[Federal Register Volume 81, Number 110 (Wednesday, June 8, 2016)]
[Proposed Rules]
[Pages 36842-36848]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-13606]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2016-0247; FRL-9947-40-Region 4]


Air Plan Approval; South Carolina; Prong 4--2008 Ozone, 2010 NO2, 
SO2, and 2012 PM2.5

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
conditionally approve the portions of revisions to the South Carolina 
State Implementation Plan (SIP), submitted by the South Carolina 
Department of Health and Environmental Control (SC DHEC), addressing 
the Clean Air Act (CAA or Act) visibility transport (prong 4) 
infrastructure SIP requirements for the 2008 8-hour Ozone, 2010 1-hour 
Nitrogen Dioxide (NO2), 2010 1-hour Sulfur Dioxide 
(SO2), and 2012 annual Fine Particulate Matter 
(PM2.5) National Ambient Air Quality Standards (NAAQS). The 
CAA requires that each state adopt and submit a SIP for the 
implementation, maintenance, and enforcement of each NAAQS promulgated 
by EPA, commonly referred to as an ``infrastructure SIP.'' 
Specifically, EPA is proposing to conditionally approve the prong 4 
portions of South Carolina's July 17, 2008, 8-hour Ozone infrastructure 
SIP submission; April 30, 2014, 2010 1-hour NO2 
infrastructure SIP submission; May 8, 2014, 2010 1-hour SO2 
infrastructure SIP submission; and December 18, 2015, 2012 annual 
PM2.5 infrastructure SIP submission. All other applicable 
infrastructure requirements for these SIP submissions have been or will 
be addressed in separate rulemakings.

DATES: Comments must be received on or before July 8, 2016.

ADDRESSES: Submit your comments, identified by Docket ID No EPA-R04-
OAR-2016-0247 at http://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. EPA may publish any comment 
received to its public docket. Do not submit electronically any 
information you consider to be Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e. on the web, cloud, or other file sharing 
system). For additional submission methods, the full EPA public comment 
policy, information about CBI or multimedia submissions, and general 
guidance on making effective comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Sean Lakeman of the Air Regulatory 
Management Section, Air Planning and Implementation Branch, Air, 
Pesticides and Toxics Management Division, U.S. Environmental 
Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia 
30303-8960. Mr. Lakeman can be reached by telephone at (404) 562-9043 
or via electronic mail at [email protected].

SUPPLEMENTARY INFORMATION:

I. Background

    By statute, SIPs meeting the requirements of sections 110(a)(1) and 
(2) of the CAA are to be submitted by states within three years after 
promulgation of a new or revised NAAQS to provide for the 
implementation, maintenance, and enforcement of the new or revised 
NAAQS. EPA has historically referred to these SIP submissions made for 
the purpose of satisfying the requirements of sections 110(a)(1) and 
110(a)(2) as ``infrastructure SIP'' submissions. Sections 110(a)(1) and 
(2) require states to address basic SIP elements such as the 
requirements for monitoring, basic program requirements, and legal

[[Page 36843]]

authority that are designed to assure attainment and maintenance of the 
newly established or revised NAAQS. More specifically, section 
110(a)(1) provides the procedural and timing requirements for 
infrastructure SIPs. Section 110(a)(2) lists specific elements that 
states must meet for the infrastructure SIP requirements related to a 
newly established or revised NAAQS. The contents of an infrastructure 
SIP submission may vary depending upon the data and analytical tools 
available to the state, as well as the provisions already contained in 
the state's implementation plan at the time in which the state develops 
and submits the submission for a new or revised NAAQS.
    Section 110(a)(2)(D) has two components: 110(a)(2)(D)(i) and 
110(a)(2)(D)(ii). Section 110(a)(2)(D)(i) includes four distinct 
components, commonly referred to as ``prongs,'' that must be addressed 
in infrastructure SIP submissions. The first two prongs, which are 
codified in section 110(a)(2)(D)(i)(I), are provisions that prohibit 
any source or other type of emissions activity in one state from 
contributing significantly to nonattainment of the NAAQS in another 
state (prong 1) and from interfering with maintenance of the NAAQS in 
another state (prong 2). The third and fourth prongs, which are 
codified in section 110(a)(2)(D)(i)(II), are provisions that prohibit 
emissions activity in one state from interfering with measures required 
to prevent significant deterioration of air quality in another state 
(prong 3) or from interfering with measures to protect visibility in 
another state (prong 4). Section 110(a)(2)(D)(ii) requires SIPs to 
include provisions ensuring compliance with sections 115 and 126 of the 
Act, relating to interstate and international pollution abatement.
    Through this action, EPA is proposing to conditionally approve the 
prong 4 portions of South Carolina's infrastructure SIP submissions for 
the 2008 8-hour Ozone, 2010 1-hour NO2, 2010 1-hour 
SO2, and 2012 annual PM2.5 NAAQS as discussed in 
section IV of this document.\1\ All other applicable infrastructure SIP 
requirements for these SIP submissions have been or will be addressed 
in separate rulemakings. A brief background regarding the NAAQS 
relevant to this proposal is provided below. For comprehensive 
information on these NAAQS, please refer to the Federal Register 
notices cited in the following subsections.
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    \1\ Under CAA section 110(k)(4), EPA may conditionally approve a 
SIP revision based on a commitment from a state to adopt specific 
enforceable measures by a date certain, but not later than one year 
from the date of approval. If the state fails to meet the commitment 
within one year of the final conditional approval, the conditional 
approval automatically becomes a disapproval on that date and EPA 
will issue a finding of disapproval.
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a. 2008 8-Hour Ozone NAAQS

