believe that this approach makes the most sense for implementing the
2015 ozone NAAQS.
7. Relationship Between Implementation of the 2015 Ozone NAAQS and the
CAA Title V Permits Program
    The EPA is proposing to retain its current approach for
implementing the title V permit program for sources in areas designated
nonattainment for the current ozone NAAQS and subject to anti-
backsliding requirements for a prior ozone NAAQS. The final 2008 Ozone
NAAQS SIP Requirements Rule adopted an approach under which, following
revocation of the prior (1997) ozone NAAQS, major source thresholds for
title V would be the same as the major source thresholds applicable for
purposes of other requirements such as RACT and NNSR (80 FR 12307;
March 6, 2015). We are proposing to retain this approach for purposes
of implementing the 2015 ozone NAAQS, without revision.
    Under this proposed approach, following revocation of the 2008
ozone NAAQS, major source thresholds for title V would be the same as
the major

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

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

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

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

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

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

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

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

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

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

    \50\ Triennial emissions reporting periods are set by regulation
in the Air Emissions Reporting Requirements at 40 CFR part 51,
subpart A. The most recent and upcoming reporting years are 2014,
2017, 2020, 2023 and 2026, where the reports are due to the EPA by
December 31 of the calendar year that follows the reporting year.
The EPA's implementing regulations for the ozone NAAQS provide that
states may use the most recent triennial report period emissions
inventory to satisfy the nonattainment area reporting requirements
of CAA section 182(a)(3)(A). See 40 CFR 51.1115(b).
---------------------------------------------------------------------------

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

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

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

    \51\ For purposes of this preamble discussion,
``reclassification'' is assumed to encompass nonattainment areas
being reclassified, attainment areas being redesignated as
nonattainment and assigned an initial Moderate-or-higher
classification, and new OTR assignments. Similarly, ``RACT SIP
revision'' is assumed to encompass initial RACT SIPs triggered by an
initial area classification of--or reclassification to--Moderate or
higher.
---------------------------------------------------------------------------

    To address these reclassification scenarios, we are proposing
default submission and implementation deadlines for resulting SIP
revisions. The EPA is proposing that, following a reclassification
action, RACT SIP revisions be submitted no later than 24 months after
the effective date of reclassification, or the deadline established by
the Administrator in the action reclassifying an area. We are proposing
that the RACT SIP revisions be implemented as expeditiously as
practicable, but no later than the start of the ozone season attainment
year associated with the area's new attainment deadline, or January 1
of the third year after the associated SIP revision submittal deadline,
whichever is earlier. We are also proposing that the Administrator
would retain existing

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

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

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

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

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

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

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

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

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

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

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

    \55\ The EPA's prior guidance concerning the use of IPT to
satisfy the NNSR requirements for emissions offsets was contained in
a 2001 EPA document titled ``Improving Air Quality with Economic
Incentive Programs'' (January 2001). The EPA's policy on IPT for
ozone, when finalized through this rulemaking, will supersede the
information contained in that earlier document specifically with
respect to IPT.
---------------------------------------------------------------------------

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

offset requirements are based largely on Part D of title I of the CAA's
nonattainment requirements. These existing requirements include the
statutory offset ratios applicable in specific ozone nonattainment
areas (based on an area's classification for ozone), geographic
restrictions as to where creditable emissions reductions may be
obtained, and other criteria concerning the creditability of emissions
reductions to be used as offsets.
    A key component of an ozone IPT program for any ozone nonattainment
area is an IPT ratio.\56\ An IPT ratio is intended to ensure that the
substitution of one ozone precursor for another in an offset
transaction, substantiated by modeling or other technical
demonstration, provides an equivalent or greater air quality benefit
for ozone concentrations in the ozone nonattainment area. The EPA is
proposing that air agencies submit to the EPA as part of a plan that
must be approved by the Administrator: (1) Their ozone IPT provisions,
including the default IPT ratio(s) where applicable; (2) a description
of the air quality model(s) that have been used to develop any default
ratio(s); and (3) an accompanying modeling demonstration that such
ratio(s) provide an equivalent or greater air quality benefit for ozone
concentrations in the ozone nonattainment area. The EPA recommends that
each air agency implementing an ozone IPT program consult with the
appropriate EPA Regional office as the air agency develops a modeling
protocol to establish IPT ratios for a particular nonattainment area.
The EPA seeks comment on the proposed contents of the plan submission
and the approach for establishing area-specific default IPT ratios.
---------------------------------------------------------------------------

    \56\ The IPT ratio is separate and distinct from the statutory
ratios contained in the CAA and associated with area classifications
for ozone nonattainment areas. Both ratios must be applied in
determining the appropriate emissions offset that must be applied
for a particular offset transaction.
---------------------------------------------------------------------------

    The EPA proposes to provide flexibility for air agencies to
incorporate IPT ratios into their IPT programs for ozone nonattainment
areas.\57\ As stated in the 2008 PM2.5 NSR rulemaking, the
EPA believes the flexibility provided by this policy allows air
agencies and sources to take into account the role that ozone
precursors play in the formation of ground-level ozone in specific
ozone nonattainment areas due to the specific terrain, local and
regional source emissions mixture, and meteorological conditions that
exist in each area, and to select the most cost-effective manner to
obtain the offsets necessary to ensure that air quality improves. This
flexibility will also be beneficial where offsets for one particular
precursor are scarce in a particular area. The goal of the CAA is to
have air quality that is healthy, i.e., meeting the NAAQS, and there is
a strong principle in the CAA that air agencies have discretion to
choose from a range of options in designing plans to meet that goal,
which may include the choice to use the most cost-effective measures to
get there.
---------------------------------------------------------------------------

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

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

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

3. Authority To Establish Ozone NNSR IPT
    The EPA previously authorized IPT to satisfy the NNSR offset
requirement for PM2.5 \59\ in its NNSR regulations pursuant
to the CAA. The EPA continues to believe that the CAA accommodates the
use of technically supported IPT to satisfy the NNSR offset
requirement.\60\ Section 173(c)(1) of the CAA states that the NNSR
offset requirement shall ``assure that the total tonnage of increased
emissions of the air pollutant from the new or modified source shall be
offset by an equal or greater reduction, as applicable, in the actual
emissions of such air pollutant from the same or other sources in the
area.'' Section 302(g) of the CAA defines ``air pollutant'' to include
``. . . any precursors to the formation of any air pollutant, to the
extent the Administrator has identified such precursor or precursors
for the particular purpose for which the term `air pollutant' is
used.'' (Emphasis added).
---------------------------------------------------------------------------

    \59\ The EPA notes that this proposal concerns only IPT for
ozone. Accordingly, this action does not affect the existing
requirements concerning PM2.5 IPT.
    \60\ See 73 FR 28321, 28340 and 28347 (May 16, 2008).
---------------------------------------------------------------------------

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

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

    \61\ The EPA does not propose in the regulations to require
permitting authorities to use the data or methods described in the
TGD.
---------------------------------------------------------------------------

    In addition, in light of proposed changes to EPA's Guideline for
Air Quality Models, published as Appendix W to 40 CFR part 51, which
provide greater clarity regarding the use of

