Document ID: EPA-HQ-OAR-2016-0202-0125
Agency: epa
Document Type: Rule
Title: Implementation of the 2015 National Ambient Air Quality Standards for Ozone: Nonattainment Area State Implementation Plan Requirements
Posted Date: 2018-12-06T05:00Z

[Federal Register Volume 83, Number 234 (Thursday, December 6, 2018)]
[Rules and Regulations]
[Pages 62998-63036]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-25424]

[[Page 62997]]

Vol. 83

Thursday,

No. 234

December 6, 2018

Part III

Environmental Protection Agency

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40 CFR Part 51

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

  Federal Register / Vol. 83 , No. 234 / Thursday, December 6, 2018 / 
Rules and Regulations  

[[Page 62998]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 51

[EPA-HQ-OAR-2016-0202; FRL-9986-53-OAR]
RIN 2060-AS82

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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is finalizing 
nonattainment area and ozone transport region (OTR) implementation 
requirements for the 2015 ozone national ambient air quality standards 
(NAAQS) (2015 ozone NAAQS) that were promulgated on October 1, 2015. 
This final rule is largely an update to the implementing regulations 
previously promulgated for the 2008 ozone NAAQS, and we are retaining 
without significant revision the majority of those provisions to 
implement the 2015 ozone NAAQS. This final rule addresses a range of 
nonattainment area and OTR state implementation plan (SIP) requirements 
for the 2015 ozone NAAQS, including 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, emissions inventories, the timing of required SIP 
submissions and compliance with emission control measures in the SIP. 
The EPA is not taking any final action regarding our proposed approach 
for revoking a prior ozone NAAQS and establishing anti-backsliding 
requirements; the agency intends to address any revocation of the 2008 
ozone NAAQS and any potential anti-backsliding requirements in a 
separate future rulemaking.

DATES: This final rule is effective on February 4, 2019.

ADDRESSES: The EPA has established a docket for this action, identified 
by Docket ID No. EPA-HQ-OAR-2016-0202. All documents in the docket are 
listed in the http://www.regulations.gov website. Although listed in 
the index, some information may not be publicly available, e.g., 
Confidential Business Information or other information whose disclosure 
is restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the internet and will be publicly available 
only in hard copy. Publicly available docket materials are available 
electronically in http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: For further general information on 
this final rule, contact Mr. Robert Lingard, Office of Air Quality 
Planning and Standards (OAQPS), U.S. EPA, at (919) 541-5272 or 
[email protected]; or Mr. Butch Stackhouse, OAQPS, U.S. EPA, at 
(919) 541-5208 or [email protected]. For information on the 
Information Collection Request (ICR), contact Mr. Butch Stackhouse, 
OAQPS, U.S. EPA, at (919) 541-5208 or [email protected].

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
CFR Code of Federal Regulations
CO Carbon Monoxide
CTG Control Techniques Guidelines
DOI Department of the Interior
DOT Department of Transportation
EE/RE Energy Efficiency and Renewable Energy
EMFAC EMission FACtors Model
EPA Environmental Protection Agency
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
MOVES Motor Vehicle Emissions Simulator
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
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
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 final 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 final rule as 
regulated sources include owners and operators of sources of emissions 
of volatile organic compounds (VOCs) and nitrogen oxides 
(NOX) that contribute to ground-level ozone formation.

C. 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.

D. How is this notice organized?

    The information presented in this notice is organized as follows:

I. General Information
    A. Preamble Glossary of Terms and Acronyms
    B. Does this action apply to me?
    C. Where can I get a copy of this document and other related 
information?
    D. How is this notice organized?
II. Background and Summary of Final Rule
III. Provisions of the 2008 Ozone NAAQS Implementing Regulations To 
Be Retained Without Significant Revision
    A. Submission Deadlines and Form for Nonattainment Area and OTR 
SIP Elements Due Under CAA Sections 182 and 184
    B. Redesignation to Nonattainment Following Initial Designations
    C. Determining Eligibility for 1-Year Attainment Date Extensions 
for the 2015 Ozone NAAQS Under CAA Section 181(a)(5)
    D. Modeling and Attainment Demonstration Requirements
    E. Requirements for RFP
    F. Requirements for RACT and RACM
    G. CAA Section 182(f) NOX Exemption Provisions
    H. General Nonattainment NSR Requirements
    I. Ambient Monitoring Requirements
    J. Requirements for an OTR
    K. Fee Programs for Severe and Extreme Nonattainment Areas That 
Fail To Attain
    L. Applicability

[[Page 62999]]

    M. International Transport
IV. Provisions of the 2008 Ozone NAAQS Implementing Regulations To 
Be Retained With Specific Revisions
    A. Requirements for RFP: Milestone Compliance Demonstrations
    B. Requirements for RACT: Deadlines for Submittal and 
Implementation of RACT SIP Revisions
    C. Requirements for RACM: Consideration of Sources of Intrastate 
Transport of Pollution
    D. Nonattainment NSR Offset Requirement: Interprecursor Trading 
for Ozone Offsets
    E. 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. Background Ozone
    E. Additional Policies and Programs for Achieving Emissions 
Reductions
    F. Additional Requirements Related to Enforcement and Compliance
    G. Applicability of Final 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. Executive Order 13771: Reducing Regulations and Controlling 
Regulatory Costs
    C. Paperwork Reduction Act (PRA)
    D. Regulatory Flexibility Act (RFA)
    E. Unfunded Mandates Reform Act (UMRA)
    F. Executive Order 13132: Federalism
    G. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    H. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    I. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution or Use
    J. National Technology Transfer and Advancement Act (NTTA)
    K. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
    L. Congressional Review Act (CRA)
    M. Judicial Review
VIII. Statutory Authority

II. Background and Summary of Final Rule

    On October 1, 2015, the EPA promulgated revisions to the primary 
and secondary NAAQS for ozone, setting them at a level of 0.070 parts 
per million (ppm) \1\ (see 80 FR 65292). 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.
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    \1\ 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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    Following revisions to a NAAQS, the EPA and air agencies work 
together to implement the revised NAAQS. To assist air agencies, the 
EPA considers the extent to which existing EPA regulations and guidance 
are sufficient to implement the standard and whether any revisions or 
updates to those regulations and guidance would be helpful or 
appropriate in facilitating the implementation of the revised standard 
by air agencies and regulated entities. The Clean Air Act (CAA or Act) 
does not require that the EPA promulgate new or revised implementing 
regulations or guidance when a NAAQS is revised. However, in certain 
circumstances, the EPA has determined that revisions to implementing 
regulations are necessary to ensure that the CAA's requirements are 
clear for both air agencies and regulated entities. Air agencies are 
required to submit SIPs, as provided in the CAA and in EPA regulations. 
It is important to note that the existing EPA regulations in title 40 
part 51 of the Code of Federal Regulations (CFR) applicable to SIPs 
generally and to particular pollutants (e.g., ozone and its precursors) 
continue to apply even if these regulations are not updated.
    The 1990 CAA Amendments contained ozone NAAQS implementation 
provisions that were specific to the then-current 1-hour ozone NAAQS, 
including regulatory provisions and SIP-related deadlines that do not 
directly apply to the revised 8-hour ozone NAAQS. To fill the resulting 
statutory gaps and provide other needed regulatory guidance, the EPA 
has promulgated several iterations of implementing regulations for the 
8-hour ozone NAAQS that was issued by the EPA in 1997 and revised in 
2008. For purposes of the 2015 ozone NAAQS, the EPA is generally 
applying the overall framework and policy approach of the 
implementation provisions associated with the previous 8-hour NAAQS, 
with the exception of elements addressed in the adverse portions of the 
D.C. Circuit's February 2018 decision in South Coast Air Quality 
Management District v. EPA (discussed later in this preamble), to 
provide for regulatory certainty and consistent implementation across 
time. This overall regulatory framework and policy approach has been 
developed over time with input from numerous stakeholders, including 
the states responsible for fulfilling the CAA's NAAQS implementation 
requirements under the CAA's system of cooperative federalism. The 
framework and policy approach have also been significantly informed by 
numerous court opinions rendered on specific regulatory provisions, 
where the EPA's initial interpretation of the CAA's ozone 
implementation requirements was vacated or otherwise restricted.
    An initial step in implementing a revised NAAQS is the process in 
which states and some tribes 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 our 
proposed and final determinations regarding area designations. Areas 
designated as nonattainment for a revised ozone NAAQS are classified 
(i.e., as Marginal, Moderate, Serious, Severe or Extreme) according to 
the severity of the nonattainment at the time of designation (as 
determined based on the area's ``design value'' (DV)).\2\ The EPA has 
already finalized in a separate action the air quality thresholds 
corresponding with, and attainment dates for, each level of 
nonattainment area classification for the 2015 ozone NAAQS (see 83 FR 
10376; March 9, 2018), which were then applied when the EPA promulgated 
final nonattainment area designations for that standard (see 83 FR 
25766; June 4, 2018 (for most of the U.S.); 83 FR 35136; July 25, 2018 
(for the San Antonio, Texas area)).
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    \2\ 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 
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.
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    On November 17, 2016, the EPA solicited public comment on proposed 
revisions to the ozone NAAQS implementing regulations as they apply to 
the 2015 ozone NAAQS, including the nonattainment area classification 
scheme and SIP requirements, in a notice of proposed rulemaking (NPRM) 
(81 FR 81276). The public comment period for the NPRM ran from November 
17, 2016, to February 13, 2017. The EPA received a total of 79 comment 
submissions on the NPRM. As explained previously, those comments 
relating to the nonattainment area classifications scheme were 
addressed in a separate action in March 2018 finalizing those 
classifications (see generally 83 FR 10376). The preamble to this final 
rule discusses significant comments received on the SIP requirements 
portion of the NPRM and

[[Page 63000]]

how those comments were considered by the EPA in general terms. The 
accompanying Response to Comments document provides more detailed 
responses to the comments received. The public comments received on the 
NPRM and the EPA's Response to Comments document are posted in the 
docket at http://www.regulations.gov (Docket ID No. EPA-HQ-OAR-2016-
0202).
    We are finalizing submittal deadlines and specific CAA requirements 
for the content of nonattainment area and OTR SIPs for the 2015 ozone 
NAAQS in this rule. As a general matter, this final rule follows the 
same basic principles and approach that the EPA applied to interpret 
the CAA's part D ozone nonattainment area requirements in developing 
the implementation rule for the 2008 ozone NAAQS.\3\
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    \3\ See ``Implementation of the 2008 National Ambient Air 
Quality Standards for Ozone: State Implementation Plan 
Requirements'' (80 FR 12264; March 6, 2015), hereafter referred to 
as the 2008 Ozone NAAQS SIP Requirements Rule.
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    In the NPRM, the EPA also proposed and sought comment on two 
alternative approaches for revoking the 2008 ozone NAAQS for all 
purposes and, where applicable, establishing anti-backsliding 
requirements. 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 1 year after the effective date of designation for the 2015 ozone 
NAAQS. Under the second approach, 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; the 2008 ozone NAAQS would in no 
case be revoked 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.
    The EPA's approach to revoking the 1997 ozone NAAQS was challenged 
in South Coast Air Quality Management District v. EPA, 882 F.3d 1138 
(D.C. Cir. 2018) (hereinafter referred to as South Coast II). On 
February 16, 2018, the D.C. Circuit issued a partially adverse decision 
in that case. The EPA is currently assessing the implications of the 
decision on those aspects of the proposal regarding revocation of the 
2008 ozone NAAQS. Thus, the EPA is not acting today on any of the 
proposed revocation options of the 2008 ozone NAAQS or any proposed 
anti-backsliding requirements. The EPA intends to address any 
revocation of the 2008 ozone NAAQS, and any potential anti-backsliding 
requirements in a separate future rulemaking.
    Regarding the format of this preamble, on topics where we made a 
specific proposal, we include detailed information about what we 
proposed, what we are finalizing and our rationale, as well as 
responses to significant comments. As stated previously, we are 
retaining without significant revision the majority of existing 
implementing regulations associated with the 2008 ozone NAAQS for 
purposes of implementing the 2015 ozone NAAQS, as discussed in Section 
III of this preamble. We discuss those aspects of existing implementing 
regulations that we are revising for purposes of implementing the 2015 
ozone NAAQS in Section IV of this preamble. Section V of this preamble 
addresses several topics, relevant to implementing of the 2015 ozone 
NAAQS, on which we solicited public comment in the November 2016 
proposal, but for which we are not promulgating any specific revisions 
to the agency's implementing regulations at this time.

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

    For purposes of implementing the 2015 ozone NAAQS, we are retaining 
without significant revision the majority of regulatory provisions 
previously promulgated for purposes of implementing the 2008 ozone 
NAAQS. The classification and SIP requirement provisions for the 2008 
standards were codified at subpart AA of 40 CFR part 51, and the 
corresponding provisions for the 2015 standards will now be codified in 
subpart CC of part 51.

A. Submission Deadlines and Form for Nonattainment Area and OTR SIP 
Elements Due Under CAA Sections 182 and 184

1. Deadlines for Submitting Nonattainment Area and OTR SIP Elements
    a. Summary of Proposal. The EPA proposed to retain our existing 
approach to establishing deadlines for submitting ozone nonattainment 
area SIP elements. For reference, the final 2008 Ozone NAAQS SIP 
Requirements Rule provides an extensive discussion of the EPA's current 
approach and rationale for SIP element submittal deadlines (80 FR 
12265; March 6, 2015).
    b. Final Rule. The EPA is adopting the proposed approach for 
establishing deadlines for submitting nonattainment area SIP elements 
under CAA section 182 for the 2015 ozone NAAQS, based on the approach 
and rationale articulated in the final 2008 Ozone SIP Requirements 
Rule. Section 182 of the CAA requires states with ozone nonattainment 
areas to submit various SIP elements within specified time periods 
after November 15, 1990 (the date of enactment of the 1990 CAA 
Amendments). For the 2015 ozone NAAQS, the EPA is retaining the 
approach adopted for the 2008 ozone NAAQS: The SIP elements listed will 
generally be due, with the limited exceptions discussed later, 
according to the timeframes provided for those SIP elements in CAA 
section 182, but measured from the effective date of nonattainment 
designation rather than from November 15, 1990.
    Accordingly, states with areas designated nonattainment have: 2 
years from the effective date of a nonattainment designation to submit 
SIP revisions addressing emissions inventories (required by CAA section 
182(a)(1)), RACT (CAA section 182(b)(2)) and emissions statement 
regulations \4\ (CAA section 182(a)(3)(B)); 3 years from the effective 
date of nonattainment designation 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 from the effective date of nonattainment designation to submit 
SIP revisions addressing 3 percent per year \5\ RFP plans (CAA section 
182(c)(2)) and attainment demonstrations for Serious and higher 
classified areas (CAA section 182(c)(2)), 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 for 
the I/M requirements is already codified in 40 CFR 51.372(b)(2) and is 
aligned with the due date for the attainment demonstration SIP for the 
area (i.e., either 3 or 4 years from the effective date of 
nonattainment designation, depending on the area's

[[Page 63001]]

classification: 3 years for Moderate areas, 4 years for Serious and 
higher).
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    \4\ See Section IV.E of this preamble for additional information 
on emissions statements.
    \5\ The 3 percent per year RFP plans are typically submitted in 
3-year increments, i.e., as 9 percent RFP plans that produce average 
reductions of 3 percent of baseline emissions per year.
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    SIP revisions addressing CAA section 185 penalty fee programs in 
areas initially classified Severe or Extreme are due 10 years from the 
effective date of nonattainment designation. The 10-year submittal 
deadline is consistent with section 182(d)(3) of the CAA, which 
provided slightly more than 10 years for submission of the fee program 
SIP revision for areas designated as nonattainment and classified as 
Severe or Extreme by operation of law in 1990 for the 1-hour ozone 
NAAQS.
    SIP submissions addressing nonattainment new source review (NNSR) 
permit program requirements applicable to the 2015 ozone NAAQS are due 
3 years from the effective date of nonattainment designation (see new 
40 CFR 51.1314). This is consistent with the approach articulated in 
the 2008 Ozone NAAQS SIP Requirements Rule. This approach is based on 
the provision in CAA section 172(b) requiring the submission of plans 
or plan revisions ``no later than 3 years from the date of the 
nonattainment designation.''
    We note also that the EPA's past implementing regulations for 
revised ozone NAAQS have required OTR states to submit RACT SIP 
revisions based on the timeframe provided in CAA section 184 as 
measured from the effective date of designations made pursuant to those 
revised NAAQS, rather than from November 15, 1990. 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 nonattainment areas 
for the revised ozone NAAQS. The EPA is adopting these same general 
requirements for the 2015 ozone NAAQS (see Section III.J of this 
preamble).
    c. Comments and Responses. Comment: The only adverse comment the 
EPA received regarding the proposed submittal dates for SIP elements 
for the 2015 ozone NAAQS specifically pertained to the proposed 3-year 
schedule for submitting new or revised SIP elements addressing NNSR 
program requirements. The commenter, objecting to the proposed 3-year 
NNSR SIP due date, claimed that such a timeframe is contrary to CAA 
section 182(a)(2)(C), which, based on the commenter's interpretation, 
affords 2 years for nonattainment areas to submit their NNSR permit 
requirements SIP. The EPA received support for the proposed 3-year NNSR 
SIP revision deadline from two air agency commenters.
    Response: The EPA disagrees with the commenter's argument that a 2-
year maximum deadline for NNSR plans for the 2015 ozone NAAQS is 
required by the CAA. The commenter argues that a 2-year deadline is 
mandated under provisions contained in CAA section 182. As explained in 
the 2008 Ozone NAAQS SIP Requirements Rule (see 80 FR 12267, March 6, 
2015), and the 2015 Ozone NAAQS Implementation Rule Proposal (see 80 FR 
81278, November 17, 2016), the EPA recognized that CAA section 
182(a)(2)(C)(i), under the heading ``Corrections to the State 
implementation plans--Permit programs,'' contains a requirement for 
states to submit SIP revisions to meet the requirements of CAA sections 
172(c)(5) and 173 within 2 years after the date of enactment of the 
1990 CAA Amendments. The EPA continues to support the interpretation of 
the statute that the submission of NNSR SIPs due on November 15, 1992, 
i.e., the date 2 years after enactment of the 1990 CAA Amendments, 
fulfilled this statutory ``corrections'' requirement. The plan 
submittal schedules set forth in the 1990 CAA Amendments at section 
182(a)(2) were applicable to the then existing 1-hour ozone NAAQS, and 
Congress intended them to address SIP-related transition issues unique 
to the transition from provisions ``as in effect immediately before 
November 15, 1990'' to provisions in the newly enacted 1990 CAA 
Amendments.
    The CAA, in the generally applicable subpart 1 provisions of Part D 
of Title I, specifically section 172(b), provides a submittal schedule 
for plan revisions following the EPA's promulgation of ``the 
designation of an area as nonattainment with respect to a national 
ambient air quality standard. . . .'' See 42 U.S.C. 7502(b). At the 
time of the 1990 CAA Amendments, designations for the 1-hour ozone 
NAAQS were already in existence for all areas of the country--including 
nonattainment areas. The 1990 CAA Amendments under Title I Part D 
Subpart 2 added increased programmatic controls and a tiered 
classification structure on top of the existing ozone nonattainment 
designations, imposing still more SIP submission requirements on the 
higher classified areas. Given the existing NNSR programs developed 
under prior statutory authority, it is reasonable to believe that 
Congress thought that the initial NNSR SIP corrections required under 
the newly created section 182(a)(2)(C) could be developed and submitted 
to the EPA quickly. The EPA continues to support the interpretation of 
the statute that the submission of ``corrections to the SIP,'' 
including NNSR SIPs, due on November 15, 1992, fulfilled the statutory 
requirement addressing the SIP revisions associated with the 1-hour 
ozone standard. Hence, the EPA continues to support the interpretation 
that the general NAAQS implementation provisions in CAA subpart 1 at 
section 172(b) govern when the EPA establishes a deadline for the 
submittal of NNSR SIP revisions that are triggered by ozone NAAQS 
revisions occurring after November 15, 1990.
2. Form and Content of Nonattainment and OTR SIP Element Submissions 
Required Under a Revised NAAQS
    a. Summary of Proposal. The EPA proposed to retain our existing CAA 
interpretation that air agencies are required to submit all 
nonattainment SIP elements applicable for an area's classification 
following revision of the NAAQS. The EPA also took comment on an option 
for air agencies to submit a certification statement for previously 
approved SIP elements. When submitting SIP elements, air agencies may 
certify that an existing regulation is adequate to meet certain 
nonattainment area planning requirements for a revised ozone NAAQS, in 
lieu of submitting a new revised regulation.
    b. Final Rule. The EPA is finalizing the proposed requirements. We 
continue to interpret the general SIP requirements of subpart 1 of part 
D of Title I and the specific nonattainment area planning requirements 
of CAA section 182 to require air agencies to submit a SIP element to 
meet each nonattainment area planning requirement for the 2015 ozone 
NAAQS. Many air agencies already have regulations in place to address 
certain nonattainment area planning requirements 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 
the revised ozone NAAQS.\6\ 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 
the state's nonattainment areas and relevant classes and categories of 
sources for the 2015 ozone NAAQS, and that is likely to be sufficient 
for purposes of meeting

[[Page 63002]]

the emissions statement requirement for the 2015 ozone NAAQS. Where an 
air agency determines that an existing regulation is adequate to meet 
applicable nonattainment area planning requirements of CAA section 182 
(or OTR RACT requirements of CAA section 184) for a revised ozone 
NAAQS, that air agency's SIP revision may provide a written statement 
certifying that determination in lieu of submitting new revised 
regulations. The EPA has acted on similar certifications in the past. 
See e.g., 83 FR 26221 (June 6, 2018) (explaining that the EPA is 
approving Pennsylvania's certification that the state's previously 
approved emissions statement 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 ozone 
NAAQS might include (but are not necessarily limited to): NNSR, vehicle 
I/M programs and clean fuels requirement for boilers.
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    \6\ This review should include determining whether the 
nonattainment area boundary for the current ozone NAAQS is 
consistent with the boundary for the previous standards.
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    An air agency choosing to provide a written certification in lieu 
of submitting a new or revised regulation must provide the 
certification to the EPA qualifying as a SIP revision in accordance 
with CAA section 110 and 40 CFR 51.102, 103 and part 51 Appendix V. An 
air agency should identify the related applicable requirements and 
explain 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 area 
planning requirements for the new NAAQS. These written statements must 
be treated in the same manner as any other SIP submission and must be 
provided to the EPA in accordance with applicable SIP submission 
requirements and deadlines.
    In cases where a previously approved regulation is modified for any 
reason, or where no regulation exists, air agencies must provide the 
new or modified regulation as a SIP submission. This would include new 
or modified RACT provisions for states with nonattainment areas and 
states in an OTR resulting from a new review of major source emission 
controls.
    c. Comments and Responses. Comment: Several commenters objected to 
the EPA's expectation that states certify the adequacy of previously 
approved SIP elements for a revised NAAQS with written statements, 
through the same process as other SIP revisions. They argue the 
certification process is redundant and therefore a waste of resources 
because the EPA already has several processes to ensure that states 
meet CAA section 110 planning obligations including infrastructure 
SIPs. Two commenters supported the EPA's option for SIP certification 
statements, citing its benefits in streamlining the SIP development 
process.
    Response: The EPA disagrees with commenters that SIP certification 
statements triggered by a NAAQS revision are redundant and already 
accomplished through other SIP processes, including infrastructure 
SIPs. As noted previously, we continue to interpret the general SIP 
requirements of CAA section 110 and specific nonattainment planning 
requirements of CAA section 182 to require an air agency to provide a 
SIP submission to meet each nonattainment area planning requirement for 
a revised ozone NAAQS. To the extent that commenters suggest the EPA 
should adopt a general presumption of adequacy for previously approved 
SIP elements, we disagree. We note in particular that the 
infrastructure SIP submission triggered by a NAAQS revision provides 
the public and the EPA an opportunity to review the basic structure of 
a state's air quality management program and is not intended--nor can 
it be presumed--to address the adequacy of individual nonattainment SIP 
elements for purposes of the revised NAAQS.
    The submission of individual nonattainment SIP elements for 
purposes of the revised NAAQS provides the public and the EPA an 
opportunity to review and comment upon each element of a nonattainment 
SIP. If the air agency reviews an existing SIP element and concludes it 
does not need to be revised in light of the new NAAQS, submission of a 
certification SIP allows the public to review the air agency's 
assessment and provide comment on any changes they may think necessary. 
The EPA then also has an opportunity to review the air agency's 
assessment and ensure that it is consistent with CAA requirements in 
relation to the revised 2015 ozone NAAQS.
    As noted by other commenters, the certification statement option is 
intended to streamline the SIP submission process, providing air 
agencies with the flexibility to address multiple SIP elements in a 
single certification statement, and combine the SIP certification 
action with other actions subject to public notice and comment. The EPA 
does not believe that developing and submitting certification SIP 
elements will be a significant and unnecessary drain on state 
resources.

