Air Plan Approval; AL, FL, GA, KY, MS, NC, SC, TN; Interstate Transport for the 2012 PM2.5, 39387-39397 [2018-16991]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 83, Number 154 (Thursday, August 9, 2018)]
[Proposed Rules]
[Pages 39387-39397]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-16991]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R04-OAR-2016-0334; FRL-9982-00--Region 4]


Air Plan Approval; AL, FL, GA, KY, MS, NC, SC, TN; Interstate 
Transport for the 2012 PM2.5 NAAQS

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve portions of State Implementation Plan (SIP) submissions from 
Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South 
Carolina, and Tennessee addressing the Clean Air Act (CAA or Act) 
interstate transport infrastructure SIP requirements for the 2012 Fine 
Particulate Matter (PM2.5) National Ambient Air Quality 
Standards (NAAQS). The CAA requires that each state adopt and submit a 
SIP for the implementation, maintenance, and enforcement of each NAAQS 
promulgated by EPA, commonly referred to as an ``infrastructure SIP.'' 
EPA is proposing to approve the interstate transport portions of these 
infrastructure SIPs for the aforementioned states as demonstrating that 
air emissions in the states do not significantly contribute to 
nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state.

DATES: Comments must be received on or before August 30, 2018.

ADDRESSES: Submit your comments, identified by Docket ID No EPA-R04-
OAR-2016-0334 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: Richard Wong of the Air Regulatory 
Management Section, Air Planning and Implementation Branch, Air, 
Pesticides and Toxics Management Division, U.S. Environmental 
Protection Agency, Region 4, 61 Forsyth Street SW, Atlanta, Georgia 
30303-8960. Mr. Wong can be reached by telephone at (404) 562-8726 or 
via electronic mail at [email protected].

SUPPLEMENTARY INFORMATION:

I. Background

    On December 14, 2012, EPA revised the primary annual 
PM2.5 NAAQS to 12.0 micrograms per cubic meter ([mu]g/m\3\). 
See 78 FR 3086 (January 15, 2013). An area meets the standard if the 
three-year average of its annual average PM2.5 concentration 
(at each monitoring site in the area) is less than or equal to 12.0 
[mu]g/m\3\. States were required to submit infrastructure SIP 
submissions for the 2012 PM2.5 NAAQS to EPA no later than 
December 14, 2015.

[[Page 39388]]

    CAA section 110(a)(1) requires states to submit SIP revisions 
within three years after promulgation of a new or revised NAAQS in 
order to provide for the implementation, maintenance, and enforcement 
of the new or revised NAAQS. CAA section 110(a)(2) outlines the 
applicable requirements of such SIP submissions, which EPA has 
historically referred to as ``infrastructure SIP'' submissions. Section 
110(a)(2) requires states to address basic SIP elements such as 
monitoring, basic program requirements (e.g., permitting), and legal 
authority that are designed to assure attainment and maintenance of the 
newly established or revised NAAQS. Thus, section 110(a)(1) provides 
the procedural and timing requirements for infrastructure SIPs, and 
section 110(a)(2) lists specific elements that states must meet for the 
infrastructure SIP requirements related to a newly established or 
revised NAAQS. The contents of an infrastructure SIP submission may 
vary depending upon the data and analytical tools available to the 
state, as well as the provisions already contained in the state's 
implementation plan at the time in which the state develops and submits 
the submission for a new or revised NAAQS.
    Section 110(a)(2)(D) has two subsections: 110(a)(2)(D)(i) and 
110(a)(2)(D)(ii). Section 110(a)(2)(D)(i) includes four distinct 
components, commonly referred to as ``prongs,'' that must be addressed 
in infrastructure SIP submissions. The first two prongs, which are 
codified in section 110(a)(2)(D)(i)(I), require plans to prohibit any 
source or other type of emissions activity in one state from 
contributing significantly to nonattainment of the NAAQS in another 
state (prong 1) and from interfering with maintenance of the NAAQS in 
another state (prong 2). The third and fourth prongs, which are 
codified in section 110(a)(2)(D)(i)(II), are provisions that prohibit 
emissions activity in one state from interfering with measures required 
to prevent significant deterioration of air quality in another state 
(prong 3) or from interfering with measures to protect visibility in 
another state (prong 4). Section 110(a)(2)(D)(ii) requires SIPs to 
include provisions insuring compliance with sections 115 and 126 of the 
Act, relating to interstate and international pollution abatement.\1\
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    \1\ EPA highlighted the statutory requirement to submit 
infrastructure SIPs within three years of promulgation of a new 
NAAQS in an October 2, 2007, guidance document entitled ``Guidance 
on SIP Elements Required Under Sections 110(a)(1) and (2) for the 
1997 8-hour Ozone and PM2.5 National Ambient Air Quality 
Standards'' (2007 guidance). EPA has issued additional guidance 
documents and memoranda, including a September 13, 2013, guidance 
document titled ``Guidance on Infrastructure State Implementation 
Plan (SIP) Elements under Clean Air Act Sections 110(a)(1) and 
110(a)(2)'' (2013 guidance).
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    Through this notice, EPA is proposing to approve the prong 1 and 
prong 2 portions of infrastructure SIP submissions transmitted under 
cover letter by: Alabama (dated December 9, 2015); Florida (dated 
December 14, 2015); Georgia (dated December 14, 2015); Kentucky (dated 
February 8, 2016); Mississippi (dated December 8, 2015); North Carolina 
(dated December 4, 2015); South Carolina (dated December 14, 2015); and 
Tennessee (dated December 16, 2015), as demonstrating that these states 
do not significantly contribute to nonattainment or interfere with 
maintenance of the 2012 PM2.5 NAAQS in any other state.\2\ 
All other applicable infrastructure SIP requirements for these SIP 
submissions have been or will be addressed in separate rulemakings. A 
brief background regarding the 2012 PM2.5 NAAQS is provided 
below. For comprehensive information on the 2012 PM2.5 
NAAQS, please refer to the Federal Register notice cited above.
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    \2\ EPA notes that the Agency may not have received the 
submissions until after the date of the cover letter.
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II. What approach is EPA using to evaluate these SIP submissions?

    In several federal rulemakings, EPA has developed and consistently 
applied a framework for addressing prongs 1 and 2 of the interstate 
transport requirements with respect to the PM2.5 NAAQS. That 
framework has four basic steps, including: (1) Identifying downwind 
receptors that are expected to have problems attaining or maintaining 
the NAAQS; (2) identifying which upwind states contribute to these 
identified problems in amounts sufficient to warrant further review and 
analysis; (3) for states identified as contributing to downwind air 
quality problems, identifying upwind emissions reductions necessary to 
prevent an upwind state from significantly contributing to 
nonattainment or interfering with maintenance of the NAAQS downwind; 
and (4) for states that are found to have emissions that significantly 
contribute to nonattainment or interfere with maintenance of the NAAQS 
downwind, reducing the identified upwind emissions through adoption of 
permanent and enforceable measures. This framework was most recently 
applied with respect to PM2.5 in the Cross-State Air 
Pollution Rule (CSAPR), designed to address the 1997 and 2006 
PM2.5 standards as well as the 1997 ozone standards.
    EPA provided additional information in a memorandum published on 
March 17, 2016, titled ``Information on the Interstate Transport `Good 
Neighbor' Provision of the 2012 Fine Particulate Matter National 
Ambient Air Quality Standards under Clean Air Act Section 
110(a)(2)(D)(i)(I)'' (2016 memorandum).\3\ The 2016 memorandum provides 
information relevant to EPA Regional Office review of the CAA section 
110(a)(2)(D)(i)(I) ``good neighbor'' provision in infrastructure SIPs 
with respect to the 2012 PM2.5 NAAQS, describes EPA's past 
approach to addressing interstate transport, and provides EPA's general 
review of relevant modeling data and air quality projections as they 
relate to the 2012 PM2.5 NAAQS. This proposed rulemaking 
considers information provided in that memorandum.
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    \3\ This memorandum is available in the docket for this 
rulemaking and at https://www.epa.gov/sites/production/files/2016-05/documents/good-neighbor-memo_implementation.pdf.
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    In particular, the 2016 memorandum provides states and EPA Regional 
offices with information that is central to the first step in the 4-
step framework for determining whether an upwind area contributes 
significantly to downwind air quality problems, which is the 
identification of the downwind receptors that may present nonattainment 
or maintenance problems at the appropriate time. Specifically, the 2016 
memorandum provides projected future year annual PM2.5 
design values for monitors in the United States based on quality 
assured and certified ambient monitoring data and air quality modeling. 
The memorandum further describes how these projected potential design 
values can be used to help determine which monitors should be further 
evaluated to potentially address whether emissions from other states 
significantly contribute to nonattainment or interfere with maintenance 
of the 2012 PM2.5 NAAQS at those sites. The 2016 memorandum 
explains that for the purposes of addressing intestate transport for 
the 2012 PM2.5 NAAQS, it may be appropriate to evaluate 
projected air quality in 2021, which is the attainment deadline for 
2012 PM2.5 NAAQS nonattainment areas classified as moderate.
    In CSAPR, EPA defined nonattainment receptors as those monitoring 
sites that are projected to exceed the NAAQS in the appropriate future 
analytic year, while maintenance