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

G. Emissions Inventory and Emissions Statement Requirements

1. Background and Summary of Proposal
    The EPA is proposing to clarify its emissions inventory and
emissions statement requirements in the context of this action by
adding 40 CFR 51.1315. CAA sections 182(a)(1) and 182(a)(3)(A) require
states to submit emissions inventories to the EPA. To clarify these
statutory requirements within the context of implementing the 2008
ozone NAAQS, the EPA added 40 CFR 51.1115 (80 FR 12264, 12314; March 6,
2015). These statutory and regulatory authorities do not address the
associated emissions statement requirements under CAA section
182(a)(3)(B). For purposes of the 2015 ozone NAAQS we are proposing to
add 40 CFR 51.1315, which will clarify requirements for the emissions
inventories and emissions statements required by CAA sections
182(a)(1), 182(a)(3)(A), and 182(a)(3)(B), respectively. While the
proposed 40 CFR 51.1315 is similar to the existing 40 CFR 51.1115,
these provisions are not identical, as discussed later. Moreover, we
are also clarifying in this preamble how air agencies demonstrate
compliance with CAA section 182(a)(3)(B) in the context of the 2015
ozone NAAQS.
2. Emissions Inventories
    The emission inventory requirements for the 2008 ozone NAAQS, found
at 40 CFR 51.1115, describe the criteria and timing for base year and
periodic inventories required under CAA sections 182(a)(1) and
182(a)(3)(A), respectively. For reference, the preamble to the final
2008 Ozone NAAQS SIP Requirements Rule provides an extensive discussion
of the EPA's rationale and approach for emission inventories (80 FR
12289; March 6, 2015). In general, we provided that air agencies may
rely, when appropriate, on their 3-year cycle inventory as described by
the Air Emissions Reporting Requirements rule (AERR, codified in 40 CFR
51, subpart A) to meet the 182(a)(3)(A) periodic inventory obligations,
with additional requirements for the reporting of ozone season day
emissions and treatment of partial-county inventories.\62\
---------------------------------------------------------------------------

    \62\ States should consult the latest version of the guidance
document titled ``Emission Inventory Guidance for Implementation of
Ozone and Particulate Matter National Ambient Air Quality Standards
(NAAQS) and Regional Haze Regulations,'' EPA-454/R-05-001 (latest
final November 2005; revised draft April 2014) and any subsequent
updates to that guidance that the EPA makes available at: https://www.epa.gov/air-emissions-inventories/emissions-inventory-guidance-implementation-ozone-and-particulate-matter.
---------------------------------------------------------------------------

    To support the periodic emissions inventory requirement, the EPA is
proposing revisions to the AERR point source reporting thresholds in
AERR Table 1 (40 CFR 51, subpart A, appendix A) to be consistent with
the major source thresholds for ozone nonattainment areas. These
reporting thresholds are in tons of potential emissions per year. The
existing AERR Table 1 includes Moderate area thresholds of 100 tpy for
NOX and VOC, which are the same as the triennial thresholds
for all areas. The existing AERR table also includes lower VOC
thresholds for the Serious, Severe, and Extreme areas of 50, 25 and 10
tpy. With this proposed revision, the AERR table would be updated to
also explicitly include these same Serious, Severe and Extreme area
thresholds for NOX. The same thresholds as have existed for
VOC also apply for NOX, consistent with definition of
``major source'' in both 40 CFR 70.2 and 40 CFR 71.2. In addition, the
VOC and NOX thresholds also depend on whether the source is
within an OTR in accordance with CAA 184(b)(2). Thus, the EPA proposes
to include in the AERR table a 50 tpy potential-to-emit (PTE) VOC
threshold for sources within an OTR and a 50 tpy PTE NOX
threshold for sources both within an OTR and within a Moderate ozone
nonattainment area. The latter requirement applies the same definition
noted above in 40 CFR 70.2 and 40 CFR 71.2. Finally, this proposal
removes the lower 100 tpy PTE carbon monoxide (CO) threshold from
Appendix A for ozone nonattainment areas because there is no major
source threshold for CO in the current or proposed implementing
regulations for the ozone NAAQS. The EPA notes that these proposed
revisions are technical corrections, and we are not proposing or
accepting comment on any substantive revisions to the AERR itself.
    Air agencies are advised to check the EPA Web site for the
currently approved mobile source models and to consult with the EPA
Office of Transportation and Air Quality and their Regional office to
determine the versions of models to use for their SIPs for the 2015
ozone NAAQS. MOVES2014a, which incorporates both onroad and nonroad
emissions estimates, is the most recently approved model for states
other than California. The model and additional information are
available at: http://www.epa.gov/otaq/models/moves/index.htm. Other
appropriate methods should be used to estimate emissions of nonroad
sources not included in the model. For California, consult with the EPA
Region 9 for information on the latest approved version of the EMFAC
(Emissions FACtors) model. EMFAC2014 is the most recently approved
model.
    The EPA is proposing to otherwise adopt the same emission inventory
requirements for the 2015 ozone NAAQS, based on the current approach
articulated in the final 2008 Ozone NAAQS SIP Requirements Rule.
3. Emissions Statements
    For nonattainment areas, air agencies must develop, and include in
their SIP, emission reporting programs for certain VOC and
NOX sources in accordance with CAA section 182(a)(3)(B). The
required state program defines how air agencies obtain emissions data
directly from certain facilities, and these data, along with other
information, are then reported to the EPA as part of SIP inventories
required by CAA sections 182(a)(1) and 182(a)(3)(a). This state program
is generally referred to as an emissions statement regulation, and it
outlines how certain facilities must report emissions and facility
activity data to an air agency, typically a state. Reports submitted to
air agencies must be accompanied by ``a certification that the
information contained'' in the report is ``accurate to the best
knowledge'' of the facility.\63\ To properly implement the emissions
reporting requirements, smissions statement regulations should be
coordinated carefully with the data

elements that are required by the EPA (existing requirements at 40 CFR
51.1115 and proposed at 40 CFR 51.1315). An air agency must submit the
emissions statement regulation required by CAA section 182(a)(3)(B), or
a written statement certifying a previously-approved regulation, to the
EPA as a SIP revision for approval (see Section III.A.2 of this
preamble). CAA section 110, in conjunction with 40 CFR 51.102, 103 and
Appendix V, establishes the procedure for submitting a SIP revision.
---------------------------------------------------------------------------

    \63\ Additional details on developing emissions statement
regulations can be found in the guidance document titled ``Guidance
on the Implementation of an Emission Statement Program (DRAFT),''
(July 1992) available at: https://www.epa.gov/air-emissions-inventories/implementation-emission-statement-program.
---------------------------------------------------------------------------

