otherwise comply with CAA requirements. Commenters also state that
EPA's broader point about states' discretion is also flawed because the
cases it selectively relies upon hold that SIPs must not only provide
for timely attainment and maintenance of NAAQS but also satisfy CAA
section 110's other general requirements.
    Commenters state that in the final SIP call, EPA noted several
cases, including Mich. Dep't of Envtl. Quality v. Browner, 230 F.3d 181
(6th Cir. 2000), and US Magnesium, LLC v. EPA, 690 F.3d 1157 (10th Cir.
2012), where courts upheld EPA action finding that SSM exemptions in
SIPs are inappropriate and point to EPA's prior statement
characterizing these decisions as confirming the requirement for
continuous compliance and prohibiting exemptions for excess emissions
during SSM events.
    Commenters state that none of the June 5, 2019, NPRM's policy or
structural arguments about a ``fundamentally different regime'' in
section 110 SIPs grapples with the plain language of CAA section
302(k). Commenters believe Congress expressly requires both emission
standards and emission limitations to apply ``on a continuous basis,''
citing the definition at CAA 302(k), and that EPA is not entitled to
substitute its judgment for the plain intent of Congress. Commenters
state that EPA itself understands that the section 302(k) definition of
``emission limitation'' extends to section 110 SIPs and cite to an
action \106\ in which EPA references that definition to support the
position that an emission limitation is not required to be in numerical
form to qualify as a reasonably available control technology (RACT)
requirement in the Pennsylvania SIP. Commenters add that the relevant
statutory definition is not ``general enough'' to allow EPA to depart
from what Congress has specifically stated that the terms ``emission
limitation'' and ``emission standard'' mean and that the interpretation
EPA proposes has not been made available by the statute. Commenters
also state the requirement for ``continuous'' emission limitations
means that ``temporary, periodic, or limited systems of control'' do
not comply with the Act, citing Sierra Club, 551 F.3d at 1027 (quoting
H.R. Rep. No. 95-294, at 92 (1977), as reprinted in 1977 U.S.C.C.A.N.
1077, 1170).
---------------------------------------------------------------------------

    \106\ See 84 FR 20274, 20280 (May 9, 2019).
---------------------------------------------------------------------------

    Response 4: Commenters cite both to Mich. Dep't of Envtl. Quality
v. Browner \107\ and US Magnesium, LLC v. EPA \108\ and question why
the June 5, 2019, NPRM does not discuss the cases. At the outset,
Region 4 acknowledges the prior policy position cited by the
commenters, and for the reasons discussed thoroughly in the June 5,
2019, NPRM and this final action, Region 4 is adopting an alternative
interpretation with respect to the North Carolina SIP.
---------------------------------------------------------------------------

    \107\ See 230 F.3d 181 (6th Cir. 2000).
    \108\ See 690 F.3d 1157 (10th Cir. 2012).
---------------------------------------------------------------------------

    In MDEQ v. Browner, the Sixth Circuit Court of Appeals deferred to
EPA and found EPA Region 5's disapproval of certain Michigan SIP
provisions which exempted excess SSM emissions in specified
circumstances for the otherwise applicable regulations to be
reasonable.\109\ While the court did find that EPA's action was
reasonable in light of the Agency's existing SSM guidance, the decision
did not squarely speak to the legality of SSM exemptions in SIPs as a
general matter. The court was merely reviewing a challenge to a locally
applicable SIP action undertaken by one EPA regional office and found
that the regional office acted reasonably in disapproving certain
provisions.
---------------------------------------------------------------------------

    \109\ See 230 F.3d at 185.
---------------------------------------------------------------------------

    In US Magnesium, the petitioner challenged a SIP call issued to
Utah by EPA Region 8 due to an unavoidable breakdown rule included in
the Utah SIP. In its analysis, the Tenth Circuit Court of Appeals
determined that CAA 110(k)(5) is ambiguous, and then evaluated whether
the Region's disapproval action was reasonable.\110\ The court found it
allowable for an EPA regional office to make a determination regarding
the SIP's adequacy based on the Agency's ``understanding of the CAA.''
\111\ Similarly, this action is consistent with the understanding of
the CAA set forth herein. Further, the Tenth Circuit did not fault the
Agency for relying on a policy that had not gone through notice and
comment.\112\ In fact, the alternative policy being adopted by Region 4
and announced in this action went through a public comment process and
the Agency carefully considered all comments received. The Tenth
Circuit deferred to EPA's SIP call as being reasonable because it was
consistent with the Agency's interpretation of the

CAA at that time, as articulated in the document that accompanied that
action.\113\ While the court acknowledged that EPA's interpretation of
the CAA and application of that interpretation to the Utah SIP were
reasonable, like the Sixth Circuit, the Tenth Circuit did not squarely
rule on the legality of exemption provisions in SIPs. The commenter
also cites to the D.C. Circuit's 2008 Sierra Club decision, however
Region 4 has provided a thorough discussion of that decision in Section
III of the proposed action and this final action.
---------------------------------------------------------------------------

    \110\ See 690 F.3d at 1167.
    \111\ Id.
    \112\ Id.
    \113\ Id. at 1170.
---------------------------------------------------------------------------

    As discussed in Section III of the June 5, 2019, NPRM and of this
final action, Region 4 is adopting an alternative interpretation of the
interplay between CAA sections 302(k) and 110 which is supported by our
consideration of the generally protective terms and provisions of the
North Carolina SIP. As explained above in the response to Comment 2,
the U.S. Supreme Court has expressly provided that administrative
agencies may change an interpretation.\114\ Commenters' disagreement
with the interpretation does not preclude Region 4 from having
authority to change its policy if it is reasonable to do so.
---------------------------------------------------------------------------

    \114\ See Fox, 556 U.S. 502.
---------------------------------------------------------------------------

    As discussed in Section III of the June 5, 2019, NPRM and of this
final action, Region 4 disagrees with commenters' interpretation of the
scope of the Sierra Club decision and its application to SIP
provisions. The commenters read CAA section 302(k) too narrowly.
Further, the decision did not speak to the need for a SIP emission
limitation to apply on a ``continuous basis.'' Rather, the Court spoke
only regarding CAA section 112-compliant standards: ``When sections 112
and 302(k) are read together, then, Congress has required that there
must be continuous section 112-compliant standards. The general duty is
not a section 112-compliant standard. . . . Because the general duty is
the only standard that applies during SSM events--and accordingly no
section 112 standard governs these events--the SSM exemption violates
the CAA's requirement that some section 112 standard apply
continuously.'' \115\ Additionally, in Sierra Club, the D.C. Circuit
acknowledged that 302(k) did not necessarily require applying a single
standard continuously.\116\ Commenters' assertion that CAA 302(k)
mandates that SIP must contain emission limits composed of a single
standard that applies continuously is misplaced, impractically narrow,
and inconsistent with the plain words of the Sierra Club decision.
---------------------------------------------------------------------------

    \115\ See 551 F.3d at 1027-28 (emphasis added).
    \116\ See id. (interpreting CAA sections 302(k) and 112 together
to mean ``that some section 112 standard apply continuously'')
(emphasis added).
---------------------------------------------------------------------------

    Contrary to the commenter's allegation, Region 4 is not
``invent[ing]'' statutory authority. Rather, guided by the intent of
the provisions at issue, Region 4 has re-examined existing statutory
authority and considered the merits of an alternative interpretation.
As discussed in Section III of the June 5, 2019, NPRM and this final
rule preamble, the U.S. Supreme Court has instructed that states have
flexibility to ``adopt whatever mix of emission limitations it deems
best suited to its particular situation,'' and the alternative
interpretation adopted in this action reflects that flexibility.\117\
---------------------------------------------------------------------------

    \117\ Train v. Natural Res. Def. Council, Inc., 421 U.S. 60, 79
(1975).
---------------------------------------------------------------------------

    Legislative history cited by the commenters (and cited by the D.C.
Circuit) specifically says that provisions of section 106 of the
committee bill are intended ``to overcome the basic objections to
intermittent controls and other dispersion techniques which were
discussed in the background section.'' \118\ The comment
mischaracterizes relevant legislative history. Rather than indicating
that a single emission limitation must apply to a source continuously,
the legislative history indicates that the definition of emission
limitation be implemented through having some constant or continuous
emission reduction measures, but notably does not indicate an intent
for a single discrete measure.\119\
---------------------------------------------------------------------------

    \118\ H.R. Rep. No. 95-294, at 94 (1977).
    \119\ Id. at 92.
---------------------------------------------------------------------------

    Comments regarding the decision in U.S. Sugar Corp. v. EPA are
inapposite because the case was interpreting the Sierra Club decision
and both decisions deal with standards set pursuant to CAA section
112's strict requirements (and U.S. Sugar Corp. also addressed a CAA
section 129 rule which has a standard setting structure more similar to
CAA section 112 than section 110). As discussed in depth in section III
of the June 5, 2019, NPRM and of this final action, in this instance,
it is appropriate to distinguish those decisions from application to
SIPs under CAA section 110.
    Further, Region 4 disagrees that the definition in CAA section
302(k) is not general enough to have different meanings in different
contexts, as is explained in the discussion of the Duke Energy decision
in Section III of the June 5, 2019, NPRM and this final action.
    As explained in Section III.A., the automatic exemption provisions
in the North Carolina SIP do not relax an existing emission standard
during specified time periods. Rather, Region 4 interprets CAA section
110(a)(2)(A) to mean that a state may provide exemptions from emission
limits, during which times a source may be exempt from the emission
limit, because the SIP contains a set of emission limitations, control
means, or other means or techniques, which apply continuously and,
taken as a whole, meet the requirements of attaining and maintaining
the NAAQS.
    Region 4 disagrees that the alternative policy articulated in
Section III of the proposed action and this final action does not
engage with the terms in the definition of emission limitations in CAA
section 302(k). Rather, as explained in the NPRM and this document, the
alternative policy focuses on the purpose and context on the statutory
terms and provisions. Region 4 disagrees with commenters' contention
that the alternative interpretation adopted is contrary to the plain
language of CAA section 302(k). Depending upon context, the concept of
continuity may be applied differently in different situations. For
example, CAA section 402(7) defines the term ``continuous emission
monitoring system'' (CEMS) to mean equipment that provides a permanent
record of emissions and flow ``on a continuous basis.'' Yet CEMS
methods are required to provide such data at periodic intervals, not
for every moment of a unit's operation.\120\
---------------------------------------------------------------------------

    \120\ See 40 CFR 60.13(e)(1)-(2), 63.8(c)(4)(i)-(ii) (requiring
the minimum data collection frequency under the NSPS and NESHAP to
be once every 10 seconds for systems measuring opacity and once
every 15 minutes for systems measuring other types of emissions).
---------------------------------------------------------------------------

    Regarding rules 15A NCAC 2D .0535(c) and .0535(g), Region 4
disagrees with the commenters' assertion that a potential exemption for
SSM events means the emission limitations themselves are not
continuous. In fact, except for the exemption provided at 15A NCAC 2D
.1423(g) (as discussed elsewhere in this document), the SIP emission
limitations do apply at all times. Although the SIP provides, under 15A
NCAC 2D .0535(c) and .0535(g), that the Director may determine that a
particular instance of excess emissions is not a violation because it
was unavoidable, as demonstrated by the source, this does not mean that
the emission limit in question ceased to apply during the event.
Furthermore,

the fact that the NC DAQ Director might determine, after an instance of
excess emissions has occurred, that the event was unavoidable and thus
not a violation of a rule is unlikely to lessen a source's efforts to
comply with the standard in the first place. This argument is supported
by the facts that (1) 15A NCAC 2D .0502 requires all sources to be
provided with the ``maximum feasible control,'' which applies at all
times, including periods of startup and shutdown; (2) excess emissions
are generally emission limit violations, and facilities do not know in
advance whether any particular instance will be deemed by the State not
to be a violation, so the prudent course of action would be for sources
to try to avoid or limit any excess emission events; (3) 15A NCAC 2D
.0535(c) requires the Director, in making a malfunction determination,
to consider, among other things, whether all equipment has been
maintained and operated, to the maximum extent practicable, in a manner
consistent with good practice for minimizing emissions; and (4) 15A
NCAC .0535(g) directs facilities, during startup and shutdown, to
operate all equipment in a manner consistent with best practicable air
pollution control practices to minimize emissions and to demonstrate
that excess emissions were unavoidable when requested to do so by the
Director.
    Region 4 also disagrees with commenters that the interpretation
Region 4 proposed is not available under the statute. The House Report
language referenced by commenters comes from a section headed as ``2B.
Committee Proposal-Intermittent Controls and Tall Stacks.'' \121\ The
need for ``continuous controls'' is discussed in several places in the
report, but always in the context of intermittent controls, tall
stacks, and other dispersion enhancement techniques.\122\ Thus, it is
reasonable to interpret the phrase ``on a continuous basis'' in 302(k)
as intending to prevent intermittent controls,\123\ tall stacks, and
other dispersion techniques from being used as a means of emissions
control because those techniques do not actually reduce pollutant
emissions. As discussed above, the SSM exemption provisions in the
North Carolina SIP do not actually prevent the applicable limits from
applying continuously, and Region 4's interpretation is consistent with
the intent and language of CAA section 302(k).
---------------------------------------------------------------------------

