[Federal Register: January 11, 2010 (Volume 75, Number 6)]
[Notices]
[Page 1396-1397]
[DOCID:fr11ja10-57]

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DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

[Docket No. FDA-2009-N-0664]

The General Hospital and Personal Use Devices Panel of the
Medical Devices Advisory Committee; Notice of Meeting

AGENCY:  Food and Drug Administration, HHS.

ACTION:  Notice.

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    This notice announces a forthcoming meeting of a public advisory
committee of the Food and Drug Administration (FDA). The meeting will
be open to the public.
    Name of Committee: General Hospital and Personal Use Devices Panel
of the Medical Devices Advisory Committee.
    General Function of the Committee: To provide advice and
recommendations to the agency on FDA's regulatory issues.
    Date and Time: The meeting will be held on March 5, 2010, from 8
a.m. to 5 p.m.
    Location: Hilton Washington DC North/Gaithersburg, Salons C, D and
E, 620 Perry Pkwy., Gaithersburg, MD.
    Contact Person: Tracy Phillips, Center for Devices and Radiological
Health, Food and Drug Administration, 10903 New Hampshire Ave., Silver
Spring, MD 20993, or FDA Advisory Committee Information Line, 1-800-
741-8138<PHONE_NUMBER> in the Washington, DC area), code<PHONE_NUMBER>.
Please call the Information Line for up-to-date information on this
meeting. A notice in the Federal Register about last minute
modifications that impact a previously announced advisory committee
meeting cannot always be published quickly enough to provide timely
notice. Therefore, you should always check the agency's Web site and
call the appropriate advisory committee hot line/phone line to learn
about possible modifications before coming to the meeting.
    Agenda: On March 5, 2010, the committee will discuss and make
recommendations regarding clinical risks and benefits of post-market
actions in response to insulin pump failures. Insulin pumps are
intended for continuous delivery of insulin at set and variable rates
and as an aid in the management of diabetes mellitus in persons
requiring insulin.
    FDA intends to make background material available to the public no
later than 2 business days before the meeting. If FDA is unable to post
the background material on its Web site prior to the meeting, the
background material will be made publicly available at the location of
the advisory committee meeting, and the background material will be
posted on FDA's Web site after the meeting. Background material is
available at http://www.fda.gov/AdvisoryCommittees/Calendar/
default.htm. Scroll down to the appropriate advisory committee link.
    Procedure: Interested persons may present data, information, or
views, orally or in writing, on issues pending before the committee.
Written submissions may be made to the contact person on or before
February 22, 2010. Oral presentations from the public will be scheduled
immediately following

lunch. Those desiring to make formal oral presentations should notify
the contact person and submit a brief statement of the general nature
of the evidence or arguments they wish to present, the names and
addresses of proposed participants, and an indication of the
approximate time requested to make their presentation on or before
February 11, 2010. Time allotted for each presentation may be limited.
If the number of registrants requesting to speak is greater than can be
reasonably accommodated during the scheduled open public hearing
session, FDA may conduct a lottery to determine the speakers for the
scheduled open public hearing session. The contact person will notify
interested persons regarding their request to speak by February 12,
2010.
    Persons attending FDA's advisory committee meetings are advised
that the agency is not responsible for providing access to electrical
outlets.
    FDA welcomes the attendance of the public at its advisory committee
meetings and will make every effort to accommodate persons with
physical disabilities or special needs. If you require special
accommodations due to a disability, please contact AnnMarie Williams at
301-796-5966 at least 7 days in advance of the meeting.
    FDA is committed to the orderly conduct of its advisory committee
meetings. Please visit our Web site at http://www.fda.gov/
AdvisoryCommittees/AboutAdvisoryCommittees/ucm111462.htm for procedures
on public conduct during advisory committee meetings.
    Notice of this meeting is given under the Federal Advisory
Committee Act (5 U.S.C. app. 2).

    Dated: January 5, 2010.
David Dorsey,
Acting Deputy Commissioner for Policy, Planning and Budget.
[FR Doc. 2010-174 Filed 1-8-10; 8:45 am]
BILLING CODE 4160-01-S


[Federal Register Volume 84, Number 78 (Tuesday, April 23, 2019)]
[Proposed Rules]
[Pages 16799-16809]
[FR Doc No: 2019-07921]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2018-0665; FRL-9992-52-Region 4]

Air Plan Approval; SC; 2010 1-Hour SO2 NAAQS Transport
Infrastructure

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
approve South Carolina's June 25, 2018, State Implementation Plan (SIP)
submission pertaining to the ``good neighbor'' provision of the Clean
Air Act (CAA or Act) for the 2010 1-hour sulfur dioxide
(SO2) National Ambient Air Quality Standard (NAAQS). The
good neighbor provision requires each state's implementation plan to
address the interstate transport of air pollution in amounts that
contribute significantly to nonattainment, or interfere with
maintenance, of a NAAQS in any other state. In this action, EPA is
proposing to determine that South Carolina's SIP contains adequate
provisions to prohibit emissions within the State from contributing
significantly to nonattainment or interfering with maintenance of the
2010 1-hour SO2 NAAQS in any other state.

DATES: Written comments must be received on or before May 23, 2019.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2018-0665 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: Michele Notarianni, 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. Ms. Notarianni can be reached via phone number (404) 562-
9031 or via electronic mail at [email protected].

SUPPLEMENTARY INFORMATION:

I. Background

A. Infrastructure SIPs

    On June 2, 2010, EPA promulgated a revised primary SO2
NAAQS with a level of 75 parts per billion (ppb), based on a 3-year
average of the annual 99th percentile of 1-hour daily maximum
concentrations. See 75 FR 35520 (June 22, 2010). Pursuant to section
110(a)(1) of the CAA, states are required to submit SIPs meeting the
applicable requirements of section 110(a)(2) within three years after
promulgation of a new or revised NAAQS or within such shorter period as
EPA may prescribe. These SIPs, which EPA has historically referred to
as ``infrastructure SIPs,'' are to provide for the ``implementation,
maintenance, and enforcement'' of such NAAQS, and the requirements are
designed to ensure that the structural components of each state's air
quality management program are adequate to meet the state's
responsibility under the CAA. Section 110(a) of the CAA requires states
to make a SIP submission to EPA for a new or revised NAAQS, but the
contents of individual state submissions may vary depending upon the
facts and circumstances. The content of the changes proposed in such
SIP submissions may also vary depending upon what provisions the
state's approved SIP already contains. Section 110(a)(2) requires
states to address basic SIP elements such as requirements for
monitoring, basic program requirements, and legal authority that are
designed to assure attainment and maintenance of the NAAQS. A detailed
history, interpretation, and rationale of these SIPs and their
requirements can be found in, among other documents, EPA's March 7,
2016 (81 FR 11718), notice of proposed rulemaking related to
infrastructure SIP requirements for the 2010 1-hour SO2
NAAQS for South Carolina in the section titled, What is EPA's approach
to the review of infrastructure SIP submissions?
    Section 110(a)(2)(D)(i)(I) of the CAA requires SIPs to include
provisions prohibiting any source or other type of emissions activity
in one state from emitting any air pollutant in amounts that will
contribute significantly to nonattainment, or interfere with
maintenance, of the NAAQS in another state. The two clauses of this
section are referred to as prong 1 (significant contribution to
nonattainment) and prong 2 (interference with maintenance of the
NAAQS).
    On June 25, 2018, the South Carolina Department of Health and
Environmental Control (SC DHEC) submitted a revision to the South
Carolina SIP addressing only prongs 1 and 2 of CAA section
110(a)(2)(D)(i)(I) for the 2010 1-hour SO2 NAAQS.\1\ EPA is
proposing to approve SC DHEC's June 25, 2018, SIP submission which
certifies that existing SIP provisions satisfy the State's obligation
for prongs 1 and 2 for the 2010 1-hour SO2 NAAQS. All other
elements related to the infrastructure requirements of section
110(a)(2) for the 2010 1-hour SO2 NAAQS for South Carolina
are addressed in separate rulemakings.\2\
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    \1\ On May 8, 2014, SC DHEC submitted a SIP revision addressing
all infrastructure elements with respect to the 2010 1-hour
SO2 NAAQS with the exception of prongs 1 and 2 of CAA
110(a)(2)(D)(i)(I).
    \2\ EPA acted on the other elements of South Carolina's May 8,
2014, infrastructure SIP submission for the 2010 1-hour
SO2 NAAQS on May 24, 2016 (81 FR 32651) and September 24,
2018 (83 FR 48237).
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B. EPA's Designations for the 2010 1-Hour SO2 NAAQS