[[Page 39389]]

receptors are monitoring sites that are projected to have difficulty 
maintaining the relevant NAAQS in a scenario that considers historical 
variability in air quality at that receptor (81 FR 74504, 74531, 
October 26, 2016). Accordingly, EPA used the average projected design 
value to identify potential ``nonattainment'' receptors, and the 
maximum projected design value to identify potential ``maintenance'' 
receptors. Since modeling results are only available for 2017 and 2025, 
one way to assess potential receptors for 2021 is to assume that 
receptors projected to have average and/or maximum design values above 
the NAAQS in both 2017 and 2025 are also likely to be either 
nonattainment or maintenance receptors in 2021. Similarly, it may be 
reasonable to assume that receptors that are projected to attain the 
NAAQS in both 2017 and 2025 are also likely to be attainment receptors 
in 2021. Where a potential receptor is projected to be nonattainment or 
maintenance in 2017, but projected to be attainment in 2025, further 
analysis of the emissions and modeling may be needed to make a further 
judgement regarding the receptor status in 2021.
    Based on this approach, according to the 2016 memorandum, all the 
potential nonattainment receptors and most of the maintenance receptors 
are in California, located in the San Joaquin Valley or South Coast 
nonattainment areas. However, there is also one potential maintenance 
receptor in Shoshone County, Idaho, and one potential maintenance 
receptor in Allegheny County, Pennsylvania. All other monitors in the 
United States that had at least one complete (and valid) 
PM2.5 design value for the annual average 2012 NAAQS in the 
2009-2013 period are projected to attain and maintain the 2012 
PM2.5 NAAQS in 2017 and 2025.
    The 2016 memorandum also notes that because of data quality 
problems, nonattainment and maintenance projections were not conducted 
for monitors in all or portions of Florida, Illinois, Idaho (outside of 
Shoshone County), Tennessee and Kentucky. EPA notes, however, that data 
quality problems have subsequently been resolved for all of the 
aforementioned areas. These areas have current design values \4\ below 
the 2012 PM2.5 NAAQS and are expected to continue to 
maintain the NAAQS due to downward emission trends for nitrogen oxides 
(NOX) and sulfur dioxide (SO2) and therefore are 
not considered potential receptors for the purpose of interstate 
transport for the 2012 PM2.5 NAAQS.
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    \4\ Current design values include the 2015-2017 available and 
certified data that states submitted to EPA on May 1, 2018, through 
the Air Quality System.
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    Therefore, from ``Step 1'' of this evaluation, the areas identified 
as ``potential downwind nonattainment and maintenance receptors'' are:
     Seventeen potential receptors in California, located in 
the San Joaquin Valley or South Coast nonattainment areas;
     Shoshone County, Idaho; and
     Allegheny County, Pennsylvania.
    As stated above, ``Step 2'' is the identification of states 
contributing to downwind nonattainment and maintenance receptors, such 
that further analysis is required to identify necessary upwind 
reductions. For this step, EPA will be specifically determining if 
emissions from the eight southeastern states contribute to the 
potential downwind nonattainment and maintenance receptors identified 
in Step 1.
    For the 1997 and 2006 PM2.5 NAAQS, EPA used air quality 
modeling and an air quality threshold of one percent of the 
PM2.5 NAAQS to identify upwind states that contribute to, 
and are thus ``linked'' to, projected nonattainment or maintenance 
receptors (76 FR 48237, August 8, 2011).\5\ If an upwind state impacts 
a downwind receptor by less than the one percent threshold, EPA 
determined that the state is not ``linked'' and therefore does not 
contribute to nonattainment at the receptor. Likewise, if there is no 
linkage to a maintenance receptor (based, again, on an impact of less 
than the one percent threshold), EPA determined the upwind state does 
not contribute to maintenance concerns at that receptor. EPA has not 
set an air quality threshold for the 2012 PM2.5 NAAQS, and 
does not have air quality modeling showing impacts on projected 
nonattainment or maintenance receptors for this NAAQS.
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    \5\ The 2012 contribution modeling is documented in EPA's ``Air 
Quality Modeling Final Rule Technical Support Document'' (June 2011) 
located in the docket for this proposed rulemaking and at https://www.epa.gov/csapr/cross-state-air-pollution-final-and-proposed-rules 
titled Contributions of 8-hour ozone, annual PM2.5, and 24-hour 
PM2.5 from each state to each monitoring site (Excel). EPA used the 
CAMx version 5.3 to simulate ozone and PM2.5 
concentrations for the 2005 base year and the 2012 and 2014 future 
year scenarios. CAMx was also used for the 2012 source apportionment 
modeling to quantify interstate transport of ozone and 
PM2.5.
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    In the absence of contribution modeling, EPA believes that a proper 
and well-supported weight of evidence approach can provide sufficient 
information for purposes of evaluating the impact of the southeastern 
states on potential downwind receptors with respect to the 2012 
PM2.5 NAAQS. As part of this weight of evidence approach, 
EPA considered the CSAPR air quality modeling conducted for purposes of 
evaluating upwind state impacts on downwind air quality with respect to 
the 1997 annual PM2.5 NAAQS of 15.0 [micro]g/m\3\ (as well 
as the 2006 24-hour PM2.5 NAAQS and 1997 Ozone NAAQS). 
Although not conducted for purposes of evaluating the 2012 
PM2.5 NAAQS, as noted above, this modeling can inform EPA's 
analysis regarding both the general magnitude of downwind 
PM2.5 impacts and the downwind distance in which states may 
contribute to receptors with respect to the 2012 annual 
PM2.5 NAAQS of 12.0 [micro]g/m\3\. In particular, if the 
same one percent contribution threshold used in CSAPR for the 1997 and 
2006 PM2.5 NAAQS applied to the 2012 PM2.5 NAAQS, 
EPA could consider the fact that a particular state's impact was below 
that value (that is, 0.12 [micro]g/m\3\). EPA notes the Agency has not 
set an air quality threshold for the 2012 p.m.2.5 NAAQS and the Agency 
does not have air quality modeling showing impacts on projected 
nonattainment or maintenance receptors for the 2012 p.m.2.5 NAAQS. In 
addition, EPA considers geographical information (primarily the 
distance between the southeastern states and the downwind receptors), 
including whether the receptors are upwind or downwind, and other 
information (e.g., emission trends, air quality data, regulation of 
PM2.5 and precursors) provided in the states' submittals. 
EPA notes that no single piece of information, by itself, is fully 
conclusive. Instead, the total weight of all the evidence taken 
together is used to evaluate significant contributions to nonattainment 
or interference with maintenance of the 2012 PM2.5 NAAQS in 
another state.
    EPA addresses Step 1 of the framework in section III, below, by 
discussing each of the potential downwind nonattainment and maintenance 
receptors. EPA mentions the California and Idaho receptors only briefly 
because they have little relevance for the eight southeastern states, 
as explained below. In section IV, below, EPA addresses Step 2 of the 
framework by discussing the southeastern states' impacts on the 
potential receptors. This proposed rulemaking considers the analyses 
from Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, 
South Carolina, and Tennessee as well as additional supplemental 
analysis

[[Page 39390]]

conducted by EPA during review of these submittals.\6\
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    \6\ Because EPA proposes to find that Alabama, Florida, Georgia, 
Kentucky, Mississippi, North Carolina, South Carolina, and 
Tennessee, individually, does not have emissions that contribute to 
any nonattainment or maintenance receptor in any other state, it is 
not necessary to evaluate steps 3 and 4 of the analytical framework 
described above.
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III. Potential Receptors

    As noted above, in Step 1 of the framework, EPA identifies the 
potential downwind nonattainment and maintenance receptors.

A. California

    California has seventeen potential receptors, located in the San 
Joaquin Valley or South Coast nonattainment areas. However, the nearest 
southeastern state is well over 1,000 miles--and downwind--from 
California. With this large distance and a general prevailing west to 
east wind flow, there is no evidence that any southeastern state will 
impact the California potential receptors, and as a result, EPA 
concludes that sources in Alabama, Florida, Georgia, Kentucky, 
Mississippi, North Carolina, South Carolina, and Tennessee do not 
significantly contribute to nonattainment or interfere with 
maintenance.

