Document ID: EPA-R04-OAR-2019-0303-0030
Agency: epa
Document Type: Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: North Carolina; Large Internal Combustion Engines NOX Rule Changes; State Implementation Plan Call Withdrawal and Air Plan Approval
Posted Date: 2020-04-28T04:00Z

[Federal Register Volume 85, Number 82 (Tuesday, April 28, 2020)]
[Rules and Regulations]
[Pages 23700-23730]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-07512]

[[Page 23699]]

Vol. 85

Tuesday,

No. 82

April 28, 2020

Part IV

Environmental Protection Agency

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40 CFR Part 52

SIP Call Withdrawal and Air Plan Approval; NC: Large Internal 
Combustion Engines NOX Rule Change; Final Rule

  Federal Register / Vol. 85 , No. 82 / Tuesday, April 28, 2020 / Rules 
and Regulations  

[[Page 23700]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2019-0303; FRL-10007-76-Region 4]

SIP Call Withdrawal and Air Plan Approval; NC: Large Internal 
Combustion Engines NOX Rule Changes

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA), Region 4 is 
approving a portion of a State Implementation Plan (SIP) revision 
submitted by the State of North Carolina, through the North Carolina 
Division of Air Quality (NC DAQ), in a letter dated June 5, 2017, which 
changes North Carolina's SIP-approved rule regarding nitrogen oxides 
(NOX) emissions from large internal combustion engine 
sources. In so doing, Region 4 is first adopting an alternative policy 
regarding startup, shutdown, and malfunction (SSM) exemption provisions 
in the North Carolina SIP that departs from the national policy on this 
subject, as described in EPA's June 12, 2015 action (2015 SSM SIP Call 
Action). Accordingly, Region 4 is also withdrawing the SIP Call issued 
to North Carolina for exemptions contained in the State's existing SIP-
approved provisions for SSM events. This action is limited to the SIP 
Call issued to North Carolina and the associated evaluation of the 
North Carolina SIP and does not otherwise change or alter EPA's 2015 
SSM SIP Call Action.

DATES: This rule is effective on May 28, 2020.

ADDRESSES: EPA has established a docket for this action under Docket ID 
No. EPA-R04-OAR-2019-0303. All documents in the docket are listed on 
the www.regulations.gov website. Although listed in the index, some 
information is not publicly available, i.e., Confidential Business 
Information or other information whose disclosure is restricted by 
statute. Certain other material, such as copyrighted material, is not 
placed on the internet and will be publicly available only in hard copy 
form. Publicly available docket materials are available either 
electronically through www.regulations.gov or in hard copy at the Air 
Regulatory Management Section, Air Planning and Implementation Branch, 
Air and Radiation Division, U.S. Environmental Protection Agency, 
Region 4, 61 Forsyth Street SW, Atlanta, Georgia 30303-8960. EPA 
requests that if at all possible, you contact the person listed in the 
FOR FURTHER INFORMATION CONTACT section to schedule your inspection. 
The Regional Office's official hours of business are Monday through 
Friday 8:30 a.m. to 4:30 p.m., excluding Federal holidays.

FOR FURTHER INFORMATION CONTACT: Joel Huey, Air Planning and 
Implementation Branch, Air and Radiation Division, U.S. Environmental 
Protection Agency, Region 4, 61 Forsyth Street SW, Atlanta, Georgia 
30303-8960. Mr. Huey can be reached by phone at (404) 562-9104 or via 
electronic mail at huey.joel@epa.gov.

SUPPLEMENTARY INFORMATION: 

Table of Contents

    The following topics are discussed in this preamble:
I. Background for This Action
II. EPA's SSM SIP Policy and SIP Call Issued to North Carolina
III. Region 4's Alternative Policy on Automatic and Director's 
Discretion Exemption Provisions in the North Carolina SIP and 
Withdrawal of the North Carolina SIP Call
IV. Region 4's Action on North Carolina's June 5, 2017, SIP Revision
V. Responses to Comments
VI. Incorporation by Reference
VII. Final Action
VIII. Statutory and Executive Order Reviews

I. Background for This Action

    On June 5, 2019, EPA Region 4 announced that it was considering 
adopting an alternative policy regarding startup, shutdown and 
malfunction (SSM) exemptions in state implementation plans (SIPs), and, 
if adopted, also proposed to withdraw the SIP Call issued to North 
Carolina in 2015 and to approve a SIP revision submitted by NC DAQ in 
2017.\1\ The 60-day comment period closed on August 5, 2019. Region 4 
received public comments, all of which are included in the public 
docket for this action at www.regulations.gov. This document includes 
summaries of the adverse comments received and responses to those 
comments. After reviewing and carefully considering the comments 
received, as described more fully in this document, Region 4 is (1) 
adopting an alternative policy applicable to North Carolina for SSM 
exemption provisions in the North Carolina SIP and withdrawing the SIP 
Call issued to North Carolina, and (2) approving the SIP revision 
submitted by NC DAQ, through a letter dated June 5, 2017, which seeks 
to change North Carolina's SIP-approved rule regarding NOX 
emissions from large internal combustion engine sources at 15A N.C. 
Admin. Code (NCAC) 2D .1423.
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    \1\ SIP Call Withdrawal and Air Plan Approval; NC: Large 
Internal Combustion Engines NOX Rule Changes, Proposed 
Rule, 84 FR 26031 (June 5, 2019). Hereafter, the June 5, 2019, 
notice of proposed rulemaking will be referred to as the June 5, 
2019, NPRM.
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    Relevant to this action, in the 2015 SSM SIP Call Action (80 FR 
33840 (June 12, 2015)) EPA restated its national policy prohibiting the 
inclusion of provisions in SIPs that exempt excess emissions during 
periods of SSM. In that action, EPA also issued findings that certain 
SIP provisions in 36 states (applicable in 45 statewide and local 
jurisdictions) were substantially inadequate to meet the Clean Air Act 
(CAA or Act) requirements and thus issued ``SIP Calls'' pursuant to CAA 
section 110(k)(5) for all of those states and local jurisdictions.\2\ 
That action includes a SIP Call for North Carolina to address two 
specific provisions in the State's implementation plan that provide 
discretion to the State agency to exempt emissions from being 
considered a violation of an otherwise applicable State rule, in 
certain circumstances.\3\ Also relevant, the June 5, 2017, SIP 
submission Region 4 is approving in this action revises a different 
provision in the North Carolina code that was not included in the 2015 
SSM SIP Call Action, but which includes a sub-provision that 
automatically exempts periods of SSM, not to exceed 36 consecutive 
hours, and scheduled maintenance activities from regulation.\4\
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    \2\ See State Implementation Plans: Response to Petition for 
Rulemaking; Restatement and Update of EPA's SSM Policy Applicable to 
SIPs; Findings of Substantial Inadequacy; and SIP Calls To Amend 
Provisions Applying to Excess Emissions During Periods of Startup, 
Shutdown and Malfunction; Final Rule, 80 FR 33839 (June 12, 2015).
    \3\ Id. at 33964. EPA issued a SIP Call to North Carolina 
regarding provisions 15A NCAC 2D .0535(c) and 15A NCAC 2D .0535(g).
    \4\ 15A NCAC 02D .1423 was not included in the 2015 SSM SIP Call 
Action because, in that action, EPA elected to first focus its 
review on the specific provisions that had already been identified 
by Sierra Club in its petition regarding the SSM SIP Call. See 80 FR 
at 33880.
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    The rationale for the alternative policy on SSM exemptions that 
Region 4 is applying to the North Carolina SIP is articulated in 
Section III of this document and in Sections III and IV of the June 5, 
2019, NPRM.\5\ Region 4's decision to withdraw the SIP Call previously 
issued to North Carolina is substantiated by the adoption of the 
alternative policy. Region 4's approval of the revision to North 
Carolina's SIP-approved rule regarding NOX emissions from 
large internal combustion engine sources at 15A NCAC 2D .1423 is 
described in Section IV of this

[[Page 23701]]

document and Section V of the June 5, 2019, NPRM.\6\
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    \5\ See 84 FR at 26033-39.
    \6\ Id. at 26039-040.
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II. EPA's SSM SIP Policy and SIP Call Issued To North Carolina

    In the final 2015 SSM SIP Call Action, EPA updated and restated its 
national policy regarding provisions in SIPs that exempt periods of SSM 
events from otherwise applicable emission limitations. Referencing 
previously issued guidance documents and regulatory actions, the Agency 
expressed its interpretation of the CAA that SIP provisions cannot 
include exemptions from emission limitations for emissions during SSM 
events.\7\ EPA's position in the 2015 SSM SIP Call Action, based in 
part on D.C. Circuit precedent, was that the general definitions 
provision of the CAA providing that an emission limitation must apply 
to a source ``continuously'' means that an approved SIP cannot include 
periods during which emissions from sources are legally or functionally 
exempt from regulation.
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    \7\ See 80 FR at 33976.
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    Also in the 2015 SSM SIP Call Action, the Agency defined the term 
``automatic exemption'' as a generally applicable SIP provision that 
does not consider periods of excess emissions as violations of an 
applicable emission limitation if certain conditions existed during the 
exceedance period.\8\ The Agency defined a ``director's discretion 
provision'' as a regulatory provision that authorizes a state 
regulatory official to grant exemptions or variances from otherwise 
applicable emission limitations or to otherwise excuse noncompliance 
with applicable emission limitations, where the regulatory official's 
determination would be binding on EPA and the public.\9\ The Agency 
defined ``emission limitation'' in the SIP context, relying on the 
general definition set forth in CAA section 302 (``Definitions''), as a 
legally binding restriction on emissions from a source or source 
category, such as a numerical emission limitation, a numerical emission 
limitation with higher or lower levels applicable during specific modes 
of source operation, a specific technological control measure 
requirement, a work practice standard, or a combination of these things 
as components of a comprehensive and continuous emission 
limitation.\10\ As stated in the 2015 SSM SIP Call Action, the Agency 
took the position that an emission limitation ``must be applicable to 
the source continuously, i.e., cannot include periods during which 
emissions from the source are legally or functionally exempt from 
regulation.'' \11\
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    \8\ Id. at 33977.
    \9\ Id.
    \10\ Id.
    \11\ Id.
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    Relying substantially on its interpretation of the general 
definition of ``emission limitation'' in CAA section 302(k)--
specifically, that that definition provides for the limitation of 
emissions of air pollutants ``on a continuous basis''--the Agency 
explained its position that exemptions from emission limitations in 
SIPs, whether automatic or discretionary, are not permissible in 
SIPs.\12\ EPA explained that even a brief exemption from an otherwise 
applicable limit would render the emission limitation non-continuous 
and therefore not consistent with the CAA section 302(k) definition of 
``emission limitation.'' \13\
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    \12\ Id.
    \13\ Id.
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    With respect to discretionary exemptions, the Agency took the 
position that a regulatory official's grant of an exemption pursuant to 
a ``director's discretion'' exemption could result in air agency 
personnel modifying a SIP requirement without going through the CAA 
statutory process for SIP revisions.\14\ In the 2015 SSM SIP Call 
Action, the Agency did allow that some director's discretion exemptions 
could be included in SIPs, if those exemptions were structured such 
that variances or deviations from the otherwise applicable emission 
limitation or SIP requirement were not valid as a matter of Federal law 
unless and until EPA approved the exercise of the director's discretion 
as a SIP revision.\15\
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    \14\ Id. at 33918 (referencing CAA sections 110(k)(3), which 
establishes the framework for EPA to fully or partially approve SIP 
submittals, and 110(l) and 193, which specify that revisions to SIPs 
must be submitted to EPA and can be approved only if the 
Administrator determines that the revisions meet specific 
requirements, including non-interference with attainment and 
reasonable further progress and equivalent or greater emission 
reductions in nonattainment areas). See also id. at 33977-78.
    \15\ Id. at 33978.
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    As further support for the Agency's position on excluding SSM 
exemption provisions in SIPs, the 2015 SSM SIP Call Action relied on 
Sierra Club v. Johnson.\16\ In that 2008 case, the D.C. Circuit 
evaluated the validity of an SSM exemption in the General Provisions 
\17\ of EPA rules issued under CAA section 112 (``Hazardous Air 
Pollutants''). Reading CAA sections 112 and 302(k) together, the D.C. 
Circuit found that ``the SSM exemption violates the CAA's requirement 
that some section 112 standard apply continuously.'' \18\ In the 2015 
SSM SIP Call Action, EPA interpreted the Sierra Club decision regarding 
CAA section 112 requirements and applied the reasoning of that decision 
to the requirements of EPA's rules issued under CAA section 110 
(``Implementation Plans''), specifically CAA section 110(a)(2)(A), 
which provides that SIPs shall include ``enforceable emission 
limitations and other control measures, means, or techniques . . . as 
may be necessary or appropriate to meet the applicable requirements of 
this chapter.'' \19\ EPA's application of the Sierra Club decision to 
CAA section 110 SIP requirements was based on an understanding that the 
D.C. Circuit was interpreting the definition of ``emission limitation'' 
in CAA section 302(k) that applies generally to the Act. Following this 
reasoning, EPA determined that Sierra Club was consistent with the 
Agency's position, as expressed in previously issued guidance documents 
and regulatory actions that prohibited exemption provisions for 
otherwise applicable emission limits in SIPs (such as automatic 
exemptions granted for SSM events).\20\
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    \16\ 551 F.3d 1019 (D.C. Cir. 2008).
    \17\ Subpart A of 40 CFR part 63 (``National Emission Standards 
for Hazardous Air Pollutants for Source Categories'').
    \18\ Sierra Club, 551 F.3d at 1027-28.
    \19\ See 42 U.S.C. 7410(a)(2)(A) (emphasis added).
    \20\ See, e.g., 80 FR at 33852, 33874, 33892-94.
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    As part of the 2015 SSM SIP Call Action, EPA found that 15A NCAC 2D 
.0535(c) and 15A NCAC 2D .0535(g) were substantially inadequate to meet 
CAA requirements because they allow exemptions from otherwise 
applicable emission limitations for excess emissions \21\ that may 
occur during malfunctions and during periods of startup and shutdown, 
respectively, at the discretion of the state agency.\22\ On that basis, 
EPA issued a SIP Call pursuant to CAA section 110(k)(5) to North 
Carolina with respect to these provisions.
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    \21\ The North Carolina SIP defines excess emissions as ``an 
emission rate that exceeds any applicable emission limitation or 
standard allowed by any regulation in Sections .0500 or .0900 of 
this Subchapter or by a permit condition.'' In this final action, we 
clarify that exemptions allowed under rules 2D .0535(c) and 2D 
.0535(g) apply only to numerical emission limits of the North 
Carolina SIP and do apply to any of the SIP's requirements to 
utilize emission control devices or to employ work practice 
standards that reduce emissions.
    \22\ See 80 FR at 33964.