    \121\ H.R. Rep. No. 95-294, at 91 (1977) (emphasis added).
    \122\ See, e.g., H.R. Rep. No. 95-294, at 6 (1977) (``Continuous
Controls.--The amendments would also affirm the decisions of four
U.S. court of appeals cases that the act requires continuous
emission reduction measures to be applied. Thus, intermittent
control measures (to be applied only in case of adverse weather
conditions), increasing stack heights, or other pollution dispersion
techniques would not be permitted as final compliance strategies.'')
and 190 (``Continuous Reduction--To make clear the committee's
intent that intermittent or supplemental control measures are not
appropriate technological systems for new sources . . ., the
committee adopted language clearly stating that continuous emission
reduction technology would be required to meet the requirements of
this section.'').
    \123\ ``Intermittent control'' is a concept in which emissions
are tailored to avoid violating ambient air quality standards under
meteorological conditions that inhibit pollutant dispersion but
without significantly reducing total pollutant emissions. Power
plants could accomplish this, at least in theory, by practices such
as shifting the electrical load to another power plant or using a
temporary supply of low sulfur fuel. See, e.g., EPA, National
Strategy for Control of Sulfur Oxides from Electric Power Plants at
11, (July 10, 1974), included in the docket for this rulemaking.
---------------------------------------------------------------------------

    The comment regarding the Pennsylvania RACT SIP is beyond the scope
of this action. Region 4's announcement of its alternative policy with
respect to SSM provisions in the North Carolina SIP is limited in scope
to North Carolina and does not impact or govern Region 3's evaluation
of SIPs within that Region's jurisdiction.
5. Comments That the Action is not an Appropriate Use of EPA's Regional
Consistency Process
    Comment 5: Commenters state that Region 4's process for the June 5,
2019, NPRM, including the memo for regional consistency and EPA's
accompanying FAQ document, do not support the ability to apply the
alternative policy to the North Carolina SIP or other Region 4 SIPs and
that EPA's action sets a dangerous precedent for approving exceptions
to national consistency. Commenters point out that EPA's national
action disapproved the same SIP provision that Region 4 proposed to
approve using regional guidance. Commenters state that the Region 4
memo request for concurrence and other materials in the rulemaking
docket do not contain any explanation for the basis for the alternative
interpretation and how such an alternative policy could apply in Region
4 while a contrary interpretation would apply to the rest of the
country. Commenters assert that EPA obviously wants to revise its
national policy, and should have to do so at the national level and
address the detailed explanations for the existing policy in so doing.
Commenters also assert that the Regional SIP action implicitly
establishes a new national policy on SSM in SIPs and, ``on the heels''
of the April 29, 2019, Region 6 proposed action in Texas, shows a clear
strategy by EPA to reverse a national policy by using Regional
decisions. Commenters state that it would be nearly impossible to
justify the Regional action overruling the national 2015 SSM SIP call
with respect to regional consistency and that Region 4's alternative
interpretation, combined with the alternative interpretation used in
the Region 6 NPRM, effectively deteriorates national consistency.
    Commenters state that the June 5, 2019, NPRM fails to meet the high
bar to justify alternative treatment from other Regions with respect to
SSM. One commenter asks how many states have made changes to SIPs in
response to the SSM SIP call, how many of those revised SIPs EPA has
approved, and what communications EPA has had with states about its
intent to act on pending SIP revisions or entertain further changes
from those states.
    Commenters state that Congress has granted EPA no authority to
authorize inconsistent interpretations of the Clean Air Act among
regions based on a signed concurrence memo from Headquarters.
Commenters state that the June 5, 2019, NPRM, and EPA Region 4's
pretense to be acting pursuant to EPA's ``consistency'' regulations, in
fact contradict 40 CFR 56.5(a) by proposing actions that are flatly
inconsistent with the Act and Agency policy. Commenters conclude that
Region 4 cannot use regulations addressing inconsistency with
``national policy'' to license violating the CAA. Commenters state that
the action would open the door to virtually any exception from national
policy on SSM and could therefore lead to increased emissions as well
as unnecessary legal proceedings when exceptions are challenged.
    Commenters state that EPA's proposed use of its regional
consistency regulations is both inconsistent with the plain meaning of
those regulations and not entitled to judicial deference under the
Auer-Kisor line of cases and that no deference would prevent a court
from applying the plain meaning of EPA regulations to overturn the
Agency's contrary interpretation. Commenters state that EPA
misinterprets Sec.  56.5(b) as allowing EPA Regions to take actions
that interpret the CAA in a manner inconsistent with national policy
when the Region seeks and obtains concurrence from the relevant EPA
Headquarters office. Commenters state that Region 4 cannot use
regulations addressing inconsistency with ``national policy'' to
license violating the Clean Air Act, contradicting and reversing a
national EPA rulemaking, and contravening the controlling D.C. Circuit
court decision. Commenters

state that Sec.  56.5(b) is not ambiguous for the purposes of this
action and does not permit EPA to concur with interpretations that
explicitly diverge from the Clean Air Act, a national EPA rulemaking,
and controlling court decision. Commenters state that Sec.  56.5(b)
does not allow regional offices to create inconsistency of their own
accord by approving a SIP that otherwise violates EPA's 2015 SSM SIP
Call. Commenters state that EPA may not simply issue a Sec.  56.5(b)
concurrence for any region that requests it--to contradict plain
statutory language, a national EPA rule, and controlling D.C. Circuit
court decision--as Regions 4 and 6 both have proposed. Commenters also
reference Sec.  56.3(b) as obligating EPA to ``correct[ ]
inconsistencies by standardizing'' the nationally-applicable policies
that must be employed by the EPA regional offices implementing and
enforcing the Act. Commenters conclude that EPA proposes a contrived
application of the regional consistency regulations it hopes will allow
it to undo the 2015 SSM SIP Call and circumvent both national
rulemaking to reverse the SIP Call and national review of this unlawful
action in the D.C. Circuit.
    Commenters add that, assuming for the sake of argument that the
June 5, 2019, NPRM could be approved under EPA's consistency
regulations, it would have to proceed under an additional provision, 40
CFR 56.5(c), which EPA has neither invoked nor fulfilled. Commenters
state that ``where proposed regulatory actions involve inconsistent
application of the requirements of the act, the Regional Offices shall
classify such actions as special actions,'' and ``shall follow'' the
Agency's guidelines for processing state implementation plans,
including EPA's guidance document ``State Implementation Plans--
Procedures for Approval/Disapproval Actions,'' OAQPS No. 1.2-005A or
revisions.\124\ Commenters add that compliance with EPA's consistency
regulations and guidance is required to give meaning and effect to
Congress's ``mandate to assure greater consistency among the Regional
Offices in implementing the Act.'' \125\
---------------------------------------------------------------------------

    \124\ See 40 CFR 56.5(c) (emphasis added).
    \125\ See 44 FR 13043, 13045 (March 9, 1979).
---------------------------------------------------------------------------

    Commenters also state that, despite an April 29, 2019, letter
captioned ``Regional Consistency Concurrence Request'' and a
``concurrence'' signed by the Director of Air Quality Planning and
Standards, there is no record evidence that EPA has, in fact, complied
with its consistency regulations and mandatory guidance documents in
proposing to exempt North Carolina and the rest of Region 4 from the
national SSM policy and, therefore, EPA cannot lawfully withdraw its
SSM SIP Call for North Carolina or approve the State's previously
submitted plan.
    Response 5: Comments challenging EPA's general authority to
authorize inconsistent interpretations of the Clean Air Act among
regions are outside the scope of this action. To the extent commenters
are raising concerns with the action taken by EPA Region 6 concerning
SSM SIP provisions in Texas, that is outside the scope of this action
and Region 4 provides no response.
    With respect to the concerns raised regarding this Region 4 action,
which is limited in scope to North Carolina, Region 4 did follow the
procedures outlined in the regional consistency regulations at 40 CFR
56.5(b), both at proposal as explained in the June 5, 2019, NPRM and
acknowledged by commenters, and at final. Specifically, before
proposing this action, the Region 4 Acting Regional Administrator at
the time, Mary S. Walker, sought and received EPA headquarters
concurrence to deviate from the national policy announced in the 2015
SSM SIP Call Action.\126\ Also, before finalizing of this action, the
Region 4 Regional Administrator sought and received EPA headquarters
concurrence to deviate from national policy in this final action.\127\
The commenters allege that Region 4 failed to follow the document
titled ``Revisions to State Implementation Plans--Procedures for
Approval/Disapproval Actions,'' OAQPS No. 1.2-005A, referenced in 40
CFR 56.5(c). That regulation requires the region to follow ``OAQPS No.
1.2-005A, or revision thereof.'' OAQPS No. 1.2-005A is a guideline from
1975; EPA has updated its procedures for approving and disapproving
SIPs many times since then. Region 4 did follow the most recent
iteration of EPA's internal SIP review process for ensuring national
consistency, which is EPA's 2018 SIP Consistency Issues Guide (included
in the docket for this rulemaking).
---------------------------------------------------------------------------

    \126\ See Document ID No. EPA-R04-OAR-2019-0303-0011, available
at www.regulations.gov.
    \127\ The concurrence request memorandum, signed March 19, 2020,
is included in the public docket for this action.
---------------------------------------------------------------------------

    The commenters also argue that Region 4 failed to provide
justification for deviating from the national policy outlined in the
2015 SSM SIP Action. Nothing in EPA's regional consistency regulations
or CAA section 301(a)(2) require a justification to underpin regional
deviation from national policy. All that is required by the applicable
regulations is that the region seek EPA headquarters concurrence for
the action it intends to take, when such action deviates from national
policy, and that has been done here. However, EPA's Office of Air and
Radiation did review a draft of this final action and determined that
the circumstances and rationale set forth in this action provide a
reasonable basis to concur on Region 4's deviation from the national
policy outlined in the 2015 SSM SIP Call Action.
    Region 4 disagrees with commenters' position that this action is
inconsistent with the regional consistency regulations at 40 CFR 56.5
and with the implication that the Agency has run afoul of 40 CFR 56.3.
The regulations in 40 CFR part 56 promote consistency but also clearly
contemplate that a regional office may seek to deviate from Agency
policy and provides a process and framework for doing so, which Region
4 has followed.\128\ Commenters assertion that Region 4's
interpretation of these regulations is not entitled to deference under
Auer or Kisor is similarly misplaced since Region 4 followed the
process set forth in the regulations. Commenters are reiterating their
concerns regarding the substance of Region 4's alternative policy for
the North Carolina SIP and couching it in a challenge to Region 4's
application of the regulatory provisions at 40 CFR 56.5.
---------------------------------------------------------------------------

    \128\ See, e.g., 80 FR 56418, 56420 n.4 (September 18, 2015), 82
FR 3234, 3239 n.10 (January 11, 2017), and 82 FR 24621, 24624 n.7
(May 30, 2017) (citing 40 CFR 56.5(b) consistency requirements in
proposing actions inconsistent with Agency interpretation).
---------------------------------------------------------------------------

    Region 4 acknowledges that the 2015 SSM SIP Call Action articulated
a different interpretation of the relevant statutory provisions.
However, as explained in Sections III and IV of the June 5, 2019, NPRM
and Section III of this final action, Region 4 has determined that an
alternative interpretation is warranted for the North Carolina SIP.
This action only outlines an alternative policy that applies to North
Carolina, based on the Agency's evaluation of air quality in North
Carolina and the North Carolina SIP. Region 4 is not, in this action,
establishing an alternative policy for any other states within its
jurisdiction. Application of an alternative policy in any other state
other than North Carolina would require a separate rulemaking action
subject to APA public comment requirements. To the extent the comments
discuss potential Agency actions beyond this action relating to the
North Carolina SIP, or precedent for

future Agency approaches to actions, such comments are out of scope for
this rulemaking.
    The comments that this action reverses a national policy or
establishes a new national policy overstates the scope of this action,
which only announces an alternative policy for analysis of the North
Carolina SIP and does not revise or otherwise alter the national policy
on SSM. Region 4 lacks authority to issue a policy beyond the states
included in the Region. Both the June 5, 2019, NPRM and this action
provide a detailed explanation for the basis for the alternative policy
and this action.
    In response to comments that refer to a controlling D.C. Circuit
court decision, Region 4 notes that there is no controlling D.C.
Circuit decision because, as discussed in the June 5, 2019, NPRM and in
Section III of this final action, Sierra Club does not, on its face,
apply to SIPs and actions taken under CAA section 110. Region 4
acknowledges that, if there were a directly controlling decision of the
U.S. Court of Appeals for the D.C. Circuit, Region 4 would be bound by
such a decision pursuant to 40 CFR 56.3(d).
    In response to the numerous questions posed by the commenters
regarding actions taken by other states with respect to SSM provisions
and actions taken by EPA with respect to any such state actions, the
present action is a state-specific action and any actions EPA has or
has not taken with respect to SIP submittals from other states in other
regions are not relevant to this action, and Region 4 provides no
response.