B. Shoshone County, Idaho

    Shoshone County, Idaho, has a potential maintenance receptor, but 
as with California, this receptor is well over 1,000 miles, and upwind 
from, the nearest southeastern state. With this distance and prevailing 
wind direction, there is no evidence that any southeastern state will 
impact this area, and as a result, EPA concludes that sources in 
Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South 
Carolina, and Tennessee do not significantly contribute to 
nonattainment or interfere with maintenance.

C. Allegheny County, Pennsylvania

    In the eastern United States, the modeling results provided in the 
2016 memorandum show that the Liberty monitor (AQS: 42-003-0064), 
located in Allegheny County, Pennsylvania (hereinafter referred to as 
the Liberty monitor or Allegheny County monitor), was projected to be 
above the 2012 PM2.5 NAAQS in the 2017 modeling (as a 
maintenance receptor). This monitor is, consistent with the projection, 
currently violating the 2012 PM2.5 NAAQS based on available 
and certified 2015-2017 ambient data measuring 13.0 [micro]g/m\3\. 
However, the monitor is projected to both attain and maintain the NAAQS 
in 2025. The 2016 memorandum indicates that under such a condition 
(where EPA's photochemical modeling indicates an area will attain and 
maintain the 2012 PM2.5 NAAQS in 2025 but not in 2017) 
further analysis of the site should be performed to determine if the 
site may be a nonattainment or maintenance receptor in 2021. A simple 
linear interpolation between the 2017 and 2025 projected design values 
for the Allegheny County monitor leads to a projected 2021 design value 
of 11.42 [mu]g/m\3\ and a maximum design value of 11.91 [mu]g/m\3\, 
which are both below the 2012 PM2.5 NAAQS, indicating the 
monitor is likely to attain the standard by the attainment deadline of 
2021.\7\
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    \7\ As noted in the 2016 memorandum, additional information 
about emissions and trends may be needed to further support this 
conclusion. Provided in the docket to this proposed rulemaking are 
the infrastructure SIP submissions which include information related 
to air quality data and trends in all states that are the subject of 
this proposed rulemaking (Docket ID: EPA-R04-OAR-2016-0334).
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    In addition to the modeling information, emissions and air quality 
data trends can help corroborate the interpolated 2021 values. Over the 
last decade, local and regional emissions reductions of primary 
PM2.5, SO2, and NOX, have led to large 
reductions in annual PM2.5 design values in Allegheny 
County, Pennsylvania. The 2015-2017 annual average PM2.5 
design value for the Liberty monitor is 13.0 [micro]g/m\3\, which is 
above the standard. Even so, expected emissions reductions in the next 
four years will lead to additional reductions in measured 
PM2.5 concentrations at the Liberty monitor.
    There are both local and regional components to the measured 
PM2.5 levels in Allegheny County and the greater Pittsburgh 
area. Previous CSAPR modeling showed that regional precursor emissions 
from upwind states contribute to PM2.5 nonattainment at the 
Liberty monitor. In recent years, large SO2 and 
NOX reductions from power plants have occurred in 
Pennsylvania and states upwind from the greater Pittsburgh region. 
Projected power plant closures and additional emission controls in 
upwind states will help further reduce both direct PM2.5 and 
PM2.5 precursors. Regional emissions reductions will 
continue to occur from current on-the-books federal and state 
regulations such as the federal on-road and non-road vehicle programs 
and various rules for major stationary emission sources. Additionally, 
local reductions to both direct PM2.5 and SO2 
emissions are expected and should also contribute to a further decline 
in Allegheny County's monitored PM2.5 concentrations. The 
Allegheny SO2 SIP also projects lower SO2 
emissions resulting from vehicle fuel standards, reductions in general 
emissions due to declining population in the Greater Pittsburgh region, 
and several shutdowns of significant sources of emissions in Allegheny 
County.
    In addition, in a supplemental analysis for this proposed 
rulemaking, EPA conducted a long-term trend analysis of the 
PM2.5 ambient air quality data using the Mann-Kendall trend 
test to detect increasing or decreasing trends at PM2.5 
monitoring sites in Pennsylvania (Allegheny, Delaware and Lebanon 
counties), Ohio (Cuyahoga and Lorain Counties) \8\ and southeastern 
Region 4 states as an additional weight of evidence. EPA found downward 
trends in all of those counties during the 2008-2017 time period. This 
trends analysis is discussed in the Technical Support Document (TSD) 
entitled Annual Fine Particulate Matter (PM2.5) Trend 
Analysis found in the docket for this proposed action (Docket ID: EPA-
R04-OAR-2016-0334). Not only have emissions trended downward in 
Allegheny County because of reductions from CSAPR implementation across 
the CSAPR states, emissions have trended downward nearly universally 
among PM air quality monitors in CSAPR states.\9\ This trend is 
reinforced by the air quality data presented in the 2016 memorandum.
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    \8\ EPA's 2016 memorandum does not identify the Cleveland, Ohio 
Area (Cuyahoga and Lorain counties), Lebanon and Delaware counties 
in Pennsylvania as a projected nonattainment or maintenance area in 
2017 or 2025; therefore, these areas were not considered potential 
receptors for purposes of interstate transport the 2012 
PM2.5 standard. Furthermore, monitors in the Cuyahoga 
(Harvard Yard monitor AQS ID: 39-035-0065) and Lorain (AQS ID: 39-
093-3002) are measuring below the annual standard at 11.7 [micro]g/
m\3\ and 7.6 [micro]g/m\3\ respectively, based on 2015-2017 data. 
Similarly, monitors in Delaware and Lebanon counites are also 
measuring below the 2012 PM2.5 standard based on 2015-
2017 design values.
    \9\ As described in the TSD, EPA found the same trend during 
2008-2017 in Cuyahoga and Lancaster Counties in Ohio, which are near 
Allegheny County in Pennsylvania.
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    Thus, EPA's modeling projections, the recent downward trends in 
local and upwind states' emissions, the expected downward trend in 
emissions between 2017 and 2021 and the downward trend in upwind 
monitored PM2.5 sites all indicate that the Liberty monitor 
will attain and be able to maintain the 2012 PM2.5 NAAQS by 
2021. Accordingly, EPA proposes to determine that Allegheny County is 
unlikely to have either nonattainment or maintenance problems in 2021 
and therefore should not be considered a receptor for

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purposes of interstate transport for the 2012 PM2.5 NAAQS.

IV. EPA's Review of How the Southeast States Addressed Prongs 1 and 2

    The following discussion summarizes EPA's individual analyses for 
the portions of submissions from Alabama, Florida, Georgia, Kentucky, 
Mississippi, North Carolina, South Carolina, and Tennessee intended to 
meet the prong 1 and prong 2 requirements of 110(a)(2)(D)(i)(I) for the 
2012 PM2.5 NAAQS. EPA's analysis is based on the 
supplemented CSAPR framework evaluation and information included in the 
states' submissions as a collective weight of evidence demonstration. 
The analysis focuses on evaluating whether there will be any downwind 
maintenance or nonattainment receptors in 2021, as discussed above, and 
the extent, if any, to which emissions from each of the eight states 
may impact any such downwind receptor. EPA evaluated the contribution 
modeling conducted in support of CSAPR (CSAPR contribution modeling) to 
determine if any of the eight southeastern states were projected to 
contribute greater than one percent of the annual standard (0.12 
[micro]g/m\3\) at certain downwind receptors with potential 
nonattainment/maintenance issues.\10\ For Alabama, Florida, Georgia, 
Mississippi, North Carolina and South Carolina, there are no impacts at 
any potential downwind receptor by at least that amount, which EPA 
considers an important indication that none of those states will 
contribute to such a receptor. EPA also considered information provided 
in the individual 2012 PM2.5 infrastructure SIP submissions 
and other information.
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    \10\ The 2012 contribution modeling is documented in EPA's ``Air 
Quality Modeling Final Rule Technical Support Document'' (June 2011) 
located in the docket for this proposed rulemaking and at https://www.epa.gov/csapr/cross-state-air-pollution-final-and-proposed-rules 
titled Contributions of 8-hour ozone, annual PM2.5, and 24-hour 
PM2.5 from each state to each monitoring site (Excel). EPA used the 
CAMx version 5.3 to simulate ozone and PM2.5 
concentrations for the 2005 base year and the 2012 and 2014 future 
year scenarios. CAMx was also used for the 2012 source apportionment 
modeling to quantify interstate transport of ozone and 
PM2.5.
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A. Alabama