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[[Page 23702]]

III. Region 4's Alternative Policy on Automatic and Director's 
Discretion Exemption Provisions in the North Carolina SIP and 
Withdrawal of the North Carolina SIP Call

A. Automatic Exemption Provisions

    As discussed in the June 5, 2019, NPRM, in reviewing the North 
Carolina SIP revision at issue, as well as the North Carolina SIP in 
its entirety, Region 4 has considered the national policy regarding SSM 
exemptions \23\ in SIPs included in the 2015 SSM SIP Call Action, 
described above, and has determined that there is a reasonable 
alternative way for Region 4 to consider SSM provisions in the North 
Carolina SIP: after evaluating the SIP comprehensively and determining 
that the SIP, as a whole, is protective of the national ambient air 
quality standards (NAAQS or standards), Region 4 concludes that 
automatic SSM exemptions are allowable in that SIP.\24\ Further, the 
alternative policy's interpretation of the relevant CAA provisions, 
together with the specific automatic SSM provisions in the North 
Carolina SIP, make it reasonable for Region 4 to find that the SIP 
meets the applicable requirements of the CAA and therefore do not 
mandate a finding that the SIP is substantially inadequate.
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    \23\ Throughout this document, we use the term ``exemption'' to 
refer to automatic exemptions for SSM events in general; specific 
references to director's discretion provisions are referred to as 
``director's discretion exemptions.''
    \24\ The 2015 SSM SIP Call Action explained that while a SIP may 
contain provisions that apply during periods of SSM, the 
applicability of those provisions was not plain on the face of the 
SIP provision. See generally 80 FR at 33943. As explained in this 
document, EPA Region 4 has determined that, for the North Carolina 
SIP, it is reasonable to take a broader perspective of evaluation of 
the SIP and its provisions that ensure attainment and maintenance of 
the NAAQS.
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    The compilation of state and Federal requirements in the North 
Carolina SIP result from the Federal-state partnership that is the 
foundation of the CAA, as well as the various requirements of the Act. 
Although the North Carolina SIP contains SSM exemptions for limited 
periods applicable to discrete standards, the SIP is composed of 
numerous planning requirements that are collectively NAAQS-protective. 
The North Carolina SIP's overlapping requirements, described more fully 
later in this section, provide additional protection of the standards 
such that Region 4 concludes that the SIP adequately provides for 
attainment and maintenance of the NAAQS, even if the SIP allows 
exemptions to specific emission limits for discrete periods, such as 
SSM events. This redundancy helps to ensure attainment and maintenance 
of the NAAQS, one of the goals of Congress when it created the SIP 
adoption and approval process in the CAA.\25\ The fact that North 
Carolina does not currently have any nonattainment areas for any NAAQS, 
even though the exemption provisions have been included in the State's 
implementation plan, supports the conclusion that the SSM exemptions do 
not interfere with attainment and maintenance of the NAAQS.\26\ Region 
4 appropriately considered all of these factors when evaluating the 
North Carolina SIP.
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    \25\ See, e.g., H.R. Rep. No. 91-1783 at 193-95 (1970).
    \26\ As of the effective date of this document, no areas of 
North Carolina are designated nonattainment for any NAAQS. See 
https://www3.epa.gov/airquality/greenbook/ancl3.html.
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    At the outset, Region 4 notes that it maintains discretion and 
authority to change its CAA interpretation from a prior position. In 
FCC v. Fox Television Stations, Inc., the U.S. Supreme Court plainly 
stated an agency's obligation with respect to changing a prior policy:

    We find no basis in the Administrative Procedure Act or in our 
opinions for a requirement that all agency change be subjected to 
more searching review. The Act mentions no such heightened standard. 
And our opinion in State Farm neither held nor implied that every 
agency action representing a policy change must be justified by 
reasons more substantial than those required to adopt a policy in 
the first instance.\27\
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    \27\ See 556 U.S. 502, 514 (2009) (referencing Motor Vehicle 
Mfrs. Ass'n of United States, Inc. v. State Farm Mut. Auto. Ins. 
Co., 463 U.S. 29 (1983)).

    In cases where an agency is changing its position, the Court stated 
that a reasoned explanation for the new policy would ordinarily 
``display awareness that it is changing position'' and ``show that 
there are good reasons for the new policy.'' \28\ In so doing, the 
Court emphasized that the agency ``need not demonstrate . . . that the 
reasons for the new policy are better than the reasons for the old one; 
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.'' \29\ In cases where a new policy ``rests upon factual 
findings that contradict those which underlay its prior policy; or when 
its prior policy has engendered serious reliance interests that must be 
taken into account,'' the Court found that a more detailed 
justification might be warranted than what would suffice for a new 
policy.\30\
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    \28\ Id. at 515.
    \29\ Id.
    \30\ Id. at 515-16.
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    As discussed above, the 2015 SSM SIP Call Action updated and 
restated EPA's SSM policy that SIPs containing any type of SSM 
exemptions were not approvable because exemptions from emission 
limitations created the possibility that a state could not ensure 
attainment or maintenance of the NAAQS for one or more criteria 
pollutants. This policy is predicated on the idea that a requirement 
limiting emissions would not apply ``on a continuous basis''-- and thus 
would not itself constitute an ``emission limitation''--if the SIP 
permitted exemptions for any period of time from that requirement.\31\ 
Under this policy, the lack of a continuous standard was viewed as 
creating a substantial risk that exemptions could permit excess 
emissions that could ultimately result in a NAAQS violation. Region 4 
acknowledges the policy position updated and restated in the 2015 SSM 
SIP Call Action, and the associated rationale. However, as will be 
discussed further in this section, Region 4 has determined that the 
general requirements in CAA section 110 to attain and maintain the 
NAAQS and the latitude provided to states through the SIP development 
process create a framework in which a state may be able to ensure 
attainment and maintenance of the NAAQS notwithstanding the presence of 
SSM exemptions in the SIP. Further, for the reasons articulated in this 
document, Region 4 has concluded that the automatic SSM exemptions in 
the North Carolina SIP do not mandate a finding of substantial 
inadequacy pursuant to CAA section 110(k)(5) or preclude a finding 
under CAA section 110(k)(3) that the SIP meets all of the applicable 
requirements of the CAA. Additionally, as discussed in Section IV, and 
consistent with the policy rationale explained in this document, Region 
4 has determined that the SIP revision will not interfere with 
attainment, reasonable further progress, or any other applicable 
requirement of the CAA.
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    \31\ See 42 U.S.C. 7602(k) (providing the general definition of 
``emission limitation'' and ``emission standard'').
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    Consistent with the interpretation provided in the June 5, 2019, 
NPRM, this alternative policy is reasonable because the D.C. Circuit's 
decision in Sierra Club does not, on its face, apply to SIPs and 
actions taken under CAA section 110. In the 2015 SSM SIP Call Action at 
80 FR 33839, EPA extended the legal reasoning of the D.C. Circuit's 
Sierra Club decision regarding SSM exemptions from CAA section 112 
rules to CAA section 110 SIP approved rules; that extension of the 
Sierra Club decision supported the Agency's

[[Page 23703]]

existing position that SSM exemptions were inconsistent with CAA SIP 
requirements. At the time, the Agency interpreted CAA section 302(k) as 
applying uniformly and requiring that the ``emission limitations'' 
required under the CAA, whether under section 110 or section 112, be 
continuous as a general matter.\32\ Further consideration of the issue 
has shown that an alternative reading of the application of the Sierra 
Club decision to CAA section 110 is reasonable, and consideration of 
the facts surrounding the SIP revision submitted by the State of North 
Carolina, and an evaluation of the North Carolina SIP as a whole, show 
that such an interpretation is appropriate in this instance. Simply 
stated, while the Sierra Club decision did not allow sources to be 
exempt from complying with CAA section 112 emission limitations during 
periods of SSM, that finding is not necessarily binding on CAA section 
110 and EPA's consideration of SIPs under that section.
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    \32\ See 80 FR at 33874.
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    The interpretation offered in this document is informed by and 
consistent with the distinct structures and purposes of CAA sections 
110 and 112. As explained in the June 5, 2019, NPRM, the D.C. Circuit 
in Sierra Club specifically referred to CAA section 112 when it framed 
Petitioners' argument and found that the Agency ``constructively 
reopened consideration of the exemption from section 112 emission 
standards during SSM events.'' \33\ The court's analysis reads the 
definition of emission limitation and standard at CAA section 302(k) in 
the context of CAA section 112: ``When sections 112 and 302(k) are read 
together then, Congress has required that there must be continuous 
section 112-compliant standards.'' \34\ Further, specific to CAA 
section 112 rules, the court explained, ``[i]n requiring that sources 
regulated under section 112 meet the strictest standards, Congress gave 
no indication that it intended the application of [maximum achievable 
control technology] standards to vary based on different time 
periods.'' \35\ In Sierra Club, the court found that when EPA 
promulgates standards pursuant to CAA section 112, CAA section 112-
compliant standards must apply continuously. The stringency of CAA 
section 112 was thus an important element of the court's decision,\36\ 
and the court did not make any statement explicitly applying its CAA 
section 112-dependent holding beyond the emissions standards 
promulgated under CAA section 112.
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    \33\ Sierra Club, 551 F.3d at 1026.
    \34\ Id. at 1027.
    \35\ Id. at 1028.
    \36\ See id. at 1027 (``Section 112(d) provides that 
`[e]missions standards' promulgated thereunder must require MACT 
standards.''); id. at 1028 (explaining that Congress intended that 
``sources regulated under section 112 meet the strictest 
standards.'').
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    While EPA chose to rely on the Sierra Club decision in the 2015 SSM 
SIP Call Action, such reliance was not required--the court's decision 
does not speak to whether the rationale articulated with respect to SSM 
exemptions in CAA section 112 standards necessarily applies to SIPs 
submitted and reviewed under CAA section 110. As discussed below, the 
Sierra Club decision, on its face, does not interpret section 110, and 
there are valid reasons for not extending the reasoning to the North 
Carolina SIP provisions at issue. CAA section 112 sets forth a 
prescriptive standard-setting framework; CAA section 110 does not. CAA 
sections 112 and 110 have different goals and establish different EPA 
roles in implementation. Given the Sierra Club decision's singular 
focus on CAA section 112 standards, and the vastly different purposes 
and implementation approaches between CAA sections 110 and 112, there 
is a reasonable basis for interpreting the Sierra Club decision as only 
applying to CAA section 112.
    The purpose of CAA section 112 is fundamentally different than the 
purpose of CAA section 110. Importantly, the court in Sierra Club 
recognized that Congress intended ``that sources regulated under 
section 112 meet the strictest standards.'' \37\ As described in the 
June 5, 2019, NPRM, under CAA section 112, once a source category is 
listed for regulation pursuant to CAA section 112(c), the statute 
directs EPA to use a specific and exacting process to establish 
nationally applicable, category-wide, technology-based emissions 
standards under CAA section 112(d).\38\ Under CAA section 112(d), EPA 
must establish emission standards for major sources that ``require the 
maximum degree of reduction in emissions of the hazardous air 
pollutants subject to this section'' that EPA determines is achievable 
taking into account certain statutory factors.\39\ EPA refers to these 
rules as ``maximum achievable control technology'' or ``MACT'' 
standards. The MACT standards for existing sources must be at least as 
stringent as the average emission limitation achieved by the best 
performing 12 percent of existing sources in the category (for which 
the Administrator has emissions information) or the best performing 
five sources for source categories with less than 30 sources.\40\ This 
level of minimum stringency is referred to as the MACT floor. For new 
sources, MACT standards must be at least as stringent as the control 
level achieved in practice by the best controlled existing similar 
source.\41\ EPA also must analyze more stringent ``beyond-the-floor'' 
control options, for which consideration is given not only to the 
maximum degree of reduction in emissions of a hazardous air pollutant, 
but also to the costs, energy, and non-air quality health and 
environmental impacts.\42\
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    \37\ Id. at 1028.
    \38\ EPA can also set work practices under CAA section 112(h).
    \39\ See 42 U.S.C. 7412(d)(2) (emphasis added).
    \40\ See 42 U.S.C. 7412(d)(3)(A), (B).
    \41\ See 42 U.S.C. 7412(d)(3).
    \42\ See Cement Kiln Recycling Coal. v. EPA, 255 F.3d 855, 857-
58 (D.C. Cir. 2001).
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    In contrast, the CAA sets out a fundamentally different regime with 
respect to CAA section 110 SIPs, reflecting the principle that SIP 
development and implementation is customizable for each state's 
circumstances and relies on the Federal-state partnership.\43\ CAA 
section 110(a)(2)(A) requires states to adopt, and include in their SIP 
submissions, ``enforceable emission limitations and other control 
measures, means, or techniques (including incentives such as fees, 
marketable permits, and auctions of emissions rights) . . . as may be 
necessary or appropriate to meet the applicable requirements of this 
Act.'' \44\ The CAA sets forth the minimum requirements to attain, 
maintain, and enforce air quality standards, while allowing each state 
to identify and effectuate an approach that is appropriate for the 
sources and air quality challenges specific to each state.\45\ CAA 
section 109(a) directs the EPA Administrator to promulgate primary and 
secondary NAAQS for pollutants for which air quality criteria have been 
issued. For each criteria pollutant, CAA section 109(b)(1) directs the 
Administrator to establish a primary NAAQS based on the attainment and 
maintenance of which there is an adequate margin of safety as required 
to