    In this action, EPA has considered information from the 2010 1-hour
SO2 NAAQS designations process, as discussed in more detail
in section III.C of this document. For this reason, a brief summary of
EPA's designations process for the 2010 1-hour SO2 NAAQS is
included here.\3\
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    \3\ While designations may provide useful information for
purposes of analyzing transport, particularly for a more source-
specific pollutant such as SO2, EPA notes that
designations themselves are not dispositive of whether or not upwind
emissions are impacting areas in downwind states. EPA has
consistently taken the position that as to impacts, CAA section
110(a)(2)(D) refers only to prevention of `nonattainment' in other
states, not to prevention of nonattainment in designated
nonattainment areas or any similar formulation requiring that
designations for downwind nonattainment areas must first have
occurred. See e.g., Clean Air Interstate Rule, 70 FR 25162, 25265
(May 12, 2005); Cross-State Air Pollution Rule, 76 FR 48208, 48211
(Aug. 8, 2011); Final Response to Petition from New Jersey Regarding
SO2 Emissions From the Portland Generating Station, 76 FR
69052 (Nov. 7, 2011) (finding facility in violation of the
prohibitions of CAA section 110(a)(2)(D)(i)(I) with respect to the
2010 1-hour SO2 NAAQS prior to issuance of designations
for that standard).
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    After the promulgation of a new or revised NAAQS, EPA is required
to designate areas as ``nonattainment,'' ``attainment,'' or
``unclassifiable,'' pursuant to section 107(d)(1) of the CAA. The
process for designating areas following promulgation of a new or
revised NAAQS is contained in section 107(d) of the CAA. The CAA
requires EPA to complete the initial designations process within two
years of promulgating a new or revised standard. If the Administrator
has insufficient information to make these designations by that
deadline, EPA has the authority to extend the deadline for completing
designations by up to one year.
    EPA promulgated the 2010 1-hour SO2 NAAQS on June 2,
2010. See 75 FR 35520 (June 22, 2010). EPA completed the first round of
designations for the 2010 1-hour SO2 NAAQS on July 25, 2013,
designating 29 areas in 16 states as nonattainment for the 2010 1-hour
SO2 NAAQS. See 78 FR 47191 (August 5, 2013). EPA based this
first round of final SO2 designations on monitored
SO2 concentrations violating the 2010 1-hour SO2
standard. Following the initial August 5, 2013, designations, three
lawsuits were filed against EPA in different U.S. District Courts,
alleging that the Agency had failed to perform a nondiscretionary duty
under the CAA by not designating all portions of the country within the
time lines set forth in section 107(d)(1)(B) of the CAA. In an effort
intended to resolve the litigation in one of those cases, EPA and the
plaintiffs, Sierra Club and the Natural Resources Defense Council,
filed a proposed consent decree with the U.S. District Court for the
Northern District of California. On March 2, 2015, the court entered
the consent decree \4\ which requires EPA to sign for publication in
the Federal Register notices of the Agency's promulgation of area
designations by three specific deadlines: July 2, 2016 (``round 2'');
December 31, 2017 (``round 3''); and December 31, 2020 (``round
4'').\5\
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    \4\ Consent Decree, Sierra Club v. McCarthy, Case No. 3:13-cv-
3953-SI (N.D. Cal. Mar. 2, 2015).
    \5\ The term ``round'' in this instance refers to which ``round
of designations.''
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    On August 21, 2015 (80 FR 51052), EPA separately promulgated air
quality characterization requirements for the 2010 1-hour
SO2 NAAQS in the Data Requirements Rule (DRR). The DRR
required state air agencies to characterize air quality, through air
dispersion modeling or monitoring, in areas associated with sources
that emitted greater than 2,000 tons per year (tpy) of SO2,
or that have otherwise been listed under the DRR by EPA or state air
agencies. In lieu of modeling or monitoring, state air agencies, by
specified dates, could elect to impose federally-enforceable emissions
limitations on those sources restricting their annual SO2
emissions to 2,000 tpy or less, or provide documentation that the
sources have been shut down. EPA expected that the information
generated by implementation of the DRR would help inform SO2
designations specified in the March 2, 2015, consent decree. EPA signed
Federal Register notices of promulgation of round 2 designations \6\

on June 30, 2016 (81 FR 45039 (July 12, 2016)), and on November 29,
2016 (81 FR 89870 (December 13, 2016)), and round 3 designations \7\ on
December 21, 2017 (83 FR 1098 (January 9, 2018)). For South Carolina,
EPA designated all counties as attainment/unclassifiable in round 3.
Because all counties in South Carolina are now designated for the 2010
1-hour SO2 NAAQS, and no DRR sources in the State opted to
monitor to inform Round 4 SO2 designations, no areas in
South Carolina will be designated in round 4.\8\ There are no
nonattainment areas in South Carolina for the 2010 1-hour
SO2 NAAQS.\9\
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    \6\ EPA and state documents and public comments related to the
round 2 final designations are in the docket at regulations.gov with
Docket ID NO. EPA-HQ-OAR-2014-0464 and at EPA's website for
SO2 designations at https://www.epa.gov/sulfur-dioxide-designations.
    \7\ EPA and state documents and public comments related to round
3 final designations are in the docket at regulations.gov with
Docket ID NO. EPA-HQ-OAR-2017-0003 and at EPA's website for
SO2 designations at https://www.epa.gov/sulfur-dioxide-designations.
    \8\ See Technical Support Document: Chapter 37 Final Round 3
Area Designations for the 2010 1-Hour SO2 Primary National Ambient
Air Quality Standard for South Carolina at https://www.epa.gov/sites/production/files/2017-12/documents/37-sc-so2-rd3-final.pdf.
See also Technical Support Document: Chapter 37 Intended Round 3
Area Designations for the 2010 1-Hour SO2 Primary National Ambient
Air Quality Standard for South Carolina at https://www.epa.gov/sites/production/files/2017-08/documents/38sc_so2_rd3-final.pdf.
    \9\ On August 5, 2013 (78 FR 47191) and effective October 4,
2013, EPA designated 29 areas in 16 states as nonattainment for the
2010 1-hour SO2 NAAQS based on violating monitors using
air quality data for the years 2009-2011, but did not, at that time,
designate other areas in the country. On July 12, 2016 (81 FR
45039), effective September 12, 2016, and December 13, 2016 (81 FR
89870), effective January 12, 2017, EPA published a final rule
establishing air quality designations for 65 areas in 24 states for
the 2010 SO2 NAAQS including seven nonattainment areas,
41 attainment/unclassifiable areas, and 17 unclassifiable areas. On
January 9, 2018 (83 FR 1098) effective April 9, 2018, EPA designated
six areas as nonattainment; 23 areas as unclassifiable; and the rest
of the areas covered by this round in all states, territories, and
tribal lands as attainment/unclassifiable. No areas in South
Carolina were designated as nonattainment in these actions. See
https://www.epa.gov/sulfur-dioxide-designations/sulfur-dioxide-designations-regulatory-actions.
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II. Relevant Factors Used To Evaluate 2010 1-Hour SO2 Interstate
Transport SIPs

