181(b)(3) does not establish a precise 
timeframe for submitting an attainment plan. Current practice is that 
we establish SIP revision submittal deadlines through the action 
granting an air agency's request for voluntary area reclassification. 
Depending on the timing of the reclassification action, the resulting 
SIP revision submittal deadline might allow adequate lead time for RACT 
implementation, or impinge on the applicable attainment year (i.e., the 
ozone season immediately preceding a nonattainment area's maximum 
attainment date). In the latter case, timely RACT implementation may be 
difficult or infeasible, with an implementation deadline potentially 
approaching or exceeding the reclassified area's new maximum attainment 
date. We still believe it is important to provide a generic 
implementation deadline, in addition to retaining Administrator 
discretion in setting a specific implementation deadline where 
appropriate.
    We are proposing a generic RACT SIP implementation deadline of no 
later than January 1 of the third year after the associated SIP 
revision submittal deadline. This generic implementation deadline would 
apply where the Administrator elects to not establish a specific 
alternate implementation deadline in an area reclassification action. 
The proposed interval between the RACT SIP revision submittal deadline 
and the implementation deadline was developed by drawing a parallel to 
the construct of the overall RACT SIP revision submittal and 
implementation timeframe articulated in section 182(b)(2) of the CAA. 
In the statute, SIP revisions for sources of VOCs were required by 2 
years after November 15, 1990, and were required to provide for RACT 
implementation as expeditiously as practicable, but no later than the 
start of the ozone season that is the third year after the SIP revision 
deadline (i.e., May 31, 1995, approximately 54 months total).
    We invite comment on the proposed submission and implementation 
deadlines for SIP revisions resulting from reclassification actions.
3. RACT SIP Revision Submittal and Implementation Deadlines Associated 
With New Control Techniques Guidelines
    The CAA is silent regarding the schedule for implementation of RACT 
SIP revisions triggered by new CTGs. When new CTGs are issued, these 
RACT SIP revisions would be applicable to areas classified Moderate or 
higher, and any portion of a state located in an OTR. For CTGs in 
effect at the time of initial designations for a revised NAAQS, the EPA 
has interpreted the CAA provisions to require implementation of related 
RACT SIP revisions as expeditiously as practicable, but no later than 
January 1 of the fifth year after the effective date of initial 
designations for the revised NAAQS (80 FR 12279; March 6, 2015). For 
new CTGs issued after initial area designations, we considered several 
approaches for establishing deadlines for submitting and implementing 
RACT SIP revisions.
    Under the first approach, we are proposing a RACT SIP submission 
deadline of no later than 24 months after the effective date of the 
action issuing the CTG, or the deadline established by the 
Administrator in the action issuing the CTG. We are proposing that the 
RACT SIP revisions be implemented no later than January 1 of the third 
year after the associated SIP revision submittal deadline. This 
deadline is based on the same rationale and approach used for our 
proposed generic implementation deadline for RACT SIP revisions 
triggered by reclassification actions, discussed in the preceding 
section. We are requesting comment on the appropriate implementation 
deadline, and propose that it should in no case exceed January 1 of the 
third year after the SIP revision submittal deadline.
    Under the second approach, we would also articulate in the general 
RACT provisions the Administrator's authority to establish an alternate 
to the generic deadline for implementing RACT SIP revisions in the 
action issuing a new CTG. Under this option, setting a RACT SIP 
revision implementation deadline in a CTG action would allow the 
Administrator to tailor the implementation timeframe to the particular 
technical considerations and attainment objectives associated with the 
sources subject to the CTG.
    We are proposing this second combined approach that would establish 
a generic RACT implementation deadline for SIP revisions resulting from 
new CTGs, while also articulating the Administrator's authority to set 
a different implementation deadline in the action issuing a new CTG. 
This proposed approach would apply to covered sources nonattainment 
areas and portions of a state located in an OTR subject to new RACT SIP 
obligations. Under this proposed approach, RACT SIP revisions must be 
submitted no later than 24 months after the effective date of 
reclassification, or the deadline established by the Administrator in 
the action issuing a new CTG. We are proposing that RACT SIP revisions 
be implemented as expeditiously as practicable, but no later than 
January 1 of the third year after the associated SIP revision submittal 
deadline. This generic implementation deadline would apply where the 
Administrator elects to not establish a specific RACT implementation 
deadline for an individual new CTG. Note that the CAA already requires 
that RACT SIP revisions triggered by a new CTG must be submitted within 
the period specified by the Administrator in the action issuing the new 
CTG. We invite comment on the proposed submission and implementation 
deadlines for SIP revisions resulting from new CTGs.
    As discussed in Section III.H of this preamble, the EPA is 
proposing to otherwise adopt all existing RACT requirements for 
purposes of the 2015 ozone NAAQS, based on the current rationale and 
approach articulated in the final 2008 Ozone NAAQS SIP Requirements 
Rule.

[[Page 81295]]

E. Requirements for RACM: Consideration of Sources of Intrastate 
Transport of Pollution

1. Background and Summary of Proposal
    The EPA is proposing to retain its existing general RACM provisions 
(see Section III.H of this preamble), and to clarify in the rule that, 
in addition to sources located in an ozone nonattainment area, air 
agencies must also consider the impacts of emissions from sources 
outside an ozone nonattainment area (but within a state's boundaries), 
and must require other measures for emissions reductions from these 
intrastate sources if needed to attain the ozone NAAQS by the 
applicable attainment date. This proposed rule provision is consistent 
with SIP elements required under the CAA, as well as existing EPA 
policy articulated in previous NAAQS implementation rulemakings.
2. Applicability of CAA Requirements and Existing EPA Policy
    CAA section 172(c)(6) requires that SIP provisions include 
enforceable emission limitations and other control measures, means or 
techniques as may be necessary to attain a standard by the applicable 
attainment date. The EPA interprets this provision to include 
``additional reasonable measures,'' which are those measures and 
technologies that can be applied to any emission source within an air 
agency's jurisdiction, including those outside of a nonattainment area. 
Upwind sources within a state may have a significant impact on air 
quality in a nonattainment area, and failure to consider and require, 
as appropriate, reasonable control measures for these sources may 
preclude the expeditious attainment of a NAAQS in the area. Though not 
directly a part of RACM, the EPA has addressed this ``other control 
measures'' provision in the preamble discussions for previous NAAQS 
implementation rulemakings,\52\ and proposes to codify this 
interpretation in the ozone implementation rules.
---------------------------------------------------------------------------

    \52\ See the Phase 2 final rule to implement the 8-hour ozone 
NAAQS (70 FR 71623; November 29, 2005) and the final rule to 
implement the PM2.5 NAAQS (81 FR 58035; August 24, 2016).
---------------------------------------------------------------------------

3. Proposed Requirement for RACM, Other Control Measures and Sources of 
Intrastate Transport of Pollution
    The EPA is proposing that, for each nonattainment area required to 
submit an attainment demonstration (see Section III.F of this 
preamble), an air agency shall submit with the attainment demonstration 
a SIP revision demonstrating that it has adopted all RACM necessary to 
demonstrate attainment as expeditiously as practicable and to meet any 
RFP requirements. This SIP revision shall include, as applicable, other 
control measures on sources of emissions of ozone precursors located 
outside the nonattainment area or portion thereof, located within the 
state if doing so is necessary to provide for attainment of the 
applicable ozone NAAQS within the area by the applicable attainment 
date.
    We invite comment on the proposed inclusion of this SIP revision 
requirement for RACM and other control measures in the ozone 
implementation rule provisions. As discussed in Section III.H of this 
preamble, the EPA is proposing to otherwise adopt all existing RACM 
requirements for purposes of the 2015 ozone NAAQS, based on the current 
rationale and approach articulated in the final 2008 Ozone NAAQS SIP 
Requirements Rule.

F. Nonattainment NSR Offset Requirement: Interprecursor Trading for 
Ozone Offsets

1. Background
    In 2015, the EPA took final action in the 2008 ozone SRR to amend 
the regulatory text in 40 CFR 51.165 and part 51 Appendix S to allow 
air agencies to permit IPT for ozone as part of their NNSR 
programs.\53\ See existing 40 CFR 51.165(a)(11)(i) and part 51 Appendix 
S section IV.G.5(i). These ozone IPT provisions allow any new or 
modified major stationary source locating in an ozone nonattainment 
area to satisfy the NNSR emissions offset requirements for ozone with 
emissions reductions of VOC or NOX interchangeably.
---------------------------------------------------------------------------

    \53\ The term interprecursor trading (IPT) is being used in this 
preamble to describe the EPA's policy supporting the use of 
emissions reductions of precursors of a pollutant (NOX 
and VOC for ozone) to be used interchangeably as emissions offsets 
under the NNSR program. The EPA recognizes that other terms, 
including interpollutant trading, interpollutant offsetting, and 
interprecursor offset substitution, have also been used in the past. 
The EPA intends to use ``IPT'' moving forward to promote consistency 
in this preamble.
---------------------------------------------------------------------------

    On May 5, 2015, a coalition of environmental and health advocate 
groups \54\ filed an administrative petition for reconsideration 
raising two specific challenges to the EPA's codified IPT policy. 
Petitioners alleged that the EPA unlawfully failed to provide for 
adequate public comment on the ozone IPT provisions that we finalized 
and, in addition, that the CAA specifically prohibits ozone IPT in the 
NNSR context. The EPA granted the petition for reconsideration on 
November 5, 2015, in order to allow for public comment on those 
provisions.
---------------------------------------------------------------------------

    \54\ Earthjustice filed the petition on behalf of Sierra Club, 
Conservation Law Foundation, Downwinders at Risk and the Physicians 
for Social Responsibility--Los Angeles.
---------------------------------------------------------------------------

    This action, in response to the petition for reconsideration, 
proposes and requests comment on ozone IPT provisions for the NNSR 
offset requirement, as described in Sections IV.F.2 and 4 of this 
preamble. Under these provisions, IPT cannot be used to meet the NNSR 
offset requirement unless the precursor substitution is technically 
supported. For air agencies implementing an EPA-approved NNSR program, 
these provisions must be approved in the air agency's plan addressing 
NNSR requirements for ozone. In addition, as explained in Section 
IV.F.5 of this preamble, the EPA is including a Technical Guidance 
Document (TGD) (in the Docket to this rulemaking) to assist air 
agencies and major stationary sources of ozone in the development of 
ozone IPT ratios tailored to particular ozone nonattainment areas. The 
EPA also requests comment on the process and framework described in 
this TGD to establish IPT ratios.
2. Proposed IPT Provisions for Ozone Offsets
    The EPA proposes to reaffirm its longstanding policy that air 
agencies may allow major stationary sources to use ozone IPT to satisfy 
the NNSR offset requirements in ozone nonattainment areas. In addition, 
the EPA is proposing criteria for developing and implementing ozone IPT 
programs that will be applicable in particular ozone nonattainment 
areas. The proposed ozone IPT provisions would replace the existing 
provisions contained in the NNSR regulations at 40 CFR 51.165 and 
Appendix S. In addition, the EPA proposes that these ozone IPT 
provisions would supersede any previous ozone IPT policy articulated in 
EPA guidance.\55\
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    \55\ The EPA's prior guidance concerning the use of IPT to 
satisfy the NNSR requirements for emissions offsets was contained in 
a 2001 EPA document titled ``Improving Air Quality with Economic 
Incentive Programs'' (January 2001). The EPA's policy on IPT for 
ozone, when finalized through this rulemaking, will supersede the 
information contained in that earlier document specifically with 
respect to IPT.
---------------------------------------------------------------------------

    In proposing new ozone IPT provisions, it is important to note that 
the EPA is not proposing to change or seek comment on any existing or 
traditional NNSR emissions offsets requirements contained in the NNSR 
regulations at 40 CFR 51.165 and part 51 Appendix S. Existing NNSR 
emissions

[[Page 81296]]

offset requirements are based largely on Part D of title I of the CAA's 
nonattainment requirements. These existing requirements include the 
statutory offset ratios applicable in specific ozone nonattainment 
areas (based on an area's classification for ozone), geographic 
restrictions as to where creditable emissions reductions may be 
obtained, and other criteria concerning the creditability of emissions 
reductions to be used as offsets.
    A key component of an ozone IPT program for any ozone nonattainment 
area is an IPT ratio.\56\ An IPT ratio is intended to ensure that the 
substitution of one ozone precursor for another in an offset 
transaction, substantiated by modeling or other technical 
demonstration, provides an equivalent or greater air quality benefit 
for ozone concentrations in the ozone nonattainment area. The EPA is 
proposing that air agencies submit to the EPA as part of a plan that 
must be approved by the Administrator: (1) Their ozone IPT provisions, 
including the default IPT ratio(s) where applicable; (2) a description 
of the air quality model(s) that have been used to develop any default 
ratio(s); and (3) an accompanying modeling demonstration that such 
ratio(s) provide an equivalent or greater air quality benefit for ozone 
concentrations in the ozone nonattainment area. The EPA recommends that 
each air agency implementing an ozone IPT program consult with the 
appropriate EPA Regional office as the air agency develops a modeling 
protocol to establish IPT ratios for a particular nonattainment area. 
The EPA seeks comment on the proposed contents of the plan submission 
and the approach for establishing area-specific default IPT ratios.
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    \56\ The IPT ratio is separate and distinct from the statutory 
ratios contained in the CAA and associated with area classifications 
for ozone nonattainment areas. Both ratios must be applied in 
determining the appropriate emissions offset that must be applied 
for a particular offset transaction.
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    The EPA proposes to provide flexibility for air agencies to 
incorporate IPT ratios into their IPT programs for ozone nonattainment 
areas.\57\ As stated in the 2008 PM2.5 NSR rulemaking, the 
EPA believes the flexibility provided by this policy allows air 
agencies and sources to take into account the role that ozone 
precursors play in the formation of ground-level ozone in specific 
ozone nonattainment areas due to the specific terrain, local and 
regional source emissions mixture, and meteorological conditions that 
exist in each area, and to select the most cost-effective manner to 
obtain the offsets necessary to ensure that air quality improves. This 
flexibility will also be beneficial where offsets for one particular 
precursor are scarce in a particular area. The goal of the CAA is to 
have air quality that is healthy, i.e., meeting the NAAQS, and there is 
a strong principle in the CAA that air agencies have discretion to 
choose from a range of options in designing plans to meet that goal, 
which may include the choice to use the most cost-effective measures to 
get there.
---------------------------------------------------------------------------

    \57\ For a discussion of proposed options for air agencies to 
implement their ozone IPT provision, see Section IV.F.4 of this 
preamble.
---------------------------------------------------------------------------

    When the EPA published its NNSR implementation rules for 
PM2.5 in 2008, we indicated that, while the new 
implementation rules allowed for air agencies to adopt EPA-approved IPT 
programs to satisfy the NNSR offset requirements for PM2.5, 
such trading for netting purposes was disallowed. See 73 FR 28340 (May 
16, 2008). Consistent with that policy, the EPA intends that IPT not be 
allowed for purposes of netting under the NNSR program.
    Use of ozone IPT is not permissible where an air agency chooses to 
include emissions offsets from NNSR air permitting in their initial 15 
percent RFP (ROP) plan for those Moderate or higher ozone nonattainment 
areas that are satisfying this ROP requirement for the first time under 
CAA section 182(b)(1)(A)(i). The EPA believes that this restriction on 
the use of IPT is necessitated by the CAA, which provides that this 
initial RFP (ROP) plan requirement must be satisfied exclusively by 
reductions in VOC emissions.\58\ We seek comment on this restriction on 
ozone IPT.
---------------------------------------------------------------------------

    \58\ See CAA Section 182(b)(1)(a)(1)(i), the final 2008 ozone 
SRR (80 FR 12269, March 6, 2015) and section III.G of this preamble.
---------------------------------------------------------------------------

3. Authority To Establish Ozone NNSR IPT
    The EPA previously authorized IPT to satisfy the NNSR offset 
requirement for PM2.5 \59\ in its NNSR regulations pursuant 
to the CAA. The EPA continues to believe that the CAA accommodates the 
use of technically supported IPT to satisfy the NNSR offset 
requirement.\60\ Section 173(c)(1) of the CAA states that the NNSR 
offset requirement shall ``assure that the total tonnage of increased 
emissions of the air pollutant from the new or modified source shall be 
offset by an equal or greater reduction, as applicable, in the actual 
emissions of such air pollutant from the same or other sources in the 
area.'' Section 302(g) of the CAA defines ``air pollutant'' to include 
``. . . any precursors to the formation of any air pollutant, to the 
extent the Administrator has identified such precursor or precursors 
for the particular purpose for which the term `air pollutant' is 
used.'' (Emphasis added).
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    \59\ The EPA notes that this proposal concerns only IPT for 
ozone. Accordingly, this action does not affect the existing 
requirements concerning PM2.5 IPT.
    \60\ See 73 FR 28321, 28340 and 28347 (May 16, 2008).
---------------------------------------------------------------------------

    The EPA's NNSR regulations identify both NOX and VOC as 
precursors for ozone, and, as such, NOX and VOC are both 
regulated under NNSR as part of the regulation of ozone (See 40 CFR 
51.165(a)(xxxvii)(C)(1)). Thus, when applied to ozone, the term ``air 
pollutant'' in section 173 of the Act may be read to describe both 
NOX and VOC, which are precursors for the pollutant ozone. 
The EPA, therefore, reads the Act to allow the total annual tonnage of 
emissions of one ozone precursor to be offset by reductions in total 
annual emissions of another ozone precursor (in units of tpy) pursuant 
to an IPT ratio that shows the reductions will have an equivalent or 
greater air quality benefit. This cannot replace or supersede the 
statutory ratio for the applicable area classification, which must be 
considered in developing the IPT ratio.
    Emissions of NOX and VOC are not considered 
interchangeable for all aspects of ozone control. For example, in 
certain situations for RFP purposes, the CAA NNSR requirements for 
ozone in the CAA expressly require reductions in VOC emissions. 
However, in many NNSR permitting situations, with an appropriate 
technical demonstration, it is possible to establish ratios for using 
NOX decreases to offset VOC increases, or vice versa, that 
result in an equivalent or greater air quality benefit for ozone 
concentrations in the ozone nonattainment area.
4. Proposed Implementation of Ozone NNSR IPT Provisions
    The EPA recognizes that ozone IPT can be implemented in several 
ways, with the primary variable being the way in which the IPT ratio is 
established and applied. The EPA proposes that air agencies be allowed 
to choose any of the options presented later, including a combination 
if so desired, as a feature of their EPA-approved NNSR programs. 
However, as explained in Section IV.F.4.c of this preamble, we believe 
that for implementing ozone IPT in NNSR permits issued pursuant to 
Appendix S, an air agency will be limited to the use of case-by-case 
IPT ratios. Accordingly, with the goal of providing flexibility to air 
agencies/

