Air Plan Approval; SC; 2010 1-Hour SO2, 16799-16809 [2019-07921]
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Federal Register / Vol. 84, No. 78 / Tuesday, April 23, 2019 / Proposed Rules
Appearance of Fabrics After Repeated
Home Laundering. AATCC 124–2006
requires the use of an automatic washer
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that meet certain conditions. Staff is
aware of the limited availability of
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alternatives, when possible.
3. Test Result Codes
The standard lists reporting codes in
16 CFR 1610.8(b)(2) to describe the
burning behavior of raised surface
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based on test results, indicate the proper
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clarification of these codes.
4. Additional Burdens Associated With
16 CFR Part 1610
Please provide other input and
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please identify test procedures that may
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Alberta E. Mills,
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Commission.
published in the Federal Register on
March 26, 2019. The proposed
regulations updated existing regulations
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DATES: Written or electronic comments
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FOR FURTHER INFORMATION CONTACT:
Concerning the proposed regulations,
Grid R. Glyer, (202) 317–6847;
concerning submission of comments,
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toll-free numbers).
SUPPLEMENTARY INFORMATION:
Background
The proposed regulations that are the
subject of this correction are under
sections 301, 356, 368, and 902 of the
Internal Revenue Code.
Need for Correction
BILLING CODE 6355–01–P
40 CFR Part 52
FOR FURTHER INFORMATION CONTACT:
Accordingly, the notice of proposed
rulemaking (REG–121694–16) that was
the subject of FR Doc. 2019–05649,
published at 84 FR 11263 (March 26,
2019), is corrected to read as follows:
§ 1.301–1
[Corrected]
On page 11266, first column, the sixth
and seventh lines of paragraph (f)(3)(ii),
the language ‘‘similar to, the transaction
in Notice 99–59’’ is corrected to read
‘‘similar to the transaction in, Notice
99–59’’.
■
BILLING CODE 4830–01–P
Internal Revenue Service
26 CFR Part 1
[REG–121694–16]
RIN 1545–BN80
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Updating Section 301 Regulations To
Reflect Statutory Changes; Correction
Internal Revenue Service (IRS),
Treasury.
ACTION: Correction to a notice of
proposed rulemaking.
AGENCY:
This document contains a
correction to a notice of proposed
rulemaking (REG–121694–16) that was
SUMMARY:
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Written comments must be
received on or before May 23, 2019.
DATES:
ENVIRONMENTAL PROTECTION
AGENCY
Correction of Publication
[FR Doc. 2019–08113 Filed 4–22–19; 8:45 am]
DEPARTMENT OF THE TREASURY
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.
Submit your comments,
identified by Docket ID No. EPA–R04–
OAR–2018–0665 at https://
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
https://www2.epa.gov/dockets/
commenting-epa-dockets.
As published, the notice of proposed
regulations (REG–121694–16) contains
errors which may prove to be
misleading and need to be clarified.
Martin V. Franks,
Chief, Publications and Regulations Branch,
Legal Processing Division, Associate Chief
Counsel (Procedure and Administration).
[FR Doc. 2019–08140 Filed 4–22–19; 8:45 am]
16799
[EPA–R04–OAR–2018–0665; FRL–9992–52–
Region 4]
Air Plan Approval; SC; 2010 1-Hour
SO2 NAAQS Transport Infrastructure
Environmental Protection
Agency (EPA).
ACTION: Proposed rule.
AGENCY:
The Environmental Protection
Agency (EPA) is proposing to approve
SUMMARY:
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ADDRESSES:
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
notarianni.michele@epa.gov.
SUPPLEMENTARY INFORMATION:
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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
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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
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
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.
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).
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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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 1hour 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
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
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.’’
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
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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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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
designations at https://www.epa.gov/sulfur-dioxidedesignations.
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-dioxidedesignations.
8 See Technical Support Document: Chapter 37
Final Round 3 Area Designations for the 2010 1Hour 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_rd3final.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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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.
As discussed in sections III.C and
III.D, EPA first reviewed the State’s
analysis to assess how the State
10 For the definition of spatial scales for SO ,
2
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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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
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 1hour 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
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.
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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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.
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.
TABLE 1—SUMMARY OF 2014 NEI (VERSION 2) SO2 DATA FOR SOUTH CAROLINA BY SOURCE CATEGORY
Emissions
(tpy)
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Category
Percent of
total SO2
emissions
Point ..........................................................................................................................................................................................................
Nonpoint ....................................................................................................................................................................................................
Fire ............................................................................................................................................................................................................
Onroad ......................................................................................................................................................................................................
Nonroad .....................................................................................................................................................................................................
46,913.26
2,986.99
2,300.06
546.07
47.85
89
6
4
1
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
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
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
14 EPA’s NEI is available at https://www.epa.gov/
air-emissions-inventories/national-emissionsinventory.
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.
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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are located within the ‘‘urban scale,’’
i.e., within 50 km of one or more state
borders.