    On March 12, 2008, EPA revised the 8-hour Ozone NAAQS to 0.075 
parts per million. See 73 FR 16436 (March 27, 2008). States were 
required to submit infrastructure SIP submissions for the 2008 8-hour 
Ozone NAAQS to EPA no later than March 12, 2011. South Carolina 
submitted its infrastructure SIP submission on July 17, 2012, for the 
2008 8-hour Ozone NAAQS.

b. 2010 1-Hour NO2 NAAQS

    On January 22, 2010, EPA established a new 1-hour primary NAAQS for 
NO2 at a level of 100 parts per billion, based on a 3-year 
average of the 98th percentile of the yearly distribution of 1-hour 
daily maximum concentrations. See 75 FR 6474 (February 9, 2010). States 
were required to submit infrastructure SIP submissions for the 2010 1-
hour NO2 NAAQS to EPA no later than January 22, 2013. South 
Carolina submitted its infrastructure SIP submission on April 30, 2014, 
for the 2010 1-hour NO2 NAAQS.

c. 2010 1-Hour SO2 NAAQS

    On June 2, 2010, EPA revised the primary SO2 NAAQS to an 
hourly standard of 75 parts per billion based on a 3-year average of 
the annual 99th percentile of 1-hour daily maximum concentrations. See 
75 FR 35520 (June 22, 2010). States were required to submit 
infrastructure SIP submissions for the 2010 1-hour SO2 NAAQS 
to EPA no later than June 2, 2013. South Carolina submitted its 
infrastructure SIP submission on May 8, 2014, for the 2010 1-hour 
SO2 NAAQS.

d. 2012 Annual PM2.5 NAAQS

    On December 14, 2012, EPA revised the primary annual 
PM2.5 NAAQS to 12 micrograms per cubic meter ([mu]g/m\3\). 
See 78 FR 3086 (January 15, 2013). States were required to submit 
infrastructure SIP submissions for the 2012 PM2.5 NAAQS to 
EPA no later than December 14, 2015. South Carolina submitted its 
infrastructure SIP submission on December 18, 2015, for the 2012 
PM2.5 NAAQS.

II. What is EPA's approach to the review of infrastructure SIP 
submissions?

    The requirement for states to make a SIP submission of this type 
arises out of section 110(a)(1). Pursuant to section 110(a)(1), states 
must make SIP submissions ``within 3 years (or such shorter period as 
the Administrator may prescribe) after the promulgation of a national 
primary ambient air quality standard (or any revision thereof),'' and 
these SIP submissions are to provide for the ``implementation, 
maintenance, and enforcement'' of such NAAQS. The statute directly 
imposes on states the duty to make these SIP submissions, and the 
requirement to make the submissions is not conditioned upon EPA's 
taking any action other than promulgating a new or revised NAAQS. 
Section 110(a)(2) includes a list of specific elements that ``each such 
plan'' submission must address.
    EPA has historically referred to these SIP submissions made for the 
purpose of satisfying the requirements of section 110(a)(1) and (2) as 
``infrastructure SIP'' submissions. Although the term ``infrastructure 
SIP'' does not appear in the CAA, EPA uses the term to distinguish this 
particular type of SIP submission from submissions that are intended to 
satisfy other SIP requirements under the CAA, such as ``nonattainment 
SIP'' or ``attainment plan SIP'' submissions to address the 
nonattainment planning requirements of part D of Title I of the CAA, 
``regional haze SIP'' submissions required by EPA rule to address the 
visibility protection requirements of section 169A of the CAA, and 
nonattainment new source review permit program submissions to address 
the permit requirements of CAA, Title I, part D.
    Section 110(a)(1) addresses the timing and general requirements for 
infrastructure SIP submissions and section 110(a)(2) provides more 
details concerning the required contents of these submissions. The list 
of required elements provided in section 110(a)(2) contains a wide 
variety of disparate provisions, some of which pertain to required 
legal authority, some of which pertain to required substantive program 
provisions, and some of which pertain to requirements for both 
authority and substantive program provisions.\2\ EPA therefore believes 
that while the timing requirement in section 110(a)(1) is unambiguous, 
some of the other statutory provisions are ambiguous. In particular, 
EPA believes that the list of required elements for infrastructure SIP 
submissions provided in section

[[Page 36844]]