    Interstate transport of SO2 is unlike the transport of
fine particulate matter (PM2.5) or ozone in that
SO2 is not a regional pollutant and does not commonly
contribute to widespread nonattainment over a large (and often multi-
state) area. The transport of SO2 is more analogous to the
transport of lead (Pb) because its properties result in localized
pollutant impacts very near the emissions source. However, ambient
concentrations of SO2 do not decrease as quickly with
distance from the source as Pb because of the properties and typical
release heights of SO2. Emissions of SO2 travel
farther and have wider ranging impacts than emissions of Pb, but do not
travel far enough to be treated in a manner similar to ozone or
PM2.5. The approaches that EPA has adopted for ozone or
PM2.5 transport are too regionally focused and the approach
for Pb transport is too tightly circumscribed to the source.
SO2 transport is therefore a unique case and requires a
different approach.
    Given the properties of SO2, EPA agrees with South
Carolina's selection of a spatial scale with dimensions from four to 50
kilometers (km) from point sources--the ``urban scale''--to assess
trends in area-wide air quality that might impact downwind states.\10\
SC DHEC selected the urban scale as appropriate for assessing trends in
both area-wide air quality and the effectiveness of large-scale
pollution control strategies at SO2 point sources. SC DHEC
supported this transport distance threshold with references to 40 CFR
58, Appendix D, Section 4.4.4(4) ``Urban scale'', which states that
measurements in this scale would be used to estimate SO2
concentrations over large portions of an urban area with dimensions
from four to 50 km. The State also notes that 50 km is the transport
distance threshold that EPA recommends for use with the air quality
dispersion model called the American Meteorological Society/
Environmental Protection Agency Regulatory Model (AERMOD). AERMOD is
EPA's preferred modeling platform for regulatory purposes (Appendix W
of 40 CFR part 51).\11\ EPA agrees with the State's selection and
application of the 50-km threshold as a reasonable distance to evaluate
emission source impacts into neighboring states and to assess air
quality monitors within 50 km of the State's border, which is discussed
further in section III.C.
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    \10\ For the definition of spatial scales for SO2,
please see 40 CFR part 58, Appendix D, section 4.4 (``Sulfur Dioxide
(SO2) Design Criteria''). For further discussion on how
EPA applies these definitions with respect to interstate transport
of SO2, see EPA's notice of proposed rulemaking on
Connecticut's SO2 transport SIP. 82 FR 21351, 21352,
21354 (May 8, 2017).
    \11\ EPA established a non-binding technical assistance document
to assist states and other parties in their efforts to characterize
air quality through air dispersion modeling for sources that emit
SO2 titled, ``SO2 NAAQS Designations Modeling
Technical Assistance Document. This draft document was first
released in spring 2013. Revised drafts were released in February
and August of 2016 (see https://www.epa.gov/sites/production/files/2016-06/documents/so2modelingtad.pdf).
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    As discussed in sections III.C and III.D, EPA first reviewed the
State's analysis to assess how the State evaluated the transport of
SO2 to other states, the types of information used in the
analysis, and the conclusions drawn by the State. EPA then conducted a
weight of evidence analysis based on a review of the State's submission
and other available information, including SO2 air quality
and available source modeling for states within 50 km of the South
Carolina border.\12\
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    \12\ This proposed approval action is based on the information
contained in the administrative record for this action, and does not
prejudge any future EPA action that may make other determinations
regarding the air quality status in South Carolina and downwind
states. Any such future action, such as area designations under any
NAAQS, will be based on their own administrative records and the
EPA's analyses of information that becomes available at those times.
Future available information may include, and is not limited to,
monitoring data and modeling analyses conducted pursuant to EPA's
DRR and information submitted to EPA by states, air agencies, and
third-party stakeholders such as citizen groups and industry
representatives.
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III. South Carolina's SIP Submission and EPA's Analysis

A. State Submission

    On June 25, 2018, SC DHEC submitted a revision to the South
Carolina SIP addressing prongs 1 and 2 of CAA section
110(a)(2)(D)(i)(I) for the 2010 1-hour SO2 NAAQS. South
Carolina conducted a weight of evidence analysis to examine whether
SO2 emissions from the State adversely affect attainment or
maintenance of the 2010 1-hour SO2 NAAQS in downwind states.
    SC DHEC reviewed the following information to support its
conclusion that South Carolina does not significantly contribute to
nonattainment or interfere with maintenance of the 2010 1-hour
SO2 NAAQS in downwind states: Trends in SO2
design values (DVs) \13\ at the State's air quality monitors from 2008-
2017; highest monitored SO2 DVs for monitors with complete,
quality-assured data and located within South Carolina and within
Florida, Georgia, and North Carolina; SO2 emissions trends
both statewide (for the years 2008, 2011, and 2014) and for the State's
title V sources (for the years 2008-2016); available SO2
modeling data for the State's round 3 DRR-subject sources; and State
and federal regulations and State statutes that establish requirements
for sources

of SO2 emissions. South Carolina noted that federal
regulations and competition from lower natural gas prices resulted in
four coal-fired electric generating units (EGUs) within the State
either shutting down or switching to cleaner fuels. The State
identified these units and summarized the history of the shutdowns and
switches to cleaner fuels. South Carolina also included SO2
emissions trends for the Southeast from 2000-2016 and noted that there
is a consistent downward trend.
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    \13\ A ``Design Value'' is a statistic that describes the air
quality status of a given location relative to the level of the
NAAQS. The DV for the primary 2010 1-hour SO2 NAAQS is
the 3-year average of annual 99th percentile daily maximum 1-hour
values for a monitoring site. The interpretation of the primary 2010
1-hour SO2 NAAQS including the data handling conventions
and calculations necessary for determining compliance with the NAAQS
can be found in Appendix T to 40 CFR part 50.
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    Based on this weight of evidence analysis, the State concluded that
emissions within South Carolina will not contribute significantly to
nonattainment or interfere with maintenance of the 2010 1-hour
SO2 NAAQS in any other state. The State based its
conclusions for Prong 1 on the actual and projected downward trends of
SO2 emissions in South Carolina, trends in SO2
DVs for South Carolina's monitors and other states' monitors within 50
km of the South Carolina border, DRR modeling results, and established
federal and State control measures affecting SO2. The State
based its conclusions for Prong 2 on emissions trends of SO2
in South Carolina and in the Southeast and established federal and
State control measures which reduce SO2 emissions. EPA's
evaluation of South Carolina's submission is detailed in sections
III.B, C, and D.

B. EPA's Evaluation Methodology

    EPA believes that a reasonable starting point for determining which
sources and emissions activities in South Carolina are likely to impact
downwind air quality in other states with respect to the 2010 1-hour
SO2 NAAQS is by using information in EPA's National
Emissions Inventory (NEI).\14\ The NEI is a comprehensive and detailed
estimate of air emissions for criteria pollutants, criteria pollutant
precursors, and hazardous air pollutants from air emissions sources
that is updated every three years using information provided by the
states and other information available to the EPA. EPA used the 2014
NEI (version 2), the most recently available, complete, and quality
assured dataset of the NEI. Table 1 shows that point sources in South
Carolina contribute approximately 89 percent of the State's total
SO2 emissions, followed by nonpoint sources at six percent
and fires at four percent.
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    \14\ EPA's NEI is available at https://www.epa.gov/air-emissions-inventories/national-emissions-inventory.

 Table 1--Summary of 2014 NEI (Version 2) SO2 Data for South Carolina by
                             Source Category
------------------------------------------------------------------------
                                                            Percent of
                Category                     Emissions       total SO2
                                               (tpy)         emissions
------------------------------------------------------------------------
Point...................................       46,913.26              89
Nonpoint................................        2,986.99               6
Fire....................................        2,300.06               4
Onroad..................................          546.07               1
Nonroad.................................           47.85               0
                                         -------------------------------
    SO2 Emissions Total.................       52,794.23             100
------------------------------------------------------------------------

    SC DHEC provided NEI data for the years 2008, 2011, and 2014, which
showed a decrease in SO2 emissions in the State of
approximately 73 percent from 2008 to 2014. SC DHEC notes in its
submission that the largest sources of SO2 emissions in
South Carolina are power plants and other industrial facilities that
burn fossil fuels. According to the NEI data in the State's submission
and the 2014 NEI version 2 (shown in Table 2), the majority of
SO2 emissions in South Carolina originate from fuel
combustion at point sources.\15\ In 2014, the total SO2
emissions from fuel combustion point sources in South Carolina
comprised approximately 72 percent of the total SO2
emissions in the State. Because emissions from the other listed source
categories are more dispersed throughout the State, those categories
are less likely to cause high ambient concentrations when compared to a
point source on a ton-for-ton basis. Therefore, EPA believes that it is
appropriate to focus the analysis on SO2 emissions from fuel
combustion at South Carolina's point sources which are located within
the ``urban scale,'' i.e., within 50 km of one or more state borders.
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    \15\ Residential fuel combustion is considered a nonpoint
source, and thus, residential fuel combustion data is not included
in the point source fuel combustion data and related calculations.

