[Federal Register Volume 82, Number 102 (Tuesday, May 30, 2017)]
[Proposed Rules]
[Pages 24636-24651]
[FR Doc No: 2017-10914]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R04-OAR-2017-0085; FRL-9962-26-Region 4]

Air Plan Approval and Air Quality Designation; TN; Redesignation
of the Knoxville 1997 Annual PM2.5 Nonattainment Area to Attainment

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: On December 20, 2016, Tennessee, through the Tennessee
Department of Environment and Conservation (TDEC), submitted a request
for the Environmental Protection Agency (EPA) to redesignate the
Knoxville-Sevierville-La Follette, TN fine particulate matter
(PM2.5) nonattainment area (hereinafter referred to as the
``Knoxville Area'' or ``Area'') to attainment for the 1997 Annual
PM2.5 national ambient air quality standards (NAAQS) and to
approve a state implementation plan (SIP) revision containing a
maintenance plan, a reasonably available control measures (RACM)
determination, and source-specific requirements for the Area. EPA is
proposing to approve Tennessee's RACM determination for the Knoxville
Area and incorporate it into the SIP; to incorporate source-specific
requirements for two sources in the Area into the SIP; determine that
the Knoxville Area is attaining the 1997 Annual PM2.5 NAAQS
based on 2013-2015 data; approve Tennessee's plan for maintaining the
1997 Annual PM2.5 NAAQS for the Knoxville Area (maintenance
plan), including the associated motor vehicle emission budgets (MVEBs)
for nitrogen oxides (NOX) and PM2.5 for the years
2014 and 2028, and incorporate it into the SIP; and to redesignate the
Knoxville Area to attainment for the 1997 Annual PM2.5
NAAQS.

DATES: Comments must be received on or before June 29, 2017.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2017-0085 at http://www.regulations.gov. Follow the online
instructions for submitting comments. Once submitted, comments cannot
be edited or removed from Regulations.gov. EPA may publish any comment
received to its public docket. Do not submit electronically any
information you consider to be Confidential Business Information (CBI)
or other information whose disclosure is restricted by statute.
Multimedia submissions (audio, video, etc.) must be accompanied by a
written comment. The written comment is considered the official comment
and should include discussion of all points you wish to make. EPA will
generally not consider comments or comment contents located outside of
the primary submission (i.e., on the web, cloud, or other file sharing
system). For additional submission methods, the full EPA public comment
policy, information about CBI or multimedia submissions, and general
guidance on making effective comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Sean Lakeman of the Air Regulatory
Management Section, in the 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. Sean Lakeman may be reached by phone at<PHONE_NUMBER>, or
via electronic mail at<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Table of Contents

I. What are the actions EPA is proposing to take?
II. What is the background for EPA's proposed actions?
III. What are the criteria for redesignation?
IV. Why is EPA proposing these actions?
V. What is EPA's analysis of the request?
VI. What is EPA's analysis of the proposed NOX and
PM2.5 MVEBs for the Knoxville area?
VII. What is the effect of EPA's proposed actions?
VIII. Proposed Actions
IX. Statutory and Executive Order Reviews

I. What are the actions EPA is proposing to take?

    EPA is proposing to take the following separate but related
actions: (1) To approve Tennessee's RACM determination for the
Knoxville Area pursuant to Clean Air Act (CAA or Act) sections
172(c)(1) and 189(a)(1)(C) and incorporate it into the SIP; (2) to

