[Federal Register Volume 84, Number 153 (Thursday, August 8, 2019)]
[Proposed Rules]
[Pages 38895-38898]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-16936]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R06-OAR-2019-0438; FRL-9997-72-Region 6]


Air Plan Approval; Arkansas; Interstate Transport Requirements 
for the 2010 1-Hour SO2 NAAQS

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: Pursuant to the Federal Clean Air Act (CAA or the Act), the 
Environmental Protection Agency (EPA) is proposing to approve the 
portion of Arkansas' State Implementation Plan (SIP) submittal 
addressing the CAA requirements pertaining to the ``good neighbor'' 
provision of the CAA for the 2010 Sulfur Dioxide (SO2) 
National Ambient Air Quality Standard (NAAQS). The ``good neighbor'' 
provision requires each state's implementation plan contain adequate 
provisions prohibiting emissions which will contribute significantly to 
nonattainment or interfere with maintenance of the 2010 SO2 
NAAQS in other states. EPA is proposing to determine that consistent 
with the CAA, Arkansas' SIP contains adequate provisions to ensure that 
air emissions in Arkansas will not contribute significantly to 
nonattainment or interfere with maintenance of the 2010 SO2 
NAAQS in any other state.

DATES: Written comments must be received on or before September 9, 
2019.

ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2019-0438, at http://www.regulations.gov or via email to 
salem.nevine@epa.gov. Follow the online instructions for submitting 
comments. Once submitted, comments cannot be edited or removed from 
Regulations.gov. The 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

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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. The 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, please contact Ms. Nevine 
Salem, (214) 665-7222, salem.nevine@epa.gov. For the full EPA public 
comment policy, information about CBI or multimedia submissions, and 
general guidance on making effective comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.
    Docket: The index to the docket for this action is available 
electronically at www.regulations.gov and in hard copy at the EPA 
Region 6, 1201 Elm Street, Suite 500, Dallas, Texas. While all 
documents in the docket are listed in the index, some information may 
be publicly available only at the hard copy location (e.g., copyrighted 
material), and some may not be publicly available at either location 
(e.g., CBI).

FOR FURTHER INFORMATION CONTACT: Nevine Salem, EPA Region 6 Office, 
Infrastructure and Ozone Section, 1201 Elm Street, Suite 500, Dallas, 
TX 75270, (214) 665-7222, salem.nevine@epa.gov. To inspect the hard 
copy materials, please schedule an appointment with Ms. Salem or Mr. 
Bill Deese at (214) 665-7253.

SUPPLEMENTARY INFORMATION: Throughout this document ``we,'' ``us,'' and 
``our'' means the EPA.

I. Background

A. General

    On June 2, 2010, the EPA established a new primary 1-hour 
SO2 NAAQS of 75 parts per billion (ppb), based on a three-
year average of the annual 99th percentile of 1-hour daily maximum 
concentrations.\1\ The CAA requires states to submit, within three 
years after promulgation of a new or revised NAAQS, SIPs meeting the 
applicable ``infrastructure'' elements of sections 110(a)(1) and (2). 
One of these applicable infrastructure elements, CAA section 
110(a)(2)(D)(i), requires SIPs to contain ``good neighbor'' provisions 
to prohibit certain adverse air quality effects on neighboring states 
due to interstate transport of pollution.
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    \1\ 75 FR 35520 (June 22, 2010).
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B. EPA's Infrastructure SIP Requirements

    Whenever EPA promulgates a new or revised NAAQS, CAA section 
110(a)(1) requires states to make SIP submissions to provide for the 
implementation, maintenance, and enforcement of the NAAQS. This 
particular type of SIP submission is commonly referred to as an 
``infrastructure SIP.'' These submissions must meet the various 
requirements of CAA section 110(a)(2), as applicable.

C. Interstate Pollution Transport Requirements

    Section 110(a)(2)(D)(i)(I) of the CAA requires a state's SIP to 
include adequate provisions prohibiting any emissions activity in the 
state that will contribute significantly to nonattainment, or 
interferes with maintenance, of the NAAQS in any downwind state. The 
EPA sometimes refers to these requirements as prong 1 (contribute 
significantly to nonattainment) and prong 2 (interference with 
maintenance), or jointly as the ``good neighbor'' provision of the CAA. 
Further information can be found in the Technical Support Document 
(TSD) for this rulemaking action, which is available online at 
www.regulations.gov, Docket number EPA-R06-OAR-2019-0438.