B. Redesignation to Nonattainment Following Initial Designations

1. Summary of Proposal
    The EPA proposed to retain our existing requirements concerning 
SIP-related deadlines for areas initially designated attainment for a 
current ozone NAAQS and subsequently redesignated to nonattainment for 
the same standards. These requirements are codified for the 2008 ozone 
NAAQS at 40 CFR 51.1106.
2. Final Rule
    The EPA is finalizing the proposed requirements. The newly adopted 
provisions, codified at 40 CFR 51.1306, generally allow an extension of 
any absolute, fixed date applicable to 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 the redesignation, unless otherwise provided in the 
implementation provisions for the 2015 ozone NAAQS.\7\ The maximum 
attainment date for a redesignated area would be based on the area's 
classification.
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    \7\ For example, the adopted RACT provisions at 40 CFR 
51.1312(a)(3)(ii) for reclassified nonattainment areas (which would 
include areas redesignated to nonattainment) require that RACT SIP 
revisions be implemented as expeditiously as practicable, but no 
later than the start of the attainment year ozone season 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 (see Section IV.B of this preamble).
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3. Comments and Responses
    The EPA received no adverse comments on the proposed requirements.

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

1. Summary of Proposal
    The EPA proposed to retain our existing approach for eligibility 
criteria for 1-year attainment date extensions under CAA section 
181(a)(5). These criteria are codified for the 1997 ozone NAAQS in 40 
CFR 51.907 and for the 2008 ozone NAAQS in 40 CFR 51.1107, and we 
proposed to retain the same approach for purposes of the 2015 ozone 
NAAQS.
2. Final Rule
    The EPA is finalizing the proposed approach. Under the newly 
adopted provisions, codified at 40 CFR 51.1307, an area that fails to 
attain a specific ozone NAAQS by its attainment date

[[Page 63003]]

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).
    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 our state counterparts, and 
the EPA has long interpreted the provision to be satisfied by such 
statements.\8\ 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 the 
state is complying with its applicable federally approved SIP.
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    \8\ See ``Procedures for Processing Bump Ups and Extension 
Requests for Marginal Ozone Nonattainment Areas,'' Memorandum from 
D. Kent Berry, Acting Director, Air Quality Management Division, 
U.S. EPA, February 3, 1994.
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3. Comments and Responses
    Comment: The EPA received general support for retaining the current 
1-year attainment date extension approach. One commenter requested that 
either the EPA codify clear and specific instructions on the criteria 
that must be met, beyond the monitoring requirements in proposed 
section 51.1307, or that the EPA update guidance for ozone to 
correspond with the carbon monoxide (CO) attainment date extension 
guidance \9\ since the EPA ties consideration of an attainment date 
extension for CO to a state's ``substantial'' efforts to reduce 
emissions.
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    \9\ The CO guidance referenced is contained in the Sally Shaver 
memo, ``Criteria for Granting Attainment Date Extensions, Making 
Attainment Determinations, and Determinations of Failure to Attain 
the NAAQS for Moderate CO Nonattainment Areas'' (10/23/95), 
available at: https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/19951023_shaver_attainment_extension_co_naa.pdf.
---------------------------------------------------------------------------

    Response: We disagree with the commenter that the EPA should codify 
instructions or develop separate guidance for granting attainment date 
extensions under an ozone NAAQS. CAA section 181(a)(5)(A) requires a 
state to have complied with all applicable SIP requirements and 
commitments to qualify for an attainment date extension. As discussed 
previously, the EPA has long interpreted CAA section 181(a)(5)(A) as 
permitting the agency to rely upon the certified statements of our 
state counterparts that a state has complied with all applicable ozone 
SIP requirements and commitments to qualify for an attainment date 
extension. In practice, we have found this approach for ozone NAAQS 
implementation to be reasonable and sufficient, and do not intend to 
develop separate 1-year attainment deadline extension guidance for the 
ozone NAAQS at this time.

D. Modeling and Attainment Demonstration Requirements

1. Summary of Proposal
    The EPA proposed to retain our 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 for 
the 2015 ozone NAAQS. 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 ``Modeling Guidance for 
Demonstrating Attainment of Air Quality Goals for Ozone, 
PM2.5, and Regional Haze'' (November 2018).\10\
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    \10\ Modeling guidance, tools and supporting documents for SIP 
attainment demonstration are available at: http://www3.epa.gov/scram001/guidance_sip.htm.
---------------------------------------------------------------------------

2. Final Rule
    The EPA is finalizing modeling requirements as outlined in the 
proposal, and adopted at 40 CFR 51.1308. The EPA continues to believe 
the modeling requirements established in the final 2008 Ozone NAAQS SIP 
Requirements Rule are reasonable, primarily because photochemical 
modeling is generally available and reasonable to employ. However, this 
requirement also explicitly allows for another analytical method, 
determined by the Administrator to be at least as effective as 
photochemical modeling, to be substituted for or used to supplement a 
photochemical modeling-based assessment of an emissions control 
strategy. Any alternative analysis should be based on technically 
credible methods that allows for the timely submittal of the attainment 
demonstration. States should review the EPA modeling guidance \11\ and 
consult their appropriate EPA Regional office before proceeding with 
alternative analyses. Under CAA section 182(a), states are not required 
to submit an attainment demonstration SIP for Marginal areas. The EPA 
offers assistance to states as they consider the most appropriate 
course of action for Marginal areas that may be at risk of failing to 
meet the NAAQS within the applicable 3-year timeframe. If necessary, 
states can choose to adopt additional controls for such areas or they 
can request a voluntary reclassification to a higher classification 
category. The EPA believes that voluntary reclassification for areas 
that are not likely to attain by their attainment date may facilitate 
quicker attainment, including through the development of the attainment 
plans required of Moderate and higher classified areas.
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    \11\ The modeling guidance can be found in the EPA's ``Guidance 
on the Use of Models and Other Analyses for Demonstrating Attainment 
of Air Quality Goals for Ozone, PM2.5, and Regional 
Haze,'' available at: https://www3.epa.gov/scram001/guidance/guide/final-03-pm-rh-guidance.pdf.
---------------------------------------------------------------------------

3. Comments and Responses
    Comment: One commenter stated that the EPA should finalize our 2014 
draft modeling guidance. Another commenter stated that the use of 
photochemical grid modeling (or equivalent) for attainment 
demonstrations should be left to a state's discretion.
    Response: The EPA acknowledges the need to update modeling guidance 
and has recently released an updated (November 2018) version, as 
described previously.

[[Page 63004]]

    In regard to the use of photochemical grid modeling, the EPA is 
retaining the same modeling and attainment demonstration requirements 
as established in the final 2008 Ozone NAAQS SIP Requirements Rule. CAA 
section 182(c)(2)(A) contains specific requirements for states to use 
photochemical modeling or another analytical method determined to be at 
least as effective in their SIPs for Serious and higher classified 
nonattainment areas. Since photochemical modeling is the most 
scientifically rigorous technique to determine NOX and/or 
VOC emissions reductions needed to show attainment of the NAAQS and is 
readily available, we are requiring photochemical modeling (or another 
analytical method determined to be at least as effective) for all 
attainment demonstrations (including Moderate areas). We continue to 
believe that photochemical modeling is the most technically credible 
method of estimating future year ozone concentrations based on 
projected VOC and NOX precursor emissions.

E. Requirements for RFP

1. Summary of Proposal
    The EPA proposed in general to retain our existing approach for RFP 
requirements and to add new regulatory provisions codifying statutory 
requirements for RFP milestone compliance demonstrations (MCDs) (see 
Section IV.A of this preamble). The EPA also sought comment on 
requiring states to use the year of an area's designation as 
nonattainment as the baseline year for the emissions inventory for the 
RFP requirement.
    The existing RFP requirements for the 2008 ozone NAAQS are codified 
in 40 CFR 51.1110 and are organized by the following major subjects: 
Submission deadline for SIP revisions; RFP requirements for affected 
areas; \12\ creditability of emission control measures; creditability 
of out-of-area emissions reductions; calculation of non-creditable 
emissions reductions; and baseline emissions 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).
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    \12\ 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 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.
---------------------------------------------------------------------------

    In general terms, ozone nonattainment areas must achieve RFP toward 
attainment of the ozone NAAQS, as established in the RFP provisions of 
subparts 1 and 2 of part D of the CAA. Section 172(c)(2) of subpart 1 
requires that nonattainment SIPs must provide for RFP, defined in CAA 
section 171(1) as ``such annual incremental reductions in emissions'' 
as required by CAA part D or as required by the Administrator for 
ensuring attainment of the NAAQS. Subpart 2 establishes specific 
percent reduction targets for ozone nonattainment areas. For Moderate 
and higher classified areas, CAA section 182(b)(1) requires a 15 
percent reduction in VOC emissions from the baseline anthropogenic 
emissions within 6 years after November 15, 1990 (this RFP requirement 
is also referred to as ROP). The 15 percent ROP requirement must be met 
by the end of the 6-year period regardless of when the nonattainment 
area attains the NAAQS. For an area that already has an approved SIP 
providing for the 15 percent ROP requirement for VOC under either the 
1-hour ozone NAAQS or a prior 8-hour ozone NAAQS, the EPA proposed that 
the area would not need to meet that requirement again. Instead, such 
areas would be treated like areas covered under CAA section 172(c)(2) 
if they are classified as Moderate for the 2015 ozone NAAQS. The EPA 
proposed to retain our existing interpretation of CAA section 172(c)(2) 
to require such areas to obtain 15 percent reductions in ozone 
precursor emissions over the first 6 years after the baseline year. For 
areas classified Serious and higher, the EPA proposed to retain our 
existing interpretation of CAA section 182(c)(2)(B) to require such 
areas to obtain 18 percent ozone precursor emission reductions in that 
6-year period.\13\ For areas classified Serious and higher, CAA section 
182(c)(2)(B) requires an additional 3 percent per year reduction from 
baseline VOC emissions, averaged over consecutive 3-year periods, 
beginning 6 years after November 15, 1990, and applying each year until 
the attainment date. CAA section 182(c)(2)(B) also allows 
NOX reductions to be substituted for VOC reductions under 
certain conditions to meet the 3 percent per year RFP requirement.
---------------------------------------------------------------------------

    \13\ Similar interpretations were made for the 1997 ozone NAAQS 
in the Phase 2 Ozone Implementation Rule (70 FR 71615, November 29, 
2005), which were upheld in NRDC v. EPA, 571 F.3d 1245 (D.C. Cir. 
2009), and for the 2008 ozone NAAQS in the 2008 Ozone NAAQS SIP 
Requirements Rule (80 FR 12271, March 6, 2015), which were upheld in 
South Coast II, 882 F.3d 1138 (D.C. Cir. 2018).
---------------------------------------------------------------------------

    The EPA proposed that the default baseline year for RFP would be 
the calendar year for the most recently available triennial emissions 
inventory at the time ROP/RFP plans are developed (e.g., 2017 for 
initial designations effective in 2018). We further proposed that 
states may use an alternative year (i.e., a year other than 2017) 
between the year of the revised NAAQS issuance (2015) and the year in 
which nonattainment designation is effective. Consistent with our 
approach for the 2008 ozone NAAQS, we proposed that all states 
associated with a multi-state nonattainment area must consult and agree 
on a single RFP baseline year for the area. The EPA also invited 
comment on an alternative approach of requiring that states use the 
year of the effective date of an area's designation as the baseline 
year for the emissions inventory for the RFP requirements.
2. Final Rule
    The EPA is finalizing most aspects of our proposals for 
implementing the CAA's RFP provisions for purposes of the 2015 ozone 
NAAQS, as adopted at 40 CFR 51.1310. In general, the EPA is following 
essentially the same interpretation of CAA subpart 2 requirements for 
RFP as was applied to areas for the 2008 and 1997 8-hour ozone 
standards, with exceptions noted in this section. Areas classified 
Moderate for the 2015 ozone NAAQS that had SIPs previously approved to 
meet the ROP requirements for the 1-hour, 1997 8-hour or 2008 8-hour 
ozone NAAQS would be treated like areas covered under CAA section 
172(c)(2), and would need to meet the 3 percent per year RFP 
requirements under CAA section 182(c)(2)(B) if they are classified 
Serious or higher for the 2015 standards. For the purposes of the 2015 
ozone NAAQS, the EPA continues to interpret CAA section 172(c)(2) as 
requiring Moderate areas with an approved SIP under the 1-hour ozone 
NAAQS or prior 8-hour ozone NAAQS to achieve 15 percent ozone precursor 
(NOX and/or VOC) emission reductions over the first 6 years 
after the RFP baseline year for the 2015 ozone NAAQS. For areas 
classified Serious and higher, the EPA continues to interpret CAA 
section 182(c)(2)(B) to require such areas to obtain 18 percent ozone 
precursor emission reductions in that 6-year period. This 
interpretation was recently upheld in a challenge to the 2008 Ozone 
NAAQS SIP Requirements Rule in South Coast II, 882 F.3d at 1153. The 
EPA also continues to interpret CAA

[[Page 63005]]

section 182(c)(2)(B) for the 2015 ozone NAAQS as requiring an 
additional 3 percent per year reduction from baseline emissions, 
averaged over consecutive 3-year periods, beginning 6 years after the 
RFP baseline year, and applying each year until the attainment date.
    For the RFP baseline year for the 2015 ozone NAAQS, we are 
specifying that the baseline year shall be the calendar year for the 
most recently available triennial emissions inventory preceding the 
year of the area's effective date of designation as a nonattainment 
area. This approach was recently upheld by the D.C. Circuit in South 
Coast II. Alternatively, states may choose to use the year that 
corresponds with the year of the effective date of an area's 
nonattainment designation for the RFP baseline year.
    For purposes of the 2008 ozone NAAQS, the EPA selected 2011 as a 
baseline year because it is tied to the 3-year statutory cycle for 
emissions inventories, and preceded the year in which nonattainment 
area designations for the 2008 ozone NAAQS were effective (i.e., 2012). 
The D.C. Circuit in South Coast II upheld this approach as reasonable, 
because the chosen baseline year was tied to the triennial emissions 
inventory states must prepare. South Coast II, 882 F.3d at 1152. 
Further, we note that the EPA has historically interpreted RFP 
``baseline emissions'' (CAA section 182(b)(1)(B)) as corresponding with 
the initial emissions inventory in CAA section 182(a) (see, e.g., 80 FR 
12290; March 6, 2015).\14\ For an ozone NAAQS revision occurring after 
the CAA was amended in 1990, we interpret the periodic triennial 
inventory required by CAA section 182(a)(3) as effectively supplanting 
the initial emissions inventory required by CAA section 182(a)(1), 
because the revised periodic inventory must meet the same requirements 
as the initial emissions inventory. We therefore believe it is a 
reasonable interpretation of the CAA that RFP baseline year emissions 
may correspond with the calendar year and contents of the triennial 
inventory required by CAA section 182(a)(3). We are finalizing our 
approach that states shall use an RFP baseline year for the 2015 ozone 
NAAQS that corresponds with the calendar year for the most recent 
triennial emissions inventory preceding the year of the area's 
effective date of nonattainment designation. For example, states with 
areas designated nonattainment in 2018 would use 2017 as the RFP 
baseline year, which would be the year of the most recent triennial 
emissions inventory.
---------------------------------------------------------------------------

    \14\ CAA section 182(b)(1)(B) defines ``baseline emissions'' as 
the total amount of actual VOC or NOX emissions from 
anthropogenic sources in the area during calendar year 1990, which 
we have interpreted as corresponding with the emissions inventory 
for the area as of November 15, 1990; the development of an 
emissions inventory with that reference date was required under CAA 
section 182(a)(1).
---------------------------------------------------------------------------

    For purposes of the 2015 ozone NAAQS, states may also use an 
alternative RFP baseline year that corresponds with the year of the 
effective date of an area's designation. This adopted approach for the 
2015 ozone NAAQS revises the approach provided in the 2008 Ozone NAAQS 
SIP Requirements Rule, which allowed the state to select an alternative 
RFP baseline year between the year of the revised NAAQS issuance (i.e., 
2008) and the year in which nonattainment designations were effective 
(i.e., 2012), so long as the state could explain why the alternative 
year was appropriate. The EPA's creation of the state-selected 
alternative RFP baseline year option for the 2008 Ozone NAAQS SIP 
Requirements Rule was rejected by the court in South Coast II, because 
the court found that the EPA failed to provide a statutory 
justification for why alternative baselines were appropriate. South 
Coast II, 882 F.3d at 1153. As noted previously, the EPA sought comment 
on an alternative approach that would have required states to use the 
year of the effective date of an area's designation (designation year) 
as the baseline year for the RFP emissions inventory instead of the 
triennial emissions inventory year.
    As explained earlier, for purposes of the 2015 ozone NAAQS, we are 
specifying that the baseline year shall be the calendar year for the 
most recently available triennial emissions inventory preceding the 
year of the area's effective date of designation as a nonattainment 
area, but also allowing an alternative approach that provides states 
the option to use an area's designation year as the baseline year for 
RFP. This alternative option is grounded in our interpretation of the 
RFP requirement in CAA section 182(b)(1)(B), which defines ``baseline 
emissions'' in terms of total VOC and NOX emissions in the 
area ``during the calendar year 1990.'' There is clear ambiguity in the 
statutory language at issue, since we do not believe Congress intended 
1990 to be the baseline year for RFP requirements for all future ozone 
NAAQS. Therefore, the EPA must develop a reasonable interpretation of 
the baseline year provisions at issue. Note that section 93.119(e)(4) 
of the EPA's transportation conformity rule requires that for any NAAQS 
promulgated after 1997 the baseline year is the ``most recent year for 
which the EPA's Air Emissions Reporting Requirements (AERR) (40 CFR 
part 51, subpart A) requires submission of on-road mobile source 
emissions inventories as of the effective date of designations.'' For 
nonattainment areas for the 2015 ozone NAAQS, 2017 is the baseline year 
for transportation conformity purposes.
    The calendar year 1990 is tied to the November 15, 1990, date of 
passage of the 1990 CAA Amendments, which ``is the date on which 
Congress specified that the initial designations/classifications . . . 
under the 1990 amendments would take effect.'' NRDC v. EPA, 777 F.3d 
456 (D.C. Cir. 2014) (citing 42 U.S.C. 7407(d)(1)(C), 7511(a)(1)). 
Thus, for the 1-hour standard, the RFP baseline year was ``calendar 
year 1990,'' which was both the year of the initial emissions inventory 
required by CAA section 182(a)(1) and the year of designations. 
However, for future promulgations and revisions of NAAQS, the year of 
designations and the year of the most recent triennial emissions 
inventory may not coincide--and for the 2015 ozone NAAQS, they do not. 
Where they do not coincide, no single year can be selected that 
presents both the attributes that 1990 did in the context of the 
Amendments and the subsequent implementation process. Accordingly, we 
believe that in the context of implementing a NAAQS for which these 2 
years do not coincide, the textual reference in the RFP requirement's 
``baseline emissions'' provision reference to the ``calendar year 
1990'' (CAA section 182(a)(1)) can be reasonably read to refer to that 
year either as an area's year of initial designation or as the year of 
the relevant emissions inventory. We therefore believe it is a 
reasonable interpretation of the statute that states should be able to 
use an area's designation year for the 2015 ozone NAAQS as the RFP 
baseline year, as an alternative to the calendar year for the most 
recent triennial emissions inventory. All states associated with a 
multi-state nonattainment area must consult and agree on using the 
alternative baseline year.
3. Comments and Responses
    Comment: The EPA received broad support for our proposal to retain 
the existing flexible approach to establishing an RFP baseline year. 
Commenters noted that an RFP baseline year fixed to an area's 
designation may not synchronize with the most recently available 
triennial emissions inventory at the time ROP/RFP plans are