determine that the Knoxville Area is attaining the 1997 Annual
PM2.5 NAAQS based on 2013-2015 data; (3) to approve
Tennessee's plan for maintaining the 1997 Annual PM2.5 NAAQS
(maintenance plan) including the associated MVEBs for the Knoxville
Area and incorporate it into the SIP; (4) to incorporate source-
specific requirements for two sources in the Area into the SIP; and (5)
to redesignate the Knoxville Area to attainment for the 1997 Annual
PM2.5 NAAQS. EPA has already made its determination on the
adequacy of the 2014 and 2028 MVEBs for the Knoxville Area for
transportation conformity purposes and notified the public of that
determination through publication of the Notice of Adequacy on March
10, 2017. See 82 FR 13337. These MVEBs were effective on March 27,
2017.\1\ The Knoxville Area consists of Anderson, Blount, Knox, and
Loudon Counties in their entirety and a portion of Roane County (the
area described by U.S. Census 2000 block group identifier 47-145-0307-
2). These proposed actions are summarized below and described in
greater detail throughout this notice of proposed rulemaking.
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    \1\ EPA issued a letter to the State on February 15, 2017,
finding the MVEBs adequate for transportation conformity purposes.
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    EPA's 1997 Annual PM2.5 nonattainment designation for
the Area triggered an obligation for Tennessee to develop a
nonattainment SIP revision addressing certain CAA requirements under
title I, part D, subpart 1 (hereinafter ``Subpart 1'') and title I,
part D, subpart 4 (hereinafter ``Subpart 4''). Subpart 1 contains the
general requirements for nonattainment areas for criteria pollutants,
including requirements to develop a SIP that provides for the
implementation of RACM under section 172(c)(1), requires reasonable
further progress (RFP), includes base-year and attainment-year
emissions inventories, and provides for the implementation of
contingency measures. As discussed in greater detail later in this
notice, Subpart 4 contains specific planning and scheduling
requirements for coarse particulate matter (PM10)
nonattainment areas, including requirements for new source review, RACM
(under section 189(a)(1)(C)), and RFP. In the General Preamble, EPA's
longstanding general guidance interpreting the 1990 amendments to the
CAA, EPA discussed the relationship of Subpart 1 and Subpart 4 SIP
requirements and pointed out that Subpart 1 requirements were to an
extent ``subsumed by, or integrally related to, the more specific PM-10
requirements.'' See 57 FR 13538 (April 16, 1992). Under the United
States Court of Appeals for the District of Columbia Circuit's (D.C.
Circuit's) January 4, 2013, decision in Natural Resources Defense
Council v. EPA, 706 F.3d 428 (D.C. Cir. 2013), Subpart 4 requirements
apply to PM2.5 nonattainment areas.\2\
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    \2\ In explaining its decision, the Court reasoned that the
plain meaning of the CAA requires implementation of the 1997
PM2.5 NAAQS under Subpart 4 because PM2.5
particles fall within the statutory definition of PM10
and are thus subject to the same statutory requirements. EPA
finalized its interpretation of Subpart 4 requirements as applied to
the PM2.5 NAAQS in its final rule entitled ``Air Quality
State Implementation Plans; Approvals and Promulgations: Fine
Particulate Matter National Ambient Air Quality Standards'' (81 FR
58010, August 24, 2016).
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    On June 2, 2014, EPA published a rule entitled ``Identification of
Nonattainment Classification and Deadlines for Submission of State
Implementation Plan (SIP) Provisions for the 1997 Fine Particle
(PM2.5) National Ambient Air Quality Standard (NAAQS) and
2006 PM2.5 NAAQS'' (``Classification and Deadlines Rule'').
See 79 FR 31566. In that rule, the Agency responded to the D.C.