6. Comments That EPA Has Not Sufficiently Explained the Rationale
Behind the Action

    Comment 6: Commenters generally assert that EPA's explanation for
the proposed action is inadequate and conclusory and fails to meet
Agency standards for decision-making. The commenters claim that EPA has
not explained why the alternative interpretation of SSM policy is
warranted and that EPA's analysis regarding other provisions in the
North Carolina SIP, such as control requirements, maintenance,
limitations on the duration of SSM emissions, and general obligations
to comply with the NAAQS, only restates arguments that were discussed
and dismissed in the 2015 SSM SIP Call. Commenters state that EPA has
not supplied a reasoned analysis of why this change in course is
necessary, why it is especially necessary in Region 4 (and Region 6)
but nowhere else, or even why it might be good policy and that EPA is
therefore acting well outside the zone of deference State Farm and
later cases afford to agencies reversing course in this manner.
    Commenters state that EPA has not attempted to show that its prior
conclusions were flawed and that it is arbitrary and capricious for the
Agency to now rely on legal arguments it had exposed as faulty without
explaining why it was wrong to reject those arguments in the first
place. Commenters claim that EPA does not now disavow the policy
arguments it advanced in support of its plain-text reading of the CAA
in the 2015 SSM SIP Call and that EPA has advanced no policy rationale
beyond passing mentions of ``flexibility'' to address why allowing SIPs
to exempt SSM pollution would advance the goals of the CAA, much less
do so better than the status quo. Commenters state that ``[t]he Act's
purpose and policy is to protect air quality and the public welfare,
not to give states or polluters `flexibility' embodied, as here, by
exemptions that do not hold polluters directly accountable for excess
emissions.'' Commenters state that EPA's SSM SIP Call disapproval of
automatic exemptions rested, in part, on the correct conclusion that
even a single emission event could cause a NAAQS violation and that
EPA's reversal of that position is not accompanied by a reasoned
explanation for it.
    Commenters add that EPA's new vision of how the Act operates
ignores the history of failures that led to multiple amendments and the
plain statutory requirements of the Act as presently constructed,
stating that Congress's unwillingness to rely on the ``old ends-driven
approach that had proven unsuccessful'' is reflected in the specific
minimum requirements added throughout the 1990 CAA Amendments.
Commenters add that, while EPA is not precluded from adopting a
different approach to venue under the CAA, the Agency must at least
``display awareness that it is changing position'' and ``show that
there are good reasons for the new policy.'' \129\
---------------------------------------------------------------------------

    \129\ Fox, 556 U.S. at 515.
---------------------------------------------------------------------------

    Response 6: Region 4 disagrees that it has not adequately explained
its rationale for this action. Section III of the proposed action and
this final action, as well as Section IV of the June 5, 2019, NPRM
extensively explain the rationale for this action and why Region 4
believes it is warranted and is the appropriate approach in this
circumstance. Specifically, Section III of the June 5, 2019, NPRM and
this final rule preamble explain that the U.S. Supreme Court has
instructed that states have flexibility to ``adopt whatever mix of
emission limitations it deems best suited to its particular situation''
\130\ and the alternative interpretation adopted in this action
reflects that flexibility. Region 4 does not disagree with the
Commenters' assertion that the purpose of the CAA is to protect air
quality and public welfare.\131\ However, this action does not run
afoul of this purpose for numerous reasons, including that the North
Carolina SIP contains overlapping protective provisions and, as
discussed further in response to Comment 8, the fact that air quality
in North Carolina has continued to improve over the years even though
exemption provisions have been included in the SIP. No areas of North
Carolina are currently designated nonattainment for any NAAQS.\132\
---------------------------------------------------------------------------

    \130\ Train, 421 U.S. at 79.
    \131\ See 42 U.S.C. 7401(b)(1).
    \132\ See https://www3.epa.gov/airquality/greenbook/ancl3.html.
---------------------------------------------------------------------------

    EPA has a statutory obligation to approve SIPs that meet all
applicable CAA requirements. Region 4 has evaluated the North Carolina
SIP in light of the alternative SSM policy interpretation set forth in
the proposed and final actions--a policy which as explained above is
consistent with the CAA--and has determined that the submitted SIP
revision meets all applicable CAA requirements. Due, in part, to Region
4's adoption of an alternative policy for the North Carolina SIP,
Region 4 has approved the June 5, 2017, SIP revision before EPA.
    Commenters challenge Region 4's deviation from the national policy
without explaining why that national policy is wrong, but commenters
fail to recognize that no such explanation is required. The appropriate
standard for evaluating an agency change in position was set forth in
Motor Vehicle Mfrs. Ass'n of United States, Inc. v. State Farm Mut.
Auto. Ins. Co.\133\ and clarified in FCC v. Fox Television Stations,
Inc.\134\ The Fox Court explained that a change in position does not
require a heightened showing and that an agency ``need not demonstrate
to a court's satisfaction that the reasons for the new policy are
better than the reasons for the old one.'' \135\ Rather, ``it suffices
that the new policy is permissible under the statute, that there are
good reasons for it, and that the agency believes it to be better,
which the conscious change of course adequately indicates.'' \136\
---------------------------------------------------------------------------

    \133\ See 463 U.S. 29 (1983).
    \134\ See 556 U.S. 502 (2009).
    \135\ Id. at 515 (emphasis original).
    \136\ Id. (emphasis original).

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

    Region 4's June 5, 2019, NPRM acknowledged this change in position
by explaining the Agency's historical approach with respect to SSM
exemption provisions in SIPs. As articulated in the June 5, 2019, NPRM
and reiterated and expanded on in this final action, Region 4 explains
how this alternative interpretation is consistent with the statutory
text. North Carolina's exemption provisions are reasonably bounded and
provide backstop protections of instructing sources to limit excess
emissions and maintain pollution control equipment in good working
order, among other things. For example, as discussed in more detail in
the June 5, 2019, NPRM, the exemption at 15A NCAC 2D .0535(g) requires
that owners or operators use best available control practices when
operating equipment to minimize emissions during startup and shutdown
periods, and the exemption provided at 15A NCAC 2D .0535(c) outlines
seven criteria that provide additional protections of the NAAQS during
a malfunction by requiring consideration of, among other things,
whether sources have minimized emissions and have limited the extent of
emissions which could occur to the greatest extent practicable and by
prohibiting the Director from excusing excess emissions from a source
due to malfunctions for more than 15 percent of a source's operating
time.
    Moreover, North Carolina's SIP includes numerous additional
provisions protecting against NAAQS exceedances or otherwise causing
excess emissions. As discussed in more detail in the proposal, 15A NCAC
2D .0502 requires ``maximum feasible control'' on all sources at all
times, including periods of startup and shutdown; 15A NCAC 2D .0501(e)
directs all sources to operate in a manner that does not cause any
ambient air quality standard to be exceeded at any point beyond the
premises on which the source is located; 15A NCAC 2D .0535(d) requires
utility boilers (and any source with a history of excess emissions, as
determined by the Director) to have a malfunction abatement plan
approved by the Director and identifies the minimum requirements for
such a plan; 15A NCAC 2D .0510(a), 15A NCAC 2D .0511(a), and 15A NCAC
2D .0512 prohibit emissions from sand, gravel, or crushed stone
operations, lightweight aggregate operations and wood products
finishing plants from causing exceedance of ambient air quality
standards beyond facility property lines; 15A NCAC 2D .0521(g), for
sources that operate COMS, prohibits any exempted excess opacity
emissions from causing or contributing to a violation of any emission
state or Federal standard; and the North Carolina Clean Smokestacks Act
(NCCSA), codified at 40 CFR 52.1781(h), limits NOX and
SO2 emissions from coal-fired power plants to utility-wide
caps designed as part of North Carolina's comprehensive plan for
improving air quality in the State. Region 4 also notes that 15A NCAC
2D .0535 (Excess Emissions Reporting and Malfunctions), including the
exemption provisions at 2D .0535(c) and .0535(g), does not apply where
sources are subject to Federal standards.\137\
---------------------------------------------------------------------------

    \137\ See 15A NCAC 2D .0535(b), which provides that 15A NCAC 2D
.0535 does not apply to sources subject to North Carolina
regulations adopting EPA's NSPS or NESHAP at 40 CFR parts 60, 61 and
63, except where such sources are subject to a SIP provision that is
more stringent than Federal requirements.
---------------------------------------------------------------------------

    Finally, as previously mentioned, North Carolina currently does not
have any areas designated non-attainment under any NAAQS. Together with
the goal of providing states with adequate flexibility to address air
quality issues, Region 4 has good reason to change the policy position
for North Carolina. Region 4 believes this is the better course of
action in this case and is thus pursuing this change in policy for
North Carolina.

7. Comments That the Notice of Proposed Rulemaking Fails to Demonstrate
Compliance With CAA Section 110(l)

    Comment 7: Commenters state that, in the event of a SIP element's
substantial inadequacy, CAA section 110(l) provides that EPA must not
approve a SIP containing that element. Commenters state that EPA has
failed to show compliance with CAA 110(l) and that the June 5, 2019,
NPRM failed to address or even mention it. Commenters also state that
EPA is wrong to point to ``redundancies'' in the North Carolina SIP to
justify its proposed approach because overlapping protections are
deliberately implemented to ensure air quality and public welfare are
robustly protected, not to provide wiggle room for later deregulatory
actions.
    Commenters also state that demonstrating compliance with the
national standards is not the sole measure for approval of a SIP
revision. SIPs in nonattainment areas must also ``meet the applicable
requirements of part D.'' In addition, commenters note that CAA
section[thinsp]107(d)(3)(E) provides that EPA cannot redesignate a
nonattainment area as an attainment area unless it finds not only that
the area has attained the NAAQS, but also that ``the State containing
such area has met all [the] requirements applicable to the area under
section 7410 of this title and part D of this subchapter.''
    Response 7: Region 4 disagrees that it failed to address or to show
compliance with CAA section 110(l), which provides that ``[t]he
Administrator shall not approve a revision of a plan if the revision
would interfere with an applicable requirement concerning attainment
and reasonable further progress . . . or any other applicable
requirement of this chapter.'' \138\ The decision to withdraw the SIP
Call for the exemption provisions at 15A NCAC 2D .0535(c) and 15A NCAC
2D .0535(g) does not implicate CAA section 110(l) because it does not
constitute a revision to an implementation plan; the provisions were
approved into the North Carolina SIP in 1986 \139\ and 1997,\140\ and
have been in the North Carolina SIP ever since. Additionally, although
Region 4 did not directly cite CAA section 110(l) in the June 5, 2019,
NPRM, we proposed to find that the exemption included in the revised
SIP provision, ``when considered in conjunction with other elements in
the North Carolina SIP, [is] sufficient to provide adequate protection
of the NAAQS'' and to determine that the SIP changes ``are consistent
with CAA requirements.'' \141\ As explained in Section IV of the June
5, 2019, NPRM, that proposed determination was explicitly conditioned
upon adoption of, as well as based upon, the alternative policy
outlined in Section III of the proposed action. The alternative policy
was supported by a number of considerations explained in the proposal,
including that the North Carolina SIP, as a whole, is protective of the
NAAQS. Furthermore, the exemption included in the revised SIP provision
is already in the current North Carolina SIP, and no changes are being
made to that exemption through this action.
---------------------------------------------------------------------------

    \138\ See 42 U.S.C. 7410(l).
    \139\ EPA approved 15A NCAC 2D .0535(c) into the North Carolina
SIP on September 9, 1986 (51 FR 32073).
    \140\ EPA approved 15A NCAC 2D .0535(g) into the North Carolina
SIP on August 1, 1997 (62 FR 41277).
    \141\ See 84 FR at 26040.
---------------------------------------------------------------------------

    The comment that EPA cannot redesignate a nonattainment area under
CAA section 107(d)(3)(E) is not within scope for this rulemaking
because EPA is not redesignating any areas previously classified as
nonattainment areas in this action; in addition, we note that North
Carolina does not currently

have any nonattainment areas for any NAAQS.