[[Page 23704]]

protect public health. Similarly, CAA section 109(b)(2) directs the 
Administrator to establish secondary standards based on the attainment 
and maintenance of which there is an adequate margin of safety as 
required to protect the public welfare from known or anticipated 
adverse effects associated with the presence of such pollutants in 
ambient air. Based on the scientific and technical information 
available at the time of issuing a standard, EPA identifies the level 
of the NAAQS for each criteria pollutant as a means of setting a target 
for state and regional air quality planning. The standard-setting 
process related to the regulation of pollutants in ambient air, as 
directed by section 109 and as implemented by section 110 of the CAA, 
is therefore fundamentally different in nature than the process for 
setting stringent source-specific standards that EPA is required to 
issue under CAA section 112. The D.C. Circuit's concern that CAA 
section 112-compliant standards must apply ``continuously'' to regulate 
emissions from a particular source does not translate directly to the 
context of CAA section 110, where a state's plan may contain a broad 
range of measures, including limits on multiple sources' and source 
categories' emissions of multiple pollutants--all working together to 
ensure attainment and maintenance of an ambient standard that is not 
itself an applicable requirement for individual sources. Importantly, 
regardless of the measures a state seeks to include in its SIP, those 
measures must collectively work toward compliance with the nationally 
uniform NAAQS.
---------------------------------------------------------------------------

    \43\ See, e.g., Virginia v. EPA, 108 F.3d 1397, 1408 (D.C. Cir. 
1997) (``EPA `identifies the end to be achieved, while the states 
choose the particular means for realizing that end.' '') (quoting 
Air Pollution Control Dist. v. EPA, 739 F.2d 1071, 1074 (D.C. Cir. 
1984)). See also, e.g., H.R. Rep. No. 95-294, 95th Cong. 1st Sess. 
at 213 (explaining that for nonattainment areas, Congress intended 
to ``give the States more flexibility in determining how to protect 
public health while still permitting reasonable new growth'') (May 
12, 1977).
    \44\ See 42 U.S.C. 7410(a)(2)(A) (emphasis added).
    \45\ See Virginia v. EPA, 108 F.3d at 1408.
---------------------------------------------------------------------------

    The Fourth Circuit has acknowledged that ``[s]tates are accorded 
flexibility in determining how their SIPs are structured'' to ensure 
that the state meets the NAAQS.\46\ Further, the U.S. Supreme Court has 
recognized that the CAA gives a state ``wide discretion'' to formulate 
its plan pursuant to CAA section 110 and went so far as to say that 
``the State has virtually absolute power in allocating emission 
limitations so long as the national standards are met.'' \47\ The U.S. 
Supreme Court has also explained, ``so long as the ultimate effect of a 
State's choice of emission limitations is compliance with the national 
standards for ambient air, the State is at liberty to adopt whatever 
mix of emission limitations it deems best suited to its particular 
situation.'' \48\ State and Federal Government divide this 
responsibility, which results in a balance of state and Federal rights 
and responsibilities. States typically have primary responsibility for 
determining how and to what extent to regulate sources within the state 
to comply with NAAQS.\49\ In fact, EPA has implemented guidance 
addressing a number of requirements in CAA section 110 and explained 
that SIPs could satisfy the requirements of CAA section 110(a)(2)(A) by 
simply ``identify[ing] existing EPA-approved SIP provisions or new SIP 
provisions . . . that limit emissions of pollutants relevant to the 
subject NAAQS.'' \50\ Given their understanding of emission sources and 
air quality within their jurisdictions, states are uniquely suited and 
well-equipped to determine how best to implement the NAAQS in light of 
their particular local needs. Comments from NC DAQ emphasize that the 
State ``has a long and successful history of implementing [the NAAQS 
attainment and maintenance] framework in North Carolina'' and notes 
that ``all NAAQS are being met in the state.'' \51\ NC DAQ lauds 
Federal, state and local partnerships for the successful 
implementation.\52\
---------------------------------------------------------------------------

    \46\ North Carolina ex rel. Cooper v. TVA, 615 F.3d 291, 299 
(4th Cir. 2010).
    \47\ See, e.g., Union Elec. Co. v. EPA, 427 U.S. 246, 250 & 267 
(1976). See also id. at 269 (``Congress plainly left with the 
States, so long as the national standards were met, the power to 
determine which sources would be burdened by regulation and to what 
extent.''). Commenters challenged the proposal's reliance on the 
Union Electric and Train decisions, but do not disagree with Region 
4's basis for relying on the decisions, specifically that they 
establish that states are afforded discretion regarding how to 
develop SIPs. The alternative policy's explanation, detailed below, 
that North Carolina may provide exemptions from numerical emission 
limits because its SIP contains a set of emission limitations, 
control means, or other means or techniques, which, taken as a 
whole, meet the requirements of attaining and maintaining the NAAQS 
negates commenters' assertion that the Agency is authorizing North 
Carolina to adopt emission limitations or standards that violate the 
CAA.
    \48\ Train v. Natural Res. Def. Council, Inc., 421 U.S. 60, 79 
(1975).
    \49\ See, e.g., Mirant Potomac River, LLC v. EPA, 577 F.3d 223, 
227 (4th Cir. 2009) (``Under Title I, states have the primary 
responsibility for assuring that air quality within their borders 
meets the NAAQS. Title I requires each state to create a State 
Implementation Plan . . . to meet the NAAQS.'').
    \50\ See September 13, 2013, Memorandum from Stephen D. Page, 
``Guidance on Infrastructure State Implementation Plan (SIP) 
Elements under Clean Air Act Sections 110(a)(1) and 110(a)(2)'' at 
page 18.
    \51\ Comment Letter submitted by NC DAQ, EPA-R04-OAR-2019-0303-
0020.
    \52\ Id.
---------------------------------------------------------------------------

    Region 4 received comments challenging the reliance on Train and 
the associated line of cases because in the 2015 SSM SIP Call Action 
the Agency viewed Train as not authorizing exemptions in SIPs. However, 
acknowledging the prior interpretation, in this action, Region 4 has 
evaluated the North Carolina SIP and is adopting an alternative 
approach, consistent with the Region's interpretation of the 
flexibility afforded pursuant to CAA section 110(a)(2)(A) and the Train 
decision. Incorporating the explanation provided in the NPRM, Region 4 
maintains that because the North Carolina SIP includes numerous 
protective provisions and evidence shows that the SIP is ensuring 
attainment and maintenance of the NAAQS, it is appropriate to rely on 
the flexibility afforded to states by Train in this circumstance.
    The statutory text of CAA section 110(a)(2)(A) reflects this EPA-
state cooperative relationship, providing state flexibility that simply 
does not exist in the text of CAA section 112, as outlined earlier in 
this section. CAA section 110(a)(2)(A) generally requires that each SIP 
shall include ``enforceable emission limitations and other control 
measures, means, or techniques (including economic incentives such as 
fees, marketable permits, and auctions of emissions rights), as well as 
schedules and timetables for compliance, as may be necessary or 
appropriate to meet the applicable requirements of this chapter.'' \53\ 
EPA has never interpreted this provision to require the type of 
exacting analysis set forth in CAA section 112, and the flexibility 
Congress gave states in section 110 warrants a differing 
interpretation. The presumption of consistent usage--that a word or 
phrase is presumed to bear the same meaning throughout a text--only 
``makes sense when applied . . . pragmatically.'' \54\ It is 
appropriate, and pragmatic, for Region 4 to consider the distinct 
frameworks and purposes of CAA sections 110 and 112 when implementing 
the term ``emission limitation'' in evaluating the North Carolina SIP.
---------------------------------------------------------------------------

    \53\ See 42 U.S.C. 7410(a)(2)(A).
    \54\ Antonin Scalia & Bryan A. Garner, Reading Law: The 
Interpretation of Legal Texts 171 (Thompson/West) (2012).
---------------------------------------------------------------------------

    The U.S. Supreme Court has recognized that principles of statutory 
construction are not so rigid as to necessarily require that the same 
terminology has the exact same meaning in different parts of the same 
statute.\55\ Terms can have ``different shades of meaning,'' reflecting 
``different implementation strategies'' even when used in the same 
statute.\56\ Emphasizing that ``[c]ontext counts,'' the Court explained 
that ``[t]here is . . . no effectively irrebuttable presumption that 
the same defined term in different provisions of the same statute must 
be

[[Page 23705]]

interpreted identically.'' \57\ Contrary to assertions by commenters, 
the distinct purposes of CAA sections 110 and 112 provide the relevant 
context that justifies Region 4's decision to interpret the definition 
of emission limitation or standard differently in the two provisions. 
As opposed to assertions from commenters who disagreed with the June 5, 
2019, NPRM's discussion of the Duke Energy decision, the interpretation 
of CAA sections 302(k) and 110(a)(2)(A) advanced in this document does 
not disregard the concept of continuity from CAA section 302(k), nor 
does it nullify the provision's meaning. Rather, the concept of 
continuity is acknowledged and afforded significance through the fact 
that the North Carolina SIP in which such emission limitations exist, 
as a whole, applies continuously. The concept of continuous ``emission 
limitations'' in a SIP need not be focused on continuous implementation 
of each individual limit, but rather on the approved SIP as a whole and 
whether the SIP operates continuously to ensure attainment and 
maintenance of the NAAQS.
---------------------------------------------------------------------------

    \55\ See Envtl. Def. v. Duke Energy Corp., 549 U.S. 561, 574 
(2007).
    \56\ Id. at 574 (citations omitted).
    \57\ Id. at 575-76.
---------------------------------------------------------------------------

    Region 4's interpretation is consistent with the concept that the 
CAA requires that some section 110 standard apply continuously. 
Specifically, CAA 110(a)(2)(A) requires the SIP to include 
``enforceable emission limitations and other control measures, means, 
or techniques (including economic incentives such as fees, marketable 
permits, and auctions of emissions rights), as well as schedules and 
timetables for compliance, as may be necessary or appropriate to meet 
the applicable requirements of this Act.'' The phrase ``as may be 
necessary or appropriate to meet the applicable requirements of [the] 
Act'' explicitly allows the State some flexibility to develop SIP 
provisions that are best suited for their purposes. In this context, 
Region 4 finds that a reasonable interpretation of the section 302(k) 
definition of the terms ``emission limitation'' and ``emission 
standard'' does not preclude North Carolina from adopting provisions 
that apply continuously while also allowing that unavoidable excess 
emissions that occur during certain discrete, time-limited periods of 
operation may not be considered a violation of the rule. This is 
consistent with Region 4's determination that the North Carolina SIP, 
considered as a whole, meets the requirements of the Act. But even if 
commenters are correct that ``enforceable emission limitations'' must 
be interpreted as a single limit that applies continuously and without 
exempt periods, Region 4 finds that North Carolina's SIP provisions 
that include periods of exemptions are not inconsistent with the CAA 
under the latter part of provision 110(a)(2)(A) as ``other control 
measures, means or techniques . . . as may be necessary or appropriate 
to meet the applicable requirements of [the] Act'' \58\ (emphasis 
added).
---------------------------------------------------------------------------

    \58\ Region 4 also notes that this interpretation is consistent 
with language in the CAA definition of ``Federal Implementation 
Plan'' (FIP) (i.e., a plan, or portion thereof, promulgated by the 
Administrator to fill all or a portion of a gap or otherwise correct 
all or a portion of an inadequacy in a SIP). The definition, at 
section 302(y), states that a FIP ``includes enforceable emission 
limitations or other control measures, means or techniques 
(including economic incentives, such as marketable permits or 
auctions of emissions allowances), and provides for attainment of 
the relevant national ambient air quality standard'' (emphasis 
added). This language clarifies that ``other control measures, means 
or techniques'' is an approach that is separate from ``enforceable 
emission limitations'' and thus does not invoke the 302(k) 
definition of ``emission limitation.''
---------------------------------------------------------------------------