    Alabama concluded in its December 9, 2015, PM2.5 
infrastructure SIP submission that it does not contribute significantly 
to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state for the following reasons: 
(1) There are no designated PM2.5 nonattainment areas in 
Alabama or in surrounding states; (2) available monitoring data in 
Alabama and the surrounding states for 2012-2014 show design values 
below the standard; (3) emissions of the PM precursors NOX 
and SO2 from point sources in Alabama have decreased by 10 
and 46 percent, respectively, for the years 2009-2013; and (4) there 
are federal and SIP-approved state regulations in place to control 
PM2.5 precursors. Based on the rationale discussed below, 
EPA proposes to approve Alabama's SIP submission on grounds that it has 
adequate provisions to ensure that emissions from sources within the 
State will not significantly contribute to nonattainment or interfere 
with maintenance of the 2012 PM2.5 NAAQS in any other state.
    Alabama's submission examined available PM2.5 monitoring 
data from 2012-2014 in the State and surrounding states. According to 
this data, the highest design value during this period was 11.6 [mu]g/
m\3\ at the North Birmingham monitor (AQS: 01-073-0023) in Alabama. 
Available quality-assured, certified data for 2015-2017 in Alabama and 
in the neighboring states is also below the standard. The highest valid 
2015-2017 design value in Alabama was 11.0 [mu]g/m\3\ at the 
Arkadelphia near-road site (01-073-2059) in Jefferson County. The 
highest valid design values in the neighboring states for 2015-2017 was 
10.5 [mu]g/m\3\ at the near-road site near Georgia Institute of 
Technology Fulton County, Georgia (13-121-0056). EPA's 10-year trend 
analysis indicates Alabama monitors generally exhibited a decreasing 
trend in PM2.5 concentrations from 2008 to 2017. More 
information on air quality trends in Alabama are provided in the TSD 
included in the docket for this proposed rulemaking.
    The NOX and SO2 point source emissions data 
provided in Alabama's submittal show that these emissions have 
decreased in the State by 10 and 46 percent, respectively, for 2009-
2013. Furthermore, as noted in the submittal, several coal-fired 
electricity generating units (EGUs) in Alabama were scheduled for 
retirement in 2016, further reducing NOX and SO2 
emissions.\11\
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    \11\ EPA identified four EGUs in Alabama that have retired units 
in the state including Tennessee Valley Authority (TVA) Colbert 
Fossil Plant, Colbert County, AL (units 1-5 retired April 30, 2016); 
Alabama Power Plant Barry, Mobile County, AL (unit 3 retired on 
August 24, 2015), TVA Widows Creek Fossil Plant, Jackson County, AL 
(units 1-6 retired June 25, 2014; units 7 and 8 retired April 30, 
2016) and Alabama Power Plant Gorgas, Walker County, AL (retired 
units 6 and 7 on August 24, 2015). Source https://www.epa.gov/airmarkets/business-center.
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    In its submittal, Alabama identifies SIP-approved regulations at 
Alabama Administrative Code Chapter 335-3-8 that require controls and 
emission limits for certain NOX emitting sources in the 
State. These regulations include the SIP-approved portion of the 
NOX SIP call that requires certain NOX emitting 
sources to comply with a capped NOX emission budget. The 
State also identifies SIP-approved regulations at Alabama 
Administrative Code Chapter 335-3-5 that require controls and emission 
limits for certain SO2 emitting sources in the State. 
Alabama further notes that it has implemented several federal programs 
that, while not relied upon to address its ``good neighbor'' 
obligations for the 2012 PM2.5 NAAQS, have reduced 
PM2.5 precursor emissions within the State. Alabama also 
controls certain sources that contribute to PM2.5 
concentrations in ambient air through its SIP-approved permitting 
regulations at Alabama Administrative Code Chapter 335-3-14. These 
permitting requirements help ensure that no new or modified sources in 
the State subject to these permitting regulations will contribute 
significantly to nonattainment or interfere with maintenance of the 
2012 PM2.5 NAAQS.
    EPA evaluated whether there are maintenance or nonattainment 
receptors for 2021 to which Alabama's emissions are linked. As noted in 
section III.C above, EPA's 2016 memorandum identifies the Allegheny 
County Liberty monitor (AQS ID: 42-003-0064) as a potential maintenance 
receptor in 2017, but indicates that it is likely to attain and 
maintain the annual standard in 2021. EPA's review of the CSAPR 
contribution modeling indicates that Alabama will not contribute 
greater than one percent of the 2012 standard (or 0.12 [mu]g/m\3\) to 
the Liberty monitor in Allegheny County. This result is consistent with 
the fact that the monitor is approximately 600 miles northeast of the 
Alabama border.
    Based on the weight of the evidence presented above, EPA proposes 
to approve Alabama's SIP submission on grounds that it adequately 
addresses the State's 110(a)(2)(D)(i)(I) good neighbor obligation for 
the 2012 PM2.5 standard and that the State will not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2012 PM2.5 NAAQS in any other state.

B. Florida

    Florida concluded in its December 14, 2015, PM2.5 
infrastructure SIP submission that emissions from sources in Florida do 
not significantly contribute to nonattainment or interfere with 
maintenance of the 2012 PM2.5 NAAQS in any other state for 
the following reasons: (1) There are no designated PM2.5 
nonattainment areas in

[[Page 39392]]

Florida or in surrounding states; (2) PM2.5 concentrations 
in the Southeast are in compliance with the standard; (3) modeling 
conducted by EPA in support of CSAPR indicates that Florida's 
contribution to any designated 2012 PM2.5 nonattainment area 
is less than 0.1 percent of the standard; (4) emissions of 
NOX and SO2 in Florida have decreased over the 
past decade; and (5) Florida has SIP-approved permitting regulations in 
place addressing certain activities that contribute to PM2.5 
concentrations in ambient air. Based on the rationale discussed below, 
EPA proposes to approve Florida's SIP submission on grounds that it has 
adequate provisions to ensure that emissions from sources within the 
State will not significantly contribute to nonattainment or interfere 
with maintenance of the 2012 PM2.5 NAAQS in any other state.
    Florida's submittal considered EPA's CSAPR contribution modeling 
and concluded that Florida's contribution to the designated 
nonattainment areas for the 2012 PM2.5 NAAQS is less than 
0.013 [mu]g/m\3\ (approximately 0.1 percent of the standard). The 
State's submittal also notes that NOX and SO2 
emissions in Florida have decreased by 50 percent and 70 percent, 
respectively, over the past decade. Florida states that these 
reductions lower Florida's potential impact on PM2.5 
concentrations in other states.
    Florida also identified SIP-approved regulations in the Florida 
Administrative Code, including Chapters 62-210, 62-212, and 62-296, 
that provide for the implementation of a permitting program required 
under Title I, Parts C and D of the CAA for certain activities that 
contribute to ambient PM2.5 concentrations. These permitting 
requirements help ensure that no new or modified sources in the State 
subject to these permitting regulations will contribute significantly 
to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS. Chapter 62-296 also contains additional SIP-
approved regulations that control certain sources that contribute to 
PM2.5 concentrations in the ambient air.
    Furthermore, as Florida notes in its submittal, the nearest 
designated nonattainment area is over 1,000 kilometers (or 621.371 
miles) from its northern border, and most of the direct and precursor 
PM2.5 emissions in the State are located in central and 
south Florida. Available quality-assured, certified data for 2015-2017 
in Florida and in the neighboring states is also below the standard. 
The highest valid 2015-2017 design value in Florida was 8.0 [mu]g/m\3\ 
at the Sydney site (AQS ID: 12-057-3002) in Hillsborough County. The 
highest valid design value in the neighboring states was 11.0 [mu]g/
m\3\ at the Arkadelphia near-road site (AQS ID: 01-073-2059) in 
Jefferson County, Alabama. EPA's 10-year trend analysis indicates that 
Florida monitors generally exhibited a decreasing trend in 
PM2.5 concentrations from 2008 to 2017. More information on 
air quality trends in Florida are provided in the TSD included in the 
docket for this proposed rulemaking.
    EPA's supplemental analysis focused on whether there are 
maintenance or nonattainment receptors for 2021 to which Florida's 
emissions are linked. As noted in section III.C above, EPA's 2016 
memorandum identifies the Allegheny County Liberty monitor (AQS ID: 42-
003-0064) as a potential maintenance receptor in 2017, but indicates 
that it is likely to attain and maintain the annual standard in 2021. 
EPA's review of the CSAPR contribution modeling indicates that 
Florida's contribution to the Liberty monitor is less than one percent 
of the 2012 PM2.5 NAAQS which is consistent with Florida's 
determination that sources in the State will not contribute to greater 
than one percent of the standard. In addition, the Allegheny County 
Liberty monitoring site is approximately 700 miles from the Florida 
state border.
    Based on weight of the evidence presented above, EPA proposes to 
approve Florida's SIP submission on grounds that it addresses the 
State's 110(a)(2)(D)(i)(I) good neighbor obligation for the 2012 
PM2.5 standard and that the State will not significantly 
contribute to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state.