8. Comments That Region 4 has not Shown That the North Carolina SIP is
Protective of the NAAQS

    Comment 8: Commenters state that if EPA believes each SIP should be
evaluated to determine whether automatic or discretionary SSM
exemptions are compatible with the NAAQS, the risk analysis must be
more direct. EPA must acknowledge the uncertainty around NAAQS
protection given how discretion with subjective terms might be applied.
Commenters claim that EPA should have done an analysis of the sources
in North Carolina and how these exemptions would not impact the State's
ability to attain and maintain the NAAQS and that EPA in fact tried to
obscure an accurate characterization of the risk in the June 5, 2019,
NPRM. Commenters assert that EPA did not provide adequate legal or
technical justification that the SIP is adequate to protect public
health or that it is consistent with the CAA as interpreted in EPA's
national rulemakings (such as the 2015 SSM SIP Call). Commenters state
that the June 5, 2019, NPRM and accompanying supporting documents fail
to provide sufficient analysis on how the North Carolina SIP, even with
the SSM exemptions, ensures protection of the NAAQS or increment or any
other substantive requirement. Commenters also state that EPA's
proposal is not clear on whether there is little risk or no risk that
the NAAQS and Prevention of Significant Deterioration (PSD) increments
will be exceeded in North Carolina as a result of the SIP approval and
withdrawal of the SSM SIP Call.
    Commenters also disagree that limiting malfunctions to 15 percent
of a source's operating time, as required by 15A NCAC 2D .0535(f), will
reasonably minimize the risk that excess emissions during these periods
will contribute to NAAQS exceedances or violations. In addition,
regarding an example SIP provision highlighted in the June 5, 2019,
NPRM, commenters assert that annual emissions budgets for electricity
generating units (EGUs) in North Carolina are insufficient constraints
for short-term periods of exempted excess emissions, which could cause
NAAQS exceedances and contribute to violations.
    Response 8: The commenters' statements imply that the discretionary
criteria of the North Carolina SSM provisions do not meet the
requirements of the CAA or protect against violations of the NAAQS. To
the extent that commenters may be suggesting that this action must be
supported by a risk analysis, Region 4 notes that risk analysis is a
requirement of CAA section 112, not CAA section 110. For example, CAA
section 112(o) requires the EPA Administrator to conduct a review of
risk assessment methodology used to determine the carcinogenic risk
associated with exposure to hazardous air pollutants. CAA section
112(f) requires EPA to investigate and report on the risks to public
health from sources of hazardous air pollutants that remain, or are
likely to remain, after application of the emission standards
promulgated by EPA under CAA section 112(d). CAA section 110 requires
states to adopt, and EPA to approve, plans for achieving and
maintaining compliance with the NAAQS, but ``risk analysis'' is not a
required element for SIP submissions (under section 110(A)(2) or any
other SIP-related sections). This highlights another difference in
purpose and approach between CAA section 110 and CAA section 112.
    Regarding the Commenter's concern about uncertainty around NAAQS
protection given how discretion with subjective terms might be applied,
Region 4 notes that a SIP does not provide complete certainty around
NAAQS protection, regardless of whether it contains SSM exemptions. For
this reason, the Act requires that remedial measures be taken in any
area designated as nonattainment with respect to a NAAQS (CAA section
172(b)) and, if such area fails to make reasonable further progress or
to attain the NAAQS by the date required, the Act requires that
specific contingency measures will take effect automatically (CAA
section 172(c)(9)). Further, given the limitations on the NC DAQ
Director's discretion, as discussed in Section III of this final
action, and the State's responsibility to implement a program that
achieves and maintains compliance with the NAAQS, Region 4 believes the
Director would exercise that discretion in a manner that supports
protection of air quality.
    Region 4 assumes the commenter's reference to North Carolina SIP
``provisions that apply to EGUs that are more protective than the
provisions applying to other types of sources'' is to the NCCSA, a
State law which, as noted above and in the proposal, imposes limits on
NOX and SO2 emissions from public utilities
operating coal-fired power plants that may not be met by purchasing
emissions credits.\142\ Those NOX and SO2 limits
were incorporated into the North Carolina SIP \143\ and resulted in
permanent emission reductions that helped nonattainment areas in the
State achieve attainment of the 1997 Annual PM2.5
NAAQS.\144\ Region 4 did not suggest in the June 5, 2019, NPRM that the
NCCSA limits are, per se, totally protective of the short-term NAAQS,
but rather that they serve as some of the several overlapping
requirements that, together, are sufficient to ensure attainment and
maintenance of the NAAQS.\145\
---------------------------------------------------------------------------

    \142\ See 84 FR at 26038.
    \143\ See 76 FR 59250 (September 26, 2011).
    \144\ See 76 FR 58210, 58217 (September 20, 2011); 76 FR 59345,
59352 (September 26, 2011).
    \145\ See 84 FR at 26037-38.
---------------------------------------------------------------------------

    As Region 4 has thoroughly explained above in section 6 of the
response to comments, the alternative policy being adopted for North
Carolina conforms with FCC v. Fox Television Stations, Inc., as the
policy ``is permissible under the statute, . . . there are good reasons
for it, and . . . the agency believes it to be better, which the
conscious change of course adequately indicates.'' \146\ Based on
Region 4's analysis of the North Carolina SIP, and for the reasons
articulated in the June 5, 2019, NPRM and this final action, Region 4
is deviating from the policy outlined in the 2015 SSM SIP Action in
this action limited to North Carolina.
---------------------------------------------------------------------------

    \146\ See 556 U.S. 502, 515 (2009) (emphasis original).
---------------------------------------------------------------------------

    Region 4 believes that the withdrawal of the SSM SIP call will not
affect North Carolina's ability to attain or maintain the NAAQS, nor
will it affect North Carolina's PSD increments. This is because the SSM
exemption provisions of the SIP, 15A NCAC 2D .0535(c) and 15A NCAC 2D
.0535(g), have been in the approved SIP for many years and are not
being revised by this action and because, as discussed in response to
Comment 10 below, any excess emissions from large internal combustion
engines exempted by 15A NCAC 2D .1423(g) are expected to be a small
fraction of those units' overall emissions. In fact, even with the SSM
exemptions included in the North Carolina SIP, the State currently has
no areas designated nonattainment for any NAAQS.\147\ Moreover,
historic ambient air quality monitoring data collected in the State
show decreasing overall trends in NAAQS pollutant concentrations over
time, as demonstrated in the graphics included in the docket for this
rulemaking.\148\
---------------------------------------------------------------------------

    \147\ See https://www3.epa.gov/airquality/greenbook/ancl3.html.
    \148\ See document titled ``NC NAAQS Trends Figures'' prepared
by Region 4 and included in the docket for this rulemaking.

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

    Likewise, Region 4 does not have evidence indicating PSD increments
\149\ will be exceeded in North Carolina as a result of the withdrawal
of the SIP Call. PSD increments are protected in the State in the same
way that the NAAQS are. Further, Region 4 notes that in 2002 EPA
revised the PSD program and clarified that for purposes of determining
emissions from an emissions unit, ``a unit is considered operational
not only during periods of normal operation, but also during periods of
startup, shutdown, maintenance, and malfunction, even if compliance
with a non-PAL emission limitation is excused during these latter
periods.'' \150\ The rulemaking added new provisions that specifically
require consideration of emissions during SSM events in PSD
construction projects.\151\
---------------------------------------------------------------------------

    \149\ PSD is the federally required pre-construction permitting
program that applies to new major sources or major modifications at
existing sources for pollutants in areas that are not designated as
nonattainment with the NAAQS. The PSD increment is the amount that
the ambient pollutant concentration is allowed to increase in an
area to allow for economic growth but also prevent the air quality
from deteriorating to the level set by the NAAQS.
    \150\ See 67 FR 80186, 80213 (December 31, 2002).
    \151\ For example, the definitions of ``baseline actual
emissions'' (the average annual rate that a unit actually emitted a
relevant pollutant in recent years) and ``projected actual
emissions'' (the maximum annual rate at which an existing emission
unit is projected to emit the relevant pollutant after modification)
require the inclusion of ``emissions associated with startups,
shutdowns, and malfunctions.'' See 40 CFR 51.166(b)(40)(ii)(b),
(b)(47)(i)(a), and (b)(47)(ii)(a).
---------------------------------------------------------------------------

    Region 4 disagrees with the commenter's criticism of the Agency's
recognition of the restriction on the amount of time a source may be
deemed to have experienced a malfunction and believes that limiting
malfunctions to 15 percent of a source's operating time per year
establishes a reasonable constraint on the Director's exercise of
discretion pursuant to 15A NCAC 2D .0535. Further, evidence that North
Carolina is not currently designated nonattainment for any NAAQS
indicates that the SIP, as a whole, is ensuring attainment and
maintenance of the NAAQS and that the SSM exemption provisions are
appropriately bounded and are not a source of nonattainment issues in
the State.

9. Comments That the Provisions Relied Upon are not Practicably or
Legally Enforceable

    Comment 9: Commenters state that in the pending D.C. Circuit
litigation in Walter Coke Inc. v. EPA, No. 15-1166, Petitioners have
argued that exempting SSM events from numerical limits is appropriate
and lawful because ``general duty'' SIP provisions provide continuous
control during all modes of source operation. Commenters argue that not
only do such generic provisions fail to meet the level of control
required by the applicable stringency requirements, such as reasonably
available control technology in nonattainment areas, best available
control technology for certain sources in attainment areas, and best
available retrofit technology for sources impacting regional haze, but
also that general duty provisions are not legally or practically
enforceable, as required by the Act. Commenters state that EPA is also
wrong to claim that SIP provisions are approvable so long as they do
not preclude attainment of the NAAQS and a ``general duty'' provision
remains in effect.
    Commenters state that, as part of the enforcement scheme, the CAA
provides for citizens to have easy access to courts to improve the
efficacy of the protections established under it, but that Congress
carefully cabined citizen suits to violations of clear standards,
requiring plaintiffs to allege a violation of ``a specific strategy or
commitment in the SIP.'' Commenters argue that since general duty
provisions are not quantifiable or objective, they run afoul of these
limitations and thus conflict with congressional intent that citizens
be able to enforce emission limitations contained in SIPs. Commenters
state that because courts refuse to enforce unquantifiable CAA
standards, attempts to enforce general duty and other work practice
provisions in SIPs have been unsuccessful, thus concluding that vague
and unenforceable general duty provisions are no substitute for
continuous emission limitations that apply during all phases of
operation.
    Commenters state that Sierra Club broadly rejects EPA's proposal
that SSM exemptions are allowable because a continuous ``general duty''
would satisfy section 302(k)'s continuity requirement that some section
112 standard apply continuously. Commenters also state that Sierra
Club's holding relied on a determination that the general duty
provision (or other general guarantees) may not satisfy 302(k)'s
continuity requirement, which is the argument EPA made in proposal.
    Response 9: Commenters' references to the Sierra Club court's
interpretation of general duty provisions is inapposite. As discussed
in Section III of both the proposal and this final action, the court in
Sierra Club was explicitly evaluating whether a general duty provision
met the strict framework of CAA section 112. As quoted by the
commenters, the court specifically stated that ``[t]he general duty is
not a section 112-compliant standard.'' \152\ As discussed in the
proposal and above, on its face, the Sierra Club decision is limited to
CAA section 112 and does not extend to CAA section 110. Therefore,
commenters' citation to the Sierra Club decision with respect to
general duty provisions does not govern this action taken pursuant to
CAA section 110.
---------------------------------------------------------------------------

    \152\ Sierra Club v. EPA, 551 F.3d 1019, 1027 (D.C. Cir. 2008).
---------------------------------------------------------------------------

    Region 4 disagrees with commenters' contention that general duty
provisions are, writ large, not legally or practicably enforceable.
Region 4 acknowledges that in some instances general duty provisions
may present unique enforcement challenges; that alone does not mandate
a conclusion that such provisions are wholesale unenforceable. The
interpretation advanced in this document does not preclude citizens or
the United States from enforcing SIP provisions, as appropriate. Region
4 disagrees with commenters' narrow characterization of its position
being that a SIP provision is approvable provided a general duty
provision serves as a backstop. This interpretation oversimplifies the
alternative policy. As articulated in Sections III and IV of the
proposal and Section III of this final action, the alternative policy
is predicated on a holistic evaluation of the North Carolina SIP. While
the NPRM identifies numerous general duty provisions that serve as
backstops ensuring NAAQS attainment and maintenance, those are not
necessarily the only considerations contributing to our determination
that it is appropriate to withdraw the SIP call previously issued to
North Carolina.
    Contrary to commenters' assertion, Region 4 does not advocate
general duty provisions ``substituting'' for continuous emission
limitations. Rather, the alternative policy provides that the North
Carolina SIP may contain SSM exemption provisions because the SIP, as a
whole, is protective of the NAAQS. One component of protection is that
the SIP includes general duty provisions. However, as discussed in the
proposal and above, the analysis does not end there. North Carolina's
SIP includes numerous additional provisions protecting against NAAQS
exceedances or otherwise causing excess emissions.