[[Page 81297]]

sources, the EPA is proposing and seeking comment on the following 
implementation options:
    a. EPA approval of case-by-case ozone IPT ratios. Under a case-by-
case ozone IPT ratio option, air agencies would generally require each 
permit applicant who wishes to use ozone IPT to satisfy the NNSR 
emissions offset requirement to calculate the ozone IPT ratio that 
would be used to determine the amount of the required emissions 
reduction for each proposed project. The EPA believes that this option 
would be desirable for air agencies that anticipate few requests for 
ozone IPT and do not want to expend the resources needed to establish 
an up-front area-specific default ratio as described in Section 
IV.F.4.b of this preamble. The EPA is proposing that, in choosing this 
option, the air agency must include for the EPA's approval a plan 
submission addressing NNSR program provisions that explicitly authorize 
case-by-case IPT ratios for a particular ozone nonattainment area(s). 
Such plan submission must include the procedures by which permit 
applicants may implement ozone IPT in satisfying the NNSR emissions 
offset requirement, including a description of the model(s) that will 
be used, and the calculation of the IPT ratio with a demonstration that 
such IPT ratio provides an equivalent or greater air quality benefit 
for ozone concentrations in the ozone nonattainment area. The EPA is 
also proposing that the air agency's ozone IPT provision must provide 
that any ozone IPT ratio that an applicant proposes for an individual 
permit must be approved by both the reviewing authority and the EPA.
    b. EPA approval of area-specific default ozone IPT ratio. Under the 
area-specific default ozone IPT option, an air agency would adopt in 
its plan addressing NNSR requirements for ozone an area-specific 
default IPT ratio to be used for all applicable NNSR permits issued in 
a particular ozone nonattainment area. This option would require that a 
description of the model(s) used, along with the calculated default 
ratio and the technical demonstration substantiating the equivalent or 
greater ozone benefit in that nonattainment area, be included in a plan 
submission for EPA approval. A default ratio that has become part of an 
approved plan and has undergone public comment during the plan approval 
process would not require further EPA approval, or be subject to 
additional public comment, each time it is utilized by individual 
permit applicants.
    c. Limitations for implementing ozone IPT under Appendix S. In the 
specific case where an air agency issues permits pursuant to the 
interim NNSR requirements under Appendix S, the EPA believes that the 
air agency's only discretionary option for implementing ozone IPT is 
the case-by-case ratio option described in Section IV.F.4.a of this 
preamble. The NNSR requirements under Appendix S generally apply to 
permits issued in ozone nonattainment areas before the air agency 
receives approval of its plan including an NNSR program. Thus, such air 
agencies would not have the opportunity to include in their plan an IPT 
provision that includes an area-specific default ozone IPT ratio. 
Accordingly, the EPA is proposing regulatory language in the ozone IPT 
provisions of Appendix S to include the requirement that each permit 
applicant seeking to satisfy the offset requirement through IPT must 
identify and substantiate a case-by-case ratio and provide the 
necessary justification demonstrating an equivalent or greater ozone 
benefit in the nonattainment area. The EPA is proposing in Appendix S 
that such ratio must be approved by both the reviewing authority and 
the EPA. See proposed section IV.G.5 of Appendix S in 40 CFR part 51.
    d. Other implementation considerations. The EPA is also proposing 
for consideration a requirement that the air agency periodically review 
an area-specific default ratio that is included in its EPA-approved 
ozone IPT program to ensure the default ratio continues to be valid for 
the area. The air agency would need to submit new modeling to confirm 
that the default ratio is still appropriate. The EPA proposes that such 
periodic evaluation occur at least every 3 years from the air agency's 
prior plan submission including a default area-specific IPT ratio. The 
EPA believes the 3-year period is reasonable, since it coincides with 
RFP milestone dates and periodic area-specific emissions inventory 
submission deadlines. The EPA seeks comment on the need to require that 
an EPA-approved IPT program include periodic program evaluations by the 
air agency and the appropriate frequency of such evaluations.
    As explained earlier, the EPA believes that it is reasonable for 
air agencies to have the option of implementing either a case-by-case 
ozone IPT ratio or an area-specific default IPT ratio, depending on the 
needs and capabilities of the individual air agencies. The EPA also 
believes that air agencies having EPA-approved NNSR programs should 
have the option of implementing a combination of the two proposed 
options. This would enable an air agency to develop an area-specific 
default IPT ratio, but, at the same time, allow an individual permit 
applicant to propose an alternative case-specific IPT ratio (if it can 
demonstrate to the satisfaction of both the reviewing authority and the 
EPA that such alternative ratio is appropriate for the proposed 
offsetting transaction for a specific permit application).
    Finally, IPT programs are discretionary on the part of air agencies 
and are not required SIP revisions. Therefore, air agencies would not 
be required to submit a regulatory provision consistent with the 
proposed IPT provision at 40 CFR 51.165(a)(11)(i) within the 36-month 
timeframe set forth in 40 CFR 51.1314 for NSR requirements for the 
revised ozone NAAQS. Air agencies would be permitted to submit an IPT 
plan revision to the EPA for approval within the 36-month timeframe or 
at any later date that the air agencies deems to be appropriate.
5. Proposed Technical Guidance Document for Developing Ozone IPT Ratios
    As mentioned earlier in the preamble, the EPA is including a TGD in 
the docket for this rulemaking. The purpose of the proposed TGD is to 
provide air agencies with guidance on a technical approach to estimate 
ozone impacts from precursor emissions for a specific nonattainment 
area or for case-by-case determinations. The TGD provides a framework 
and associated general methodology to apply existing or new empirical 
relationships between ozone and precursors to develop IPT ratios. The 
data sets and analyses included in the TGD may be used by air agencies 
as appropriate to develop IPT ratios; alternatively, air agencies may 
use existing modeling or generate their own modeling to provide the 
basis for the development of IPT ratios. The EPA believes the 
methodology presented in the TGD may be used by air agencies for 
developing default IPT ratios for specific nonattainment areas, and by 
air agencies and major stationary sources for developing appropriate 
case-by-case IPT ratios.\61\ The EPA is seeking comment on all aspects 
of the TGD.
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    \61\ The EPA does not propose in the regulations to require 
permitting authorities to use the data or methods described in the 
TGD.
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    In addition, in light of proposed changes to EPA's Guideline for 
Air Quality Models, published as Appendix W to 40 CFR part 51, which 
provide greater clarity regarding the use of

[[Page 81298]]

chemical transport modeling to estimate single-source ozone impacts 
from precursors, any empirical relationships deemed acceptable for 
estimating single-source compliance with the NAAQS under PSD permitting 
could also provide credible and suitable information for air agencies 
to establish area-specific IPT ratios for purposes of satisfying the 
NNSR offset requirements. The EPA is seeking comment on the use of 
technically credible relationships estimated with chemical transport 
models between single-source ozone impacts and precursors to provide 
the basis for an IPT ratio. Appendix W (if finalized, as proposed) 
provides guidelines for area-specific assessments of precursor 
emissions impacts on ozone and these guidelines may also support the 
development of case-by-case IPT ratios or area-specific default IPT 
ratios for ozone precursors.

G. Emissions Inventory and Emissions Statement Requirements

1. Background and Summary of Proposal
    The EPA is proposing to clarify its emissions inventory and 
emissions statement requirements in the context of this action by 
adding 40 CFR 51.1315. CAA sections 182(a)(1) and 182(a)(3)(A) require 
states to submit emissions inventories to the EPA. To clarify these 
statutory requirements within the context of implementing the 2008 
ozone NAAQS, the EPA added 40 CFR 51.1115 (80 FR 12264, 12314; March 6, 
2015). These statutory and regulatory authorities do not address the 
associated emissions statement requirements under CAA section 
182(a)(3)(B). For purposes of the 2015 ozone NAAQS we are proposing to 
add 40 CFR 51.1315, which will clarify requirements for the emissions 
inventories and emissions statements required by CAA sections 
182(a)(1), 182(a)(3)(A), and 182(a)(3)(B), respectively. While the 
proposed 40 CFR 51.1315 is similar to the existing 40 CFR 51.1115, 
these provisions are not identical, as discussed later. Moreover, we 
are also clarifying in this preamble how air agencies demonstrate 
compliance with CAA section 182(a)(3)(B) in the context of the 2015 
ozone NAAQS.
2. Emissions Inventories
    The emission inventory requirements for the 2008 ozone NAAQS, found 
at 40 CFR 51.1115, describe the criteria and timing for base year and 
periodic inventories required under CAA sections 182(a)(1) and 
182(a)(3)(A), respectively. For reference, the preamble to the final 
2008 Ozone NAAQS SIP Requirements Rule provides an extensive discussion 
of the EPA's rationale and approach for emission inventories (80 FR 
12289; March 6, 2015). In general, we provided that air agencies may 
rely, when appropriate, on their 3-year cycle inventory as described by 
the Air Emissions Reporting Requirements rule (AERR, codified in 40 CFR 
51, subpart A) to meet the 182(a)(3)(A) periodic inventory obligations, 
with additional requirements for the reporting of ozone season day 
emissions and treatment of partial-county inventories.\62\
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    \62\ States should consult the latest version of the guidance 
document titled ``Emission Inventory Guidance for Implementation of 
Ozone and Particulate Matter National Ambient Air Quality Standards 
(NAAQS) and Regional Haze Regulations,'' EPA-454/R-05-001 (latest 
final November 2005; revised draft April 2014) and any subsequent 
updates to that guidance that the EPA makes available at: https://www.epa.gov/air-emissions-inventories/emissions-inventory-guidance-implementation-ozone-and-particulate-matter.
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    To support the periodic emissions inventory requirement, the EPA is 
proposing revisions to the AERR point source reporting thresholds in 
AERR Table 1 (40 CFR 51, subpart A, appendix A) to be consistent with 
the major source thresholds for ozone nonattainment areas. These 
reporting thresholds are in tons of potential emissions per year. The 
existing AERR Table 1 includes Moderate area thresholds of 100 tpy for 
NOX and VOC, which are the same as the triennial thresholds 
for all areas. The existing AERR table also includes lower VOC 
thresholds for the Serious, Severe, and Extreme areas of 50, 25 and 10 
tpy. With this proposed revision, the AERR table would be updated to 
also explicitly include these same Serious, Severe and Extreme area 
thresholds for NOX. The same thresholds as have existed for 
VOC also apply for NOX, consistent with definition of 
``major source'' in both 40 CFR 70.2 and 40 CFR 71.2. In addition, the 
VOC and NOX thresholds also depend on whether the source is 
within an OTR in accordance with CAA 184(b)(2). Thus, the EPA proposes 
to include in the AERR table a 50 tpy potential-to-emit (PTE) VOC 
threshold for sources within an OTR and a 50 tpy PTE NOX 
threshold for sources both within an OTR and within a Moderate ozone 
nonattainment area. The latter requirement applies the same definition 
noted above in 40 CFR 70.2 and 40 CFR 71.2. Finally, this proposal 
removes the lower 100 tpy PTE carbon monoxide (CO) threshold from 
Appendix A for ozone nonattainment areas because there is no major 
source threshold for CO in the current or proposed implementing 
regulations for the ozone NAAQS. The EPA notes that these proposed 
revisions are technical corrections, and we are not proposing or 
accepting comment on any substantive revisions to the AERR itself.
    Air agencies are advised to check the EPA Web site for the 
currently approved mobile source models and to consult with the EPA 
Office of Transportation and Air Quality and their Regional office to 
determine the versions of models to use for their SIPs for the 2015 
ozone NAAQS. MOVES2014a, which incorporates both onroad and nonroad 
emissions estimates, is the most recently approved model for states 
other than California. The model and additional information are 
available at: http://www.epa.gov/otaq/models/moves/index.htm. Other 
appropriate methods should be used to estimate emissions of nonroad 
sources not included in the model. For California, consult with the EPA 
Region 9 for information on the latest approved version of the EMFAC 
(Emissions FACtors) model. EMFAC2014 is the most recently approved 
model.
    The EPA is proposing to otherwise adopt the same emission inventory 
requirements for the 2015 ozone NAAQS, based on the current approach 
articulated in the final 2008 Ozone NAAQS SIP Requirements Rule.
3. Emissions Statements
    For nonattainment areas, air agencies must develop, and include in 
their SIP, emission reporting programs for certain VOC and 
NOX sources in accordance with CAA section 182(a)(3)(B). The 
required state program defines how air agencies obtain emissions data 
directly from certain facilities, and these data, along with other 
information, are then reported to the EPA as part of SIP inventories 
required by CAA sections 182(a)(1) and 182(a)(3)(a). This state program 
is generally referred to as an emissions statement regulation, and it 
outlines how certain facilities must report emissions and facility 
activity data to an air agency, typically a state. Reports submitted to 
air agencies must be accompanied by ``a certification that the 
information contained'' in the report is ``accurate to the best 
knowledge'' of the facility.\63\ To properly implement the emissions 
reporting requirements, smissions statement regulations should be 
coordinated carefully with the data

[[Page 81299]]

elements that are required by the EPA (existing requirements at 40 CFR 
51.1115 and proposed at 40 CFR 51.1315). An air agency must submit the 
emissions statement regulation required by CAA section 182(a)(3)(B), or 
a written statement certifying a previously-approved regulation, to the 
EPA as a SIP revision for approval (see Section III.A.2 of this 
preamble). CAA section 110, in conjunction with 40 CFR 51.102, 103 and 
Appendix V, establishes the procedure for submitting a SIP revision.
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    \63\ Additional details on developing emissions statement 
regulations can be found in the guidance document titled ``Guidance 
on the Implementation of an Emission Statement Program (DRAFT),'' 
(July 1992) available at: https://www.epa.gov/air-emissions-inventories/implementation-emission-statement-program.
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V. Additional Considerations

    This section addresses several important requirements and policies, 
with one exception, the EPA is not proposing specific regulatory text 
due to lingering legal issues, scientific unknowns and uncertainties 
associated with developing and implementing new requirements and/or 
policies. The one exception concerns proposed new regulatory provisions 
that require air agencies to demonstrate RACM for Marginal areas for 
treatment under CAA section 179B (see Section V.D of this preamble). 
The EPA is using this notice, however, to solicit public comment on 
these requirements and policies to inform possible future actions.

A. Managing Emissions From Wildfire and Wildland Prescribed Fire

    The final 2008 Ozone NAAQS SIP Requirements Rule discussed the 
large contribution that wildfire can make to air pollution (including 
ozone), and wildfire's threat to public safety. The rule also 
recognized that this effect can be mitigated through management of 
wildland vegetation, including through prescribed fire. Such mitigation 
can help manage the contribution of fires to ozone levels in 
nonattainment areas. Therefore, the EPA recommended as guidance but not 
as a requirement of the final rule, if wildfire impacts are significant 
and contribute to exceedances of the standard, then air agencies should 
consider RACM for wildfires (which RACM could include a required 
program of prescribed fires). The EPA also recommended that air 
agencies should consider RACM for managing emissions from prescribed 
fires (including those prescribed fires conducted to reduce future 
wildfire emissions). The rule noted that information is available from 
the U.S. Department of the Interior (DOI) and the U.S. Department of 
Agriculture (USDA) Forest Service on smoke management programs and 
basic smoke management practices (BSMP). See 80 FR 12282.
    More recently, in its proposed implementation rule for the 
PM2.5 NAAQS, the EPA proposed to recommend as guidance, but 
not as a requirement of the final rule, if wildfire impacts are 
significant, and contributed to exceedances of the standard, then air 
agencies should consider RACM for wildfires (which RACM could include a 
required program of prescribed fires). The EPA also proposed to 
recommend that air agencies should consider RACM for managing emissions 
from prescribed fires (including those prescribed fires conducted to 
reduce future wildfire emissions). The proposal noted that information 
is available from the DOI and the USDA Forest Service on smoke 
management programs and BSMP. The EPA requested comment on the concept 
of, and practical considerations associated with RACM for wildfire and 
RACM for prescribed fire, including such issues as how such measures 
can be characterized in the emissions inventory and attainment 
demonstration and made federally enforceable for adoption in a SIP (80 
FR 15372; March 23, 2015). Upon consideration of public comments and 
further consultation with other federal agencies, the EPA recommended, 
as guidance for air agencies as they implement the final 
PM2.5 implementation rule, that air agencies follow a 
different approach to addressing RACM for wildland fire than the 
approach that the EPA proposed to recommend (81 FR 58038-39; August 24, 
2016). We are proposing the same recommended approach for purposes of 
implementing the 2015 ozone NAAQS, as discussed in this preamble.
    Before explaining this recommendation further, the EPA wishes to 
clarify that the recommendation is focused on wildland fire management. 
There are other uses of prescribed fire and other types of burning that 
occur in nonattainment areas, or that affect downwind nonattainment 
areas, such as burning of land clearing debris, agricultural burning, 
and burning of logging slash on land where the primary purpose of the 
logging is for commercial timber sale.\64\ The challenges with applying 
the traditional nonattainment planning framework that are raised in 
this discussion are particular to wildland fire, and the EPA believes 
that addressing these other uses of prescribed fire does not present 
nearly the same level of challenge, and thereby can still be 
accommodated within the nonattainment planning framework. For example, 
where these other types of burning currently contribute to ozone levels 
in a nonattainment area, air agencies may, with an adequate technical 
demonstration, be able to take credit for reductions resulting from 
improvement in smoke management techniques for these types of 
prescribed fire where the improvement results in a demonstrated 
reduction in impacts in the nonattainment area. The remainder of this 
discussion is not meant to address these categories, and is instead 
focused on prescribed fire on wildlands.
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    \64\ The EPA notes that some wildland logging operations are 
conducted for the same purposes as prescribed fire (e.g., reducing 
fuel load, ecosystem benefits). The fact that some of the removed 
trees may be sold as timber does not make commercial timber sale the 
primary purpose of such operations.
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    The EPA also wants to clarify that it is not the intention to in 
any way discourage federal, state, local or tribal agencies or private 
land owners from taking situation-appropriate steps to minimize impacts 
from prescribed fire emissions on wildland. The EPA encourages all land 
owners and managers to apply appropriate BSMP to reduce emissions from 
prescribed fires, especially where an air agency has determined that 
prescribed fires are a significant source affecting air quality. The 
EPA understands that the federal land managers (FLMs) apply these 
measures routinely and will be available to consult with other agencies 
and private parties interested in doing the same.
    However, for several reasons, the EPA does not believe it would be 
effective policy or technically appropriate to recommend that control 
measures for wildland fire be adopted into the SIP as enforceable 
measures and credited for emissions reductions (of ozone and 
precursors) that would help the area attain the standard.\65\ Instead, 
EPA recommends that ozone nonattainment plans (and in particular the 
attainment demonstrations) not expressly account for expected air 
quality changes over the planning period resulting from changes in the 
use of wildland prescribed fire to reduce future wildfires, or air 
quality changes over the planning period resulting from changes in 
wildland fire emissions due to a program of prescribed fire or due to 
any other cause including climate change. In most cases, state 
attainment demonstration modeling should assume that wildland