C. Georgia

    Georgia concluded in its December 14, 2015, PM2.5 
infrastructure SIP submission that it does not contribute significantly 
to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state for the following reasons: 
(1) Modeling conducted by EPA in support of CSAPR indicates that 
Georgia's contribution to any designated 2012 PM2.5 
nonattainment area is less than one percent of the standard; and (2) 
Georgia has SIP-approved permitting regulations that control certain 
sources that contribute to PM2.5 concentrations in ambient 
air. Furthermore, there are currently no designated nonattainment areas 
in Georgia or in the surrounding states. Based on the rationale 
discussed below, EPA proposes to approve Georgia's SIP submission on 
grounds that it has adequate provisions to ensure that emissions from 
sources within the State will not significantly contribute to 
nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state.
    Based on Georgia's review of the CSAPR contribution modeling, the 
State concluded that its maximum potential contribution to the 
designated nonattainment areas for the 2012 PM2.5 NAAQS is 
less than 0.081 [mu]g/m\3\ (less than 0.7 percent of the standard), and 
therefore, sources in the State do not contribute to downwind receptors 
with potential downwind nonattainment and/or maintenance issues. In 
addition, Georgia identifies SIP-approved permitting regulations in 
Georgia Rules for Air Quality 391-3-1-.02 and -.03 that implement the 
permitting programs required under Title I, Parts C and D of the CAA 
for certain activities that contribute to ambient PM2.5 
concentrations. These permitting requirements help ensure that no new 
or modified sources in the State subject to these permitting 
regulations will contribute significantly to nonattainment or interfere 
with maintenance of the 2012 PM2.5 NAAQS. Georgia also 
identified several SIP-approved Rules that require enforceable limits 
and control measures for PM2.5 and precursor emissions 
within the State as well as other federally-enforceable measures not 
part of the approved SIP that require reduction in SO2 
emission for certain sources in the State. Available quality-assured, 
certified data for 2015-2017 indicate that the highest design value in 
Georgia was 10.5 [mu]g/m\3\ at the near road site by Georgia Institute 
of Technology in Fulton County (AQS ID: 13-121-0056). The highest 
design value in the surrounding states was 11.0 [mu]g/m\3\ at the 
Arkadelphia near-road site in Jefferson County, Alabama (AQS ID: 01-
073-2059). EPA's 10-year trend analysis indicated that Georgia monitors 
generally exhibited a decreasing trend in PM2.5 
concentrations from 2008 to 2017. More information on air quality 
trends in Georgia are provided in the TSD included in the docket for 
this proposed rulemaking.
    EPA's supplemental analysis focused on whether there are 
maintenance or nonattainment receptors for 2021 to which Georgia's 
emissions are linked. As noted in section III.C above, EPA's 2016 
memorandum identifies the Allegheny County Liberty monitor (AQS ID: 42-
003-0064) as a potential maintenance receptor in 2017, but indicates 
that it is likely to attain and maintain the annual standard in 2021. 
Georgia's review of the CSAPR contribution modeling, as provided in

[[Page 39393]]

the State's 2015 SIP submittal, indicates that sources in the State 
will contribute less than one percent of the 2012 standard to the 
Liberty monitor which is consistent with EPA's review of the projected 
contribution modeling. In addition, the Allegheny Liberty monitor (AQS 
ID: 42-003-0064) is approximately 500 miles away from the Georgia state 
border.
    Based on the weight of the evidence presented above, EPA proposes 
to approve Georgia's SIP submission on grounds that it adequately 
addresses the State's 110(a)(2)(D)(i)(I) good neighbor obligation for 
the 2012 PM2.5 standard and that the State will not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2012 PM2.5 NAAQS in any other state.

D. Kentucky

    Kentucky concluded in its February 8, 2016, PM2.5 
infrastructure SIP submission that the Commonwealth will not contribute 
significantly to nonattainment or interfere with maintenance of the 
2012 PM2.5 NAAQS in any other state for the following 
reasons: (1) Available monitoring data in Kentucky and in the 
surrounding states for 2012-2014 (with the exception of the Cleveland, 
Ohio nonattainment area) have shown design values below the standard; 
(2) air quality monitors between Kentucky and the Cleveland Area (the 
only designated 2012 PM2.5 nonattainment area in a 
neighboring state) show attainment from 2012-2014; and (3) Kentucky has 
SIP-approved regulations to assure that the State is not interfering 
with attainment or maintenance of the 2012 PM2.5 NAAQS in 
any other state. Based on the rationale discussed below, EPA proposes 
to approve Kentucky's SIP submission on grounds that it has adequate 
provisions to ensure that emissions from sources within the 
Commonwealth will not significantly contribute to nonattainment or 
interfere with maintenance of the 2012 PM2.5 NAAQS in any 
other state.
    Kentucky's SIP submission indicates that the most significant 
sources of PM2.5 and its precursors are coal-fired power 
plants, industrial boilers, and other combustion sources.
    Kentucky's 2015 infrastructure SIP submission identifies several 
SIP-approved regulations that regulate sources of PM2.5 
precursor emissions (as well as other federally-enforceable measures 
not part of the federally-approved SIP); reductions in PM2.5 
precursor emissions in Kentucky due to permanent and enforceable 
emission reduction measures; and the downward trend of PM2.5 
monitored concentrations in Kentucky and surrounding states.\12\
---------------------------------------------------------------------------

    \12\ Kentucky also identifies the Cleveland Area (Cuyahoga and 
Lorain Counties) as the only PM2.5 nonattainment area in 
a neighboring state. This area is approximately 200 miles from the 
Kentucky border. The Cuyahoga County Harvard Yard monitor (AQS ID: 
39-035-0065) and Lorain monitor (AQS ID: 39-093-3002) in the 
Cleveland Area are both are measuring below the annual standard at 
11.7 [mu]g/m\3\ and 7.6 [mu]g/m\3\ respectively, based on 2015-2017 
air quality data. EPA's 2016 memorandum does not identify the 
Cleveland Area as a projected potential nonattainment or maintenance 
area in 2017 or 2025. Therefore, this area was not considered a 
downwind receptor for the 2012 PM2.5 standard.
---------------------------------------------------------------------------

    Kentucky identifies SIP-approved permitting regulations at 40 
Kentucky Administrative Rules (KAR) 51:017 and 51:052 used to control 
certain sources that contribute to PM2.5 concentrations in 
ambient air. These permitting requirements help ensure that no new or 
modified sources in the Commonwealth subject to these permitting 
regulations will significantly contribute to nonattainment or interfere 
with maintenance of the 2012 PM2.5 NAAQS. Kentucky also 
controls emissions of PM2.5 and PM2.5 precursors 
at certain sources through source-specific measures pursuant to other 
SIP-approved regulations such as 40 KAR 51:150 (NOX 
requirements for stationary internal combustion engines). Kentucky also 
identifies CSAPR as yielding residual NOX and SO2 
emission reductions.
    Kentucky examined available PM2.5 monitoring data from 
2012-2014 in the Commonwealth and in surrounding states. According to 
this data, the highest valid design values in Kentucky and surrounding 
states (excluding the Cleveland Area) was 11.8 [mu]g/m\3\ at the W. 
18th St. monitor in Marion County, Indiana. Available quality-assured, 
certified data for 2015-2017 in Kentucky and the surrounding states are 
also below the standard. The highest design value in Kentucky was 9.7 
[mu]g/m\3\ at the Southwick (AQS ID: 21-111-0043) site in Jefferson 
County. The highest valid design value in the neighboring states was 
11.7 [mu]g/m\3\ at the Harvard Yard monitor in Cuyahoga County, Ohio, 
within the Cleveland Area. Furthermore, the monitors between the 
Commonwealth and the Cleveland Area show attaining 2015-2017 design 
values. EPA's 10-year trend analysis indicates that Kentucky monitors 
generally exhibited a decreasing trend in PM2.5 
concentrations from 2008 to 2017. More information on air quality 
trends in Kentucky are provided in the TSD included in the docket for 
this proposed rulemaking.
    EPA's supplemental analysis focused on whether there are 
maintenance or nonattainment receptors for 2021 to which source 
emissions in Kentucky emissions are linked. As discussed in section 
III.C above, EPA's 2016 memorandum identifies the Allegheny County 
Liberty monitor (AQS ID: 42-003-0064) as a potential maintenance 
receptor in 2017, but indicates that the monitor is likely to attain 
and maintain by 2021. EPA's review of the CSAPR contribution modeling 
indicates that sources in the Commonwealth contribute 0.273 [mu]g/m\3\ 
to the Liberty monitoring site which is greater than one percent of the 
2012 standard. EPA notes that current SO2 emissions in 
Kentucky are 204,812 tons,\13\ lower than modeled SO2 
emissions of 520,546 tons for the CSAPR.\14\ Kentucky's highest 
contribution when considering all Allegheny monitors is at the Liberty 
monitor. The Allegheny County Liberty monitoring site is approximately 
400 miles upwind from the Kentucky border.
---------------------------------------------------------------------------