10. Comments on Environmental and Health Impacts

    Comment 10: Commenters state that reinstating North Carolina's
automatic exemptions for SSM emission events would be a ``free pass to
pollute with impunity.'' Commenters state that so long as excess
emissions from SSM

events escape regulation, polluters have little incentive to invest in
fixing known plant issues or improving the equipment necessary to avoid
breakdowns and reduce the need for ``unscheduled maintenance'' because
they know they will not face consequences for illegal pollution
released during these events, which is a problem because emission
events and pollution released during ``unauthorized maintenance'' is a
major threat to public health and the environment. Commenters also
state that allowing excess emissions from SSM events to escape
regulation would undermine North Carolina's obligations to protect and
maintain safe air quality, both within the state and for downwind
neighbors.
    Commenters state that approval of the North Carolina SIP revision
would ``sanction emissions of potentially substantial amounts of
unhealthy air pollution'' which would be emitted during periods of SSM
in amounts that cannot be determined in advance and therefore cannot
assure protection of the NAAQS. Commenters claim that SSM events
release ``huge amounts'' of pollution that can cause exceedances and
violations of the NAAQS and cite to an example in which ``one known
event released 165,000 pounds of sulfur dioxide.''
    Commenters claim that reviving SSM exemptions in North Carolina and
in Region 4 would frustrate the attainment efforts of nearby states and
regions along the east coast, particularly in the ozone and
SO2 nonattainment zones around Washington, DC, and Baltimore
and surrounding counties in Virginia and Maryland. Commenters also
state that Sullivan County, Tennessee, near the North Carolina border,
is currently also a nonattainment area for SO2 and that
North Carolina itself has consistently faced pollution from neighboring
states, and that Mecklenburg County, North Carolina, is close to
violation of the 2015 ozone standard.
    Commenters state that EPA's approval of attainment and maintenance
plans for certain NAAQS did not consider excess emissions that may
occur and that, for some pollutants, approval of the plan relied on a
monitoring network that did not cover the land area of the state.
Commenters also state that, because of the limited air quality
monitoring network, violations of the NAAQS may escape official notice,
but the harmful effects of SSM events nonetheless burden the
neighboring communities.
    Commenters note that a study, provided as an attachment to the
comments,\153\ provides information about the frequency and magnitude
of excess emissions in the State of Texas and claim that SSM emissions
can undermine CAA protections if state rules exclude them from
regulation. Commenters state that neither EPA nor North Carolina has
done any analysis to evaluate the extent of excess emissions that could
be authorized by the SIP revision. Commenters state that exempting SSM
events from regulation threatens not only maintenance of those
standards (as discussed above) but also human lives by allowing high
concentrations of deadly fine particulate matter to form. Commenters
also state that the Act's requirement for continuously enforceable
emission limitations is vitally important for protecting public health.
In support of this statement commenters quote a 2016 EPA brief in
litigation regarding the 2015 SSM SIP Call,\154\ which quotes the 2015
action,\155\ which quotes the House Report on the 1977 CAA Amendments
as stating, ``Without an enforceable emission limitation which will be
complied with at all times, there can be no assurance that ambient
standards will be attained and maintained.'' \156\
---------------------------------------------------------------------------

    \153\ The study, titled ``The health consequences of weak
regulation: Evidence from excess emissions in Texas,'' appears to be
an unpublished document downloaded from the internet at https://www.ssrn.com/index.cfm/en/.
    \154\ Walter Coke Inc. v. EPA, No. 15-1166 (and consolidated
cases) (D.C. Cir.).
    \155\ See 80 FR at 33901.
    \156\ H.R. Rep. No. 95-294, at 92 (1977).
---------------------------------------------------------------------------

    Commenters also note that in EPA's 2015 action, it acknowledged it
was particularly concerned about the potential for serious adverse
consequences for public health in the interim period during which
states, EPA and sources were to make adjustments to rectify deficient
SIP provisions and take steps to improve source compliance. Commenters
state that EPA has not explained in this rulemaking why those concerns
are no longer justified or relevant to this action and that EPA has not
addressed or even mentioned the health effects of the action in
qualitative or quantitative terms.
    Response 10: Region 4 clarifies that no provisions are being
reinstated into the North Carolina SIP. In this action, Region 4 is
approving changes to existing rule 15A NCAC 2D .1423, as requested by
North Carolina. The State's provisions that were subject to the SSM SIP
Call, 15A NCAC 2D .0535(c) and .0535(g), were approved by EPA on
September 9, 1986,\157\ and on August 1, 1997,\158\ respectively, and
have never been removed from the SIP. Withdrawal of the SSM SIP Call
for North Carolina only means that the State is not required to provide
a SIP revision responsive to the SIP Call for 15A NCAC 2D .0535(c) and
.0535(g).
---------------------------------------------------------------------------

    \157\ See 51 FR 32073.
    \158\ See 62 FR 41277.
---------------------------------------------------------------------------

    Region 4 disagrees with the comment that these rules provide
sources throughout Region 4 a ``free pass to pollute with impunity.''
As an initial matter, this action is limited in scope to the North
Carolina SIP and does not cover sources throughout Region 4.
Additionally, as discussed in the June 5, 2019, NPRM, 15A NCAC 2D
.0535(c) and .0535(g) themselves (and other provisions of the SIP)
direct sources, to the extent practicable, to minimize emissions at all
times, including periods of SSM. These rules also provide that only
excess emissions that were unavoidable by the source may be considered
not to be violations of applicable rules. Under 15A NCAC 2D .0535(c),
excess emissions that occur at any time other than a period of startup
or shutdown are violations of the applicable SIP limit unless the owner
or operator demonstrates, to the degree required by the Director's
judgment, that the emissions are the result of a malfunction (i.e.,
unavoidable failure of air pollution control equipment, process
equipment, or process, as defined at 15A NCAC 2D .0535(a)(2)). To
determine whether excess emissions are the result of a malfunction, the
Director shall consider, among other factors listed in the rule,
whether the air cleaning device, process equipment, or process have
been maintained and operated, to the maximum extent practicable, in a
manner consistent with good practice for minimizing emissions. Thus, a
determination by the Director that these criteria have not been met
would mean that excess emissions are not the result of a malfunction
and, therefore, are a violation of the appropriate rule.
    Likewise, 15A NCAC 2D .0535(g) requires that excess emissions that
occur during periods of startup and shutdown are violations of the
appropriate rule if the owner or operator cannot demonstrate that the
emissions were unavoidable, when requested by the Director to do so.
Any determination by the Director that the owner or operator has not,
to the extent practicable, operated the source and any associated air
pollution control equipment or monitoring equipment in a manner
consistent with best practicable air pollution control practices to
minimize emissions during

startup or shutdown would mean that any excess emissions are a
violation of the appropriate rule.
    Commenters' statements are unclear as to what is meant by the terms
``unscheduled maintenance'' and ``unauthorized maintenance.''
``Maintenance'' may be defined as the work of keeping something in a
suitable condition \159\ and therefore consists of normal, periodic
equipment upkeep activities that help to prevent equipment failures.
Region 4 understands the commenters' intent to be that if SSM events
are unregulated, sources lack incentive to maintain their equipment or
improve emission controls. The comment seems to presume, without
evidence, that source owners and operators conduct their processes and
operate their facilities with reckless disregard for the environment
and without regard for other SIP provisions requiring control of
emissions and protection of the NAAQS, as discussed above. Region 4 is
not aware of reasons to suspect this to be the case. Region 4 disagrees
with the commenters' conclusion that sources will not face consequences
for illegal pollution released during SSM events. As described above,
SSM events that result from a failure to address known plant issues or
conduct routine maintenance would likely not meet the criteria outlined
for the Director's consideration regarding when excess emissions are
not considered a violation.
---------------------------------------------------------------------------

    \159\ See Webster's II New Riverside University Dictionary 717
(Anne H. Soukhanov, Senior Editor, The Riverside Publishing Company,
1984) (defining ``maintenance'').
---------------------------------------------------------------------------

    Region 4 also notes that the action approving 15A NCAC 2D .0535(c)
into the North Carolina SIP specifically stated that EPA retains
authority to pursue enforcement of any particular case: ``it should be
noted that EPA is not approving in advance any determination made by
the State under paragraph (c) of the rule, that a source's excess
emissions during a malfunction were avoidable and excusable, but rather
is approving the procedures and criteria set out in paragraph (c).
Thus, EPA retains its authority to independently determine whether an
enforcement action is appropriate in any particular case.'' \160\
Moreover, North Carolina has already stated its position that
``[n]othing in the existing SIP provisions prohibits or restricts in
any way the ability of the EPA and/or a citizen to file an action in
federal court seeking enforcement of the SIP provisions.'' \161\
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    \160\ See 51 FR 32073, 32074 (September 9, 1986.)
    \161\ Letter from Sheila C. Holman, Director, NC DAQ, to EPA,
May 13, 2013, page 3, Docket ID No. EPA-HQ-OAR-2012-0322-0619,
available at www.regulations.gov.
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    As described in the preceding paragraphs, Region 4 disagrees that
15A NCAC 2D .0535(c) and .0535(g) allow pollutant emissions to escape
regulation and that the State's implementation plan lacks regulatory
incentive for sources to maintain their equipment and upgrade emission
controls when possible. Further, regular source maintenance activities
are essential to avoiding excess emision events and are incentivized by
the regulatory requirements to submit excess emission reports under 15A
NCAC 2D .0535(f), which provides that all instances of excess emissions
which last for more than four hours, regardless of whether due to
malfunction or any other abnormal condition, must be communicated to
the Director or designee within 24 hours of the occurrence. The SIP
does not automatically require such reports for excess emission events
lasting less than four hours; however, 15A NCAC 2D .0605 requires that
all monitoring records be retained by the owner or operator and made
available for inspection for a period of two years. In addition, all
sources subject to the title V permitting program, including all major
sources of pollutants subject to regulation, must submit to the State
semiannual monitoring reports and annual compliance certifications that
clearly identify all instances of deviations from permit
requirements.\162\
---------------------------------------------------------------------------

    \162\ See 15A NCAC 2Q .0508(f), .0508(n); 40 CFR
70.6(a)(3)(iii), (c)(5)(iii)(C).
---------------------------------------------------------------------------

    The SIP revision being approved through this action is limited to
15A NCAC 2D .1423, the State's rule regulating emissions of
NOX from ``large internal combustion engines.'' North
Carolina's June 5, 2017, SIP revision includes several changes to this
rule. Among the provisions being revised is 15A NCAC.1423(d)(1),
``Compliance determination and monitoring.'' North Carolina modified
15A NCAC.1423(d)(1) to ensure that CEMS data used for determination of
compliance with this rule meet applicable SIP requirements as well as
Federal requirements. Section 2D .1423(d)(1) of the State's current
federally-approved SIP provides that the owner or operator of a subject
internal combustion engine shall determine compliance using ``a [CEMS]
which meets the applicable requirements of Appendices B and F of 40 CFR
part 60, excluding data obtained during periods specified in Paragraph
(g) of this Rule.'' \163\ Paragraph (g) of Section 2D .1423, which is
already included in the current federally approved SIP, provides that
the emission standards therein do not apply during periods of ``(1)
start-up and shut-down periods and periods of malfunction, not to
exceed 36 consecutive hours; (2) regularly scheduled maintenance
activities.'' As proposed in Section IV of the NPRM, Region 4 finds
that the provisions of 15A NCAC 2D .1423(g), when considered in
conjunction with other elements in the North Carolina SIP, are
sufficient to provide adequate protection of the NAAQS \164\ and that
the exclusion of emission standards during periods of SSM and regularly
scheduled maintenance activities will not have any adverse impact on
air quality. Indeed, 15A NCAC 2D .1423, including paragraph (g)
thereof, has been in the federally-approved North Carolina SIP for
seventeen years,\165\ and there is no evidence that it has caused or
contributed to any interference with attainment or maintenance of the
NAAQS. Certainly, North Carolina's adoption of 15A NCAC 2D .1423, which
required significant reductions in NOX emissions from large
internal combustion engines, was a SIP strengthening measure even
though the State chose not to apply its limits during SSM events and
scheduled maintenance activities. In fact, Region 4 notes that much of
the text of 15A NCAC 2D .1423, including paragraph (g), is the same as
the text of part of a FIP that EPA proposed but did not need to
finalize in order to meet NOX SIP call emission
budgets.\166\ In other words, EPA itself proposed the same SSM and
maintenance exemptions for NOX emissions from stationary
reciprocating internal combustion engines in 1998 that North Carolina
adopted in 2002.
---------------------------------------------------------------------------