    Region 4 interprets CAA section 110(a)(2)(A) to mean a state may 
provide exemptions from numerical emission limits so long as the SIP 
contains a set of emission limitations, control means, or other means 
or techniques, which, taken as a whole, meet the requirements of 
attaining and maintaining the NAAQS under subpart A. As supported by NC 
DAQ's comment letter \59\ on the NPRM and as this section further 
elaborates, our evaluation of the North Carolina SIP shows this to be 
the case. The State has a combination of emission limits that apply 
``as may be necessary or appropriate'' during normal operations but 
with exemptions during SSM periods and ``other control measures, means, 
or techniques'' that remain applicable during periods of SSM in which 
the exemptions apply--such as general duty provisions in the SIP, work 
practice standards, best management practices, or alternative emission 
limits--and are protective of the NAAQS. Additionally, SIPs are 
required to include entirely separate provisions, such as minor source 
review and major source new source review provisions regulating 
construction or modification of stationary sources, that also 
effectively limit emissions of NAAQS pollutants within the state. North 
Carolina regulates the construction and modification of sources to 
prevent significant deterioration of air quality in areas already 
attaining the NAAQS, or to allow improvement of air quality while still 
providing for growth in areas not meeting the NAAQS, through 15A NCAC 
2D .0530 and 2D .0531. Thus, as the U.S. Supreme Court explained in 
Duke Energy that a term may be interpreted differently when justified 
by different contexts (in this case different parts of the same 
statute), the CAA definition of an emission limitation in section 
302(k), when read in the context of section 110, could mean states may, 
at their discretion, provide exemptions from specific numerical 
emission limits during periods when it is not practicable or necessary 
for such limits to apply, so long as the SIP contains other provisions 
that remain in effect and ensure the NAAQS are protected. Region 4 
evaluated the North Carolina SIP and determined it is not inconsistent 
with CAA requirements for the SIP to contain such exemption provisions 
because the State's overlapping protective requirements sufficiently 
ensure overall attainment and maintenance of the NAAQS.
---------------------------------------------------------------------------

    \59\ Letter from Michael A. Abraczinskas, Director, NC DAQ, to 
EPA, August 5, 2019, Docket ID No. EPA-R04-OAR-2019-0303-0001 for 
this rulemaking.
---------------------------------------------------------------------------

    Consistent with this interpretation, Region 4 has evaluated the 
North Carolina SIP as a whole and has determined that the SIP contains 
numerous provisions intended to assure that air quality standards will 
be achieved, as explained below. Any provisions allowing exemptions for 
periods of SSM do not alter the applicability of these general SIP 
requirements. In analyzing the air quality protections provided by the 
entirety of the North Carolina SIP, Region 4 concludes that the SIP 
contains overlapping planning requirements that are protective of each 
individual criteria pollutant NAAQS. In fact, both provisions that were 
included in the 2015 SSM SIP Call Action for North Carolina include 
substantial protection of air quality standards within the SIP-called 
provision itself.
    First, as Region 4 outlined in the June 5, 2019, NPRM, the 
exemption provided at 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. 
Specifically, it states:

    Start-up and shut-down. Excess emissions during start-up and 
shut-down shall be considered a violation of the appropriate rule if 
the owner or operator cannot demonstrate that the excess emissions 
are unavoidable when requested to do so by the Director. The 
Director may specify for a particular source the amount, time, and 
duration of emissions that are allowed during start-up or shut-down. 
The owner or operator shall, to the extent practicable, operate the 
source and any associated air pollution control

[[Page 23706]]

equipment or monitoring equipment in a manner consistent with best 
practicable air pollution control practices to minimize emissions 
during start-up and shut-down. (Emphasis added.)

    Even though this provision includes an exemption, it also provides 
a backstop that requires sources to use the best practicable air 
pollution control practices to minimize emissions during startup or 
shutdown periods.
    Second, the exemption provided at NCAC 2D .0535(c) outlines seven 
criteria that the director will consider when evaluating whether the 
source qualifies for an emissions limit exemption during a malfunction. 
Specifically, it states:

    Any excess emissions that do not occur during start-up or shut 
down shall be considered a violation of the appropriate rule unless 
the owner or operator of the source of the excess emissions 
demonstrates to the director, that the excess emissions are the 
result of a malfunction. To determine if the excess emissions are 
the result of a malfunction, the director shall consider, along with 
any other pertinent information, the following:
    (1) The air cleaning device, process equipment, or process has 
been maintained and operated, to the maximum extent practicable, in 
a manner consistent with good practice for minimizing emissions;
    (2) Repairs have been made in an expeditious manner when the 
emission limits have been exceeded;
    (3) The amount and duration of the excess emissions, including 
any bypass have been minimized to the maximum extent practicable;
    (4) All practical steps have been taken to minimize the impact 
of the excess emissions on ambient air quality;
    (5) The excess emissions are not part of a recurring pattern 
indicative of inadequate design, operation, or maintenance;
    (6) The requirements of Paragraph (f) of the Regulation have 
been met; and
    (7) If the source is required to have a malfunction abatement 
plan, it has followed that plan.
    All malfunctions shall be repaired as expeditiously as 
practicable. However, the director shall not excuse excess emissions 
caused by malfunctions from a source for more than 15 percent of the 
operating time during each calendar year.

    The existence of these specific criteria themselves provide 
additional protections of the NAAQS because factors considered by the 
director include whether sources minimize emissions and limit the 
extent of emissions which could occur to the greatest extent 
practicable. Additionally, the provision itself establishes bounds on a 
source's ability to employ this exemption by prohibiting the Director 
from excusing excess emissions from a source due to malfunctions for 
more than 15 percent of the operating time. This limitation reasonably 
minimizes the risk that excess emissions from malfunctions would 
contribute to a NAAQS exceedance or violation.
    Apart from the SIP-called provisions discussed above, as discussed 
in the June 5, 2019, NPRM, the North Carolina SIP also contains 
numerous overlapping requirements providing for protection of air 
quality and the NAAQS, requirements that generally control emissions of 
NAAQS pollutants. Each of these provisions ensures that emissions are 
minimized to protect air quality, independent of an SSM exemption that 
may also apply. Described as follows, these generally applicable 
requirements collectively support Region 4's alternative policy for the 
North Carolina SIP.
    First, 15A NCAC 2D .0502, which is included in the North Carolina 
SIP and addresses emission control standards generally, provides: ``The 
purpose of the emission control standards set out in this Section is to 
establish maximum limits on the rate of emission air contaminants into 
the atmosphere. All sources shall be provided with the maximum feasible 
control.'' \60\ The requirement for ``maximum feasible control'' on all 
sources applies at all times, including periods of startup and 
shutdown. Thus, by requiring sources to be subject to emission control 
standards established at the maximum feasible level of control, the SIP 
ensures that air quality in the State will be protected to the highest 
degree possible. This guiding purpose broadly applies to the emission 
control standards in Section .0500 of the North Carolina SIP. North 
Carolina confirmed as much in their comment letter on EPA's 2015 SSM 
policy, explaining that the State's requirement that sources implement 
``maximum feasible control'' is one of the provisions of the SIP that 
``provide assurances that air quality and emission standards will be 
achieved.'' \61\ In light of the flexibility in CAA section 
110(a)(2)(A) and SIP development generally, North Carolina has 
developed a reasonable overall emissions control approach that requires 
all sources to implement maximum feasible emission control efforts at 
all times, even though the State may exempt sources from numerical 
emission limits during some SSM periods.
---------------------------------------------------------------------------

    \60\ See 40 CFR 52.1770(c)(1).
    \61\ Letter from Sheila C. Holman, Director, NC DAQ, to EPA, May 
13, 2013, page 2, Docket ID No. EPA-HQ-OAR-2012-0322-0619, available 
at www.regulations.gov.
---------------------------------------------------------------------------

    Second, the North Carolina SIP includes general provisions that 
require sources not to operate in such a way as to cause NAAQS 
violations. 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, despite the SIP containing SSM exemptions for emission 
limitations. 15A NCAC 2D .0501(e) states:

    In addition to any control or manner of operation necessary to 
meet emission standards in this Section, any source of air pollution 
shall be operated with such control or in such manner that the 
source shall not cause the ambient air quality standards of Section 
.0400 of this Subchapter to be exceeded at any point beyond the 
premises on which the source is located. When controls more 
stringent than named in the applicable emission standards in this 
Section are required to prevent violation of the ambient air quality 
standards or are required to create an offset, the permit shall 
contain a condition requiring these controls.

    Accordingly, even if the SIP contains exemptions from numerical 
emission limits during SSM events, this provision ensures that the 
source at issue must ensure that none of its emissions cause a NAAQS 
exceedance or violation, consistent with the primary purpose of CAA 
section 110.
    Third, the North Carolina SIP provides additional assurances that 
sources will prevent and correct equipment failures that could result 
in excess emissions by requiring 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. Utility boilers in 
North Carolina contribute a significant portion of the point source 
pollutant emissions in the State.\62\ 15A NCAC 2D .0535(d) states:
---------------------------------------------------------------------------

    \62\ For example, utility boilers in North Carolina contribute 
approximately 24 percent of PM10 emissions, 66 percent of 
SO2 emissions, and 47 percent of NOX emissions 
from total point sources in the State. See spreadsheet titled ``NC 
2014 NEI Summary'' in the docket for this action.

    All electric utility boiler units subject to a rule in this 
section shall have a malfunction abatement plan approved by the 
director. In addition, the director may require any source that he 
has determined to have a history of excess emissions to have a 
malfunction abatement plan approved by the director. The malfunction 
plans of electric utility boiler units and of other sources required 
to have them shall be implemented when a malfunction or other 
breakdown occurs. The purpose of the malfunction abatement plan is 
to prevent, detect, and correct malfunctions or equipment failures 
---------------------------------------------------------------------------
that could result in excess emissions. . . .

    This provision goes on to describe the minimum requirements for a 
malfunction abatement plan, including:

[[Page 23707]]

(1) A complete preventive maintenance program (including identification 
of the individual responsible for inspecting, maintaining and repairing 
air cleaning devices; description of the items or conditions that will 
be inspected and maintained; the frequency of the inspection, 
maintenance services, and repairs; and identification and quantities of 
the replacement parts that shall be maintained in inventory for quick 
replacement); (2) the procedures for detecting a malfunction or failure 
(including identification of the source and air cleaning operating 
variables and outlet variables; the normal operating range of those 
variables; and a description of the monitoring method or surveillance 
procedures and of the system for alerting operating personnel of any 
malfunctions); and (3) a description of the corrective procedures that 
will be taken to achieve compliance with the applicable rule as 
expeditiously as practicable in case of a malfunction or failure.\63\ 
Although specific to electric utility boilers (and other sources as 
required by the Director), this SIP provision ensures that subject 
units are taking steps to prevent, detect, and correct malfunctions, 
even if an SSM exemption applies. This provision serves to limit any 
excess emissions that could result from such events, thus reducing the 
possibility that any excess emissions would result in a NAAQS 
exceedance or violation.
---------------------------------------------------------------------------

    \63\ See 15A NCAC 2D .0535(d)(1)-(3).
---------------------------------------------------------------------------

    Fourth, the North Carolina SIP provides general provisions to 
reduce airborne pollutants and to prevent NAAQS exceedances beyond 
facility property lines, despite the SIP containing SSM exemptions for 
numerical emission limits, for particulates from sand, gravel, or 
crushed stone operations and from lightweight aggregate operations (at 
15A NCAC 2D .0510(a) and 0511(a), respectively):

    The owner or operator of a [. . .] operation shall not cause, 
allow, or permit any material to be produced, handled, transported 
or stockpiled without taking measures to reduce to a minimum any 
particulate matter from becoming airborne to prevent exceeding the 
ambient air quality standards beyond the property line for 
particulate matter, both PM10 and total suspended 
particulates.

    And in a similar manner, the North Carolina SIP includes general 
provisions to reduce airborne pollutants and to prevent NAAQS 
exceedances beyond facility property lines for particulates from wood 
products finishing plants (at 15A NCAC 2D .0512):

    A person shall not cause, allow, or permit particulate matter 
caused by the working, sanding, or finishing of wood to be 
discharged from any stack, vent, or building into the atmosphere 
without providing, as a minimum for its collection, adequate duct 
work and properly designed collectors, or such other devices as 
approved by the commission, and in no case shall the ambient air 
quality standards be exceeded beyond the property line.