    \13\ The 2014 NEI v2 emissions are available in the docket for 
this rulemaking.
    \14\ The CSAPR modeled SO2 emissions numbers, for the 
2012 contribution case, can be found in this TSD in Table 7-4 at 
https://www.epa.gov/sites/production/files/2017-06/documents/epa-hq-oar-2009-0491-4522.pdf.
---------------------------------------------------------------------------

    As discussed in section III.C, above, local and regional emissions 
reductions of primary PM2.5, SO2, and 
NOX, have led to large reductions in annual PM2.5 
design values in Allegheny County, Pennsylvania. Based on EPA's 
modeling projections, the recent downward trend in local and regional 
emissions reductions, the expected continued downward trend in 
emissions between 2017 and 2021, and the downward trend in monitored 
PM2.5 concentrations, EPA expects that the Liberty monitor 
will attain and be able to maintain the 2012 PM2.5 NAAQS by 
the 2021 attainment deadline without additional PM2.5 
precursor emission reductions from Kentucky. As mentioned above, the 
2015-2017 annual average PM2.5 design value for the Liberty 
monitor is 13.0 [mu]g/m\3\, which is above the 2012 PM2.5 
standard. Even so, expected emissions reductions in the next four years 
will lead to additional reductions in measured PM2.5 
concentrations at the Liberty monitor. Therefore, EPA proposes to 
determine that additional emission reductions from sources in the 
Commonwealth are not necessary to satisfy the Commonwealth's 
obligations under section 110(a)(2)(D)(i)(I) of the CAA. For these 
reasons, EPA proposes to determine that Kentucky's emissions will not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2012 PM2.5 NAAQS for Allegheny County, Pennsylvania.

[[Page 39394]]

    Based on the weight of the evidence presented above, EPA proposes 
to approve Kentucky's SIP submission on grounds that it adequately 
addresses the Commonwealth's 110(a)(2)(D)(i)(I) good neighbor 
obligation for the 2012 PM2.5 standard and that the 
Commonwealth will not significantly contribute to nonattainment or 
interfere with maintenance of the 2012 PM2.5 NAAQS in any 
other state.

E. Mississippi

    Mississippi concluded in its December 8, 2015, PM2.5 
infrastructure SIP submission that it does not contribute significantly 
to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state for the following reasons: 
(1) There are no designated PM2.5 nonattainment areas in 
Mississippi or in surrounding states; (2) available monitoring data in 
Mississippi and in the surrounding states for 2011-2014 show annual 
average concentrations below the standard; and (3) there are SIP-
approved state regulations in place to control emissions of 
PM2.5 and PM2.5 precursors. Based on the 
rationale discussed below, EPA proposes to approve Mississippi's SIP 
submission on grounds that it has adequate provisions to ensure that 
emissions from sources within the State will not significantly 
contribute to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state.
    Mississippi's 2015 submittal identifies SIP-approved permitting 
regulations at Mississippi Administrative Code APC-S-2 used to control 
sources of precursor emissions that contribute to PM2.5 
concentrations in ambient air. These permitting requirements help 
ensure that no new or modified sources in the State subject to these 
permitting regulations will significantly contribute to nonattainment 
or interfere with maintenance of the 2012 PM2.5 NAAQS.
    Mississippi's SIP submittal also reviewed available 
PM2.5 monitoring data from 2009-2014 in the State and in 
surrounding states. The State concluded that design values during this 
period were generally trending downward and the highest design value 
for 2012-2014 was 11.3 [mu]g/m\3\ at a monitor in Alabama. EPA's review 
of available quality-assured, certified data for 2015-2017 determined 
that the highest design value in Mississippi was 8.9 [mu]g/m\3\ at the 
Hattiesburg, Mississippi site (AQS ID: 28-035-0004). In the neighboring 
states, the highest valid 2015-2017 design value was 11.0 [mu]g/m\3\ at 
the Arkadelphia near-road site in Jefferson County, Alabama (AQS ID: 
01-073-2059). EPA's 10-year trend analysis indicated that Mississippi 
monitors generally exhibited a decreasing trend in PM2.5 
concentrations from 2008 to 2017.\15\ More information on air quality 
trends in Mississippi are provided in the TSD included in the docket 
for this proposed rulemaking.
---------------------------------------------------------------------------

    \15\ Due to incomplete data as a result of quality assurance 
findings in a Technical Systems Audit conducted by the EPA, none of 
the PM2.5 monitoring sites in Mississippi collected 
enough data to produce a valid annual mean during 2012-2014. Despite 
this missing data, in EPA's assessment, the trends analysis still 
provides informative results for the Mississippi sites. Most of the 
sites did collect complete annual means during the most recent 
years, 2015, 2016, and 2017. Also, many of the sites collected five, 
six, or seven valid annual means during the 2008-2017 period, which 
met the minimum completeness criteria developed for the trends 
analysis.
---------------------------------------------------------------------------

    EPA's supplemental analysis focused on whether there are 
maintenance or nonattainment receptors for 2021 to which Mississippi's 
emissions are linked. As noted in section III.C above, EPA's 2016 
memorandum identifies the Allegheny County Liberty monitor (AQS ID: 42-
003-0064) as a potential maintenance receptor in 2017, but indicates 
that it is likely to attain and maintain the annual standard in 2021. 
EPA's review of the CSAPR contribution modeling indicates that 
Mississippi does not contribute greater than one percent of the 2012 
standard to that site. This is consistent with the fact that the 
monitor is approximately 600 miles northeast of the Mississippi state 
border.
    Based on the weight of the evidence presented above, EPA proposes 
to approve Mississippi's SIP submission on grounds that it adequately 
addresses the State's 110(a)(2)(D)(i)(I) good neighbor obligation for 
the 2012 PM2.5 standard and that the State will not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2012 PM2.5 NAAQS in any other state.

F. North Carolina

    North Carolina concluded in its December 4, 2015, PM2.5 
infrastructure SIP submission that it does not contribute significantly 
to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state for the following reasons: 
(1) There are no designated PM2.5 nonattainment areas in 
North Carolina or in surrounding states; (2) available monitoring data 
in North Carolina and in the surrounding states for 2011-2014 show 
design values below the standard; (3) PM2.5, NOX, 
and SO2 emissions in the State have declined since 1996; and 
(4) there are federal and SIP-approved state regulations in place to 
ensure that North Carolina is not interfering with attainment or 
maintenance of the standard in downwind states. Based on the rationale 
discussed below, EPA proposes to approve North Carolina's SIP 
submission on the grounds that it has adequate provisions to ensure 
that emissions from sources within the State will not significantly 
contribute to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state.
    The State's implementation plan submittal reviewed emissions data 
and projections from 1996-2017 and concluded that PM2.5, 
NOX, and SO2 emissions within North Carolina 
declined by approximately 36, 48, and 80 percent, respectively, from 
1996-2011 and are projected to decrease by an additional 31, 39, and 50 
percent, respectively, from 2011-2017 due to state and federal 
programs.\16\ The State estimates that emissions of these pollutants 
will continue to decrease beyond 2017.
---------------------------------------------------------------------------

    \16\ See Table 3--Trends in North Carolina's Annual Statewide 
Emissions (Thousand Tons/Year) in North Carolina's 2015 SIP 
submission. For 1990 through 2011, emissions are from the EPA's 
National Emissions Inventory located at https://www3.epa.gov/ttn/chief/eiinformation.html. For 2013, emissions were estimated by the 
State. For 2017, emissions are from the EPA's 2017 v6.2 modeling 
platform emissions summary, located at: ftp://ftp.epa.gov/EmisInventory/2011v6/v2platform/reports/2017eh_cb6v2_v6_11g_state_sector_totals.xlsx.
---------------------------------------------------------------------------