[[Page 63006]]

developed, may not be representative of ozone-producing conditions for 
the area, and/or would not account for early actions to reduce ozone 
precursor emissions. A fixed RFP baseline year could necessitate 
preparing separate emissions inventories, e.g., for attainment 
demonstration modeling and RFP, at additional time and cost for air 
agencies with limited resources.
    Response: As discussed previously, the EPA's creation of the state-
selected alternative RFP baseline year option for the 2008 Ozone NAAQS 
SIP Requirements Rule was rejected by the court in South Coast II, 
because the court found that the EPA failed to provide a statutory 
justification for why alternative baselines were appropriate. We agree 
with the commenter that under certain circumstances a single fixed RFP 
baseline year could increase resource burden for air agencies. Thus, we 
are adopting an approach for the 2015 ozone NAAQS that syncs the RFP 
baseline with triennial emissions inventory reporting years, but 
permits states to alternatively choose the year of designation.
    Comment: One commenter argued that the EPA's existing RFP baseline 
year approach is illegal because the Act plainly specifies the RFP 
baseline year in CAA section 182(b)(1)(B) (i.e., calendar year 1990), 
and that RFP requirements would therefore be triggered--and the RFP 
baseline year would be set--by the date an area is designated for the 
revised NAAQS. The commenter claimed that where Congress wanted to 
authorize variation in implementing the ozone NAAQS, it did so 
expressly (e.g., allowing the Administrator to adjust SIP deadlines for 
reclassified areas under CAA section 182(i)).
    Response: As discussed previously, the court in South Coast II 
upheld the EPA's selection of 2011, i.e., the most recent year from the 
3-year statutory cycle for emissions inventories, as the default RFP 
baseline year for the 2008 ozone NAAQS as reasonable. We are adopting 
this same approach for the 2015 ozone NAAQS, while also allowing states 
to choose an alternative RFP baseline year corresponding with an area's 
designation year. For the reasons cited previously, we believe both 
options are reasonable interpretations of the CAA's RFP provisions in 
adapting those provisions to revised ozone NAAQS.
    Comment: A commenter objected to the EPA's proposed interpretation 
of CAA section 182(b)(1) that would consider areas with an approved 15 
percent ROP plan under a prior ozone NAAQS to have satisfied the 15 
percent ROP requirement for the 2015 ozone NAAQS. The EPA applied this 
interpretation previously for purposes of the 1997 and 2008 8-hour 
ozone standards. The commenter claimed that the proposed 15 percent ROP 
requirement illegally allows ``paper-only'' reductions to substitute 
for the actual emission reductions intended by Congress and articulated 
in the general rule for creditability of ROP reductions in CAA section 
182(b)(1)(C) (i.e., the required reductions are creditable ``to the 
extent they have actually occurred'').
    Another commenter objected to the 15 percent ROP requirement in 
general, describing it as outdated, not necessitated under the current 
ozone standards, and increasingly difficult to achieve given the 
decreases in ozone precursor emissions that have occurred since the CAA 
was amended in 1990. If the EPA continues to implement the 15 percent 
ROP requirement, the commenter argues that required emission reductions 
should be measured against the 1990 baseline in all cases, and that 
states should have discretion to apply NOX or VOC reductions 
toward the initial 15 percent (VOC) ROP increment.
    Response: The EPA disagrees that a state must demonstrate that an 
area actually achieved the 15 percent ROP within 6 years of the 
baseline year for a prior NAAQS. Consistent with the decision in NRDC 
v. EPA, 571 F.3d 1235 (D.C. Cir. 2009), we continue to maintain that if 
a state has already met the requirement to submit for approval and to 
implement a nonattainment area ROP/RFP emissions reduction plan to meet 
the requirements of CAA section 182(b)(1)(A) for either the 1-hour 
standard or a prior 8-hour standard, the state will not have to meet it 
again for the 2015 ozone NAAQS. As noted previously, the court in South 
Coast II affirmed this approach for purposes of the 2008 Ozone NAAQS 
SIP Requirements Rule.
    We also disagree with the comment that the 15 percent ROP is not 
necessary under current ozone standards and that, if required by the 
EPA, it should be measured against the 1990 baseline in all cases. The 
RFP regulation must comply with the CAA, and section 182(b)(1) of the 
CAA explicitly requires that ozone nonattainment areas classified as 
Moderate or higher submit an ROP plan to achieve a 15 percent reduction 
in VOC baseline emissions over a 6-year period following the baseline 
year. We continue to believe it is reasonable to interpret that 
baseline year as the one associated with the revised ozone NAAQS and 
not the year 1990 associated with the then-current 1-hour NAAQS. A 1990 
baseline year for areas designated in 2018 would be impractical and an 
absurd result, especially for areas that were not nonattainment for the 
ozone NAAQS in 1990 and thus never subject to a past requirement to 
develop and use a 1990 nonattainment area emissions inventory for 
purposes of RFP. Assessing 15 percent ROP only during the period 1990-
1996 would be meaningless for a nonattainment area that must in 2018 
begin achieving emissions reductions to meet an ozone NAAQS with an 
attainment date in a year after 2018.
    Comment: A number of commenters disagreed with the EPA's proposed 
requirement that creditable emission reductions for 15 percent ROP and 
3 percent RFP must be obtained from sources within the nonattainment 
area. Several of the commenters referenced our proposed requirement 
regarding control measures for out-of-area sources in a state's 
jurisdiction (see Section IV.C of this preamble), and questioned 
whether it was reasonable that the EPA could require out-of-area 
emission reductions for attainment purposes, while not crediting those 
reductions toward RFP.
    Response: The EPA disagrees with the commenters. The proposed 
requirement that emission reductions must be obtained from within the 
nonattainment area to be creditable for ROP and RFP is the same as that 
adopted in the 2008 Ozone NAAQS SIP Requirements Rule, which was 
challenged and upheld in South Coast II. The court in South Coast II 
declared that the related statutory text is unambiguous, noting that 
RFP is measured from ``baseline emissions,'' which is defined in the 
CAA as ``the total amount of actual VOC or NOX emissions 
from all anthropogenic sources in the area during the'' baseline 
year.\15\ The court noted the singular term ``the area'' appears in a 
CAA section titled ``Moderate Areas,'' and not a greater area (CAA 
section 182(b); see also CAA section 182(c)). The court concluded, in 
considering the grammar and context of the CAA's RFP provisions, that 
``in the area'' unambiguously refers to baseline emissions within the 
nonattainment area. South Coast II, 882 F.3d at 1146-47. Accordingly, 
the EPA concludes, as we did in the 2008 Ozone NAAQS SIP Requirements 
Rule, that we have no legal basis for allowing RFP credits for 
reductions outside the nonattainment area.
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    \15\ See CAA sections 182(b)(1)(A), (b)(1)(B), (c)(2)(B), (d) 
and (e).

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[[Page 63007]]

F. Requirements for RACT and RACM

1. RACT
    a. Summary of Proposal. The EPA proposed to retain our existing 
general RACT requirements, which are codified for the 2008 ozone NAAQS 
at 40 CFR 51.1112, and to add new deadline requirements for certain 
RACT SIP submissions (see Section IV.B of this preamble). 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 RACT in their nonattainment SIPs (80 FR 12278; 
March 6, 2015).
    b. Final Rule. The EPA is retaining our existing general RACT 
requirements for purposes of the 2015 ozone NAAQS. These requirements, 
which are being codified at 40 CFR 51.1312(a) and (b), address the 
content and timing of RACT SIP submittals and implementation, as well 
as major source criteria for RACT applicability.\16\ Underlying these 
general RACT requirements are well-established EPA policies and 
guidance, including existing control techniques guidelines (CTGs) and 
alternative control techniques (ACTs).\17\ Consistent with the EPA's 
prior guidance (80 FR 12279; March 6, 2015), when determining what is 
RACT for a particular source or source category, air agencies should 
also consider all other relevant information (including recent 
technical information and information received during the state's 
public comment period) that is available at the time they develop their 
RACT SIPs. The EPA's adopted RACT approach includes our longstanding 
policy with respect to ``area wide average emission rates.'' This 
policy recognizes that states may demonstrate as part of their 
NOX RACT SIP submission that the weighted average 
NOX emission rate of all sources in the nonattainment area 
subject to RACT meets NOX RACT requirements; states are not 
required to demonstrate RACT-level controls on a source-by-source 
basis. This approach for demonstrating RACT through area-wide average 
emissions rates was recently upheld in South Coast II, 882 F.3d at 
1154. The EPA is also finalizing new submittal and implementation 
deadlines for certain RACT SIP revisions, as discussed in Section IV.B 
of this preamble.
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    \16\ The EPA has defined RACT as the most stringent 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. See related 
discussion in ``Guidance for Determining Acceptability of SIP 
Regulations in Non-Attainment Areas,'' Memorandum from Roger 
Strelow, Assistant Administrator for Air and Waste Management, to 
Regional Administrators (December 9, 1976) (Strelow Memorandum) and 
the proposed General Preamble Supplement in 44 FR 53762 (September 
17, 1979). Availability and feasibility may differ across sources in 
the same category. See ``Criteria for Determining RACT in Region 
IV,'' Memorandum from John Calcagni, Chief, Economic Analysis 
Branch, to G.T. Helms, Jr., Chief, Control Programs Operations 
Branch (June 19, 1985).
    \17\ The EPA's CTGs and ACTs are available at: https://www.epa.gov/ozone-pollution/control-techniques-guidelines-and-alternative-control-techniques-documents-reducing.
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    c. Comments and Responses. Comment: Two commenters stated that the 
EPA should extend the submittal deadline for RACT SIPs from 24 months 
to 36 months following the effective date of a nonattainment area's 
designation.
    Response: The EPA has considered the comments regarding an extended 
submittal deadline for RACT SIP revisions, but, given the uncertainty 
regarding the statutory basis for providing such flexibility, does not 
interpret CAA section 182(b)(2) to allow extending the deadline for 
RACT SIP submissions triggered by initial nonattainment area 
designations. We are instead adopting an interpretation consistent with 
the requirement in the 2008 Ozone NAAQS SIP Requirements Rule that RACT 
SIP submissions triggered by initial nonattainment area designations 
must be submitted based on the timeframe provided in CAA section 
182(b)(2), i.e., no later than 24 months after the effective date of 
nonattainment designation for a specific ozone NAAQS. As discussed in 
Section IV.B of this preamble, the EPA is adopting an alternative 
approach for RACT SIP revisions triggered by nonattainment area 
reclassifications or the issuance of a new CTG.
    Comment: Several commenters objected to the EPA proposing to retain 
our ``area wide average emission rates'' approach for RACT. They 
contend that the emissions averaging policy violates the clear terms of 
the CAA, which they argue requires each individual source to meet the 
NOX RACT requirement. One commenter provided a legal 
analysis of statutory language and legislative history as confirming 
the source-specific basis of RACT requirements. The same commenter also 
pointed to the EPA's previous RACT guidance \18\ and the NOX 
RACT exemption provisions of CAA section 182(f)(1) and (2) as further 
evidence of RACT's source-specific basis.
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    \18\ See Strelow Memorandum.
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    Response: The EPA disagrees with the commenters. As mentioned 
previously, the D.C. Circuit recently upheld the RACT emissions 
averaging policy with respect to the 2008 ozone NAAQS, and we are 
retaining it for purposes of the 2015 ozone NAAQS. The court held that 
``the plain language [of the CAA]--in the context of the 
interrelationship between [42 U.S.C. sections] 7511a(b)(2) and 
7502(c)(1)--does not mandate RACT for each individual source.'' South 
Coast II, 882 F.3d at 1154. In addition to holding that the CAA does 
not require the approach advanced by the commenters, the court further 
held that the EPA's area-wide emissions averaging approach for the 2008 
ozone NAAQS, which is adopted again here for the 2015 ozone standards, 
is reasonable. Id. (``The EPA's interpretation reasonably allows 
nonattainment areas to meet RACT-level emissions requirements through 
averaging within a nonattainment area.'').
2. RACM
    a. Summary of Proposal. The EPA proposed to retain our existing 
RACM requirements, which are codified for the 2008 ozone NAAQS at 40 
CFR 51.1112. The EPA also proposed to codify the existing requirement 
under CAA section 172(c)(6) that, in addition to impacts of emissions 
from sources inside 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 to require such 
other measures for emissions reductions from these intrastate sources 
as needed to attain the ozone NAAQS by the applicable attainment date 
(see Section IV.C of this preamble). 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).
    b. Final Rule. The EPA is retaining our existing general RACM 
requirements for purposes of the 2015 ozone NAAQS, as codified at 40 
CFR 51.1312(c). 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.19 20 21

[[Page 63008]]

Further, the EPA requires that air agencies 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 if 
those measures are necessary for RFP. The EPA is retaining our existing 
general RACM requirements for the 2015 ozone NAAQS 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).
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    \19\ ``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).
    \20\ ``Guidance on the Reasonably Available Control Measures 
(RACM) Requirement and Attainment Demonstration Submissions for 
Ozone Nonattainment Areas,'' Memorandum from John S. Seitz, 
Director, OAQPS. November 30, 1999. Available at: https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/19991130_seitz_racm_guide_ozone.pdf.
    \21\ ``Additional Submission on RACM from States with Severe 
One-Hour Ozone Nonattainment Area SIPs,'' Memorandum from John S. 
Seitz, Director, OAQPS, December 14, 2000, available at: https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/20001214_seitz_additional_racm_submissions.pdf.
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    c. Comments and Responses. The EPA received no adverse comments on 
our proposal to retain our existing general RACM requirements for 
purposes of the 2015 ozone NAAQS. Our responses to comments regarding 
consideration of other measures for emissions reductions from 
intrastate sources under CAA section 172(c)(6) are provided in Section 
IV.C of this preamble.

G. CAA Section 182(f) NOX Exemption Provisions

1. Summary of Proposal
    The EPA proposed to retain our existing NOX exemption 
provisions under CAA section 182(f), which are codified for the 2008 
ozone NAAQS at 40 CFR 51.1113. These provisions would allow a person or 
an air agency to petition the Administrator for an exemption from 
NOX obligations for the 2015 ozone NAAQS under CAA section 
182(f) for any area designated nonattainment and for any area in an 
OTR. The EPA proposed that NOX exemptions granted for a 
previous ozone NAAQS would not apply to relieve an area from CAA 
section 182(f) NOX obligations under the 2015 standards.
2. Final Rule
    The EPA is finalizing our proposal to retain the existing 
NOX exemption provisions under CAA section 182(f) for 
purposes of the 2015 ozone NAAQS, as codified at 40 CFR 51.1313. 
NOX exemptions granted for any prior ozone NAAQS do not 
relieve an area from CAA section 182(f) NOX obligations 
under the 2015 ozone NAAQS. Consistent with current EPA policy, 
existing NOX exemptions for prior ozone standards remain 
valid for purposes of determining applicable requirements for 
implementing those prior standards.\22\
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    \22\ ``Guidance on Limiting Nitrogen Oxides (NOX) 
Requirements Related to 8-Hour Ozone Implementation,'' Memorandum 
from Stephen D. Page, Director, OAQPS, to Air Directors, Regions I-X 
(January 14, 2005), available at: https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/20050114_page_guidance_8-hr_ozone_nox_exemptions.pdf.
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3. Comments and Responses
    The EPA received no significant adverse comments regarding our 
proposal to retain our existing NOX exemption provisions 
under CAA section 182(f) for purposes of the 2015 ozone NAAQS.

H. General Nonattainment NSR Requirements

1. Summary of the Proposed Rule
    With one significant exception, the EPA proposed to retain our NNSR 
requirements contained at 40 CFR 51.165 and part 51 Appendix S, which 
include 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 
pertained to a proposal to address interprecursor trading (IPT) for 
meeting the offset requirement for ozone, which is discussed further in 
Section IV.D of this preamble.
2. Final Rule
    The EPA is adopting general NNSR requirements for the 2015 ozone 
NAAQS at 40 CFR 51.1314, as proposed. As explained in Section IV.D of 
this preamble, the EPA is restating our existing 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 of 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 establishing 
the 2015 ozone NAAQS. See 80 FR 65442 (October 26, 2015).
3. Comments and Responses
    The EPA received no significant adverse comments regarding our 
proposed general NNSR requirements. Please see Section IV.D of this 
preamble for comments related to the EPA restating our existing policy 
on ozone IPT.

I. Ambient Monitoring Requirements

    The EPA did not propose any changes to the existing ozone ambient 
monitoring requirements that 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 collects ambient air measurements in accordance 
with the enhanced monitoring requirements of CAA section 182(c)(1). The 
rulemaking for the final 2015 ozone NAAQS included revisions to the 
PAMS requirements at 40 CFR part 58 (80 FR 65416; October 26, 2015). 
The revisions were intended to provide a more spatially dispersed 
monitoring network, reduce potential redundancy and improve data value 
while providing monitoring agencies flexibility in collecting 
additional information needed to understand their specific ozone 
issues. The EPA received no adverse comments on the existing part 58 
ozone ambient monitoring requirements, and makes no changes to these 
existing requirements in this final rule.

J. Requirements for an OTR

1. Summary of Proposal
    The EPA proposed to retain our existing OTR requirements, and to 
add new deadline requirements for certain RACT SIP revisions (see 
Section IV.B 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.B of this 
preamble), the EPA proposed to retain the same requirements for the 
2015 ozone NAAQS, without revision.

[[Page 63009]]

2. Final Rule
    The EPA is finalizing the proposed OTR requirements. The adopted 
requirements for purposes of the 2015 ozone NAAQS are codified at 40 
CFR 51.1316.
3. Comments and Responses
    The EPA received no adverse comments specific to the proposed OTR 
requirements.

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

1. Summary of Proposal
    For the 2015 ozone NAAQS the EPA proposed to retain without 
revision our existing fee program SIP submission requirements for ozone 
nonattainment areas classified Severe or Extreme, which are codified 
for the 2008 ozone NAAQS in 40 CFR 51.1117.
2. Final Rule
    The EPA is finalizing the proposed requirements. The adopted fee 
program provisions, codified for the 2015 ozone NAAQS at 40 CFR 
51.1317, require states with ozone nonattainment areas classified 
Severe or Extreme to 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 an area's nonattainment designation. For 
nonattainment areas reclassified to Severe or Extreme from a lower 
classification after the date of their initial nonattainment 
designation, the EPA retains the ability to set an alternative deadline 
for the section 185 SIP submission, if appropriate, in the final action 
reclassifying the area. We anticipate that adjusting the section 185 
SIP submission deadline could be appropriate in situations where the 
reclassification action occurs on a date that is unreasonably near to 
or past the 10-year deadline applicable to areas initially designed 
Severe or Extreme.
3. Comments and Responses
    The EPA received no adverse comments on the proposed requirements.

L. Applicability

    The EPA proposed to retain the provision that establishes 
applicability of the current ozone NAAQS implementation provisions with 
respect to the prior ozone NAAQS, which is codified for the 2008 ozone 
NAAQS at 40 CFR 51.1119. This applicability provision states that the 
implementation provisions for the 2008 ozone standards (subpart AA of 
part 51) shall replace the implementation provisions for the previous 
1997 standards (subpart X of part 51) after revocation of the 1997 
NAAQS, except for anti-backsliding purposes. The EPA proposed to retain 
the same applicability provision for purposes of the 2015 ozone NAAQS, 
except that the proposed new implementation provisions (to be codified 
in 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.
    As discussed in Section II of this preamble, the EPA is not taking 
any final action regarding our approach for revoking a prior ozone 
NAAQS and establishing anti-backsliding requirements; the agency 
intends to address any revocation of the 2008 ozone NAAQS and any 
potential anti-backsliding requirements in a separate future 
rulemaking. As a result, we are not finalizing the proposed 
applicability provision discussed in this section at this time, which 
would be dependent on the particular approach that we take to any 
revocation action for 2008 ozone NAAQS that we may issue in the future.

M. International Transport

    Domestic ozone air quality can be influenced by emissions sources 
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,\23\ can affect to varying degrees the ability of some areas 
to attain and maintain the 2015 ozone NAAQS. The EPA continues to work 
with air agencies and other countries 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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    \23\ 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.
---------------------------------------------------------------------------

    In most areas in the U.S. with monitors that exceed the NAAQS, 
modeling studies demonstrate that the exceedances are due primarily to 
anthropogenic emissions sources within the U.S. However, Congress 
recognized the possibility that in some nonattainment areas the ability 
to attain the NAAQS may be impacted by emissions sources outside of the 
U.S., and through CAA section 179B (``International Border Areas''), 
Congress provided the EPA with the authority to address the impact of 
international emissions in areas designated nonattainment. 
Specifically, Congress provided that the EPA could 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 required 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 
need not apply for an extension of the ozone attainment dates pursuant 
to CAA section 181(a)(5), and is not subject to the stationary source 
fee program provisions of CAA section 185 and the mandatory 
reclassification provisions under CAA section 181(b)(2) \24\ for areas 
that fail to attain the ozone NAAQS by the applicable attainment date. 
Section 179B, thus, can be 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 affected area, 
emissions from outside of the U.S. prevent attainment.
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    \24\ The EPA's longstanding view is that CAA section 179B(b) 
contains an erroneous reference to section 181(a)(2), and that 
Congress actually intended to refer here to section 181(b)(2). See 
``State Implementation Plans; General Preamble for the 
Implementation of Title I of the Clean Air Act Amendments of 1990,'' 
57 FR 13498, 13569 n. 41 (April 16, 1992).
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1. Summary of Proposal
    The EPA proposed a requirement that all demonstrations under CAA 
section 179B(b), regardless of an area's

[[Page 63010]]

classification (including nonattainment areas classified as Marginal), 
must include a showing that the air agency has adopted all RACM, 
including RACT, for the area in accordance with CAA section 172(c)(1), 
42 U.S.C. 7502(c)(1). We also asked for comment on whether the 
opportunity for air agencies to submit demonstrations under CAA section 
179B 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 geographic limitation. The proposal noted that the 
science review supporting the 2015 ozone NAAQS suggested that the 
influence of international sources on U.S. ozone levels will be largest 
in locations near the borders of Mexico or Canada (80 FR 65292, 65444; 
October 26, 2015) and that, historically, only states with 
nonattainment areas in the immediate vicinity of the Mexican border 
have submitted CAA section 179B demonstrations to the EPA (81 FR 81303; 
November 17, 2016).
2. Final Rule
    The EPA is not finalizing our proposed requirement that all 
demonstrations under CAA section 179B(b) must include a showing that 
the air agency adopted all RACM, including RACT.
    The EPA is choosing to not adopt our proposal for this final rule 
because the Act does not require states to implement RACM/RACT in 
Marginal ozone nonattainment areas. For purposes of CAA section 179B 
demonstrations for the 2015 ozone NAAQS, we are maintaining the 
approach used for prior ozone standards that only areas classified 
Moderate and higher must show that they have implemented RACM/RACT.
    In the proposal, the EPA also solicited comment on whether--but did 
not propose that--demonstrations under CAA section 179B should be 
limited only to nonattainment areas adjoining international borders. 
After considering comments received, we are not adopting any geographic 
limitation on the use of CAA section 179B for purposes of the 2015 
ozone NAAQS. We are instead clarifying that a demonstration prepared 
under CAA section 179B could consider emissions emanating from North 
American or intercontinental sources and is not restricted to areas 
adjoining international borders, consistent with the approach 
articulated in the preamble of the 2008 Ozone NAAQS SIP Requirements 
Rule.
    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. In addition, the 
EPA is currently developing supplementary technical information and 
guidance to assist air agencies in preparing demonstrations that meet 
the requirements of CAA section 179B.
3. Comments and Responses
    Comment: The EPA received numerous comments on our proposed RACM/
RACT requirement for all demonstrations under CAA section 179B(b) 
(including for Marginal areas), and providing feedback on whether CAA 
section 179B applicability should be limited to nonattainment areas 
adjoining international borders. There was broad objection to both 
approaches, which many commenters interpreted as restricting the 
potential use of CAA section 179B for attainment plans under the 2015 
ozone NAAQS.
    Response: As discussed previously, the EPA is not interpreting CAA 
section 179B as requiring that demonstrations under CAA section 179B(b) 
for Marginal areas include a showing that the air agency adopted all 
RACM, including RACT. We are also finalizing our existing approach that 
does not restrict the use of CAA section 179B demonstrations to areas 
adjoining international borders.
    Comment: Several commenters supported the proposed RACM/RACT 
requirement for all demonstrations under CAA section 179B(b). One 
commenter stated that CAA section 179B does not alter the subpart 1 
requirement in CAA section 172(c)(1) that all SIPs provide for 
implementation of RACM/RACT as expeditiously as practicable. The same 
commenter also argued that failure to require RACM/RACT for Marginal 
areas seeking relief under CAA section 179B would upset the subpart 2 
scheme for reclassification and implementation of basic reasonable 
control measures, and prevent attainment of the NAAQS as expeditiously 
as practicable.
    Response: The EPA is not finalizing our proposed requirement that 
all demonstrations under CAA section 179B(b) must include a showing 
that the air agency adopted all RACM, including RACT. The Act does not 
require implementation of RACM/RACT in Marginal ozone nonattainment 
areas under the relevant implementation provisions in subpart 2, and 
nothing in 179B alters the statutory requirements with respect to RACM/
RACT obligations in subpart 2. The EPA believes the CAA's specific 
provisions for ozone Marginal areas in section 182(a) rather than 
general nonattainment provisions in section 172(c)(1) prescribe the 
specific SIP revision requirements for such areas. In section 182(a), 
the CAA states ``Each state [with a Marginal area] shall . . . submit 
to the Administrator the state implementation plan revisions (including 
the plan items) described under this subsection . . .'' (emphasis 
added). Subsection 182(a) does not list RACM/RACT as a plan item. This 
is in clear contrast to the provisions in subsection 182(b) for 
Moderate and higher classified areas, which identifies specific RACT 
requirements (e.g., section 182(b)(2)) and plan submissions that 
``provide such specific annual reductions in emissions . . . as 
necessary to attain . . .'' For this final rule, we are adopting our 
existing approach grounded in the plain language of CAA section 
179B(b), which applies specifically to the ozone NAAQS and does not 
explicitly modify the subpart 2 planning requirements in CAA section 
182 to require RACM/RACT for Marginal areas.