V. Additional Considerations

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

A. Managing Emissions From Wildfire and Wildland Prescribed Fire

    The final 2008 Ozone NAAQS SIP Requirements Rule discussed the
large contribution that wildfire can make to air pollution (including
ozone), and wildfire's threat to public safety. The rule also
recognized that this effect can be mitigated through management of
wildland vegetation, including through prescribed fire. Such mitigation
can help manage the contribution of fires to ozone levels in
nonattainment areas. Therefore, the EPA recommended as guidance but not
as a requirement of the final rule, if wildfire impacts are significant
and contribute to exceedances of the standard, then air agencies should
consider RACM for wildfires (which RACM could include a required
program of prescribed fires). The EPA also recommended that air
agencies should consider RACM for managing emissions from prescribed
fires (including those prescribed fires conducted to reduce future
wildfire emissions). The rule noted that information is available from
the U.S. Department of the Interior (DOI) and the U.S. Department of
Agriculture (USDA) Forest Service on smoke management programs and
basic smoke management practices (BSMP). See 80 FR 12282.
    More recently, in its proposed implementation rule for the
PM2.5 NAAQS, the EPA proposed to recommend as guidance, but
not as a requirement of the final rule, if wildfire impacts are
significant, and contributed to exceedances of the standard, then air
agencies should consider RACM for wildfires (which RACM could include a
required program of prescribed fires). The EPA also proposed to
recommend that air agencies should consider RACM for managing emissions
from prescribed fires (including those prescribed fires conducted to
reduce future wildfire emissions). The proposal noted that information
is available from the DOI and the USDA Forest Service on smoke
management programs and BSMP. The EPA requested comment on the concept
of, and practical considerations associated with RACM for wildfire and
RACM for prescribed fire, including such issues as how such measures
can be characterized in the emissions inventory and attainment
demonstration and made federally enforceable for adoption in a SIP (80
FR 15372; March 23, 2015). Upon consideration of public comments and
further consultation with other federal agencies, the EPA recommended,
as guidance for air agencies as they implement the final
PM2.5 implementation rule, that air agencies follow a
different approach to addressing RACM for wildland fire than the
approach that the EPA proposed to recommend (81 FR 58038-39; August 24,
2016). We are proposing the same recommended approach for purposes of
implementing the 2015 ozone NAAQS, as discussed in this preamble.
    Before explaining this recommendation further, the EPA wishes to
clarify that the recommendation is focused on wildland fire management.
There are other uses of prescribed fire and other types of burning that
occur in nonattainment areas, or that affect downwind nonattainment
areas, such as burning of land clearing debris, agricultural burning,
and burning of logging slash on land where the primary purpose of the
logging is for commercial timber sale.\64\ The challenges with applying
the traditional nonattainment planning framework that are raised in
this discussion are particular to wildland fire, and the EPA believes
that addressing these other uses of prescribed fire does not present
nearly the same level of challenge, and thereby can still be
accommodated within the nonattainment planning framework. For example,
where these other types of burning currently contribute to ozone levels
in a nonattainment area, air agencies may, with an adequate technical
demonstration, be able to take credit for reductions resulting from
improvement in smoke management techniques for these types of
prescribed fire where the improvement results in a demonstrated
reduction in impacts in the nonattainment area. The remainder of this
discussion is not meant to address these categories, and is instead
focused on prescribed fire on wildlands.
---------------------------------------------------------------------------

    \64\ The EPA notes that some wildland logging operations are
conducted for the same purposes as prescribed fire (e.g., reducing
fuel load, ecosystem benefits). The fact that some of the removed
trees may be sold as timber does not make commercial timber sale the
primary purpose of such operations.
---------------------------------------------------------------------------

    The EPA also wants to clarify that it is not the intention to in
any way discourage federal, state, local or tribal agencies or private
land owners from taking situation-appropriate steps to minimize impacts
from prescribed fire emissions on wildland. The EPA encourages all land
owners and managers to apply appropriate BSMP to reduce emissions from
prescribed fires, especially where an air agency has determined that
prescribed fires are a significant source affecting air quality. The
EPA understands that the federal land managers (FLMs) apply these
measures routinely and will be available to consult with other agencies
and private parties interested in doing the same.
    However, for several reasons, the EPA does not believe it would be
effective policy or technically appropriate to recommend that control
measures for wildland fire be adopted into the SIP as enforceable
measures and credited for emissions reductions (of ozone and
precursors) that would help the area attain the standard.\65\ Instead,
EPA recommends that ozone nonattainment plans (and in particular the
attainment demonstrations) not expressly account for expected air
quality changes over the planning period resulting from changes in the
use of wildland prescribed fire to reduce future wildfires, or air
quality changes over the planning period resulting from changes in
wildland fire emissions due to a program of prescribed fire or due to
any other cause including climate change. In most cases, state
attainment demonstration modeling should assume that wildland

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.
---------------------------------------------------------------------------

    \65\ These reasons include concerns raised by commenters about
the difficulties associated with requiring or even encouraging
states to incorporate wildland fire emissions into existing
nonattainment planning procedures and practices under the CAA; high
year-to-year variability and unpredictability with emissions from
wildland fires; uncertainty in the amount of credit to give for
reduced wildfire within the planning period and in the amount of
benefit that exists after accounting for increases in prescribed
fires within the planning period; and finally, the fact that air
quality data actually influenced by fire events may ultimately be
excluded under the provisions of the Exceptional Events Rule (40 CFR
50.14).
---------------------------------------------------------------------------

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

B. Transportation Conformity and General Conformity

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

conformity regulations in November 1993 (40 CFR part 51, subpart W and
40 CFR part 93, subpart B). Subsequently, the EPA finalized revisions
to the general conformity regulations on April 5, 2010 (75 FR 17254).
The general conformity program ensures that federal actions not covered
by the Transportation Conformity Rule will not interfere with the SIP.
General conformity also fosters communications between federal agencies
and state and local air quality agencies, provides for public
notification of and access to federal agency conformity determinations
and allows for air quality review of individual federal actions. More
information on the general conformity program is available at http://www3.epa.gov/airquality/genconform/.
2. Why is the EPA discussing transportation and general conformity in
this proposed rulemaking?
    The EPA is discussing transportation and general conformity in this
proposed rulemaking in order to provide affected parties with
information on when conformity must be implemented after nonattainment
areas are designated for the 2015 ozone NAAQS. The information
presented here is consistent with existing conformity regulations and
statutory provisions that are not addressed by this ozone
implementation rulemaking. Affected parties include state and local
transportation and air quality agencies, MPOs, and federal agencies
including the U.S. Department of Transportation (DOT), the U.S.
Department of Defense, the DOI and the USDA.
3. When would transportation and general conformity apply to areas
designated nonattainment for the 2015 ozone NAAQS?
    Transportation and general conformity will apply 1 year after the
effective date of nonattainment designations for a new or revised ozone
NAAQS including the 2015 ozone NAAQS. This is because CAA section
176(c)(6) provides a 1-year grace period from the effective date of
initial designations for any new or revised NAAQS before transportation
and general conformity apply in areas newly designated nonattainment
for a specific pollutant and NAAQS. The grace period applies to newly
designated nonattainment for a new or revised ozone NAAQS including the
2015 ozone NAAQS even if the area had been designated nonattainment for
a prior ozone NAAQS. With regard to general conformity, the EPA's April
2010 revisions to its general conformity regulations (see 75 FR 17277;
April 5, 2010) apply the same 1-year grace period to all new or revised
NAAQS--including the 2015 ozone NAAQS--for purposes of general
conformity.
    With regard to transportation conformity, the conformity grace
period will apply to all areas designated nonattainment for a new or
revised ozone NAAQS including the 2015 ozone NAAQS. The requirements
differ depending on whether the nonattainment area includes any part of
an MPO designated under 23 United States Code (U.S.C.) section 134.
Within 1 year after the effective date of the initial nonattainment
designation for a given pollutant and NAAQS, the MPOs and DOT must make
a conformity determination with regard to that pollutant and standard
for all of the metropolitan transportation plans and TIPs in the
nonattainment area. The conformity requirements for surrounding ``donut
areas,'' including the application of the 1-year conformity grace
period, are generally the same as those for metropolitan areas.\66\ If,
at the end of the grace period, the MPO and the DOT have not made a
transportation plan and TIP conformity determination for the relevant
pollutant and standard, the area would be in a conformity ``lapse.''
During a conformity lapse, only certain projects can receive additional
federal funding or approvals to proceed.\67\ The practical impact of a
conformity lapse will vary from area to area. Finally, the 1-year
conformity grace period also applies to project level conformity
determinations.
---------------------------------------------------------------------------