    Accordingly, even if the SIP contains exemptions from numerical 
emission limits during SSM events, these provisions ensure that the 
source at issue must ensure that none of its emissions cause a NAAQS 
exceedance or violation.
    Fifth, the North Carolina SIP provides a general requirement at 15A 
NCAC 2D .0521(g) for sources that operate continuous opacity monitoring 
systems (COMS) that ``[i]n no instance shall excess [opacity] emissions 
exempted under this Paragraph cause or contribute to a violation of any 
emission standard in this Subchapter or 40 CFR part 60, 61, or 63 or 
any ambient air quality standard in Section 15A NCAC 2D .0400 or 40 CFR 
part 50.'' As recognized by this provision, Federal standards in 40 CFR 
parts 60, 61, and 63, as applicable to a source, regulate source 
emissions and operation, regardless of any SSM exemption in the SIP.
    Finally, Region 4 notes that the SIP includes an overall strategy 
for bringing all areas into compliance with the NAAQS for all 
pollutants regulated by the CAA. On September 26, 2011, Region 4 
approved into the SIP significant NOX and sulfur dioxide 
(SO2) emission limitations from the North Carolina Clean 
Smokestacks Act (NCCSA).\64\ This State law became effective in 2007 
and set caps on NOX and SO2 emissions from public 
utilities operating coal-fired power plants in the State that cannot be 
met by purchasing emissions credits.\65\ The NCCSA resulted in 
permanent emission reductions that helped nonattainment areas in the 
State achieve attainment of the 1997 Annual PM2.5 NAAQS.\66\ 
Thus, even if a source could avail itself of an SSM exemption for 
certain excess emissions, its total emissions must fit within the 
utility-wide cap for the State provided under a law adopted as part of 
a comprehensive plan for improving air quality in North Carolina.
---------------------------------------------------------------------------

    \64\ See 76 FR 59250 (September 26, 2011).
    \65\ See 40 CFR 52.1781(h).
    \66\ See Approval and Promulgation of Implementation Plans and 
Designation of Areas for Air Quality Planning Purposes; North 
Carolina: Redesignation of the Hickory-Morganton-Lenoir 1997 Annual 
Fine Particulate Matter Nonattainment Area to Attainment; Proposed 
Rule, 76 FR 58210, 58217 (Sept. 20, 2011), and Approval and 
Promulgation of Implementation Plans and Designation of Areas for 
Air Quality Planning Purposes; North Carolina: Redesignation of the 
Greensboro-Winston Salem-High Point 1997 Annual Fine Particulate 
Matter Nonattainment Area to Attainment; Proposed Rule, 76 FR 59345, 
59352 (Sept. 26, 2011).
---------------------------------------------------------------------------

    Region 4 also notes that the exemption provisions in the North 
Carolina SIP are limited in scope and do not apply to sources to which 
Rules .0524, .1110 or .1111 of subchapter 2D apply. See 15A NCAC 2D 
.0535(b). These SIP provisions require that sources that are subject to 
EPA's New Source Performance Standards (NSPS) at 40 CFR part 60 or 
National Emission Standards for Hazardous Air Pollutants (NESHAP) at 40 
CFR part 61 or 63 must comply with those Federal standards rather than 
with any otherwise-applicable rule of the SIP (except where the SIP 
rule is more stringent than the Federal standards).
    Region 4 received comments challenging the June 5, 2019, NPRM's 
reliance on the generally applicable provisions, which commenters 
characterized as ``general duty'' provisions. Commenters raised 
concerns about Region 4 relying on these provisions, asserting they 
``fail to meet the level of control required by the applicable 
stringency requirements'' and that these provisions are not legally or 
practically enforceable. As discussed in Section V of this document, 
Region 4 disagrees with commenters' concerns regarding generally 
applicable provisions. Region 4 has not asserted that the numerous 
protective provisions serve to replace the applicable stringency 
requirements. Instead, these provisions provide additional assurances 
that the applicable stringency requirements will effectively ensure 
attainment and maintenance of the NAAQS, despite the fact that there 
are provisions allowing for narrow exemptions during certain periods of 
SSM. In terms of enforcing the protective provisions, many of the 
provisions identified in this document are, in fact, mandatory. For 
example, 15A NCAC 2D .0502 states: ``All sources shall be provided with 
the maximum feasible control'' (emphasis added). And 15A NCAC Code 2D 
.0501(e) instructs: ``. . . any source of air pollution shall be 
operated with such control or in such manner that the source shall not 
cause the ambient air quality standards of Section .0400 of this 
Subchapter to be exceeded at any point beyond the premises on which the 
source is located'' (emphasis added). Further, when warranted by a 
situation, EPA can bring an action to enforce these types of 
provisions.
    EPA has a statutory duty pursuant to CAA section 110(k)(3) to 
approve SIP submissions that meet all applicable

[[Page 23708]]

CAA requirements. For North Carolina, Region 4 has concluded that the 
SIP's approach to exemptions is consistent with the CAA requirement to 
protect attainment and maintenance of the NAAQS. Region 4 recognizes 
that the exemptions from emission limitations in the North Carolina SIP 
provide the State with flexibility as it develops robust approaches to 
air quality protection through a set of planning requirements. The 
numerous protective provisions are a significant justification for 
Region 4 adopting an alternative policy for the North Carolina SIP. 
Further, these provisions reflect North Carolina's reasoned judgment 
for how to best assure attainment and maintenance of the NAAQS in the 
State.

B. Director's Discretion Exemption Provisions

    In addition to the general SSM exemption issues discussed above, in 
the 2015 SSM SIP Call Action EPA also raised concerns that North 
Carolina's 15A NCAC 2D .0535(c) and 15A NCAC 2D .0535(g) are examples 
of what EPA referred to as ``director's discretion'' exemptions. Rule 
15A NCAC 2D .0535(c) lists seven criteria that the Director of NC DAQ 
will evaluate to determine whether excess emissions resulting from a 
malfunction are a violation of the given standard. In addition, rule 
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. In the 2015 SSM SIP Call Action, EPA took the 
position that these director's discretion provisions were also 
problematic because they allow air agency personnel to modify existing 
SIP requirements under certain conditions, which essentially 
constituted a variance from an otherwise applicable emission 
limitation. EPA considered director's discretion provisions to 
effectively provide for impermissible SIP revisions by allowing air 
agency personnel to make unilateral decisions on an ad hoc basis 
regarding excess emissions during SSM events and, thus, as not in 
compliance with the necessary process required for SIP revisions.\67\
---------------------------------------------------------------------------

    \67\ See 80 FR at 33977-78.
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    While acknowledging those concerns, consistent with the June 5, 
2019, NPRM, Region 4 is finalizing a finding that SSM exemptions may 
not necessarily make a SIP substantially inadequate to meet CAA 
requirements \68\ and is making a finding that the director's 
discretion SSM exemptions in the North Carolina SIP are not 
inconsistent with CAA requirements. In this action, Region 4 is 
adopting an alternative policy for North Carolina that automatic 
exemptions during periods of SSM are not inherently inconsistent with 
CAA section 110(a)(2)(A). The rationale provided above for finding that 
automatic exemptions in the North Carolina SIP do not preclude the SIP 
from meeting the CAA requirements of attainment and maintenance of the 
NAAQS under subpart A as long as the SIP, when evaluated 
comprehensively, contains a set of emission limitations, control means, 
or other means or techniques, also applies to Region 4's evaluation of 
director's discretion exemptions in the North Carolina SIP. As 
explained below, because automatic SSM exemptions are broader than 
director's discretion provisions but do not render the North Carolina 
SIP inadequate, Region 4 also finds that director's discretion 
exemptions do not render the SIP inadequate.
---------------------------------------------------------------------------

    \68\ See Texas v. EPA, 690 F.3d 670 (5th Cir. 2012); Luminant 
Generation Co. v. EPA, 675 F.3d 917 (5th Cir. 2012) (vacating and 
remanding EPA's disapproval of discretionary SIP provisions).
---------------------------------------------------------------------------

    Further, consistent with the perspective that the North Carolina 
SIP, considered as a whole, generally protects against NAAQS violations 
and that SIP provisions containing SSM exemptions may not be 
inconsistent with CAA requirements, Region 4 has determined that use of 
the director's discretion provisions in the North Carolina SIP also 
does not constitute an improper SIP revision. Given the specific 
criteria contained within them, North Carolina's director's discretion 
provisions excuse excess emissions in more limited circumstances than 
provided for by automatic exemptions. Accordingly, the same reasoning 
that supports our position that automatic exemptions in the North 
Carolina SIP may not be inconsistent with the CAA also informs our 
position that the narrower director's discretion exemption provisions 
in the North Carolina SIP that were SIP-called in the 2015 SSM SIP Call 
Action are not inconsistent with the CAA. This finding is predicated on 
a holistic view that includes consideration of all provisions in the 
North Carolina SIP. Relevant to this evaluation, as discussed above, 
the North Carolina SIP includes provisions that provide for sources to 
be operated in a manner that does not cause an exceedance or violation 
of the NAAQS, and that requirement is not displaced by the director's 
discretion exemptions. The North Carolina director's discretion 
provisions outline the specific conditions under which air agency 
personnel can make a factual decision that SSM emissions do not 
constitute a violation of the NAAQS, and that limitation is part of 
Region 4's holistic consideration of the SIP. The SIP, as federally 
approved, provides air agency personnel with the framework and 
authority to exempt certain excess emission events from being a 
violation. Because that allowance is provided for in the approved SIP, 
and the SIP provisions went through a public comment period prior to 
Region 4's final action in this document to approve them, an action 
made in accordance with these approved provisions would not constitute 
an unlawful SIP revision.
    CAA section 113 authorizes the United States to enforce, among 
other things, the requirements or prohibitions of an applicable 
implementation plan or permit. CAA section 304 authorizes citizens to 
enforce, among other things, any emission standard or limitation under 
the CAA, including applicable state implementation plan and permit 
requirements. The framework and authority contained in 15A NCAC 2D 
.0535 requires sources to make specific demonstrations and the Director 
to make specific determinations before exempting sources from 
compliance with an otherwise applicable emission limitation. 
Accordingly, and consistent with statements made by EPA when the Agency 
approved 15 NCAC 2D .0535(c) into the North Carolina SIP in 1986,\69\ 
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.
---------------------------------------------------------------------------

    \69\ See 51 FR 32073, 32074 (September 9, 1986) (EPA stated: 
``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 s 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.'').

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[[Page 23709]]

C. Withdrawal of the SIP Call for North Carolina

    As part of the 2015 SSM SIP Call Action, EPA issued CAA section 
110(k)(5) SIP calls to a number of states, including North Carolina 
regarding provisions 15A NCAC 2D .0535(c) and 15A NCAC 2D .0535(g).\70\ 
In the 2015 SSM SIP Call Action, the Agency explained that it would 
evaluate any pending SIP submission or previously approved submission 
through notice-and-comment rulemaking and, as part of that action, 
determine whether a given SIP provision is consistent with CAA 
requirements and applicable regulations.\71\ In this context, Region 4 
re-evaluated the two subject provisions in the June 5, 2019, proposed 
notice-and-comment action that Region 4 is finalizing in this document.
---------------------------------------------------------------------------

    \70\ See 80 FR at 33964.
    \71\ Id. at 33976.
---------------------------------------------------------------------------

    As discussed above, 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, based on an analysis of the multiple 
provisions contained in the North Carolina SIP that are designed to be 
protective of the NAAQS, Region 4 concludes that it is reasonable for 
the NC DAQ Director to be able to exclude qualifying periods of excess 
emissions during periods of SSM while ensuring attainment or 
maintenance of the NAAQS. A holistic review of the North Carolina SIP 
shows that there are protective provisions that ensure attainment and 
maintenance of the NAAQS even though a SIP includes SSM exemptions, and 
Region 4 believes that this result is not precluded by the D.C. Circuit 
decision in Sierra Club v. Johnson. Consistent with the alternative 
policy being adopted, as set forth above, Region 4 has reviewed the 
applicability of the SIP Call previously issued to North Carolina, 
including Region 4's specific evaluation of the State's subject SIP, 
and finds that the subject SIP provisions are not inconsistent with CAA 
requirements. Accordingly, Region 4 is changing the finding from the 
2015 SSM SIP Call Action at 80 FR 33840 that certain SIP provisions 
included in the North Carolina SIP are substantially inadequate to meet 
CAA requirements and 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).
    The alternative SSM policy is a policy statement and, thus, 
constitutes guidance within Region 4 with respect to the North Carolina 
SIP. As guidance, this does not bind states, EPA, or other parties, but 
it reflects Region 4's interpretation of the CAA requirements with 
respect to the North Carolina SIP. The evaluation of any other state's 
implementation plan provision, and that SIP provision's interaction 
with the SIP as a whole, must be done through notice-and-comment 
rulemaking.
    EPA's regulations allow EPA Regions to take actions that interpret 
the CAA in a manner inconsistent with national policy when a Region 
seeks and obtains concurrence from the relevant EPA Headquarters 
office. Pursuant to EPA's regional consistency regulations at 40 CFR 
56.5(b), the Region 4 Administrator sought and obtained concurrence 
from EPA's Office of Air and Radiation to propose an action that 
outlines an alternative policy that is inconsistent with the national 
EPA policy, most recently articulated in the 2015 SSM SIP Call Action, 
on provisions exempting emissions exceeding otherwise applicable SIP 
limitations during periods of unit startup, shutdown and malfunction at 
the discretion of the state agency and to propose action consistent 
with that alternative policy. Likewise, the Region 4 Administrator 
sought and obtained concurrence to finalize the alternative policy in 
this action. The concurrence request memorandum, signed March 19, 2020, 
is included in the public docket for this action.