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

    For purposes of implementing the 2015 ozone NAAQS, we are 
promulgating several regulatory provisions that are similar to the 
corresponding implementation provisions for the 2008 ozone NAAQS, but 
with modifications to reflect application to the 2015 ozone NAAQS, as 
explained later. The existing implementation provisions for the 2008 
standards are codified at subpart AA of 40 CFR part 51, and the 
corresponding provisions for the 2015 standards will now be codified at 
subpart CC of part 51. The revised provisions for the 2015 standards 
address SIP requirements pertaining to MCD for RFP; the submission and 
implementation deadlines for RACT SIP revisions; the consideration of 
intrastate pollution sources outside of a nonattainment area for 
attainment planning purposes;

[[Page 63011]]

NNSR IPT for ozone; and emissions inventories and emissions statements.

A. Requirements for RFP: Milestone Compliance Demonstrations

    The EPA proposed to revise our 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 RFP 
regulatory provisions for the 2008 ozone NAAQS characterize the 
emissions reductions and time intervals that constitute RFP milestones, 
but do not address the requirements for demonstrating compliance with 
these milestones.
    CAA section 182(g)(1) requires that states demonstrate whether 
nonattainment areas classified Serious, Severe or Extreme have achieved 
incremental RFP emission reductions needed to ensure attainment of the 
NAAQS by the prescribed applicable 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 established in the general RFP requirements of CAA 
sections 182(c)(2)(B) for Serious areas. Sections 182(d) and 182(e) 
incorporate those requirements for, respectively Severe and Extreme 
areas. Accordingly, the timeline for Serious areas provided in section 
182(c)(2)(B) also applies to Severe and Extreme areas.
    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 applicable milestone date. Section 182(g) 
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 a 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.
1. Summary of Proposal
    The EPA proposed 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 regulatory requirements for fine particulate matter 
(PM2.5), which were added in the 2016 final implementing 
regulations for the PM2.5 NAAQS.\25\ The EPA also considered 
the amount of time allowed in the statute for states to make the 
required submittal.
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    \25\ See ``Fine Particulate Matter National Ambient Air Quality 
Standards: State Implementation Plan Requirements'' 81 CFR 58063-64; 
August 24, 2016), hereafter PM2.5 SIP Requirements Rule.
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2. Final Rule
    The EPA is finalizing MCD requirements for RFP as proposed. These 
requirements, codified at 40 CFR 51.1310(c), are consistent with the 
PM2.5 SIP Requirements Rule.\26\ Similar to the statutory 
requirements for ozone, CAA section 189(c)(1) establishes a 3-year 
cycle for PM2.5 milestones. For both pollutants, the CAA 
provides Administrator discretion in setting the form and content of 
the milestone demonstration submittal.\27\
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    \26\ See id.
    \27\ 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 applicable milestone date, 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 
must also demonstrate that all measures in the SIP have been 
implemented.
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    The PM2.5 SIP Requirements Rule requires that the 
quantitative milestones be constructed 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.\28\
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    \28\ 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 41998 at 42016; August 16, 1994).
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    The EPA is adopting a similar approach for MCDs for the 2015 ozone 
NAAQS. We interpret CAA sections 182(g)(1) and 182(g)(2) as imposing 
two separate obligations on an air agency: (1) To determine whether an 
affected nonattainment area has achieved an incremental emissions 
reduction corresponding with the RFP milestone; and (2) to demonstrate 
to the satisfaction of the Administrator that the RFP milestone has 
been met. 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), because the approach is 
grounded in SIP provisions that correlate control measures and 
resulting emissions reductions. As an alternative, an air agency could 
rely on periodic, triennial emissions inventory data for demonstration 
purposes where the appropriate data are obtainable within the 90-day 
MCD submittal timeframe.\29\ In all cases, 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).
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    \29\ Triennial emissions reporting periods are set by regulation 
in the AERR at 40 CFR part 51, subpart A. The most recent and 
upcoming reporting years are 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. As discussed in Section IV.E of this 
preamble, the adopted regulations for the 2015 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 51.1315(b).
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    We are providing additional guidance on the MCD submission process 
in this final rule. Consistent with the EPA's process for 
PM2.5 quantitative milestones, the EPA believes it would be 
appropriate for MCD to be submitted from the Governor or Governor's 
designee to the Regional Administrator of the respective EPA Regional 
office serving the submitting state. The EPA will notify the state of 
our determination (regarding whether or not the state's demonstration 
is adequate) by sending a letter to the appropriate

[[Page 63012]]

Governor or Governor's designee or, alternatively, by publishing a 
notice in the Federal Register. The EPA encourages states to submit 
MCDs, including supporting documents, through the agency's electronic 
SIP submission system \30\ in order to simplify the process and reduce 
resource burden on all sides. The EPA believes it is consistent with 
statutory requirements to not consider MCDs to be formal SIP revisions 
subject to CAA public notice and comment requirements.
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    \30\ State Planning Electronic Collaboration System (SPeCS) for 
SIPs. For more information see https://www.epa.gov/air-quality-implementation-plans/submit-sips-online.
---------------------------------------------------------------------------

3. Comments and Responses
    Comment: One commenter argued that an ``actual emissions 
reductions'' approach using emissions inventory data is the only lawful 
and rational approach for demonstrating RFP milestone compliance. 
Because the Act defines RFP baseline emissions in terms of actual VOC 
or NOX emissions (see CAA section 182(b)(1)(B)), the 
commenter contended that RFP can only be satisfied by actual emission 
reductions. This interpretation, they claimed, is supported by the 
CAA's legislative history and the EPA's General Preamble. Further, the 
commenter notes that RFP must address ``any growth in emissions after'' 
the baseline year (see CAA sections 182(b)(1)(A)(i) and 182(c)(2)(B)) 
and, therefore, only actual emissions would be sufficient to gauge 
compliance with an RFP baseline.
    Response: The EPA disagrees with the commenter that actual 
emissions reductions are the only possible basis for demonstrating RFP 
milestone compliance under CAA section 182(g). For PM2.5, 
the statute requires quantitative milestones that demonstrate RFP, 
whereas for ozone CAA section 182(g)(1) uses the term ``applicable 
milestone'' to refer to the required RFP emissions reduction. However, 
CAA section 182(g)(2) specifically provides the Administrator the 
authority and discretion to establish the ``form and manner'' of MCDs, 
and the EPA is exercising this authority and discretion through the 
regulations adopted in this final rule. We encourage air agencies to 
work with their EPA Regional office to develop a MCD suitable for the 
specific facts and circumstances of the attainment plan for a 
particular area (addressing, as appropriate, the potential emissions 
growth noted by the commenter), which provides an objective means to 
measure RFP.
    Comment: Two commenters supported the EPA's proposed MCD 
requirements and urged the agency to issue related guidance. One of the 
commenters noted that the proposed MCD regulations were silent on the 
form and manner of submittal, and requested that the EPA clarify who is 
required to submit the MCD, whether the submission is considered a SIP 
revision, and whether public notice would be required for the MCD. The 
same commenter further requested that the EPA clarify whether 
historical emissions inventory data can be used for MCDs where the 
required RFP reduction was achieved in advance of the applicable 
milestone date.
    Response: The EPA has provided additional guidance on the MCD 
submission process in this final rule preamble, as explained earlier, 
and intends to develop more detailed guidance for preparing RFP MCD for 
ozone and PM2.5. Regarding the use of historical emissions 
inventory data in MCDs, we believe our adopted MCD requirements would 
accommodate this approach, so long as the MCD submission provided a 
sufficiently objective means for evaluating the area's progress toward 
attainment, consistent with the statutory requirements of CAA section 
182(g).

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

    The EPA proposed new RACT SIP revision submission and 
implementation deadlines for specific kinds of triggering events that 
may occur after the EPA has initially designated areas under a revised 
ozone NAAQS. The RACT provisions established in the 2008 Ozone NAAQS 
SIP Requirements Rule address RACT SIP revision submission and 
implementation deadlines for areas (including portions of a state 
located in an OTR) subject to initial designation and existing RACT 
requirements, including requirements described in existing CTGs. CAA 
section 182(b)(2) establishes that a state shall submit a SIP revision 
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 
from the enactment date of the 1990 CAA Amendments). As codified for 
the 2008 ozone NAAQS at 40 CFR 51.1112, the EPA interpreted this CAA 
timeframe to require submittal of RACT SIP revisions 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. 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 submissions and 
implementation. For voluntary reclassifications, CAA section 181(b)(3) 
does not establish a precise timeframe for submitting SIP revisions. 
The EPA's general practice is to establish SIP revision submission 
deadlines as part of the action granting an air agency's request for 
voluntary area reclassification.
    The EPA is retaining these general RACT provisions for purposes of 
the 2015 ozone NAAQS, based on the rationale articulated in the final 
2008 Ozone NAAQS SIP Requirements Rule (see Section III.F of this 
preamble). However, the existing RACT provisions do not specify 
deadlines for some RACT SIP revision submittal and implementation 
requirements triggered by events occurring after initial area 
designations, including area reclassifications and the issuance of new 
CTGs. The following sections address the RACT submittal and 
implementation deadlines for these post-designation scenarios.
1. RACT SIP Revision Submittal and Implementation Deadlines for Newly 
Reclassified Areas
    a. Summary of Proposal. The EPA proposed default submission and 
implementation deadlines for SIP revisions resulting from area 
reclassifications that occur after initial area designations under an 
ozone NAAQS.\31\ This includes mandatory reclassification to a higher 
classification upon failure to attain (pursuant to CAA section 
181(b)(2)) and voluntary reclassification to a higher classification 
upon an air agency's request (pursuant to CAA section 181(b)(3)). We 
proposed that, following a reclassification action, RACT SIP revisions 
be submitted no later than 24 months after the effective date of 
reclassification, or by an alternative deadline established by the 
Administrator as part of the action

[[Page 63013]]

reclassifying an area. We proposed that the RACT SIP revisions be 
implemented as expeditiously as practicable, but no later than the 
start of the attainment year ozone season 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 
also proposed that the Administrator would retain existing authority to 
establish a different implementation deadline as part of the action 
reclassifying an area. This proposed approach would apply to 
nonattainment area reclassifications.
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    \31\ For purposes of this preamble discussion, 
``reclassification'' is assumed to encompass nonattainment areas 
being reclassified to a higher classification, attainment areas 
being redesignated as nonattainment and assigned an initial 
classification of Moderate or higher, 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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    b. Final Rule. The EPA is finalizing the proposed deadlines with 
clarifications, as codified at 40 CFR 51.1312(a)(2) and (3). To address 
reclassification scenarios, we are adopting default submission and 
implementation deadlines for resulting SIP revisions. Following a 
reclassification action, RACT SIP revisions must be submitted no later 
than 24 months after the effective date of reclassification, or by an 
alternative deadline established by the Administrator as part of the 
action reclassifying an area. RACT SIP revisions must be implemented as 
expeditiously as practicable, but no later than the start of the 
attainment year ozone season 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 clarifying 
that the term ``ozone season attainment year'' used in the preamble to 
the proposed rulemaking should read ``attainment year ozone season'' as 
correctly presented in the proposed regulatory definition at 40 CFR 
51.1300(i). The Administrator retains authority to establish different 
RACT SIP revision submission and implementation deadlines as part of 
the action reclassifying an area.
    We are also in this final rule clarifying the implementation 
deadline for RACT SIP revisions triggered by reclassification actions 
that occur after initial area designations. As presented in the 
preamble to the proposed rulemaking, these RACT SIP revisions must be 
implemented as expeditiously as practicable, but no later than the 
start of the attainment year ozone season associated with the area's 
new attainment deadline, or January 1 of the third year after the 
associated SIP revision submission deadline, whichever is earlier. The 
Administrator also has the authority to establish a different 
implementation deadline as part of the reclassification action (81 FR 
81293; November 17, 2016). The proposed regulatory text in 40 CFR 
51.1312(a)(3)(ii) incorrectly omitted the alternative implementation 
deadline--i.e., it omitted the phrase ``start of the attainment year 
ozone season associated with the area's new attainment deadline''--and 
we have added this language to the final rule regulatory text, 
consistent with the discussion in the preamble to the proposed 
rulemaking. These default deadlines are grounded in the construct of 
the overall RACT SIP revision submission and implementation timeframe 
articulated in section 182(b)(2) of the CAA, and are also intended to, 
where possible, provide at least one full ozone season in advance of an 
area's maximum attainment date for implemented controls to achieve 
emission reductions.
    c. Comments and Responses. Comment: Several commenters expressed 
the general concern that the default timelines would not provide 
sufficient time for submission and/or implementation of RACT SIP 
revisions triggered by reclassification actions, with some commenters 
suggesting that air agencies should have 3 years to prepare and submit 
the required SIP revision. Another commenter said that the EPA should 
not establish RACT deadlines more stringent than those for similarly 
classified areas, and that it should be a state's responsibility to 
determine what is ``as expeditiously as practicable'' as it relates to 
the schedule for submitting its required SIP revision.
    Response: The EPA acknowledges the commenters' general concern that 
mandatory reclassification actions can limit the time available to 
submit and implement required RACT SIP revisions, but emphasizes that 
CAA section 182(i) does not allow the EPA to extend the maximum 
attainment date corresponding with an area's new classification. We 
have noted this statutory constraint previously in establishing the SIP 
revision submission deadline for nonattainment areas reclassified to 
Moderate after failing to attain the 2008 ozone NAAQS by the Marginal 
attainment date of July 20, 2015. In the face of the impending Moderate 
area attainment date (July 20, 2018), the EPA exercised our authority 
under CAA section 182(i) to set a uniform SIP submission deadline for 
affected areas at the latest date compatible with the RACT 
implementation deadline for Moderate areas (81 FR 26699; May 4, 
2016).\32\
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    \32\ That latest compatible date for the 2008 ozone NAAQS was no 
later than January 1 of the 5th year after the effective date of 
designation for the NAAQS, i.e., January 1, 2017.
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    Our adopted requirements are intended to maximize planning 
flexibility within the fixed outer bound of an area's maximum 
attainment date, by retaining the Administrator's discretion under CAA 
section 182(i) to set alternative RACT SIP submission and 
implementation deadlines where appropriate. This discretion could 
potentially apply to the extended submission and implementation 
deadlines suggested by some commenters, though the degree of 
flexibility would be dictated by the available compliance timeframe, 
bounded by a reclassified area's maximum attainment date. For example, 
an air agency that anticipates an area will not timely attain can 
request a voluntary reclassification under CAA section 181(b)(3), which 
would provide more time and potential flexibility for required RACT SIP 
submissions and implementation than would a later mandatory 
reclassification under CAA section 181(b)(2) upon actual failure to 
attain.
    At the same time, the EPA believes it is important to provide 
default submission and implementation deadlines grounded in our overall 
approach for RACT SIP revisions outlined in CAA section 182(b), in the 
event that the Administrator does not exercise his or her discretion to 
set alternative deadlines in a reclassification action. Regarding the 
comment that the EPA should not establish RACT deadlines more stringent 
than those for similarly classified areas, we disagree and note that 
(particularly for mandatory reclassification actions) the Administrator 
cannot alter the reclassified area's maximum attainment date, which 
necessarily provides a shorter RACT SIP timeframe than for areas 
initially assigned the same classification. The EPA disagrees with the 
comment that it should be a state's responsibility to determine what is 
``as expeditiously as practicable'' as it relates to the schedule for 
submitting their required SIP revision. The language of CAA section 
182(b)(2) clearly establishes the statutory basis for RACT SIP 
submission deadlines, while qualifying that the SIP revisions shall 
provide for implementation of required measures as expeditiously as 
practicable, but not later than a date that the EPA interprets relative 
to the Moderate area attainment date.
    Comment: A commenter remarked that the proposed default deadlines 
for RACT SIP revisions triggered by reclassification actions could 
result in implementation deadlines occurring after a reclassified 
area's maximum attainment date. The commenter provided an example 
scenario where a

[[Page 63014]]

nonattainment area initially classified as Marginal (e.g., in 2017) 
fails to attain by the Marginal attainment date (in 2020) and is 
reclassified to Moderate (in 2021), with its RACT SIP submission due 2 
years later (in 2023). The commenter goes on to illustrate how applying 
a default RACT implementation deadline of no later than January 1 of 
the third year after the associated SIP revision submission deadline 
would place that default implementation deadline later than the 2023 
attainment date for Moderate areas. The commenter noted it was 
arbitrary and unlawful for the EPA to propose default deadlines that 
contravene statutory structure in this manner.
    Response: The EPA disagrees with the commenter that our default 
submission and implementation deadlines for RACT SIP revisions 
triggered by area reclassifications contravene the CAA. The default 
submission deadline of no later than 24 months after the effective date 
of reclassification is grounded in our longstanding interpretation of 
the RACT SIP submission timeframe in CAA section 182(b)(2). As 
discussed previously, we are clarifying and adopting in this final rule 
our proposed default implementation deadline that requires RACT SIP 
revisions to be implemented as expeditiously as practicable, but no 
later than the start of the attainment year ozone season associated 
with the area's new attainment deadline, or January 1 of the third year 
after the associated SIP revision submission deadline, whichever is 
earlier. The EPA agrees with the commenter that applying the latter 
implementation deadline (i.e., January 1 of the third year after the 
associated SIP revision submission) would exceed the area's maximum 
attainment date in the commenter's Marginal-to-Moderate hypothetical 
mandatory reclassification scenario. We note, however, that the earlier 
alternative default deadline (i.e., implementation by the start of the 
attainment year ozone season) would instead apply in this case, and 
would be compatible with the RACT implementation occurring before the 
area's attainment date passes. In the case where an air agency requests 
a voluntary reclassification beyond a single level (e.g., Marginal to 
Serious or Moderate to Severe),\33\ the earlier default implementation 
deadline could potentially be January 1 of the third year after the 
associated SIP revision submission. This approach is compatible with 
the statutory requirement for areas initially classified Serious and 
higher, which must implement RACT no later than January 1 of the fifth 
year after the effective date of designation (i.e., the attainment year 
for Moderate areas), and are thus afforded additional time for 
implemented controls to achieve emission reductions.
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    \33\ For example, the state of California requested and was 
granted voluntary reclassifications beyond a single level for 
several nonattainment areas for the 1997 ozone NAAQS (see 81 FR 
81285; November 17, 2016).
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2. RACT SIP Revision Submittal and Implementation Deadlines Associated 
With New Control Techniques Guidelines
    a. Summary of Proposal. The EPA proposed two approaches for 
establishing submission and implementation deadlines for SIP revisions 
triggered by new CTGs issued by the EPA after the promulgation of 
initial area designations under a revised ozone NAAQS. Under the first 
approach, we proposed 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, and that RACT SIP revisions must be implemented no later than 
January 1 of the third year after the associated SIP revision 
submission deadline. Under the second approach, we also articulated the 
Administrator's authority to establish a deadline for implementing RACT 
SIP revisions as part of the action issuing a new CTG. These proposed 
approaches would apply to covered sources in nonattainment areas and 
portions of a state located in an OTR subject to new RACT SIP 
obligations.
    b. Final Rule. The EPA is finalizing a combination of the proposed 
approaches, as codified at 40 CFR 51.1312(a)(2) and (3). For CTGs 
issued between November 15, 1990, and the date of attainment, CAA 
section 182(b)(2) requires a state to submit the associated RACT SIP 
revision, where applicable, within the timeframe established by the 
Administrator in issuing the CTG. The EPA interprets this provision as 
authorizing the Administrator to set a SIP submission deadline in the 
action issuing any future CTG. However, the agency is also establishing 
a default submission deadline of no later than 24 months after the 
effective date of the action issuing the CTG, which is grounded in our 
overall approach for RACT SIP revisions outlined in CAA section 182(b), 
in the event that the Administrator does not set an alternative 
submission deadline as part of a CTG action.
    While CAA section 182(b)(2) addresses the submission requirements 
for RACT SIP revisions triggered by new CTGs, the CAA is otherwise 
silent regarding the schedule for implementation of those 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 to any portion of a state located in an OTR. For CTGs in 
effect at the time of initial area designations for a revised NAAQS, 
the EPA has interpreted the relevant 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 RACT SIP revisions triggered by new CTGs 
issued after initial area designations, we are adopting the proposed 
default implementation deadline of no later than January 1 of the third 
year after the associated SIP revision submission deadline. We 
anticipate that this adopted default implementation deadline will 
provide an overall RACT schedule similar to that for sources subject to 
CTG requirements upon initial area designations.
    We are also articulating in this final rule the Administrator's 
authority to establish an alternative to the default deadline for 
implementing RACT SIP revisions, as part of the action issuing a new 
CTG. Under this option, setting a RACT SIP revision implementation 
deadline as part of 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 and the overall attainment schedule. The adopted 
approaches for establishing RACT SIP submission and implementation 
deadlines would apply to covered sources in nonattainment areas and 
portions of a state located in an OTR subject to new RACT SIP 
obligations.
    c. Comments and Responses. Comment: Several commenters stated that 
a default submission deadline is not necessary for RACT SIP revisions 
triggered by the issuance of a CTG after initial area designations. 
They noted that the CAA expressly authorizes the Administrator to set a 
RACT SIP submission deadline as part of the related CTG document, and 
that a default deadline is either redundant or

[[Page 63015]]

could be interpreted to restrict the Administrator's authority.
    Response: The EPA agrees with commenters that CAA section 182(b)(2) 
authorizes the Administrator to set a RACT SIP submission deadline as 
part of the related CTG document. As discussed previously, CAA section 
182(b)(2) expressly requires that states submit RACT SIP revisions 
triggered by new CTG issuance within a period established by the 
Administrator, and we interpret this provision to authorize--but not 
require--the Administrator to set a RACT SIP submission deadline in the 
action issuing the CTG. As a result, we are adopting the proposed 
default SIP submission deadline of no later than 24 months after the 
effective date of the action issuing the CTG, in addition to affirming 
in this final rule the Administrator's existing authority to set an 
alternative RACT SIP submission deadline as part of the action issuing 
the CTG.