Circuit's January 2013 decision by identifying all PM2.5
nonattainment areas for the 1997 and 2006 PM2.5 NAAQS as
``moderate'' nonattainment areas under Subpart 4, and by establishing a
new SIP submission date of December 31, 2014, for moderate area
attainment plans and for any additional attainment-related or
nonattainment new source review plans necessary for areas to comply
with the requirements applicable under subpart 4. Id. at 31567-70.
    Based on its moderate nonattainment area classification, Tennessee
was required to submit a SIP revision addressing RACM pursuant to CAA
section 172(c)(1) and section 189(a)(1)(C) for the Area. Although EPA
does not believe that section 172(c)(1) and section 189(a)(1)(C) RACM
must be approved into a SIP prior to redesignation of an area to
attainment once that area is attaining the NAAQS, EPA is proposing to
approve Tennessee's RACM determination and incorporate it into its SIP
pursuant to a recent decision by the United States Court of Appeals for
the Sixth Circuit (Sixth Circuit) in Sierra Club v. EPA, 793 F.3d 656
(6th Cir. 2015), as discussed in Section V.A, below.\3\
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    \3\ On August 2, 2012, EPA published a final determination that
the Area had attained the 1997 Annual PM2.5 NAAQS based
on ambient air monitoring data for the 2009-2011 time period. See 77
FR 45954. In that determination and in accordance with EPA's clean
data policy, EPA suspended the requirements for the Area to submit a
SIP revision addressing RACM, RFP plans, contingency measures, and
certain other attainment planning requirements so long as the Area
continues to attain the 1997 Annual PM2.5 NAAQS. EPA
notes, however, that in 2013 it issued results of a technical
systems audit on the PM2.5 laboratory in Tennessee that
invalidated all 2010-2012 PM2.5 monitoring data for the
Area. After the monitoring audit issues were addressed, Tennessee
submitted valid data for all sites, resulting in complete and valid
design values using 2013-2015 data.
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    EPA is proposing to determine that the Knoxville Area is attaining
the 1997 Annual PM2.5 NAAQS based on recent air quality
data. EPA also proposes to approve Tennessee's maintenance plan for the
Knoxville Area as meeting the requirements of section 175A (such
approval being one of the CAA) criteria for redesignation to attainment
status) and incorporate it into the SIP. The maintenance plan is
designed to help keep the Knoxville Area in attainment for the 1997
Annual PM2.5 NAAQS through 2028. The maintenance plan
includes 2014 and 2028 MVEBs for NOX and direct
PM2.5 for the Knoxville Area. EPA is proposing to approve
these MVEBs and incorporate them into the Tennessee SIP. EPA is also
proposing to incorporate source-specific requirements for two sources
located in the Area--the Tennessee Valley Authority (TVA) Bull Run
Fossil Plant and TVA Kingston Fossil Plant--into the SIP. The specific
requirements proposed for incorporation are discussed in Section V.A,
below.
    EPA also proposes to determine that the Knoxville Area has met the
requirements for redesignation under section 107(d)(3)(E) of the CAA.
Accordingly, in this action, EPA is proposing to approve a request to
change the legal designation of Anderson, Blount, Knox, and Loudon
Counties and a portion of Roane County within the Knoxville Area, as
found at 40 CFR part 81, from nonattainment to attainment for the 1997
Annual PM2.5 NAAQS.
    In summary, this proposed rulemaking is in response to Tennessee's
December 20, 2016, redesignation request and associated SIP submission
that address the specific issues summarized above and the necessary
elements for redesignation described in section 107(d)(3)(E) of the CAA
for the redesignation of the Knoxville Area to attainment for the 1997
Annual PM2.5 NAAQS.