 Table 2--Summary of 2014 NEI (Version 2) SO2 Data for South Carolina by
                              Source Types
------------------------------------------------------------------------
                                                             Emissions
                        Category                               (tpy)
------------------------------------------------------------------------
Fuel Combustion: EGUs (All Fuel Types)..................       27,799.38
Fuel Combustion: Industrial Boilers/Internal Combustion        10,243.87
 Engines (All Fuel Types)...............................
Fuel Combustion: Commercial/Institutional (All Fuel                41.40
 Types).................................................
Fuel Combustion: Residential (All Fuel Types)...........          128.74
Industrial Processes (All Categories)...................        8,963.50
Mobile Sources (All Categories).........................        2,602.33
Fires (All Types).......................................        2,363.13
Waste Disposal..........................................          648.48
Solvent Processes.......................................            0.12
Miscellaneous (Non-Industrial)..........................            3.30
                                                         ---------------
    SO2 Emissions Total.................................       52,794.23
------------------------------------------------------------------------

    EPA's current implementation strategy for the 2010 1-hour
SO2 NAAQS includes the flexibility to characterize air
quality for stationary sources via either data collected at ambient air
quality monitors sited to capture the points of maximum concentration,
or air dispersion modeling. EPA's assessment of SO2
emissions from fuel combustion at South Carolina's point sources
located within approximately 50 km of another state and their potential
impact on neighboring states is informed by all available data at the
time of this rulemaking.\16\
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    \16\ EPA notes that the evaluation of other states' satisfaction
of section 110(a)(2)(D)(i)(I) for the 2010 1-hour SO2
NAAQS can be informed by similar factors found in this proposed
rulemaking, but may not be identical to the approach taken in this
or any future rulemaking for South Carolina, depending on available
information and state-specific circumstances.
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    As discussed in section I.B., many air agencies used air dispersion
modeling to characterize air quality in the vicinity of large
SO2 emitting sources to identify the maximum 1-hour
SO2 concentrations in ambient air which informed EPA's round
2 and 3 SO2 designations. These designations were based on
EPA's application of the nationwide analytical approach to, and
technical assessment of, the weight of evidence for each area,
including but not limited to available air quality monitoring data and
air quality modeling results. The 2010 1-hour SO2

standard is violated at an ambient air quality monitoring site (or in
the case of dispersion modeling, at an ambient air quality receptor
location) when the 3-year average of the annual 99th percentile of the
daily maximum 1-hour average concentrations exceeds 75 ppb, as
determined in accordance with Appendix T of 40 CFR part 50. EPA's
preferred modeling platform for regulatory purposes is AERMOD (Appendix
W of 40 CFR part 51).\17\ In most modeling analyses, the impacts of the
actual emissions for one or more of the recent 3-year periods (e.g.,
2012-2014, 2013-2015, 2014-2016) were considered, and in some cases the
modeling was of currently effective limits on allowable emissions in
lieu of or as a supplement to modeling of actual emissions.
---------------------------------------------------------------------------

    \17\ EPA established a draft non-binding technical assistance
document to assist states and other interested parties in their
efforts to characterize air quality through air dispersion modeling
for sources that emit SO2 titled, ``SO2 NAAQS
Designations Modeling Technical Assistance Document.'' This draft
document was first released in spring 2013. Revised drafts were
released in February and August of 2016 (see https://www.epa.gov/sites/production/files/2016-06/documents/so2modelingtad.pdf).
---------------------------------------------------------------------------

    The available air dispersion modeling of large SO2
sources can support transport related conclusions about whether sources
in one state are potentially causing or contributing to violations of
the 2010 1-hour SO2 standard in other states. While AERMOD
was not designed specifically to address interstate transport, the 50-
km distance that EPA recommends for use with AERMOD aligns with the
urban monitoring scale, and thus, EPA believes that the use of AERMOD
provides a reliable indication of air quality for transport purposes.
    As described in this section, EPA proposes to conclude that an
assessment of South Carolina's satisfaction of the prong 1 and 2
requirements under section 110(a)(2)(D)(i)(I) of the CAA for the 2010
1-hour SO2 NAAQS may be reasonably based upon evaluating the
downwind impacts of SO2 emissions from fuel combustion at
South Carolina's point sources located within approximately 50 km of
another state and upon any regulations intended to address fuel
combustion at South Carolina's point sources.

C. EPA's Prong 1 Evaluation--Significant Contribution to Nonattainment

    Prong 1 of the good neighbor provision requires states' plans to
prohibit emissions that will significantly contribute to nonattainment
of a NAAQS in another state. SC DHEC confirms in its submission that
South Carolina's SIP contains adequate provisions to prevent sources
and other types of emissions activities within the State from
contributing significantly to nonattainment in any other state with
respect to the 2010 1-hour SO2 standard. To evaluate South
Carolina's satisfaction of prong 1, EPA assessed the State's
implementation plan with respect to the following factors: (1)
SO2 ambient air quality and emissions trends for South
Carolina and neighboring states; (2) potential ambient impacts of
SO2 emissions from certain facilities in South Carolina on
neighboring states based on available air dispersion modeling results;
(3) State statutes and SIP-approved regulations that address
SO2 emissions; and (4) federally enforceable regulations
that reduce SO2 emissions. A detailed discussion of South
Carolina's SIP submission with respect to each of these factors
follows.\18\ EPA proposes that these factors, taken together, support
the Agency's proposed determination that South Carolina's SIP
adequately prohibits emissions that will significantly contribute to
nonattainment of the 2010 1-hour SO2 NAAQS in another state.
EPA's proposed conclusion is based, in part, on the fact that the
Agency does not have information indicating that there are violations
of the 2010 1-hour SO2 NAAQS in the surrounding states. In
addition, the downward trends in SO2 emissions and DVs for
air quality monitors in the State, combined with federal and State
regulations and statutes affecting SO2 emissions of South
Carolina's sources, further support EPA's proposed conclusion.
---------------------------------------------------------------------------

    \18\ EPA has reviewed South Carolina's submission, and where new
or more current information has become available, is including this
information as part of the Agency's evaluation of this submission.
---------------------------------------------------------------------------

1. SO2 Air Dispersion Modeling
a. State Submission
    In its June 25, 2018, SIP revision, SC DHEC summarized how each of
the State's sources subject to the DRR elected to comply with this rule
by either taking a federally-enforceable limit or using either modeling
or monitoring to characterize SO2 air quality around the
source. Of the eight sources in the State subject to the DRR, three
accepted federally-enforceable permit limits and five sources conducted
dispersion modeling.\19\ SC DHEC provided a summary of the air
dispersion modeling results for the five modeled sources: Century
Aluminum of South Carolina \20\ (Century Aluminum); International
Paper-Eastover Mill (IP Eastover); Resolute FP US INC (Resolute);
Santee Cooper Cross Generating Station (Santee Cooper Cross); and SCE&G
Wateree Station (SCE&G Wateree). IP Eastover and SCE&G Wateree were
modeled together. Of these five sources, one source (Resolute) is
within 50 km of another state (North Carolina) at approximately 7 km
using the nearest property boundary to North Carolina and modeled a
maximum 2010 1-hour SO2 DV of 69 ppb. SC DHEC notes that
Resolute used a modeling grid which extended approximately 4 km into
North Carolina. A summary of the modeling results for Resolute,
including supplemental data EPA has reviewed as part of the Agency's
analysis, is shown in Table 3 of section III.C.1.b of this action.
---------------------------------------------------------------------------

    \19\ South Carolina's DRR sources which accepted federally-
enforceable permit limits to exempt out of the DRR requirements are:
Duke Energy Carolinas LLC--W.S. Lee Steam Station; South Carolina
Electric & Gas (SCE&G) McMeekin Station; and WestRock CP LLC
(formerly RockTenn). See Docket ID No. EPA-HQ-OAR-2017-0003. Thus,
there is no available air dispersion modeling under the DRR for
these sources.
    \20\ Century Aluminum was formerly known as Alumax of South
Carolina.
---------------------------------------------------------------------------

b. EPA Analysis
    For the SO2 air dispersion modeling factor, EPA
evaluated the DRR modeling data in South Carolina's June 25, 2018,
submission for sources in the State and supplemented this data with
available, existing DRR modeling results for sources in the adjacent
states of Georgia and North Carolina that are within 50 km of the South
Carolina border.\21\ The purpose of evaluating modeling results in
adjacent states within 50 km of the South Carolina border is to
ascertain whether these areas are attaining the 2010 1-hour
SO2 standard and, if not, whether any nearby sources in
South Carolina are contributing to a NAAQS violation. In addition, EPA
identified South Carolina SO2 emission sources emitting
greater than 100 tons of SO2 in 2017 that are not subject to
the DRR and are located up to 50 km from South Carolina's border to
evaluate whether the SO2 emissions from these sources could
interact with SO2 emissions from the nearest source in a
neighboring state

in such a way as to contribute significantly to nonattainment in that
state.
---------------------------------------------------------------------------

    \21\ Appendix A.1--titled, ``AERMOD (AMS/EPA Regulatory Model)''
of Appendix W to 40 CFR part 51--is appropriate for SO2
in instances where steady-state assumptions for transport distances
up to 50 km occur. While not designed specifically to address
interstate transport, the 50-km distance which EPA recommends for
use with AERMOD aligns with the urban monitoring scale, and thus,
EPA believes that the use of AERMOD provides a reliable indication
of SO2 air quality for transport purposes.
---------------------------------------------------------------------------