110(a)(2) contains ambiguities concerning what is required for 
inclusion in an infrastructure SIP submission.
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    \2\ For example: Section 110(a)(2)(E)(i) provides that states 
must provide assurances that they have adequate legal authority 
under state and local law to carry out the SIP; Section 110(a)(2)(C) 
provides that states must have a SIP-approved program to address 
certain sources as required by part C of Title I of the CAA; and 
section 110(a)(2)(G) provides that states must have legal authority 
to address emergencies as well as contingency plans that are 
triggered in the event of such emergencies.
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    The following examples of ambiguities illustrate the need for EPA 
to interpret some section 110(a)(1) and section 110(a)(2) requirements 
with respect to infrastructure SIP submissions for a given new or 
revised NAAQS. One example of ambiguity is that section 110(a)(2) 
requires that ``each'' SIP submission must meet the list of 
requirements therein, while EPA has long noted that this literal 
reading of the statute is internally inconsistent and would create a 
conflict with the nonattainment provisions in part D of Title I of the 
CAA, which specifically address nonattainment SIP requirements.\3\ 
Section 110(a)(2)(I) pertains to nonattainment SIP requirements and 
part D addresses when attainment plan SIP submissions to address 
nonattainment area requirements are due. For example, section 172(b) 
requires EPA to establish a schedule for submission of such plans for 
certain pollutants when the Administrator promulgates the designation 
of an area as nonattainment, and section 107(d)(1)(B) allows up to two 
years or in some cases three years, for such designations to be 
promulgated.\4\ This ambiguity illustrates that rather than apply all 
the stated requirements of section 110(a)(2) in a strict literal sense, 
EPA must determine which provisions of section 110(a)(2) are applicable 
for a particular infrastructure SIP submission.
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    \3\ See, e.g., ``Rule To Reduce Interstate Transport of Fine 
Particulate Matter and Ozone (Clean Air Interstate Rule); Revisions 
to Acid Rain Program; Revisions to the NOX SIP Call; 
Final Rule,'' 70 FR 25162, at 25163-65 (May 12, 2005) (explaining 
relationship between timing requirement of section 110(a)(2)(D) 
versus section 110(a)(2)(I)).
    \4\ EPA notes that this ambiguity within section 110(a)(2) is 
heightened by the fact that various subparts of part D set specific 
dates for submission of certain types of SIP submissions in 
designated nonattainment areas for various pollutants. Note, e.g., 
that section 182(a)(1) provides specific dates for submission of 
emissions inventories for the ozone NAAQS. Some of these specific 
dates are necessarily later than three years after promulgation of 
the new or revised NAAQS.
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    Another example of ambiguity within section 110(a)(1) and (2) with 
respect to infrastructure SIPs pertains to whether states must meet all 
of the infrastructure SIP requirements in a single SIP submission, and 
whether EPA must act upon such SIP submission in a single action. 
Although section 110(a)(1) directs states to submit ``a plan'' to meet 
these requirements, EPA interprets the CAA to allow states to make 
multiple SIP submissions separately addressing infrastructure SIP 
elements for the same NAAQS. If states elect to make such multiple SIP 
submissions to meet the infrastructure SIP requirements, EPA can elect 
to act on such submissions either individually or in a larger combined 
action.\5\ Similarly, EPA interprets the CAA to allow it to take action 
on the individual parts of one larger, comprehensive infrastructure SIP 
submission for a given NAAQS without concurrent action on the entire 
submission. For example, EPA has sometimes elected to act at different 
times on various elements and sub-elements of the same infrastructure 
SIP submission.\6\
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    \5\ See, e.g., ``Approval and Promulgation of Implementation 
Plans; New Mexico; Revisions to the New Source Review (NSR) State 
Implementation Plan (SIP); Prevention of Significant Deterioration 
(PSD) and Nonattainment New Source Review (NNSR) Permitting,'' 78 FR 
4339 (January 22, 2013) (EPA's final action approving the structural 