TABLE 2—SUMMARY OF 2014 NEI
(VERSION 2) SO2 DATA FOR SOUTH
CAROLINA BY SOURCE TYPES
Emissions
(tpy)
Category
Fuel Combustion: EGUs (All Fuel
Types) ..........................................
Fuel Combustion: Industrial Boilers/
Internal Combustion Engines (All
Fuel Types) ..................................
Fuel Combustion: Commercial/Institutional (All Fuel Types) ..............
Fuel Combustion: Residential (All
Fuel Types) ..................................
Industrial Processes (All Categories) ........................................
Mobile Sources (All Categories) .....
Fires (All Types) ..............................
Waste Disposal ...............................
Solvent Processes ..........................
Miscellaneous (Non-Industrial) ........
SO2 Emissions Total ................
PO 00000
Frm 00007
Fmt 4702
Sfmt 4702
27,799.38
10,243.87
41.40
128.74
8,963.50
2,602.33
2,363.13
648.48
0.12
3.30
52,794.23
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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 3year 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.
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 50km 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.
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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
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).
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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.
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
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.
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
PO 00000
Frm 00008
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16803
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.
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
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.
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.
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in such a way as to contribute
significantly to nonattainment in that
state.
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 1hour 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 (DukeMarshall)).24 The predicted maximum
impacts from the model did not violate
the 2010 1-hour SO2 NAAQS for any of
the five sources.25
TABLE 3—SOUTH CAROLINA SOURCES WITH DRR MODELING LOCATED WITHIN 50 km OF ANOTHER STATE
DRR source
County
Approximate
distance from
source to
adjacent state
Resolute .............
York ..................
7 km .................
Other facilities included in
modeling
2010 1-hour
SO2 Model DV
(ppb)
Yes—Duke-Allen (NC); Winthrop
University; General Chemicals,
LLC;
Guardian
Industries;
Spring Industries—Leroy Plant.
69 *
Model grid extends into
another state?
Yes—into NC (western portion of
Union County in North Carolina)
* 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
County (state)
Approximate
distance from
source to
South Carolina
border
Plant McIntosh
(Modeled
with Savannah River
Mill).
Effingham
(GA).
Less than 5
km.
Savannah
River Mill
(Modeled
with Plant
McIntosh).
IP—Savannah
Effingham
(GA).
Less than 5
km.
Chatham (GA)
Duke-Allen .....
Duke-Marshall
DRR source
Other facilities included in
modeling
2010 1-hour SO2 model DV
(ppb)
Model grid extends into
another state?
Effingham County Power
(GA); SCE&G-Jasper Generating Station (SC)—
(based on allowable/potential to emit (PTE) emissions).
Effingham County Power
(GA); SCE&G-Jasper Generating Station (SC)—.
71.6 for both Plant McIntosh
and Savannah River Mill
(based on 2012–2014 actual emissions for Plant
McIntosh).
Yes—into SC (western portion of Jasper County, SC).
71.6 for both Plant McIntosh
and Savannah River Mill *.
Yes—into SC (western portion of Jasper County, SC).
Less than 5
km.
None ......................................
Yes—into SC (western portion of Jasper County, SC).
Gaston (NC) ..
5 km ..............
Duke-Marshall .......................
66 (based on 2011–2013 actual and allowable/PTE
emissions).
46.6 (based on 2013–2015
actual SO2 emissions).
Catawba (NC)
53 km ............
Duke-Allen .............................
68 (based on 2013–2015 actual SO2 emissions).
Yes—into SC (York County
and portions of Cherokee,
Union, Chester, Lancaster,
and Chesterfield Counties
in SC).
Yes—into SC (small portion
of York and Cherokee
Counties in SC).
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* 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.)
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:
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https://www.epa.gov/sites/production/files/201708/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.
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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.
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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
16805
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.
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
TABLE 5—SOUTH CAROLINA NON-DRR SO2 SOURCES EMITTING GREATER THAN 100 tpy NEAR NEIGHBORING STATES
South Carolina source
2017 Annual
SO2 emissions
(tons)
697
5.5
North Carolina ...........
23
103
1,480
22.5
44
North Carolina ...........
North Carolina ...........
53
68
Milliken & Co. Magnolia Plant.
Guardian Industries ...
WestRock CP LLC ....
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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.
The modeling results in Tables 3 and
4 predict no violations of the 2010 1hour 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
26 One source, Westrock CP, LLC accepted a
permit limit to exempt out of being subject to the
DRR.
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/
VerDate Sep<11>2014
Approximate
distance to
nearest
neighboring
state SO2
source
(km)
Approximate
distance to
South Carolina
border
(km)
17:17 Apr 22, 2019
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Closest neighboring
state
conclusion that sources in South
Carolina do not significantly contribute
to nonattainment of the 2010 1-hour SO2
NAAQS in any other state.
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.
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
production/files/2017-08/documents/38sc_so2_rd3final.pdf.