    \163\ The rule revision inserts ``and .1404 of this Section''
following the word ``Rule'' in this text to ensure that the CEMS
used to obtain compliance data must meet the applicable requirements
specified in Rule .1404 (in particular, Paragraphs (d)(2) and (f)(2)
of Rule .1404) as well as the applicable part 60 requirements since
those provisions specify additional Federal requirements for
obtaining CEMS data.
    \164\ North Carolina has bounded the time during which a source
can employ this exemption, minimizing the potential that any excess
emissions during these periods would cause or contribute to a NAAQS
exceedance or violation. Therefore, the exemption, which allows for
emission standards of the rule to not apply during periods of
startup, shutdown, and malfunction of up to 36 consecutive hours, or
maintenance, is not inconsistent with the requirements of the CAA
section 110.
    \165\ See 67 FR 78987 (December 27, 2002).
    \166\ See 63 FR 56394, 56427 (October 21, 1998).
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    Furthermore, Region 4 observes that numerical emission limits
generally cannot be enforced during internal combustion engine startup
because measurement of emissions from this type of unit during startup
is technically infeasible using currently available field

testing procedures.\167\ In addition, internal combustion engines start
up rapidly, typically requiring about 15 minutes to 30 minutes of
operation for the emission control systems to reach an effective
operating temperature.\168\ Likewise, because internal combustion
engines are typically shut down in a matter of minutes,\169\ emissions
during shutdown are also a minor contribution to overall emissions.
Regarding malfunctions, Region 4's understanding is that any
malfunctions by internal combustion engines generally will not cause
violations of applicable emission standards because in most cases these
units shut down immediately or with very little delay.\170\ Maintenance
activities are required to ensure units operate at peak efficiency
during normal operation and that the potential for equipment failure is
minimized. Region 4 is aware of no reason to expect that regular
maintenance activities might cause increased pollutant emission rates.
In conclusion, far from sanctioning unhealthy air emissions as claimed
by commenters, North Carolina's exclusion of periods of SSM and
regularly scheduled maintenance from the emissions standards of 15A
NCAC 2D .1423 is appropriate because internal combustion engine
emissions cannot be accurately measured during such events and because
such events comprise a small fraction of overall unit operating time.
The existing rule, as revised, illustrates a practice on the part of
North Carolina of making informed, reasonable choices, based on
knowledge of the sources they regulate, when developing SIP
requirements and is consistent with the State's overall plan for
improving air quality. Consistent with the U.S. Supreme Court's
direction in Train, Region 4 finds that North Carolina can determine
whatever mix of emission limitations it deems best suited for a
situation, and Region 4 is approving the SIP revision after finding it
complies with the CAA.\171\
---------------------------------------------------------------------------

    \167\ See, e.g., 75 FR 9648, 9665-66 (March 3, 2010) and 75 FR
51570, 51576-77 (August 20, 2010).
    \168\ See, e.g., 74 FR 9698, 9710 (March 5, 2009).
    \169\ Id.
    \170\ Id.
    \171\ Train v. Natural Res. Def. Council, Inc., 421 U.S. 60, 79
(1975).
---------------------------------------------------------------------------

    Region 4 also disagrees with the comment that SSM exemptions in the
North Carolina SIP would frustrate the ozone and SO2
attainment efforts of nearby states. First, as discussed in the
proposal and elsewhere in this final action, the North Carolina SIP
contains numerous provisions that work in concert and provide
redundancy to protect against a NAAQS exceedance or violation, even if
an SSM exemption provision also applies. Therefore, Region 4 has
concluded that it is reasonable for the NC DAQ Director to be able to
exclude qualifying periods of excess emissions during periods of SSM
without posing a significant risk to attainment or maintenance of the
NAAQS. Based on the same rationale, these same provisions of the
State's implementation plan help protect against contribution to air
quality issues outside the State as well. Second, as discussed below,
commenters provide no support for their assertions regarding the
significance of pollutant emissions during any SSM events in North
Carolina and the contribution of those emissions to downwind air
quality issues.
    Regarding the specific concerns raised by the commenter regarding
ozone nonattainment in neighboring states, EPA's recent transport
analyses have demonstrated that emissions from North Carolina do not
significantly contribute to nonattainment or interfere with maintenance
of the ozone NAAQS in downwind states. In the 2011 Cross-State Air
Pollution Rule (CSAPR), EPA determined that emissions from North
Carolina were not linked, and therefore did not contribute, to any
downwind nonattainment receptors (i.e., ambient air quality monitoring
sites) and were linked to two downwind maintenance receptors for the
1997 8-hour ozone NAAQS in its 2012 analytic year.\172\ However, EPA's
analysis in a subsequent action on remand from the D.C. Circuit
demonstrated that those air quality problems would be resolved in 2017
and thus that North Carolina would no longer interfere with maintenance
of the 1997 ozone NAAQS at these receptors.\173\ Moreover, in the 2016
CSAPR Update, EPA determined that North Carolina does not contribute
significantly to nonattainment in, or interfere with maintenance by,
any other state with respect to the 2008 ozone NAAQS because the
State's impact on downwind receptors was well below the threshold used
to identify contributing states.\174\
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    \172\ See 76 FR 48208, Tables V.D-8 and V.D-9 (August 8, 2011).
    \173\ See 81 FR 74504, 74523-524 (October 26, 2016).
    \174\ See 81 FR 74504, 74506, 74537, Table V.E-1 (October 26,
2016).
---------------------------------------------------------------------------

    Regarding the concerns raised by the commenter regarding
SO2 nonattainment in neighboring states, North Carolina does
not currently have any nonattainment areas, as noted earlier in this
document, and commenters provide no specific support for their
assertion that SO2 emissions from North Carolina have an
impact on SO2 attainment issues in downwind states that
would be impacted by the provisions being approved into the SIP.
Because emissions of this pollutant are transformed in the atmosphere
into fine particles (i.e., PM2.5) relatively quickly,\175\
violations of the SO2 NAAQS are generally found in areas
having sources that emit SO2 in quantities large enough,
prior to transformation into fine particles, to cause issues in the
local area.
---------------------------------------------------------------------------

    \175\ For example, in SO2 transport analyses, EPA
focuses on a 50 km-wide zone because the physical properties of
SO2 result in relatively localized pollutant impacts near
an emissions source that drop off with distance. See, e.g., 84 FR
72278, 72280 (December 31, 2019).
---------------------------------------------------------------------------

    Regarding commenters' statement that Sullivan County, Tennessee,
near the North Carolina border, is a nonattainment area for
SO2, the commenters have not explained how this action may
lead to relevant emissions increases in North Carolina likely to affect
this area. The primary SO2-emitting point source located
within the Sullivan County SO2 nonattainment area (Sullivan
County Area) is the Eastman Chemical Company.\176\ The Sullivan County
Area consists of that portion of Sullivan County encompassing a circle
having its center at this facility's B-253 power house and having a 3-
kilometer radius.\177\ North Carolina, on the other hand, has no large
sources of SO2 emissions within 50 km of the Sullivan County
Area. Accordingly, the commenters have not identified any sources of
emissions in North Carolina likely to increase as a result of this
action which would impact the Sullivan County Area.
---------------------------------------------------------------------------

    \176\ See Technical Support Document (TSD), Tennessee Area
Designations For the 2010 SO2 Primary National Ambient
Air Quality Standard, at 8-10, available at https://www.epa.gov/sites/production/files/2016-03/documents/tn-tsd.pdf and in EPA's
docket for the Round 1 Air Quality Designations for the 2010 Sulfur
Dioxide (SO2) Primary National Ambient Air Quality
Standard, 78 FR 47191 (August 5, 2013).
    \177\ See 40 CFR 81.343.
---------------------------------------------------------------------------

    In response to commenters' concern that Mecklenburg County, North
Carolina, is close to violation of the 2015 ozone NAAQS, Region 4 notes
that Mecklenburg County has not violated the 2015 ozone NAAQS. For
North Carolina, in 2012 only the Charlotte-Rock Hill Area (which
includes Mecklenburg County) was designated nonattainment for the 2008
ozone standard of 75 parts per billion (ppb). In 2015, this Area was
redesignated to attainment for that standard. In 2017, the entire State
was designated attainment/unclassifiable for the more protective 2015
ozone standard of 70

ppb.\178\ Region 4 has recently reviewed preliminary data which
indicates the Charlotte-Rock Hill Area will likely still be attaining
the 2015 ozone NAAQS when the 2019 data are certified. While commenters
are correct that ozone concentrations in the Area are near the 2015
ozone standard, this is expected to be due primarily to meteorological
conditions (hotter summers) over the past two years and other factors,
such as increasing mobile emissions. Any increases in ozone design
values in North Carolina cannot reasonably be attributed to SSM
exemptions in 15A NCAC 2D .0535(c) and .0535(g) because those
provisions have been in the SIP for many years and thus have not been a
source of change since that time.
---------------------------------------------------------------------------

    \178\ In 2015 EPA revised the primary and secondary levels of
the ozone standard to 0.070 parts per million to provide increased
public health and welfare protection for the reasons described in
the final published action. See 80 FR 65292 (October 26, 2015).
---------------------------------------------------------------------------

    In response to comments that EPA's approval of attainment and
maintenance plans for certain NAAQS did not consider excess emissions
that may occur, Region 4 agrees that it had no reason to suspect that
excess emissions exempted under Rules 2D .0535(c), 2D .0535(g) and 2D
.1423(g) would be frequent enough or of great enough magnitude to
prevent approval of those plans, and commenters have provided no such
evidence either in this action or in our prior actions approving those
attainment and maintenance plans. North Carolina has an ambient
monitoring network plan that meets or exceeds the requirements of 40
CFR part 58 and is subject to public comment, with the objective of
long-term assessment of air quality. To operate monitors that measure
air pollutant concentrations over the entire State would not be
feasible.
    The State evaluates whether excess emissions qualify for the
exemptions outlined in 15A NCAC 2D .0535(c). For example, over the 5-
year period 2015-2019, Region 4 has received information from North
Carolina indicating 26 malfunction determinations were made by the
State.\179\ Six of those determinations were made on demonstrations
that facilities were required to submit, in accordance with 15A NCAC 2D
.0535(f), because malfunction events resulted in excess emission that
lasted for more than four hours. While North Carolina evaluated all of
the malfunction determinations submitted, NC DAQ determined that twenty
of those submissions were not required to be submitted either because
the excess emission event lasted less than four hours or because no
applicable emission rate limit was exceeded. Also relevant, the State
issued an average of about 300 notices of violation per year for
various operating permit deviations during the same time period.\180\
In addition, as discussed above, the SIP requires that all monitoring
records be retained by the owner or operator and made available for
inspection for a period of two years but does not require automatic
reports to the State for excess emission events that last less than
four hours. In accordance with 15A NCAC 2D .0535(c), no exemption from
violation status is provided for any excess emission event unless the
owner or operator of the source demonstrates to the Director's
satisfaction that the excess emissions are the result of a malfunction.
Such determinations appear to be an infrequent occurrence, having been
made an average of only about five times per year over the past five
years in the State, which has about 300 sources holding title V
operating permits \181\ and over 1,600 sources holding non-title V
operating permits.\182\
---------------------------------------------------------------------------

    \179\ See email and attached spreadsheet from Steve Hall, NC
DAQ, to Joel Huey, EPA, January 9, 2020, included in the docket for
this rulemaking.
    \180\ Obtained from ``NC Air Quality Update,'' Mike
Abraczinskas, Director, NC DAQ, April 11, 2019, slides 25 and 27,
included in the docket for this rulemaking.
    \181\ Id., slide 22.
    \182\ Id.
---------------------------------------------------------------------------