PSD elements of the New Mexico SIP submitted by the State separately 
to meet the requirements of EPA's 2008 PM2.5 NSR rule), 
and ``Approval and Promulgation of Air Quality Implementation Plans; 
New Mexico; Infrastructure and Interstate Transport Requirements for 
the 2006 PM2.5 NAAQS,'' 78 FR 4337 (January 22, 2013) 
(EPA's final action on the infrastructure SIP for the 2006 
PM2.5 NAAQS).
    \6\ On December 14, 2007, the State of Tennessee, through the 
Tennessee Department of Environment and Conservation, made a SIP 
revision to EPA demonstrating that the State meets the requirements 
of sections 110(a)(1) and (2). EPA proposed action for 
infrastructure SIP elements (C) and (J) on January 23, 2012 (77 FR 
3213) and took final action on March 14, 2012 (77 FR 14976). On 
April 16, 2012 (77 FR 22533) and July 23, 2012 (77 FR 42997), EPA 
took separate proposed and final actions on all other section 
110(a)(2) infrastructure SIP elements of Tennessee's December 14, 
2007 submittal.
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    Ambiguities within section 110(a)(1) and (2) may also arise with 
respect to infrastructure SIP submission requirements for different 
NAAQS. Thus, EPA notes that not every element of section 110(a)(2) 
would be relevant, or as relevant, or relevant in the same way, for 
each new or revised NAAQS. The states' attendant infrastructure SIP 
submissions for each NAAQS therefore could be different. For example, 
the monitoring requirements that a state might need to meet in its 
infrastructure SIP submission for purposes of section 110(a)(2)(B) 
could be very different for different pollutants, because the content 
and scope of a state's infrastructure SIP submission to meet this 
element might be very different for an entirely new NAAQS than for a 
minor revision to an existing NAAQS.\7\
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    \7\ For example, implementation of the 1997 PM2.5 
NAAQS required the deployment of a system of new monitors to measure 
ambient levels of that new indicator species for the new NAAQS.
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    EPA notes that interpretation of section 110(a)(2) is also 
necessary when EPA reviews other types of SIP submissions required 
under the CAA. Therefore, as with infrastructure SIP submissions, EPA 
also has to identify and interpret the relevant elements of section 
110(a)(2) that logically apply to these other types of SIP submissions. 
For example, section 172(c)(7) requires attainment plan SIP submissions 
required by part D to meet the ``applicable requirements'' of section 
110(a)(2); thus, attainment plan SIP submissions must meet the 
requirements of section 110(a)(2)(A) regarding enforceable emission 
limits and control measures and section 110(a)(2)(E)(i) regarding air 
agency resources and authority. By contrast, it is clear that 
attainment plan SIP submissions required by part D would not need to 
meet the portion of section 110(a)(2)(C) that pertains to the PSD 
program required in part C of Title I of the CAA, because PSD does not 
apply to a pollutant for which an area is designated nonattainment and 
thus subject to part D planning requirements. As this example 
illustrates, each type of SIP submission may implicate some elements of 
section 110(a)(2) but not others.
    Given the potential for ambiguity in some of the statutory language 
of section 110(a)(1) and section 110(a)(2), EPA believes that it is 
appropriate to interpret the ambiguous portions of section 110(a)(1) 
and section 110(a)(2) in the context of acting on a particular SIP 
submission. In other words, EPA assumes that Congress could not have 
intended that each and every SIP submission, regardless of the NAAQS in 
question or the history of SIP development for the relevant pollutant, 
would meet each of the requirements, or meet each of them in the same 
way. Therefore, EPA has adopted an approach under which it reviews 
infrastructure SIP submissions against the list of elements in section 
110(a)(2), but only to the extent each element applies for that 
particular NAAQS.
    Historically, EPA has elected to use guidance documents to make 
recommendations to states for infrastructure SIPs, in some cases 
conveying needed interpretations on newly arising issues and in some 
cases conveying interpretations that have already been developed and 
applied to individual SIP submissions for particular elements.\8\ EPA 
most recently