    Table 3 provides a summary of the modeling results for Resolute,
the one modeled DRR source in South Carolina which is located within 50
km of another state (North Carolina). The modeling analyses for
Resolute resulted in no modeled violations of the 2010 1-hour
SO2 NAAQS within the 50-km area surrounding the facility and
no violations of the standard within the modeling domain which extends
into North Carolina. All other areas within 50 km of Resolute are
contained within South Carolina's borders. As a result, no further
analysis of any other neighboring states is necessary for assessing the
impacts of the interstate transport of SO2 pollution from
Resolute.
    Table 4 provides a summary of the modeling results for DRR sources
in other neighboring states which are located within 50 km of South
Carolina and which elected to provide air dispersion modeling under the
DRR: Three sources in Georgia (Georgia Power Company--Plant McIntosh
(Plant McIntosh), Georgia-Pacific Consumer Products--Savannah River
Mill (Savannah River Mill), International Paper--Savannah (IP-
Savannah)) \22\ and two sources in North Carolina (Allen Steam
Station--Duke Energy Carolinas, LLC (Duke-Allen) \23\ and Duke Energy's
Marshall Steam Station (Duke-Marshall)).\24\ The predicted maximum
impacts from the model did not violate the 2010 1-hour SO2
NAAQS for any of the five sources.\25\
---------------------------------------------------------------------------

    \22\ Georgia Power's Plant Kraft is a DRR source located less
than 5 km from the South Carolina border which has shut down as of
October 13, 2015, and the operating permit was formally revoked on
November 9, 2016. The DRR modeling results for Georgia's DRR round 3
sources may be found at: https://www.epa.gov/sites/production/files/2017-08/documents/10_ga-so2-rd3-final.pdf.
    \23\ The Duke-Allen facility did not meet the DRR emission
threshold of 2,000 tons or more annually. However, North Carolina
elected to characterize the area around the source through air
dispersion modeling.
    \24\ Given that distances are approximate, the Duke-Marshall
facility is included in Table 4 with an approximate distance of 53
km from the South Carolina border.
    \25\ Georgia's Plant McIntosh and Savannah River Mill were
modeled together as shown in Table 4.

                                 Table 3--South Carolina Sources With DRR Modeling Located Within 50 km of Another State
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Approximate  distance                                2010 1-hour
            DRR source                      County            from  source to      Other facilities included   SO2 Model DV     Model grid extends into
                                                               adjacent state            in  modeling              (ppb)            another state?
--------------------------------------------------------------------------------------------------------------------------------------------------------
Resolute..........................  York.................  7 km.................  Yes--Duke-Allen (NC);                 69 *  Yes--into NC (western
                                                                                Winthrop University;                        portion of Union County
                                                                                General Chemicals, LLC;                     in North Carolina)
                                                                                Guardian Industries;
                                                                                Spring Industries--Leroy
                                                                                Plant.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Resolute's 2010 1-hour SO2 modeled DV is based on 2012-2014 actual emissions for Resolute and all North Carolina permitted facilities within 50 km of
  the source, and allowable emissions for all South Carolina permitted facilities within 50 km of the source.

                                 Table 4--Other State's Sources with DRR Modeling Located Within 50 km of South Carolina
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                           Approximate
                                                          distance from         Other facilities      2010 1-hour SO2 model DV   Model grid extends into
           DRR source                County (state)      source to South      included in modeling              (ppb)                another state?
                                                         Carolina border
--------------------------------------------------------------------------------------------------------------------------------------------------------
Plant McIntosh (Modeled with      Effingham (GA).....  Less than 5 km.....  Effingham County Power    71.6 for both Plant       Yes--into SC (western
 Savannah River Mill).                                                       (GA); SCE&G-Jasper        McIntosh and Savannah     portion of Jasper
                                                                             Generating Station        River Mill (based on      County, SC).
                                                                             (SC)--(based on           2012-2014 actual
                                                                             allowable/potential to    emissions for Plant
                                                                             emit (PTE) emissions).    McIntosh).
Savannah River Mill (Modeled      Effingham (GA).....  Less than 5 km.....  Effingham County Power    71.6 for both Plant       Yes--into SC (western
 with Plant McIntosh).                                                       (GA); SCE&G-Jasper        McIntosh and Savannah     portion of Jasper
                                                                             Generating Station        River Mill *.             County, SC).
                                                                             (SC)--.
IP--Savannah....................  Chatham (GA).......  Less than 5 km.....  None....................  66 (based on 2011-2013    Yes--into SC (western
                                                                                actual and allowable/     portion of Jasper
                                                                                PTE emissions).           County, SC).
Duke-Allen......................  Gaston (NC)........  5 km...............  Duke-Marshall...........  46.6 (based on 2013-2015  Yes--into SC (York
                                                                                actual SO emissions).     County and portions of
                                                                                Cherokee, Union,
                                                                                Chester, Lancaster, and
                                                                                Chesterfield Counties
                                                                                in SC).
Duke-Marshall...................  Catawba (NC).......  53 km..............  Duke-Allen..............  68 (based on 2013-2015    Yes--into SC (small
                                                                                actual SO emissions).     portion of York and
                                                                                Cherokee Counties in
                                                                                SC).
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Savannah River Mill's 2010 1-hour SO2 modeled DV is based on 2012-2014 actual emissions for three primary power boilers and allowable/PTE emissions
  for 13 emissions units at Savannah River Mill. (For more details, see pp. 67-68 of EPA's Technical Support Document: Chapter 10 Proposed Round 3 Area
  Designations for the 2010 1-Hour SO2 Primary National Ambient Air Quality Standard for Georgia located at https://www.epa.gov/sites/production/files/2017-08/documents/10_ga-so2-rd3-final.pdf.)

    As mentioned previously, EPA finds that it is appropriate to
examine the impacts of SO2 emissions from stationary sources
in South Carolina in distances ranging from zero km to 50 km from the
sources. Therefore, in addition to those sources addressed in Tables 3
and 4 of this action, EPA assessed the potential impacts of
SO2 emissions from stationary sources not subject to the DRR
and located up to 50 km from South Carolina's borders to evaluate
trends in area-wide air quality. Table 5 lists sources in South
Carolina not characterized under the DRR \26\ that emitted greater than
100 tpy of SO2 in 2017 and are located within 50 km of the
State's border. All three of the identified sources were located along
the border of South Carolina and North Carolina.
---------------------------------------------------------------------------

    \26\ One source, Westrock CP, LLC accepted a permit limit to
exempt out of being subject to the DRR.

                            Table 5--South Carolina Non-DRR SO2 Sources Emitting Greater Than 100 tpy Near Neighboring States
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Approximate
                                             2017 Annual     Approximate                                  distance to
                                            SO2 emissions    distance to                                    nearest       Nearest neighboring state SO2
          South Carolina source                (tons)      South Carolina   Closest neighboring state     neighboring     source & 2017 emissions (>100
                                                             border (km)                                   state SO2              tons of SO2)
                                                                                source (km)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Milliken & Co. Magnolia Plant............             697             5.5  North Carolina.............              23  Duke Energy Carolinas, LLC--
                                                                                Cliffside Steam Station (858
                                                                                tons).
Guardian Industries......................             103            22.5  North Carolina.............              53  Duke--Allen (354 tons).
WestRock CP LLC..........................           1,480              44  North Carolina.............              68  Pilkington North America, Inc.
                                                                                (Pilkington) (383 tons).
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Currently, EPA does not have monitoring or modeling data suggesting
that North Carolina is impacted by SO2 emissions from the
Milliken & Co. Magnolia Plant or WestRock CP LLC. With regard to the
WestRock facility, EPA believes that the 68-km distance between the
WestRock facility in South Carolina and the Pilkington facility, the
nearest source in North Carolina with SO2 emissions greater
than 100 tpy, makes it unlikely that SO2 emissions from
WestRock could interact with SO2 emissions from Pilkington
in such a way as to contribute significantly to nonattainment in North
Carolina.
    Allowable SO2 emissions from the Guardian Industries
facility were included in South Carolina's modeling of the Resolute DRR
source,\27\ which was addressed in Table 3. This modeling did not show
any violations of the 2010 1-hour SO2 NAAQS within 50 km of
the South Carolina border, and thus, indicates that Guardian Industries
does not significantly contribute to nonattainment of the 2010 1-hour
SO2 NAAQS in any other state.
---------------------------------------------------------------------------