[[Page 81300]]

prescribed fire and wildfire emissions in the attainment year will be 
equal to, and have the same temporal and geographic pattern as, those 
assumed in the baseline inventory year.
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    \65\ These reasons include concerns raised by commenters about 
the difficulties associated with requiring or even encouraging 
states to incorporate wildland fire emissions into existing 
nonattainment planning procedures and practices under the CAA; high 
year-to-year variability and unpredictability with emissions from 
wildland fires; uncertainty in the amount of credit to give for 
reduced wildfire within the planning period and in the amount of 
benefit that exists after accounting for increases in prescribed 
fires within the planning period; and finally, the fact that air 
quality data actually influenced by fire events may ultimately be 
excluded under the provisions of the Exceptional Events Rule (40 CFR 
50.14).
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    The EPA acknowledges that some temporal and spatial patterns of 
fire emissions must still be assumed in the attainment demonstration in 
order to ensure that the required air quality modeling results in a 
realistic physical and chemical environment and a correspondingly 
realistic model response against which to analyze the changes from 
categories where express accounting of changes is still being done. 
This rule is not intended to constrain the options for states regarding 
the appropriate assumptions to make for fire emissions. Rather, it 
simply recommends that once this base level is established, ozone plans 
should not attempt to expressly project changes over the planning 
period in emissions from wildfires or prescribed fires on wildland 
within the nonattainment area, or in upwind areas included in the 
modeling domain, that are due to variability in wildfire occurrence or 
changes in the use of prescribed fire or other wildland fire management 
practices. Moreover, the EPA anticipates that changes in spatial and 
temporal patterns of wildfire will likewise be too uncertain for them 
to be allowed to have the effect of reducing or increasing the control 
requirement on conventional anthropogenic sources. The EPA therefore 
recommends that baseline wildland fire emissions should generally be 
held constant over the planning period, regardless of whether wildland 
fire management practices by land managers are expected, and possibly 
encouraged, to change.
    Air agencies still have flexibility in determining how best to 
represent baseline wildland fire emissions. As noted earlier, base year 
emission inventories for the nonattainment areas should represent the 
conditions leading to nonattainment and be consistent with inventories 
used for modeling. For fires, the EPA additionally encourages air 
agencies to use a representative mix of prescribed fire and wildfire in 
their inventories. Using PM2.5 as an example, some plans 
under previous PM2.5 NAAQS have estimated the actual fire 
emissions and temporal and spatial patterns from a given year and used 
this estimate as the assumed future baseline for planning, while others 
have used average emissions over multiple years. Other approaches may 
be appropriate as well. Moreover, regardless of the approach used, the 
EPA still encourages air agencies to submit actual wildfire and 
prescribed fire activity data that are critical to developing emissions 
estimates to the NEI as suggested in the AERR.
    A consequence of the recommendation of not expressly accounting for 
changes in wildland fires in attainment demonstrations is that measures 
to reduce emissions from wildland fires, such as prescribed fire to 
prevent catastrophic wildfires and for mitigation purposes or smoke 
management programs and BSMP for prescribed fires in wildland, need not 
be included as RACM for the respective fire types. This is because the 
changes in emissions due to such measures would not be accounted for in 
determining what is necessary for attainment and/or what would advance 
the attainment date, which is how the EPA is recommending that RACM be 
determined. So, for example, in an area that can attain in 6 years with 
measures that do not address wildland fire, the EPA does not recommend 
that states attempt to quantify whether increased prescribed fire could 
advance the attainment date by 1 year, due to aforementioned 
difficulties associated with such quantification.
    To be clear, nothing about this policy regarding RACM is intended 
to suggest that fires should be ignited in wildland (or elsewhere) 
without regard to the air quality or public health consequences. As 
noted earlier, the EPA believes these consequences are important to 
address, and intends to engage in dialogue with the FLMs, air agencies, 
tribes, state and private land owners and other stakeholders at 
appropriate times, such as during the process for the development of 
land management plans, about how land managers determine when and where 
prescribed fire is appropriate for particular wildlands and how to 
identify and implement appropriate mitigation measures. The policy 
simply makes clear the EPA's view regarding its recommendation for RACM 
for wildland fires.
    Finally, the EPA notes that, because a significant element of the 
rationale for this policy is the uncertainty in the timing of 
wildfires, we may reconsider this recommendation in the future, if 
adequate tools emerge that allow for predicting fire emissions with 
sufficient specificity. However, even if such tools emerge, due to 
inherent uncertainties it may be impossible to satisfactorily 
incorporate the use of such information into an attainment 
demonstration framework.

B. Transportation Conformity and General Conformity

1. What is conformity?
    Conformity is required under CAA section 176(c) to ensure that 
federal actions are consistent with (``conform to'') the purpose of the 
SIP. Conformity to the purpose of the SIP means that federal activities 
will not cause new air quality violations, worsen existing violations, 
or delay timely attainment of the relevant NAAQS or interim reductions 
and milestones. Conformity applies to areas that are designated 
nonattainment, and those nonattainment areas redesignated to attainment 
with a CAA section 175A maintenance plan after 1990 (``maintenance 
areas'').
    The EPA's Transportation Conformity Rule (40 CFR 51.390 and part 
93, subpart A) establishes the criteria and procedures for determining 
whether transportation activities conform to the SIP. These activities 
include adopting, funding or approving transportation plans, 
transportation improvement programs (TIPs) and federally supported 
highway and transit projects. The EPA first promulgated the 
Transportation Conformity Rule on November 24, 1993 (58 FR 62188), and 
subsequently published several amendments. We subsequently restructured 
the Transportation Conformity Rule in such a manner that existing 
conformity requirements will apply for any new or revised NAAQS (77 FR 
14979; March 14, 2012); the conformity rule, therefore, applies 
directly and does not need to be updated to reflect the 2015 ozone 
NAAQS. However, the EPA intends to issue an update to existing 
transportation guidance related to the implementation of the revised 
ozone standards. The updates to the existing guidance will address 
topics that include when conformity applies for the 2015 ozone NAAQS, 
when conformity may stop applying for the 2008 ozone NAAQS and the 
baseline year to be used by metropolitan planning organizations (MPOs) 
in nonattainment areas for the 2015 ozone NAAQS that are required to 
use one or both of the interim emissions tests to demonstrate 
conformity before such areas have adequate or approved motor vehicle 
emissions budgets for the 2015 ozone NAAQS (or adequate or approved 
budgets for a previous ozone NAAQS). For further information on 
transportation conformity rulemakings, policy guidance and outreach 
materials, see the EPA's Web site at http://www3.epa.gov/otaq/stateresources/transconf/policy.htm.
    With regard to general conformity, the EPA first promulgated 
general

[[Page 81301]]

conformity regulations in November 1993 (40 CFR part 51, subpart W and 
40 CFR part 93, subpart B). Subsequently, the EPA finalized revisions 
to the general conformity regulations on April 5, 2010 (75 FR 17254). 
The general conformity program ensures that federal actions not covered 
by the Transportation Conformity Rule will not interfere with the SIP. 
General conformity also fosters communications between federal agencies 
and state and local air quality agencies, provides for public 
notification of and access to federal agency conformity determinations 
and allows for air quality review of individual federal actions. More 
information on the general conformity program is available at http://www3.epa.gov/airquality/genconform/.
2. Why is the EPA discussing transportation and general conformity in 
this proposed rulemaking?
    The EPA is discussing transportation and general conformity in this 
proposed rulemaking in order to provide affected parties with 
information on when conformity must be implemented after nonattainment 
areas are designated for the 2015 ozone NAAQS. The information 
presented here is consistent with existing conformity regulations and 
statutory provisions that are not addressed by this ozone 
implementation rulemaking. Affected parties include state and local 
transportation and air quality agencies, MPOs, and federal agencies 
including the U.S. Department of Transportation (DOT), the U.S. 
Department of Defense, the DOI and the USDA.
3. When would transportation and general conformity apply to areas 
designated nonattainment for the 2015 ozone NAAQS?
    Transportation and general conformity will apply 1 year after the 
effective date of nonattainment designations for a new or revised ozone 
NAAQS including the 2015 ozone NAAQS. This is because CAA section 
176(c)(6) provides a 1-year grace period from the effective date of 
initial designations for any new or revised NAAQS before transportation 
and general conformity apply in areas newly designated nonattainment 
for a specific pollutant and NAAQS. The grace period applies to newly 
designated nonattainment for a new or revised ozone NAAQS including the 
2015 ozone NAAQS even if the area had been designated nonattainment for 
a prior ozone NAAQS. With regard to general conformity, the EPA's April 
2010 revisions to its general conformity regulations (see 75 FR 17277; 
April 5, 2010) apply the same 1-year grace period to all new or revised 
NAAQS--including the 2015 ozone NAAQS--for purposes of general 
conformity.
    With regard to transportation conformity, the conformity grace 
period will apply to all areas designated nonattainment for a new or 
revised ozone NAAQS including the 2015 ozone NAAQS. The requirements 
differ depending on whether the nonattainment area includes any part of 
an MPO designated under 23 United States Code (U.S.C.) section 134. 
Within 1 year after the effective date of the initial nonattainment 
designation for a given pollutant and NAAQS, the MPOs and DOT must make 
a conformity determination with regard to that pollutant and standard 
for all of the metropolitan transportation plans and TIPs in the 
nonattainment area. The conformity requirements for surrounding ``donut 
areas,'' including the application of the 1-year conformity grace 
period, are generally the same as those for metropolitan areas.\66\ If, 
at the end of the grace period, the MPO and the DOT have not made a 
transportation plan and TIP conformity determination for the relevant 
pollutant and standard, the area would be in a conformity ``lapse.'' 
During a conformity lapse, only certain projects can receive additional 
federal funding or approvals to proceed.\67\ The practical impact of a 
conformity lapse will vary from area to area. Finally, the 1-year 
conformity grace period also applies to project level conformity 
determinations.
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    \66\ For the purposes of transportation conformity, a ``donut'' 
area is the geographic area outside a metropolitan planning area 
boundary, but inside a designated nonattainment or maintenance area 
boundary that includes an MPO (40 CFR 93.101).
    \67\ During a conformity lapse, only the following projects can 
receive additional federal approvals and funding:
    1. Projects that are exempt from transportation conformity such 
as elimination of at-grade railroad crossings, repaving roadways, 
widening narrow pavements and reconstructing bridges as long as new 
travel lanes are not added because they are exempt from conformity; 
and
    2. Transportation control measures included in approved SIPs 
because these projects provide emissions reductions toward attaining 
or maintaining the NAAQS.
    Additionally, any project or project phase that was funded or 
approved prior to a lapse may proceed but no additional funding or 
approval decisions may be made until the lapse is ended.
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    Isolated rural nonattainment areas are areas that do not contain or 
are not part of an MPO (40 CFR 93.101).\68\ Conformity requirements for 
isolated rural nonattainment areas can be found at 40 CFR 93.109(g). 
One year after the effective date of the initial nonattainment 
designation for a given pollutant and NAAQS, conformity requirements 
with regard to that pollutant and standard would apply in any 
nonattainment areas that are isolated rural areas. Per the 
Transportation Conformity Rule, at the point that a transportation 
project in an isolated rural area needs federal funding or approval, 
the project sponsor (e.g., the state DOT) would prepare the 
documentation required for the transportation conformity determination, 
including a regional emissions analysis. The Federal Highway 
Administration and Federal Transit Administration could then make the 
transportation conformity determination. This conformity determination 
may occur significantly after the 1-year grace period has ended. See 
the EPA's July 1, 2004, final rule for further background on how the 
EPA has implemented this conformity grace period in metropolitan, donut 
and isolated rural areas (69 FR 40008-14).\69\
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    \68\ An isolated rural nonattainment area as defined in the 
transportation conformity rule is distinct from a CAA section 182(h) 
rural transport area. An isolated rural area for transportation 
conformity purposes is a nonattainment area that does not contain or 
is not part of any metropolitan planning area as designated under 
federal transportation planning regulations. (40 CFR 93.101) A rural 
transport area as defined in CAA section 182(h) is a nonattainment 
area that is not adjacent to or part of any metropolitan statistical 
area or consolidated metropolitan area, if one exists. Such an area 
may be treated as a rural transport area if the Administrator finds 
that sources of VOC and, if relevant, NOX emissions in 
the area do not make a significant contribution to the ozone 
concentrations measured in the area or other areas.
    \69\ Also, see the EPA's transportation conformity Web site for 
more information, including EPA's ``Transportation Conformity 
Guidance for 2008 Ozone NAAQS Nonattainment Areas'' at: http://www3.epa.gov/otaq/stateresources/transconf/2008naaqs.htm.
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4. Would transportation and general conformity apply for the 2008 ozone 
NAAQS once that NAAQS is revoked?
    The CAA only requires transportation and general conformity 
determinations in areas that are designated nonattainment or 
maintenance for a given pollutant and standard.\70\ As discussed in 
Section IV.B of this preamble, the EPA is proposing two options for 
revoking the 2008 ozone NAAQS. One option is to revoke the 2008 ozone 
NAAQS for all purposes as has been done for the 1997 and 1-hour ozone 
NAAQS one year after the effective date of designations for the 2015 
ozone NAAQS. The second option is to revoke the 2008 ozone NAAQS in 
areas that have always been designated attainment for that NAAQS and in 
areas that have been redesignated to

[[Page 81302]]

attainment with an approved CAA section 175A maintenance plan. Under 
the second option, the 2008 ozone NAAQS would be revoked in all 
attainment areas for that NAAQS one year after the effective date of 
designations for the 2015 ozone NAAQS. EPA will continue to redesignate 
nonattainment areas for the 2008 ozone NAAQS after the initial 
revocation. In those areas that are redesignated at a later date, the 
2008 ozone NAAQS will be revoked on the effective date of the 
redesignation but in no case sooner than 1 year after the effective 
date of the designation for the 2015 ozone NAAQS for the area. 
Therefore, transportation and general conformity would no longer apply 
for purposes of the 2008 ozone NAAQS as of the time those standards 
(and, thus, an area's designation for those standards) are revoked. 
Accordingly, transportation and general conformity determinations would 
no longer be required in existing 2008 ozone NAAQS nonattainment and 
maintenance areas after the 2008 ozone NAAQS is revoked under either of 
the proposed options. However, under option 2, the revocation for areas 
designated as nonattainment for the 2008 ozone NAAQS would not occur 
one year after the effective date of designations for the 2015 ozone 
NAAQS. The revocation for these areas would only occur on the effective 
date of their redesignation to attainment for the 2008 ozone NAAQS if 
such redesignation were to occur.
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    \70\ Maintenance areas are areas that have been redesignated to 
attainment with an approved CAA section 175A maintenance plan.
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    Under our current Transportation Conformity Rule, the latest 
approved or adequate emission budgets for a prior ozone NAAQS (i.e., 
the 2008, 1997 or the 1-hour ozone NAAQS) would continue to be used in 
transportation conformity determinations for the 2015 ozone NAAQS until 
emission budgets are established and found adequate or are approved for 
the 2015 ozone NAAQS (77 FR 14981, 14981; April 20, 1990). The use of 
the latest approved or adequate motor vehicle emission budgets for a 
prior ozone NAAQS as part of transportation conformity determinations 
in nonattainment areas for the 2015 NAAQS until 2015 ozone motor 
vehicle emissions budgets are available has been recognized as a 
``control'' for purposes of defining anti-backsliding requirements as 
discussed in section IV.B of this proposal. South Coast Air Qual. Mgmt. 
Dist. v. EPA, 489 F.3d at 1248 (clarifying South Coast, 472 F.3d at 
904-05). This requirement is already codified at 40 CFR 93.109(c)(2).
5. What impact will the implementation of the 2015 ozone NAAQS have on 
an air agency's transportation and/or general conformity SIP?
    As long as the EPA does not make specific changes to its 
transportation or general conformity regulations, air agencies should 
not need to revise their transportation and/or general conformity SIPs. 
The EPA is not proposing any changes to its transportation conformity 
or general conformity regulations. Air agencies with new nonattainment 
areas may need to revise conformity SIPs in order to ensure the state 
regulations apply in any newly designated areas.
    However, if this is the first time that transportation conformity 
will apply in a state, the air agency is required by the statute and 
EPA regulations to submit a SIP revision that addresses three specific 
transportation conformity requirements that address consultation 
procedures and written commitments to control or mitigation measures 
associated with conformity determinations for transportation plans, 
TIPs or projects (40 CFR 51.390). Additional information and guidance 
can be found in the EPA's ``Guidance for Developing Transportation 
Conformity State Implementation Plans (SIPs)'' (http://www3.epa.gov/otaq/stateresources/transconf/policy/420b09001.pdf).
6. Are there any other impacts related to general conformity based on 
implementation of the 2015 ozone NAAQS?
    As air agencies develop SIP revisions for the 2015 and future ozone 
NAAQS, the agency recommends that state and local air quality agencies 
work with federal agencies with large facilities (e.g., commercial 
airports, ports and large military bases) that might take actions 
subject to the general conformity regulations to establish an emissions 
budget in the SIP for those facilities in order to facilitate future 
conformity determinations under the conformity regulations. Such a 
budget could be used by federal agencies in determining conformity or 
identifying mitigation measures for particular projects at those 
facilities, but only if the budget level is included and identified in 
the SIP.
    In a few cases, tracts of land under federal management may also be 
included in nonattainment and maintenance area boundaries. The role of 
fire in these areas should be assessed and emissions budgets developed 
in concert with those federal land management agencies. In such areas 
the EPA encourages air agencies to consider in any baseline, modeling 
and SIP attainment inventory used and/or submitted to include emissions 
expected from projects subject to general conformity, including 
emissions from wildland fire that may be reasonably expected in the 
area. Where appropriate, air agencies may consider developing plans for 
addressing wildland fuels in collaboration with land managers and 
owners. Information is available from DOI and USDA Forest Service on 
the ecological role of fire and on smoke management programs and 
BSMP.\71\
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    \71\ USDA Forest Service and Natural Resources Conservation 
Service, Basic Smoke Management Practices Tech Note, October 2011, 
http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1046311.pdf.
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C. Requirements for Contingency Measures in the Event of Failure To 
Meet a Milestone or To Attain