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issued guidance for infrastructure SIPs on September 13, 2013 (2013 
Guidance).\9\ EPA developed this document to provide states with up-to-
date guidance for infrastructure SIPs for any new or revised NAAQS. 
Within this guidance, EPA describes the duty of states to make 
infrastructure SIP submissions to meet basic structural SIP 
requirements within three years of promulgation of a new or revised 
NAAQS. EPA also made recommendations about many specific subsections of 
section 110(a)(2) that are relevant in the context of infrastructure 
SIP submissions.\10\ The guidance also discusses the substantively 
important issues that are germane to certain subsections of section 
110(a)(2). EPA interprets section 110(a)(1) and (2) such that 
infrastructure SIP submissions need to address certain issues and need 
not address others. Accordingly, EPA reviews each infrastructure SIP 
submission for compliance with the applicable statutory provisions of 
section 110(a)(2), as appropriate.
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    \8\ EPA notes, however, that nothing in the CAA requires EPA to 
provide guidance or to promulgate regulations for infrastructure SIP 
submissions. The CAA directly applies to states and requires the 
submission of infrastructure SIP submissions, regardless of whether 
or not EPA provides guidance or regulations pertaining to such 
submissions. EPA elects to issue such guidance in order to assist 
states, as appropriate.
    \9\ ``Guidance on Infrastructure State Implementation Plan (SIP) 
Elements under Clean Air Act Sections 110(a)(1) and 110(a)(2),'' 
Memorandum from Stephen D. Page, September 13, 2013.
    \10\ EPA's September 13, 2013, guidance did not make 
recommendations with respect to infrastructure SIP submissions to 
address section 110(a)(2)(D)(i)(I). EPA issued the guidance shortly 
after the U.S. Supreme Court agreed to review the D.C. Circuit 
decision in EME Homer City, 696 F.3d 7 (D.C. Cir. 2012) which had 
interpreted the requirements of section 110(a)(2)(D)(i)(I). In light 
of the uncertainty created by ongoing litigation, EPA elected not to 
provide additional guidance on the requirements of section 
110(a)(2)(D)(i)(I) at that time. As the guidance is neither binding 
nor required by statute, whether EPA elects to provide guidance on a 
particular section has no impact on a state's CAA obligations.
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    As an example, section 110(a)(2)(E)(ii) is a required element of 
section 110(a)(2) for infrastructure SIP submissions. Under this 
element, a state must meet the substantive requirements of section 128, 
which pertain to state boards that approve permits or enforcement 
orders and heads of executive agencies with similar powers. Thus, EPA 
reviews infrastructure SIP submissions to ensure that the state's 
implementation plan appropriately addresses the requirements of section 
110(a)(2)(E)(ii) and section 128. The 2013 Guidance explains EPA's 
interpretation that there may be a variety of ways by which states can 
appropriately address these substantive statutory requirements, 
depending on the structure of an individual state's permitting or 
enforcement program (e.g., whether permits and enforcement orders are 
approved by a multi-member board or by a head of an executive agency). 
However they are addressed by the state, the substantive requirements 
of Section 128 are necessarily included in EPA's evaluation of 
infrastructure SIP submissions because section 110(a)(2)(E)(ii) 
explicitly requires that the state satisfy the provisions of section 
128.
    As another example, EPA's review of infrastructure SIP submissions 
with respect to the PSD program requirements in section 110(a)(2)(C), 
(D)(i)(II), and (J) focuses upon the structural PSD program 
requirements contained in part C and EPA's PSD regulations. Structural 
PSD program requirements include provisions necessary for the PSD 
program to address all regulated sources and NSR pollutants, including 
Greenhouse Gases. By contrast, structural PSD program requirements do 
not include provisions that are not required under EPA's regulations at 
40 CFR 51.166 but are merely available as an option for the state, such 
as the option to provide grandfathering of complete permit applications 
with respect to the PM2.5 NAAQS. Accordingly, the latter 
optional provisions are types of provisions EPA considers irrelevant in 
the context of an infrastructure SIP action.
    For other section 110(a)(2) elements, however, EPA's review of a 
state's infrastructure SIP submission focuses on assuring that the 
state's implementation plan meets basic structural requirements. For 
example, section 110(a)(2)(C) includes, inter alia, the requirement 
that states have a program to regulate minor new sources. Thus, EPA 
evaluates whether the state has an EPA-approved minor new source review 
program and whether the program addresses the pollutants relevant to 
that NAAQS. In the context of acting on an infrastructure SIP 
submission, however, EPA does not think it is necessary to conduct a 
review of each and every provision of a state's existing minor source 
program (i.e., already in the existing SIP) for compliance with the 
requirements of the CAA and EPA's regulations that pertain to such 
programs.
    With respect to certain other issues, EPA does not believe that an 
action on a state's infrastructure SIP submission is necessarily the 
appropriate type of action in which to address possible deficiencies in 
a state's existing SIP. These issues include: (i) Existing provisions 
related to excess emissions from sources during periods of startup, 
shutdown, or malfunction (SSM) that may be contrary to the CAA and 
EPA's policies addressing such excess emissions; \11\ (ii) existing 
provisions related to ``director's variance'' or ``director's 
discretion'' that may be contrary to the CAA because they purport to 
allow revisions to SIP-approved emissions limits while limiting public 
process or not requiring further approval by EPA; and (iii) existing 
provisions for PSD programs that may be inconsistent with current 
requirements of EPA's ``Final NSR Improvement Rule,'' 67 FR 80186 
(December 31, 2002), as amended by 72 FR 32526 (June 13, 2007) (NSR 
Reform). Thus, EPA believes that it may approve an infrastructure SIP 
submission without scrutinizing the totality of the existing SIP for 
such potentially deficient provisions and may approve the submission 
even if it is aware of such existing provisions.\12\ It is important to 
note that EPA's approval of a state's infrastructure SIP submission 
should not be construed as explicit or implicit re-approval of any 
existing potentially deficient provisions that relate to the three 
specific issues just described.
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    \11\ Subsequent to issuing the 2013 Guidance, EPA's 
interpretation of the CAA with respect to the approvability of 
affirmative defense provisions in SIPs has changed. 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,'' 80 FR 33839 (June 12, 2015). As a 
result, EPA's 2013 Guidance (p. 21 & n.30) no longer represents the 
EPA's view concerning the validity of affirmative defense 
provisions, in light of the requirements of section 113 and section 
304.
    \12\ By contrast, EPA notes that if a state were to include a 
new provision in an infrastructure SIP submission that contained a 
legal deficiency, such as a new exemption or affirmative defense for 
excess emissions during SSM events, then EPA would need to evaluate 
that provision for compliance against the rubric of applicable CAA 
requirements in the context of the action on the infrastructure SIP.
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    EPA's approach to review of infrastructure SIP submissions is to 
identify the CAA requirements that are logically applicable to that 
submission. EPA believes that this approach to the review of a 
particular infrastructure SIP submission is appropriate, because it 
would not be reasonable to read the general requirements of section 
110(a)(1) and the list of elements in section 110(a)(2) as requiring 
review of each and every provision of a state's existing SIP against 
all requirements in the CAA and EPA regulations merely for purposes of 
assuring that the state in question has the basic structural elements 
for a functioning SIP for a new or revised NAAQS. Because SIPs have 
grown by accretion over the decades as statutory and regulatory 
requirements under the CAA have evolved, they may