II. Summary of Arkansas' SIP Submittal and EPA's Evaluation

A. Arkansas' SIP Submittal

    On March 24, 2017, the Arkansas Department of Environmental Quality 
(ADEQ) submitted an infrastructure SIP (i-SIP) addressing how the 
existing Arkansas SIP provides for the implementation, maintenance, and 
enforcement of the 2010 1-hour SO2 NAAQS.\2\ On February 14, 
2018 (83 FR 6470), the EPA approved most elements of Arkansas i-SIP 
submittal, but we took no action regarding the interstate transport 
provisions of section 110(a)(2)(D)(i)(I) pertaining to significant 
contribution to nonattainment (prong 1) and interference with 
maintenance (prong 2) of the NAAQS in other states.
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    \2\ This proposed approval action is based on the information 
contained in the administrative record for this action and does not 
prejudge any other future EPA action that may make other 
determinations regarding any of the subject state's air quality 
status. Any such future actions, 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 the 
EPA's SO2 Data Requirements Rule (80 FR 51052, August 21, 
2015) and information submitted to the EPA by states, air agencies, 
and third-party stakeholders such as citizen groups and industry 
representatives.
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    The portions of Arkansas' March 24, 2017 SIP submittal addressing 
interstate transport (for section 110(a)(2)(D)(i)(I)) discuss how 
Arkansas will not contribute significantly to nonattainment in, or 
interfere with maintenance by, any other state with respect to the 2010 
1-hour SO2 NAAQS. ADEQ evaluated SO2 monitoring 
data within Arkansas and its surrounding states (Oklahoma, Texas, 
Louisiana, Mississippi, Missouri and Tennessee), and concluded that its 
emissions will not contribute significantly to nonattainment or 
interfere with maintenance of the 2010 1-hour SO2 NAAQS in 
any other state. In its submittal Arkansas described several existing 
SIP-approved measures and other federally enforceable source-specific 
measures, including permitting requirements, that apply to 
SO2 sources within the state.

B. EPA's Evaluation

    For this CAA Section 110 (a)(2)(D)(i)(I) evaluation of the 2010 
SO2 NAAQS, EPA conducted a weight of evidence analysis for 
each prong separately,\3\ including available information such as air 
quality, emission sources, modeling and emission trends in Arkansas and 
the adjacent nearby states that border Arkansas.
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    \3\ In North Carolina v. EPA, 531 F.3d at 910-911 (D.C. Cir. 
2008), 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.
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1. EPA's Prong 1 Evaluation--Contribute Significantly to Nonattainment
    Prong 1 of the ``good neighbor'' provisions requires states' plans 
to prohibit emissions that will contribute significantly to 
nonattainment of the NAAQS in another state. ADEQ confirms in its 
submission that Arkansas' SIP contains adequate provisions to prevent 
sources and other types of emission activities within the State from 
contributing significantly to nonattainment in other states with 
respect to the 2010 1-hour SO2 standard. The EPA's 
evaluation \4\ of whether Arkansas has met its Prong 1 transport