    For purposes of the 2015 ozone NAAQS, the EPA is proposing no 
changes to the requirements for contingency measures articulated in the 
final 2008 Ozone NAAQS SIP Requirements Rule (80 FR 12285; March 6, 
2015).\72\ As required by the CAA, nonattainment areas must include in 
their SIPs contingency measures consistent with CAA section 172(c)(9), 
and those classified Serious or higher must include contingency 
measures that are also consistent with CAA section 182(c)(9), with 
limited exceptions for Extreme nonattainment areas relying on plan 
provisions approved under CAA section 182(e)(5). These contingency 
measures must be fully adopted rules or measures that are ready for 
implementation quickly upon failure to meet milestones or attain by the 
attainment deadline. Per EPA guidance,\73\ these measures should 
provide 1 year's worth of reductions, or

[[Page 81303]]

approximately 3 percent of the baseline emissions inventory. If these 
adopted contingency measures are insufficient to attain the standard, 
an air agency must conduct additional control measure development and 
implementation for the area as necessary to correct the shortfall.
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    \72\ The EPA acknowledges that the U.S. Court of Appeals for the 
9th Circuit recently issued an opinion in Bahr v. EPA, No. 14-72327, 
2016 U.S. App. LEXIS 16667 (9th Cir. Sept. 12, 2016), which rejected 
EPA's longstanding interpretation of section 172(c)(9) in the 
context of a SIP for particular matter standards that allowed states 
to rely on control measures that are already in effect as a valid 
means to meet the contingency measure requirement. The EPA is still 
in the process of assessing and determining how to address the Bahr 
decision, but does not currently plan to alter the Agency's 
longstanding interpretation outside of the 9th Circuit, especially 
in light of a prior decision from the U.S. Court of Appeals for the 
5th Circuit upholding that interpretation. See Louisiana Envt'al 
Action Network v. EPA, 382 F.3d 575 (5th Cir. 2004); see also 40 CFR 
56.5(b).
    \73\ August 23, 1993, memorandum from Michael H. Shapiro, Acting 
Assistant Administrator for Air and Radiation, to Regional Air 
Directors, ``Guidance on Issues Related to 15 Percent Rate-of-
Progress Plans.'' Available at: http://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/19930823_shapiro_15pct_rop_guidance.pdf.
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    Regarding content of the 1 year's worth of reductions covered by 
the contingency measures, the EPA is proposing to continue to allow 
these reductions of the contingency measures to be based entirely or in 
part on NOX controls if the area has completed the initial 
15 percent ROP VOC reduction required by CAA section 182(b)(1)(A)(i) 
and an air agency's analyses have demonstrated that NOX 
substitution (entirely or in part) would be effective in bringing the 
area into attainment. The EPA will continue to allow the use of federal 
measures providing ongoing reductions into the future to be used meet 
contingency measure requirements for the 2015 ozone NAAQS, consistent 
with the EPA's longstanding policy.
    With respect to Extreme ozone nonattainment areas, CAA section 
182(e)(5) allows the agency to exercise discretion in approving Extreme 
area attainment plans that rely, in part, on the future development of 
new control technologies or improvements of existing control 
technologies, where certain conditions are met. This discretion can be 
applied as long as an air agency has demonstrated that: All RACM, 
including RACT, have been included in the plan; the area's RFP 
demonstration during the first 10 years after designation does not rely 
on anticipated future technologies; and the air agency has submitted 
enforceable commitments to timely develop and adopt contingency 
measures to be implemented if the anticipated future technologies do 
not achieve planned reductions. The EPA is proposing to continue to 
allow air agencies to submit, for Extreme nonattainment areas, 
enforceable commitments to develop and adopt contingency measures 
meeting the requirements of 182(e)(5) to satisfy the requirements for 
both attainment contingency measures in CAA sections 172(c)(9) and 
182(c)(9). These enforceable commitments must obligate the air agency 
to submit the required contingency measures to the EPA no later than 3 
years before any applicable implementation date, in accordance with CAA 
section 182(e)(5).\74\ We note that this does not, however, relieve air 
agencies from obligations to submit contingency measures as required by 
CAA sections 172(c)(9) and 182(c)(9) for periods in the first 10 years 
after designation.
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    \74\ For example, where a state intends to rely on CAA section 
182(e)(5) commitments to satisfy the CAA section 182(c)(9) 
contingency measure requirement for an RFP milestone in year 2027, 
the commitments must obligate the state to submit adopted 
contingency measures to the EPA no later than 2024 (i.e., 3 years 
before RFP contingency measures for 2027 would be implemented).
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D. International Transport and Background Ozone

    Most modeled ozone air quality values that exceed the NAAQS in the 
United States (U.S.) are due primarily to emission sources within the 
U.S. However, domestic ozone air quality can also be affected by 
sources of emissions located outside of the U.S. These contributions to 
U.S. ozone concentrations from sources outside of the U.S., which can 
be from nearby sources in a bordering country or from sources many 
thousands of miles away,\75\ can affect to varying degrees the ability 
of some areas to attain and maintain the 2015 ozone NAAQS. The EPA will 
continue to work with our domestic and international partners to better 
understand the extent and implications of transboundary flows of air 
pollutants and, where possible, to mitigate their impact on U.S. 
domestic air quality.
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    \75\ Observational and modeling studies have shown that 
international ozone precursor emissions can lead to ozone formation 
within the atmospheric boundary layer over far-upwind areas. When 
meteorological conditions are favorable, this ozone can be 
transported within the mid- and upper troposphere where ozone 
lifetimes can exceed one week. Eventually, these ozone plumes can 
mix down to the surface and contribute to local ozone concentrations 
within the U.S. (Task Force on Hemispheric Transport of Air 
Pollution, 2010).
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    Congress recognized that some nonattainment areas may be impacted 
not only by local sources of ozone or ozone precursor emissions, but 
also sources of emissions from outside of the U.S. Through CAA section 
179B, Congress provided the EPA with the authority to approve 
attainment plans for areas that could attain the relevant NAAQS by the 
statutory attainment date ``but for'' emissions emanating from outside 
the U.S. When applicable, this CAA provision relieves states from 
imposing control measures on emissions sources in the state's 
jurisdiction beyond those necessary to address reasonably controllable 
emissions from within the U.S. Specifically, CAA section 179B(a) 
provides that the EPA shall approve an attainment plan for such an area 
if: (i) The attainment plan meets all other applicable requirements of 
the CAA, and (ii) the submitting state can satisfactorily demonstrate 
that ``but for emissions emanating from outside the United States,'' 
the area would attain and maintain the relevant NAAQS. In addition, CAA 
section 179B(b) applies specifically to the ozone NAAQS and provides 
that if a state demonstrates that an ozone nonattainment area would 
have timely attained the NAAQS by the applicable attainment date ``but 
for emissions emanating from outside of the United States,'' then the 
area can avoid extension of the ozone attainment dates pursuant to CAA 
section 181(a)(5), the application of fee provisions of CAA section 
185, and the mandatory reclassification provisions under CAA section 
181(b)(2) \76\ for areas that fail to attain the ozone NAAQS by the 
applicable attainment date. Section 179B, thus, provides an important 
tool that provides states relief from the requirement to demonstrate 
attainment--and from the more stringent planning requirements that 
would result from failure to attain--in areas where, even though the 
air agency has taken appropriate measures to address air quality in the 
influenced area, emissions from outside of the U.S. prevent attainment.
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    \76\ It is EPA's longstanding position that the Clean Air Act 
contained an erroneous reference to section 181(a)(2) instead of 
181(b)(2) in 179B(b). See ``State Implementation Plans; General 
Preamble for the Implementation of Title I of the Clean Air Act 
Amendments of 1990,'' 57 FR 13498, 13569 fn. 41 (April 16, 1992).
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    In the 2008 ozone SIP Requirements Rule, the EPA stated that a 
section 179B demonstration could include consideration of any emissions 
from North American or intercontinental sources. (80 FR 12293). The EPA 
also stated at that time that it did not believe use of section 179B 
was limited to nonattainment areas adjoining international borders. Id. 
at 12294. The EPA notes, however, that the science review conducted as 
part of the 2015 ozone NAAQS suggests that the influence of 
international sources on U.S. ozone levels will be largest in locations 
that are in the immediate vicinity of Mexico or Canada (80 FR 65292, 
65444; October 26, 2015). The EPA, therefore, anticipates that section 
179B will most often be used by states with areas along the border with 
Mexico and Canada. Historically, the EPA has used CAA section 179B 
authority to approve attainment plans in the immediate vicinity of the 
Mexican border, including El Paso, Texas,\77\ Imperial Valley, 
California,\78\ and

[[Page 81304]]

Nogales, Arizona.\79\ Consistent with the particular showing required 
by the statutory language, the EPA will consider section 179B 
demonstrations on a case-by-case basis. The EPA asks for comment on 
whether the opportunity for such a demonstration should be limited to 
nonattainment areas adjoining international borders, and on any 
technical and legal basis for determining whether it is appropriate to 
have, or conversely whether it is appropriate not to have, such a 
limitation.
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    \77\ 59 FR 2532 (January 18, 1994); 68 FR 39457 (July 2, 2003); 
69 FR 32450 (June 10, 2004).
    \78\ 66 FR 53106 (October 19, 2001), overturned in Sierra Club 
v. EPA, et al., 352 F.3d 1186 (9th Cir. 2003).
    \79\ 77 FR 58962 (September 25, 2012).
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    Even if an area is impacted by emissions from outside the U.S., CAA 
section 179B does not affect the designations process.\80\ The 
designations process is meant to protect public health and welfare. 
Designating an area nonattainment for a particular NAAQS ensures that 
the public is informed that the air quality in a specific area does not 
meet the standard. Congress determined that in nonattainment areas, 
there should be adequate safeguards to protect public health and 
welfare. For example, Congress required such areas to have NNSR 
permitting programs, to ensure that air quality is not further 
degraded. Accordingly, areas with design values above the 2015 ozone 
NAAQS will be designated nonattainment and will be classified with a 
classification as indicated by actual ambient air quality. As a result 
of designation and classification, the state is subject to the 
applicable requirements, including NNSR, conformity, and other measures 
prescribed for nonattainment areas by the CAA. Section 179B of the CAA 
does not provide for any relaxation of mandatory emissions control 
measures (including contingency measures) or the prescribed emissions 
reductions; it only eliminates the obligation for an attainment 
demonstration that demonstrates attainment and maintenance of the 
NAAQS, which is conditioned upon the state meeting all other attainment 
plan requirements,\81\ and voids certain consequences of an area's 
failure to attain, including mandatory reclassifications.
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    \80\ Monitoring data cannot be excluded for a determination of 
whether an area has attained a NAAQS based solely on the fact the 
data are affected by international transport. However, such data may 
be excluded from consideration if they were significantly influenced 
by exceptional events as described in CAA section 319(b). Where 
international transport meets the criteria and procedural 
requirements contained in the EPA's Exceptional Events Rule (40 CFR 
50.14), it may be addressed by that rule. See 81 FR 68216 (October 
3, 2016).
    \81\ For a more detailed description of attainment planning 
requirements, see Section III.A of this preamble.
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    CAA section 179B does not alter the CAA's general construct 
expressed in subpart 1 of part D that states with nonattainment areas 
are expected to adopt reasonable emissions controls to lessen emissions 
of criteria pollutants to promote citizen health protection. The 
construct ensures that states will take reasonable actions to mitigate 
the public health impacts of exposure to ambient levels of pollution 
that violate the NAAQS by imposing reasonable control measures on the 
sources that are within the jurisdiction of the state regardless of 
impacts from interstate or international emissions. The primary purpose 
of part D of Title I of the CAA is to achieve emission reductions so 
that people living in a nonattainment area receive the public health 
protection intended by the NAAQS.
    Marginal ozone nonattainment areas are not generally required to 
implement reasonably available control technology requirements under 
subpart 2 of part D of Title 1 of the CAA. If an air agency were to 
apply for treatment under CAA section 179B(b) to avoid mandatory 
reclassification of a Marginal area after its failure to attain by the 
applicable attainment date, an area could continue to remain Marginal 
and, therefore, never implement reasonable emissions controls.
    The EPA believes that adopting an interpretation of CAA section 
179B that would allow people to continue to be subjected to levels of 
ozone above the NAAQS that a state could reasonably reduce--in this 
case not to attainment level, but to a level below the current level--
would be antithetical to the objectives of the CAA. The EPA believes it 
is appropriate for the Administrator to take this general construct of 
the CAA into account in determining during the application of CAA 
section 179B whether, ``to the satisfaction of the Administrator,'' an 
area would have attained the ozone NAAQS by the applicable attainment 
date but for emissions emanating from outside of the U.S. Accordingly, 
the EPA is proposing and seeking comment on a requirement that all 
demonstrations under CAA section 179B(b), regardless of an area's 
classification (including nonattainment areas classified as Marginal), 
must include a showing that the air agency adopted all RACM, including 
RACT, for the area in accordance with CAA section 172(c)(1), 42 U.S.C. 
7502(c)(1). Under this interpretation, if the air agency did not adopt 
reasonable control measures before making a section 179B(b) 
demonstration, it will be missing a critical component of the 
demonstration that the area would have attained the ozone NAAQS by the 
attainment date ``but for'' international impacts, namely a showing 
that the area could otherwise attain by application of reasonable 
controls on sources of emissions that are within the state's 
jurisdiction.\82\ We are proposing to add new regulatory provisions at 
40 CFR 51.1309 to establish that air agencies must also demonstrate 
RACM for Marginal areas for treatment under CAA section 179B.
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    \82\ With respect to the demonstration under CAA section 
179B(a), regardless of the nonattainment area's classification, 
where a plan can demonstrate that an area will attain the NAAQS by 
the attainment date after adopting all reasonable control measures, 
and, as such, would be potentially approvable by the EPA, such a 
plan would not also be eligible for approval under CAA section 
179B(a) by simply omitting these measures.
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    The EPA encourages air agencies to coordinate with their EPA 
regional office to identify approaches to evaluate the potential 
impacts of international transport and to determine the most 
appropriate information and analytical methods for each area's unique 
situation. The EPA will also work with air agencies that are developing 
attainment plans for which CAA section 179B is relevant, and ensure the 
air agencies have the benefit of the EPA's understanding of 
international transport of ozone and ozone precursors. Air agencies are 
encouraged to consult with their EPA Regional office to establish 
appropriate technical requirements for these analyses. The EPA invites 
comment as to whether the EPA should develop technical guidance for the 
``but for'' analysis in a section 179B demonstration, and invites 
comment about which methodologies and tools would be most effective to 
help states develop section 179B demonstrations.
    With respect to the larger issue of background ozone (or U.S. 
background, (USB)), the EPA has solicited input from air agencies, 
tribes, and interested stakeholders on aspects of USB that are relevant 
to attaining the 2015 ozone NAAQS in a manner consistent with the 
provisions of the CAA.\83\ To establish a common understanding and 
foundation for discussion, the EPA released a white paper titled, 
``Implementation of the 2015 Primary Ozone NAAQS: Issues Associated 
with Background Ozone'' in December 2015, and held a workshop in 
February 2016 to discuss information in the white paper.\84\
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    \83\ For purposes of NAAQS implementation, the EPA considers 
background ozone to be any ozone formed from sources or processes 
other than U.S. manmade emissions of NOX, VOCs, methane 
and CO.
    \84\ The white paper and other workshop details are available 
at: https://www.epa.gov/ozone-pollution/background-ozone-workshop-and-information.

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[[Page 81305]]

    Workshop attendees included representatives of state, local and 
tribal air agencies, and other interested stakeholders. A general theme 
among attendee comments was a concern that the EPA is underestimating 
the magnitude and effects of USB, and that available policy solutions 
do not provide meaningful relief from nonattainment designations in 
affected areas.\85\ The EPA continues to refine and conduct its 
national and global model simulations to better characterize USB, and 
is actively evaluating the need for further guidance and/or rules to 
address USB based on feedback received.
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    \85\ A high-level summary of workshop feedback is available at: 
https://www.epa.gov/sites/production/files/2016-03/documents/bgo3-high-level-summary.pdf. Additional written comments from interested 
parties are located in a separate EPA docket at http://www.regulations.gov (Docket ID No. EPA-HQ-OAR-2016-0097).
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    The EPA also recently finalized revisions to the Exceptional Events 
Rule to further facilitate review and approval of exceptional events 
that contribute to USB, such as stratospheric intrusions and wildfires 
(81 FR 68216; October 3, 2016).