    \66\ For the purposes of transportation conformity, a ``donut''
area is the geographic area outside a metropolitan planning area
boundary, but inside a designated nonattainment or maintenance area
boundary that includes an MPO (40 CFR 93.101).
    \67\ During a conformity lapse, only the following projects can
receive additional federal approvals and funding:
    1. Projects that are exempt from transportation conformity such
as elimination of at-grade railroad crossings, repaving roadways,
widening narrow pavements and reconstructing bridges as long as new
travel lanes are not added because they are exempt from conformity;
and
    2. Transportation control measures included in approved SIPs
because these projects provide emissions reductions toward attaining
or maintaining the NAAQS.
    Additionally, any project or project phase that was funded or
approved prior to a lapse may proceed but no additional funding or
approval decisions may be made until the lapse is ended.
---------------------------------------------------------------------------

    Isolated rural nonattainment areas are areas that do not contain or
are not part of an MPO (40 CFR 93.101).\68\ Conformity requirements for
isolated rural nonattainment areas can be found at 40 CFR 93.109(g).
One year after the effective date of the initial nonattainment
designation for a given pollutant and NAAQS, conformity requirements
with regard to that pollutant and standard would apply in any
nonattainment areas that are isolated rural areas. Per the
Transportation Conformity Rule, at the point that a transportation
project in an isolated rural area needs federal funding or approval,
the project sponsor (e.g., the state DOT) would prepare the
documentation required for the transportation conformity determination,
including a regional emissions analysis. The Federal Highway
Administration and Federal Transit Administration could then make the
transportation conformity determination. This conformity determination
may occur significantly after the 1-year grace period has ended. See
the EPA's July 1, 2004, final rule for further background on how the
EPA has implemented this conformity grace period in metropolitan, donut
and isolated rural areas (69 FR 40008-14).\69\
---------------------------------------------------------------------------

    \68\ An isolated rural nonattainment area as defined in the
transportation conformity rule is distinct from a CAA section 182(h)
rural transport area. An isolated rural area for transportation
conformity purposes is a nonattainment area that does not contain or
is not part of any metropolitan planning area as designated under
federal transportation planning regulations. (40 CFR 93.101) A rural
transport area as defined in CAA section 182(h) is a nonattainment
area that is not adjacent to or part of any metropolitan statistical
area or consolidated metropolitan area, if one exists. Such an area
may be treated as a rural transport area if the Administrator finds
that sources of VOC and, if relevant, NOX emissions in
the area do not make a significant contribution to the ozone
concentrations measured in the area or other areas.
    \69\ Also, see the EPA's transportation conformity Web site for
more information, including EPA's ``Transportation Conformity
Guidance for 2008 Ozone NAAQS Nonattainment Areas'' at: http://www3.epa.gov/otaq/stateresources/transconf/2008naaqs.htm.
---------------------------------------------------------------------------

4. Would transportation and general conformity apply for the 2008 ozone
NAAQS once that NAAQS is revoked?
    The CAA only requires transportation and general conformity
determinations in areas that are designated nonattainment or
maintenance for a given pollutant and standard.\70\ As discussed in
Section IV.B of this preamble, the EPA is proposing two options for
revoking the 2008 ozone NAAQS. One option is to revoke the 2008 ozone
NAAQS for all purposes as has been done for the 1997 and 1-hour ozone
NAAQS one year after the effective date of designations for the 2015
ozone NAAQS. The second option is to revoke the 2008 ozone NAAQS in
areas that have always been designated attainment for that NAAQS and in
areas that have been redesignated to

attainment with an approved CAA section 175A maintenance plan. Under
the second option, the 2008 ozone NAAQS would be revoked in all
attainment areas for that NAAQS one year after the effective date of
designations for the 2015 ozone NAAQS. EPA will continue to redesignate
nonattainment areas for the 2008 ozone NAAQS after the initial
revocation. In those areas that are redesignated at a later date, the
2008 ozone NAAQS will be revoked on the effective date of the
redesignation but in no case sooner than 1 year after the effective
date of the designation for the 2015 ozone NAAQS for the area.
Therefore, transportation and general conformity would no longer apply
for purposes of the 2008 ozone NAAQS as of the time those standards
(and, thus, an area's designation for those standards) are revoked.
Accordingly, transportation and general conformity determinations would
no longer be required in existing 2008 ozone NAAQS nonattainment and
maintenance areas after the 2008 ozone NAAQS is revoked under either of
the proposed options. However, under option 2, the revocation for areas
designated as nonattainment for the 2008 ozone NAAQS would not occur
one year after the effective date of designations for the 2015 ozone
NAAQS. The revocation for these areas would only occur on the effective
date of their redesignation to attainment for the 2008 ozone NAAQS if
such redesignation were to occur.
---------------------------------------------------------------------------

    \70\ Maintenance areas are areas that have been redesignated to
attainment with an approved CAA section 175A maintenance plan.
---------------------------------------------------------------------------

    Under our current Transportation Conformity Rule, the latest
approved or adequate emission budgets for a prior ozone NAAQS (i.e.,
the 2008, 1997 or the 1-hour ozone NAAQS) would continue to be used in
transportation conformity determinations for the 2015 ozone NAAQS until
emission budgets are established and found adequate or are approved for
the 2015 ozone NAAQS (77 FR 14981, 14981; April 20, 1990). The use of
the latest approved or adequate motor vehicle emission budgets for a
prior ozone NAAQS as part of transportation conformity determinations
in nonattainment areas for the 2015 NAAQS until 2015 ozone motor
vehicle emissions budgets are available has been recognized as a
``control'' for purposes of defining anti-backsliding requirements as
discussed in section IV.B of this proposal. South Coast Air Qual. Mgmt.
Dist. v. EPA, 489 F.3d at 1248 (clarifying South Coast, 472 F.3d at
904-05). This requirement is already codified at 40 CFR 93.109(c)(2).
5. What impact will the implementation of the 2015 ozone NAAQS have on
an air agency's transportation and/or general conformity SIP?
    As long as the EPA does not make specific changes to its
transportation or general conformity regulations, air agencies should
not need to revise their transportation and/or general conformity SIPs.
The EPA is not proposing any changes to its transportation conformity
or general conformity regulations. Air agencies with new nonattainment
areas may need to revise conformity SIPs in order to ensure the state
regulations apply in any newly designated areas.
    However, if this is the first time that transportation conformity
will apply in a state, the air agency is required by the statute and
EPA regulations to submit a SIP revision that addresses three specific
transportation conformity requirements that address consultation
procedures and written commitments to control or mitigation measures
associated with conformity determinations for transportation plans,
TIPs or projects (40 CFR 51.390). Additional information and guidance
can be found in the EPA's ``Guidance for Developing Transportation
Conformity State Implementation Plans (SIPs)'' (http://www3.epa.gov/otaq/stateresources/transconf/policy/420b09001.pdf).
6. Are there any other impacts related to general conformity based on
implementation of the 2015 ozone NAAQS?
    As air agencies develop SIP revisions for the 2015 and future ozone
NAAQS, the agency recommends that state and local air quality agencies
work with federal agencies with large facilities (e.g., commercial
airports, ports and large military bases) that might take actions
subject to the general conformity regulations to establish an emissions
budget in the SIP for those facilities in order to facilitate future
conformity determinations under the conformity regulations. Such a
budget could be used by federal agencies in determining conformity or
identifying mitigation measures for particular projects at those
facilities, but only if the budget level is included and identified in
the SIP.
    In a few cases, tracts of land under federal management may also be
included in nonattainment and maintenance area boundaries. The role of
fire in these areas should be assessed and emissions budgets developed
in concert with those federal land management agencies. In such areas
the EPA encourages air agencies to consider in any baseline, modeling
and SIP attainment inventory used and/or submitted to include emissions
expected from projects subject to general conformity, including
emissions from wildland fire that may be reasonably expected in the
area. Where appropriate, air agencies may consider developing plans for
addressing wildland fuels in collaboration with land managers and
owners. Information is available from DOI and USDA Forest Service on
the ecological role of fire and on smoke management programs and
BSMP.\71\
---------------------------------------------------------------------------