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

1. Summary of Proposal
    As discussed in Section III.F.2 of this preamble, the EPA proposed 
to require that, for each nonattainment area for which an attainment 
demonstration is required (see Section III.D 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. The EPA further proposed to codify the existing 
requirement under CAA section 172(c)(6) 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 control 
measures on these intrastate sources if doing so is necessary to 
provide for attainment of the applicable ozone NAAQS within the area by 
the applicable attainment date. This proposed rulemaking provision is 
consistent with SIP elements required under the CAA, as well as 
existing EPA interpretations of CAA section 172(c)(6) as articulated in 
previous NAAQS implementation rulemakings.
2. Final Rule
    The EPA is finalizing the requirement regarding consideration of 
``other control measures'' for intrastate sources of pollution, as 
proposed. CAA section 172(c)(6) requires that SIP provisions include 
enforceable emission limitations and other control measures, means or 
techniques as may be necessary or appropriate 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 emissions source within the 
state's jurisdiction, including those outside of a nonattainment area. 
Upwind sources within a state may have a significant impact on air 
quality in a downwind nonattainment area, and failure to consider and 
require, as appropriate, reasonable control measures for these sources 
may preclude attainment of a NAAQS by the attainment date. Though not 
directly a part of a nonattainment area RACM analysis, the EPA has 
addressed this ``other control measures'' provision in the preamble 
discussions for previous NAAQS implementation rulemakings,\34\ and for 
clarity is codifying this interpretation in this final rule at 40 CFR 
51.1312(c). As discussed in Section III.F of this preamble, the EPA is 
otherwise adopting all RACM requirements for purposes of the 2015 ozone 
NAAQS, based on the rationale and approach articulated in the final 
2008 Ozone NAAQS SIP Requirements Rule.
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    \34\ See the Phase 2 proposed rulemaking (68 FR 32829; June 2, 
2003) and 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).
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3. Comments and Responses
    Comment: A number of commenters opposed the EPA's interpretation of 
CAA section 172(c)(6) as applying to emissions sources outside of 
designated nonattainment areas. As one commenter stated, the plain 
language of CAA section 172 in general focuses its discussions and 
references to sources within a designated nonattainment area, and makes 
no mention of requiring emission reductions for sources outside the 
nonattainment area.
    Response: The EPA disagrees with the commenters concerning the 
proper application of CAA section 172(c)(6). Unlike other SIP 
requirements under CAA section 172(c)(1), such as RACM/RACT-level 
controls on sources located in a nonattainment area, CAA section 
172(c)(6) is not limited by its terms to sources located in the 
nonattainment area. Upwind sources within a state may have a 
significant impact on air quality in a nonattainment area, and CAA 
section 172(c)(6) imposes a potential obligation upon states to impose 
emission controls on sources located outside a designated nonattainment 
area that are in addition to, and beyond those, otherwise required on 
sources located the nonattainment area, if necessary or appropriate for 
purposes of attainment by the attainment date.
    Comment: Some commenters contended that emissions from sources 
outside a nonattainment area, if nearby and affecting a nonattainment 
area's ability to timely attain, should be accounted for in setting 
nonattainment area boundaries as part of the designations process under 
CAA section 107(d).
    Response: The EPA agrees with commenters that a designated 
nonattainment area should already include the nearby sources that, at 
the time of designations, were determined to be contributing to 
violations in the area. But we disagree that the designations process 
under CAA section 107(d) is the exclusive approach for identifying 
relevant contributing sources for a nonattainment area, as there may be 
additional contributing sources within a state that were not 
sufficiently ``nearby'' the area, or were otherwise not identified in 
the nonattainment area designations process as contributing to 
violations in the area. Consistent with our existing policy, the EPA 
interprets CAA section 172(c)(6) as imposing a separate obligation to 
consider and control sources located outside of a nonattainment area 
but within a state's jurisdiction, if necessary or appropriate to 
attain a standard by the applicable attainment date.
    Comment: Multiple commenters interpreted the EPA's proposal as 
imposing a mandatory requirement for states to consider and implement 
emission controls for intrastate sources located outside of a 
designated nonattainment area. Some commenters characterized the 
proposal as requiring RACM outside a nonattainment area, where other 
commenters requested that we further clarify a state's discretion, 
under CAA section 172(c)(6), to consider and require ``other control 
measures'' for sources located outside of a nonattainment area.
    Response: The EPA believes our interpretation of CAA section 
172(c)(6), under certain circumstances, establishes a mandatory 
requirement for states to consider and implement emission controls for 
sources inside the state but outside of a designated nonattainment 
area. The language of the statute, and our adopted regulatory text in 
40 CFR 51.1312(c), describe a conditional requirement for placing 
controls such sources, i.e., states are required to impose controls on 
sources located outside of a nonattainment area but

[[Page 63016]]

within the state's jurisdiction, only in circumstances where that is 
necessary or appropriate to provide for attainment by the attainment 
date, because the emission controls required on sources within the 
nonattainment area are not sufficient to provide for attainment by that 
date. This qualification indicates that the obligation is tied to the 
attainment needs of the nonattainment area in question and does not 
apply more broadly. Further, the EPA emphasizes that we do not 
interpret section 172(c)(6) to automatically require states to conduct 
an evaluation of all sources and all potential controls throughout the 
entire state regardless of attainment needs. However, if necessary to 
achieve attainment by the applicable attainment date, the EPA believes 
the CAA obligates states to place emission controls on significant 
emissions sources elsewhere within the state as needed to achieve the 
necessary reductions.

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

1. Summary of Proposal
    In response to a petition for reconsideration granted on November 
5, 2015, the EPA proposed to reaffirm our longstanding policy regarding 
IPT for ozone, which is currently codified at 40 CFR 51.165(a)(11) and 
part 51 Appendix S, section IV.G.5,\35\ by re-proposing the existing 
regulatory provisions with revised text, and adding specific criteria 
for developing and implementing an IPT program.\36\ In addition, the 
EPA indicated that the re-proposed IPT provision, when finalized, would 
supersede any previous ozone IPT policy articulated in earlier EPA 
guidance.\37\ Further, the November 17, 2016, proposal explained that 
the EPA proposed no other changes to the existing requirements in the 
NNSR regulations.\38\
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    \35\ The EPA originally added these provisions specific to ozone 
to the NNSR regulation in 2015 as part of the final 2008 Ozone NAAQS 
SIP Requirements Rule. See 80 FR 12264 at 12288.
    \36\ See 81 FR at 81295-8.
    \37\ 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, as finalized through this rulemaking, supersedes the 
information contained in that earlier document specifically with 
respect to IPT.
    \38\ In the proposal, the EPA did not propose to change or seek 
comment on any existing NNSR emissions offsets requirements 
contained in the NNSR regulations at 40 CFR 51.165 and part 51 
Appendix S. Existing NNSR emissions 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.
---------------------------------------------------------------------------

    The proposal noted the EPA's continued interpretation that the CAA 
accommodates the use of technically supported IPT to satisfy the NNSR 
offset requirement. As discussed in greater detail in the Comments and 
Responses section that follows, the EPA stated at proposal that the CAA 
allows the total annual tonnage of emissions of one ozone precursor to 
be offset by reductions in total actual annual emissions of another 
ozone precursor (in units of tons per year (tpy)) pursuant to an IPT 
ratio that shows the reductions will have an equivalent or greater air 
quality benefit. The proposal explained that the authority to permit 
IPT is based on the language of section 173(c)(1) of the CAA and the 
definition of ``air pollutant'' in section 302(g) of the CAA, and that 
ozone is the regulated pollutant at issue (rather than NOX 
or VOC, which are both recognized precursors to the formation of 
ground-level ozone concentrations).
    The EPA proposed that states interested in implementing an ozone 
IPT program must submit the following to the EPA as part of a plan for 
approval: (1) IPT provision(s), including area-specific default IPT 
ratio(s),39 40 where applicable; (2) a description of the 
air quality model(s) used to develop any default IPT ratio(s); and (3) 
an accompanying modeling demonstration showing that such ratio(s) 
provide an equivalent or greater air quality benefit with respect to 
ground level ozone concentrations in the ozone nonattainment area than 
an offset of the emitted precursor would achieve.
---------------------------------------------------------------------------

    \39\ An IPT ratio sets the appropriate proportion for the 
amounts of each precursor in tpy of emissions, which is intended to 
ensure that the substitution of one ozone precursor for another in 
an offset transaction provides an equivalent or greater air quality 
benefit with respect to ground level ozone concentrations in the 
ozone nonattainment area. The IPT ratio is separate and distinct 
from the statutory offset ratios contained in the CAA that are 
directly associated with area classifications for ozone 
nonattainment areas. See e.g., CAA Section 182(b)(5) (establishing 
an offset ratio of 1.15 to 1 for Moderate areas). Both ratios must 
be applied in determining the appropriate emissions offset that must 
be applied for a particular offset transaction if one ozone 
precursor is being used to offset a different ozone precursor. An 
example of a simple offset calculation with the application of an 
IPT ratio would be a major NNSR proposed source in a Moderate area 
seeking to offset a 200 tpy NOX increase with reductions 
in VOC from another source or the respective SIP approved Emission 
Reduction Credit Bank. First, the 200 tpy NOX offset is 
subject to the 1.15 Moderate area offset ratio, then the product is 
multiplied by the IPT ratio (either area-wide or case-specific 
derived from technical demonstration). If we assume the IPT ratio in 
this case is 5, the resulting equation is: (200 tpy NOX) 
x (1.15(Moderate area offset ratio)) x (5 VOC/
NOX (IPT ratio applied)) = 1,150 tpy total NOX 
(offset) required for NNSR permitting purposes.
    \40\ Hereafter referred to as default IPT ratio(s) or default 
ratio(s).
---------------------------------------------------------------------------

    The EPA recommended that each air agency implementing an IPT 
program consult with the appropriate EPA Regional office as the air 
agency develops a modeling protocol to establish a default IPT ratio or 
ratios \41\ for a nonattainment area. The EPA sought comments on the 
proposed contents of the plan submission and the approach for 
establishing any default IPT ratios.
---------------------------------------------------------------------------

    \41\ The draft Technical Guidance Document provided in the 
docket supports the division of a nonattainment area into sub-areas 
with a technical demonstration substantiating the need for separate 
ratios in specific portions of a nonattainment area.
---------------------------------------------------------------------------

    When the EPA published our NNSR implementation rules for 
PM2.5 in 2008, we indicated that, while the new 
implementation rules allowed air agencies to adopt IPT programs to 
satisfy the NNSR offset requirements for PM2.5, such IPT was 
not permissible for netting purposes. See 73 FR 28340 (May 16, 2008). 
Consistent with that policy, in the proposal the EPA proposed that an 
IPT program could not be used for purposes of netting under the NNSR 
program.
    The EPA also indicated in the proposal that we have interpreted the 
CAA to preclude the use of ozone IPT where an air agency chooses to 
include emissions reductions attributable to the NNSR air permitting in 
its initial 15 percent 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). This interpretation 
results from the fact that the CAA requires that a state's initial ROP 
plan can be satisfied only via reductions in VOC emissions. Hence, the 
EPA proposed that such a plan could not count emission reductions 
attributable to a NNSR permitting program utilizing IPT flexibilities, 
for ROP purposes.\42\
---------------------------------------------------------------------------

    \42\ See section III.E of this preamble.
---------------------------------------------------------------------------

    Finally, the EPA in the November 17, 2016, proposal also explained 
that IPT could be implemented in several ways; the primary variable 
being the method in which the IPT ratio for ozone precursors is 
established by an air agency or permit applicant and applied in a 
particular ozone nonattainment area. That is, the EPA proposed that 
states be allowed to choose any of the options presented in the 
proposal. Accordingly, with the goal of providing flexibility to air 
agencies and sources, the EPA proposed and sought comment

[[Page 63017]]

on the following implementation options:
    a. Case-specific Permit Ozone IPT Ratios. Under a case-specific IPT 
ratio option, state plans would generally require each permit applicant 
who chooses to use ozone IPT as the means for satisfying the NNSR 
emissions offset requirement to calculate and submit to the reviewing 
authority the appropriate IPT ratio. In choosing this option, the state 
would be required to include for the EPA's approval a plan submission 
addressing NNSR program provisions that explicitly authorize case-
specific IPT ratios for the particular ozone nonattainment area(s). 
Also, such a plan submission must include the procedures by which 
permit applicants may use IPT, including a description of the model(s) 
that will be used, the calculation of the IPT ratio, and a 
demonstration that such IPT ratio provides an equivalent or greater air 
quality benefit for ozone concentrations in the ozone nonattainment 
area. The EPA also proposed that the state's IPT provision must provide 
that any IPT ratio that an applicant proposes for an individual permit 
must be approved by both the reviewing authority and the EPA.
    b. Area-specific Default Ozone IPT Ratio. Under the proposed area-
specific default IPT option, the EPA proposed that a state plan could 
include a default IPT ratio that may be used by permit applicants to 
obtain IPT offsets for all applicable NNSR permits issued in a 
particular ozone nonattainment area. Under this proposed option, the 
state's plan submission would be required to provide a description of 
the model(s) used, the calculated ratio and the technical demonstration 
substantiating the equivalent or greater ozone benefit in that 
nonattainment area. The EPA further proposed that a 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 that ratio is utilized 
by individual permit applicants.
    c. Combination of an Area-specific Default Ozone IPT Ratio and 
Case-specific IPT Ratios. As explained in the proposed rulemaking, the 
EPA believes that it is reasonable for air agencies to have the option 
of implementing as part of their NNSR programs either a case-specific 
IPT ratio or a default IPT ratio. The EPA also believes that air 
agencies with EPA-approved NNSR programs should have the option of 
implementing a combination of the two proposed options. Such a combined 
program would enable an air agency to develop a default IPT ratio, 
while at the same time allowing 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).
    d. Limitations for Implementing Ozone IPT under Appendix S. In the 
specific case where a state lacks an approved NNSR program and issues 
NNSR permits under the requirements contained in the EPA's Emission 
Offset Interpretative Ruling at 40 CFR part 51, Appendix S (Appendix 
S), the EPA proposed that states would be limited to the use of case-
specific IPT ratios.
    In addition to the four options proposed for implementing the IPT 
program for ozone, the EPA proposed to require air agencies to review 
any default IPT ratio(s) that is included in their EPA-approved IPT 
program at least every 3 years (from the air agency's prior plan 
submission containing any such area-specific default IPT ratio(s)) to 
ensure that the ratio continues to be valid for IPT offsets in the 
area. To meet this proposed requirement an air agency would need to 
submit new modeling to confirm that the ratio still defines an 
equivalent or greater air quality benefit relationship between VOC and 
NOX emissions regarding ozone formation in the particular 
ozone nonattainment area.
    At proposal, the EPA included a draft TGD in the docket. The 
purpose of this TGD was to provide air agencies with guidance on a 
technical approach to determine ozone impacts from precursor emissions 
for a specific nonattainment area or for case-by-case determinations.
2. Final Rule and Rationale
    In this final rule, the EPA is promulgating a discretionary IPT 
program for ozone with changes from the proposed rulemaking based on 
comments received. The final rule allows states to implement their IPT 
program using any of the proposed implementation options as follows: 
(1) Default IPT ratios, (2) case-specific IPT ratios or (3) a 
combination of the two options, whereby a proposed source may, at the 
approval of the reviewing authority, propose a case-specific ratio in 
lieu of an available default IPT ratio. The following changes are being 
made in response to comments received: (1) Air agencies will not be 
required to obtain EPA approval of IPT ratios when implementing a case-
specific IPT program or when applying default IPT ratios that are not 
included in the state regulations and the SIP; and (2) the required 
periodic review of any default IPT ratio must be conducted every 5 
years, rather than every 3 years as proposed.
    The EPA acknowledges, based on comments received, that the 
requirement of EPA approval of IPT ratios could impose additional 
burdens and result in permit delays. Hence, in the final rule, the EPA 
is eliminating this approval requirement for the case-specific ratios 
and for default ratios that are not included in state regulations and 
the SIP. In the spirit of cooperative federalism, the EPA encourages 
air agencies to both work with the EPA in the development of IPT ratios 
and notify the EPA after the development of any initial or revised 
area-specific default IPT ratio for a particular ozone nonattainment 
area. Finally, the EPA will, of course, also have an opportunity to 
review and comment on the application of any IPT ratio (default or 
case-specific) to a particular source or location during the public 
comment period afforded as part of the NNSR permitting process.
    An air agency may choose to include a numerical default ratio in 
its NNSR regulations and the SIP to make that ratio controlling. 
Alternatively, if an air agency chooses not to include any numerical 
default IPT ratios in its regulations and SIP, EPA approval of the 
numerical default ratio is no longer required. However, for any such 
air agency, the final rule still requires the SIP to include (1) the 
authority to implement IPT; (2) a description of the air quality 
model(s) that may be used to develop any default IPT ratio; and (3) a 
description of the approach that the air agency will use to develop any 
default IPT ratio, which must show that such ratios provide an 
equivalent or greater ozone air quality benefit in the applicable ozone 
nonattainment area. The final rule also requires air agencies with IPT 
programs that authorize case-specific IPT ratios to require permit 
applicants to include along with the submittal of the proposed case-
specific ratio similar information pertaining to the development of the 
ratio.
    A default IPT ratio that is not in a state regulation and an 
approved SIP would be subject to public comment for each use in 
individual permits. Therefore, states may want to include numerical 
default IPT ratios in their regulations and submit them to the EPA for 
approval as part of the SIP. In such an instance, the regulation 
containing the area-specific default IPT ratio would be reviewed by the 
EPA as part of the SIP submission and, if approved, would provide 
states and other stakeholders with greater certainty that the IPT ratio 
will be applicable to all permit

[[Page 63018]]

applications. The validity of a default IPT ratio that has become part 
of an approved plan and has undergone public comment during the plan 
approval process would not be subject to additional public comment with 
regard to its numerical value each time that ratio is utilized by 
individual permit applicants.
    On the other hand, default ratios that are not included in a state 
regulation and SIP, and, therefore, are not subject to the EPA's 
approval, may be replaced more rapidly in situations where the ratio is 
no longer valid, e.g., as a result of a periodic review. An air agency 
can replace such a ratio with a revised value that will not have to be 
processed through rulemaking and a plan revision. Also, if an air 
agency determines through a periodic review that an existing default 
ratio is no longer valid and must be revised, the air agency may decide 
not to revise it but to rely solely on case-specific permit ratios to 
continue implementing IPT provided that the SIP contains the necessary 
authority to implement case-specific ratios as part of the NNSR program 
for ozone. Unlike the default IPT ratios, case-specific IPT ratios will 
not require periodic review because the ratio used for each individual 
permit will be based on the most current data representing the ozone 
chemistry for the area of concern.
    This final rule does not discourage or preclude an air agency 
desiring EPA approval from electing to either submit numerical default 
IPT ratio(s) to EPA for review and approval into its SIP, seek EPA 
approval of any case-specific IPT ratio or to simply seek consultation 
with the EPA on the development of any IPT ratio for ozone.
    For any state that lacks an approved NNSR program for ozone, the 
state may issue an NNSR permit pursuant to the NNSR requirements for 
ozone contained in 40 CFR part 51 Appendix S, which includes an IPT 
program. The final rule provides that the IPT program under Appendix S 
may be implemented only by using case-specific IPT ratios. In addition, 
the final rule includes a provision in Appendix S that requires permit 
applicants to include along with the submittal of the proposed case-
specific ratio information pertaining to the development of that ratio. 
Moreover, each case-specific permit IPT ratio would not require EPA 
approval but only the approval of the air agency.
    The EPA is including a revised final TGD in the docket for this 
rulemaking. The purpose of this TGD is to provide air agencies and 
source owners or operators, where applicable, with guidance on a 
technical approach to determine ozone impacts from precursor emissions 
for a specific nonattainment area or for case-specific determinations. 
The TGD provides a framework and associated general methodology to 
apply existing or new empirical relationships between ground level 
ozone concentrations and the two precursors--NOX emissions 
and VOC emissions--to develop the required IPT ratios.\43\ Air agencies 
may use existing modeling analyses or generate their own modeling 
analyses to provide the basis for the development of IPT ratios.\44\
---------------------------------------------------------------------------

    \43\ Please refer to the TGD included in this final rule docket 
and the section of the Response to Comments document related to the 
proposed TGD for further information.
    \44\ The EPA has not added any regulatory provisions in the NNSR 
regulations to require permitting authorities to use the data or 
methods described in the TGD.
---------------------------------------------------------------------------