    \27\ See pp.81-82 and p.92 of EPA's Technical Support Document:
Chapter 37 Intended Round 3 Area Designations for the 2010 1-Hour
SO2 Primary National Ambient Air Quality Standard for
South Carolina located at: https://www.epa.gov/sites/production/files/2017-08/documents/38sc_so2_rd3-final.pdf.
---------------------------------------------------------------------------

    The modeling results in Tables 3 and 4 predict no violations of the
2010 1-hour SO2 NAAQS within 50 km of the South Carolina
border, and thus, EPA believes that these results, weighed along with
the other factors in this document and the Agency's analysis of the
South Carolina sources addressed in Table 5, support EPA's proposed
conclusion that sources in South Carolina do not significantly
contribute to nonattainment of the 2010 1-hour SO2 NAAQS in
any other state.
2. SO2 Emissions Trends
a. State Submission
    As part of its SIP submission, South Carolina presented
SO2 emissions trends both statewide (for the years 2008-
2014) and for the State's title V sources (for the years 2008-2016).
Statewide SO2 emissions have decreased by approximately 73
percent from 197,136 tpy in 2008 to 52,782 tpy in 2014,\28\ and
SO2 emissions from South Carolina's title V sources have
decreased by approximately 88 percent from 191,058 tpy in 2008 to
22,422 tpy in 2016.
---------------------------------------------------------------------------

    \28\ EPA notes there is a slight difference in the 2014 NEI
value for South Carolina's SO2 emissions between what SC
DHEC provided based on version 1 of the NEI (52,782 tpy) and the
value that EPA relied upon from version 2 of the NEI (52,794 tpy).
---------------------------------------------------------------------------

b. EPA Analysis
    EPA reviewed the statewide and title V source SO2
emissions trends data provided by South Carolina and agrees that the
data show a significant decline (73 and 88 percent, respectively, as
noted earlier). Based on the emissions trends information in South
Carolina's submission, EPA believes that these declining SO2
emissions may suggest that South Carolina does not significantly
contribute to nonattainment of the 2010 1-hour SO2 NAAQS in
any other state, particularly given that SO2 emissions
limits for South Carolina's title V sources are federally enforceable
conditions established in title V permits.
3. SO2 Ambient Air Quality
a. State Submission
    In its June 25, 2018, SIP submission, SC DHEC illustrated
graphically that the DVs from 2008 through 2017 at nine out of 10
monitors in South Carolina in EPA's Air Quality System (AQS) \29\
(``AQS monitors'') have remained well below the 2010 1-hour
SO2 NAAQS since 2008.\30\ The one monitor with data above
the 2010 1-hour SO2 NAAQS from 2008 to 2010 attained the
standard in 2011, and the DVs for this monitor sharply decreased
between 2011 to 2017. SC DHEC notes that the State's AQS monitors are
all attaining the 2010 1-hour SO2 NAAQS and the DVs at these
monitors show a consistent downward trend. In addition, SC DHEC noted
that the highest monitored DV in the State for the 2014-2016 time
period is 29 ppb, which is 39 percent of the 2010 1-hour SO2
NAAQS.
---------------------------------------------------------------------------

    \29\ EPA's AQS contains ambient air pollution data collected by
EPA, state, local, and tribal air pollution control agencies. See
https://www.epa.gov/air-trends/air-quality-design-values.
    \30\ Three of the 10 monitors located in South Carolina shown in
the figure on p.8 of the State's June 25, 2018, SIP submission
(named ``DHEC,'' ``Powdersville,'' and ``York'') have shut down.
---------------------------------------------------------------------------

    SC DHEC also included a figure displaying AQS monitors located in
South Carolina and in other states within 50 km of the South Carolina
border. This figure depicts a total of 14 AQS monitors (seven South
Carolina monitors with DVs; four monitors in other states with DVs; and
three AQS monitors in North Carolina that were established to
characterize the air quality around specific sources subject

to EPA's DRR to inform the Agency's future round 4 designations for the
2010 1-hour SO2 NAAQS in lieu of modeling (hereinafter
referred to as ``DRR monitors''). Of the 11 monitors with DVs, 10
monitors have had DVs at or just below the 2010 1-hour SO2
NAAQS since the 2009-2011 DV time period, and all DVs have been below
the standard since the 2013-2015 DV period. Two of the North Carolina
DRR monitors within 50 km of South Carolina have annual 99th percentile
1-hour SO2 concentrations above the 2010 1-hour
SO2 NAAQS for 2017. SC DHEC also provided the highest
monitored SO2 DVs for the years 2014-2016 at AQS monitors
anywhere in Florida, Georgia, and North Carolina (i.e., 81, 60, and 23
ppb, respectively).\31\ SC DHEC notes that the nearest SO2
nonattainment area is the Nassau County partial area \32\ in Florida,
which is over 150 km from the South Carolina border.
---------------------------------------------------------------------------

    \31\ EPA notes that Florida is not adjacent to South Carolina.
    \32\ The term ``partial area'' in this instance refers to when
EPA has designated a portion a county nonattainment for a NAAQS.
---------------------------------------------------------------------------

b. EPA Analysis
    Since the time of development of South Carolina's SIP submission,
certified AQS monitoring data has become available for South Carolina
and the surrounding states to inform the 2015-2017 DVs. EPA has
summarized the DVs from 2012 to 2017 for AQS monitors in South Carolina
within 50 km of another state in Table 6 and for AQS monitors in the
surrounding states of Georgia and North Carolina within 50 km of South
Carolina in Table 7 using relevant data from EPA's AQS DV reports for
recent and complete 3-year periods.

                         Table 6--2010 1-Hour SO2 DVs for AQS Monitors in South Carolina Within 50 km of Another State's Border
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                        AQS site    2010-2012    2011-2013    2012-2014    2013-2015    2014-2016    2015-2017    Approximate  distance
               County                     code       DV (ppb)     DV (ppb)     DV (ppb)     DV (ppb)     DV (ppb)     DV (ppb)    to state  border (km)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Greenville..........................    450450008         * ND         * ND         * ND            3            2            2  37 (NC)
Oconee..............................    450730001         * ND         * ND         * ND            3            2            2  3 (GA)
--------------------------------------------------------------------------------------------------------------------------------------------------------
* ND indicates ``No Data'' due to monitor startup or shutdown (operated less than three years), data quality issues, or incomplete data.

    As shown in Table 6, the 2015, 2016, and 2017 DVs for the two
monitoring sites in South Carolina (Greenville and Oconee Counties)
within 50 km of another state's border have remained well below the
2010 1-hour SO2 NAAQS.
    Table 7 shows that there are three AQS monitors in Georgia (Chatham
and Richmond Counties) and one AQS monitor in North Carolina
(Mecklenberg County) with 3-year DVs which are located within 50 km of
the South Carolina border. Currently, there are no AQS monitors
indicating a violation of the 2010 1-hour SO2 NAAQS located
within 50 km of South Carolina in the surrounding states of Georgia and
North Carolina. Further, the DVs for the monitors in Table 7 have
declined since 2013 for Georgia's Chatham County monitor with AQS site
code 130511002 and since 2012 for North Carolina's Mecklenberg County
monitor. For Georgia's Richmond County monitor and Chatham County
monitor with AQS site code 130511002, the DVs similarly show a downward
trend, excluding those time periods for which there is no data to
determine a DV. Also, the most recent DVs for 2015-2017 are well below
the 2010 1-hour SO2 NAAQS. Thus, EPA believes that these
data support EPA's proposed conclusion that South Carolina does not
significantly contribute to nonattainment of the 2010 1-hour
SO2 NAAQS in any other state.

                           Table 7--2010 1-Hour SO2 DVs for AQS Monitors Within 50 km of South Carolina in Surrounding States
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Approximate
               State                        County           AQS site   2010-2012  2011-2013  2012-2014  2013-2015  2014-2016  2015-2017  distance to SC
                                                               code      DV (ppb)   DV (ppb)   DV (ppb)   DV (ppb)   DV (ppb)   DV (ppb)    border (km)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Georgia...........................  Chatham..............    130511002         68         79         78         70         52         48               3
                                    Chatham..............    130510021         74         66       * ND       * ND       * ND         32               2
                                    Richmond.............    132450091       * ND       * ND       * ND         61         60         52               6
North Carolina....................  Mecklenberg..........    371190041         14         10          7          7          5          5              20
--------------------------------------------------------------------------------------------------------------------------------------------------------
* ND indicates ``No Data'' due to monitor startup or shutdown (operated less than three years), data quality issues, or incomplete data.