IV. Region 4's Action on North Carolina's June 5, 2017, SIP Revision

    As discussed in the June 5, 2019, NPRM, on September 18, 2001, 
North Carolina submitted a new rule section regarding the control of 
NOX emissions from large stationary combustion sources to 
Region 4 for approval into its SIP.\72\ The rule section--15A NCAC 2D 
.1400 (``Nitrogen Oxides Emissions'')--contains 15A NCAC 2D .1423 
(``Large Internal Combustion Engines'') as well as other rules not 
related to this final action. On August 14, 2002, North Carolina 
submitted to Region 4 a SIP revision with changes to its Section .1400 
NOX rules, including several changes to 15A NCAC 2D .1423. 
Region 4 did not act on the August 14, 2002, submittal. However, on 
December 27, 2002, Region 4 approved the portion of North Carolina's 
September 18, 2001, SIP revision incorporating 15A NCAC 2D .1423.\73\
---------------------------------------------------------------------------

    \72\ See Rule .1402--``Applicability'' and the definition of 
``source'' in Rule .1401 for the scope of this rule section.
    \73\ See 67 FR 78987 (December 27, 2002).
---------------------------------------------------------------------------

    On June 5, 2017, North Carolina withdrew its August 14, 2002, SIP 
revision and resubmitted identical changes to 15A NCAC 2D .1423 as a 
SIP revision as well as the changes to the other rules contained in the 
original 2002 SIP revision.74 75 The State provided this 
resubmission in response to a Region 4 request for a version of the 
rule that highlights, using redline-strikethrough text, the State's 
proposed revisions to the federally approved rule. The June 5, 2017, 
SIP revision relies on the hearing record associated with the August 
14, 2002, SIP revision \76\ because the revised rule text is the same.
---------------------------------------------------------------------------

    \74\ Region 4 acted on the other rule changes through a separate 
rulemaking (83 FR 66133, December 26, 2018).
    \75\ On June 28, 2018, North Carolina supplemented its June 5, 
2017, submittal to acknowledge that Rules .1413 and .1414 are not in 
the SIP. This supplement is not relevant to this action.
    \76\ North Carolina held public hearings on May 21, 2001, and 
June 5, 2001, to accept comments on the rule changes contained in 
the August 14, 2002, SIP revision.
---------------------------------------------------------------------------

    Region 4 is approving the changes to subparagraphs (a)-(f) of 15A 
NCAC 2D .1423 provided in North Carolina's June 5, 2017, SIP revision 
for the reasons explained in the notice of proposed rulemaking. 
Regarding 15A NCAC 2D .1423(d)(1), as noted in the June 5, 2019, NPRM, 
the rule revision inserted the phrase ``and .1404 of this Section'' at 
the end so that it now provides that the owner or operator of a subject 
internal combustion engine shall determine compliance using ``a 
continuous emissions monitoring systems (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 and .1404 of this Section.'' This change ensures that the 
CEMS used to obtain compliance data must meet the applicable 
requirements specified in 15A NCAC 2D .1404 (in particular, Paragraphs 
(d)(2) and (f)(2) of 15A NCAC 2D .1404) as well as the applicable part 
60 requirements since those provisions specify additional Federal 
requirements for obtaining CEMS data. In addition, although the 
reference to ``Paragraph (g) in this Rule'' is existing federally 
approved language, Region 4 has considered its approvability in light 
of the 2015 SSM policy because paragraph (g) provides that the emission 
standards of 15A NCAC 2D .1423 (regulating large internal combustion 
engines) 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 discussed in 
Section III above, Region 4 has determined that the provisions of

[[Page 23710]]

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. 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 CAA section 
110, including CAA section 110(l). Consequently, Region 4 has 
determined, consistent with the policy outlined supra in Section III, 
that these changes to the North Carolina SIP are consistent with CAA 
requirements.

V. Responses to Comments

    Region 4 received ten supporting comments and three adverse 
comments on the proposed action. In this section, Region 4 describes in 
detail the adverse comments received and provides responses to them.

1. Comments That the Action Constitutes a Nationally-Applicable 
Rulemaking and Should be Reviewed in the D.C. Circuit

    Comment 1: Commenters state that EPA Headquarters was the driving 
force behind the preparation of the June 5, 2019, NPRM and that the 
NPRM is an attempt to revise EPA's 2015 national policy on SSM in SIPs 
in a fashion that is not reviewable by the D.C. Circuit. Other 
commenters state that the June 5, 2019, NPRM does not adequately 
justify the exception to the national policy on SSM, asserting that the 
June 5, 2019, NPRM is a ``backdoor attempt to change national policy 
through a Regional action'' with the aim of review in an individual 
Circuit Court rather than the D.C. Circuit. Commenters also assert that 
the proposed withdrawal of the North Carolina SIP Call departs from 
EPA's 2015 action and that ``this reversal effectively amends EPA's 
national SSM policy.''
    Commenters argue that if EPA were to withdraw its SSM SIP Call for 
North Carolina, review of its action should occur in the D.C. Circuit 
because such action would reverse a nationally applicable policy. 
Commenters add that any EPA refusal to find that the D.C. Circuit is 
the appropriate venue for review of EPA's SSM SIP Call is likely to 
result in different standards and methodologies applying in different 
areas of the country, thereby unlawfully and arbitrarily defeating the 
CAA's goal of ensuring uniformity of national issues, which is 
Congress's clear intent. Other commenters state that EPA recognized in 
the 2015 SSM SIP Call Action that the Agency's ``legal interpretation 
of the [CAA] concerning permissible SIP provisions to address emissions 
during SSM events'' was a ``nationally applicable'' rule and, thus, any 
petitions for review challenging aspects of EPA's nationally applicable 
SSM SIP Call or its SSM policy were required to be filed in the D.C. 
Circuit, which is where those petitions are still pending.
    Commenters also state that the June 5, 2019, NPRM is based on 
several determinations of nationwide scope or effect, and therefore EPA 
must find that any challenge to the rule is appropriate only in the 
D.C. Circuit. Commenters add that because the ``scope or effect'' of 
the Region 4 June 5, 2019, NPRM for North Carolina and the Region 6 
NPRM for Texas (84 FR 17986 (April 29, 2019)) extends across six 
judicial circuits (covering Regions 4 and 6), the NPRMs must be 
reviewed only in the D.C. Circuit. Commenters also state that EPA's 
treatment of its June 5, 2019, NPRM as Region-specific rather than of 
nationwide scope or effect is arbitrary and capricious and reviewable 
because it departs from how EPA has treated other, similar past 
actions. Commenters also state that precedent supports the conclusion 
that EPA's proposed amendment to the SSM SIP Call is ``nationally 
applicable.''
    Commenters state that although EPA is now proposing to exempt North 
Carolina from the nationally applicable SIP Call (and exempt states in 
Region 4 from the SSM SIP policy established in the final SIP Call 
rule) in a separate Federal Register document, the Agency must 
acknowledge that the SSM SIP Call and the June 5, 2019, NPRM at issue 
are part of the same overarching and ``nationally applicable 
regulation'' under 42 U.S.C. 7607(b)(1). Commenters state that the 
proposed withdrawal of North Carolina from the national SSM SIP Call 
explicitly ``departs from EPA's 2015 national policy'' and announces a 
substantive change to determining whether exemptions for SSM events in 
SIPs are approvable. Commenters also state that although the June 5, 
2019, NPRM ostensibly applies to the states in Region 4, EPA is using 
it to announce a substantial change to the CAA's SIP requirements.
    Response 1: Comments received regarding Region 6's April 29, 2019, 
notice of proposed rulemaking concerning affirmative defense provisions 
in the Texas SIP are not within the scope of this rulemaking, and 
Region 4 is not providing a response to comments regarding that action. 
Comments regarding any subsequent and separate actions by Region 4 are 
also speculative and not within the scope of this rulemaking.
    This is a regional action to approve a SIP submission from a single 
state in Region 4 and to withdraw the SSM SIP Call that was issued for 
North Carolina based on an alternative SSM policy that is being adopted 
and applied by Region 4 only with regard to the North Carolina SIP; the 
commenter provides no factual basis for the claim that Region 4 is 
speaking on behalf of EPA Headquarters in this action. EPA Headquarters 
and Regional Offices routinely collaborate on rulemaking activities, 
and the nature of the collaborative relationship varies depending on 
the circumstances of the specific action involved. EPA Headquarters 
staff may be involved in drafting complex regional actions, including 
proposed and final rulemakings where EPA acts on SIP submissions under 
CAA section 110(k), as appropriate. However, as explained below in this 
response, the level of involvement by different EPA offices is not an 
appropriate inquiry for determining which court would review a final 
action. As described in Section III, the alternative policy on SSM 
adopted in this action applies only to Region 4's evaluation of the 
North Carolina SIP and does not change or alter EPA's national policy 
on SSM from the June 12, 2015, action at 80 FR 33840.
    Recognizing that Congress intended the Federal-state partnership to 
serve as a cornerstone of the SIP development process under the CAA, 
the latitude typically afforded to state air agencies as they develop 
SIPs to address air pollution prevention in their states is one of the 
bases for this action. Section III of both the proposed action and this 
final action provides a comprehensive explanation for Region's 4 bases 
for adopting the alternative policy for North Carolina. Section III of 
this final action then applies that alternative policy to the specific 
facts of the North Carolina SIP.
    The comments stating that this action is a ``backdoor attempt to 
change national policy through Regional action'' or that this action 
establishes a new de facto national policy overstate and misunderstand 
the scope of the present action. Region 4 is not establishing a new 
national policy; rather Region 4 is taking action on a specific 
provision submitted to EPA as a revision of the North Carolina SIP and 
evaluating the adequacy of specific

[[Page 23711]]

North Carolina SIP provisions to meet CAA requirements.
    Region 4 does not agree with commenters' assertion that this action 
is a reversal of EPA's national SSM policy because the alternative 
policy adopted by Region 4 on SSM exemptions is specific to Region 4's 
evaluation of the North Carolina SIP--the policy is not adopted or 
applied to any other SIP in Region 4 and does not change or alter the 
national policy on SSM established in the 2015 SSM SIP Action. This 
action is limited to the North Carolina SIP. Region 4 is simply 
reexamining the 2015 SSM SIP Action as it applies to the North Carolina 
SIP, including the North Carolina SIP provisions that were the subject 
of EPA's finding of substantial inadequacy in that prior action. Region 
4 is also reevaluating the interpretation of the Sierra Club decision 
and determining that it is not necessary to extend the reach of the 
Sierra Club decision to the particular North Carolina SIP provisions at 
issue in this action.
    As the D.C. Circuit has recently explained, ``[t]he court need look 
only to the face of the agency action, not its practical effects, to 
determine whether an action is nationally applicable.'' \77\ On its 
face, this action is locally applicable because it applies to only a 
single state, North Carolina (withdrawing the SIP Call issued to North 
Carolina in 2015 and approving the specific North Carolina SIP 
provisions in the revision submitted by the State on June 5, 2017). 
This action has immediate or legal effect only for and within North 
Carolina. If EPA were to rely on the statutory interpretation set forth 
in this action in another potential future final Agency action, the 
statutory interpretation would be subject to judicial review upon 
challenge of that later action.
---------------------------------------------------------------------------

    \77\ Sierra Club v. EPA, 926 F.3d 844, 849 (D.C. Cir. 2019) 
(citing Dalton Trucking, 808 F.3d 875, 881 (D.C. Cir. 2015) and Am. 
Road & Transp. Builders Ass'n v. EPA, 705 F.3d 453, 456 (D.C. Cir. 
2013)).
---------------------------------------------------------------------------

    Moreover, EPA's regulations at 40 CFR part 56 contemplate and 
establish a process for regional deviation from national policy. Region 
4 followed that process and received concurrence from the appropriate 
EPA headquarters office for both the proposed action and this final 
action. The memoranda documenting this process are available in the 
docket for this action. We disagree with commenters' contention that 
this action undermines a goal of ensuring uniformity of national issues 
of the CAA. We assume that the commenter is referencing section 
301(a)(2), which requires EPA to promulgate regulations establishing 
general applicable procedures and policies for regions that are 
designed, among other things, to ``assure fairness and uniformity in 
the criteria, procedures, and policies applied.'' Region 4 followed the 
process to deviate from national policy set forth in 40 CFR part 56, 
the regulations that EPA promulgated in accordance with CAA section 
301(a)(2). Commenters' concern regarding the Agency's general process 
for regional deviation from national policy is beyond the scope of this 
action.
    Under the venue provision of the CAA, an EPA action ``which is 
locally or regionally applicable'' may be filed ``only in the United 
States Court of Appeals'' covering that area.\78\ The only exception to 
this mandate is where the Administrator expressly finds that the 
locally or regionally applicable action is based on a determination of 
nationwide scope or effect and publishes such a finding. The 
requirement that the Administrator find and publish that an otherwise 
locally or regionally applicable action is based on a determination of 
nationwide scope or effect is an express statutory requirement for 
application of this venue exception; this exception has not been and is 
not being invoked by EPA in this action. Absent an express statement--
and publication--that such a finding has been made, thus invoking the 
venue exception, there can be no application of that exception.\79\ CAA 
section 307 expressly provides the Agency full discretion to make its 
own determination of whether to exercise an exception to a 
Congressionally-dictated venue rule.\80\ Even assuming that a court 
could review the lack of such a finding, and lack of publication of 
such a finding, in this final action under the Administrative Procedure 
Act's arbitrary and capricious standard, the absence of invocation of 
the exception is not unreasonable in this case. Commenters assert that 
numerous aspects of Region 4's action, including its decision to seek 
concurrence to propose an action inconsistent with national policy, 
somehow constitutes an admission that such action is based on a 
determination of nationwide scope or effect. Commenters are not clear 
on how or why taking the step necessary to deviate from nationwide 
policy somehow transforms that deviation into nationwide policy. Region 
4 lacks the authority to issue a policy beyond the states included in 
the Region. In any case, Region 4 states throughout this document that 
this action, and the CAA interpretation it is based upon, only applies 
in North Carolina and does not alter EPA's national policy.\81\
---------------------------------------------------------------------------