E. Additional Policies and Programs for Achieving Emissions Reductions

1. Multi-Pollutant Planning
    Increasingly, state air agencies are considering multi-pollutant 
emission reduction strategies such as energy efficiency and renewable 
energy (EE/RE) requirements as compliance options for CAA plans and EPA 
encourages this multi-pollutant approach when assessing compliance 
options for ozone RFP and attainment demonstration SIPs. Many states 
are already implementing cost-effective EE/RE requirements that reduce 
all types of power generation related emissions (including carbon 
dioxide, NOX, PM2.5, SO2, and 
hazardous air pollutants). Effectively assessing these approaches will 
require strong working relationships between state energy and 
environmental officials. As state Public Utility Commissions (PUC) and 
state energy offices implement, increase the stringency of, or adopt 
new EE/RE requirements, their expertise can assist air agencies to 
incorporate the NOX emission impacts into ozone RFP and 
attainment demonstration SIPs.
    The EPA discussed this approach more completely in the final Clean 
Power Plan (CPP) \86\ and in an accompanying Technical Support Document 
(TSD) titled ``Incorporating RE and Demand-Side EE into State Plan 
Demonstrations.'' \87\ States would be able to use EE/RE requirements 
as a compliance option in their state plans to meet the CPP's carbon 
dioxide emission reduction targets for existing fossil-fired electric 
generating units (EGUs), and achieve a co-benefit of reducing 
NOX emissions that would be beneficial to managing ozone 
formation.
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    \86\ Carbon Pollution Emission Guidelines for Existing 
Stationary Sources: Electric Utility Generating Units; Final Rule 
(Clean Power Plan) (80 FR 64662; October 23, 2015). See, e.g., West 
Virginia v. EPA, No. 15A773, Order at 1 (U.S. Feb. 9, 2016).
    \87\ U.S. EPA (October 2015) Clean Power Plan TSD: Incorporating 
RE and Demand-Side EE Impacts into State Plan Demonstrations 
available at: https://www.epa.gov/sites/production/files/2015-11/documents/tsd-cpp-incorporating-re-ee.pdf.
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    The EPA has available several resources to help air agencies 
incorporate these multi-pollutant strategies in NAAQS SIPs/TIPs. 
Resources include the ``Roadmap for Incorporating EE/RE Programs and 
Policies in NAAQS SIPs/TIPs'' \88\ (released August 2012) and the 
AVoided Emissions geneRation Tool (AVERT), a tool for quantifying 
NOX, SO2 and CO2 avoided emissions 
\89\ (released February 2014). The Roadmap describes four pathways 
(baseline emissions projection, control strategy, emerging/voluntary 
measures, and weight of evidence determination) by which EE/RE policies 
and programs could be included in a SIP. Each pathway is appropriate in 
certain circumstances (existing vs. new EE/RE, control vs. voluntary 
measures, etc.) and the Roadmap can help decision-makers consider their 
options as they decide which pathway(s) to pursue for incorporating EE/
RE policies and programs into SIP/TIP demonstrations. The Roadmap's 
Appendix I also presents several methods available for quantifying the 
avoided NOX emissions from fossil fuel generation as a 
result of electricity savings from EE/RE policy/program 
implementation.\90\
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    \88\ Roadmap for Incorporating EE/RE Programs and Policies in 
NAAQS SIPs/TIPs available at: http://www3.epa.gov/airquality/eere/manual.html.
    \89\ AVERT available at: http://www3.epa.gov/avert/.
    \90\ Available at: http://www3.epa.gov/airquality/eere/pdfs/appendixI.pdf.
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    The EPA's tool, AVERT, can help planners in quantifying the 
emissions reductions that result from EE/RE policies and programs. 
AVERT outputs are readily available for SMOKE formatting to incorporate 
the emission impacts into air quality models.
2. Energy Efficiency/Renewable Energy Policies and Programs
    a. State-level EE/RE Requirements. State PUCs, primarily through 
their utilities, have in recent years been rapidly increasing resources 
devoted to EE programs. In the five years spanning 2006 to 2011, 
budgets for EE programs more than tripled, from $1.6 billion to $5.9 
billion. Additionally, EE spending is projected to continue to grow at 
a substantial rate.\91\ As of March 2015, 23 states have mandatory 
energy efficiency requirements, two states have voluntary targets, and 
two states allow energy efficiency as a compliance option for their 
renewable portfolio standard.\92\
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    \91\ American Council for an Energy-Efficient Economy (ACEEE) 
2013 State Energy Efficiency Scorecard. November 2013. Available at 
http://www.aceee.org/state-policy/scorecard/.
    \92\ U.S. EPA 2015. Energy and Environmental Guide to Action, 
Chapter 4 available at: http://www3.epa.gov/statelocalclimate/documents/pdf/GTA_Chapter_4.1_508.pdf.
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    Also, state-level RE requirements have been implemented in 29 
states plus Washington, DC, representing all regions of the 
country.\93\ Between the years 2020 and 2030, many state-level 
renewable portfolio standard (RPS) programs require electric utilities 
to serve from 15 to 40 percent of their retail sales with renewable 
power.\94\
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    \93\ RE requirements include Renewable Portfolio Standards or 
state-enacted RE requirements on a Mega-Watt (MW) basis. Database of 
State Incentives for Renewables and Efficiency, March 2013. 
Available at: http://www.dsireusa.org. Accessed January 3, 2016.
    \94\ U.S. EPA. 2015 Energy and Environment Guide to Action, 
Chapter 5 available at: http://www3.epa.gov/statelocalclimate/documents/pdf/guide_action_chapter5.pdf.
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    In an effort to examine the effects of these programs, EPA 
developed a counterfactual EE/RE scenario for a couple of areas that 
were nonattainment for EPA's 2008 ozone NAAQS, including the New York-
New Jersey-Connecticut area.\95\ In these illustrative examples the EPA 
used AVERT to approximate the potential emissions that would have been 
emitted into the atmosphere without current state-level EE/RE 
requirements. For the New York-New Jersey-Connecticut area, the EPA 
estimated that the current state-level RE requirements \96\ would avoid 
over 24 tons per summer day of NOX in 2020, and the current 
state-level EE

[[Page 81306]]

programs \97\ would avoid nearly 17 tons per summer day of 
NOX in 2020.\98\
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    \95\ This area encompasses eight counties in New York, 12 
counties in New Jersey, and three counties in Connecticut. The EPA's 
analysis is described in the Technical Support Document 
``Demonstrating NOX Emission Reduction Benefits of State-
Level Renewable Energy and Energy Efficiency Policies'' available in 
the docket.
    \96\ The 2020 RE requirements in each state are different and 
range from 20 percent-30 percent.
    \97\ The EE programs used in each state are different. 
Connecticut's estimated annual efficiency savings is 2.8 percent, 
New York's target was 15 percent savings from baseline by 2015, and 
New Jersey incentivized efficiency improvements through a funding 
program of $265 million in FY2014.
    \98\ For context, the RFP plan for the New York-New Jersey-
Connecticut 1997 ozone NAAQS nonattainment area included a 2008 
NOX emissions projection of 269 tons per summer day.
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3. Land Use Planning
    Air agencies may also wish to consider strategies that foster more 
efficient urban and regional development patterns as a long-term air 
pollution control measure. Resources include the U.S. Department of 
Housing and Development--DOT-EPA Partnership for Sustainable 
Communities, as well as the policy and technical guidance documents on 
land use and related travel efficiency available on the EPA's Office of 
Transportation and Air Quality Web site.\99\ These documents provide 
communities with the information they need to better understand the 
link between air quality, transportation and land use, and how certain 
land use policies have the potential to help local areas achieve and 
maintain healthy air quality. The documents also include methods to 
help communities account for the air quality benefits of their local 
land use in their air quality plans.
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    \99\ See http://www.epa.gov/otaq/stateresources/policy/pag_transp.htm.
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    If wildfire impacts are significant in a particular area, air 
agencies and communities may be able to lessen the impacts of wildfires 
by working collaboratively with land managers and land owners to employ 
various mitigation measures including taking steps to minimize fuel 
loading in areas vulnerable to fire.
4. Travel Efficiency
    Areas may also consider incorporating travel efficiency strategies, 
such as new or expanded mass transit options, commuter strategies, 
system operations (e.g., ramp metering), pricing (e.g., parking fees, 
congestion pricing, roadway tolls), real-time travel information and 
multimodal freight strategies in their SIPs. The EPA has released 
several documents that could be useful to air agencies that want to 
evaluate emissions reductions from travel efficiency strategies. These 
documents provide information on analysis methods and the potential 
effectiveness of different combinations of travel efficiency measures 
for reducing emissions. Additionally, the EPA has compiled a report 
about transportation control measures that have been implemented across 
the country for a variety of purposes, including reducing emissions 
related to criteria pollutants. All of these documents are available on 
the EPA's Office of Transportation and Air Quality Web site.\100\
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    \100\ See http://www.epa.gov/otaq/stateresources/policy/pag_transp.htm.
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F. Additional Requirements Related to Enforcement and Compliance

    CAA section 172(c)(6) requires nonattainment SIPs to ``include 
enforceable emission limitations, and such other control measures, 
means or techniques . . . as well as schedules and timetables for 
compliance, as may be necessary or appropriate to provide for 
attainment . . .'' The EPA's current guidance, ``Guidance on Preparing 
Enforceable Regulations and Compliance Programs for the 15 Percent 
Rate-of-Progress Plans (EPA-452/R-93-005, June 1993)'' \101\ is still 
relevant to rules adopted for SIPs under the 2015 ozone NAAQS and 
should be consulted for purposes of developing appropriate enforceable 
nonattainment plan provisions under CAA section 172(c)(6). The EPA is 
not proposing any additional specific regulatory provisions related to 
compliance and enforcement for implementing the 2015 ozone NAAQS.
---------------------------------------------------------------------------

    \101\ Available at: http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=00002TCM.txt.
---------------------------------------------------------------------------

G. Applicability of Proposed Rule to Tribes

    Section 301(d) of the CAA authorizes the EPA to approve eligible 
Indian tribes to implement provisions of the CAA on Indian reservations 
and other areas within the tribes' jurisdiction.\102\ The TAR (40 CFR 
part 49.1-49.11), which implements CAA section 301(d), sets forth the 
criteria and process for tribes to apply to the EPA for eligibility to 
administer CAA programs (40 CFR 49.6, 49.7). As discussed in detail in 
the proposed 2008 Ozone NAAQS SIP Requirements Rule (78 FR 34209; June 
6, 2013), tribes are not required to TIPs under the TAR. However, 
should a tribe choose to develop a TIP, this proposed rule is intended 
to serve as a guide for addressing key implementation issues for their 
area of Indian country, particularly for any areas of Indian country 
that may be designated as nonattainment areas separate from surrounding 
state areas.
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    \102\ On January 17, 2014, the United States Court of Appeals 
for the District of Columbia Circuit issued a decision vacating the 
EPA's 2011 rule titled ``Review of New Sources and Modifications in 
Indian Country'' (76 FR 38748) with respect to non-reservation areas 
of Indian country (See, Oklahoma Department of Environmental Quality 
v. EPA, 740 F.3d 185 (D.C. Cir. 2014)). Under the court's reasoning, 
with respect to CAA SIPs, a state has primary regulatory 
jurisdiction in non-reservation areas of Indian country (i.e., 
Indian allotments located outside of reservations and dependent 
Indian communities) within its geographic boundaries unless the EPA 
or a tribe has demonstrated that a tribe has jurisdiction over a 
particular area of non-reservation Indian country within the state.
---------------------------------------------------------------------------

    It is important for state and local air agencies and tribes to work 
together to coordinate planning efforts where nonattainment areas 
include both Indian country and state land. Coordinated planning in 
these areas will help ensure that the planning decisions made by the 
state and local air agencies and tribes complement each other and that 
the nonattainment area makes reasonable progress toward attainment and 
ultimately attains the 2015 ozone NAAQS. In reviewing and approving 
individual TIPs and SIPs, we will determine if together they are 
consistent with the overall air quality needs of an area.
    States have an obligation to notify other states in advance of any 
public hearing(s) on their state plans if such plans will significantly 
impact such other states. 40 CFR 51.102(d)(5). Under CAA section 301(d) 
of the CAA and the TAR, tribes may become eligible to be treated in a 
manner similar to states (TAS) for this purpose (40 CFR 49.6-49.9). 
Affected tribes with this status must also be informed of the contents 
of such state plans and given access to the documentation supporting 
these plans. In addition to this mandated process, we encourage states 
to extend the same notice to all affected tribes, regardless of their 
TAS status.
    Executive Orders and the EPA's Indian policies generally call for 
the EPA to coordinate and consult with tribes on matters that affect 
tribes. Executive Order 13175, titled, ``Consultation and Coordination 
with Indian Tribal Governments'' requires the EPA to develop a process 
to ensure ``meaningful and timely input by tribal officials in the 
development of regulatory policies that have Tribal implications.'' In 
addition, the EPA's policies include the agency's 1984 Indian Policy 
relating to Indian tribes and implementation of federal environmental 
programs, the April 10, 2009, OAQPS guidance ``Consulting with Indian 
Tribal Governments,'' and the ``EPA Policy on Consultation and 
Coordination With Indian Tribes.'' \103\
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    \103\ Tribal guidance documents are available at: http://www.epa.gov/tribal/forms/consultation-and-coordination-tribes.

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[[Page 81307]]

    Consistent with these policies, the EPA intends to coordinate and 
consult with tribes on activities potentially affecting the attainment 
and maintenance of the 2015 ozone NAAQS in Indian country, including 
our actions on SIPs. We encourage state air agencies to work with 
tribes with land that is part of the same general air quality planning 
area during the SIP development process and to coordinate with tribes 
as they develop their SIPs regardless of whether the tribe's area of 
Indian country is separately designated.

VI. Environmental Justice Considerations

    The EPA believes this action will not have disproportionately high 
and adverse human health or environmental effects on minority, low-
income, or indigenous populations because it would not negatively 
affect the level of protection provided to human health or the 
environment under the 2015 ozone NAAQS, which are at levels to protect 
sensitive populations with an adequate margin of safety.\104\ When 
promulgated, these regulations will clarify the SIP requirements and 
the NNSR permitting requirements to be met by air agencies in order to 
attain the 2015 ozone NAAQS as expeditiously as practicable. These 
requirements are designed to protect all segments of the general 
population and will not adversely affect the health or safety of 
minority, low-income or indigenous populations.
---------------------------------------------------------------------------

    \104\ The EPA conducted a regulatory impact analysis (RIA) of 
its final action establishing the 2015 ozone NAAQS. The demographic 
analysis conducted as part of the RIA found that in areas with poor 
air quality relative to the revised standards, the representation of 
minority populations was slightly greater than in the U.S. as a 
whole (see Chapter 9, section 9.10 and Appendix 9A of the RIA). 
Because the air quality in these areas does not currently meet the 
revised standards, populations in these areas would be expected to 
benefit from implementation of the strengthened standards. The RIA 
is available at https://www3.epa.gov/ttn/ecas/docs/20151001ria.pdf 
and in the RIA docket (EPA-HQ-OAR-2013-0169).
---------------------------------------------------------------------------

VII. 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 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 proposed rule have 
been submitted for approval to OMB under the PRA. The ICR document that 
the EPA prepared has been assigned the EPA ICR No. 2347.03 and OMB 
Reference No. 2060-0695. You can find a copy of the ICR in the docket 
for this rule, and it is briefly summarized here. The information 
collection requirements are not enforceable until OMB approves them.
    The EPA is proposing these implementing regulations for 2015 ozone 
NAAQS so that air agencies will know what CAA requirements apply to 
their nonattainment areas when the air agencies develop their SIPs for 
attaining and maintaining the NAAQS. The intended effect of these 
implementing regulations is to provide certainty to air agencies 
regarding their planning obligations. For purposes of analysis of the 
estimated paperwork burden, the EPA assumed 57 nonattainment 
areas,\105\ some of which must prepare an attainment demonstration as 
well as submit an RFP and RACT SIP. The attainment demonstration 
requirement would appear in 40 CFR 51.1308 which implements CAA 
subsections 172(c)(1), 182(b)(1)(A) and 182(c)(2)(B). The RFP SIP 
submission requirement would appear in 40 CFR 51.1310, and the RACT SIP 
submission requirement would appear in 40 CFR 51.1312, which implements 
CAA subsections 172(c)(1) 182(b)(2),(c),(d) and (e).
---------------------------------------------------------------------------

    \105\ The EPA developed a hypothetical list of nonattainment 
areas for estimating the burden for states to meet their 2015 ozone 
nonattainment area requirements. The hypothetical nonattainment 
areas were based on the preliminary 2013-2015 air quality data 
available. The hypothetical nonattainment areas include multiple 
counties for most areas based on the existing 2008 and 1997 8-hour 
ozone nonattainment areas, Combined Statistical Area, or Core Based 
Statistical Area boundary associated with a violating monitor. Note 
that these areas are used for analytical purposes only. Actual 
nonattainment areas and boundaries will be determined through the 
designations process.
---------------------------------------------------------------------------

    Air agencies should already have information from many emission 
sources, as facilities should have provided this information to meet 1-
hour, 1997, and 2008 ozone NAAQS SIP requirements, operating permits 
and/or emissions reporting requirements. Such information does not 
generally reveal the details of production processes. But, to the 
extent it may, CBI for the affected facilities is protected. 
Specifically, submissions of emissions and control efficiency 
information that is confidential, proprietary and trade secret is 
protected from disclosure under the requirements of subsections 503(e) 
and 114(c) of the CAA.
    The annual burden for this information collection averaged over the 
first 3 years of this ICR is estimated to be a total of 41,800 labor 
hours per year at an annual labor cost of $2.5 million (present value) 
over the 3-year period or approximately $107,000 per state for the 23 
state air agency respondents. The ICR Supporting Statement for the 2015 
8-hour Ozone NAAQS Implementation Rule EPA ICR No. 2347.03 in the 
docket provides the details for the 23 state air agencies that are 
required to provide the 66 SIP revisions for the 57 hypothetical areas 
designated nonattainment for the 2015 ozone standard. The average 
annual reporting burden is 633 hours per response, with approximately 
2.87 responses per state for 66 state responses from the state air 
agencies. There are no capital or operating and maintenance costs 
associated with the proposed rule requirements. Burden is defined at 5 
CFR 1320.3(b).
    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.
    To comment on the agency's need for this information, the accuracy 
of the provided burden estimates and any suggested methods for 
minimizing respondent burden, the EPA has established a public docket 
for this rule, which includes this ICR, under Docket ID No. EPA-HQ-OAR-
2016-0202. Commenters should submit any comments related to the ICR to 
both the EPA and OMB. See the ADDRESSES section at the beginning of 
this notice for where to submit comments to the EPA. Send comments to 
OMB at the Office of Information and Regulatory Affairs, Office of 
Management and Budget, 725 17th Street NW., Washington, DC 20503, 
Attention: Desk Office for EPA. Since OMB is required to make a 
decision concerning the ICR between 30 and 60 days after November 17, 
2016, a comment to OMB is best assured of having its full effect if OMB 
receives it by December 19, 2016. The final rule will respond to any 
OMB or public comments on the information collection requirements 
contained in this proposal.

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 this rule include state, local and 
tribal governments and none of these governments are small governments. 
Other types of small entities are not directly subject to the 
requirements of this rule because this

[[Page 81308]]

action only addresses how a SIP will provide for adequate attainment 
and maintenance of the NAAQS and meet the obligations of the CAA. 
Although some states may ultimately decide to impose economic impacts 
on small entities, that is not required by this rule and would only 
occur at the discretion of the state.

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. The action implements mandates specifically and 
explicitly set forth in the CAA without the exercise of any policy 
discretion by the EPA.

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 would not have a substantial direct effect on 
one or more Indian tribes, since no tribe has to develop a TIP under 
these regulatory revisions. 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 Tribal Air Rule establish the relationship of the federal 
government and tribes in developing plans to attain the NAAQS, 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 briefed tribal officials in developing this proposal.

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 (NTTA)

    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 does not have disproportionately 
high and adverse human health or environmental effects on minority 
populations, low-income populations and/or indigenous populations as 
specified in Executive Order 12898 (59 FR 7629, February 16, 1994). The 
documentation for this decision is contained in Section VI of this 
preamble.

VIII. Statutory Authority

    The statutory authority for this action is provided by sections 
109; 110; 172; 181 through 185B; 301(a)(1) and 501(2)(B) of the CAA, as 
amended (42 U.S.C. 7409; 42 U.S.C. 7410; 42 U.S.C. 7502; 42 U.S.C. 
7511-7511f; 42 U.S.C. 7601(a)(1); 42 U.S.C. 7661(2)(B)).