    Region 4 acknowledges the study cited by commenters regarding
excess emissions in Texas. However, the study is specific to emissions
in Texas and does not speak to this action, which is focused on and
limited to an evaluation of the North Carolina SIP, and, as a
corollary, emissions in North Carolina. Region 4 points out that the
referenced study is not from a peer-reviewed journal article and does
not attempt to show a relationship between the occurrence of excess
emissions in Texas and that State's treatment of SSM events. Region 4
also observes that a cursory review of the air emission event reports
\183\ which the study is based upon shows that most of the excess
emissions resulted from industrial flaring events at crude oil and
natural gas production facilities.\184\ This is a circumstance of
particular significance to Texas, which leads the nation in the
production and refining of crude oil and the production and processing
of natural gas.\185\ North Carolina, however, has none of these types
of operations,\186\ and therefore the study is of little relevance the
State's air quality control program. Commenters have provided no
information suggesting that excess emission events exempted under the
North Carolina SIP have been associated with significant adverse
impacts on air quality or human health, and Region 4 is aware of none.
---------------------------------------------------------------------------

    \183\ According to the researchers, only Texas, Oklahoma, and
Louisiana maintain systematic data on excess emissions events that
is usable for research, and Texas publicly posts details regarding
emissions events on its website at https://www2.tceq.texas.gov/oce/eer/.
    \184\ For example, a search on emissions events in all areas
during the period January 1, 2020-January 10, 2020, results in 48
reports filed, at least 75 percent of which were flaring events at
facilities in the crude refining and gas production industries.
    \185\ U.S. Energy Information Administration (EIA), Texas
Profile Data, Reserves, and Supply & Distribution, https://www.eia.gov/state/analysis.php?sid=TX (accessed January 14, 2020).
    \186\ U.S. EIA, North Carolina Profile Data, Reserves, and
Supply & Distribution, https://www.eia.gov/state/analysis.php?sid=NC
(accessed January 14, 2020).
---------------------------------------------------------------------------

    Commenters state that neither EPA nor North Carolina has done any
analysis to evaluate the extent of excess emissions that could be
authorized by the SIP revision, but the SIP revision at issue does not
add or otherwise alter the SSM exemption provisions which are already
in the North Carolina SIP. Further, excess emission events are
difficult to quantify, but Region 4 has evaluated the air quality in
North Carolina and the actual occurrence of such excess emission
events, as explained above. Even though the North Carolina SIP contains
the SSM exemption provisions discussed in this action, air quality in
the State has steadily improved over the years, as discussed in
response to Comment 8, and North Carolina does not currently have any
non-attainment areas.
    Commenter's quote from page 92 of H.R. Rep. No. 95-294 excludes the
context that adds clarity to the intended meaning of the passage. The
statement ``Without an enforceable emission limitation which will be
complied with at all times, there can be no assurance that ambient
standards will be attained and maintained'' is immediately followed by
four more sentences explaining that any emission limitation under the
Act ``must be met on a constant basis, not an `averaging' basis such
as, for example, would be the case if averaging sulfur content of coal
was allowed'' \187\ (as might happen when coals of low-sulfur and high-
sulfur content are combusted at different times). The paragraph
explains that the ``averaging'' method is not allowable because it
cannot provide assurances that an emission limitation will be met at
all times (since inherent to the averaging method is the fact that the
emission limitation would sometimes be

exceeded). In other words, Congress was explaining that an effective
emission limitation is one that reduces emissions continually and is
not one that simply calculates a long-term average of emissions. The
SSM exemptions of the North Carolina SIP provide sources no relief from
their obligation to utilize emission control devices and work practices
to the extent practicable, and they are not an emission averaging
scheme.
---------------------------------------------------------------------------

    \187\ H.R. Rep. No. 95-294, at 92 (1977).
---------------------------------------------------------------------------

    Regarding the commenters' statement that ``one known event released
165,000 pounds of sulfur dioxide,'' Region 4 observes that the
referenced event occurred in Louisiana in October 2011.\188\ A report
about this specific event, completed by the Louisiana Department of
Environmental Quality Inspection Division, states the incident was
preventable and ``will be referred as an AOC on LAC 33:111.905.A''
(i.e., an Administrative Order on Consent for violating Louisiana
Administrative Code 33:111.905.A, which requires proper use of emission
controls). Thus, the referenced event, which occurred almost nine years
ago in a state other than North Carolina, was not exempted by that
state but instead was identified as requiring an administrative order
to correct the problem that caused the exceedance. While Region 4
acknowledges that air pollutant emissions can be higher than normal
during SSM events, commenters have provided no viable evidence
supporting their contention that excess emissions which are exempted
from violation status release ``huge amounts'' of pollution or that
they have a significant impact on attainment and maintenance of the
NAAQS, particularly not from the State of North Carolina, and Region 4
is aware of none.
---------------------------------------------------------------------------

    \188\ See ``Louisiana Department of Environmental Quality Intra-
Agency Routing Form'' (December 8, 2011) included in the docket for
this rulemaking.
---------------------------------------------------------------------------

    Region 4 also disagrees that this action exempts excess emission
events from regulation. The SIP-called provisions do not automatically
exempt emissions during SSM; they provide for use of Director's
discretion, which Region 4 expects would exempt fewer excess emission
events than an automatic exemption. This action will not cause an
increase in emissions because the SIP-called provisions were approved
by EPA in 1986 and 1997 and have been in effect, without interruption,
since those approvals. Similarly, as referenced above, the automatic
exemption in 15A NCAC 2D .1423 has been in the North Carolina SIP since
2002, and that approval is also not impacted by this action. Therefore,
this action is not expected to have any adverse impact on air quality.
While EPA stated in the 2015 SSM SIP Action that the Agency was
concerned about the potential for serious adverse consequences for
public health during the interim period in which states, EPA and
sources took measures necessary to respond to the SSM SIP call, the
Agency made no finding of actual harm, in qualitative or quantitative
terms, from the provisions called for revision. Rather, EPA discussed
at length the assertion that ``EPA does not interpret section 110(k)(5)
to require proof that a given SIP provision caused a specific
environmental harm or undermined a specific enforcement action in order
to find the provision substantially inadequate.'' \189\ EPA did not
make a specific factual finding regarding actual harm in North Carolina
when it issued the SIP call in 2015, and no factual finding is required
for Region 4 to adopt an alternative interpretation of the statutory
provisions at issue. The proposal and this final action provide a
comprehensive rationale for Region 4's alternative policy and its
change in interpretation.
---------------------------------------------------------------------------

    \189\ See 80 FR at 33932-34.
---------------------------------------------------------------------------

    As explained in the June 5, 2019, NPRM, the NAAQS have been set to
provide requisite protection, including an adequate margin of safety,
for human health.\190\ The purpose of the SIP is to ensure compliance
with the NAAQS, e.g., attainment and maintenance. EPA has an obligation
to approve SIP revisions if the Agency does not determine it will
negatively impact a state's ability to attain or maintain the NAAQS.
Region 4 views the various overlapping planning requirements of the
North Carolina SIP as sufficient to meet the requirements of CAA
section 110. Commenters have not provided sufficient evidence to
suggest that the SIP revisions approved in this action would prevent
North Carolina from attaining or maintaining the NAAQS.
---------------------------------------------------------------------------

    \190\ See 84 FR at 26034.
---------------------------------------------------------------------------

11. Comments on Director's Discretion Provisions

    Comment 11: Commenters state that EPA cannot reasonably conclude
the NAAQS will be protected if NC DAQ's Director can exempt SSM
emissions from being violations. Commenters argue that SIP-called
provisions list seven criteria for the Director to consider, but does
not limit consideration to those criteria and notes that the terms are
open to subjective interpretation and that the Director may abuse
discretionary authority, which can lead to NAAQS violations. Commenters
claim that even if all of the conditions required to qualify as a
malfunction under the North Carolina SIP have occurred, the criteria
rely on subjective terms. The one mandatory provision, commenters
state, relies on the subjective term ``as practicable.'' Commenters
also state that even if applied stringently, start up and shut down
emissions could be ``minimized'' but still be high enough to cause a
NAAQS exceedance and that such events could occur often enough to cause
a violation of the NAAQS.
    Response 11: Based on review of the information Region 4 has
regarding malfunction determinations made by the Director of the NC DAQ
from 2015 through 2019, as discussed above in Response 10, we believe
that the Director has employed the discretionary authority provided by
North Carolina's 15A NCAC 2D .0535(c) in circumstances that are
narrower than an exemption that would apply automatically during such
events. Also, Region 4 anticipates that, going forward, emissions
exempted by the Director pursuant to 15A NCAC 2D .0535(c) will continue
to apply to a narrower scope of emissions than would be exempt through
an automatic exemption. Additionally, as discussed above, 15A NCAC 2D
.0535(g) directs facilities, during startup and shutdown, to operate
all equipment in a manner consistent with best practicable air
pollution control practices to minimize emissions and to demonstrate
that excess emissions were unavoidable when requested to do so by the
Director. Therefore, based on the evaluation of the North Carolina SIP
in Section III of this final action and Sections III and IV of the
proposal, Region 4 reasonably concludes that the Director's discretion
provisions in the North Carolina SIP are not inconsistent with CAA
requirements because the North Carolina SIP, when evaluated as a whole,
provides for attainment and maintenance of the NAAQS.
    Further, the federally-approved North Carolina SIP has contained a
provision providing Director's discretion for malfunction exemptions
for over 30 years; \191\ the commenter has not provided any evidence to
demonstrate that the existence of such provisions interfered with North
Carolina's attainment or maintenance of any NAAQS. In fact, as
discussed in response to Comment 8, air quality in North Carolina has
continued to improve over time and there are not

currently any nonattainment areas in the state. Commenters have not
pointed to evidence of abuse of Director's discretion in North
Carolina. Region 4 cannot respond to unsubstantiated claims regarding
abuses of discretionary authority by the Director of the State air
agency. Region 4 is not aware of any evidence of such abuses since the
introduction of the Director's discretion provision into the North
Carolina SIP.
---------------------------------------------------------------------------

    \191\ 15A NCAC 2D .0535(c) was approved on September 9, 1986 (51
FR 32073), and 15A NCAC 2D .0535(g) was approved on August 1, 1997
(62 FR 41277).
---------------------------------------------------------------------------

    Region 4 acknowledges that a Director's determination of whether
emissions are excusable pursuant to 15A NCAC 2D .0535(c) or .0535(g)
may be somewhat subjective \192\ but maintains that the Director will
be acting in accordance with approved SIP provisions. Further, as
discussed in Section III of this final action, the provisions do not
prevent the United States or citizens from enforcing the underlying
provisions. The exercise of authority under the Director's discretion
provisions of 15A NCAC 2D .0535 shall not be construed to bar,
preclude, or otherwise impair the right of action by the United States
or citizens to enforce a violation of an emission limitation or
emission standard in the SIP or a permit where the demonstration by a
source or a determination by the Director does not comply with the
framework and authority under 15A NCAC 2D .0535. Failure to comply with
such framework and authority would invalidate the Director's
determination. EPA and citizens' ability to enforce the underlying
provisions is another element contributing to Region 4's conclusion
that the SSM exemption provisions do not interfere with NAAQS
attainment and that the SIP is consistent with the CAA.
---------------------------------------------------------------------------

    \192\ Pursuant to various other North Carolina SIP provisions,
the Director has authority to exercise his or her judgment with
respect to several other types of determinations. See, e.g., 15A
NCAC 2D .0501(f)(2) (requiring demonstration ``to the satisfaction
of the Director''); 15A NCAC 2D .0530(t)(3) and .0531(m)(4)
(requiring demonstrations ``to the Director's satisfaction''); 15A
NCAC 2D .0540(h) (requiring correction of facility's fugitive dust
control plan where ``the Director finds that the plan inadequately
controls fugitive dust emissions''); 15A NCAC 2D .2602(i)
(authorizing Director to allow deviations from testing procedures
required under the SIP).
---------------------------------------------------------------------------