    North Carolina reviewed EPA's air quality modeling analyses 
conducted in support of the decision to revise the annual 
PM2.5 standard to 12.0 [mu]g/m\3\ where EPA concluded that 
all states downwind of North Carolina would attain the 2012 
PM2.5 NAAQS by 2020; one year prior to the 2021 attainment 
year for the three areas in Pennsylvania designated as moderate 
nonattainment areas (see Table 2 in North Carolina's December 4, 2015 
submittal). North Carolina does not believe that it has any significant 
contribution to annual PM2.5 concentrations in these areas 
in Pennsylvania because the entire state of North Carolina and the 
states between North Carolina and Pennsylvania (i.e., Virginia, West 
Virginia and Maryland) were attaining the annual standard at the time 
of the State's submittal in 2015.
    North Carolina's SIP submission also cites to a number of State 
regulations that address additional control measures, means, and 
techniques to reduce relevant emissions in North Carolina.\17\ Several 
of these measures,

[[Page 39395]]

means, and techniques are SIP-approved, such as 15A North Carolina 
Administrative Code (NCAC) 02D.1409 (addressing NOX 
emissions from certain stationary internal combustion engines) and the 
NOX and SO2 emissions caps under the State's 2002 
Clean Smokestack Act (CSA) \18\ that apply to certain coal-fired power 
plants in the State. North Carolina also identifies a number of federal 
programs such as CSAPR that, while not relied upon to address its 
``good neighbor'' obligations for the 2012 PM2.5 NAAQS, 
reduce emissions of PM2.5 and/or PM2.5 
precursors.\19\
---------------------------------------------------------------------------

    \17\ North Carolina identifies a number of SIP-approved state 
regulations that control emissions or PM2.5 precursors 
within the State as well as some State regulations that are not part 
of the federally-approved SIP.
    \18\ EPA approved the CSA emissions caps into North Carolina's 
SIP on September 26, 2011. See 76 FR 59250. The first cap was 
effective in 2007 and a significant step forward towards complying 
with 1997 PM2.5 and 8-hour ozone NAAQS.
    \19\ CSAPR currently caps EGUs in the State at specific 
NOX and SO2 emission budgets.
---------------------------------------------------------------------------

    In addition, North Carolina examined available PM2.5 
monitoring data from 2011-2014 in the State and surrounding states. 
According to this data, the highest valid design value for 2012-2014 
was 10.9 [mu]g/m\3\ at the Macon Allied monitor in Bibb County, Georgia 
(AQS ID: 13-021-0007). The highest valid 2015-2017 design values in 
North Carolina is 8.8 [mu]g/m\3\ at two sites (Durham Armory site in 
Durham County; AQS ID: 37-063-0015, Millbrook School site in Wake 
County; AQS ID: 37-183-0014). The highest valid design value in the 
neighboring states was 10.5 [mu]g/m\3\ at the near road site by Georgia 
Institute of Technology in Fulton County, Georgia (AQS ID: 13-121-
0056). Also, EPA's 10-year trend analysis indicates that North Carolina 
monitors generally exhibited a decreasing trend in PM2.5 
concentrations from 2008 to 2017. More information on air quality 
trends in North Carolina are provided in the TSD included in the docket 
for this proposed rulemaking.
    EPA's supplemental analysis focused on whether there are 
maintenance or nonattainment receptors for 2021 to which source 
emissions in North Carolina emissions are linked. As noted in section 
III.C above, EPA's 2016 memorandum identifies the Allegheny County 
Liberty monitor (AQS ID: 42-003-0064) as a potential maintenance 
receptor in 2017, but indicates that it is likely to attain and 
maintain the annual standard in 2021. EPA's review of the CSAPR 
contribution modeling indicates that North Carolina does not contribute 
greater than one percent of the 2012 standard.
    Based on the weight of the evidence presented above, EPA proposes 
to approve North Carolina's SIP submission on grounds that it 
adequately addresses the State's 110(a)(2)(D)(i)(I) good neighbor 
obligation for the 2012 PM2.5 standard and that the State 
will not significantly contribute to nonattainment or interfere with 
maintenance of the 2012 PM2.5 NAAQS in any other state.

G. South Carolina

    South Carolina concluded in its December 14, 2015, PM2.5 
infrastructure SIP submission that it does not contribute significantly 
to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state for the following reasons: 
(1) There are no designated PM2.5 nonattainment areas in 
South Carolina or in surrounding states; (2) available monitoring data 
in South Carolina for 2010-2014 show design values below the standard 
and PM2.5 concentrations have declined over the majority of 
the Southeast since 2006; (3) estimated PM2.5 emissions from 
title V sources in the State have declined overall from 2003-2014; \20\ 
and (4) there are SIP-approved state regulations in place to control 
PM2.5 and PM2.5 precursor emissions. Based on the 
rationale discussed below, EPA proposes to approve South Carolina's SIP 
submission on grounds that it has adequate provisions to ensure that 
emissions from sources within the State will not significantly 
contribute to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state.
---------------------------------------------------------------------------

    \20\ Title V of the CAA requires major sources of air 
pollutants, and certain other sources, to obtain and operate in 
compliance with an operating permit.
---------------------------------------------------------------------------

    South Carolina's SIP submission identifies SIP-approved permitting 
regulations at South Carolina Code of Regulations 61-62.5, Standard No. 
7 and Standard No. 7.1 used to control certain sources that contribute 
to PM2.5 concentrations in ambient air. These permitting 
requirements help ensure that no new or modified sources in the State 
subject to these permitting regulations will significantly contribute 
to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS. South Carolina also controls emissions of 
PM2.5 and PM2.5 precursors at certain sources 
through source-specific measures pursuant to other SIP-approved 
regulations such as Regulation 61-62.2 (prohibitions on open burning), 
Regulation 61-62.5, Standard No. 1 (emissions from fuel burning 
operations), and Regulation 61-62.6 (control of fugitive particulate 
matter).
    In addition, South Carolina provided estimated PM2.5 
emissions data for title V sources in the State showing that these 
emissions have decreased by approximately 66 percent from 2003-2014, 
and the State reports that PM2.5 emissions continue to 
decrease in South Carolina. Furthermore, there are currently no 
designated nonattainment areas in South Carolina or in the surrounding 
states. South Carolina examined PM2.5 monitoring data from 
2005-August 2015 in the State and determined that the design values 
have been below the standard since 2010. The State also determined that 
PM2.5 design values over most of the Southeast have declined 
since 2006. Available certified design value for 2015-2017 in South 
Carolina and in the surrounding states is also below the standard. The 
highest valid 2015-2017 design value in South Carolina was 9.1 [mu]g/
m\3\ at the Greenville ESC site in Greenville County (AQS ID: 45-045-
0015). The highest valid design value in the neighboring states was 
10.5 [mu]g/m\3\ at the near road site by Georgia Institute of 
Technology in Fulton County, Georgia (AQS ID: 13-121-0056). EPA's 10-
year trend analysis indicates that South Carolina monitors generally 
exhibited a decreasing trend in PM2.5 concentrations from 
2008 to 2017. More information on air quality trends in South Carolina 
are provided in the TSD included in the docket for this proposed 
rulemaking.
    EPA's supplemental analysis focused on whether there are 
maintenance or nonattainment receptors for 2021 to which source 
emissions in South Carolina are linked. As noted in section III.C 
above, EPA's 2016 memorandum identifies the Allegheny County Liberty 
monitor (AQS ID: 42-003-0064) as a potential maintenance receptor in 
2017, but indicates that it is likely to attain and maintain the annual 
standard in 2021. EPA's review of the CSAPR contribution modeling 
indicates that North Carolina will not contribute greater than one 
percent of the 2012 standard to the Liberty monitor. This is consistent 
with the fact that the monitor is approximately 365 miles northeast of 
the South Carolina border.
    Based on the weight of the evidence presented above, EPA proposes 
to approve South Carolina's SIP submission on grounds that it 
adequately addresses the State's 110(a)(2)(D)(i)(I) good neighbor 
obligation for the 2012 PM2.5 standard and that the State 
will not significantly contribute to nonattainment or interfere with 
maintenance of the 2012 PM2.5 NAAQS in any other state.