[[Page 36846]]

include some outmoded provisions and historical artifacts. These 
provisions, while not fully up to date, nevertheless may not pose a 
significant problem for the purposes of ``implementation, maintenance, 
and enforcement'' of a new or revised NAAQS when EPA evaluates adequacy 
of the infrastructure SIP submission. EPA believes that a better 
approach is for states and EPA to focus attention on those elements of 
section 110(a)(2) of the CAA most likely to warrant a specific SIP 
revision due to the promulgation of a new or revised NAAQS or other 
factors.
    For example, EPA's 2013 Guidance gives simpler recommendations with 
respect to carbon monoxide than other NAAQS pollutants to meet the 
visibility requirements of section 110(a)(2)(D)(i)(II), because carbon 
monoxide does not affect visibility. As a result, an infrastructure SIP 
submission for any future new or revised NAAQS for carbon monoxide need 
only state this fact in order to address the visibility prong of 
section 110(a)(2)(D)(i)(II).
    Finally, EPA believes that its approach with respect to 
infrastructure SIP requirements is based on a reasonable reading of 
section 110(a)(1) and (2) because the CAA provides other avenues and 
mechanisms to address specific substantive deficiencies in existing 
SIPs. These other statutory tools allow EPA to take appropriately 
tailored action, depending upon the nature and severity of the alleged 
SIP deficiency. Section 110(k)(5) authorizes EPA to issue a ``SIP 
call'' whenever the Agency determines that a state's SIP is 
substantially inadequate to attain or maintain the NAAQS, to mitigate 
interstate transport, or to otherwise comply with the CAA.\13\ Section 
110(k)(6) authorizes EPA to correct errors in past actions, such as 
past approvals of SIP submissions.\14\ Significantly, EPA's 
determination that an action on a state's infrastructure SIP submission 
is not the appropriate time and place to address all potential existing 
SIP deficiencies does not preclude EPA's subsequent reliance on 
provisions in section 110(a)(2) as part of the basis for action to 
correct those deficiencies at a later time. For example, although it 
may not be appropriate to require a state to eliminate all existing 
inappropriate director's discretion provisions in the course of acting 
on an infrastructure SIP submission, EPA believes that section 
110(a)(2)(A) may be among the statutory bases that EPA relies upon in 
the course of addressing such deficiency in a subsequent action.\15\
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    \13\ For example, EPA issued a SIP call to Utah to address 
specific existing SIP deficiencies related to the treatment of 
excess emissions during SSM events. See ``Finding of Substantial 
Inadequacy of Implementation Plan; Call for Utah State 
Implementation Plan Revisions,'' 74 FR 21639 (April 18, 2011).
    \14\ EPA has used this authority to correct errors in past 
actions on SIP submissions related to PSD programs. See ``Limitation 
of Approval of Prevention of Significant Deterioration Provisions 
Concerning Greenhouse Gas Emitting-Sources in State Implementation 
Plans; Final Rule,'' 75 FR 82536 (December 30, 2010). EPA has 
previously used its authority under section 110(k)(6) of the CAA to 
remove numerous other SIP provisions that the Agency determined it 
had approved in error. See, e.g., 61 FR 38664 (July 25, 1996) and 62 
FR 34641 (June 27, 1997) (corrections to American Samoa, Arizona, 
California, Hawaii, and Nevada SIPs); 69 FR 67062, November 16, 2004 
(corrections to California SIP); and 74 FR 57051 (November 3, 2009) 
(corrections to Arizona and Nevada SIPs).
    \15\ See, e.g., EPA's disapproval of a SIP submission from 
Colorado on the grounds that it would have included a director's 
discretion provision inconsistent with CAA requirements, including 
section 110(a)(2)(A). See, e.g., 75 FR 42342 at 42344 (July 21, 
2010) (proposed disapproval of director's discretion provisions); 76 
FR 4540 (January 26, 2011) (final disapproval of such provisions).
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III. What are the Prong 4 requirements?

    Section 110(a)(2)(D)(i)(II) includes a requirement that a state's 
implementation plan contain provisions prohibiting sources in that 
state from emitting pollutants in amounts that interfere with any other 
state's efforts to protect visibility under part C of Title I of the 
CAA (which includes sections 169A and 169B). The 2013 Guidance states 
that these prong 4 requirements can be satisfied by approved SIP 
provisions that EPA has found to adequately address any contribution of 
that state's sources to impacts on visibility program requirements in 
other states. The 2013 Guidance also states that EPA interprets this 
prong to be pollutant-specific, such that the infrastructure SIP 
submission need only address the potential for interference with 
protection of visibility caused by the pollutant (including precursors) 
to which the new or revised NAAQS applies.
    The 2013 Guidance delineates two ways in which a state's 
infrastructure SIP may satisfy prong 4. The first way is through an air 
agency's confirmation in its infrastructure SIP submission that it has 
an EPA-approved regional haze SIP that fully meets the requirements of 
40 CFR 51.308 or 51.309. 40 CFR 51.308 and 51.309 specifically require 
that a state participating in a regional planning process include all 
measures needed to achieve its apportionment of emission reduction 
obligations agreed upon through that process. A fully approved regional 
haze SIP will ensure that emissions from sources under an air agency's 
jurisdiction are not interfering with measures required to be included 
in other air agencies' plans to protect visibility.
    Alternatively, in the absence of a fully approved regional haze 
SIP, a state may meet the requirements of prong 4 through a 
demonstration in its infrastructure SIP submission that emissions 
within its jurisdiction do not interfere with other air agencies' plans 
to protect visibility. Such an infrastructure SIP submission would need 
to include measures to limit visibility-impairing pollutants and ensure 
that the reductions conform with any mutually agreed regional haze 
reasonable progress goals for mandatory Class I areas in other states.