    \78\ See 42 U.S.C. 7607(b)(1) (emphasis added).
    \79\ See, e.g., Lion Oil v. EPA, 792 F.3d 978, 984 n.1 (8th Cir. 
2015) (even where EPA, unlike here, made the necessary finding, the 
court found no need to decide application of the venue exception 
absent publication of that finding); Texas v. EPA, 829 F.3d 405, 419 
(5th Cir. 2016) (``This finding is an independent, post hoc, 
conclusion by the agency about the nature of the determinations; the 
finding is not, itself, the determination.''); Dalton Trucking v. 
EPA, 808 F.3d 875 (D.C. Cir. 2015).
    \80\ See Texas v. EPA, 829 F.3d at 419-20 (the venue exception 
``gives the Administrator the discretion to move venue to the D.C. 
Circuit by publishing a finding declaring the Administrator's belief 
that the action is based on a determination of nationwide scope or 
effect.'') (emphasis added).
    \81\ See Am. Road & Transp. Builders Ass'n v. EPA, 705 F.3d 453, 
456 (D.C. Cir. 2013) (holding that venue for review of EPA's 
approval of revisions to California's SIP lay in the Ninth Circuit 
because the approval only applied to projects within California, 
even if the SIP could set a precedent for future proceedings).
---------------------------------------------------------------------------

    The commenters argue that it is appropriate for EPA to find and 
publish a finding that an action is based on a determination of 
nationwide scope or effect where a regionally applicable action 
encompasses multiple judicial circuits. Region 4 does not take a 
position on this question here, nor does it need to do so, because as 
explained earlier in this document, this final action is limited to 
North Carolina, and thus only a single judicial circuit. Although at 
proposal Region 4 was contemplating a regionwide policy on SSM 
exemption provisions in SIPs, the Region has decided to limit the 
deviation from national policy to North Carolina. The final action 
being taken herein is limited in scope to approval of a North Carolina 
SIP revision and withdrawal of the SIP Call issued to North Carolina.
    Region 4 does not agree with commenters' assertion that EPA has 
previously directed review of SIP Calls to the D.C. Circuit. We note 
that EPA consolidated a single announcement of national policy and 
issued 36 individual SIP Calls through a single document in the 2015 
SSM SIP Action. However, at other times, individual regions have issued 
SIP Calls, which were subsequently reviewed in regional circuits. In 
2011, for example, EPA Region 8 made a finding that the Utah SIP was 
substantially inadequate to meet CAA requirements. On that basis, EPA 
Region 8 issued a SIP Call for Utah, requiring the state to revise its 
SIP to change an unavoidable breakdown rule, which exempted emissions 
during unavoidable breakdowns from compliance with emission 
limitations.\82\ This SIP Call was subsequently reviewed in and upheld 
by the U.S.

[[Page 23712]]

Court of Appeals for the Tenth Circuit.\83\ Similarly, EPA Region 8 
made a finding that the Montana SIP was substantially inadequate to 
attain and maintain the SO2 NAAQS and issued a call for 
Montana to submit a SIP revision.\84\ That SIP Call and related actions 
were subsequently reviewed in and upheld by the U.S. Court of Appeals 
for the Ninth Circuit.\85\
---------------------------------------------------------------------------

    \82\ See 76 FR 21639 (April 18, 2011).
    \83\ US Magnesium v. EPA, 690 F.3d 1157 (10th Cir. 2012).
    \84\ See 58 FR 41430 (Aug. 4, 1993).
    \85\ Mont. Sulphur & Chem. Co. v. EPA, 666 F.3d 1174 (9th Cir. 
2012).
---------------------------------------------------------------------------

2. Comments That EPA Lacks the Statutory Authority To Undertake the 
Action

    Comment 2: Commenters state that, faced with plain statutory 
language in section 302(k) and a statutory structure and cross-
references in section 110, EPA may not invent statutory authority where 
none exists, nor adopt regulations lacking statutory authority, merely 
because EPA believes its approach to be better policy. Commenters state 
that agencies need especially clear congressional delegations of 
authority to create regulatory exemptions and that the Region 4 (and 
Region 6) ``alternative interpretations'' amount to contradictory, 
unlawful statutory readings that advance policy preferences. Commenters 
add that those policy preferences furnish EPA with no statutory 
authority to withdraw the 2015 SSM SIP Call or to approve SIPs or 
submissions inconsistent with the SIP Call, plain statutory language, 
and the Sierra Club SSM decision.
    Commenters state that EPA must reject at least a portion of this 
submittal as substantially inadequate because it includes a prohibited 
automatic exemption for SSM events at 15A NCAC 2D .1423(g) (``The 
emission standards of this Rule shall not apply to . . . start-up and 
shut-down periods and periods of malfunction . . . .'').
    Commenters state that by proposing to find North Carolina 
provisions 15A NCAC 2D .0535(c) and .0535(g) are not substantially 
inadequate to meet CAA requirements, EPA proposes an unlawful act that 
is beyond the scope of the SIP revision submitted to Region 4. 
Commenters allege that because North Carolina's June 5, 2017, 
submission to Region 4 makes no revision to its SSM exemptions or any 
mention of 15A NCAC 2D .0535, this action would amount to an EPA-
initiated revision of the SIP, which, in addition to EPA's self-
initiated change in regional policy, is not among the actions EPA may 
take when presented with a SIP revision. Commenters add that even if 
EPA could initiate such an action, EPA would still proceed unlawfully 
by purporting to act on a submittal that does meet applicable 
completeness requirements because the Agency has received no submittal 
or requested revision on to act on 15A NCAC 2D .0535(c) and .0535(g) 
and that the submission received does not include 15A NCAC 2D .1423(g) 
among the revised subsections of 15A NCAC 2D .1423 submitted for 
review. Commenters also contend that part 51 requires that the record 
for a SIP revision submittal contain a letter ``from the Governor or 
his designee, requesting EPA approval of the plan or revision'' \86\ 
but that North Carolina's submission is not signed by the governor, and 
its signatory, Michael Abraczinskas, gives no indication of acting at 
the Governor's request.
---------------------------------------------------------------------------

    \86\ See 40 CFR part 51, appendix V, 2.1(a).
---------------------------------------------------------------------------

    Response 2: Rather than inventing statutory authority as 
contemplated by the comment, after conducting a searching and thorough 
evaluation of the North Carolina SIP and relevant statutory and 
regulatory framework, Region 4 is offering an alternative 
interpretation to the national policy on SSM outlined in the 2015 
action. The U.S. Supreme Court has expressly provided that 
administrative agencies may change an interpretation.\87\ Consistent 
with the U.S. Supreme Court's decision, in its June 5, 2019, NPRM 
Region 4 acknowledged the Agency's prior position, provided statutory 
authority for the new interpretation, explained its rationale for the 
change and explained why the action taken in this document is the 
better policy in this circumstance.\88\ Commenters' disagreement with 
the interpretation does not preclude Region 4 from having authority to 
change its policy when it has met the required conditions.
---------------------------------------------------------------------------

    \87\ See FCC v. Fox Television Stations, Inc., 556 U.S. 502 
(2009).
    \88\ Id. at 515.
---------------------------------------------------------------------------

    Region 4 disagrees with commenters' contention that the plain 
statutory language of CAA section 302(k) and a statutory structure and 
cross-references in section 110 preclude the alternative policy 
adopted. Acknowledging that the Agency took a different approach in the 
2015 SSM SIP Call Action, for the reasons articulated in Section III of 
this final action Region 4 has adopted an alternative policy for the 
North Carolina SIP. It is reasonable to interpret the 302(k) definition 
of ``emission limitation'' and ``emission standard'' as meaning ``a 
requirement . . . which limits the quantity, rate, or concentration of 
emissions of air pollutants on a continuous basis'' and account for the 
fact that there are numerous source types for which a single limitation 
cannot apply at all times for technical reasons. In Sierra Club, the 
Court agreed that the Act does not require a single limitation apply at 
all times but that some section 112-compliant standard must be 
applicable at all times.\89\ In response to the Sierra Club decision's 
directive that a single standard need not apply continuously, for many 
of the NESHAP, EPA has established numerical emission limits that apply 
during full operation but that would be either impractical or 
impossible to meet during periods of startup and shutdown and therefore 
also established other emission limitations, such as work practice 
standards, to apply during periods of startup and shutdown.
---------------------------------------------------------------------------

    \89\ See 551 F.3d at 1021.
---------------------------------------------------------------------------

    Under CAA section 110(a)(2)(A), states are tasked with adopting 
``emission limitations and other control measures, means, or techniques 
. . . as may be necessary or appropriate to meet the applicable 
requirements of this Act'' (emphasis added). States have generally 
adopted numerical emission limits that apply to sources during full 
operational mode. However, since some source types may not be capable 
of complying with such limits during periods of startup and shutdown, 
North Carolina has provided for exclusions from the numerical limits 
during those events and adopted other mechanisms for minimizing source 
emissions instead. As discussed in Section III of this final action, 
the North Carolina SIP contains myriad provisions that generally 
provide for attainment and maintenance of the NAAQS. Region 4's 
evaluation of the North Carolina SIP contributed to determining that it 
is appropriate to adopt an alternative policy for North Carolina for 
SSM exemption provisions in SIPs. As stated in the June 5, 2019, NPRM 
and in this final action, these other mechanisms may include a 
combination of general duty provisions, work practice standards, best 
management practices, or alternative emission limits, as well as 
entirely separate provisions, such as minor source and major source new 
source review provisions regulating construction or modification of 
stationary sources, that also effectively limit emissions of NAAQS 
pollutants at all times, including during any SSM events. For the 
reasons articulated in Section III of this document, Region 4 disagrees 
that the automatic exemption for SSM events at 15A NCAC 2D

[[Page 23713]]

.1423(g) impacts approvability of the SIP revisions in light of the 
protections afforded by the North Carolina SIP as a whole.
    The withdrawal of the SIP Call cannot be an unlawful revision to 
the North Carolina SIP because this withdrawal does not revise the SIP. 
In this action, Region 4 is not taking action to approve 15A NCAC 2D 
.0535(c) and .0535(g) into the North Carolina SIP. These provisions 
were previously approved by EPA into the North Carolina SIP \90\ and 
have not been removed from the North Carolina SIP. In this action, 
Region 4 is making a finding that these two provisions are not 
substantially inadequate to meet CAA requirements and thus withdrawing 
the SIP Call previously issued to North Carolina that directed the 
state to provide a SIP revision to address the substantial inadequacy 
caused by these provisions. We acknowledge that Region 4's finding with 
respect to the adequacy of 15A NCAC 2D .0535(c) and .0535(g) has 
changed, but this change, in and of itself, does not constitute a 
revision of the SIP. On the basis of this change in interpretation for 
the North Carolina SIP, Region 4 is approving a revision to 15A NCAC 2D 
.1423 submitted by the state of North Carolina on June 5, 2017, under 
CAA 110(k)(3). The SIP revision was initiated by the North Carolina 
Division of Air Quality, and therefore this action cannot be construed 
as an ``EPA-initiated revision of the SIP.''
---------------------------------------------------------------------------

    \90\ See 51 FR 32073 (September 9, 1986) and 62 FR 41277 (August 
1, 1997), respectively.
---------------------------------------------------------------------------

    As stated in NC DAQ's June 5, 2017, letter, the State provided 
redline/strikeout versions of six rules for the purpose of 
administrative review at EPA's request. The letter stated that it had 
enclosed ``the revised text for rules .1401, .1403, .1406, .1413, 
.1414, and .1423 that we are requesting your review and approval.'' 
Region 4 agrees with the commenter that, while the submittal includes 
the entire text of 15A NCAC 2D .1423, paragraph (g) is not among the 
revised subsections of 15A NCAC 2D .1423. However, as indicated in the 
NPRM, 15A NCAC 2D .1423(d), which is being revised, includes a 
meaningful reference to .1423(g).\91\ Therefore, because paragraph (d) 
is, in part, dependent on paragraph (g), it was appropriate for Region 
4 to assess the adequacy of paragraph (g) in order to assess whether 
the revisions to paragraph (d) were approvable under the CAA. Region 
4's resultant review of North Carolina's SIP, including the SIP-called 
provisions, 2D .0535(c) and .0535(g), led to the proposal of an SSM 
policy for North Carolina that is an alternative to the national SSM 
policy but that is still consistent with the requirements of the CAA.
---------------------------------------------------------------------------

    \91\ See 84 FR at 26040 (``Rule .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.' . . . Paragraph 
(g) of Rule .1423 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.' '') (emphasis added).
---------------------------------------------------------------------------

    In addition, Region 4 disagrees with the comment that NC DAQ's June 
5, 2017, submittal fails to meet the applicable completeness 
requirements prescribed under appendix V. Paragraph 1.2 of appendix V 
to part 51 provides that if a completeness determination is not made by 
six months from receipt of a submittal (which EPA did not for NC DAQ's 
June 5, 2017, submittal), the submittal shall be deemed complete by 
operation of law on the date six months from receipt. Thus, NC DAQ's 
June 5, 2017, has been deemed complete, and EPA must act upon it in 
accordance with CAA section 110(k)(2).
    Commenters also misinterpret part 51, appendix V, 2.1(a) to require 
the signatory on the submittal to be acting at the Governor's request. 
This provision requires that a SIP revision submittal include a letter 
``from the Governor or his designee, requesting EPA approval of the 
plan or revision thereof . . . .'' Thus, the cover letter on a SIP 
revision request submitted to EPA must be signed by either the Governor 
or the Governor's designee, and a designee is not required to be acting 
at the Governor's request on a particular submittal. In this case, the 
Director of NC DAQ has been delegated authority to administer the 
regulatory provisions of state law relating to air pollution 
control.\92\
---------------------------------------------------------------------------