II. What is the background for EPA's proposed actions?

    Fine particle pollution can be emitted directly or formed
secondarily in the atmosphere.\4\ The main precursors of

secondary PM2.5 are sulfur dioxide (SO2),
NOX, ammonia, and volatile organic compounds (VOCs). See 81
FR 58010, 58014 (August 24, 2016). Sulfates are a type of secondary
particle formed from SO2 emissions from power plants and
industrial facilities. Nitrates, another common type of secondary
particle, are formed from NOX emissions from power plants,
automobiles, and other combustion sources.
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    \4\ Fine particulate matter (PM2.5) refers to
airborne particles less than or equal to 2.5 micrometers in
diameter. Although treated as a single pollutant, fine particles
come from many different sources and are composed of many different
compounds. In the Knoxville Area, one of the sources of
PM2.5 is fuel burning sources (such as coal-burning power
plants, motor vehicles and combustion operations). VOC, also
precursors for PM, are emitted from a variety of sources, including
motor vehicles, chemical plants, refineries, factories, consumer and
commercial products, and other industrial sources. VOC are also
emitted by natural sources such as vegetation.
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    On July 18, 1997, EPA promulgated the first air quality standards
for PM2.5. EPA promulgated an annual standard at a level of
15.0 micrograms per cubic meter ([mu]g/m\3\), based on a 3-year average
of annual mean PM2.5 concentrations. In the same rulemaking,
EPA promulgated a 24-hour standard of 65 [mu]g/m\3\, based on a 3-year
average of the 98th percentile of 24-hour concentrations. On October
17, 2006 (71 FR 61144), EPA retained the annual average NAAQS at 15.0
[mu]g/m\3\ but revised the 24-hour NAAQS to 35 [mu]g/m\3\, based again
on the 3-year average of the 98th percentile of 24-hour
concentrations.\5\ Under EPA regulations at 40 CFR part 50, the primary
and secondary 1997 Annual PM2.5 NAAQS are attained when the
annual arithmetic mean concentration, as determined in accordance with
40 CFR part 50, Appendix N, is less than or equal to 15.0 [mu]g/m\3\ at
all relevant monitoring sites in the subject area averaged over a 3-
year period.
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    \5\ In response to legal challenges of the annual standard
promulgated in 2006, the D.C. Circuit remanded that NAAQS to EPA for
further consideration. See American Farm Bureau Federation and
National Pork Producers Council, et al. v. EPA, 559 F.3d 512 (D.C.
Cir. 2009). However, given that the 1997 and 2006 Annual NAAQS are
essentially identical, attainment of the 1997 Annual NAAQS would
also indicate attainment of the remanded 2006 Annual NAAQS.
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    On January 5, 2005, at 70 FR 944, and supplemented on April 14,
2005, at 70 FR 19844, EPA designated the Knoxville Area as
nonattainment for the 1997 Annual PM2.5 NAAQS. All 1997
PM2.5 NAAQS areas were designated under Subpart 1. Subpart 1
contains the general requirements for nonattainment areas for any
pollutant governed by a NAAQS and is less prescriptive than the other
subparts of title I, part D. On April 25, 2007 (72 FR 20586), EPA
promulgated its Clean Air Fine Particle Implementation Rule, codified
at 40 CFR part 51, subpart Z, in which the Agency provided guidance for
state and tribal plans to implement the 1997 PM2.5 NAAQS.
The D.C. Circuit remanded the Clean Air Fine Particle Implementation
Rule and the final rule entitled ``Implementation of the New Source
Review (NSR) Program for Particulate Matter Less than 2.5 Micrometers
(PM2.5)'' (73 FR 28321, May 16, 2008) (collectively, ``1997
PM2.5 Implementation Rules'') to EPA on January 4, 2013, in
Natural Resources Defense Council v. EPA, 706 F.3d 428 (D.C. Cir.
2013). The Court found that EPA erred in implementing the 1997
PM2.5 NAAQS pursuant to the general implementation
provisions of Subpart 1, rather than the particulate matter-specific
provisions of Subpart 4.
    On July 29, 2016, EPA issued a rule entitled, ``Fine Particulate
Matter National Ambient Air Quality Standards: State Implementation
Plan Requirements'' (PM2.5 SIP Requirements Rule) that
clarifies how states should meet the statutory SIP requirements that
apply to areas designated nonattainment for any PM2.5 NAAQS
under Subparts 1 and 4. See 81 FR 58010 (August 24, 2016). It does so
by establishing regulatory requirements and providing guidance that is
applicable to areas that are currently designated nonattainment for
existing PM2.5 NAAQS and areas that are designated
nonattainment for any PM2.5 NAAQS in the future. In
addition, the rule responds to the D.C. Circuit's remand of the 1997
PM2.5 Implementation Rules. As a result, the requirements of
the rule also govern future actions associated with states' ongoing
implementation efforts for the 1997 and 2006 PM2.5 NAAQS.
    In the PM2.5 SIP Requirements Rule, EPA revoked the 1997
primary Annual PM2.5 NAAQS in areas that had always been
attainment for that NAAQS, and in areas that had been designated as
nonattainment but that were redesignated to attainment before October
24, 2016, the rule's effective date. See 81 FR 58010 (August 24, 2016).
EPA also finalized a provision that revokes the 1997 primary Annual
PM2.5 NAAQS in areas that are redesignated to attainment for
that NAAQS after October 24, 2016, effective on the effective date of
the redesignation of the area to attainment for that NAAQS. See 40 CFR
50.13(d).
    EPA is proposing to redesignate the Knoxville Area to attainment
for the 1997 Annual PM2.5 NAAQS and proposing to approve the
CAA section 175A maintenance plan for the 1997 Annual PM2.5
NAAQS for the reasons described elsewhere in this notice.\6\ If the
proposal is finalized, the 1997 primary Annual PM2.5 NAAQS
will be revoked in the Area on the effective date of the redesignation.
Beginning on that date, the Area will no longer be subject to
transportation or general conformity requirements for the 1997 Annual
PM2.5 NAAQS due to the revocation of the primary NAAQS. See
81 FR 58125. The Area will be required to implement the CAA section
175A maintenance plan for the 1997 Annual PM2.5 NAAQS and
the prevention of significant deterioration (PSD) program for the 1997
Annual PM2.5 NAAQS. Once approved, the maintenance plan can
only be revised if the revision meets the requirements of CAA section
110(l) and, if applicable, CAA section 193. The Area would not be
required to submit a second 10-year maintenance plan for the 1997
Annual PM2.5 NAAQS. See 81 FR 58144.
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    \6\ CAA section 175A(a) establishes the requirements that must
be fulfilled by nonattainment areas in order to be redesignated to
attainment. That section only requires that nonattainment areas for
the primary standard submit a plan addressing maintenance of the
primary NAAQS in order to be redesignated to attainment; it does not
require nonattainment areas for secondary NAAQS to submit
maintenance plans in order to be redesignated to attainment.
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III. What are the criteria for redesignation?