    In addition, recent changes to the EPA's Guideline for Air Quality 
Models, published as Appendix W to 40 CFR part 51, provides greater 
clarity regarding the use of chemical transport modeling to estimate 
single-source ozone impacts from precursors. Appendix W provides 
guidelines for area-specific assessments of precursor emissions impacts 
on ozone and these guidelines may also support the development of case-
specific IPT ratios or area-specific IPT ratios for ozone precursors.
    Finally, the final rule attempts to strike a balance between 
providing flexibility for the offset requirement in NNSR permitting and 
compliance with the CAA's air quality protections. While EPA approval 
of ratios is no longer required, the EPA believes that the SIP 
requirements for air agencies to comply with the criteria for 
development of default IPT ratios and to conduct periodic reviews of 
each default ratio, along with the opportunity for the EPA to review 
the application of a ratio for a specific permit during the public 
comment period, afford adequate safeguards. In particular, the 
mandatory periodic review conducted by the air agency will ensure that 
each area-specific ratio either continues to adequately reflect the 
correct relationship between VOC and NOX emissions with 
respect to the formation of ground level ozone in a particular ozone 
nonattainment area or will result in such ratio being eliminated (and 
revised if so desired).
3. Comments and Responses
    Comment: Six commenters expressed concerns about the administrative 
burden associated with the proposed requirement for the EPA to approve 
all IPT ratios for ozone. These commenters believed that the EPA's 
approval of the SIP containing the authority to use IPT and the 
methodology for developing an IPT ratio would be sufficient. The 
commenters claimed that the EPA's approval of SIPs containing rules 
authorizing IPT is sufficient for compliance with the CAA requirements 
for EPA approval of SIPs, while the specific ratios applied to IPT 
should be a matter of NNSR permitting. The commenters stated that the 
CAA assigns the EPA a substantive role in approving SIPs but generally 
reserves NNSR permitting decisions to states. They thereby concluded 
that the determination of specific IPT ratios should be considered the 
province of the air agency and should not require EPA approval. One 
commenter, while generally opposing the proposed IPT provisions, argued 
that EPA approval of ratios would provide minimal, if any, benefit and 
that the EPA lacked the resources sufficient for such a process to be 
successful.
    Response: The EPA has considered the commenters' concerns about the 
proposed requirement for EPA approval of all IPT ratios for ozone. As a 
result, we have concluded that it would be appropriate to eliminate the 
proposed EPA approval requirement as part of the final rule while 
retaining the following safeguards: The final rule requires the SIP to 
include (1) the authority to implement IPT; (2) a description of the 
air quality model(s) that may be used to develop any default ratio; and 
(3) a description of the approach that the air agency will use to 
develop any default IPT ratio, which will show that such ratio(s) 
provide an equivalent or greater ozone air quality benefit in the 
applicable ozone nonattainment area. Accordingly, the final rule does 
not require EPA approval of any IPT ratio. The EPA agrees that the 
process of EPA approval could lengthen the time required for SIP 
approval (in the case of default IPT ratios) and for individual permit 
processing (in the case of case-specific IPT ratios).
    However, the EPA also believes that SIP approved default IPT ratios 
have great potential in burden reduction for both proposed projects as 
well as the state through an initial up-front effort in providing the 
technical demonstration supporting the desired default ratio with an 
equivalent or greater air quality benefit for such ratio's use in NNSR 
permitting. A SIP approved default IPT ratio could be used to provide a 
greater degree of certainty for projects each time it is used in an 
NNSR permit, since it would be presumed to be appropriate for each 
individual NNSR permit in that nonattainment area. To avail this 
greater

[[Page 63019]]

certainty of default IPT ratios, an air agency could choose to obtain 
formal approval of any default ratio by including it in its SIP 
submission.
    The EPA recommends that air agencies consult with the EPA and refer 
to the TGD for assistance in developing the technical demonstration 
supporting IPT as providing an equivalent or greater air quality 
benefit in the nonattainment area, whether implementing a case-specific 
or area-specific default ratio. The EPA also offers direct assistance 
to air agencies in the development of default IPT ratios upon request.
    Comment: Seven commenters advocated that the EPA take greater 
responsibility for the development of default IPT ratios. Five of the 
seven specifically recommended that the EPA provide the area-specific 
IPT ratios for ozone nonattainment areas to the air agencies. Two of 
the commenters, supporting a greater EPA responsibility, called upon 
the EPA to provide assistance to the states in developing default IPT 
ratios. All seven commenters generally agreed that the process to 
develop default IPT ratios is too burdensome for the states to conduct 
on their own. A state air agency commenter recommended that the EPA 
provide a mechanism to establish an alternative ratio ``that does not 
rely upon overly burdensome modeling exercises.'' The same commenter 
suggested that the EPA could instead rely upon a ratio of 
NOX and VOC inventories rather than photochemical modeling.
    Response: While the EPA continues to support the concept of a 
default ratio for a particular ozone nonattainment area, primarily for 
resource reasons it is not feasible at this time for the EPA to assume 
the responsibility for establishing ratios for all ozone nonattainment 
areas across the country. Additionally, it is not clear whether all 
states will adopt the discretionary IPT provisions or whether they will 
prefer default or case-specific IPT ratios. Taking into account these 
considerations, and the considerable resources required to conduct 
research and data analyses to establish IPT ratios for every 
nonattainment area, the EPA believes that it is more appropriate for 
states to assume the responsibility for developing IPT ratios for 
nonattainment areas if they decide to implement the voluntary IPT 
program.
    Concerning the commenters' recommendation for a mechanism for an 
alternative ratio that can be derived without reliance on a modeling 
demonstration, the EPA is not aware of an alternate methodology to show 
equivalent or greater ozone air quality benefit in a nonattainment 
area, which is an essential component of an acceptable ozone IPT ratio, 
nor has the commenter provided such methodology for consideration. 
Moreover, a ratio that relied upon NOX and VOC emissions 
inventories, as recommended by one commenter, would not be based on an 
air quality relationship between the two ozone precursors and would 
lack elements of the required technical demonstration to substantiate 
the required equivalent or greater air quality benefit for the ozone 
nonattainment area than a reduction (offset) of the emitted precursor 
would achieve.
    Comment: One commenter recommended the EPA not allow case-specific 
IPT ratios because such ratios could not be set in advance of the 
permitting process, although permit applicants need to know the 
appropriate amount of the precursor offsets that would be required in 
order to decide whether to apply for an NNSR permit.
    Response: Any major NNSR permit applicant would be required to do 
preliminary analysis to determine the Lowest Achievable Emissions Rate 
(LAER) and the amount of emissions offsets required. The EPA recognizes 
the importance of an applicant of knowing, in advance of applying for a 
permit to construct, the amount of emissions reductions that will be 
needed to satisfy the NNSR offset requirement. If a state has chosen to 
provide a default ratio, then that information is readily available to 
the applicant when contemplating a proposed construction project. If, 
however, a state also allows case-specific IPT ratios and the applicant 
believes that a lower, less conservative ratio may be more appropriate 
for the proposed project at a particular location within a 
nonattainment area, then the applicant may elect to propose in advance 
of the submittal of a permit application a case-specific IPT ratio that 
would apply only to that source project. Thus, the case-specific IPT 
ratio remains a valid option for permit applicants that find it useful.
    Comment: Some commenters expressed concern that the final rule 
would only allow one approach for developing the required IPT ratio. 
One commenter was concerned that states with more than one ozone 
nonattainment area would be required to select one approach to apply to 
all nonattainment areas within the state.
    Response: These commenters appear to have misunderstood the EPA's 
proposal concerning the different options described for states to 
consider in developing or revising IPT ratios for NNSR permitting. The 
EPA did not intend to limit the flexibility afforded to states with 
respect to how they can implement ozone IPT provisions (which includes 
the approach indicated by these commenters). As previously explained, 
the EPA proposed three options for states that choose for implementing 
an IPT program for ozone: (1) Procedures to develop an area-wide IPT 
ratio; (2) procedures to allow case-specific ozone IPT ratios 
applicable to single permits; or (3) a combination of the first two 
options with an area-specific default ratio that can be replaced by a 
case-specific ratio as proposed by the applicant. The EPA's intent is 
to maximize flexibility so that air agencies can choose a different 
option for each nonattainment area, rather than choose one option to 
apply at the statewide level, which means that two nonattainment areas 
in the same state could apply different options for ozone IPT ratios. 
The IPT program for ozone is not a mandatory program for air agencies 
to adopt. However, air agencies that choose to use any form of IPT 
program for ozone using the options provided in the final rule will 
need to revise their SIPs to ensure that their NNSR rules satisfy the 
minimum requirements contained in the final rule.
    Comment: Twelve commenters opposed the proposed requirement for a 
3-year periodic review of any area-wide IPT ratios. Several of these 
commenters opposed any review at all unless there is a specific basis 
(e.g., a new or revised attainment demonstration) to justify the need 
for review. Most of the remaining commenters recommended that a longer 
review period (generally 5-10 years) would be more appropriate than the 
proposed 3-year frequency. The commenters generally indicated that the 
proposed 3-year review would be overly burdensome and likely not 
reflect appreciable inventory changes. The commenters further noted 
that updating an ozone IPT ratio every 3 years after initial SIP 
approval requires months of modeling along with many weeks to follow 
public notice requirements and other applicable state requirements.
    Response: The EPA considered the comments concerning the proposed 
periodic review and the 3-year review cycle and has concluded that it 
is appropriate to make certain changes to the proposed approach. 
Specifically, the requirement for a periodic review of any default 
ratio is being retained; however, such reviews will be required every 5 
years rather than the proposed 3 years. The EPA notes that the 
requirement for periodic review does not apply to case-specific IPT 
ratios established for individual permits since each such ratio will be 
based on the relevant technical

[[Page 63020]]

information applicable to that particular permitting situation. The EPA 
disagrees with those commenters recommending that IPT review only occur 
at the states' discretion. The EPA is establishing a periodic review 
requirement for area-wide IPT ratios based on a 5-year review cycle to 
address the potential for changes in atmospheric conditions in an area, 
and to ensure that the requirement for equivalent or greater ozone 
benefits continues to be satisfied.
    The increase in the length of the review was supported by 
commenters in response to the proposal. Commenters supporting a review 
period specifically noted that the 3-year period was too short. Many of 
the commenters noted the procedural challenges in their own rulemaking 
process and that other contributing elements to the nonattainment area 
air shed do not change significantly enough to justify the effort of 
the review.\45\ They concluded that a 3-year review cycle would be too 
burdensome to adopt as a provision. Further, recent research suggests 
ozone formation in an area changes over time but is typically fairly 
consistent in a given 3 to 5-year period.\46\ Therefore, the EPA has 
decided to increase the proposed 3-year review period to a 5-year 
review period in order to provide air agencies a more reasonable period 
of time to satisfy the requirement and to afford sufficient time to 
reflect inventory changes. It is important to note that the final rule 
would also not require EPA approval of periodically reviewed ratios 
that are not included in regulations and the SIP. This will enable an 
air agency to effectuate an updated default ratio more quickly, but 
such a default ratio will be subject to public comment as part of the 
NNSR permitting process. However, similar to the development of the 
initial default ratio, the EPA encourages air agencies to both work 
with the EPA in the development of a revised default IPT ratio for a 
particular ozone nonattainment area and notify the EPA after such a 
ratio has been developed.
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    \45\ See Section VIII.B of the Response to Comments document for 
further information.
    \46\ Evaluating a Space-Based Indicator of Surface Ozone-
NOx-VOC Sensitivity Over Midlatitude Source Regions and 
Application to Decadal Trends, Xiaomeng Jin, Arlene M. Fiore, Lee T. 
Murray, Lukas C. Valin, Lok N. Lamsal, Bryan Duncan, K. Folkert 
Boersma, Isabelle De Smedt, Gonzalo Gonzalez Abad, Kelly Chance, and 
Gail S. Tonnesen, Journal of Geophysical Research: Atmospheres, 
October 5, 2017.
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    Comment: Five commenters advocated that the EPA provide a 
reasonable transition period for any pre-existing IPT programs that a 
state may be currently implementing. Some of these commenters 
explicitly recommended that states be allowed to continue the 
implementation of pre-existing ozone IPT programs without including 
revised IPT provisions as part of any other required revisions to the 
ozone NNSR regulations.
    Response: Existing provisions in an EPA-approved SIP remain in 
effect until any revisions to those provisions are approved by the EPA 
as a revision to the SIP. Accordingly, states that already implement a 
SIP-approved ozone IPT program can continue to implement that approved 
program until the program is revised. States are required to submit a 
SIP revision regarding the state's NNSR program. Even if a state 
believes that its pre-existing IPT program is sufficient to meet the 
requirements established in this rulemaking, the state's SIP submittal 
must demonstrate this to be so by including information to support the 
implementation of IPT subject to the requirements of this rule. In the 
case of any default ratios that are already in a SIP, this includes a 
technical demonstration supporting an equivalent or greater ozone air 
quality benefit for the existing default IPT ratio, and a 5-year 
periodic review.
    Comment: Two commenters objected to the proposed ozone IPT 
provisions on the grounds that allowing IPT is unlawful. One of the 
commenters claims the IPT provision would put human health at risk 
because it contributes to delays in attaining the standards. The other 
commenter provides a detailed argument claiming that the proposed ozone 
IPT provision violates the express terms of the CAA. This commenter 
interprets the offset requirement under CAA Section 173(c)(1), which 
specifically refers to an ``air pollutant,'' to apply only to the 
particular precursor emitted (VOC or NOx), rather than to 
the ambient air pollutant (ozone) for which the region is in 
nonattainment, noting that the Act establishes VOC-specific offset 
ratios required for ozone permitting.
    Response: The EPA disagrees with the commenters' narrow 
interpretation of ``air pollutant'' under CAA Section 173(c)(1).\47\ 
CAA section 302(g), which defines ``air pollutant,'' provides that the 
term includes ``. . . 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).\48\ Further, CAA section 
109(a) directs the Administrator to promulgate NAAQS for ``each air 
pollutant for which air quality criteria have been issued. . . .'' The 
criteria pollutant in this context is ozone--not its precursors. 
Further, in accordance with CAA section 107(d)(4), the air pollutant 
for which the area is designated nonattainment is ozone, and there is 
no mention of NOX or VOC.
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    \47\ 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.'' (Emphases added.)
    \48\ See 57 FR 55620, November 25, 1992, at page 55621 and 55624 
(PSD and NNSR Applicability), and 1991 Memo ``New Source Review 
Program Transitional Guidance'' at page 5.
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    While an area's attainment designation is made for the criteria air 
pollutant ozone, the control of ground level concentrations of ozone 
has occurred largely through regulation of its precursor emissions, 
which are NOX and VOC. Both the CAA and the EPA's NNSR 
regulations identify emissions of 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 emissions and VOC emissions. 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 tpy) pursuant to an IPT ratio that 
demonstrates that the reductions will have an equivalent or greater air 
quality benefit with respect to ground level concentrations of the 
ambient air pollutant ozone. Further, section 173(a)(1)(A) of the CAA 
requires an NNSR permitting offset to be consistent with RFP (as 
defined in CAA section 171(1)). Specifically, this provision requires 
that the offsetting emissions reductions are such that the total 
allowable emissions in the area, including the proposed source or 
modification when the source commences operation, will be sufficiently 
less than the emissions from the total emissions of existing sources 
before the permit application, to represent RFP when considered 
together with the provisions of the nonattainment SIP. Section 171(1) 
of the CAA defines RFP as ``annual incremental reductions in emissions 
of the relevant air pollutant . . . for the purposes of the applicable 
NAAQS by the applicable date.'' This requirement serves as insurance 
that IPT offsets must not interfere with NAAQS attainment for ozone.

[[Page 63021]]

    Additionally, the commenters note that the Act establishes VOC-
specific offset ratios required for ozone permitting. The IPT 
provisions at issue in this rulemaking are for the NNSR permitting 
offset requirement for ozone and stem from the CAA section 173(c) 
requirement to offset ``increased emissions of any air pollutant'' 
rather than a requirement that specifically identifies the precursor at 
issue.\49\ Of note, the EPA is not suggesting that a VOC-specific SIP 
requirement where Congress has not permitted NOX 
substitution can be satisfied by utilizing either precursor 
interchangeably. Specifically, in CAA section 182(b)(1), for newly 
listed Moderate and higher classified nonattainment areas, there is a 
requirement that a reduction in VOC emissions of 15 percent be 
achieved. In the case of a nonattainment area (Moderate and higher 
classified) that has not previously achieved the 15 percent VOC ROP 
reduction and is seeking to utilize NNSR permitting as one of the 
methods by which it will achieve the required VOC reductions, the state 
is not allowed to utilize IPT in its NNSR program.
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    \49\ If anything, the statement in section 182(c)(2)(C) 
permitting NOX substitution that ``would result in a 
reduction in ozone concentrations at least equivalent to that which 
would result from the amount of VOC emission reductions required 
under subparagraph (B)'' evidences Congress's understanding that 
NOX reductions, when properly calculated, can be utilized 
to result in equivalent ozone reductions as VOC emissions; a 
contention which the commenters dispute and is discussed below in 
addressing the commenters' ``anti-backsliding'' comments.
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    Comment: One commenter argued that the IPT provision for ozone 
violates the CAA's anti-backsliding requirements because ``[a] rule 
that allows a new major source to be constructed and emit increased 
levels of a pollutant that would have been barred under prior rules is 
by definition less stringent.'' Additionally, the commenter asserted 
that the IPT provision would put human health at risk and fails to 
assure equivalent or greater ozone reduction benefit.
    Response: The commenter did not identify any specific CAA 
requirements in their comments with regard to anti-backsliding. Based 
on the commenter's statement that the proposed rulemaking ``unlawfully 
and arbitrarily authorize[s] controls for that pollutant that are less 
stringent than required under the pre[hyphen]existing NAAQS,'' the 
commenter appears to be referencing the EPA's application of section 
172(e); however, this provision applies to relaxation of a prior NAAQS. 
The EPA is not relaxing a prior NAAQS in this action, and thus section 
172(e) does not apply.
    As the EPA has stated, the IPT approach outlined in the proposal 
and being finalized here represents the longstanding policy of the 
EPA.\50\ Therefore, it is not ``less stringent'' than the agency's 
prior approach. Moreover, the commenter provided no analysis or support 
for the assertion that this rule would allow ``a new major source to be 
constructed and emit increased levels of a pollutant that would have 
been barred under prior rules.''
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    \50\ See Louisiana; Final Rule: 67 FR 61260, September 30, 2002 
(proposed at 67 FR 48090, July 23, 2002); Texas; Final Rule: 71 FR 
52664, September 6, 2006 (proposed at: July 23, 2001); Mass 
Emissions Cap and Trade Program proposal (66 FR 38240; July 23, 
2001).
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    The EPA also disagrees with commenter's claims that the proposed 
rulemaking would put human health at risk and that IPT fails to assure 
equivalent or greater ozone reduction benefits. In both the proposed 
and final rule, the use of any IPT ratio is predicated on a 
demonstration that assures exactly that. See, e.g., 40 CFR 
51.165(a)(11)(i)(B)(I) and (C). The commenter claimed that the 
``proposal nowhere finds or demonstrates that any specific trading 
ratios will be sufficient to assure equivalent or greater ozone 
reductions in any particular ozone nonattainment areas, nor does it 
specify with precision the methods and supporting data required to make 
such a demonstration.'' These critiques are premature and would only be 
germane if the commenter sought to dispute the approval of a specific 
IPT ratio. As discussed earlier in response to comments requesting that 
the EPA directly develop ratios for each nonattainment area as part of 
this final rule, the EPA maintains that we cannot, and will not 
endeavor to, identify all possible specific trading ratios for all 
areas. Rather, the EPA has defined three different procedural 
approaches for implementing IPT and provided technical guidance to 
assist air agencies (and permit applicants, where applicable) in the 
establishment of such ratios.
    Furthermore, the ability of an IPT ratio to assure equivalent or 
greater ozone reductions has been acknowledged by Congress. CAA section 
182(c)(2)(C) permits air agencies to demonstrate that substituting 
NOX emissions for VOC emissions to satisfy the VOC-specific 
requirements of CAA section 182(c)(2)(B) ``would result in a reduction 
in ozone concentrations at least equivalent to that which would result 
from the amount of VOCs emission reductions required.'' In that 
context, Congress specifically authorized the substitution because it 
related to a VOC-specific requirement. The IPT provisions in this final 
rule, relate to the ambient air pollutant ozone, and, thus, as 
discussed previously, specific authorization to substitute precursors 
is not necessary as part of the section 173(c) offset requirement 
because, as discussed earlier, CAA section 302(g) defines ``air 
pollutant'' to include ``any precursors to the formation of any air 
pollutant.'' However, section 182(c)(2)(C) is noteworthy because it 
formalizes Congress' acknowledgement that, contrary to the commenter's 
assertions, IPT can be implemented in a manner which assures equivalent 
or greater ozone reductions.