List of Subjects

40 CFR Part 50

    Environmental protection, Air pollution control, Carbon monoxide, 
Lead, Nitrogen dioxide, Ozone, Particulate matter, Sulfur oxides.

40 CFR Part 51

    Environmental protection, Air pollution control, Intergovernmental 
relations, Ozone, Particulate matter, Transportation, Volatile organic 
compounds.

    Dated: November 2, 2016.
Gina McCarthy,
Administrator.
    For the reasons stated in the preamble, Title 40, Chapter I of the 
Code of Federal Regulations is proposed to be amended as follows:

PART 50--NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY 
STANDARDS

0
1. The authority citation for part 50 continues to read as follows:

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

0
2. In Sec.  50.15, add paragraph (c) to read as follows:

Sec.  50.15  National 8-hour primary and secondary ambient air quality 
standards for ozone.

* * * * *

Proposed Regulatory Text for Option 1

    (c) The 2008 ozone NAAQS set forth in this section will remain 
applicable to all areas of the country notwithstanding the promulgation 
of 2015 ozone NAAQS under Sec.  50.19. The 2008 ozone NAAQS set forth 
in this section will no longer apply to an area 1 year after the 
effective date of the initial area designation of that area for the 
2015 ozone NAAQS pursuant to section 107 of the CAA. For purposes of 
the anti-backsliding requirements of Sec.  51.1305, Sec.  51.165 and 
Appendix S to part 51, the area designations and classifications with 
respect to the revoked 1-hour, 1997 and 2008 ozone NAAQS are codified 
in 40 CFR part 81.

Proposed Regulatory Text for Option 2

    (c) Notwithstanding the promulgation of 2015 ozone NAAQS under 
Sec.  50.19, the 2008 ozone NAAQS set forth in this section will remain 
applicable to any area of the country designated nonattainment for the 
2008 ozone NAAQS as of the date of that area's initial designation for 
the 2015 ozone NAAQS pursuant to section 107 of the CAA. For any other 
area of the country, the 2008 ozone NAAQS set forth in this section 
will no longer apply to such area 1 year after the effective date of 
the initial designation of that area for the 2015 ozone NAAQS pursuant 
to section 107 of the CAA.

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

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

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

0
4. Revise Sec.  51.1119 to read as follows:

Subpart AA--Provisions for Implementation of 8-Hour Ozone National 
Ambient Air Quality Standards

Sec.  51.1119  Applicability.

    As of revocation of the 2008 ozone NAAQS in an area, as set forth 
in Sec.  50.15(c), the provisions of Sec. Sec.  51.1100 to 51.1118 of 
subpart AA cease to apply, [Proposed Regulatory Text for Option 1: 
except for Sec.  51.1107 for the anti-backsliding purposes of Sec.  
51.1305(c)(2).]

[[Page 81309]]

0
5. Part 51 is amended by adding subpart CC to read as follows:
Subpart CC--Provisions for Implementation of the 2015 Ozone National 
Ambient Air Quality Standards
Sec.
51.1300 Definitions.
51.1301 Applicability of part 51.
51.1302 Classification and nonattainment area planning provisions.
51.1303 Application of classification and attainment date provisions 
in CAA section 181 to areas subject to Sec.  51.1302.
51.1304 [Reserved]
51.1305 Transition from the 2008 ozone NAAQS to the 2015 ozone NAAQS 
and anti-backsliding.
51.1306 Redesignation to nonattainment following initial 
designations.
51.1307 Determining eligibility for 1-year attainment date 
extensions for an 8-hour ozone NAAQS under CAA section 181(a)(5).
51.1308 Modeling and attainment demonstration requirements.
51.1309 Demonstrations that areas would have attained but for 
international emissions under CAA section 179B(b)
51.1310 Requirements for reasonable further progress (RFP).
51.1311 [Reserved]
51.1312 Requirements for reasonably available control technology 
(RACT) and reasonably available control measures (RACM).
51.1313 Section 182(f) NOX exemption provisions.
51.1314 New source review requirements.
51.1315 Emissions inventory requirements.
51.1316 Requirements for an Ozone Transport Region.
51.1317 Fee programs for Severe and Extreme nonattainment areas that 
fail to attain.
51.1318 Suspension of SIP planning requirements in nonattainment 
areas that have air quality data that meet an ozone NAAQS.
51.1319 Applicability.

Subpart CC--Provisions for Implementation of the 2015 Ozone 
National Ambient Air Quality Standards

Sec.  51.1300  Definitions.

    The following definitions apply for purposes of this subpart. Any 
term not defined herein shall have the meaning as defined in 40 CFR 
51.100.
    (a) 1-hour NAAQS means the 1-hour primary and secondary ozone 
national ambient air quality standards codified at 40 CFR 50.9.
    (b) 1997 NAAQS means the 1997 8-hour primary and secondary ozone 
national ambient air quality standards codified at 40 CFR 50.10.
    (c) 2008 NAAQS means the 2008 8-hour primary and secondary ozone 
NAAQS codified at 40 CFR 50.15.
    (d) 2015 NAAQS means the 2015 8-hour primary and secondary ozone 
NAAQS codified at 40 CFR 50.19.
    (e) 1-hour ozone design value is the 1-hour ozone concentration 
calculated according to 40 CFR part 50, appendix H and the 
interpretation methodology issued by the Administrator most recently 
before the date of the enactment of the CAA Amendments of 1990.
    (f) 8-hour ozone design value is the 8-hour ozone concentration 
calculated according to 40 CFR part 50, appendix P for the 2008 NAAQS, 
and 40 CFR part 50, appendix U for the 2015 NAAQS.
    (g) CAA means the Clean Air Act as codified at 42 U.S.C. 7401-7671q 
(2010).
    (h) Attainment area means, unless otherwise indicated, an area 
designated as either attainment, unclassifiable, or attainment/
unclassifiable.
    (i) Attainment year ozone season shall mean the ozone season 
immediately preceding a nonattainment area's maximum attainment date.
    (j) Designation for a NAAQS shall mean the effective date of the 
designation for an area for that NAAQS.
    (k) Higher classification/lower classification. For purposes of 
determining whether a classification is higher or lower, 
classifications under subpart 2 of part D of title I of the CAA are 
ranked from lowest to highest as follows: Marginal; Moderate; Serious; 
Severe-15; Severe-17; and Extreme.
    (l) Initially designated means the first designation that becomes 
effective for an area for a specific NAAQS and does not include a 
redesignation to attainment or nonattainment for that specific NAAQS.
    (m) Maintenance area means an area that was designated 
nonattainment for a specific NAAQS and was redesignated to attainment 
for that NAAQS subject to a maintenance plan as required by CAA section 
175A.
    (n) Nitrogen Oxides (NOX) means the sum of nitric oxide 
and nitrogen dioxide in the flue gas or emission point, collectively 
expressed as nitrogen dioxide.
    (o) Ozone season means for each state (or portion of a state), the 
ozone monitoring season as defined in 40 CFR part 58, appendix D, 
section 4.1(i) for that state (or portion of a state).

[Proposed Regulatory Text for Option 1:

    (p) Applicable requirements for an area for anti-backsliding 
purposes means the following requirements, to the extent such 
requirements apply to the area pursuant to its classification for 
revoked ozone NAAQS, as codified in 40 CFR part 51, on the effective 
date of the revocation of those NAAQS:
    (1) Reasonably available control technology (RACT) under CAA 
sections 172(c)(1) and 182(b)(2).
    (2) Vehicle inspection and maintenance programs (I/M) under CAA 
sections 182(b)(4) and 182(c)(3).
    (3) Major source applicability thresholds for purposes of RACT 
under CAA sections 172(c)(2), 182(b), 182(c), 182(d), and 182(e).
    (4) Reductions to achieve Reasonable Further Progress (RFP) under 
CAA sections 172(c)(2), 182(b)(1)(A), and 182(c)(2)(B) and EPA's 
implementing regulations at Sec.  51.1310.
    (5) Clean fuels fleet program under CAA section 183(c)(4).
    (6) Clean fuels for boilers under CAA section 182(e)(3).
    (7) Transportation Control Measures (TCMs) during heavy traffic 
hours as specified under CAA section 182(e)(4).
    (8) Enhanced (ambient) monitoring under CAA section 182(c)(1).
    (9) Transportation controls under CAA section 182(c)(5).
    (10) Vehicle miles traveled provisions of CAA section 182(d)(1).
    (11) NOX requirements under CAA section 182(f).
    (12) Attainment demonstration requirements under CAA sections 
172(c)(4), 182(b)(1)(A), and 182(c)(2).
    (13) Nonattainment contingency measures required under CAA sections 
172(c)(9) and 182(c)(9) for failure to attain an ozone NAAQS by the 
applicable attainment date for that NAAQS or failure to make reasonable 
further progress toward attainment of that ozone NAAQS.
    (14) Nonattainment NSR major source thresholds and offset ratios 
under CAA sections 172(a)(5) and 182(a)(2).
    (15) Penalty fee program requirements for Severe and Extreme Areas 
under CAA section 185.
    (16) Contingency measures associated with areas utilizing CAA 
section 182(e)(5).
    (17) Reasonably available control measures (RACM) requirements 
under CAA section 172(c)(1).]
    (q) CSAPR means the Cross-State Air Pollution Rule codified at 40 
CFR 52.38 and part 97.
    (r) CAIR means the Clean Air Interstate Rule codified at 40 CFR 
51.123, 52.35 and part 95.
    (s) NOX SIP Call means the rules codified at 40 CFR 51.121 and 
51.122.
    (t) Ozone transport region (OTR) means the area established by CAA 
section 184(a) or any other area established by the Administrator 
pursuant to CAA section 176A for purposes of ozone.
    (u) Reasonable further progress (RFP) means the emissions 
reductions

[[Page 81310]]

required under CAA sections 172(c)(2), 182(c)(2)(B), 182(c)(2)(C), and 
Sec.  51.1310. The EPA interprets RFP under CAA section 172(c)(2) to be 
an average 3 percent per year emissions reduction of either VOC or 
NOX.
    (v) Rate-of-progress (ROP) means the 15 percent progress reductions 
in VOC emissions over the first 6 years after the baseline year 
required under CAA section 182(b)(1).
    (w) Revocation of the 1-hour ozone NAAQS means the time at which 
the 1-hour ozone NAAQS no longer apply to an area pursuant to 40 CFR 
50.9(b). The date of revocation of the 1-hour NAAQS was June 15, 2005 
for most areas of the country.
    (x) Revocation of the 1997 ozone NAAQS means the time at which the 
1997 8-hour ozone NAAQS no longer apply to an area pursuant to 40 CFR 
50.10(c). The date of revocation of the 1997 ozone NAAQS was April 6, 
2015 for all areas of the country.
    (y) Revocation of the 2008 ozone NAAQS means the time at which the 
2008 8-hour ozone NAAQS no longer apply to an area pursuant to 40 CFR 
50.15(c).
    (z) Subpart 1 means subpart 1 of part D of title I of the CAA.
    (aa) Subpart 2 means subpart 2 of part D of title I of the CAA.
    (bb) I/M refers to the inspection and maintenance programs for in-
use vehicles required under the 1990 CAA Amendments and defined by 
subpart S of 40 CFR part 51.
    (cc) An area ``Designated nonattainment for the 1-hour ozone 
NAAQS'' means, for purposes of 40 CFR 51.1305, an area that is subject 
to applicable 1-hour ozone NAAQS anti-backsliding requirements as of 
April 6, 2015, the effective date of the revocation of the 1997 ozone 
NAAQS.
    (dd) An area ``Designated nonattainment for the 1997 8-hour ozone 
NAAQS'' means, for purposes of 40 CFR 51.1305, an area that is subject 
to applicable 1997 ozone NAAQS anti-backsliding requirements as of 
April 6, 2015, the effective date of the revocation of the 1997 ozone 
NAAQS.
    (ee) An area ``Designated nonattainment for the 2008 8-hour ozone 
NAAQS'' means, for purposes of 40 CFR 51.1305, an area that is subject 
to applicable 2008 8-hour ozone NAAQS anti-backsliding requirements as 
of the effective date of the revocation of the 2008 ozone NAAQS.
    (ff) Current ozone NAAQS means the most recently promulgated ozone 
NAAQS at the time of application of any provision of this subpart.
    (gg) Base year inventory for the nonattainment area means a 
comprehensive, accurate, current inventory of actual emissions from 
sources of VOC and NOX emitted within the boundaries of the 
nonattainment area as required by CAA section 182(a)(1).
    (hh) Ozone season day emissions means an average day's emissions 
for a typical ozone season work weekday. The state shall select, 
subject to EPA approval, the particular month(s) in the ozone season 
and the day(s) in the work week to be represented, considering the 
conditions assumed in the development of RFP plans and/or emissions 
budgets for transportation conformity.

Sec.  51.1301  Applicability of part 51.

    The provisions in subparts A-Y and AA of part 51 apply to areas for 
purposes of the 2015 ozone NAAQS to the extent they are not 
inconsistent with the provisions of this subpart.

Sec.  51.1302  Classification and nonattainment area planning 
provisions.

    An area designated nonattainment for the 2015 ozone NAAQS will be 
classified in accordance with CAA section 181, as interpreted in Sec.  
51.1303(a), and will be subject to the requirements of subpart 2 of 
part D of title I of the CAA that apply for that classification.

Sec.  51.1303  Application of classification and attainment date 
provisions in CAA section 181 to areas subject to Sec.  51.1302.

    (a) In accordance with CAA section 181(a)(1), each area designated 
nonattainment for the 2015 ozone NAAQS shall be classified by operation 
of law at the time of designation. The classification shall be based on 
the 8-hour design value for the area at the time of designation, in 
accordance with Table 1 of paragraph (a) of this section. A state may 
request a higher or lower classification as provided in paragraphs (b) 
and (c) of this section. For each area classified under this section, 
the attainment date for the 2015 NAAQS shall be as expeditious as 
practicable, but not later than the date provided in Table 1 as 
follows:

   Table 1--Classifications and Attainment Dates for 2015 8-Hour Ozone
          NAAQS (0.070 ppm) for Areas Subject to 40 CFR 51.1302
------------------------------------------------------------------------
                                                        Primary standard
                                                        attainment date
                                                        (years after the
            Area class                8-Hour design    effective date of
                                    value (ppm ozone)   designation for
                                                          2015 primary
                                                             NAAQS)
------------------------------------------------------------------------
Marginal:
    from..........................              0.071                  3
    up to *.......................              0.081
Moderate:
    from..........................              0.081                  6
    up to *.......................              0.093
Serious:
    from..........................              0.093                  9
    up to *.......................              0.105
Severe-15:
    from..........................              0.105                 15
    up to *.......................              0.111
Severe-17:
    from..........................              0.111                 17
    up to *.......................              0.163
Extreme:
    equal to or above.............              0.163                 20
------------------------------------------------------------------------
* But not including.

[[Page 81311]]

    (b) A state may request, and the Administrator must approve, a 
higher classification for an area for any reason in accordance with CAA 
section 181(b)(3).
    (c) A state may request, and the Administrator may in the 
Administrator's discretion approve, a higher or lower classification 
for an area in accordance with CAA section 181(a)(4).
    (d) The following nonattainment areas are reclassified for the 2015 
ozone NAAQS as follows: Serious--Ventura County, CA; Severe--Los 
Angeles-San Bernardino Counties (West Mojave Desert), Riverside County 
(Coachella Valley), and Sacramento Metro, CA; Extreme--Los Angeles-
South Coast Air Basin, and San Joaquin Valley, CA.

Sec.  51.1304  [Reserved]

Sec.  51.1305  Transition from the 2008 ozone NAAQS to the 2015 ozone 
NAAQS and anti-backsliding.