    The CAA provides the requirements for redesignating a nonattainment
area to attainment. Specifically, section 107(d)(3)(E) of the CAA
allows for redesignation provided the following criteria are met: (1)
The Administrator determines that the area has attained the applicable
NAAQS; (2) the Administrator has fully approved the applicable
implementation plan for the area under section 110(k); (3) the
Administrator determines that the improvement in air quality is due to
permanent and enforceable reductions in emissions resulting from
implementation of the applicable SIP and applicable federal air
pollutant control regulations, and other permanent and enforceable
reductions; (4) the Administrator has fully approved a maintenance plan
for the area as meeting the requirements of section 175A; and (5) the
state containing such area has met all requirements applicable to the
area under section 110 and part D of title I of the CAA.
    On April 16, 1992, EPA provided guidance on redesignation in the
General Preamble for the Implementation of title I of the CAA
Amendments of 1990 (57 FR 13498), and the Agency supplemented this
guidance on April 28, 1992 (57 FR 18070). EPA has provided further
guidance on processing redesignation requests in the following
documents:

    1. ``Procedures for Processing Requests to Redesignate Areas to
Attainment,'' Memorandum from John Calcagni, Director, Air Quality
Management Division, September 4, 1992 (hereinafter referred to as
the ``Calcagni Memorandum'');
    2. ``State Implementation Plan (SIP) Actions Submitted in
Response to Clean Air Act (CAA) Deadlines,'' Memorandum from John
Calcagni, Director, Air Quality Management Division, October 28,
1992; and
    3. ``Part D New Source Review (Part D NSR) Requirements for
Areas Requesting Redesignation to Attainment,'' Memorandum from Mary
D. Nichols, Assistant Administrator for Air and Radiation, October
14, 1994 (hereinafter referred to as the ``Nichols Memorandum'').