[[Page 39396]]

H. Tennessee

    Tennessee concluded in its December 16, 2015 PM2.5 
infrastructure SIP submission that it does not contribute significantly 
to nonattainment or interfere with maintenance of the 2012 
PM2.5 NAAQS in any other state for the following reasons: 
(1) There are no designated PM2.5 nonattainment areas in 
Tennessee or in surrounding states; (2) available monitoring data in 
Tennessee show design values below the standard and PM2.5 
concentrations have declined over the majority of the Southeast since 
2006; (3) estimated PM2.5 precursor emissions from Tennessee 
EGUs have declined; and (4) there are SIP-approved state regulations in 
place to control PM2.5 and PM2.5 precursor 
emissions. Based on the rationale discussed below, EPA proposes to 
approve Tennessee's SIP submission on grounds that it has adequate 
provisions to ensure that emissions from sources within the State will 
not significantly contribute to nonattainment or interfere with 
maintenance of the 2012 PM2.5 NAAQS in any other state.
    Tennessee indicated that a number of SO2 control 
measures are being implemented at many of the State's largest sources. 
For example, the Tennessee Valley Authority (TVA) is subject to a 
Federal Facilities Compliance Agreement (FFCA) \21\ and a consent 
decree \22\ that require TVA to retire several coal-fired units and to 
take a number of other measures to reduce SO2 emissions. 
Tennessee estimated that the retirements alone will decrease emissions 
by roughly 27,268 tons of SO2 from 2014 levels, a 46 percent 
reduction. Additionally, the FFCA and the consent decree require 
certain TVA coal-fired units to install selective catalytic reduction 
system and flue gas desulfurization system controls and require units 
with these controls to operate the controls continuously.
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    \21\ Federal Facilities Compliance Agreement Between the United 
States Environmental Protection Agency and the Tennessee Valley 
Authority, In the Matter of: Tennessee Valley Authority, Docket No. 
CAA-04-2010-1760. The FFCA is available at https://www.epa.gov/sites/production/files/documents/tva-ffca.pdf.
    \22\ State of Alabama et. al. v. TVA, Civil Action No. 3:11-cv-
00170 (E.D. Tenn., approved June 30, 2011) imposes certain 
requirements on various TVA facilities that are enforceable in 
accordance with the terms of that agreement. The consent decree is 
available at https://www.epa.gov/sites/production/files/documents/tvacoal-fired-cd.pdf.
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    Additionally, Tennessee notes that all coal-fired EGUs in the State 
are subject to 40 CFR 63 Subpart UUUUU, Mercury and Air Toxics 
Standards, which require further unit level reductions to emissions of 
mercury, particulate matter, SO2, hydrogen chloride, and 
several other hazardous pollutants. Tennessee estimated that 
PM2.5 emissions data for title V sources in the state have 
decreased by approximately 66 percent from 2003-2014, and are expected 
to continue to decrease. Tennessee also identified several SIP-approved 
Tennessee Air Pollution Control Rules that require enforceable limits 
and control measures for PM2.5 and precursor emissions \23\ 
within the State as well as other federally-enforceable measures not 
part of the federal-approved SIP that require reduction in 
SO2 emissions for certain sources in the State. Currently 
available quality-assured, certified data for 2015-2017 in Tennessee 
and in the surrounding states is below the annual standard. The highest 
valid 2015-2017 design value in Tennessee was 10.0 [micro]g/m\3\ at the 
Air Lab site in Knox County (AQS ID: 47-093-1013). The highest valid 
design value in the neighboring states was 11.0 [micro]g/m\3\ at the 
Arkadelphia near-road site in Jefferson County, Alabama (AQS ID: 01-
073-2059). EPA's 10-year trend analysis indicate that Tennessee 
monitors generally exhibited a decreasing trend in PM2.5 
concentrations from 2008 to 2017. More information on air quality 
trends in Tennessee are provided in the TSD included in the docket for 
this proposed rulemaking.
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    \23\ See Table 1 in Tennessee's SIP submittal.
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    EPA's supplemental analysis focused on whether there are 
maintenance or nonattainment receptors for 2021 to which source 
emissions in Tennessee emissions are linked. As noted in section III.C 
above, EPA's 2016 memorandum identifies the Allegheny County Liberty 
monitor (AQS ID: 42-003-0064) as a potential maintenance receptor in 
2017, but indicates that it is likely to attain and maintain the annual 
standard in 2021. Tennessee's review of the CSAPR contribution 
modeling, as provided in the State's 2015 SIP submittal, indicates that 
sources in the State contribute 0.133 [mu]g/m\3\ to the Liberty 
monitoring site which is greater than one percent of the 2012 standard 
and consistent with EPA's review of the CSAPR contribution 
modeling.\24\ The Allegheny County monitor is approximately 300 miles 
upwind from the Tennessee border. EPA notes that current precursor 
SO2 emissions in Tennessee are 58,450 tons,\25\ lower than 
modeled SO2 emissions of 324,377 tons, for the CSAPR.\26\
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    \24\ See Table 4 in Tennessee's SIP submittal.
    \25\ The 2014 NEI v2 emissions are available in the docket for 
this rulemaking.
    \26\ The CSAPR modeled SO2 emissions numbers, for the 
2012 contribution case, can be found in this TSD in Table 7-4 at 
https://www.epa.gov/sites/production/files/2017-06/documents/epa-hq-oar-2009-0491-4522.pdf.
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    Tennessee's 2015 SIP submission identifies several SIP-approved 
regulations that regulate sources of PM2.5 precursor 
emissions (as well as other federally-enforceable measures not part of 
the federally-approved SIP), reductions in PM2.5 precursor 
emissions due to permanent and enforceable emission reduction measures, 
and the downward trend of PM2.5 monitored concentrations in 
Tennessee and surrounding states. Additionally, as discussed in section 
III.C above, both local and regional emissions reductions of primary 
PM2.5, SO2, and NOX, have led to large 
reductions in annual PM2.5 design values in Allegheny 
County, Pennsylvania. The Liberty monitor is already close to attaining 
the NAAQS. As mentioned above, the 2015-2017 annual average 
PM2.5 design value for the Liberty monitor is 13.0 [mu]g/
m\3\, which is above the 2012 PM2.5 standard. Even so, 
expected emissions reductions in the next four years will lead to 
additional reductions in measured PM2.5 concentrations at 
the Liberty monitor. Based on EPA's modeling projections, the recent 
downward trend in local and regional emissions reductions, the expected 
continued downward trend in emissions between 2017 and 2021, and the 
downward trend in monitored PM2.5 concentrations, EPA 
expects that the Liberty monitor will attain and be able to maintain 
the 2012 PM2.5 NAAQS by the 2021 attainment deadline without 
additional PM2.5 precursor emission reductions from 
Tennessee. Therefore, EPA proposes to determine that additional 
emission reductions from sources in Tennessee are not necessary to 
satisfy the State's obligations under section 110(a)(2)(D)(i)(I) of the 
CAA. For these reasons, EPA proposes to determine that Tennessee's 
emissions will not significantly contribute to nonattainment or 
interfere with maintenance of the 2012 PM2.5 NAAQS for 
Allegheny County, Pennsylvania.
    Based on the weight of the evidence presented above, EPA proposes 
to approve Tennessee's SIP submission on grounds that it adequately 
addresses the State's 110(a)(2)(D)(i)(I) good neighbor obligation for 
the 2012 PM2.5 standard and that the State will not 
significantly contribute to nonattainment or interfere with maintenance 
of the 2012 PM2.5 NAAQS in any other state.

IV. Proposed Action

    As described above, EPA is proposing to approve the portions of the 
aforementioned infrastructure

[[Page 39397]]

submissions from Alabama, Florida, Georgia, Kentucky, Mississippi, 
North Carolina, South Carolina, and Tennessee addressing prongs 1 and 2 
of CAA section 110(a)(2)(D)(i) for the 2012 PM2.5 NAAQS.

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, these proposed actions:
     Are not significant regulatory actions 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);
     Are not Executive Order 13771 (82 FR 9339, February 2, 
2017) regulatory actions because SIP approvals are exempted under 
Executive Order 12866;
     Do not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Are 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.);
     Do 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);
     Do not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Are not economically significant regulatory actions based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Are not significant regulatory actions subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Are 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 this rulemaking does not involve technical standards; and
     Do not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).
    The SIPs subject to these proposed actions, with the exception of 
the South Carolina SIP, are not approved to apply on any Indian 
reservation land or in any other area where EPA or an Indian tribe has 
demonstrated that a tribe has jurisdiction. In those areas of Indian 
country, the rule does not have tribal implications as specified by 
Executive Order 13175 (65 FR 67249, November 9, 2000), nor will it 
impose substantial direct costs on tribal governments or preempt tribal 
law. With respect to the South Carolina SIP, EPA notes that the Catawba 
Indian Nation Reservation is located within South Carolina, and 
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.'' 
Thus, the South Carolina SIP applies to the Catawba Reservation; 
however, because the proposed action related to South Carolina is not 
proposing to approve any specific rule into the South Carolina SIP, but 
rather proposing to find that the State's already approved SIP meets 
certain CAA requirements, EPA proposes to determine that there are no 
substantial direct effects on the Catawba Indian Nation. EPA has also 
preliminarily determined that the proposed action related to South 
Carolina's SIP will not impose any substantial direct costs on tribal 
governments or preempt tribal law.

List of Subjects in 40 CFR Part 52

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

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

    Dated: July 31, 2018.
Onis ``Trey'' Glenn, III,
Regional Administrator, Region 4.
[FR Doc. 2018-16991 Filed 8-8-18; 8:45 am]
BILLING CODE 6560-50-P