    (a) Requirements that continue to apply after revocation of prior 
ozone NAAQS. (1) Areas designated nonattainment for the 2015 ozone 
NAAQS and nonattainment for a prior revoked ozone NAAQS. The following 
requirements apply to an area designated nonattainment for the 2015 
ozone NAAQS and also designated nonattainment for a prior ozone NAAQS 
as of the effective date of the revocation of the respective prior 
ozone NAAQS unless the area has an approved redesignation substitute: 
The area remains subject to the obligation to adopt and implement the 
applicable requirements of Sec.  51.1300(p), for any ozone NAAQS for 
which it was designated nonattainment as of the effective date of its 
revocation, in accordance with its classification for that NAAQS as of 
the effective date of its revocation, except as provided in paragraph 
(b) of this section or if the area has an approved redesignation 
substitute.
    (2) Areas designated nonattainment for the 2015 ozone NAAQS and 
maintenance for a prior revoked ozone NAAQS. For an area designated 
nonattainment for the 2015 ozone NAAQS that was redesignated to 
attainment for a prior ozone NAAQS prior to the effective date of the 
revocation of the respective prior ozone NAAQS (hereinafter a 
``maintenance area''), the approved SIP, including the maintenance 
plan, is considered to satisfy the applicable requirements of 40 CFR 
51.1300(p) for the revoked NAAQS. The measures in the approved SIP and 
maintenance plan shall continue to be implemented in accordance with 
the terms in the approved SIP. Any measures associated with applicable 
requirements that were shifted to contingency measures prior to the 
effective date of the revocation of the prior ozone NAAQS shall remain 
in that form. After revocation of a prior NAAQS, and to the extent 
consistent with any SIP for the 2015 ozone NAAQS and with CAA sections 
110(l) and 193, the state may request approval from the EPA to shift 
obligations under the applicable requirements of Sec.  51.1300(p) to 
the SIP's list of maintenance plan contingency measures for the area.
    (3) Areas designated attainment for the 2015 ozone NAAQS and 
nonattainment for a prior revoked ozone NAAQS. For an area designated 
attainment for the 2015 ozone NAAQS, and designated nonattainment for 
the a prior ozone NAAQS as of the effective date of the revocation of 
the respective prior ozone NAAQS, the area is no longer subject to 
nonattainment NSR for the 1997 or 2008 ozone NAAQS, if applicable, and 
the state may request approval from the EPA to either remove the 
nonattainment NSR provisions from the SIP or shift them to the SIP's 
list of maintenance plan contingency measures for the area. Such 
approval must be consistent with CAA sections 110(l) and 193. If the 
area's nonattainment NSR provisions are removed from the active portion 
of the SIP for the area, the area's approved PSD SIP shall be 
considered to satisfy the state's obligations with respect to the 
area's maintenance of the 2015 ozone NAAQS pursuant to CAA section 
110(a)(1). The state may request approval from the EPA, consistent with 
CAA sections 110(l) and 193, to shift SIP measures adopted to satisfy 
other applicable requirements of Sec.  51.1300(p) to the SIP's list of 
maintenance plan contingency measures for the area.
    (4) Requirements for areas designated attainment for the 2015 ozone 
NAAQS and maintenance for a prior revoked ozone NAAQS. An area 
designated attainment for the 2015 ozone NAAQS with an approved CAA 
section 175A maintenance plan for a prior revoked ozone NAAQS is 
considered to satisfy the applicable requirements of 40 CFR 51.1300(p) 
through implementation of the SIP and maintenance plan provisions for 
the area. After revocation of a prior NAAQS, and to the extent 
consistent with CAA sections 110(l) and 193, the state may request 
approval from the EPA to shift obligations under the applicable 
requirements of 40 CFR 51.1300(p) to the list of maintenance plan 
contingency measures for the area.
    For an area that is initially designated attainment for the 2015 
ozone NAAQS and which has been redesignated to attainment for a prior 
revoked ozone NAAQS with an approved CAA section 175A maintenance plan 
and an approved PSD SIP, the area's approved maintenance plan and the 
state's approved PSD SIP for the area are considered to satisfy the 
state's obligations with respect to the area's maintenance of the 2015 
ozone NAAQS pursuant to CAA section 110(a)(1).
    (b) Effect of Redesignation or Redesignation Substitute. (1) An 
area remains subject to the anti-backsliding obligations for a revoked 
NAAQS under paragraphs (a)(1) and (a)(2) of this section until either: 
(i) EPA approves a redesignation to attainment for the area for the 
2015 ozone NAAQS, in which case regulatory anti-backsliding 
requirements for the 1997 and 2008 ozone standards, if applicable, are 
satisfied; or (ii) EPA approves a demonstration for the area in a 
redesignation substitute procedure for a revoked NAAQS. Under this 
redesignation substitute procedure for a revoked NAAQS, and for this 
limited anti-backsliding purpose, the demonstration must show that the 
area has attained that revoked NAAQS due to permanent and enforceable 
emission reductions and that the area will maintain that revoked NAAQS 
for 10 years from the date of EPA's approval of this showing.
    (2) If EPA, after notice-and-comment rulemaking, approves a 
redesignation to attainment, the state may request approval from the 
EPA to either remove provisions for nonattainment NSR from the SIP for 
the 1997 and 2008 ozone standards, subject to the requirements of CAA 
sections 110(l) and 193, or shift them to the SIP's list of maintenance 
plan contingency measures for the area.
    (3) If the EPA, after notice-and-comment rulemaking, approves a 
redesignation to attainment, the state may request approval from the 
EPA to shift other anti-backsliding obligations for the 1997 and 2008 
ozone standards to contingency measures, provided that such action is 
consistent with CAA sections 110(l) and 193.
    (4) If EPA, after notice and comment rulemaking, approves a 
redesignation substitute for a revoked NAAQS, the state may request 
approval from the EPA to either remove provisions for nonattainment NSR 
for that revoked NAAQS from the SIP, or shift them to the SIP's list of 
maintenance plan contingency measures for the area.
    (5) If EPA, after notice and comment rulemaking, approves a 
redesignation substitute for a revoked NAAQS, the state may request 
approval from the EPA to shift other anti-backsliding obligations for 
that revoked NAAQS to

[[Page 81312]]

contingency measures provided that such action is consistent with CAA 
sections 110(l) and 193.
    (6) Areas that are designated nonattainment for the 2008 ozone 
NAAQS at the time of designation for the 2015 ozone NAAQS may be 
redesignated to attainment prior to the effective date of revocation of 
the 2008 ozone NAAQS.
    (c) Portions of an area designated nonattainment or attainment for 
the 2015 ozone NAAQS that remain subject to the obligations identified 
in paragraph (a) of this section. Only that portion of the designated 
nonattainment or attainment area for the 2015 ozone NAAQS that was 
required to adopt the applicable requirements in Sec.  51.1300(p) for 
purposes of a prior revoked ozone NAAQS is subject to the obligations 
identified in paragraph (a) of this section. Subpart C of 40 CFR part 
81 identifies the areas designated nonattainment and associated area 
boundaries for prior ozone NAAQS as of the effective date of the 
revocation of the prior NAAQS.
    (d) Obligations under a prior ozone NAAQS that no longer apply 
after revocation of the prior ozone NAAQS. (1) Second 10-year 
maintenance plans. As of the effective date of the revocation of a 
prior ozone NAAQS, an area with an approved maintenance plan for the 
respective prior ozone NAAQS under CAA section 175A is not required to 
submit a corresponding second 10-year maintenance plan 8 years after 
approval of the initial maintenance plan for that prior ozone NAAQS.
    (2) Determinations of failure to attain a prior revoked ozone 
NAAQS. (i) As of the effective date of the revocation of a prior ozone 
NAAQS, the EPA is no longer obligated to determine pursuant to CAA 
section 181(b)(2) or section 179(c) whether an area attained the 
respective prior ozone NAAQS by that area's attainment date for that 
prior ozone NAAQS.
    (ii) As of the effective date of the revocation of a prior ozone 
NAAQS, the EPA is no longer obligated to reclassify an area to a higher 
classification for the respective prior ozone NAAQS based upon a 
determination that the area failed to attain that prior ozone NAAQS by 
the area's attainment date for that prior ozone NAAQS.
    (iii) For a prior revoked ozone NAAQS, the EPA is required to 
determine whether an area attained the prior ozone NAAQS by the area's 
attainment date solely for anti-backsliding purposes to address an 
applicable requirement for nonattainment contingency measures and CAA 
section 185 fee programs. In making such a determination, the EPA may 
consider and apply the provisions of CAA section 181(a)(5) and former 
40 CFR 51.907 and 51.1107 in interpreting whether a 1-year extension of 
the attainment date is applicable.
    (e) Continued applicability of the Federal Implementation Plan 
(FIP) and SIP requirements pertaining to interstate transport under CAA 
section 110(a)(2)(D)(i) and (ii) after revocation of prior ozone NAAQS. 
All control requirements associated with a FIP or approved SIP in 
effect for an area as of the effective date of the revocation of a 
prior ozone NAAQS, such as the NOX SIP Call, the CAIR, or 
the CSAPR shall continue to apply after revocation of the prior ozone 
NAAQS. Control requirements approved into the SIP pursuant to 
obligations arising from CAA section 110(a)(2)(D)(i) and (ii), 
including [NOTE: Update listing as necessary to reflect CSAPR update 
rule due summer 2016] 40 CFR 51.121, 51.122, 51.123 and 51.124, may be 
modified by the state only if the requirements of Sec. Sec.  51.121, 
51.122, 51.123 and 51.124, including statewide NOX emission 
budgets continue to be in effect. Any such modification must meet the 
requirements of CAA section 110(l).
    (f) New source review. An area designated nonattainment for the 
2015 ozone NAAQS and designated nonattainment for a prior revoked ozone 
NAAQS remains subject to the obligation to adopt and implement the 
major source threshold and offset requirements for nonattainment NSR 
that apply or applied to the area pursuant to CAA sections 172(c)(5), 
173 and 182 based on the highest of: (i) The area's classification 
under CAA section 181(a)(1) for the 1-hour NAAQS as of the effective 
date of revocation of the 1-hour ozone NAAQS; (ii) the area's 
classification under 40 CFR 51.903 for the 1997 ozone NAAQS as of April 
6, 2015, which is the effective date of revocation of the 1997 ozone 
NAAQS; (iii) the area's classification under 40 CFR 51.1103 for the 
2008 ozone NAAQS as of the date a permit is issued or as of the 
effective date of revocation of the 2008 ozone NAAQS for that area, 
whichever is earlier; and (iv) the area's classification under Sec.  
51.1303 for the 2015 ozone NAAQS. Upon the approval of the EPA of 
removal of nonattainment NSR obligations for a revoked NAAQS under 
Sec.  51.1305(b), the state remains subject to the obligation to adopt 
and implement the major source threshold and offset requirements for 
nonattainment NSR that apply or applied to the area for the remaining 
applicable NAAQS consistent with this paragraph.

Sec.  51.1306  Redesignation to nonattainment following initial 
designations.

    For any area that is initially designated attainment for the 2015 
ozone NAAQS and that is subsequently redesignated to nonattainment for 
the 2015 ozone NAAQS, any absolute, fixed date applicable in connection 
with the requirements of this part other than an attainment date is 
extended by a period of time equal to the length of time between the 
effective date of the initial designation for the 2015 ozone NAAQS and 
the effective date of redesignation, except as otherwise provided in 
this subpart. The maximum attainment date for a redesignated area would 
be based on the area's classification, consistent with Table 1 in Sec.  
51.1303.

Sec.  51.1307  Determining eligibility for 1-year attainment date 
extensions for an 8-hour ozone NAAQS under CAA section 181(a)(5).

    (a) A nonattainment area will meet the requirement of CAA section 
181(a)(5)(B) pertaining to 1-year extensions of the attainment date if:
    (1) For the first 1-year extension, the area's 4th highest daily 
maximum 8-hour average in the attainment year is no greater than the 
level of that NAAQS.
    (2) For the second 1-year extension, the area's 4th highest daily 
maximum 8-hour value, averaged over both the original attainment year 
and the first extension year, is no greater than the level of that 
NAAQS.
    (b) For purposes of paragraph (a)(1) of this section, the area's 
4th highest daily maximum 8-hour average for a year shall be from the 
monitor with the highest 4th highest daily maximum 8-hour average for 
that year of all the monitors that represent that area.
    (c) For purposes of paragraph (a)(2) of this section, the area's 
4th highest daily maximum 8-hour value, averaged over both the original 
attainment year and the first extension year, shall be from the monitor 
in each year with the highest 4th highest daily maximum 8-hour average 
of all monitors that represent that area.

Sec.  51.1308  Modeling and attainment demonstration requirements.

    (a) An area classified Moderate under Sec.  51.1303(a) shall submit 
an attainment demonstration that provides for such specific reductions 
in emissions of VOCs and NOX as necessary to attain the 
primary NAAQS by the applicable attainment date, and such demonstration 
is due no later than 36 months after the effective date of the area's 
designation for the 2015 ozone NAAQS.
    (b) An area classified Serious or higher under Sec.  51.1303(a) 
shall be

[[Page 81313]]

subject to the attainment demonstration requirement applicable for that 
classification under CAA section 182(c), and such demonstration is due 
no later than 48 months after the effective date of the area's 
designation for the 2015 ozone NAAQS.
    (c) Attainment demonstration criteria. An attainment demonstration 
due pursuant to paragraph (a) or (b) of this section must meet the 
requirements of Appendix W of this part and shall include inventory 
data, modeling results, and emission reduction analyses on which the 
state has based its projected attainment date; the adequacy of an 
attainment demonstration shall be demonstrated by means of a 
photochemical grid model or any other analytical method determined by 
the Administrator, in the Administrator's discretion, to be at least as 
effective.
    (d) Implementation of control measures. For each nonattainment 
area, the state must provide for implementation of all control measures 
needed for attainment as expeditiously as practicable. All control 
measures in the attainment plan and demonstration must be implemented 
no later than the beginning of the attainment year ozone season, 
notwithstanding any alternate RACT and/or RACM implementation deadline 
requirements in Sec.  51.1312.

Sec.  51.1309  Demonstrations that areas would have attained but for 
international emissions under CAA section 179B(b).

    For purposes of CAA section 179B(b), 42 U.S.C. 7509a(b), in order 
to establish to the satisfaction of the Administrator that, with 
respect to an ozone nonattainment area classified as Marginal in such 
State, such State would have attained the national ambient air quality 
standard for ozone by the applicable attainment date, but for emissions 
emanating from outside the United States, a State must demonstrate that 
all reasonably available control measures have been implemented in the 
nonattainment area in accordance with CAA section 172(c)(1), 42 U.S.C. 
7502(c)(1).

Sec.  51.1310  Requirements for reasonable further progress (RFP).

    (a) RFP for nonattainment areas classified pursuant to Sec.  
51.1303. The RFP requirements specified in CAA section 182 for that 
area's classification shall apply.
    (1) Submission deadline. For each area classified Moderate or 
higher pursuant to Sec.  51.1303, the state shall submit a SIP revision 
no later than 36 months after the effective date of designation as 
nonattainment for the 2015 ozone NAAQS that provides for RFP as 
described in paragraphs (a)(2) through (4) of this section.
    (2) RFP requirements for areas with an approved prior ozone NAAQS 
15 percent VOC ROP plan. An area classified Moderate or higher that has 
the same boundaries as an area, or is entirely composed of several 
areas or portions of areas, for which EPA fully approved a 15 percent 
plan for a prior ozone NAAQS is considered to have met the requirements 
of CAA section 182(b)(1) for the 2015 ozone NAAQS and instead:
    (i) If classified Moderate or higher, the area is subject to the 
RFP requirements under CAA section 172(c)(2) and shall submit a SIP 
revision that:
    (A) Provides for a 15 percent emission reduction from the baseline 
year within 6 years after the baseline year;
    (B) Provides for an additional emissions reduction of 3 percent per 
year from the end of the first 6-year period after the baseline year up 
to the beginning of the attainment year if a baseline year earlier than 
2017 is used; and
    (C) Relies on either NOX or VOC emissions reductions (or 
a combination) to meet the requirements of paragraphs (a)(2)(i)(A) and 
(B) of this section. Use of NOX emissions reductions must 
meet the criteria in CAA section 182(c)(2)(C).
    (ii) If classified Serious or higher, the area is also subject to 
RFP under CAA section 182(c)(2)(B) and shall submit a SIP revision no 
later than 48 months after the effective date of designation providing 
for an average emissions reduction of 3 percent per year:
    (A) For all remaining 3-year periods after the first 6-year period 
after the baseline year until the year of the area's attainment date; 
and
    (B) That relies on either NOX or VOC emissions 
reductions (or a combination) to meet the requirements of (a)(2)(ii)(A) 
and (B). Use of NOX emissions reductions must meet the 
criteria in CAA section 182(c)(2)(C).
    (3) RFP requirements for areas for which an approved 15 percent VOC 
ROP plan for a prior ozone NAAQS exists for only a portion of the area. 
An area that contains one or more portions for which EPA fully approved 
a 15 percent VOC ROP plan for a prior ozone NAAQS (as well as areas for 
which EPA has not fully approved a 15 percent plan for a prior ozone 
NAAQS) shall meet the requirements of either paragraph (a)(3)(i) or 
(ii) of this section.
    (i) The state shall not distinguish between the portion of the area 
with a previously approved 15 percent ROP plan and the portion of the 
area without such a plan, and shall meet the requirements of paragraph 
(a)(4) of this section for the entire nonattainment area.
    (ii) The state shall treat the area as two parts, each with a 
separate RFP target as follows:
    (A) For the portion of the area without an approved 15 percent VOC 
ROP plan for a prior ozone NAAQS, the state shall submit a SIP revision 
as required under paragraph (a)(4) of this section.
    (B) For the portion of the area with an approved 15 percent VOC ROP 
plan for a prior ozone NAAQS, the state shall submit a SIP as required 
under paragraph (a)(2) of this section.
    (4) ROP Requirements for areas without an approved prior ozone 
NAAQS 15 percent VOC ROP plan.
    (i) For each area, the state shall submit a SIP revision consistent 
with CAA section 182(b)(1). The 6-year period referenced in CAA section 
182(b)(1) shall begin January 1 of the year following the year used for 
the baseline emissions inventory.
    (ii) For Moderate areas, the plan must provide for an additional 3 
percent per year reduction from the end of the first 6-year period 
after the baseline year up to the beginning of the attainment year if a 
baseline year other than the most recent triennial inventory year is 
selected under paragraph (b) of this section.
    (iii) For each area classified Serious or higher, the state shall 
submit a SIP revision consistent with CAA section 182(c)(2)(B). The 
final increment of progress must be achieved no later than the 
attainment date for the area.
    (5) Creditability of emission control measures for RFP plans. 
Except as specifically provided in CAA section 182(b)(1)(C) and (D), 
CAA section 182(c)(2)(B), and 40 CFR 51.1310(a)(6), all emission 
reductions from SIP-approved or federally promulgated measures that 
occur after the baseline emissions inventory year are creditable for 
purposes of the RFP requirements in this section, provided the 
reductions meet the requirements for creditability, including the need 
to be enforceable, permanent, quantifiable, and surplus.
    (6) Creditability of out-of-area emissions reductions. For purposes 
of meeting the RFP requirements in Sec.  51.1310, in addition to the 
restrictions on the creditability of emission control measures listed 
in Sec.  51.1310(a)(5), creditable emission reductions for fixed 
percentage reduction RFP must be obtained from emissions sources 
located within the nonattainment area.
    (7) Calculation of non-creditable emissions reductions. The 
following four categories of control measures listed in CAA section 
182(b)(1)(D) are no longer required to be calculated for

[[Page 81314]]

exclusion in RFP analyses because the Administrator has determined that 
due to the passage of time the effect of these exclusions would be de 
minimis: (i) Measures related to motor vehicle exhaust or evaporative 
emissions promulgated by January 1, 1990; (ii) regulations concerning 
Reid vapor pressure promulgated by November 15, 1990; (iii) measures to 
correct previous RACT requirements; and (iv) measures required to 
correct previous I/M programs.
    (b) Baseline emissions inventory for RFP plans. For the RFP plans 
required under this section, at the time of designation as 
nonattainment for an ozone NAAQS the baseline emissions inventory shall 
be the emissions inventory for the most recent calendar year for which 
a complete triennial inventory is required to be submitted to EPA under 
the provisions of subpart A of this part. States may use an alternative 
baseline emissions inventory provided that the year selected is between 
the year of designation as nonattainment for that NAAQS and the year 
that NAAQS was promulgated. All states associated with a multi-state 
nonattainment area must consult and agree on a single alternative 
baseline year. The emissions values included in the inventory required 
by this section shall be actual ozone season day emissions as defined 
by Sec.  51.1300(ee).
    (c) Milestones. (1) Applicable milestones. Consistent with CAA 
section 182(g)(1) for each area classified Serious or higher, the state 
shall determine at specified intervals whether each area has achieved 
the reduction in emissions required under paragraphs (a)(2) through (4) 
of this section. The initial determination shall occur 6 years after 
the baseline year, and at intervals of every 3 years thereafter. The 
reduction in emissions required by the end of each interval shall be 
the applicable milestone.
    (2) Milestone compliance demonstrations. For each area subject to 
the milestone requirements under paragraph (c)(1) of this section, not 
later than 90 days after the date on which an applicable milestone 
occurs (not including an attainment date on which a milestone occurs in 
cases where the ozone standards have been attained), each state in 
which all or part of such area is located shall submit to the 
Administrator a demonstration that the milestone has been met. The 
demonstration under this paragraph must provide for objective 
evaluation of reasonable further progress toward timely attainment of 
the ozone NAAQS in the area, and may take the form of:
    (i) Such information and analysis as needed to quantify the actual 
reduction in emissions achieved in the time interval preceding the 
applicable milestone; or
    (ii) Such information and analysis as needed to demonstrate 
progress achieved in implementing the approved SIP control measures, 
including RACM and RACT, corresponding with the reduction in emissions 
achieved in the time interval preceding the applicable milestone.