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).
Frm 00010
Fmt 4702
Sfmt 4702
Duke Energy Carolinas, LLC—Cliffside
Steam Station (858 tons).
Duke—Allen (354 tons).
Pilkington North America, Inc. (Pilkington)
(383 tons).
federally enforceable conditions
established in title V permits.
3. SO2 Ambient Air Quality
a. State Submission
2. SO2 Emissions Trends
PO 00000
Nearest neighboring state SO2 source &
2017 emissions
(>100 tons of SO2)
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.
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
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.
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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 1hour SO2 concentrations above the 2010
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.
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.
b. EPA Analysis
Since the time of development of
South Carolina’s SIP submission,
TABLE 6—2010 1-HOUR SO2 DVS FOR AQS MONITORS IN SOUTH CAROLINA WITHIN 50 km OF ANOTHER STATE’S
BORDER
AQS site
code
County
Greenville ..............
Oconee ..................
2010–2012
DV
(ppb)
450450008
450730001
2011–2013
DV
(ppb)
* ND
* ND
2012–2014
DV
(ppb)
* ND
* ND
2013–2015
DV
(ppb)
* ND
* ND
2014–2016
DV
(ppb)
3
3
2015–2017
DV
(ppb)
2
2
2
2
Approximate
distance to state
border
(km)
37 (NC)
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
AQS site
code
State
County
Georgia ................................
Chatham ..............................
Chatham ..............................
Richmond ............................
Mecklenberg ........................
North Carolina .....................
2010–
2012 DV
(ppb)
2011–
2013 DV
(ppb)
2012–
2014 DV
(ppb)
2013–
2015 DV
(ppb)
2014–
2016 DV
(ppb)
2015–
2017 DV
(ppb)
Approximate
distance to SC
border
(km)
68
74
* ND
14
79
66
* ND
10
78
* ND
* ND
7
70
* ND
61
7
52
* ND
60
5
48
32
52
5
3
2
6
20
130511002
130510021
132450091
371190041
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* 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
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.
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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 1hour concentration is not directly
comparable to the 2010 1-hour SO2
NAAQS, which is in the form of the 3year average of the 99th percentile of
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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 1hour 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
16807
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
County (state)
Round 4 monitored source
Buncombe (NC) ................................
Brunswick (NC) .................................
Haywood (NC) ..................................
Duke-Asheville .................................
CPI ...................................................
Evergreen .........................................
4. SIP-Approved Regulations and State
Statutes Addressing SO2 Emissions
jbell on DSK3GLQ082PROD with PROPOSALS
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 SIPapproved 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
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AQS site code
370210037
370190005
370870013
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
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
33 These South Carolina statutes are not approved
into the State’s implementation plan.
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2017 99th
percentile
concentration
(ppb)
16.6
82.5
206.8
2018 99th
percentile
concentration
(ppb)
9.8
55.1
213.4
Approximate
distance to SC
border
(km)
32
50
48
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
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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.
jbell on DSK3GLQ082PROD with PROPOSALS
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 1hour SO2 NAAQS; downward SO2
emissions trends in South Carolina may
suggest that the State’s sources are not
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likely contributing to other states’
ability to attain or maintain the 2010 1hour 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 SIPapproved 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
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Fmt 4702
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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 SIPapproved 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
34 See https://www.epa.gov/air-trends/sulfurdioxide-trends.
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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.
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.
jbell on DSK3GLQ082PROD with PROPOSALS
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
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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);
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Fmt 4702
Sfmt 9990
16809
• 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]
BILLING CODE 6560–50–P
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]]>Agencies
[Federal Register Volume 84, Number 78 (Tuesday, April 23, 2019)]
[Proposed Rules]
[Pages 16799-16809]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[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.
-----------------------------------------------------------------------
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 https://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 https://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:
[[Page 16800]]
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\
---------------------------------------------------------------------------
\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).
---------------------------------------------------------------------------
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\
---------------------------------------------------------------------------
\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\
[[Page 16801]]
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.
---------------------------------------------------------------------------
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).
---------------------------------------------------------------------------
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.
---------------------------------------------------------------------------
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
[[Page 16802]]
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.
---------------------------------------------------------------------------
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.
---------------------------------------------------------------------------
\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
[[Page 16803]]
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.
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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
[[Page 16804]]
in such a way as to contribute significantly to nonattainment in that
state.
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\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\
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\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.)
[[Page 16805]]
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.
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\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
[[Page 16806]]
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
[[Page 16807]]
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\
---------------------------------------------------------------------------
\33\ These South Carolina statutes are not approved into the
State's implementation plan.
---------------------------------------------------------------------------
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
[[Page 16808]]
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
[[Page 16809]]
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.
---------------------------------------------------------------------------
\34\ See https://www.epa.gov/air-trends/sulfur-dioxide-trends.
---------------------------------------------------------------------------
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]
BILLING CODE 6560-50-P