E. Emissions Inventory and Emissions Statement Requirements

    The EPA proposed to clarify our emissions inventory and emissions 
statement requirements for purposes of the 2015 ozone NAAQS 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). For 
purposes of the 2015 ozone NAAQS, we proposed to add 40 CFR 51.1315, to 
clarify requirements for the emissions inventories required by CAA 
sections 182(a)(1) and 182(a)(3)(A). We also provided a preamble 
discussion in the proposed rulemaking to clarify the emissions 
statement requirements of 182(a)(3)(B), and are finalizing 40 CFR 
51.1315 consistent with that discussion in this final rule.
1. Emissions Inventories
    a. Summary of Proposal. The EPA proposed to retain our existing 
approach to the general emissions inventory requirements for purposes 
of the 2015 ozone NAAQS, as articulated in the final 2008 Ozone NAAQS 
SIP Requirements Rule.\51\ We also proposed revisions to point source 
reporting thresholds in the AERR (codified in 40 CFR 51, subpart A) to 
be consistent with the major source thresholds for ozone nonattainment 
areas.
---------------------------------------------------------------------------

    \51\ The preamble to the final 2008 Ozone NAAQS SIP Requirements 
Rule provides an extensive discussion of the EPA's rationale and 
approach for emissions inventories (80 FR 12289; March 6, 2015).
---------------------------------------------------------------------------

    The emissions inventory requirements for the 2008 ozone NAAQS, 
found at 40 CFR 51.1115, describe the criteria and timing for base year 
and periodic

[[Page 63022]]

inventories required under CAA sections 182(a)(1) and 182(a)(3)(A), 
respectively. To support the periodic emissions inventory requirement, 
the EPA proposed 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 Serious, Severe and Extreme areas of 
50, 25 and 10 tpy. With the 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 emission thresholds also depend on whether the source is 
within an OTR in accordance with CAA 184(b)(2). The EPA proposed 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, proposing to apply the same definition noted 
earlier in 40 CFR 70.2 and 40 CFR 71.2. Finally, the proposal removed 
the 100 tpy PTE CO threshold from the AERR tables in Appendix A for 
ozone nonattainment areas because there is no corresponding major 
source threshold for CO in the existing or proposed implementing 
regulations for the ozone NAAQS.
    b. Final Rule. The EPA is finalizing the proposed emissions 
inventory requirements, with the exception of the proposed AERR Table 1 
reporting threshold for NOX sources within an OTR, as 
explained more fully later. In general, we are providing that air 
agencies may rely, when appropriate, on their 3-year cycle inventory as 
described by the AERR 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.\52\ 
For all of the mobile source inventories used for 2015 ozone NAAQS 
implementation, states should use the latest emissions models available 
at the time that the attainment plan inventory is developed.\53\ In 
general, for states other than California that choose to fulfill 
various modeling requirements by using the latest EPA emissions model, 
the latest approved version of the MOtor Vehicle Emissions Simulator 
(MOVES) model should be used to estimate emissions from onroad and 
certain nonroad transportation sources. States should use the latest 
available planning emission inputs including, but not limited to, 
vehicle miles traveled, speeds, fleet mix, SIP control measures and 
fuels. The current version of MOVES is available at: https://www.epa.gov/moves. 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 (EMission FACtors) model. EMFAC2014 is the most 
recently approved model.\54\
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    \52\ States should consult the guidance document titled 
``Emissions Inventory Guidance for Implementation of Ozone and 
Particulate Matter National Ambient Air Quality Standards (NAAQS) 
and Regional Haze Regulations,'' EPA-454/B-17-003, July 2017, and 
any subsequent updates to that guidance that the EPA may make 
available at: https://www.epa.gov/air-emissions-inventories/emissions-inventory-guidance-implementation-ozone-and-particulate-matter.
    \53\ Section 172(c)(3) of the CAA requires that emissions 
inventories be based on the most comprehensive, accurate and current 
information available. To do so, air agencies should use the most 
up-to-date method for estimating emissions.
    \54\ The EPA is aware that EMFAC2017 has been made available by 
the California Air Resources Board and is currently reviewing that 
model. However, EMFAC2017 should not be used for any conformity 
analyses until the EPA officially approves the model for that 
purpose.
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    The EPA is finalizing the proposed updates to AERR Table 1 that 
explicitly include the same Serious, Severe and Extreme area thresholds 
for NOX as currently exist for VOC. We are also removing the 
100 tpy PTE CO threshold from Appendix A for ozone nonattainment areas, 
as proposed.
    We are not finalizing our proposal to revise the NOX 
reporting threshold for sources within an OTR from 100 tpy to 50 tpy. 
This revision would have aligned the NOX reporting threshold 
with that for VOC sources in an OTR, which is established as 50 tpy in 
CAA section 184(b)(2) and in subsection 3(ii) of the definition of 
``major source'' in 40 CFR 70.2 and 40 CFR 71.2. For nonattainment 
areas, CAA section 182(f)(1) applies the planning requirements for 
major stationary sources of VOC to NOX sources within 
nonattainment areas classified Serious and higher. Major stationary 
sources of NOX for nonattainment areas are thus defined by 
the same corresponding emissions thresholds for VOC sources under CAA 
sections 182(c) (Serious areas, 50 tpy), 182(d) (Severe areas, 25 tpy) 
and 182(e) (Extreme areas, 10 tpy). Section 184 of the CAA does not 
include NOX requirements for major stationary sources of VOC 
in an OTR, while CAA section 184(b)(2) specifically provides that major 
stationary sources of VOC (i.e., at least 50 tpy VOC) would be subject 
to requirements applicable to major stationary sources in a Moderate 
nonattainment area. The EPA's proposed revision of the OTR 
NOX reporting threshold was intended to establish a 
parallel, consistent basis for emissions reporting requirements for VOC 
and NOX sources in an OTR. However, after considering 
comments received (see later), the EPA has determined that our proposal 
incorrectly interpreted the interaction between CAA sections 182 and 
184 as requiring a NOX reporting threshold of 50 tpy in the 
OTR. CAA section 182(f) states that the planning requirements for ozone 
nonattainment areas that apply to major stationary sources of VOCs will 
also apply to major stationary sources of NOX, but it does 
not say the major stationary source definition for VOCs (such as the 50 
tpy threshold contained in 184(b)(2) for stationary sources in the OTR) 
shall also apply to determining major stationary sources of 
NOX. Instead, section 182(f) specifically defines major 
stationary sources of NOX with reference to the general 
definition contained in CAA section 302, which applies a 100 tpy 
emission threshold (see 42 U.S.C. 7602(j)), and the thresholds for 
Serious, Severe and Extreme nonattainment areas contained in CAA 
section 182(c), (d) and (e) (i.e., 50, 25 and 10 tpy, respectively). 
Interpreting CAA section 182(f) as establishing a 100 tpy threshold for 
major stationary sources of NOX in the OTR is consistent 
with the EPA's longstanding position regarding the interaction between 
section 182 and 184.\55\ We are therefore not finalizing our proposal 
to revise the NOX reporting threshold for sources within an 
OTR, and are retaining the existing general NOX reporting 
threshold of 100 tpy. Major stationary sources within an OTR that are 
also located in ozone nonattainment areas classified Serious and higher 
would be subject to the

[[Page 63023]]

corresponding major source thresholds for those area classifications.
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    \55\ See 57 FR 55620, 55622 (November 25, 1992) (stating that 
section 184(b)(2) ``is specifically limited to VOC sources because 
section 182(f) does not refer to the section 184 definition in 
describing the major stationary source definitions applicable for 
NOX purposes''); Region 1 EPA New England NOX 
RACT Summary (stating that for ``Marginal and Moderate nonattainment 
areas and attainment areas in the OTR, a major NOX source 
is one with the potential to emit 100 tpy or more of 
NOX''), https://www3.epa.gov/region1/airquality/noxract.html.
---------------------------------------------------------------------------

    c. Comments and Responses. Comment: Two commenters did not support 
the EPA's proposed revision of the NOX reporting threshold 
for sources within an OTR from 100 tpy to 50 tpy. The commenters 
contended that any changes to reporting thresholds in AERR Table 1 must 
be consistent with major source definitions established in the CAA and 
regulation.
    Response: We agree with the commenters and are not finalizing the 
proposed revision. As discussed previously, we have determined that CAA 
section 182(f) does not apply the major stationary source threshold for 
VOCs contained in 184(b)(2) to major stationary sources of 
NOX in an OTR.
2. Emissions Statements
    For nonattainment areas, air agencies must develop, and include in 
their SIPs, emission reporting programs for certain VOC and 
NOX sources in accordance with CAA section 182(a)(3)(B).\56\ 
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 under 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 agency. 
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.\57\ To properly 
implement the emissions reporting requirements, emissions statement 
regulations should be coordinated carefully with the data elements that 
are required by the EPA (the existing requirements at 40 CFR 51.1115 
and the requirements finalized in this rule 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, 51.103 and Appendix V, establishes the procedure for 
submitting a SIP revision.
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    \56\ CAA section 182(a)(3)(B)(2) allows that air agencies may 
waive, with the EPA's approval, the requirement for emission 
statements for classes or categories of sources with less than 25 
tpy of actual plant-wide NOX or VOC emissions in 
nonattainment areas, provided the class or category is included in 
the base year and periodic inventories required under CAA sections 
182(a)(1) and 182(a)(3)(a), respectively. Emissions in this case 
must be calculated using emission factors established by the EPA, or 
other methods acceptable to the EPA. We emphasize that the 25 tpy 
emissions threshold applies separately for purposes of emissions 
statement requirements, and does not relate to the major stationary 
source reporting thresholds for emissions inventories in AERR Table 
1.
    \57\ 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 SIP-related topics for 
which the EPA did not propose specific regulatory provisions due to 
lingering legal issues, scientific unknowns and uncertainties 
associated with developing and implementing new regulatory requirements 
and/or policies. The EPA is using this final rule notice, however, to 
articulate our existing requirements and policies pertaining to these 
topics and to inform possible future actions.

A. Managing Emissions From Wildfire and Wildland Prescribed Fire

    a. Proposed Recommendation. The preamble to the proposal for this 
rule recognized both that prescribed fires are a source of emissions 
that can have a greater or lesser impact on ozone concentrations 
depending on how and when the prescribed fire is conducted, and that a 
prescribed fire program can be a way to reduce emissions from 
catastrophic wildfires which can impact ozone concentrations. In the 
preamble to the proposal, the EPA proposed to recommend, as guidance to 
air agencies, that in their attainment demonstrations they account for 
emissions from wildfire and wildland prescribed fire as described in 
the final PM2.5 SIP Requirements Rule.
    b. Final Recommendation. The EPA continues to recommend that air 
agencies use the approach described in the final PM2.5 SIP 
Requirements Rule when accounting for emissions from wildfire and 
wildland prescribed fire. Before explaining this recommendation 
further, the EPA wishes to emphasize that this recommendation is 
focused on wildland fire management. There are other uses of prescribed 
fire and other types of burning that may occur in nonattainment areas, 
or that may 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.\58\ The challenges with applying the traditional 
nonattainment planning framework discussed here are particular to 
wildland fire and prescribed fire on wildlands. The EPA believes that 
addressing these other uses of prescribed fire does not present nearly 
the same level of challenge as does addressing wildland fire, 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 in ozone concentrations 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.
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    \58\ 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 we continue to encourage 
federal, state, local and tribal agencies and private land owners, to 
take situation-appropriate steps to minimize impacts from prescribed 
fire emissions on wildland. The EPA encourages all land owners and 
managers to apply appropriate basic smoke management practices (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 land owners 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 SIPs as enforceable measures 
and credited for emissions reductions (of ozone and precursors) that 
would help the area attain the standard.\59\ Instead, the EPA

[[Page 63024]]

recommends that ozone nonattainment plans (and in particular the 
attainment demonstrations) not account for expected air quality changes 
over the planning period resulting from changes in the use of wildland 
prescribed fire or other wildland fire management practices 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 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.
---------------------------------------------------------------------------

    \59\ These reasons include concerns raised by commenters on the 
PM2.5 SIP Requirements Rule 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 the fact that air quality data actually 
influenced by fire events may ultimately be excluded for regulatory 
purposes under the provisions of the Exceptional Events Rule (40 CFR 
50.14).
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    The EPA acknowledges that some level and 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 source categories where express accounting of emissions 
changes is being done. This final rule does not constrain the options 
for states regarding the appropriate assumptions to make for fire 
emissions. Rather, the guidance in this preamble simply recommends that 
once this base level is established, ozone plans should not attempt to 
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 wildland 
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 
wildland fire emissions generally should be held constant in the air 
quality modeling over the planning period, regardless of whether 
wildland fire management practices by land managers are expected, and 
possibly encouraged or required, to change.
    Air agencies have flexibility in determining how best to represent 
wildland fire emissions. As noted earlier, base year emissions 
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 ozone as an example, some plans under previous ozone 
NAAQS have estimated the actual fire emissions and temporal and spatial 
patterns from a given year and used this same estimate as part of the 
assumed future baseline inventory 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 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 the aforementioned difficulties 
associated with such quantification.
    To be clear, nothing about this recommendation regarding RACM is 
intended to suggest that prescribed 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 
guidance in this preamble simply makes clear the EPA's view regarding 
our recommendation for RACM for wildland fires.
c. Comments and Responses
    Comment: The EPA received comments expressing agreement with the 
EPA's recommended approach to managing emissions from wildfire and 
wildland prescribed fires. A few commenters took positions on 
specifically how to define RACM for wildfires, ranging from suggesting 
that the EPA require smoke management plans to simply stating that 
prescribed fires themselves are RACM with no further measures required. 
Some commenters disagreed with our position that states not take credit 
in the SIP for emission reductions attributable to a reduced incidence 
of wildfire if the state can demonstrate that the measures in the SIP 
can be expected to reduce emissions from wildfire events that would 
ordinarily not be excluded from the design value for the area. Other 
commenters disagreed with our recommendation that wildfire emissions be 
kept constant in projections for the attainment demonstration.
    Response: In light of the fact that the EPA did not propose 
specific guidance on defining RACM for wildfires and typically does not 
define RACM for specific categories, and the fact that the EPA is not 
recommending that states include RACM for wildland fires, we are not 
providing further guidance in response to those comments. The basis for 
recommending that wildfire emissions be kept constant in baseline 
projections is explained earlier and is driven by the uncertainties 
(e.g., patterns, timing and variability) in predicting fire emissions 
that affect ozone levels in in nonattainment areas. This recommendation 
is only guidance, and is not binding on the states or the EPA. In our 
actions on individual SIPs, the public will have the opportunity to 
make similar comments and we will consider those comments in the 
context of those actions.

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 applicable 
state, tribal or federal implementation plan (collectively referred to 
as the SIP in the remainder

[[Page 63025]]

of this section). Conformity to the applicable implementation plan 
means that federal activities will not cause or contribute to new 
violations of the standards, 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 
nonattainment areas redesignated to attainment that are required to 
have a CAA section 175A maintenance plan after 1990 (``maintenance 
areas''). Because certain provisions of section 176(c) apply only to 
highway and mass transit funding and approval actions, the EPA 
published two sets of regulations to implement section 176(c).
    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 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 so that existing transportation 
conformity requirements apply for any new or revised NAAQS (77 FR 
14979; March 14, 2012). The Transportation Conformity Rule, therefore, 
does not need to be updated to reflect the 2015 ozone NAAQS. The EPA in 
June 2018 issued an update to existing transportation conformity 
guidance related to the implementation of the revised ozone NAAQS. The 
guidance is available at: https://www.epa.gov/state-and-local-transportation/policy-and-technical-guidance-state-and-local-transportation. For further information on transportation conformity 
rulemakings, policy guidance and outreach materials, see the EPA's 
website at https://www.epa.gov/state-and-local-transportation.
    The EPA's general conformity regulations (40 CFR part 51, subpart W 
and 40 CFR part 93, subpart B) establish the criteria and procedures 
for determining whether activities not addressed by the transportation 
conformity rule conform to the appropriate implementation plan. The EPA 
first promulgated general conformity regulations in November 1993 (58 
FR 63214; November 30, 1993)). 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 
related to highway and transit funding and approval actions will not 
interfere with the appropriate implementation plan. 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 general conformity determinations and allows 
for air quality review of individual federal actions. More information 
on the general conformity program is available at https://www.epa.gov/general-conformity.
2. Why is the EPA discussing transportation and general conformity in 
this final rulemaking?
    The EPA is discussing transportation and general conformity in this 
rulemaking in order to provide affected parties with information on 
when conformity must be implemented after areas are designated 
nonattainment 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, local and tribal 
transportation and air quality agencies, metropolitan planning 
organizations and federal agencies including the U.S. Department of 
Transportation (DOT), the U.S. Department of Defense (DOD), the U.S. 
Department of Interior (DOI) and the U.S. Department of Agriculture 
(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 the 2015 ozone NAAQS. 
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 nonattainment areas. The 
grace period applies even if the area had been designated nonattainment 
for a prior ozone NAAQS. For additional information on transportation 
conformity requirements and the 1-year grace period please refer to the 
EPA's transportation conformity guidance for the 2015 ozone NAAQS 
available at: https://www.epa.gov/state-and-local-transportation/policy-and-technical-guidance-state-and-local-transportation.
    As discussed in Section II of this preamble, the EPA proposed and 
sought comment on two alternative approaches for revoking the 2008 
ozone NAAQS for all purposes and, where applicable, establishing anti-
backsliding requirements. We are not taking any final action regarding 
an approach for revoking a prior ozone NAAQS and establishing anti-
backsliding requirements; the EPA intends to address any revocation of 
the 2008 ozone NAAQS and any potential anti-backsliding requirements in 
a separate future rulemaking. We note here that the CAA requires 
transportation and general conformity determinations in areas that are 
designated nonattainment or maintenance for a given pollutant and 
standard, which at this time includes the 2008 ozone NAAQS.
4. 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 
general conformity determinations. 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 
prescribed fire in these areas should be assessed in concert with those 
federal land management agencies. In such areas the EPA encourages air 
agencies to consider including, in any baseline, modeling and SIP 
attainment inventory used and/or submitted, 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 fires 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.\60\
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    \60\ USDA Forest Service and Natural Resources Conservation 
Service, Basic Smoke Management Practices Tech Note, October 2011, 
available at: http://www.nrcs.usda.gov/internet/FSE_DOCUMENTS/stelprdb1046311.pdf.

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[[Page 63026]]

C. Requirements for Contingency Measures in the Event of Failure To 
Meet a Milestone or To Attain

1. Summary of Proposal
    For purposes of the 2015 ozone NAAQS, the EPA proposed no changes 
to the requirements for contingency measures articulated in the final 
2008 Ozone NAAQS SIP Requirements Rule (80 FR 12285; March 6, 2015). As 
required by the CAA, states must include in their nonattainment area 
SIPs contingency measures that are consistent with CAA section 
172(c)(9). For areas classified Serious or higher, states must also 
include contingency measures that are also consistent with CAA section 
182(c)(9), with a limited exception for Extreme nonattainment areas 
relying on plan provisions approved under CAA section 182(e)(5).
2. Final Rule
    The EPA is finalizing the proposed requirements. Contingency 
measures required under CAA sections 172(c)(9) and 182(c)(9) must be 
fully adopted rules or measures that can take effect without further 
action by the state or the EPA upon failure to meet milestones or 
attain by the attainment deadline. Per the EPA guidance,\61\ these 
measures should provide 1 year's worth of emissions reductions, or 
approximately 3 percent of the baseline emissions inventory. Once 
triggered, 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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    \61\ ``Guidance on Issues Related to 15 Percent Rate-of-Progress 
Plans,'' Memorandum from Michael H. Shapiro, Acting Assistant 
Administrator for Air and Radiation, to Regional Air Directors 
(August 23, 1993), 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 continuing to allow contingency 
measure emissions reductions 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.
    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 continuing 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 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).\62\ 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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    \62\ 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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    As noted in the November 17, 2016, proposed rulemaking, the EPA 
acknowledges that the U.S. Court of Appeals for the Ninth Circuit 
issued an opinion in Bahr v. EPA, 836 F.3d 1218 (9th Cir. 2016), cert. 
denied, 199 L. Ed. 2d 525, 2018 U.S. LEXIS 58 (Jan. 8, 2018), which 
rejected the EPA's longstanding interpretation of CAA section 172(c)(9) 
in the context of a SIP for particulate 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 does 
not currently plan to alter the agency's longstanding interpretation 
outside of the Ninth Circuit, especially in light of a prior decision 
from the U.S. Court of Appeals for the Fifth Circuit upholding that 
interpretation. See Louisiana Envt'l Action Network v. EPA, 382 F.3d 
575 (5th Cir. 2004) (LEAN); see also 40 CFR 56.5(b).
3. Comments and Responses
    Comment: A commenter noted that the EPA acknowledges the Bahr v. 
EPA decision, but declines to abide by it. The commenter asserts that 
Bahr was properly decided, and the EPA must follow it with regards to 
contingency measures required under CAA sections 172(c)(9), 182(c)(9) 
and 182(e)(5).
    Response: The appropriateness of relying on already-implemented 
reductions to meet the contingency measures requirement has been 
addressed in two federal circuit court decisions. See LEAN, 382 F.3d at 
586; Bahr, 836 F.3d 1218. The EPA believes that the language of 
sections 172(c)(9) and 182(c)(9) is ambiguous with respect to this 
issue, and that it is reasonable for the agency to interpret the 
statutory language to allow approval of already implemented measures as 
contingency measures, so long as they meet other parameters such as 
providing excess emissions reductions that the state has not relied 
upon to make RFP or for attainment in the nonattainment plan for the 
NAAQS at issue. Until the Bahr decision, under the EPA's longstanding 
interpretation of CAA section 172(c)(9) and 182(c)(9), states could 
rely on control measures that were already implemented (so called 
``early triggered'' contingency measures) as a valid means to meet the 
Act's contingency measures requirement. The Ninth Circuit decision in 
Bahr has created a split among the federal circuit courts, with the 
Fifth Circuit upholding the agency's interpretation of section 
172(c)(9) to allow early triggered contingency measures and the Ninth 
Circuit rejecting that interpretation.
    States located in circuits other than the Ninth may elect to rely 
on the EPA's longstanding interpretation of section 172(c)(9) allowing 
early triggered measures to be approved as contingency measures, in 
appropriate circumstances. The EPA's revised Regional Consistency 
regulations pertaining to SIP provisions authorize the agency to follow 
this interpretation of section 172(c)(9) in circuits other than the 
Ninth. See 40 CFR part 56. To ensure that early triggered contingency 
measures appropriately satisfy all other relevant CAA requirements, the 
EPA will carefully review each such measure contained in an air 
agency's submission, and intends to consult with air agencies 
considering such measures early in the attainment plan development 
process.