    \71\ USDA Forest Service and Natural Resources Conservation
Service, Basic Smoke Management Practices Tech Note, October 2011,
http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1046311.pdf.
---------------------------------------------------------------------------

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

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

approximately 3 percent of the baseline emissions inventory. If these
adopted contingency measures are insufficient to attain the standard,
an air agency must conduct additional control measure development and
implementation for the area as necessary to correct the shortfall.
---------------------------------------------------------------------------

    \72\ The EPA acknowledges that the U.S. Court of Appeals for the
9th Circuit recently issued an opinion in Bahr v. EPA, No. 14-72327,
2016 U.S. App. LEXIS 16667 (9th Cir. Sept. 12, 2016), which rejected
EPA's longstanding interpretation of section 172(c)(9) in the
context of a SIP for particular matter standards that allowed states
to rely on control measures that are already in effect as a valid
means to meet the contingency measure requirement. The EPA is still
in the process of assessing and determining how to address the Bahr
decision, but does not currently plan to alter the Agency's
longstanding interpretation outside of the 9th Circuit, especially
in light of a prior decision from the U.S. Court of Appeals for the
5th Circuit upholding that interpretation. See Louisiana Envt'al
Action Network v. EPA, 382 F.3d 575 (5th Cir. 2004); see also 40 CFR
56.5(b).
    \73\ August 23, 1993, memorandum from Michael H. Shapiro, Acting
Assistant Administrator for Air and Radiation, to Regional Air
Directors, ``Guidance on Issues Related to 15 Percent Rate-of-
Progress Plans.'' Available at: http://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/19930823_shapiro_15pct_rop_guidance.pdf.
---------------------------------------------------------------------------

    Regarding content of the 1 year's worth of reductions covered by
the contingency measures, the EPA is proposing to continue to allow
these reductions of the contingency measures to be based entirely or in
part on NOX controls if the area has completed the initial
15 percent ROP VOC reduction required by CAA section 182(b)(1)(A)(i)
and an air agency's analyses have demonstrated that NOX
substitution (entirely or in part) would be effective in bringing the
area into attainment. The EPA will continue to allow the use of federal
measures providing ongoing reductions into the future to be used meet
contingency measure requirements for the 2015 ozone NAAQS, consistent
with the EPA's longstanding policy.
    With respect to Extreme ozone nonattainment areas, CAA section
182(e)(5) allows the agency to exercise discretion in approving Extreme
area attainment plans that rely, in part, on the future development of
new control technologies or improvements of existing control
technologies, where certain conditions are met. This discretion can be
applied as long as an air agency has demonstrated that: All RACM,
including RACT, have been included in the plan; the area's RFP
demonstration during the first 10 years after designation does not rely
on anticipated future technologies; and the air agency has submitted
enforceable commitments to timely develop and adopt contingency
measures to be implemented if the anticipated future technologies do
not achieve planned reductions. The EPA is proposing to continue to
allow air agencies to submit, for Extreme nonattainment areas,
enforceable commitments to develop and adopt contingency measures
meeting the requirements of 182(e)(5) to satisfy the requirements for
both attainment contingency measures in CAA sections 172(c)(9) and
182(c)(9). These enforceable commitments must obligate the air agency
to submit the required contingency measures to the EPA no later than 3
years before any applicable implementation date, in accordance with CAA
section 182(e)(5).\74\ We note that this does not, however, relieve air
agencies from obligations to submit contingency measures as required by
CAA sections 172(c)(9) and 182(c)(9) for periods in the first 10 years
after designation.
---------------------------------------------------------------------------

    \74\ For example, where a state intends to rely on CAA section
182(e)(5) commitments to satisfy the CAA section 182(c)(9)
contingency measure requirement for an RFP milestone in year 2027,
the commitments must obligate the state to submit adopted
contingency measures to the EPA no later than 2024 (i.e., 3 years
before RFP contingency measures for 2027 would be implemented).
---------------------------------------------------------------------------

D. International Transport and Background Ozone

    Most modeled ozone air quality values that exceed the NAAQS in the
United States (U.S.) are due primarily to emission sources within the
U.S. However, domestic ozone air quality can also be affected by
sources of emissions located outside of the U.S. These contributions to
U.S. ozone concentrations from sources outside of the U.S., which can
be from nearby sources in a bordering country or from sources many
thousands of miles away,\75\ can affect to varying degrees the ability
of some areas to attain and maintain the 2015 ozone NAAQS. The EPA will
continue to work with our domestic and international partners to better
understand the extent and implications of transboundary flows of air
pollutants and, where possible, to mitigate their impact on U.S.
domestic air quality.
---------------------------------------------------------------------------

    \75\ Observational and modeling studies have shown that
international ozone precursor emissions can lead to ozone formation
within the atmospheric boundary layer over far-upwind areas. When
meteorological conditions are favorable, this ozone can be
transported within the mid- and upper troposphere where ozone
lifetimes can exceed one week. Eventually, these ozone plumes can
mix down to the surface and contribute to local ozone concentrations
within the U.S. (Task Force on Hemispheric Transport of Air
Pollution, 2010).
---------------------------------------------------------------------------