    As previously discussed, EPA's definitions of spatial scales for
SO2 monitoring networks indicate that distances up to 50 km
from a stationary source would be useful for assessing trends in area-
wide air quality. Thus, EPA also evaluated monitoring data provided to
date for DRR monitors located in states adjacent to South Carolina
within 50 km of the State's border. These DRR monitors do not have
three or more years of complete data to determine the DVs for these
monitors. However, EPA evaluated the available, annual 99th percentile
SO2 concentration data for these monitors.
    No sources in South Carolina elected to establish monitors under
the DRR. However, Table 8 lists three DRR sources in North Carolina
within 50 km of the South Carolina border which elected to establish
SO2 monitors to characterize the air quality in the
associated source areas. The Buncombe County monitor in North Carolina
was sited in the vicinity of the Asheville Steam Electric Plant--Duke
Energy Progress, Inc (Duke-Asheville), a DRR source. Though a single
maximum 1-hour concentration is not directly comparable to the 2010 1-
hour SO2 NAAQS, which is in the form of the 3-year average
of the 99th percentile of

daily maximum 1-hour SO2 values, EPA notes that the highest
concentration observed at the Buncombe County monitor in 2017 was 16.6
ppb, which is approximately 78 percent below the level of the 2010 1-
hour SO2 NAAQS. The other two DRR monitors in North Carolina
within 50 km of South Carolina--the Brunswick and Haywood County
monitoring sites--both exceeded the 2010 1-hour SO2 NAAQS
based on one year of complete data for 2017. For 2018, only the Haywood
County monitoring site exceeded the 2010 1-hour SO2 NAAQS.
The Brunswick and Haywood County monitoring sites are sited in the area
of maximum concentration for the DRR sources named CPI USA North
Carolina--Southport Plant (CPI) and Evergreen Packaging Group- Canton
Mill (Evergreen), respectively.
    EPA evaluated whether there are any sources in South Carolina
within 50 km of the State's border which could potentially be
contributing to the exceedances in 2017 and 2018 at the Brunswick
County and Haywood County monitors in North Carolina. With respect to
the Haywood County monitor, there is only one source in South Carolina
within 50 km of the State's border in the direction of the Haywood
County monitor. This source, Milliken Enterprise Plant, is located
approximately 12.5 km from the South Carolina border and emitted 4.25,
4.25, and 0.05 tons of SO2 in 2015, 2016, and 2017,
respectively. EPA believes that the Milliken Enterprise Plant is not
contributing to the exceedances at the Haywood County monitor due to
the source's distance of approximately 72.5 km from the monitor and the
declining SO2 emissions trend from 2015 to 2017. With
respect to the Brunswick County monitor, there are two sources in South
Carolina within 50 km of the State's border in the direction of the
Brunswick County monitor. The two sources, Horry County Solid Waste
Authority and Santee Cooper Myrtle Beach, are located approximately 31
km and 37 km, respectively, from the South Carolina border in the
direction of the Brunswick County monitor. The Horry County Solid Waste
Authority emitted 13.12, 13.12, and 12.88 tons of SO2 in
2015, 2016, and 2017, respectively. The Santee Cooper Myrtle Beach
facility emitted 0.02, 0.01, and 0.03 tons of SO2 in 2015,
2016, and 2017, respectively. EPA believes that the Horry County Solid
Waste Authority and the Santee Cooper Myrtle Beach facility are not
contributing to the exceedances at the Brunswick County monitor due to
the sources' distances of approximately 79 km and 85 km, respectively,
from the monitor. Thus, after careful review of the State's assessment,
supporting documentation, available monitoring data, and EPA's analysis
suggesting that there are no sources in South Carolina within 50 km of
the Brunswick and Haywood County DRR monitors which could be
contributing to the exceedances at the Brunswick and Haywood County DRR
monitors, EPA proposes to conclude that these monitoring data do not
provide evidence of South Carolina contributing significantly to 2010
1-hour SO2 violations in the neighboring states.

 Table 8--2010 1-Hour SO2 99th Percentile Concentrations for Round 4 DRR Monitors Within 50 km of South Carolina
                                          Located in Surrounding States
----------------------------------------------------------------------------------------------------------------
                                                                     2017 99th       2018 99th
                                     Round 4                        percentile      percentile      Approximate
        County (state)          monitored source   AQS site code   concentration   concentration  distance to SC
                                                                       (ppb)           (ppb)        border (km)
----------------------------------------------------------------------------------------------------------------
Buncombe (NC).................  Duke-Asheville..       370210037            16.6             9.8              32
Brunswick (NC)................  CPI.............       370190005            82.5            55.1              50
Haywood (NC)..................  Evergreen.......       370870013           206.8           213.4              48
----------------------------------------------------------------------------------------------------------------

4. SIP-Approved Regulations and State Statutes Addressing
SO2 Emissions
a. State Submission
    South Carolina identified State statutes and SIP-approved measures
which help ensure that SO2 emissions in the State do not
significantly contribute to nonattainment of the 2010 1-hour
SO2 NAAQS in any other state. SC DHEC lists the following
SIP-approved South Carolina regulations which establish emission limits
and other control measures for SO2: Regulation 61-62.5,
Standard No. 7, Prevention of Significant Deterioration; Regulation 61-
62.5, Standard No. 7.1, Nonattainment New Source Review; Regulation 61-
62.96, Nitrogen Oxides (NOX) and Sulfur Dioxide
(SO2) Budget Trading Program; Regulation 61-62.97, Cross-
State Air Pollution Rule (CSAPR) Trading Program; and Regulation 61-
62.1, Definitions and General Requirements. In addition, SC DHEC
promulgated Regulation 61-62.72, Acid Rain, to comply with the EPA's
Acid Rain Program, enacted to reduce acid deposition by reducing
SO2 and NOX emissions from fossil fuel-fired
power plants. SC DHEC also notes that South Carolina's Pollution
Control Act, SC Code Section 48-1-10 et seq., and State Agency Rule
Making and Adjudication of Contested Cases, SC Code Section 1-23-10 et
seq., provide for control of SO2 emissions in the State.\33\
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    \33\ These South Carolina statutes are not approved into the
State's implementation plan.
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b. EPA Analysis
    EPA believes that South Carolina's statutes and SIP-approved
measures which establish emission limits, permitting requirements, and
other control measures for SO2 effectively address emissions
of SO2 from sources in the State. For the purposes of
ensuring that SO2 emissions at new major sources or major
modifications at existing major sources in South Carolina do not
contribute significantly to nonattainment or interfere with maintenance
of the NAAQS, the State has a SIP-approved major source new source
review (NSR) program. South Carolina's SIP-approved nonattainment NSR
regulation is Regulation 61-62.5, Standard No. 7.1--Nonattainment New
Source Review, which applies to the construction of any new major
stationary source or major modification at an existing major stationary
source in an area designated as nonattainment. The State's SIP-approved
prevention of significant deterioration (PSD) regulation, Regulation
61-62.5, Standard No. 7--Prevention of Significant Deterioration,
applies to the construction of any new major stationary source or major
modification at an existing major stationary source in an area
designated as attainment or unclassifiable or not yet designated.
Regulation 61-62.1, Section II--Permit Requirements governs, among
other things, the preconstruction permitting of modifications and
construction of minor stationary sources in South Carolina. These major
(i.e., PSD and