[[Page 63027]]

D. Background Ozone

    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.\63\ 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.\64\ Workshop 
attendees included representatives of state, local and tribal air 
agencies and other interested stakeholders. General concerns expressed 
by attendees that commented were that the EPA is underestimating the 
magnitude and effects of USB, that available policy solutions do not 
provide meaningful relief from nonattainment designations in affected 
areas, and that USB can make meeting nonattainment area requirements 
unreasonably difficult or costly.\65\
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    \63\ For purposes of NAAQS implementation, the EPA considers USB 
to be any ozone formed from sources or processes other than U.S. 
manmade emissions of NOX, VOCs, methane and CO.
    \64\ The white paper and other workshop details are available 
at: https://www.epa.gov/ozone-pollution/background-ozone-workshop-and-information.
    \65\ 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 available at http://www.regulations.gov (Docket ID No. EPA-HQ-OAR-2016-0097).
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    The EPA continues to engage with stakeholders and the academic 
community to refine and conduct 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 
and new understandings that may emerge from ongoing research and 
analysis. In 2017 and 2018, the EPA activities include participation in 
the Background Ozone Science Assessment organized by the Western States 
Air Resources Council, the Western Regional Air Partnership and the 
American Petroleum Institute,\66\ the United Nations' Hemispheric 
Transport of Air Pollutants task force \67\ and the U.S. National Air 
and Space Administration's Health and Air Quality Applied Sciences 
Team.\68\ Each of these efforts includes workshops for stakeholders and 
development of scientific products that inform the EPA's understanding 
of USB. However, the EPA is not adopting requirements regarding 
background ozone with this rulemaking.
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    \66\ A summary of this Background Ozone Science Assessment 
workshop is available at: https://www.wrapair2.org/pdf/BOSA_March_28-29_workshop_agenda.pdf. A related journal article is 
currently undergoing peer review.
    \67\ A work plan and list of publications is available on the 
website: www.htap.org.
    \68\ Details about these Health and Air Quality Applied Sciences 
Team workshops and projects are available on the website: https://haqast.org.
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    The EPA also in 2016 recently finalized revisions to the 
Exceptional Events Rule to further facilitate review and approval of 
exceptional events that contribute to USB, such as stratospheric ozone 
intrusions and wildfires (81 FR 68216; October 3, 2016). Guidance is 
currently available for demonstrations of exceptional events for high 
wind dust, and the EPA finalized guidance for ozone associated with 
wildfire events in September 2016.\69\ The EPA expects to make 
available similar guidance for stratospheric ozone intrusions by the 
end of 2018. However, the EPA is not revising the Exceptional Events 
Rule or guidance with this rulemaking.
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    \69\ Guidance documents and more information about exceptional 
events can be found at: https://www.epa.gov/air-quality-analysis/exceptional-events-rule-and-guidance.
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E. Additional Policies and Programs for Achieving Emissions Reductions

1. Multi-Pollutant Planning
    Increasingly, state air agencies are considering multi-pollutant 
emission reduction strategies. States have expressed interest in a 
number of those strategies, ranging from energy efficiency and 
renewable energy (EE/RE) programs to land use planning and travel 
efficiency programs. This section discusses EE/RE, and Sections E.2 and 
E.3 that follow discuss the latter programs.
    In recent years, states have expressed increased interest in EE/RE 
programs 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 NAAQS-related air pollutants such as 
NOX, PM2.5, and sulfur dioxide (SO2) 
and other air pollutants, such as hazardous air pollutants). 
Effectively assessing these approaches will require strong working 
relationships between state energy and environmental officials. As 
state public utility commissions (PUCs) 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.
    States and other authorities have requested the EPA's assistance in 
accounting for the emissions reductions achieved through EE/RE programs 
in NAAQS SIPs and tribal implementation plans (TIPs), and the EPA has 
responded to those requests by developing several resources, including 
the ``Roadmap for Incorporating EE/RE Programs and Policies in NAAQS 
SIPs/TIPs'' (released August 2012) \70\ and the AVoided Emissions 
geneRation Tool (AVERT), a tool for quantifying NOX, 
SO2 and CO2 avoided emissions (released February 
2014).\71\ 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.\72\
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    \70\ Roadmap for Incorporating EE/RE Programs and Policies in 
NAAQS SIPs/TIPs available at: https://www.epa.gov/sites/production/files/2016-05/documents/eeremanual_0.pdf.
    \71\ AVERT available at: http://www3.epa.gov/avert/.
    \72\Available at https://www.epa.gov/sites/production/files/2016-05/documents/appendixi_0.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 Sparse Matrix Operator Kernel 
Emissions formatting to incorporate the emission impacts into air 
quality models.
    The EPA recognizes that states may now have at their disposal other 
quantification tools. An update of the ``Air Emissions Inventory 
Guidance for Implementation of Ozone and Particulate Matter NAAQS and 
Regional Haze Regulations'' (released July 2017) provides examples of 
tools that states can use to quantify the power sector emissions and 
EE/RE.\73\ In this guidance, the EPA does not limit the types of tools 
states can use, so long as

[[Page 63028]]

states appropriately document their assumptions.
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    \73\ Available at: https://www.epa.gov/air-emissions-inventories/air-emissions-inventory-guidance-implementation-ozone-and-particulate.
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    State PUCs, primarily through their utilities, have in recent years 
been rapidly increasing resources devoted to EE programs. In the 5 
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.\74\ 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 
(RPS).\75\
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    \74\ American Council for an Energy-Efficient Economy (ACEEE) 
2013 State Energy Efficiency Scorecard (November 2013), available 
at: http://www.aceee.org/state-policy/scorecard/.
    \75\ U.S. EPA 2015. Energy and Environmental Guide to Action, 
Chapter 4 available at: https://www.epa.gov/statelocalenergy/energy-and-environment-guide-action-chapter-4-energy-efficiency-policies.
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    Also, state-level RE requirements have been implemented in 29 
states plus Washington, DC, representing all regions of the 
country.\76\ Between the years 2020 and 2030, many state-level RPS 
programs require electric utilities to serve from 15 to 40 percent of 
their retail sales with renewable power.\77\
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    \76\ 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.
    \77\ U.S. EPA. 2015 Energy and Environment Guide to Action, 
Chapter 5 available at: https://www.epa.gov/statelocalenergy/energy-and-environment-guide-action-chapter-5-renewable-portfolio-standards.
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    To further help states assess the effects of these programs, the 
EPA developed a counterfactual EE/RE scenario for two areas that were 
nonattainment for the 2008 ozone NAAQS, including the New York-New 
Jersey-Connecticut area.\78\ 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 \79\ will avoid 
over 24 tons per summer day of NOX in 2020, and the current 
state-level EE programs \80\ will avoid nearly 17 tons per summer day 
of NOX in 2020.\81\
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    \78\ 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 for this rulemaking.
    \79\ The 2020 RE requirements in each state are different and 
range from 20 percent to 30 percent.
    \80\ 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.
    \81\ 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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2. 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 website.\82\ 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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    \82\ 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.
3. Travel Efficiency
    Areas may also consider incorporating in their SIPs 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. 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 website.\83\
---------------------------------------------------------------------------

    \83\ See https://www.epa.gov/state-and-local-transportation/policy-and-technical-guidance-state-and-local-transportation.
---------------------------------------------------------------------------

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 ``Guidance on Preparing Enforceable 
Regulations and Compliance Programs for the 15 Percent Rate-of-Progress 
Plans'' (EPA-452/R-93-005, June 1993) \84\ 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 did not propose, and is 
not adopting, any additional specific regulatory provisions related to 
compliance and enforcement for implementing the 2015 ozone NAAQS, and 
received no adverse comments on the existing recommended approach and 
related guidance.
---------------------------------------------------------------------------

    \84\ Available at: http://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=00002TCM.txt.
---------------------------------------------------------------------------

G. Applicability of Final 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.\85\ The Tribal 
Authority Rule (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

[[Page 63029]]

Ozone NAAQS SIP Requirements Rule (78 FR 34209; June 6, 2013), tribes 
are not required to submit TIPs under the TAR. However, should a tribe 
choose to develop a TIP, this rule is intended to serve as a guide for 
addressing key implementation issues for areas 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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    \85\ 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. States need to incorporate 
Indian country emissions in their base emissions inventories if Indian 
country is part of an attainment or nonattainment area. Tribes and 
states should coordinate their planning activities as appropriate to 
ensure that neither is adversely affecting attainment of the NAAQS in 
the area as a whole. 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) 
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 
states and tribes with approved TAS 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 February 2014 ``OAR Handbook for Interacting with Tribal 
Governments'' and the ``EPA Policy on Consultation and Coordination 
with Indian Tribes.'' \86\ Consistent with these policies, the EPA 
intends to meet with tribes on activities potentially affecting the 
attainment and maintenance of the 2015 ozone NAAQS in Indian country, 
including our actions on SIPs. As such, it would be helpful for states 
to work with tribes whose land that is part of the same general air 
quality 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.
---------------------------------------------------------------------------

    \86\ Tribal guidance documents are available at: https://www.epa.gov/sites/production/files/2018-01/documents/oar_handbook_updated_1.24.18_.pdf and http://www.epa.gov/tribal/forms/consultation-and-coordination-tribes.
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VI. Environmental Justice Considerations

    The EPA believes this action does not have disproportionately high 
and adverse human health or environmental effects on minority, low-
income or indigenous populations because it does not negatively affect 
the level of protection provided to human health or the environment 
under the 2015 ozone NAAQS, which are set at levels to protect 
sensitive populations with an adequate margin of safety.\87\ These 
regulations help 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 do not 
adversely affect the health or safety of minority, low-income or 
indigenous populations.
---------------------------------------------------------------------------

    \87\ 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).
---------------------------------------------------------------------------

    Comment: One commenter on the proposed rulemaking stated that the 
implementation rule must identify specific measures directed to 
minority, low-income and/or indigenous people. The commenter noted that 
the EPA identified such measures in the PM2.5 SIP 
Requirement Rule. The commenter requests that the EPA require states to 
utilize specific measures when developing attainment plans, updating 
yearly monitoring plans and initiating the permitting process for 
overburdened communities.
    Response: The EPA is not making any changes to its proposed 
approach in response to the commenter's request that the EPA require 
states to utilize specific measures directed to minority, low-income 
and indigenous people to help address ground-level ozone. In the CAA's 
framework of cooperative federalism, states are primarily responsible 
for developing plans for achieving NAAQS in areas within their 
jurisdiction, based on planning rules and guidance promulgated by the 
EPA. These planning requirements include (but are not limited to) 
provisions for implementing emissions controls, tracking progress 
toward attainment and monitoring and reporting air quality data, with 
the overarching goal of attaining and maintaining the NAAQS as 
expeditiously as practical, but no later than the CAA's maximum 
attainment date. In the PM2.5 SIP Requirements Rule, the EPA 
encouraged states to consider various tools to help users identify 
areas with minority and/or low-income populations, potential 
environmental quality issues, a combination of environmental and 
demographic indicators that is greater than usual and other factors 
that may be of interest. The EPA included these tools in the 
PM2.5 SIP Requirements Rule because areas designated 
nonattainment for the PM2.5 standards can contain sources of 
directly emitted pollutants that can have adverse impacts on a local 
neighborhood scale. By contrast, elevated levels of ambient ozone are 
the result of secondary urban-scale atmospheric formation involving 
emissions from ubiquitous sources of ozone precursors (VOC and 
NOX) including motor vehicles, large and small industrial 
processes and consumer products which result in more regional scale 
impacts further down wind. The EPA encourages states to work with 
communities to develop ozone-related control strategies that most 
effectively reduce emissions that contribute to elevated ozone levels.

VII. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders 
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.

[[Page 63030]]

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

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

B. Executive Order 13771: Reducing Regulations and Controlling 
Regulatory Costs

    This action is not subject to Executive Order 13771 because this 
final rule is expected to result in no more than de minimis costs.

C. Paperwork Reduction Act (PRA)

    The information collection activities in this final 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 finalizing these implementing regulations for the 2015 
ozone NAAQS so that air agencies will know what CAA requirements apply 
to their nonattainment areas when the air agencies develop their SIPs 
or SIP revisions 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,\88\ the EPA assumed 57 nonattainment 
areas,\89\ some of which must prepare an attainment demonstration as 
well as submit an RFP and RACT SIP. The attainment demonstration 
requirement appears 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 appears in 40 CFR 51.1310, and the RACT SIP submission 
requirement appears in 40 CFR 51.1312, which implements CAA subsections 
172(c)(1) and 182(b)(2), (c), (d), and (e).
---------------------------------------------------------------------------

    \88\ Burden is defined at 5 CFR 1320.3(b).
    \89\ 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 are determined through the 
designations process.
---------------------------------------------------------------------------

    Air agencies with areas that have been previously designated 
nonattainment should already have information from many emission 
sources, as facilities should have provided this information to meet 1-
hour, 1997 and/or 2008 ozone NAAQS SIP requirements, operating permit 
program requirements and/or emissions reporting requirements.
    The annual burden for information collection averaged over the 
first 3 years of the 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) 
or approximately $107,000 per state for the estimated 23 state air 
agency respondents. The ICR Supporting Statement for the 2015 8-hour 
Ozone NAAQS Implementation Rule, EPA ICR No. 2347.03, provided in the 
docket, provides the details for the 23 state air agencies that would 
be required to provide the estimated 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 rulemaking 
requirements.
    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. When OMB 
approves this ICR, the agency will announce that approval in the 
Federal Register and publish a technical amendment to 40 CFR part 9 to 
display the OMB control number for the approved information collection 
activities contained in this final rule.

D. 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 and local 
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 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.

E. 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 imposes no enforceable duty on any state, 
local or tribal governments or the private sector. The CAA imposes the 
obligation for states to submit attainment plans to implement the ozone 
NAAQS. In this rule, the EPA is clarifying those requirements. 
Therefore, this action is not subject to the requirements of sections 
202, 203 and 205 of the UMRA.

F. 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.

G. 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 is required 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 tribes. The CAA and 
the TAR 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 there were no substantial direct impacts on tribes, 
consistent with the February 2014 ``OAR Handbook for Interacting with 
Tribal Governments,'' and the ``EPA Policy on Consultation and 
Coordination with Indian Tribes.'' the EPA briefed tribal officials 
during the development of this action.

H. 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

[[Page 63031]]

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 implements a previously promulgated health or safety-
based federal standard established pursuant to the CAA.

I. 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.

J. National Technology Transfer and Advancement Act (NTTA)

    This rulemaking does not involve technical standards.

K. 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.

L. Congressional Review Act (CRA)

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

M. Judicial Review

    Section 307(b)(1) of the CAA indicates which Federal Courts of 
Appeal have venue for petitions of review of final agency actions by 
the EPA under the CAA. This section provides, in part, that petitions 
for review must be filed in the U.S. Court of Appeals for the District 
of Columbia Circuit (i) when the agency action consists of ``nationally 
applicable regulations promulgated, or final actions taken, by the 
Administrator'' or (ii) when such action is locally or regionally 
applicable, if ``such action is based on a determination of nationwide 
scope or effect and if in taking such action the Administrator finds 
and publishes that such action is based on such a determination.''
    The EPA is determining that this rule for the 2015 ozone NAAQS SIP 
requirements is ``nationally applicable'' within the meaning of CAA 
section 307(b)(1). First, the rulemaking addresses implementation of 
the NAAQS that applies to all states and territories in the U.S. 
Second, the rulemaking addresses planning requirements for potential 
nonattainment areas in states across the U.S. that are located in 
various EPA regions and numerous federal circuits. Third, the 
rulemaking addresses a common core of knowledge and analysis involved 
in formulating the decisions and a common interpretation of the 
requirements of the CAA being applied to potential nonattainment areas 
in states across the country. Courts have found similar implementation 
rulemaking actions to be nationally applicable.\90\
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    \90\ See, e.g., Texas v. EPA, 2011 U.S. App. LEXIS 5654 (5th 
Cir. 2011) (finding SIP call to 13 states to be nationally 
applicable and thus transferring the case to the U.S. Court of 
Appeals for the D.C. Circuit in accordance with CAA section 
307(b)(1)).
---------------------------------------------------------------------------

    Under section 307(b)(1) of the Act, petitions for judicial review 
of this action must be filed in the United States Court of Appeals for 
the District of Columbia Circuit by February 4, 2019. Any such judicial 
review is limited to only those objections that are raised with 
reasonable specificity in timely comments. Filing a petition for 
reconsideration by the Administrator of this final rule does not affect 
the finality of this rule for the purposes of judicial review nor does 
it extend the time within which a petition for judicial review may be 
filed and shall not postpone the effectiveness of such rule or action. 
Under section 307(b)(2) of the Act, the requirements of this final 
action may not be challenged later in civil or criminal proceedings to 
enforce these requirements.

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 in 40 CFR Part 51

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

    Dated: November 7, 2018.
Andrew R. Wheeler,
Acting Administrator.
    For the reasons stated in the preamble, Title 40, Chapter I of the 
Code of Federal Regulations is amended as follows:

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

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

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

0
2. In Appendix A to subpart A of part 51: revise Table 1 to read as 
follows:

Appendix A to Subpart A of Part 51--Tables

 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.

[[Page 63032]]

 
(3) NOX.................................          >=2500  >=100.....................  >=100.
                                          ..............  ..........................  O3 (Serious) >=50.
                                          ..............  ..........................  O3 (Severe) >=25.
                                          ..............  ..........................  O3 (Extreme) >=10.
                                          ..............  ..........................  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(k)).

* * * * *

0
3. In Sec.  51.165, revise paragraph (a)(11) to read as follows:

Sec.  51.165   Permit requirements.

    (a) * * *
    (11) Interpollutant offsetting, or interpollutant trading or 
interprecursor trading or interprecursor offset substitution--The plan 
shall require that in meeting the emissions offset requirements of 
paragraph (a)(3) of this section, the emissions offsets obtained shall 
be for the same regulated NSR pollutant unless interprecursor 
offsetting is permitted for a particular pollutant as specified in this 
paragraph. (a)(3) of this section, the emissions offsets obtained shall 
be for the same regulated NSR pollutant unless interprecursor 
offsetting is permitted for a particular pollutant as specified in this 
paragraph.
    (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 
actual 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 an area-specific default ratio 
(default ratio) for the applicable ozone nonattainment area, 
established in regulations as part of the approved plan, or default IPT 
ratios for an applicable ozone nonattainment area established in 
advance by an air agency that are presumed to be appropriate for each 
permit application in the area, absent contrary information in the 
record of an individual permit application, or case-specific ratios 
established for individual permits.
    (B)(1) Where a state seeks to use a default IPT ratio that is not 
part of the approved plan, the plan shall include the following to 
authorize the development of a default ratio for a particular ozone 
nonattainment area, including a revised default ratio resulting from 
the periodic review required under paragraph (a)(11)(i)(B)(2) of this 
section:
    (i) A description of the model(s) that will be used to develop any 
default ratio;
    (ii) A description of the approach that will be used to analyze 
modeling data, ambient monitoring data, and emission inventory data to 
determine the sensitivity of an area to emissions of ozone precursors 
in the formation of ground-level ozone; and
    (iii) A description of the modeling demonstration that will be used 
to show that the default ratio provides an equivalent or greater air 
quality benefit with respect to ground level concentrations in the 
ozone nonattainment area than an offset of the emitted precursor would 
achieve.
    (2) The plan shall require that for any default ratio for ozone, 
the reviewing authority shall evaluate that ratio at least every 5 
years to determine whether current conditions support the continued use 
of such ratio.
    (C) The plan shall require that, for any case-specific permit ratio 
for ozone proposed by a permit applicant to be used for a particular 
permit, the following information shall be submitted to the reviewing 
authority to support approval of the ratio:
    (1) The description of the air quality model(s) used to propose a 
case-specific ratio; and
    (2) the proposed ratio for the precursor substitution and 
accompanying calculations; and
    (3) a modeling demonstration showing that such ratio(s) as applied 
to the proposed project and credit source will provide an equivalent or 
greater air quality benefit with respect to ground level concentrations 
in the ozone nonattainment area than an offset of the emitted precursor 
would achieve.
    (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.
* * * * *

0
4. In Sec.  51.1300 add paragraphs (f) through (q) to read as follows:

Sec.  51.1300  Definitions.

* * * * *
    (f) 2008 ozone NAAQS means the 2008 8-hour primary and secondary 
ozone NAAQS codified at 40 CFR 50.15.
    (g) Attainment year ozone season shall mean the ozone season

[[Page 63033]]

immediately preceding a nonattainment area's maximum attainment date.
    (h) 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.
    (i) Nitrogen Oxides (NOX) means the sum of nitric oxide 
and nitrogen dioxide in the flue gas or emission point, collectively 
expressed as nitrogen dioxide.
    (j) 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).
    (k) 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.
    (l) Reasonable further progress (RFP) means the emissions 
reductions 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.
    (m) 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).
    (n) 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.
    (o) Current ozone NAAQS means the most recently promulgated ozone 
NAAQS at the time of application of any provision of this subpart.
    (p) 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).
    (q) 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.

0
5. Adding Sec. Sec.  51.1304 through 51.1319 to subpart CC to read as 
follows:
Sec.
Subpart CC--Provisions for Implementation of the 2015 Ozone National 
Ambient Air Quality Standards
* * * * *
51.1304-51.1305 [Reserved]
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 [Reserved]
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 [Reserved]

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

* * * * *

Sec. Sec.  51.1304-51.1305   [Reserved]

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 the 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 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) 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 
for which an attainment demonstration is required pursuant to paragraph 
(a) or (b) of this section, the state must provide for implementation 
of all

[[Page 63034]]

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  [Reserved]

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 the 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, 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; and
    (B) Relies on either NOX or VOC emissions reductions (or 
a combination) to meet the requirements of paragraph (a)(2)(i)(A) 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 subject to RFP 
under CAA sections 172(c)(2) and 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 the first 6-year period after the baseline year and all 
remaining 3-year periods 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). 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 the EPA fully 
approved a 15 percent VOC ROP plan for a prior ozone NAAQS (as well as 
portions for which the 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 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 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 the EPA 
under the provisions of subpart A of this part. States may use an 
alternative baseline emissions inventory provided that the year 
selected corresponds with the year of the effective date of designation 
as nonattainment for that NAAQS. All states associated with a multi-
state nonattainment area must consult and agree on using the 
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(q).
    (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

[[Page 63035]]

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 RFP 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 nonattainment 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 nonattainment area designations, the state shall provide for 
implementation of such RACT as expeditiously as practicable, but no 
later than January 1 of the fifth 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 no later than the start of the attainment year ozone 
season 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; 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 
third 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) 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 or appropriate 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 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 as defined by Sec.  51.1300(p) 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 
emissions 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(q).
    (d) In the inventories required by paragraphs (a) and (b) of this 
section, the state shall report emissions from point sources according 
to the point source emissions thresholds of the Air Emissions Reporting 
Requirements, 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(q), 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.

[[Page 63036]]

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 nonattainment 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 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 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 nonattainment area designations, the state shall provide for 
implementation of RACT as expeditiously as practicable, but no later 
than January 1 of the fifth 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 no later than the start of the attainment year ozone 
season 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; 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 
third year after the associated SIP submission deadline or the 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 the 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 RACM, RFP 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, at which time the requirements no longer 
apply; or the EPA determines that the area has violated that NAAQS, at 
which time the area is again required to submit such plans.

Sec.  51.1319  [Reserved]

0
6. In appendix S to part 51, revise paragraphs IV.G.5. introductory, 
and IV.G.5(i) and remove and reserve section VII.
    The revisions 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 
interprecursor offsetting 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) A reviewing authority may choose to satisfy the offset 
requirements of paragraph IV.A, Condition 3 of this Ruling for 
emissions of the ozone precursors NOX and VOC by 
offsetting reductions of emissions of either precursor, if all other 
requirements contained in this Ruling for such offsets are also 
satisfied. For a specific permit application, if the implementation 
of IPT is acceptable by the reviewing authority, the permit 
applicant shall submit to the reviewing authority for approval a 
case-specific permit IPT ratio for determining the required amount 
of emissions reductions to offset the proposed emissions increase 
when considered along with the applicable offset ratio as specified 
in paragraphs IV.G.2 through 4 of this Ruling. As part of the ratio 
submittal, the applicant shall submit the proposed permit-specific 
ozone IPT ratio to the reviewing authority, accompanied by the 
following information:
    (a) A description of the air quality model(s) that were used to 
propose a case-specific ratio; and
    (b) The proposed ratio for the precursor substitution and 
accompanying calculations; and
    (c) A modeling demonstration showing that such ratio(s) as 
applied to the proposed project and credit source will provide an 
equivalent or greater air quality benefit with respect to ground 
level concentrations in the ozone nonattainment area than an offset 
of the emitted precursor would achieve.
* * * * *
[FR Doc. 2018-25424 Filed 12-4-18; 8:45 am]
 BILLING CODE 6560-50-P