IV. What is EPA's analysis of how South Carolina addressed Prong 4?

    South Carolina's July 17, 2012, 2008 8-hour Ozone submission; April 
30, 2014, 2010 1-hour NO2 submission; May 8, 2014, 2010 1-
hour SO2 submission; and December 18, 2015, 2012 annual 
PM2.5 submission cite to the State's regional haze SIP as 
satisfying prong 4 requirements.\16\ However, as explained below, EPA 
has not yet fully approved South Carolina's regional haze SIP because 
the SIP relies on the Clean Air Interstate Rule (CAIR) to satisfy the 
nitrogen oxides (NOX) and SO2 Best Available 
Retrofit Technology (BART) requirements for the CAIR-subject electric 
generating units (EGUs) in the State and the requirement for a long-
term strategy sufficient to achieve the state-adopted reasonable 
progress goals.\17\
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    \16\ The April 30, 2014, 2010 1-hour NO2 submission; 
May 8, 2014, 2010 1-hour SO2 submission; and December 18, 
2015 also cite to the State's December 2012 regional haze progress 
report.
    \17\ CAIR, promulgated in 2005, required 27 states and the 
District of Columbia to reduce emissions of NOX and 
SO2 that significantly contribute to, or interfere with 
maintenance of, the 1997 NAAQS for fine particulates and/or ozone in 
any downwind state. CAIR imposed specified emissions reduction 
requirements on each affected State, and established several EPA-
administered cap and trade programs for EGUs that States could join 
as a means to meet these requirements.
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    EPA demonstrated that CAIR achieved greater reasonable progress 
toward the national visibility goal than BART for NOX and 
SO2 at BART-eligible EGUs in CAIR affected states, and 
revised the regional haze rule to provide that states participating in 
CAIR's cap-and-trade programs need not require affected BART-eligible 
EGUs to install, operate, and maintain BART for emissions of 
SO2 and NOX. See 70 FR 39104 (July 6, 2005). As a 
result, a number of states in the CAIR region designed their regional 
haze SIPs to rely

[[Page 36847]]