    Congress recognized that some nonattainment areas may be impacted
not only by local sources of ozone or ozone precursor emissions, but
also sources of emissions from outside of the U.S. Through CAA section
179B, Congress provided the EPA with the authority to approve
attainment plans for areas that could attain the relevant NAAQS by the
statutory attainment date ``but for'' emissions emanating from outside
the U.S. When applicable, this CAA provision relieves states from
imposing control measures on emissions sources in the state's
jurisdiction beyond those necessary to address reasonably controllable
emissions from within the U.S. Specifically, CAA section 179B(a)
provides that the EPA shall approve an attainment plan for such an area
if: (i) The attainment plan meets all other applicable requirements of
the CAA, and (ii) the submitting state can satisfactorily demonstrate
that ``but for emissions emanating from outside the United States,''
the area would attain and maintain the relevant NAAQS. In addition, CAA
section 179B(b) applies specifically to the ozone NAAQS and provides
that if a state demonstrates that an ozone nonattainment area would
have timely attained the NAAQS by the applicable attainment date ``but
for emissions emanating from outside of the United States,'' then the
area can avoid extension of the ozone attainment dates pursuant to CAA
section 181(a)(5), the application of fee provisions of CAA section
185, and the mandatory reclassification provisions under CAA section
181(b)(2) \76\ for areas that fail to attain the ozone NAAQS by the
applicable attainment date. Section 179B, thus, provides an important
tool that provides states relief from the requirement to demonstrate
attainment--and from the more stringent planning requirements that
would result from failure to attain--in areas where, even though the
air agency has taken appropriate measures to address air quality in the
influenced area, emissions from outside of the U.S. prevent attainment.
---------------------------------------------------------------------------

    \76\ It is EPA's longstanding position that the Clean Air Act
contained an erroneous reference to section 181(a)(2) instead of
181(b)(2) in 179B(b). See ``State Implementation Plans; General
Preamble for the Implementation of Title I of the Clean Air Act
Amendments of 1990,'' 57 FR 13498, 13569 fn. 41 (April 16, 1992).
---------------------------------------------------------------------------

    In the 2008 ozone SIP Requirements Rule, the EPA stated that a
section 179B demonstration could include consideration of any emissions
from North American or intercontinental sources. (80 FR 12293). The EPA
also stated at that time that it did not believe use of section 179B
was limited to nonattainment areas adjoining international borders. Id.
at 12294. The EPA notes, however, that the science review conducted as
part of the 2015 ozone NAAQS suggests that the influence of
international sources on U.S. ozone levels will be largest in locations
that are in the immediate vicinity of Mexico or Canada (80 FR 65292,
65444; October 26, 2015). The EPA, therefore, anticipates that section
179B will most often be used by states with areas along the border with
Mexico and Canada. Historically, the EPA has used CAA section 179B
authority to approve attainment plans in the immediate vicinity of the
Mexican border, including El Paso, Texas,\77\ Imperial Valley,
California,\78\ and

Nogales, Arizona.\79\ Consistent with the particular showing required
by the statutory language, the EPA will consider section 179B
demonstrations on a case-by-case basis. The EPA asks for comment on
whether the opportunity for such a demonstration should be limited to
nonattainment areas adjoining international borders, and on any
technical and legal basis for determining whether it is appropriate to
have, or conversely whether it is appropriate not to have, such a
limitation.
---------------------------------------------------------------------------

    \77\ 59 FR 2532 (January 18, 1994); 68 FR 39457 (July 2, 2003);
69 FR 32450 (June 10, 2004).
    \78\ 66 FR 53106 (October 19, 2001), overturned in Sierra Club
v. EPA, et al., 352 F.3d 1186 (9th Cir. 2003).
    \79\ 77 FR 58962 (September 25, 2012).
---------------------------------------------------------------------------

    Even if an area is impacted by emissions from outside the U.S., CAA
section 179B does not affect the designations process.\80\ The
designations process is meant to protect public health and welfare.
Designating an area nonattainment for a particular NAAQS ensures that
the public is informed that the air quality in a specific area does not
meet the standard. Congress determined that in nonattainment areas,
there should be adequate safeguards to protect public health and
welfare. For example, Congress required such areas to have NNSR
permitting programs, to ensure that air quality is not further
degraded. Accordingly, areas with design values above the 2015 ozone
NAAQS will be designated nonattainment and will be classified with a
classification as indicated by actual ambient air quality. As a result
of designation and classification, the state is subject to the
applicable requirements, including NNSR, conformity, and other measures
prescribed for nonattainment areas by the CAA. Section 179B of the CAA
does not provide for any relaxation of mandatory emissions control
measures (including contingency measures) or the prescribed emissions
reductions; it only eliminates the obligation for an attainment
demonstration that demonstrates attainment and maintenance of the
NAAQS, which is conditioned upon the state meeting all other attainment
plan requirements,\81\ and voids certain consequences of an area's
failure to attain, including mandatory reclassifications.
---------------------------------------------------------------------------

    \80\ Monitoring data cannot be excluded for a determination of
whether an area has attained a NAAQS based solely on the fact the
data are affected by international transport. However, such data may
be excluded from consideration if they were significantly influenced
by exceptional events as described in CAA section 319(b). Where
international transport meets the criteria and procedural
requirements contained in the EPA's Exceptional Events Rule (40 CFR
50.14), it may be addressed by that rule. See 81 FR 68216 (October
3, 2016).
    \81\ For a more detailed description of attainment planning
requirements, see Section III.A of this preamble.
---------------------------------------------------------------------------

    CAA section 179B does not alter the CAA's general construct
expressed in subpart 1 of part D that states with nonattainment areas
are expected to adopt reasonable emissions controls to lessen emissions
of criteria pollutants to promote citizen health protection. The
construct ensures that states will take reasonable actions to mitigate
the public health impacts of exposure to ambient levels of pollution
that violate the NAAQS by imposing reasonable control measures on the
sources that are within the jurisdiction of the state regardless of
impacts from interstate or international emissions. The primary purpose
of part D of Title I of the CAA is to achieve emission reductions so
that people living in a nonattainment area receive the public health
protection intended by the NAAQS.
    Marginal ozone nonattainment areas are not generally required to
implement reasonably available control technology requirements under
subpart 2 of part D of Title 1 of the CAA. If an air agency were to
apply for treatment under CAA section 179B(b) to avoid mandatory
reclassification of a Marginal area after its failure to attain by the
applicable attainment date, an area could continue to remain Marginal
and, therefore, never implement reasonable emissions controls.
    The EPA believes that adopting an interpretation of CAA section
179B that would allow people to continue to be subjected to levels of
ozone above the NAAQS that a state could reasonably reduce--in this
case not to attainment level, but to a level below the current level--
would be antithetical to the objectives of the CAA. The EPA believes it
is appropriate for the Administrator to take this general construct of
the CAA into account in determining during the application of CAA
section 179B whether, ``to the satisfaction of the Administrator,'' an
area would have attained the ozone NAAQS by the applicable attainment
date but for emissions emanating from outside of the U.S. Accordingly,
the EPA is proposing and seeking comment on a requirement that all
demonstrations under CAA section 179B(b), regardless of an area's
classification (including nonattainment areas classified as Marginal),
must include a showing that the air agency adopted all RACM, including
RACT, for the area in accordance with CAA section 172(c)(1), 42 U.S.C.
7502(c)(1). Under this interpretation, if the air agency did not adopt
reasonable control measures before making a section 179B(b)
demonstration, it will be missing a critical component of the
demonstration that the area would have attained the ozone NAAQS by the
attainment date ``but for'' international impacts, namely a showing
that the area could otherwise attain by application of reasonable
controls on sources of emissions that are within the state's
jurisdiction.\82\ We are proposing to add new regulatory provisions at
40 CFR 51.1309 to establish that air agencies must also demonstrate
RACM for Marginal areas for treatment under CAA section 179B.
---------------------------------------------------------------------------