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obligations was accomplished by considering these factors:
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    \4\ A detailed review of EPA's evaluation of emissions, air 
monitoring data, other technical information, and rationale for 
proposed approval of this SIP revision as meeting CAA section 
110(a)(2)(D)(i)(I) for the 2010 1-hour SO2 NAAQS may be 
found in the Technical Support Document (TSD) attached to this 
docket.
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    (1) SO2 ambient air quality and emissions trends for 
Arkansas and neighboring states;
    (2) Potential ambient impacts of SO2 emissions from 
certain facilities \5\ in Arkansas on neighboring states based on 
available air dispersion modeling results of SO2 sources in 
Arkansas and surrounding states and proximity analysis;
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    \5\ The physical properties of SO2 result in 
relatively localized pollutant impacts very near the emissions 
source. Therefore, the EPA selected a spatial scale with dimensions 
up to 50 km from point sources.
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    (3) Analysis of the relationship of Arkansas sources with monitors 
in adjacent states which have recorded elevated SO2 
concentrations;
    (4) Arkansas' SIP-approved regulations specific to SO2 
emissions and permit requirements; and,
    (5) Other SIP-approved or federally enforceable regulations which 
may reduce SO2 emissions either directly or indirectly.
    Based on EPA's analysis and evaluation of Arkansas' March 24, 2017 
SIP submittal addressing the requirements of prong 1 of CAA section 
110(a)(2)(D)(i)(I) requirement, we agree with Arkansas' conclusion that 
the existing Arkansas SIP is adequate to prevent sources in the state 
from contributing significantly to nonattainment in another state with 
respect to the 2010 1-hour SO2 NAAQS. EPA proposes to 
determine that Arkansas' March 24, 2017 SIP submittal satisfies the 
requirements of Prong 1 of CAA section 110(a)(2)(D)(i)(I). This 
proposed determination is based on the following considerations:
     There are no monitors recording violations of the 2010 
SO2 NAAQS located in Arkansas or within 50 km of its border. 
Additionally, all monitors within 50 km of the Arkansas border have 
design values (DV) \6\ that are well below the 75 ppb standard and are 
unlikely to violate the standard in the future, indicating no potential 
concern for Prong 1. Current DVs for Arkansas' AQS SO2 
monitors within 50 km of another state's border have remained well 
below the 2010 1-hour SO2 NAAQS from 2015-2017; similarly; 
SO2 monitors for neighboring states (Oklahoma, Texas, 
Louisiana, Missouri and Tennessee) within 50 km of Arkansas have 2017 
DVs below 2010 1-hour NAAQS standards;
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    \6\ The design value is the 3-year average of the 99th 
percentile 1-hour daily maximums at a monitor. A control strategy 
should be designed to bring the value to attainment of the standard.
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     Modeling for the two Arkansas' Data Requirements Rule 
(DRR) sources \7\ within 50 km of an adjacent state's border estimates 
impacts below the 2010 1-hour SO2 NAAQS, and modeling for 
the DRR sources in surrounding states within 50 km of Arkansas 
indicates that areas around these sources do not violate the 2010 
SO2 NAAQS;
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    \7\ On August 21, 2015 (80 FR 51052), EPA 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.
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     Significant downward SO2 emissions trends in 
Arkansas and its surrounding states (Texas, Oklahoma, Louisiana, 
Missouri, and Tennessee), when considered together with the other 
factors discussed as part of EPA's weight of evidence analysis, further 
decreases the probability that the State's sources are significantly 
contributing to other states' ability to attain the 2010 1-hour 
SO2 NAAQS;
     An analysis of Arkansas sources emitting over 100 tons of 
SO2 in 2017 show that these sources will not combine with 
emissions from the nearby sources in neighboring states to contribute 
significantly to nonattainment in those states. These analyses show the 
nearby sources have been modeled to show compliance of the 2010 
standard or the modeling of the nearby sources included the Arkansas 
sources as background concentration or the Arkansas sources were well 
beyond 50 km from the adjacent states making it unlikely that Arkansas 
sources will contribute significantly to nonattainment in those states; 
and
     EPA also evaluated the most recent monitoring data for DRR 
monitors located in states adjacent to Arkansas and within 50 km of the 
state's border.\8\ There are three monitors that fall into this 
category, one in Oklahoma and two in Missouri. The Oklahoma monitor's 
measurements meet the standard by a wide margin. So, Arkansas sources 
are not contributing to nonattainment or interfering with maintenance 
at that monitor. The monitors in Missouri recorded exceedances of the 
2010 SO2 NAAQS for 2018, the only complete year of data. The 
nearest Arkansas sources, however, are of relatively small size (less 
than 300 tpy) and beyond the chosen 50 km spatial scale. Furthermore, 
the location of the Arkansas sources relative to Missouri DRR sources 
and the Missouri monitors that are recording exceedances are such that 
transport from the Arkansas sources could not significantly contribute 
to the monitors (or areas around the monitors) at the same time as the 
DRR sources are having their maximum impact. Therefore, the Arkansas 
sources will not have a significant impact on the measured exceedances; 
and,
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    \8\ There are five DRR monitored sources within 50 km of 
Arkansas the border. Two DRR sources are in Arkansas (Flint Creek 
Power Plan, in Benton County, Arkansas and Plum Point Energy Station 
in Mississippi County, Arkansas). Three DRR sources are outside of 
Arkansas (GRDA Power Plant in Mayes, Oklahoma, Noranda Aluminum Inc 
and New Madrid Power Plant Marston both in New Madrid, Missouri).
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     Current Arkansas' statutes, SIP-approved and federal 
emissions control regulations will continue to adequately control 
SO2 emissions from sources within Arkansas.
    Based on the analysis provided by Arkansas in its SIP submittal, 
the summary of EPA's evaluation, and EPA's supplemental Prong 1 
analysis given in the TSD for this action, EPA proposes to find that 
sources within Arkansas will not significantly contribute to 
nonattainment of the 2010 1-hour SO2 NAAQS in any other 
state.
2. EPA's Prong 2 Evaluation--Interference With Maintenance
    Prong 2 of the ``good neighbor'' provision requires state plans to 
prohibit emissions that will interfere with maintenance of a NAAQS in 
another state. For the Prong 2 analysis, EPA evaluated the 
SO2 emissions trends for Arkansas, evaluated air quality 
data, and assessed how future sources of SO2 are addressed 
through existing SIP-approved and federally enforceable regulations. As 
discussed in more detail in the TSD, current available modeling for 
areas in other states within 50 km of the Arkansas border show 
attainment of the 2010 1-hour SO2 NAAQS supporting that 
sources within Arkansas will not interfere with neighboring states' 
ability to maintain the 2010 1-hour SO2 NAAQS. Emissions 
over time are not anticipated to increase relative to the baseline 
emissions modeled. EPA believes that federal and state regulations and 
statutes directly and indirectly reduced emissions of SO2 in 
Arkansas and help to 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 Arkansas' SIP-approved major NSR regulations