Sec.  51.1311  [Reserved]

Sec.  51.1312   Requirements for reasonably available control 
technology (RACT) and reasonably available control measures (RACM).

    (a) RACT requirement for areas classified pursuant to Sec.  
51.1303. (1) For each nonattainment area classified Moderate or higher, 
the state shall submit a SIP revision that meets the VOC and 
NOX RACT requirements in CAA sections 182(b)(2) and 182(f).
    (2) SIP submission deadline. (i) For a RACT SIP required pursuant 
to initial area designations, the state shall submit the RACT SIP for 
each area no later than 24 months after the effective date of 
designation for a specific ozone NAAQS.
    (ii) For a RACT SIP required pursuant to reclassification, the SIP 
revision deadline is either 24 months from the effective date of 
reclassification, or the deadline established by the Administrator in 
the reclassification action.
    (iii) For a RACT SIP required pursuant to the issuance of a new 
Control Techniques Guideline (CTG) under CAA section 183, the SIP 
revision deadline is either 24 months from the date of CTG issuance, or 
the deadline established by the Administrator in the action issuing the 
CTG.
    (3) RACT implementation deadline. (i) For RACT required pursuant to 
initial area designations, the state shall provide for implementation 
of such RACT as expeditiously as practicable, but no later than January 
1 of the 5th year after the effective date of designation.
    (ii) For RACT required pursuant to reclassification, the state 
shall provide for implementation of such RACT as expeditiously as 
practicable, but either no later than January 1 of the 3rd year after 
the associated SIP revision submission deadline or the deadline 
established by the Administrator in the final action issuing the area 
reclassification.
    (iii) For RACT required pursuant to issuance of a new CTG under CAA 
section 183, the state shall provide for implementation of such RACT as 
expeditiously as practicable, but either no later than January 1 of the 
3rd year after the associated SIP submission deadline or the deadline 
established by the Administrator in the final action issuing the CTG.
    (b) Determination of major stationary sources for applicability of 
RACT provisions. The amount of VOC and NOX emissions are to 
be considered separately for purposes of determining whether a source 
is a major stationary source as defined in CAA section 302.
    (c) Reasonably Available Control Measures (RACM) requirements. For 
each nonattainment area required to submit an attainment demonstration 
under Sec.  51.1308(a) and (b), the state shall submit with the 
attainment demonstration a SIP revision demonstrating that it has 
adopted all RACM necessary to demonstrate attainment as expeditiously 
as practicable and to meet any RFP requirements. The SIP revision shall 
include, as applicable, other control measures on sources of emissions 
of ozone precursors located outside the nonattainment area or portion 
thereof, located within the state if doing so is necessary to provide 
for attainment of the applicable ozone NAAQS in such area by the 
applicable attainment date.

Sec.  51.1313  Section 182(f) NOX exemption provisions.

    (a) A person or a state may petition the Administrator for an 
exemption from NOX obligations under CAA section 182(f) for 
any area designated nonattainment for a specific ozone NAAQS and for 
any area in a CAA section 184 ozone transport region.
    (b) The petition must contain adequate documentation that the 
criteria in CAA section 182(f) are met.
    (c) A CAA section 182(f) NOX exemption granted for a 
prior revoked ozone NAAQS does not relieve the area from any 
NOX obligations under CAA section 182(f) for a current ozone 
NAAQS.

Sec.  51.1314  New source review requirements.

    The requirements for nonattainment NSR for the ozone NAAQS are 
located in Sec.  51.165. For each nonattainment area, the state shall 
submit a nonattainment NSR plan or plan revision for a specific ozone 
NAAQS no later than 36 months after the effective date of the area's 
designation of nonattainment or redesignation to nonattainment for that 
ozone NAAQS.

Sec.  51.1315  Emissions inventory requirements.

    (a) For each nonattainment area, the state shall submit a base year 
inventory

[[Page 81315]]

as defined by Sec.  51.1300(dd) to meet the emissions inventory 
requirement of CAA section 182(a)(1). This inventory shall be submitted 
no later than 24 months after the effective date of designation. The 
inventory year shall be selected consistent with the baseline year for 
the RFP plan as required by Sec.  51.1310(b).
    (b) For each nonattainment area, the state shall submit a periodic 
emission inventory of emissions sources in the area to meet the 
requirement in CAA section 182(a)(3)(A). With the exception of the 
inventory year and timing of submittal, this inventory shall be 
consistent with the requirements of paragraph (a) of this section. Each 
periodic inventory shall be submitted no later than the end of each 3-
year period after the required submission of the base year inventory 
for the nonattainment area. This requirement shall apply until the area 
is redesignated to attainment.
    (c) The emissions values included in the inventories required by 
paragraphs (a) and (b) of this section shall be actual ozone season day 
emissions as defined by Sec.  51.1300(ee).
    (d) In the inventories required by paragraphs (a) and (b) of this 
section, state shall report emissions from point sources according to 
the point source emissions thresholds of the Air Emissions Reporting 
Requirements (AERR), 40 CFR part 51, subpart A.
    (e) The data elements in the emissions inventories required by 
paragraphs (a) and (b) of this section shall be consistent with the 
detail required by 40 CFR part 51, subpart A. Since only emissions 
within the boundaries of the nonattainment area shall be included as 
defined by Sec.  51.1300(ee), this requirement shall apply to the 
emissions inventories required in this section instead of any total 
county requirements contained in 40 CFR part 51, subpart A.

Sec.  51.1316  Requirements for an Ozone Transport Region.

    (a) In general. CAA sections 176A and 184 apply for purposes of the 
2015 ozone NAAQS.
    (b) RACT requirements for certain portions of an Ozone Transport 
Region. (1) The state shall submit a SIP revision that meets the RACT 
requirements of CAA section 184(b) for all portions of the state 
located in an ozone transport region.
    (2) SIP submission deadline. (i) For a RACT SIP required pursuant 
to initial area designations, the state shall submit the RACT SIP 
revision no later than 24 months after the effective date of 
designation for a specific ozone NAAQS.
    (ii) For a RACT SIP required pursuant to reclassification, the SIP 
revision deadline is 24 months from the effective date of 
reclassification, or the Administrator will establish the SIP revision 
submission deadline in the reclassification action.
    (iii) For a RACT SIP required pursuant to the issuance of a new 
control techniques guideline (CTG) under CAA section 183, the SIP 
revision deadline is 24 months from the date of CTG issuance, or the 
Administrator will establish the SIP revision submission deadline in 
the action issuing the CTG.
    (3) RACT implementation deadline. (i) For RACT required pursuant to 
initial area designations, the state shall provide for implementation 
of RACT as expeditiously as practicable, but no later than January 1 of 
the 5th year after the effective date of designation.
    (ii) For RACT required pursuant to reclassification, the state 
shall provide for implementation of such RACT as expeditiously as 
practicable, but either no later than January 1 of the 3rd year after 
the associated SIP revision submission deadline or no later than a 
superseding deadline established by the Administrator in the final 
action issuing the area reclassification.
    (iii) For RACT required pursuant to issuance of a new CTG under CAA 
section 183, the state shall provide for implementation of such RACT as 
expeditiously as practicable, but either no later than January 1 of the 
3rd year after the associated SIP submission deadline or no later than 
a superseding deadline established by the Administrator in the final 
action issuing the CTG.

Sec.  51.1317  Fee programs for Severe and Extreme nonattainment areas 
that fail to attain.

    For each area classified Severe or Extreme for a specific ozone 
NAAQS, the state shall submit a SIP revision within 10 years of the 
effective date of designation for that ozone NAAQS that meets the 
requirements of CAA section 185.

Sec.  51.1318  Suspension of SIP planning requirements in nonattainment 
areas that have air quality data that meet an ozone NAAQS.

    Upon a determination by EPA that an area designated nonattainment 
for a specific ozone NAAQS has attained that NAAQS, the requirements 
for such area to submit attainment demonstrations and associated 
reasonably available control measures, reasonable further progress 
plans, contingency measures for failure to attain or make reasonable 
progress and other planning SIPs related to attainment of the ozone 
NAAQS for which the determination has been made, shall be suspended 
until such time as: The area is redesignated to attainment for that 
NAAQS or a redesignation substitute is approved as appropriate, at 
which time the requirements no longer apply; or EPA determines that the 
area has violated that NAAQS, at which time the area is again required 
to submit such plans.

Sec.  51.1319  Applicability.

    As of revocation of the 2008 ozone NAAQS, as set forth in Sec.  
50.15(c), the provisions of Subpart CC shall replace the provisions of 
subpart AA, Sec. Sec.  51.1100 to 51.1118, which cease to apply except 
for Sec.  51.1107 for the anti-backsliding purposes of Sec.  
51.1305(d)(2). See Subpart AA Sec.  51.1119.
0
6. In Appendix S to part 51, revise paragraphs IV.G.5. Introductory, 
(i) and section VII to read as follows:

Appendix S to Part 51--Emission Offset Interpretative Ruling

* * * * *

IV. * * *

G. * * *

* * * * *
    5. Interpollutant offsetting, or interpollutant trading or 
interprecursor trading or interprecursor offset substitution. In 
meeting the emissions offset requirements of paragraph IV.A, 
Condition 3 of this Ruling, the emissions offsets obtained shall be 
for the same regulated nonattainment NSR pollutant unless 
interpollutant offsetting, interpollutant trading, interprecursor 
trading or interprecursor offset substitution is permitted for a 
particular pollutant as specified in this paragraph IV.G.5 and the 
reviewing authority chooses to review such trading on a case by case 
basis as described in this section.
    (i) The offset requirements of paragraph IV.A, Condition 3 of 
this Ruling for emissions of the ozone precursors NOX and 
VOC may be satisfied by offsetting reductions of emissions of either 
of those precursors, if all other requirements contained in this 
Ruling for such offsets are also satisfied. Such precursor 
substitutions shall be made on a case-by-case basis, subject to the 
approval of the reviewing authority and the Administrator, with the 
permit applicant submitting the following information to the 
reviewing authority:
    (a) A description of the air quality model(s) used to establish 
the appropriate ratio for the precursor substitution;
    (b) a proposed ratio for the precursor substitution and 
accompanying calculations;
    (c) a demonstration substantiating that the ratio achieves an 
equivalent or greater air quality benefit for ozone in the 
nonattainment area.
    (ii) * * *
* * * * *

[[Page 81316]]

VII. Anti-Backsliding Measures for Revoked Ozone NAAQS

    Nonattainment area new source review obligations for prior ozone 
NAAQS.
    A. Except as provided in paragraph VII.B of this Ruling, an area 
designated nonattainment for the 2015 ozone NAAQS and designated 
nonattainment for a prior ozone NAAQS, as of the effective date of 
the revocation of the respective prior ozone NAAQS, remains subject 
to the obligation to adopt and implement the major source threshold 
and offset ratio requirements for nonattainment NSR that apply or 
applied to the area pursuant to sections 172(c)(5), 173 and 182 of 
the CAA based on the highest of: (i) The area's classification under 
section 181(a)(1) of the CAA for the 1-hour ozone NAAQS as of the 
effective date of revocation of that NAAQS; (ii) the area's 
classification under Sec.  51.903 for the 1997 ozone NAAQS as of the 
effective date of revocation of the 1997 ozone NAAQS; (iii) the 
area's classification under Sec.  51.1103 for the 2008 ozone NAAQS 
as of the date a permit is issued or as of the effective date of 
revocation of the 2008 ozone NAAQS, whichever is earlier; and (iv) 
the area's classification under Sec.  51.1303 for the 2015 ozone 
NAAQS.
    B.1. An area remains subject to the obligations for a revoked 
NAAQS under paragraph VII.A of this Ruling until either: (i) The 
area is redesignated to attainment for the 2015 ozone NAAQS, in 
which case regulatory anti-backsliding requirements related to the 
1997 and 2008 ozone standards are satisfied; or (ii) the EPA 
approves a demonstration for the area in a redesignation substitute 
procedure for a revoked NAAQS per the provisions of Sec.  
51.1305(b). Under this redesignation substitute procedure for a 
revoked NAAQS, and for this limited anti-backsliding purpose, the 
demonstration must show that the area has attained that revoked 
NAAQS due to permanent and enforceable emission reductions and that 
the area will maintain that revoked NAAQS for 10 years from the date 
of EPA's approval of this showing.
    2. Effect of redesignation to attainment for 2015 ozone NAAQS or 
approval of a redesignation substitute for a revoked ozone NAAQS. 
After redesignation to attainment for the 2015 ozone NAAQS, the 
state may request that provisions for nonattainment NSR for the 1997 
and 2008 ozone standards, if applicable, be removed from the SIP, 
subject to the requirements of CAA sections 110(l) and 193. After 
EPA approval of a redesignation substitute for a revoked NAAQS under 
the provisions of Sec.  51.1305(b), the state may request that 
provisions for nonattainment NSR for that revoked NAAQS be removed 
from the SIP, subject to the requirements of CAA sections 110(l) and 
193. Upon removal of nonattainment NSR provisions for a revoked 
NAAQS, the state remains subject to the obligation to adopt and 
implement the major source threshold and offset ratio requirements 
for nonattainment NSR that apply or applied to the area for the 
remaining applicable NAAQS consistent with paragraph VII.A of this 
Ruling.
* * * * *
0
7. In Sec.  51.165, revise paragraphs (a)(11)(i) and (12) to read as 
follows:

Sec.  51.165  Permit requirements.

    (a) * * *
    (11) * * *
    (i) The plan may allow the offset requirement in paragraph (a)(3) 
of this section for emissions of the ozone precursors NOX 
and VOC to be satisfied, where appropriate, by offsetting reductions of 
emissions of either of those precursors, if all other requirements 
contained in this section for such offsets are also satisfied.
    (A) The plan shall indicate whether such precursor substitutions 
for ozone precursors are to be based on a default ratio for the 
applicable ozone nonattainment area, case-by-case ratios established 
for individual permits, or a combination of these approaches whereupon 
a permit applicant may propose a case-by-case permit-specific ratio in 
lieu of the default ratio for a particular ozone nonattainment area.
    (B) The plan shall include any default ratio for precursor 
substitutions for ozone and shall be accompanied by a description of 
the air quality model(s) used and the technical demonstration 
substantiating the equivalent or greater air quality benefit for ozone 
in the nonattainment area. Any default ratio for precursor 
substitutions for ozone shall be subject to the approval of the 
Administrator.
    (C) The plan shall provide that for any case-by-case ratios used 
for individual permit, the ratio shall be approved by the reviewing 
authority and the Administrator, and should require that the permit 
applicant submit information to the reviewing authority, including the 
proposed ratio for the precursor substitution for ozone, a description 
of the air quality model(s) used, and the technical demonstration 
substantiating the equivalent or greater air quality benefit for ozone 
in the nonattainment area.
    (ii) The plan may allow the offset requirements in paragraph (a)(3) 
of this section for direct PM2.5 emissions or emissions of 
precursors of PM2.5 to be satisfied by offsetting reductions 
in direct PM2.5 emissions or emissions of any 
PM2.5 precursor identified under paragraph (a)(1)(xxxvii)(C) 
of this section if such offsets comply with the interprecursor trading 
hierarchy and ratio established in the approved plan for a particular 
nonattainment area.
    (12) The plan shall require that in any area designated 
nonattainment for the 2015 ozone NAAQS and designated nonattainment for 
the 2008 ozone NAAQS as of the effective date of revocation of the 2008 
ozone NAAQS, the requirements of this section applicable to major 
stationary sources and major modifications of ozone shall include the 
anti-backsliding requirements contained at Sec.  51.1305.
* * * * *

Appendix A to Subpart A of Part 51--Tables

0
8. In Appendix A to subpart A of part 51: Revise table 1 to read as 
follows:

 Table 1 to Appendix A of Subpart A--Emission Thresholds \1\ by Pollutant for Treatment as Point Source Under 40
                                                    CFR 51.30
----------------------------------------------------------------------------------------------------------------
                                              Every-year                            Triennial
              Pollutant               --------------------------------------------------------------------------
                                         Type A sources \ 2\         Type B sources          NAA sources \3\
----------------------------------------------------------------------------------------------------------------
(1) SO2..............................  >=2500.................  >=100..................  >=100.
                                                                                         PM2.5 (Serious) >=70.
(2) VOC..............................  >=250..................  >=100..................  >=100.
                                                                within OTR \4\ >=50....  within OTR >=50.
                                                                                         O3 (Serious) >=50.
                                                                                         O3 (Severe) >=25.
                                                                                         O3 (Extreme) >=10.
                                                                                         PM2.5 (Serious) >=70.
(3) NOX..............................  >=2500.................  >=100..................  >=100.
                                                                                         O3 (Moderate within
                                                                                          OTR) >=50.
                                                                                         O3 (Serious) >=50.
                                                                                         O3 (Severe) >=25.
                                                                                         O3 (Extreme) >=10.

[[Page 81317]]

 
                                                                                         PM2.5 (Serious) >=70.
(4) CO...............................  >=2500.................  >=1000.................  >=1000.
                                                                                         CO (all areas) >=100.
(5) Lead.............................                           >=0.5 (actual).........  >=0.5 (actual).
(6) Primary PM10.....................  >=250..................  >=100..................  >=100.
                                                                                         PM10 (Serious) >=70.
(7) Primary PM2.5....................  >=250..................  >=100..................  >=100.
                                                                                         PM2.5 (Serious) >=70.
(8) NH3..............................  >=250..................  >=100..................  >=100.
                                                                                         PM2.5 (Serious) >=70.
----------------------------------------------------------------------------------------------------------------
\1\ Thresholds for point source determination shown in tons per year of potential to emit as defined in 40 CFR
  part 70, with the exception of lead. Reported emissions should be in actual tons emitted for the required time
  period.
\2\ Type A sources are a subset of the Type B sources and are the larger emitting sources by pollutant.
\3\ NAA = Nonattainment Area. The point source reporting thresholds vary by attainment status for SO2, VOC, NOX,
  CO, PM10, PM2.5, and NH3.
\4\ OTR = Ozone Transport Region (see 40 CFR 51.1300(t)).

[FR Doc. 2016-27333 Filed 11-16-16; 8:45 am]
 BILLING CODE 6560-50-P