IV. Why is EPA proposing these actions?

    On December 20, 2016, Tennessee requested that EPA redesignate the
Knoxville Area to attainment for the 1997 Annual PM2.5 NAAQS
and submitted an associated SIP revision containing a maintenance plan,
a RACM determination, and source-specific requirements for two sources
in the Area. EPA's evaluation indicates that the RACM determination and
source-specific requirements meet the relevant requirements of the CAA
and that the Knoxville Area meets the requirements for redesignation
set forth in section 107(d)(3)(E), including the maintenance plan
requirements under section 175A of the CAA. As a result of these
proposed findings, EPA is proposing to take the separate but related
actions summarized in section I of this notice.

V. What is EPA's analysis of the request?

    As stated above, in accordance with the CAA, EPA proposes to: (1)
To approve Tennessee's RACM determination for the Knoxville Area and
incorporate it into the SIP; (2) to determine that the Area is
attaining the 1997 Annual PM2.5 NAAQS based on 2013-2015
data; (3) to approve Tennessee's plan for maintaining the 1997 Annual
PM2.5 NAAQS (maintenance plan), including the associated
MVEBs for the Knoxville Area, and incorporate it into the Tennessee
SIP; (4) to incorporate source-specific requirements for two sources in
the Area into the SIP; and (5) to redesignate the Knoxville Area to
attainment for the 1997 Annual PM2.5 NAAQS.