nonattainment NSR (NNSR)) and minor NSR rules ensure that
SO2 emissions due to major modifications at existing major
stationary sources, modifications at minor stationary sources, and the
construction of new major and minor sources in South Carolina will not
contribute significantly to nonattainment of the 2010 1-hour
SO2 NAAQS in neighboring states.
5. Federally Enforceable Regulations Addressing SO2
Emissions in South Carolina
a. State Submission
    SC DHEC listed the following EPA rules which reduce SO2
emissions from various sources: Acid Rain Nitrogen Oxides Emission
Reduction Program; PSD/NNSR; Cap and Trade Programs for SO2
under 40 CFR part 96; Regional Haze; Heavy-Duty Engine and Vehicle
Standards and Highway Diesel Fuel Sulfur Control Requirements; Mercury
and Air Toxics Standards; and the Cross-State Air Pollution Rule. The
State notes that the overall effect of these rules has been a 56
percent reduction in SO2 emissions nationally from 2010 to
2016.
b. EPA Analysis
    EPA believes that the federal control measures for SO2
which South Carolina lists in the State's June 2018 submission
effectively address emissions of SO2 from sources in the
State and help ensure that SO2 emissions from South Carolina
do not contribute significantly to nonattainment of the 2010 1-hour
SO2 NAAQS in another state.
6. Conclusion
    EPA proposes to determine that South Carolina's June 25, 2018, SIP
submission satisfies the requirements of prong 1 of CAA section
110(a)(2)(D)(i)(I). This proposed determination is based on the
following considerations: DVs for South Carolina's AQS SO2
monitors within 50 km of another state's border have remained well
below the 2010 1-hour SO2 NAAQS from 2015-2017; DVs for
Georgia's and North Carolina's regulatory monitors within 50 km of
South Carolina's border have 2017 DVs below the 2010 1-hour
SO2 NAAQS; modeling for the one South Carolina DRR source
within 50 km of another state's border estimates impacts below the 2010
1-hour SO2 NAAQS; modeling for DRR sources in the
surrounding states of Georgia and North Carolina within 50 km of South
Carolina indicates that the areas around these sources do not violate
the 2010 1-hour SO2 NAAQS; downward SO2 emissions
trends in South Carolina may suggest that the State's sources are not
likely contributing to other states' ability to attain or maintain the
2010 1-hour SO2 NAAQS; SO2 emissions from South
Carolina sources not subject to the DRR which emitted over 100 tons of
SO2 in 2017 are not likely interacting with SO2
emissions from the nearest source in a bordering state in such a way as
to contribute significantly to nonattainment in North Carolina; annual
99th percentile 1-hour SO2 concentrations at the Buncombe
County DRR monitor in North Carolina are well below the 2010 1-hour
SO2 NAAQS; and current South Carolina statutes and SIP-
approved measures and federal emissions control programs adequately
control SO2 emissions from sources within South Carolina.
    Based on the analysis provided by South Carolina in its SIP
submission and EPA's analysis of the factors described in section
III.C, EPA proposes to find that sources within South Carolina will not
contribute significantly to nonattainment of the 2010 1-hour
SO2 NAAQS in any other state.

D. EPA's Prong 2 Evaluation--Interference With Maintenance of the NAAQS

    Prong 2 of the good neighbor provision requires state plans to
prohibit emissions that will interfere with maintenance of a NAAQS in
another state.
1. State Submission
    In its June 25, 2018, SIP submission, SC DHEC states that South
Carolina's SIP contains adequate provisions to prevent sources and
emissions activities within South Carolina from interfering with
maintenance of the 2010 1-hour SO2 NAAQS in any other state
based on the downward trend in SO2 emissions in the State
and the Southeast and on federal and state control measures. As
discussed in section III.A, SC DHEC included statewide SO2
emissions trends in its SIP submittal which show that SO2
emissions have declined since approximately 2005 and are continuing to
decline. SC DHEC included a figure showing SO2 emissions
trends in the Southeast from 2000 to 2016 and indicated that there is a
consistent downward trend in SO2 emissions over this time
period. The State noted that these SO2 emissions reductions
are primarily due to federal regulations requiring pollution control
devices and the decreased use of coal for electricity. In addition, as
discussed in sections III.C.4 and III.C.5, SC DHEC has statutes and
SIP-approved measures which address sources of SO2 emissions
in South Carolina and there are also federal measures that control
SO2 emissions in the State.
2. EPA Analysis
    In North Carolina v. EPA, the D.C. Circuit explained that the
regulating authority must give prong 2 ``independent significance''
from prong 1 by evaluating the impact of upwind state emissions on
downwind areas that, while currently in attainment, are at risk of
future nonattainment. North Carolina v. EPA, 531 F.3d at 910-911 (D.C.
Cir. 2008). For the prong 2 analysis, EPA evaluated the emissions
trends provided by South Carolina for the State and the Southeast,
evaluated air quality data, and assessed how future sources of
SO2 are addressed through existing SIP-approved and
federally enforceable regulations. Given the continuing trend of
decreasing SO2 emissions from sources within South Carolina
and the fact that all areas in other states within 50 km of the South
Carolina border have DVs attaining the 2010 1-hour SO2
NAAQS, EPA believes that evaluating whether these decreases in
emissions can be maintained over time is a reasonable criterion to
ensure that sources within South Carolina do not interfere with its
neighboring states' ability to maintain the 2010 1-hour SO2
NAAQS.
    Regarding SO2 air quality trends in the southeastern
United States, EPA notes that this region of the country has
experienced an 82 percent decrease in the annual 99th percentile of
daily maximum 1-hour averages between 2000 and 2017 based on 24
monitoring sites, and the most recently available data for 2017
indicates that the mean value at these sites was approximately 14
ppb.\34\ When this trend is evaluated alongside the monitored
SO2 concentrations within South Carolina as well as the
SO2 concentrations recorded at regulatory monitors in the
surrounding states of Georgia and North Carolina shown in Tables 6 and
7 of this document, EPA believes that emissions trends in South
Carolina due to sources from within the State are not significantly
different than the overall decreasing monitored SO2
concentration trend in the Southeast. With respect to air quality data
trends, the current 2015-2017 DVs for AQS SO2 monitors both
in South Carolina within 50 km of another state's border and in Georgia
and North Carolina within 50 km of South Carolina's border are below
the 2010 1-hour SO2 NAAQS. Further, modeling results for DRR
sources within 50 km of South Carolina's border both

within the State and in the states of Georgia and North Carolina
demonstrate attainment of the 2010 1-hour SO2 NAAQS, and
thus, demonstrate that South Carolina's largest point sources of
SO2 are not expected to interfere with maintenance of the
2010 1-hour SO2 NAAQS in another state.
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    \34\ See https://www.epa.gov/air-trends/sulfur-dioxide-trends.
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    As discussed in sections III.C.4 and III.C.5, EPA believes that
federal and State regulations and statutes that both directly and
indirectly reduce emissions of SO2 in South Carolina help
ensure that the State does not interfere with maintenance of the NAAQS
in another state. SO2 emissions from future major
modifications and new major sources will be addressed by South
Carolina's SIP-approved major NSR regulations described in section
III.C.4. In addition, South Carolina has a SIP-approved minor NSR
permit program addressing small emission sources of SO2. The
permitting regulations contained within these programs are designed to
ensure that emissions from these activities do not interfere with
maintenance of the NAAQS in the State or in any other state.
3. Conclusion
    EPA proposes to determine that South Carolina's June 25, 2018, SIP
submission satisfies the requirements of prong 2 of CAA section
110(a)(2)(D)(i)(I). This determination is based on the following
considerations: SO2 emissions statewide from 2008 to 2014 in
South Carolina have declined significantly; current South Carolina
statutes and SIP-approved measures and federal emissions control
programs adequately control SO2 emissions from sources
within South Carolina; South Carolina's SIP-approved PSD and minor
source NSR permit programs will address future large and small
SO2 sources; current DVs for AQS SO2 monitors
both in South Carolina within 50 km of another state's border and in
Georgia and North Carolina within 50 km of South Carolina's border are
below the 2010 1-hour SO2 NAAQS; and modeling for DRR
sources within 50 km of South Carolina's border both within the State
and in Georgia and North Carolina demonstrates that South Carolina's
largest point sources of SO2 are not expected to interfere
with maintenance of the 2010 1-hour SO2 NAAQS in another
state. Based on the analysis provided by South Carolina in its SIP
submission and EPA's supplemental analysis of the factors described in
section III.C and III.D of this document, EPA proposes to find that
emission sources within South Carolina will not interfere with
maintenance of the 2010 1-hour SO2 NAAQS in any other state.

IV. Proposed Action

    In light of the above analysis, EPA is proposing to approve South
Carolina's June 25, 2018, SIP submission as demonstrating that South
Carolina's SIP has adequate provisions prohibiting any source or other
type of emissions activity in the State from emitting any air pollutant
in amounts that will contribute significantly to nonattainment or
interfere with maintenance of the 2010 1-hour SO2 NAAQS in
another state.

V. 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. This action merely
proposes to approve 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);
     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
     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 South Carolina does not have
Tribal implications as specified by Executive Order 13175 (65 FR 67249,
November 9, 2000) because it does not have substantial direct effects
on an Indian Tribe. The Catawba Indian Nation Reservation is located
within the boundary of York County, South Carolina. Pursuant to the
Catawba Indian Claims Settlement Act, S.C. Code Ann. 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 this proposed rule does not have substantial direct
effects on an Indian Tribe because this proposed action is not
approving any specific rule, but rather proposing to determine that
South Carolina's already approved SIP meets certain CAA requirements.
EPA notes that these proposed actions 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, Particulate Matter, Reporting
and recordkeeping requirements, Sulfur oxides.

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

    Dated: April 11, 2019.
Mary S. Walker,
Acting Regional Administrator, Region 4.
[FR Doc. 2019-07921 Filed 4-22-19; 8:45 am]
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