    \82\ With respect to the demonstration under CAA section
179B(a), regardless of the nonattainment area's classification,
where a plan can demonstrate that an area will attain the NAAQS by
the attainment date after adopting all reasonable control measures,
and, as such, would be potentially approvable by the EPA, such a
plan would not also be eligible for approval under CAA section
179B(a) by simply omitting these measures.
---------------------------------------------------------------------------

    The EPA encourages air agencies to coordinate with their EPA
regional office to identify approaches to evaluate the potential
impacts of international transport and to determine the most
appropriate information and analytical methods for each area's unique
situation. The EPA will also work with air agencies that are developing
attainment plans for which CAA section 179B is relevant, and ensure the
air agencies have the benefit of the EPA's understanding of
international transport of ozone and ozone precursors. Air agencies are
encouraged to consult with their EPA Regional office to establish
appropriate technical requirements for these analyses. The EPA invites
comment as to whether the EPA should develop technical guidance for the
``but for'' analysis in a section 179B demonstration, and invites
comment about which methodologies and tools would be most effective to
help states develop section 179B demonstrations.
    With respect to the larger issue of background ozone (or U.S.
background, (USB)), the EPA has solicited input from air agencies,
tribes, and interested stakeholders on aspects of USB that are relevant
to attaining the 2015 ozone NAAQS in a manner consistent with the
provisions of the CAA.\83\ To establish a common understanding and
foundation for discussion, the EPA released a white paper titled,
``Implementation of the 2015 Primary Ozone NAAQS: Issues Associated
with Background Ozone'' in December 2015, and held a workshop in
February 2016 to discuss information in the white paper.\84\
---------------------------------------------------------------------------

    \83\ For purposes of NAAQS implementation, the EPA considers
background ozone to be any ozone formed from sources or processes
other than U.S. manmade emissions of NOX, VOCs, methane
and CO.
    \84\ The white paper and other workshop details are available
at: https://www.epa.gov/ozone-pollution/background-ozone-workshop-and-information.

---------------------------------------------------------------------------

    Workshop attendees included representatives of state, local and
tribal air agencies, and other interested stakeholders. A general theme
among attendee comments was a concern that the EPA is underestimating
the magnitude and effects of USB, and that available policy solutions
do not provide meaningful relief from nonattainment designations in
affected areas.\85\ The EPA continues to refine and conduct its
national and global model simulations to better characterize USB, and
is actively evaluating the need for further guidance and/or rules to
address USB based on feedback received.
---------------------------------------------------------------------------

    \85\ A high-level summary of workshop feedback is available at:
https://www.epa.gov/sites/production/files/2016-03/documents/bgo3-high-level-summary.pdf. Additional written comments from interested
parties are located in a separate EPA docket at http://www.regulations.gov (Docket ID No. EPA-HQ-OAR-2016-0097).
---------------------------------------------------------------------------

    The EPA also recently finalized revisions to the Exceptional Events
Rule to further facilitate review and approval of exceptional events
that contribute to USB, such as stratospheric intrusions and wildfires
(81 FR 68216; October 3, 2016).

E. Additional Policies and Programs for Achieving Emissions Reductions

1. Multi-Pollutant Planning
    Increasingly, state air agencies are considering multi-pollutant
emission reduction strategies such as energy efficiency and renewable
energy (EE/RE) requirements as compliance options for CAA plans and EPA
encourages this multi-pollutant approach when assessing compliance
options for ozone RFP and attainment demonstration SIPs. Many states
are already implementing cost-effective EE/RE requirements that reduce
all types of power generation related emissions (including carbon
dioxide, NOX, PM2.5, SO2, and
hazardous air pollutants). Effectively assessing these approaches will
require strong working relationships between state energy and
environmental officials. As state Public Utility Commissions (PUC) and
state energy offices implement, increase the stringency of, or adopt
new EE/RE requirements, their expertise can assist air agencies to
incorporate the NOX emission impacts into ozone RFP and
attainment demonstration SIPs.
    The EPA discussed this approach more completely in the final Clean
Power Plan (CPP) \86\ and in an accompanying Technical Support Document
(TSD) titled ``Incorporating RE and Demand-Side EE into State Plan
Demonstrations.'' \87\ States would be able to use EE/RE requirements
as a compliance option in their state plans to meet the CPP's carbon
dioxide emission reduction targets for existing fossil-fired electric
generating units (EGUs), and achieve a co-benefit of reducing
NOX emissions that would be beneficial to managing ozone
formation.
---------------------------------------------------------------------------

    \86\ Carbon Pollution Emission Guidelines for Existing
Stationary Sources: Electric Utility Generating Units; Final Rule
(Clean Power Plan) (80 FR 64662; October 23, 2015). See, e.g., West
Virginia v. EPA, No. 15A773, Order at 1 (U.S. Feb. 9, 2016).
    \87\ U.S. EPA (October 2015) Clean Power Plan TSD: Incorporating
RE and Demand-Side EE Impacts into State Plan Demonstrations
available at: https://www.epa.gov/sites/production/files/2015-11/documents/tsd-cpp-incorporating-re-ee.pdf.
---------------------------------------------------------------------------

    The EPA has available several resources to help air agencies
incorporate these multi-pollutant strategies in NAAQS SIPs/TIPs.
Resources include the ``Roadmap for Incorporating EE/RE Programs and
Policies in NAAQS SIPs/TIPs'' \88\ (released August 2012) and the
AVoided Emissions geneRation Tool (AVERT), a tool for quantifying
NOX, SO2 and CO2 avoided emissions
\89\ (released February 2014). The Roadmap describes four pathways
(baseline emissions projection, control strategy, emerging/voluntary
measures, and weight of evidence determination) by which EE/RE policies
and programs could be included in a SIP. Each pathway is appropriate in
certain circumstances (existing vs. new EE/RE, control vs. voluntary
measures, etc.) and the Roadmap can help decision-makers consider their
options as they decide which pathway(s) to pursue for incorporating EE/
RE policies and programs into SIP/TIP demonstrations. The Roadmap's
Appendix I also presents several methods available for quantifying the
avoided NOX emissions from fossil fuel generation as a
result of electricity savings from EE/RE policy/program
implementation.\90\
---------------------------------------------------------------------------

    \88\ Roadmap for Incorporating EE/RE Programs and Policies in
NAAQS SIPs/TIPs available at: http://www3.epa.gov/airquality/eere/manual.html.
    \89\ AVERT available at: http://www3.epa.gov/avert/.
    \90\ Available at: http://www3.epa.gov/airquality/eere/pdfs/appendixI.pdf.
---------------------------------------------------------------------------

    The EPA's tool, AVERT, can help planners in quantifying the
emissions reductions that result from EE/RE policies and programs.
AVERT outputs are readily available for SMOKE formatting to incorporate
the emission impacts into air quality models.
2. Energy Efficiency/Renewable Energy Policies and Programs
    a. State-level EE/RE Requirements. State PUCs, primarily through
their utilities, have in recent years been rapidly increasing resources
devoted to EE programs. In the five years spanning 2006 to 2011,
budgets for EE programs more than tripled, from $1.6 billion to $5.9
billion. Additionally, EE spending is projected to continue to grow at
a substantial rate.\91\ As of March 2015, 23 states have mandatory
energy efficiency requirements, two states have voluntary targets, and
two states allow energy efficiency as a compliance option for their
renewable portfolio standard.\92\
---------------------------------------------------------------------------