A. RACM Determination

1. Relationship Between RACM and Redesignation Criteria
    As noted above, there are a number of planning requirements in the
CAA that are designed to help areas achieve attainment or demonstrate
progress toward attainment. Where those areas are already attaining the
NAAQS in question, EPA has long interpreted these requirements as not
applicable for purposes of evaluating whether an area has a fully
approved SIP pursuant to CAA section 107(d)(3)(E)(ii). See, e.g., 57 FR
13498, 13564 (April 16, 1992); Calcagni Memorandum. Included in this
category of suspended or inapplicable planning requirements are the
provisions in Subparts 1 and 4 requiring areas to submit plans
providing for implementation of RACM, including reasonably available
control technology (RACT). However, in Sierra Club v. EPA, the Sixth
Circuit vacated EPA's redesignation of the Indiana and Ohio portions of
the Cincinnati-Hamilton nonattainment area to attainment for the 1997
PM2.5 NAAQS because EPA had not yet approved Subpart 1 RACM
for the Cincinnati Area into the Indiana and Ohio SIPs. The Court
concluded that ``a State seeking redesignation `shall provide for the
implementation' of RACM/RACT, even if those measures are not strictly
necessary to demonstrate attainment with the PM2.5 NAAQS. .
. . If the State has not done so, EPA cannot `fully approve' the area's
SIP, and redesignation to attainment status is improper.'' Sierra Club,
793 F.3d at 670.
    EPA is bound by the Sixth Circuit's decision in Sierra Club v. EPA
within the Court's jurisdiction.\7\ Therefore, EPA is proposing to
approve Tennessee's RACM determination into the SIP in conjunction with
its proposal to approve the State's redesignation request for the Area
pursuant to the Court's decision.\8\
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    \7\ The states of Kentucky, Michigan, Ohio, and Tennessee are
located within the Sixth Circuit's jurisdiction.
    \8\ The EPA Region 4 Regional Administrator signed a memorandum
on July 20, 2015, seeking concurrence from the Director of EPA's Air
Quality Policy Division (AQPD) in the Office of Air Quality Planning
and Standards to act inconsistent with EPA's interpretation of CAA
sections 107(d)(3)(E) and 172(c)(1) when taking action on pending
and future redesignation requests in Kentucky and Tennessee because
the Region is bound by the Sixth Circuit's decision in Sierra Club
v. EPA. The AQPD Director issued her concurrence on July 22, 2015.
This memorandum is not required to satisfy EPA's regional
consistency regulations. See 40 CFR 56.5(b)(1); 81 FR 51102 (August
3, 2016).
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2. Proposed Approval of Tennessee's RACM Determination
    Subpart 1 requires that each attainment plan ``provide for the
implementation of all reasonably available control measures as
expeditiously as practicable (including such reductions in emission
from the existing sources in the area as may be obtained through the
adoption, at a minimum, of reasonably available control technology),
and shall provide for attainment of the national primary ambient air
quality standards.'' See CAA section 172(c)(1). The attainment planning
requirements in Subpart 4 that are specific to PM10
(including PM2.5) likewise impose upon states an obligation
to develop attainment plans that require RACM for sources of direct
PM2.5 and PM2.5 precursors within a moderate
nonattainment area. CAA section 189(a)(1)(C) requires that states with
a moderate PM2.5 nonattainment area have attainment plan
provisions to assure that RACM is implemented by no later than four
years after designation of the area.\9\
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    \9\ States with areas later reclassified as ``serious''
nonattainment areas under Subpart 4 must also develop and submit
later plans to meet additional requirements for serious areas. See
40 CFR 51.1003(b).
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    EPA reads CAA sections 172(c)(1) and 189(a)(1)(C), and EPA's
implementing regulations, together to require that attainment plans for
moderate nonattainment areas must provide for the implementation of
RACM for existing sources of PM2.5 and PM2.5
precursors in the nonattainment area as expeditiously as practicable
but no later than four years after designation.\10\ As set forth in 40
CFR 51.1009(a)(4), states are required to adopt and implement all
technologically and economically feasible control measures for PM and
its precursors that are necessary to bring a moderate nonattainment
area into attainment by its attainment date or that would advance
attainment by one year. If a state demonstrates that a control measure
would not be necessary for attaining the standard as expeditiously as
practicable or would not advance the attainment date, the state is not
required to adopt such measure into its SIP. 40 CFR 51.1009(a)(4)(i)(A)
further specifies that those measures that are identified for adoption
and implementation constitute RACM for the area. Therefore, any measure
that is not necessary for the area to achieve attainment or does not
advance attainment by one year does not constitute RACM.\11\
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    \10\ This interpretation is consistent with guidance described
in the General Preamble. See 57 FR 13498, 13540 (April 16, 1992).
For further discussion, see 81 FR 58010, 58035 (August 24, 2016).
    \11\ Reviewing courts have upheld EPA's interpretation of RACM
as encompassing only those measures necessary to advance attainment.
See Sierra Club v. EPA, 314 F.3d 735, 743-745 (5th Cir. 2002);
Sierra Club v. EPA, 294 F.3d 155, 162-163 (D.C. Cir. 2002); NRDC v.
EPA, 571 F.3d 1245, 1252 (D.C. Cir. 2009).
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    In this action, EPA proposes to approve Tennessee's December 20,
2016 RACM submission. In that submission, Tennessee did not identify
any

measures necessary to bring the Area into attainment, nor any measures
that would advance attainment of the Area, because the Area is already
attaining the 1997 Annual PM2.5 NAAQS. Because only those
measures that are necessary to attain by the attainment date or would
advance attainment by one year constitute RACM under CAA sections
172(c)(1), 189(a)(1), and EPA's implementing regulations, EPA proposes
to approve Tennessee's determination that no additional measures are
necessary to meet the State's obligations to have fully adopted RACM
under the CAA and under the Sixth Circuit's decision in Sierra Club.