    \92\ See letter from the Secretary of the North Carolina 
Department of Environment and Natural Resources to the Director, NC 
DAQ, June 28, 2010, included in the docket for this rulemaking.
---------------------------------------------------------------------------

3. Comments That EPA Has Not Sufficiently Explained Why the 
Interpretation of ``emission limitation'' Under Section 110 Might Be 
Different From the Interpretation Under Section 112

    Comment 3: Commenters assert that EPA should articulate what 
meaning it gives ``emission limitation'' under CAA section 110 versus 
CAA section 112 and why that alternative interpretation is reasonable. 
Commenters suggest that EPA could explain relevant terminology such as 
``other control measures, means, or techniques'' in lieu of referring 
to the rules at issue as ``emission limitations,'' and point out that 
the CAA does not require those other measures to apply continuously as 
it does emission limitations.
    Commenters state that EPA does not explain how continuous emission 
limits are not applicable to CAA section 110 or, therefore, why the 
decision related to CAA section 112 in Sierra Club is not applicable to 
SIPs. The commenters add that EPA's analysis regarding CAA section 110 
versus CAA section 112 and the Sierra Club decision in the June 5, 
2019, NPRM restates arguments that were discussed and rejected in the 
2015 SSM SIP Call Action.
    Other commenters state that EPA is wrong to propose that it may be 
reasonable to interpret the concept of continuous ``emission 
limitations'' in a SIP to not be focused on implementation of each, 
individual limit, but rather whether the approved SIP, as a whole, 
operates continuously to ensure attainment and maintenance of the 
NAAQS. Commenters argue that the CAA section 302(k)'s definition of 
``emission limitation'' and ``emission standard'' applies to those 
terms in section 110 SIPs and that the definitions in 42 U.S.C. 7602 
are preceded by statutory language noting that the ensuing definitions 
apply ``[w]hen used in this chapter,'' that is, across the CAA. 
Commenters add that EPA may not construe a statute in a way that 
completely nullifies textually applicable provisions meant to limit its 
discretion and that the June 5, 2019, NPRM completely ignores statutory 
language and the limit on EPA's discretion. Commenters also state that 
while EPA correctly notes that ``the court did not make any statement 
explicitly applying its holding beyond CAA section 112,'' it did not 
need to because, as relevant here, Sierra Club focused on section 
302(k), not section 112.
    Response 3: Region 4 acknowledges that commenters disagree with the 
interpretation offered in the June 5, 2019, NPRM and finalized in the 
current action, but the proposed action and this final action contain 
extensive explanation supporting the alternative interpretation 
regarding the interplay of CAA section 302(k) and CAA section 110 and 
why this alternative interpretation is reasonable for the North 
Carolina SIP. Region 4 directs commenters to Section III of the June 5, 
2019, NPRM and this final action for a thorough explanation of its 
interpretation of CAA section 302(k) in the contexts of CAA section 110 
compared to CAA section 112.

[[Page 23714]]

    As discussed in Section III of the proposed action and of this 
final action, Region 4 focused on the flexibility given under section 
110, i.e., 110(a)(2)(A), in contrast to section 112. Region 4 noted 
that the definition of ``emission limitation'' at CAA section 302(k), 
when read in the 110 context, could provide flexibility to states for 
providing exemptions at times ``when it is not practicable or necessary 
for such limits to apply, so long as the SIP contains other provisions 
that remain in effect and ensure the NAAQS are protected.'' \93\ In the 
context of CAA section 110, it is reasonable to interpret the term 
``emission limitation'' differently from how that term is interpreted 
in CAA section 112 because of the distinct purposes and requirements of 
the two provisions. CAA section 110 focuses on the attainment and the 
maintenance of the NAAQS, which is achieved through numerous 
provisions, adopted by the state and applied to sources throughout the 
state (or relevant jurisdiction), working together to meet the 
statutory requirements. CAA section 112, however, requires an exacting 
analysis to establish requirements for the regulation of hazardous air 
pollutants (HAP) from specific source categories. CAA section 112 
standards only address the regulation of HAP emissions from each 
respective source category; they do not address attainment or 
maintenance of the NAAQS, nor do they have the benefit of backstops and 
overlapping, generally applicable provisions. Further, Region 4 
evaluates the SIP comprehensively to determine whether the SIP as a 
whole meets the requirement of attaining or maintaining the NAAQS under 
subpart A.\94\
---------------------------------------------------------------------------

    \93\ See 84 FR at 26035.
    \94\ See 84 FR at 26035.
---------------------------------------------------------------------------

    The North Carolina SIP includes general SIP provisions and 
overlapping planning requirements. In Section IV of the June 5, 2019, 
NPRM, as reiterated in Section III of this final action, Region 4 has 
identified generally protective provisions (at 15A NCAC 2D .0501(e), 2D 
.0510(a), 2D .0511(a), and 2D .0512) as well as specific emission 
limitations of the North Carolina SIP where appropriate.
    Commenters incorrectly assert that the June 5, 2019, NPRM fails to 
explain why continuous emission limitations are not applicable to CAA 
section 110 and the rationale for distinguishing the Sierra Club 
decision. A thorough explanation of Region 4's interpretation of CAA 
section 302(k) in the context of evaluating the North Carolina SIP 
pursuant to CAA section 110(a)(2)(A), including a discussion of why the 
Sierra Club decision is not applicable in the Section 110 context, is 
provided in the June 5, 2019, NPRM at 84 FR at 26034-36, and Region 4 
refers the commenter to that explanation, together with the discussion 
of this issue included in Section III of this final action.
    Regarding commenters' statement that the arguments made in support 
of the alternative policy were explicitly discussed and rejected in the 
final 2015 SSM SIP Call Action, Region 4 is unable to respond because 
commenters did not specifically identify which arguments they are 
referencing. In the 2015 SSM SIP Call Action, EPA stated that Sierra 
Club supported the policy position outlined in that document, but EPA 
did not say that the Sierra Club decision compelled that policy 
position. In fact, the 2015 SSM SIP Call Action acknowledged that the 
``decision turned, in part, on the specific provisions of section 
112.'' \95\ As explained above in the response to Comment 2, the U.S. 
Supreme Court has expressly provided that administrative agencies may 
change an interpretation.\96\ Consistent with the U.S. Supreme Court's 
decision, in its June 5, 2019, NPRM Region 4 acknowledged the Agency's 
prior position, provided statutory authority for the new 
interpretation, explained its rationale for the change, and explained 
why it believes the new interpretation is the better policy in this 
circumstance.\97\ Commenters' disagreement with the interpretation does 
not preclude Region 4 from having authority to change its policy when 
it has met the required conditions.
---------------------------------------------------------------------------

    \95\ See 80 FR at 33893.
    \96\ See Fox, 556 U.S. 502.
    \97\ Id. at 515.
---------------------------------------------------------------------------

    Region 4 acknowledges that CAA section 110(a)(2)(A) uses the term 
``emission limitation,'' however given how EPA and state agencies have 
worked cooperatively to implement CAA section 110, Region 4 does not 
concede that the term must be interpreted exactly the same in the 
context of CAA section 110 as it was interpreted by the D.C. Circuit in 
the context of CAA section 112. A thorough rationale for the 
alternative interpretation is included in Section III of the proposed 
action and this final action.
    Although CAA section 302(k) instructs that an emission limitation 
limits the quantity, rate, or concentration of emissions of air 
pollutants on a continuous basis, emission limitations are merely one 
of numerous measures that can be used by a state to limit emissions 
pursuant to CAA section 110(a)(2)(A). While a director may exempt 
excess emissions which occurred during a period of startup, shutdown 
and malfunction, assuming an appropriate showing has been made by the 
source, other ``control measures, means and techniques,'' and 
potentially other emission limitations, will continue to apply to the 
source.
    Region 4 acknowledges the comment that the presumption of 
consistent usage dictates that a word or phrase is presumed to bear the 
same meaning throughout a text; a material variation in terms suggests 
a variation in meaning. Importantly, however, the presumption should be 
applied pragmatically, and relevant texts indicate that ``this canon is 
particularly defeasible by context.'' \98\ It is appropriate to rely on 
the Duke Energy decision for the proposition that the rule of statutory 
interpretation calling for words to be defined consistently can be 
overcome, depending on context.\99\ Here, that context is particularly 
relevant given the different structure and purpose between CAA sections 
110 and 112, as described in more detail in Section III of the proposed 
action and of this final action.
---------------------------------------------------------------------------

    \98\ Antonin Scalia & Bryan A. Garner, Reading Law: The 
Interpretation of Legal Texts 171 (Thompson/West) (2012).
    \99\ See Valerie C. Brannon, Cong. Research Serv., R45153, 
Statutory Interpretation: Theories, Tools, and Trends 23 (April 5, 
2018) (quoting Envtl. Def. v. Duke Energy Corp., 549 U.S. 561, 574 
(2007)) (``A given term in the same statute may take on distinct 
characters from association with distinct statutory objects calling 
for different implementation strategies'').
---------------------------------------------------------------------------

    Contrary to commenters' assertion, neither CAA section 110(a)(2)(A) 
or 302(k) is ``nullif[ied]'' by Region 4's interpretation in the 
context of this SIP action. Rather, Region 4 offers an alternative 
interpretation of both provisions, which focuses on the purpose of 
SIPs, consistent with CAA section 110, and the concept proffered by CAA 
section 302(k), as interpreted by the D.C. Circuit that some standard, 
but not necessarily the same standard, apply at all times.\100\
---------------------------------------------------------------------------

    \100\ See Sierra Club, 551 F.3d at 1021.
---------------------------------------------------------------------------

    Commenters acknowledge that in the Sierra Club decision, ``the 
court did not make any statement explicitly applying its holding beyond 
CAA section 112.'' However, Region 4 disagrees with the commenters' 
characterization that Sierra Club must apply beyond CAA section 112, 
since the court consistently referred to ``112-compliant standards'' 
\101\ and the requirements that ``sources regulated under section 112 
meet the strictest standards.'' \102\ It is fair

[[Page 23715]]

for Region 4 to give weight to the language used by the court and to 
not expand the decision in this context.
---------------------------------------------------------------------------

    \101\ Id. at 1027.
    \102\ Id. at 1028.
---------------------------------------------------------------------------

4. Comments That the 302(k) Definition of ``Emission Limits'' and 
``Emission Standards'' Requires Continuous Emission Limits and That the 
North Carolina SIP Does not Provide Protections That are Equally 
Stringent to Continuously Applicable Emission Limits

    Comment 4: Commenters generally argue that EPA's June 5, 2019, NPRM 
contradicts CAA section 302(k) by allowing ``emission limitations'' to 
include automatic and discretionary exemptions for SSM events, 
violating the Act's requirement that emission limitations be 
``continuous.'' Commenters note that EPA has read CAA section 302(k) to 
exclude SSM exemptions from SIPs ``since at least 1982.'' \103\ 
Commenters, citing Sierra Club, also state that the D.C. Circuit has 
held, in a case interpreting the section 302(k) definition of 
``emission limitations'' as it appears in the Act's section 112 MACT 
standards, that an emission limitation does not apply on a ``continuous 
basis'' when it includes SSM exemptions.
---------------------------------------------------------------------------

    \103\ See 80 FR 33941/1.
---------------------------------------------------------------------------

    Commenters claim that by using a singular, indefinite article--``a 
requirement''--Congress also makes clear that ``emissions limitation'' 
must be a discrete, ongoing requirement, not a ``broad range of 
measures . . . targeted toward attainment and maintenance'' of NAAQS 
and that CAA 302(k)'s terms apply just as much to emission standards or 
limitations a state establishes as part of its SIP as to those EPA 
establishes.
    Commenters state that automatic and discretionary exemptions 
violate the bedrock principles of the Act that SIPs must contain 
``enforceable emission limitations'' (CAA section 110(a)(2)(A)), which 
must apply on a ``continuous basis'' (CAA section 302(k)). Commenters 
add that Congress gave states no authority to relax emission standards 
on a temporal basis. Commenters also quote the Court in U.S. Sugar 
Corp. v. EPA as stating, ``exempt[ing] periods of malfunction entirely 
from the application of the emissions standards . . . is [not] 
consistent with the Agency's enabling statutes,'' \104\ and ``EPA had 
no option to exclude these unpredictable periods.'' \105\
---------------------------------------------------------------------------

    \104\ No. 11-1108, 2016 WL 4056404, at *14 (D.C. Cir. July 29, 
2016).
    \105\ Id. at *15.
---------------------------------------------------------------------------

    Commenters state that even if there are instances where automatic 
exemptions from emission limits for SSM events in a SIP do not preclude 
attainment and maintenance of the NAAQS, EPA must issue a SIP call if a 
state's SIP is substantially inadequate to maintain the NAAQS or 
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

[[Page 23716]]

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,

[[Page 23717]]

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

[[Page 23718]]

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

[[Page 23719]]

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).

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

[[Page 23720]]

    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

[[Page 23721]]

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\
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    \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.
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    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\
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    \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.

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[[Page 23722]]

    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\
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    \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).
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    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

[[Page 23723]]

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

[[Page 23724]]

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\
---------------------------------------------------------------------------

    \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.
---------------------------------------------------------------------------

    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).
---------------------------------------------------------------------------

    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

[[Page 23725]]

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.
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    \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

[[Page 23726]]

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

[[Page 23727]]

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

[[Page 23728]]

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\
---------------------------------------------------------------------------

    \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

[[Page 23729]]

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\
---------------------------------------------------------------------------

    \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

[[Page 23730]]

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