12. Comments on Enforcement

    Comment 12: Commenters state that the North Carolina SIP provisions
relied upon in the proposal are mere platitudes and have very little
probability of being effective in practice. Commenters state that the
cited SIP provisions that prohibit violations of the NAAQS are not
practicably enforceable. Commenters identify gaps in information for
malfunction events and whether a NAAQS violation occurs, including a
general statement that NAAQS monitoring stations are not generally
located around most sources. Commenters further assert that EPA must
assume that absence of a documented NAAQS violation will be treated as
sufficient proof that a violation did not occur. Commenters conclude
that consequently, few exemptions are expected to be denied even if the
excess emissions, in reality, caused a violation.
    Commenters assert that North Carolina's procedures for obtaining an
exemption are generally appropriate for an approach based on
enforcement discretion, but point out that EPA and citizen enforcement
would be limited. Commenters state that EPA can be assumed to exercise
appropriate enforcement discretion and that citizen enforcement does
not generally result in unfair outcomes for sources. Commenters
conclude that EPA could revisit its national policy and revert to one
that applied for decades in which SSM exemptions are not allowed except
via enforcement discretion, and all SIP emission limits apply
continuously. Commenters state that alternative emission limits could
be developed for periods of SSM as well.
    Commenters state that Congress required continuously applicable
emission limitations to ensure citizens would have meaningful access to
the remedy provided by the Act's citizen-suit provision to assure
compliance with emission limitations and other requirements of the Act
but that exemptions remove citizens' ability to enforce emission
limitations and thus contravene the Act.
    Response 12: Commenters provide no concrete evidence that the
provisions relied upon in the North Carolina SIP have a low probability
of being effective in practice. Generally speaking, as discussed in
response to Comment 8, North Carolina's air quality has continued to
improve in recent years, and no areas of North Carolina are currently
designated nonattainment for any NAAQS. Commenters have not provided
information indicating that the existence of the SSM exemption
provisions in the SIP have precluded enforcement or that the Director
in North Carolina has abused his or her discretion. Commenters provide
no basis for speculating that they expect the North Carolina Director
to deny few exemption demonstrations, even if a violation occurred.
Detailed information about historical usage of director's discretion
provisions in the North Carolina SIP is included in our response to
Comment 10 above.
    Region 4 disagrees with the comment that allowing Director's
discretion SSM exemption provisions to remain in the North Carolina SIP
will hamper citizen enforcement, in contravention of the CAA
requirements. As discussed in Section III of this final action, the
exercise of authority under the Director's discretion provisions of 15A
NCAC 2D .0535 shall not be construed to bar, preclude, or otherwise
impair the right of action by the United States or citizens to enforce
a violation of an emission limitation or emission standard in the SIP
or a permit where the demonstration by a source or a determination by
the Director does not comply with the framework and authority under 15
NCAC 2D .0535. Failure to comply with such framework and authority
would invalidate the Director's determination. North Carolina's comment
letter on the proposed SSM SIP Call \193\ similarly indicates that the
Director's discretion exemption provisions are not intended to prevent
enforcement: ``[n]othing in the existing SIP provisions prohibits or
restricts in any way the ability of EPA and/or a citizen to file an
action in federal court seeking enforcement of the SIP provisions.''
\194\
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    \193\ See 78 FR 12460 (February 22, 2013).
    \194\ Letter from Sheila C. Holman, Director, NC DAQ, to EPA,
May 13, 2013, page 3, Docket ID: EPA-HQ-OAR-2012-0322-0619,
available at www.regulations.gov.
---------------------------------------------------------------------------

    Emissions information for sources in North Carolina is available
and obtainable, and commenters have not presented information
indicating otherwise. As discussed above, the SIP requires that excess
emissions lasting more than four hours be reported to the State at 15A
NCAC 2D .0535. Additionally, title V permits require semiannual reports
to include deviations from applicable requirements as well as annual
compliance certifications at 15A NCAC 2Q .0508. This information
assists the Director in determining whether a NAAQS violation likely
occurred. North Carolina also makes public the inspection reports,
compliance reports, and other materials related to emissions compliance
at facilities. Further, NC DAQ maintains records of determinations of
malfunctions available for public inspection in its compliance database
(accessible at https://deq.nc.gov/about/divisions/air-quality/air-quality-compliance). This information is available for title V sources,
small permitted sources, and small exempt (non-permitted) sources.
    In response to the comment regarding the monitoring network, Region
4 notes

that the EPA works collaboratively with states and tribes to monitor
air quality for each criteria pollutant, as well as air toxics, through
ambient air monitoring networks. North Carolina has an ambient
monitoring network plan that meets or exceeds the requirements of 40
CFR part 58 and is subject to public comment, with the objective of
long-term assessment of air quality. The data collected serve as one of
the factors for determining whether an area is attaining the NAAQS,
based on the form of the standard and design value calculation for each
standard.
    Region 4 notes that North Carolina has an approved monitoring
network plan, pursuant to 40 CFR part 58.\195\ In accordance with EPA
regulatory requirements, NC DAQ maintains a network of 40 monitoring
stations across the state and measures the concentration of pollutants
subject to the NAAQS. Several monitors operated by the State are indeed
source-oriented where required by EPA or deemed appropriate by the
state due to local impacts of certain types of pollutants. For example,
in accordance with EPA's Data Requirements Rule for the 2010 1-Hour
SO2 Primary NAAQS (80 FR 51052, August 21, 2015), the State
operates several SO2 monitors near large sources of
SO2 emissions.\196\
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    \195\ North Carolina's 2019-2020 monitoring network plan was
approved by EPA on February 7, 2020.
    \196\ See North Carolina Div. of Air Quality, 2019-2020 Annual
Monitoring Network Plan for the North Carolina Division of Air
Quality (October 15, 2019), available at https://files.nc.gov/ncdeq/Air%20Quality/monitor/monitoring_plan/NC-Network-Plan.pdf.
---------------------------------------------------------------------------

    Region 4 acknowledges that alternative emission limits may also be
included in the North Carolina SIP. The State has flexibility to adopt
``whatever mix of emission limitations it deems best suited to its
particular situation.'' \197\ This could include alternative emission
limitations, but, as Region 4 has concluded in this document, in the
context of North Carolina's entire SIP, North Carolina's exemption
provisions are also acceptable.
---------------------------------------------------------------------------

    \197\ Train, 421 U.S. at 79.
---------------------------------------------------------------------------

13. Comments That SIP Submissions Must be Evaluated Independently, not
in Context of SIP Overall

    Comment 13: Commenters state that section 110 of the Act makes
clear that EPA actions on SIPs must also depend on whether a SIP or
submittals meet all of the applicable requirements of the Act.
Commenters conclude that EPA may not accept a SIP, approve a
submission, or withdraw a SIP Call by asserting that the approved SIP,
as a whole, operates continuously to ensure attainment and maintenance
of the NAAQS if such SIP, submission or withdrawal means the SIP would
not meet all of the applicable requirements of the CAA. Commenters
conclude that the proposal contradicts the plain language and plain
meaning of the CAA by dispensing with the independent legal requirement
that SIPs, submissions or withdrawals of a SIP Call ensure compliance
with all applicable requirements of the Act.
    Response 13: As described in Section III of this final action,
Region 4's policy interpretation is not inconsistent with any
applicable requirements of the CAA. Section III of this document fully
explains Region 4's interpretation of the interplay between sections
110 and 302(k), which provides a reasonable and permissible
interpretation of these provisions, even though it differs from prior
interpretations. Not only did Region 4 determine to take this action
and approve this SIP revision based on an understanding that the SIP
will continue to be protective of the NAAQS, this action and SIP
approval are consistent with the statutory interpretations offered in
this document. Region 4 has a reasonable basis to conclude, upon
evaluation and consideration of the protective requirements contained
in the SIP as a whole, that the provisions which create exemptions for
excess emissions that may occur during periods of SSM events do not
preclude approvability of the North Carolina SIP.
    The alternative policy announced in this action, which provides an
interpretation of CAA sections 110 and 302 that supports Region 4's
decision to withdraw the SIP Call, is not inconsistent with the
applicable requirements of the CAA, including the provisions cited by
the commenters at CAA 110(k)(3), (k)(5), and (l). In Section III of
this final action, Region 4 withdraws the SIP Call that was issued in
the 2015 SSM SIP action with respect to 15A NCAC 2D .0535(c) and 15A
NCAC 2D .0535(g), and makes a finding that these SIP provisions are not
inconsistent with CAA requirements. Region 4 is approving the changes
to 15A NCAC 2D .1423 submitted by the State on June 5, 2017, because it
has determined that the change is in compliance with all applicable CAA
requirements.

14. Comments of a Miscellaneous or General Nature

    Comment 14: Commenters state that, in retrospect, EPA in the 2015
SSM SIP Call should not have concluded that alternative emission
limitations during periods of SSM could be established, particularly in
the timeframe necessary for the corrective SIPs.
    Response 14: This comment is not in scope for this rulemaking.
Region 4 cannot address comments received about the referenced June 12,
2015, action.

VI. Incorporation by Reference

    In this document, Region 4 is finalizing regulatory text that
includes incorporation by reference. In accordance with requirements of
1 CFR 51.5, Region 4 is finalizing the incorporation by reference of
15A NCAC 2D .1423--``Large Internal Combustion Engines,'' state
effective July 15, 2002, which is modified to clarify applicability,
correct typos, standardize exclusions, clarify that alternative
compliance methods must show compliance status of the engine, clarify
by adding the word ``shall'' and revising language to better define
ozone season, and clarify that CEMS records must identify the reason
for, the action taken to correct, and the action taken to prevent
excess emissions. EPA has made, and will continue to make, these
materials generally available through www.regulations.gov and at the
EPA Region 4 Office (please contact the person identified in the FOR
FURTHER INFORMATION CONTACT section of this preamble for more
information). Therefore, these materials have been approved by Region 4
for inclusion in the SIP, have been incorporated by reference by Region
4 into that plan, are fully federally enforceable under sections 110
and 113 of the CAA as of the effective date of the final rulemaking of
Region 4's approval, and will be incorporated by reference in the next
update to the SIP compilation.\198\
---------------------------------------------------------------------------

    \198\ See 62 FR 27968 (May 22, 1997).
---------------------------------------------------------------------------

VII. Final Action

    Region 4 is withdrawing the SIP call issued to North Carolina for
15A NCAC 2D .0535(c) and 15A NCAC 2D .0535(g) pursuant to CAA section
110(k)(5), originally published on June 12, 2015. In connection with
this withdrawal, Region 4 finds that these State regulatory provisions
included in the North Carolina SIP are not substantially inadequate to
meet CAA requirements.
    Pursuant to section 110 of the CAA, Region 4 is approving the
aforementioned changes to 15A NCAC 2D .1423 and incorporating these
changes into the North Carolina SIP. Region 4 has evaluated the changes
to 15A NCAC 2D .1423 as included in North Carolina's June 5, 2017, SIP

revision, and has determined that they meet the applicable requirements
of the CAA and its implementing regulations.

VIII. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the Act and applicable
Federal regulations. See 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in
reviewing SIP submissions, EPA's role is to approve state choices,
provided they meet the criteria of the CAA. This action approves state
law as meeting Federal requirements and does not impose additional
requirements beyond those imposed by state law. For that reason, this
action:
     Is not a significant regulatory action subject to review
by the Office of Management and Budget under Executive Orders 12866 (58
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
     Is not an Executive Order 13771 (82 FR 9339, February 2,
2017) regulatory action because SIP approvals are exempted under
Executive Order 12866;
     Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
     Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the CAA; and
     Results from on a new interpretation and does not provide
EPA with the discretionary authority to address, as appropriate,
disproportionate human health or environmental effects, using
practicable and legally permissible methods, under Executive Order
12898 (59 FR 7629, February 16, 1994).
    The SIP is not approved to apply on any Indian reservation land or
in any other area where EPA or an Indian tribe has demonstrated that a
tribe has jurisdiction. In those areas of Indian country, the rule does
not have tribal implications as specified by Executive Order 13175 (65
FR 67249, November 9, 2000), nor will it impose substantial direct
costs on tribal governments or preempt tribal law.
    Under section 307(b)(1) of the CAA, petitions for judicial review
of this action must be filed in the United States Court of Appeals for
the appropriate circuit by June 29, 2020. Filing a petition for
reconsideration by the Administrator of this final rule does not affect
the finality of this action for the purposes of judicial review nor
does it extend the time within which a petition for judicial review may
be filed, and shall not postpone the effectiveness of such rule or
action. This action may not be challenged later in proceedings to
enforce its requirements. (See section 307(b)(2).)

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Nitrogen dioxide, Ozone,
Reporting and recordkeeping requirements, Volatile organic compounds.

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

Mary Walker,
Regional Administrator, Region 4.

    40 CFR part 52 is amended as follows:

PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

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

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

Subpart II--North Carolina

0
2. Amend Sec.  52.1770(c)(1), under ``Subchapter 2D Air Pollution
Control Requirements,'' by revising the entry for ``Section .1423'' to
read as follows:

Sec.  52.1770  Identification of plan.

* * * * *
    (c) * * *

                                   (1) EPA Approved North Carolina Regulations
----------------------------------------------------------------------------------------------------------------
                                                                State
          State citation                Title/subject      effective date    EPA approval date      Explanation
----------------------------------------------------------------------------------------------------------------
                                Subchapter 2D Air Pollution Control Requirements
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------
                                          Section .1400 Nitrogen Oxides
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
Section .1423.....................  Large Internal              7/15/2002  4/28/2020, [Insert
                                     Combustion Engines.                    citation of
                                                                            publication].

                                                  * * * * * * *
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* * * * *
[FR Doc. 2020-07512 Filed 4-27-20; 8:45 am]
 BILLING CODE 6560-50-P