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described in more detail in the TSD. In addition, Arkansas 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 
will not interfere with maintenance of the SO2 NAAQS in 
Arkansas or any other state.
    EPA proposes to determine that Arkansas' March 24, 2017 SIP 
submittal satisfies the requirements of Prong 2 of CAA section 
110(a)(2)(D)(i)(I). This determination is based on the following 
considerations:
     Statewide SO2 emissions from 2000 to 2017 in 
Arkansas have declined significantly and are expected to continue to 
decline, tending to reduce background concentrations in neighboring 
states;
     Current Arkansas statutes and SIP-approved measures and 
federal emissions control programs adequately control SO2 
emissions from sources within Arkansas;
     Arkansas' SIP-approved PSD and minor source NSR permit 
programs will address future new and modified SO2 sources 
above major and minor permitting thresholds;
     Current 2015-2017 DVs for Air Quality System (AQS) \9\ 
SO2 monitors both in Arkansas within 50 km of another 
state's border and in neighboring states (Oklahoma, Texas, Louisiana, 
Missouri and Tennessee) within 50 km of Arkansas' border are below the 
2010 1-hour SO2 NAAQS; and
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    \9\ The Air Quality System (AQS) contains ambient air pollution 
data collected by EPA, state, local, and tribal air pollution 
control agencies from over thousands of monitors. AQS also contains 
meteorological data, descriptive information about each monitoring 
station (including its geographic location and its operator), and 
data quality assurance/quality control information. AQS data is used 
to assess air quality, assist in attainment/non-attainment 
designations, evaluate State Implementation Plans for non-attainment 
areas, perform modeling for permit review analysis, and prepare 
reports for congress as mandated by the Clean Air Act.
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     Available modeling for DRR sources within 50 km of 
Arkansas' border both within the State and in neighboring states 
demonstrates that Arkansas' larger point sources of SO2 do 
not interfere with maintenance of the 2010 1-hour SO2 NAAQS 
in another state.
    Based on the analysis provided by Arkansas in its SIP submittal, 
EPA's summary of its evaluation, and EPA's supplemental Prong 2 
analysis given in the Technical Support Document (TSD) for this action, 
EPA proposes to find that sources within Arkansas will not interfere 
with maintenance of the 2010 1-hour SO2 NAAQS in any other 
state.

III. Proposed Action

    EPA is proposing to approve the remaining portions of the Arkansas' 
March 24, 2017 SIP submittal addressing interstate transport for the 
2010 1-hour SO2 NAAQS as these portions meet the 
requirements in section 110(a)(2)(i)(I) of the CAA. Based on the EPA's 
analysis of the state's submittal and the factors described in this 
document and the TSD, EPA proposes to determine Arkansas' SIP contains 
adequate provisions to ensure that air emissions within Arkansas will 
not contribute significantly to nonattainment or interfere with 
maintenance of the 2010 1-hour SO2 NAAQS in any other state.

IV. 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. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, the EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, 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 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 rule, addressing Arkansas' interstate 
transport requirements for the 2010 1-hour SO2 NAAQS, does 
not have tribal implications as specified by Executive Order 13175 (65 
FR 67249, November 9, 2000), because the SIP is not approved to apply 
in Indian country located in the state, and EPA notes that it 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, Sulfur oxides.

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


    Dated: August 1, 2019.
David Gray,
Acting Regional Administrator, Region 6.
[FR Doc. 2019-16936 Filed 8-7-19; 8:45 am]
 BILLING CODE 6560-50-P