on CAIR as an alternative to NOX and SO2 BART for 
CAIR-subject EGUs. These states also relied on CAIR as an element of a 
long-term strategy for achieving their reasonable progress goals.
    The United States Court of Appeals for the District of Columbia 
Circuit (D.C. Circuit) initially vacated CAIR in 2008,\18\ but 
ultimately remanded the rule to EPA without vacatur to preserve the 
environmental benefits provided by CAIR.\19\ On August 8, 2011 (76 FR 
48208), acting on the D.C. Circuit's remand, EPA promulgated the Cross-
State Air Pollution Rule (CSAPR) to replace CAIR and thus to address 
the interstate transport of emissions contributing to nonattainment and 
interfering with maintenance of the two air quality standards covered 
by CAIR as well as the 2006 PM2.5 NAAQS.
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    \18\ North Carolina v. EPA, 531 F.3d 896 (D.C. Cir. 2008).
    \19\ North Carolina v. EPA, 550 F.3d 1176 (D.C. Cir. 2008).
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    Due to CAIR's status as a temporary measure following the D.C. 
Circuit's 2008 ruling, EPA could not fully approve regional haze SIP 
revisions to the extent that they relied on CAIR to satisfy the BART 
requirement and the requirement for a long-term strategy sufficient to 
achieve the state-adopted reasonable progress goals. On these grounds, 
EPA finalized a limited disapproval of South Carolina's regional haze 
SIP on June 7, 2012 (77 FR 33642), triggering the requirement for EPA 
to promulgate a Federal Implementation Plan (FIP) unless South Carolina 
submitted and EPA approved a SIP revision that corrected the 
deficiencies. EPA finalized a limited approval of South Carolina's 
regional haze SIP on June 28, 2012 (77 FR 38509), as meeting the 
remaining applicable regional haze requirements set forth in the CAA 
and the regional haze rule.
    Numerous parties filed petitions for review of CSAPR in the D.C. 
Circuit, and on August 21, 2012, the court issued its ruling, vacating 
and remanding CSAPR to EPA and ordering continued implementation of 
CAIR. EME Homer City Generation, L.P. v. EPA, 696 F.3d 7, 38 (D.C. Cir. 
2012). The D.C. Circuit's vacatur of CSAPR was reversed by the United 
States Supreme Court on April 29, 2014, and the case was remanded to 
the D.C. Circuit to resolve remaining issues in accordance with the 
high court's ruling. EPA v. EME Homer City Generation, L.P., 134 S. Ct. 
1584 (2014). On remand, the D.C. Circuit affirmed CSAPR in most 
respects, but invalidated without vacating some of the CSAPR budgets as 
to a number of states. EME Homer City Generation, L.P. v. EPA, 795 F.3d 
118 (D.C. Cir. 2015). The remanded budgets include the Phase 2 
SO2 emissions budget for South Carolina.\20\
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    \20\ The D.C. Circuit also invalidated the Phase 2 ozone season 
NOX budget for South Carolina. EPA has proposed to 
address the court's remand of the Phase 2 ozone season 
NOX budgets in a notice of proposed rulemaking published 
on December 3, 2015 (80 FR 75706).
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    Although South Carolina's infrastructure SIP revisions cite to the 
regional haze program as satisfying the requirements of Prong 4, the 
State may not currently rely on its regional haze SIP to satisfy these 
requirements because the regional haze SIP is not fully approved. In 
addition, these revisions do not otherwise demonstrate that emissions 
within the State's jurisdiction do not interfere with other states' 
plans to protect visibility. Therefore, on April 19, 2016, South 
Carolina submitted a commitment letter to EPA requesting conditional 
approval of the prong 4 portions of the aforementioned infrastructure 
SIP revisions.\21\ In this letter, South Carolina commits to satisfy 
the prong 4 requirements for the 2008 8-hour ozone NAAQS, 2010 1-hour 
NO2 NAAQS, 2010 1-hour SO2 NAAQS, and 2012 
PM2.5 NAAQS by providing a SIP revision that adopts 
provisions for participation in the CSAPR annual NOX and 
annual SO2 trading programs, including annual NOX 
and annual SO2 budgets that are at least as stringent as the 
budgets codified for South Carolina at 40 CFR 97.710(a) (SO2 
Group 2 trading budgets) and 40 CFR 97.410(a) (NOX Annual 
trading budgets). South Carolina will rely on this SIP revision 
adopting such budgets to submit a concurrent SIP revision specifically 
addressing the visibility requirements of prong 4. In its commitment 
letter, South Carolina commits to providing these two concurrent SIP 
revisions within one year of EPA's final conditional approval of the 
prong 4 portions of the infrastructure SIP revisions and provides an 
anticipated schedule for these revisions. If the revised infrastructure 
SIP revision relies on a fully approvable regional haze SIP, South 
Carolina also commits to providing the necessary regional haze SIP 
revision to EPA within one year of EPA's final conditional approval.
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    \21\ South Carolina's April 19, 2016, commitment letter is 
available in the docket for today's proposed action.
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    If South Carolina meets its commitment within one year of final 
conditional approval, the prong 4 portions of the conditionally 
approved infrastructure SIP submissions will remain a part of the SIP 
until EPA takes final action approving or disapproving the new SIP 
revision(s). However, if the State fails to submit these revisions 
within the one-year timeframe, the conditional approval will 
automatically become a disapproval one year from EPA's final 
conditional approval and EPA will issue a finding of disapproval. EPA 
is not required to propose the finding of disapproval. If the 
conditional approval is converted to a disapproval, the final 
disapproval triggers the FIP requirement under CAA section 110(c).

V. Proposed Action

    As described above, EPA is proposing to conditionally approve the 
prong 4 portions of South Carolina's July 17, 2008 8-hour Ozone 
infrastructure SIP submission; April 30, 2014, 2010 1-hour 
NO2 infrastructure SIP submission; May 8, 2014, 2010 1-hour 
SO2 infrastructure SIP submission; and December 18, 2015, 
2012 annual PM2.5 infrastructure SIP submission. All other 
applicable infrastructure requirements for these SIP submissions have 
been or will be addressed in separate rulemakings.

VI. 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 that they meet the criteria of the CAA. Accordingly, this 
proposed action merely approves state law as meeting federal 
requirements and does not impose additional requirements beyond those 
imposed by state law. For that reason, this proposed 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);
     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

[[Page 36848]]

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
     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).
    In addition, this proposed action for the state of South Carolina 
does not have Tribal implications as specified by Executive Order 13175 
(65 FR 67249, November 9, 2000). The Catawba Indian Nation Reservation 
is located within the State of South Carolina. Pursuant to the Catawba 
Indian Claims Settlement Act, South Carolina statute 27-16-120, ``all 
state and local environmental laws and regulations apply to the 
[Catawba Indian Nation] and Reservation and are fully enforceable by 
all relevant state and local agencies and authorities.'' However, EPA 
has determined that because this proposed rule does not have 
substantial direct effects on an Indian Tribe because, as noted above, 
this action is not approving any specific rule, but rather proposing 
that South Carolina's already approved SIP meets certain CAA 
requirements. EPA notes this action will not impose substantial direct 
costs on Tribal governments or preempt Tribal law.

List of Subjects in 40 CFR Part 52

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

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

    Dated: May 26, 2016.
Heather McTeer Toney,
Regional Administrator, Region 4.
[FR Doc. 2016-13606 Filed 6-7-16; 8:45 am]
 BILLING CODE 6560-50-P