    \91\ American Council for an Energy-Efficient Economy (ACEEE)
2013 State Energy Efficiency Scorecard. November 2013. Available at
http://www.aceee.org/state-policy/scorecard/.
    \92\ U.S. EPA 2015. Energy and Environmental Guide to Action,
Chapter 4 available at: http://www3.epa.gov/statelocalclimate/documents/pdf/GTA_Chapter_4.1_508.pdf.
---------------------------------------------------------------------------

    Also, state-level RE requirements have been implemented in 29
states plus Washington, DC, representing all regions of the
country.\93\ Between the years 2020 and 2030, many state-level
renewable portfolio standard (RPS) programs require electric utilities
to serve from 15 to 40 percent of their retail sales with renewable
power.\94\
---------------------------------------------------------------------------

    \93\ RE requirements include Renewable Portfolio Standards or
state-enacted RE requirements on a Mega-Watt (MW) basis. Database of
State Incentives for Renewables and Efficiency, March 2013.
Available at: http://www.dsireusa.org. Accessed January 3, 2016.
    \94\ U.S. EPA. 2015 Energy and Environment Guide to Action,
Chapter 5 available at: http://www3.epa.gov/statelocalclimate/documents/pdf/guide_action_chapter5.pdf.
---------------------------------------------------------------------------

    In an effort to examine the effects of these programs, EPA
developed a counterfactual EE/RE scenario for a couple of areas that
were nonattainment for EPA's 2008 ozone NAAQS, including the New York-
New Jersey-Connecticut area.\95\ In these illustrative examples the EPA
used AVERT to approximate the potential emissions that would have been
emitted into the atmosphere without current state-level EE/RE
requirements. For the New York-New Jersey-Connecticut area, the EPA
estimated that the current state-level RE requirements \96\ would avoid
over 24 tons per summer day of NOX in 2020, and the current
state-level EE

programs \97\ would avoid nearly 17 tons per summer day of
NOX in 2020.\98\
---------------------------------------------------------------------------

    \95\ This area encompasses eight counties in New York, 12
counties in New Jersey, and three counties in Connecticut. The EPA's
analysis is described in the Technical Support Document
``Demonstrating NOX Emission Reduction Benefits of State-
Level Renewable Energy and Energy Efficiency Policies'' available in
the docket.
    \96\ The 2020 RE requirements in each state are different and
range from 20 percent-30 percent.
    \97\ The EE programs used in each state are different.
Connecticut's estimated annual efficiency savings is 2.8 percent,
New York's target was 15 percent savings from baseline by 2015, and
New Jersey incentivized efficiency improvements through a funding
program of $265 million in FY2014.
    \98\ For context, the RFP plan for the New York-New Jersey-
Connecticut 1997 ozone NAAQS nonattainment area included a 2008
NOX emissions projection of 269 tons per summer day.
---------------------------------------------------------------------------

3. Land Use Planning
    Air agencies may also wish to consider strategies that foster more
efficient urban and regional development patterns as a long-term air
pollution control measure. Resources include the U.S. Department of
Housing and Development--DOT-EPA Partnership for Sustainable
Communities, as well as the policy and technical guidance documents on
land use and related travel efficiency available on the EPA's Office of
Transportation and Air Quality Web site.\99\ These documents provide
communities with the information they need to better understand the
link between air quality, transportation and land use, and how certain
land use policies have the potential to help local areas achieve and
maintain healthy air quality. The documents also include methods to
help communities account for the air quality benefits of their local
land use in their air quality plans.
---------------------------------------------------------------------------

    \99\ See http://www.epa.gov/otaq/stateresources/policy/pag_transp.htm.
---------------------------------------------------------------------------

    If wildfire impacts are significant in a particular area, air
agencies and communities may be able to lessen the impacts of wildfires
by working collaboratively with land managers and land owners to employ
various mitigation measures including taking steps to minimize fuel
loading in areas vulnerable to fire.
4. Travel Efficiency
    Areas may also consider incorporating travel efficiency strategies,
such as new or expanded mass transit options, commuter strategies,
system operations (e.g., ramp metering), pricing (e.g., parking fees,
congestion pricing, roadway tolls), real-time travel information and
multimodal freight strategies in their SIPs. The EPA has released
several documents that could be useful to air agencies that want to
evaluate emissions reductions from travel efficiency strategies. These
documents provide information on analysis methods and the potential
effectiveness of different combinations of travel efficiency measures
for reducing emissions. Additionally, the EPA has compiled a report
about transportation control measures that have been implemented across
the country for a variety of purposes, including reducing emissions
related to criteria pollutants. All of these documents are available on
the EPA's Office of Transportation and Air Quality Web site.\100\
---------------------------------------------------------------------------

    \100\ See http://www.epa.gov/otaq/stateresources/policy/pag_transp.htm.
---------------------------------------------------------------------------

F. Additional Requirements Related to Enforcement and Compliance

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

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

G. Applicability of Proposed Rule to Tribes

    Section 301(d) of the CAA authorizes the EPA to approve eligible
Indian tribes to implement provisions of the CAA on Indian reservations
and other areas within the tribes' jurisdiction.\102\ The TAR (40 CFR
part 49.1-49.11), which implements CAA section 301(d), sets forth the
criteria and process for tribes to apply to the EPA for eligibility to
administer CAA programs (40 CFR 49.6, 49.7). As discussed in detail in
the proposed 2008 Ozone NAAQS SIP Requirements Rule (78 FR 34209; June
6, 2013), tribes are not required to TIPs under the TAR. However,
should a tribe choose to develop a TIP, this proposed rule is intended
to serve as a guide for addressing key implementation issues for their
area of Indian country, particularly for any areas of Indian country
that may be designated as nonattainment areas separate from surrounding
state areas.
---------------------------------------------------------------------------

    \102\ On January 17, 2014, the United States Court of Appeals
for the District of Columbia Circuit issued a decision vacating the
EPA's 2011 rule titled ``Review of New Sources and Modifications in
Indian Country'' (76 FR 38748) with respect to non-reservation areas
of Indian country (See, Oklahoma Department of Environmental Quality
v. EPA, 740 F.3d 185 (D.C. Cir. 2014)). Under the court's reasoning,
with respect to CAA SIPs, a state has primary regulatory
jurisdiction in non-reservation areas of Indian country (i.e.,
Indian allotments located outside of reservations and dependent
Indian communities) within its geographic boundaries unless the EPA
or a tribe has demonstrated that a tribe has jurisdiction over a
particular area of non-reservation Indian country within the state.
---------------------------------------------------------------------------

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

    \103\ Tribal guidance documents are available at: http://www.epa.gov/tribal/forms/consultation-and-coordination-tribes.

---------------------------------------------------------------------------

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

VI. Environmental Justice Considerations

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

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

VII. Statutory and Executive Order Reviews

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

    This action is a significant regulatory action that was submitted
to OMB for review. Any changes made in response to OMB recommendations
have been documented in the docket.

B. Paperwork Reduction Act (PRA)

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