B. Redesignation Request and Maintenance Demonstration

    The five redesignation criteria provided under CAA section
107(d)(3)(E) are discussed in greater detail for the Area in the
following paragraphs of this section.
Criteria (1)--The Knoxville Area Has Attained the 1997 Annual
PM2.5 NAAQS
    For redesignating a nonattainment area to attainment, the CAA
requires EPA to determine that the area has attained the applicable
NAAQS (CAA section 107(d)(3)(E)(i)). For PM2.5, an area may
be considered to be attaining the 1997 Annual PM2.5 NAAQS if
it meets the standards, as determined in accordance with 40 CFR 50.13
and Appendix N of part 50, based on three complete, consecutive
calendar years of quality-assured air quality monitoring data. To
attain the 1997 Annual PM2.5 NAAQS, the 3-year average of
the annual arithmetic mean concentration, as determined in accordance
with 40 CFR part 50, Appendix N, must be less than or equal to 15.0
[mu]g/m\3\ at all relevant monitoring sites in the subject area over a
3-year period. The relevant data must be collected and quality-assured
in accordance with 40 CFR part 58 and recorded in the EPA Air Quality
System (AQS) database. The monitors generally should have remained at
the same location for the duration of the monitoring period required
for demonstrating attainment.
    EPA has evaluated the complete, quality-assured data for the Area
from 2013-2015, and as shown in Table 1 below, the monitors in the
Knoxville Area all have annual arithmetic mean PM2.5
concentrations averaged over three years (i.e., design values) that are
attaining the 1997 Annual PM2.5 NAAQS.

   Table 1--Knoxville Area 2013-2015 Design Values for the 1997 Annual
                               PM2.5 NAAQS
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                                                             2013-2015
              Monitor site                    Site ID      Design value
                                                           ([mu]g/m\3\)
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Sequoyah Ave, Maryville.................       470090011             8.6
Bearden Middle School...................       470930028             9.2
Davanna Street, Air Lab.................       470931013             9.9
Rule High School........................       470931017             9.9
Spring Hill Elementary School...........       470931020             9.1
Loudon Pope site........................       471050108             9.4
Harriman High School....................       471450004             8.7
------------------------------------------------------------------------

    As shown in Table 1, above, the Knoxville Area has a 2013-2015
design value of 9.9 [mu]g/m\3\, which is below the 1997 Annual
PM2.5 NAAQS. Therefore, EPA has preliminarily concluded that
the Knoxville Area meets the 1997 Annual PM2.5 NAAQS of 15.0
[micro]g/m\3\ for the period 2013-2015, the most recent 3-year period
of certified data availability. For this proposed action, EPA has also
reviewed the preliminary 2014-2016 design values for the Area and
proposes to find that the preliminary data does not indicate a
violation of the NAAQS.\12\ EPA will not take final action to approve
the redesignation if the 3-year design value exceeds the NAAQS prior to
EPA finalizing the redesignation. As discussed in more detail below,
Tennessee has committed to continue monitoring in the Knoxville Area in
accordance with 40 CFR part 58.
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    \12\ This preliminary data is available at EPA's air data Web
site: http://aqsdr1.epa.gov/aqsweb/aqstmp/airdata/download_files.html#Daily.
---------------------------------------------------------------------------

Criteria (2)--Tennessee Has a Fully Approved SIP Under Section 110(k)
for the Knoxville Area and Criteria (5)--Tennessee Has Met All
Applicable Requirements Under Section 110 and Part D of the CAA
    For redesignating a nonattainment area to attainment, the CAA
requires EPA to determine that the state has met all applicable
requirements under section 110 and part D of title I of the CAA (CAA
section 107(d)(3)(E)(v)) and that the state has a fully approved SIP
under section 110(k) for the area (CAA section 107(d)(3)(E)(ii)). EPA
proposes to find that Tennessee has met all applicable SIP requirements
for the Knoxville Area under section 110 of the CAA (general SIP
requirements) for purposes of redesignation. Additionally, EPA proposes
to find that Tennessee has met all applicable SIP requirements for
purposes of redesignation under part D of title I of the CAA in
accordance with section 107(d)(3)(E)(v). Further, EPA proposes to
determine that the SIP is fully approved with respect to all
requirements applicable for purposes of redesignation in accordance
with section 107(d)(3)(E)(ii) if EPA takes final action to incorporate
Tennessee's RACM determination into the SIP pursuant to the Sixth
Circuit's decision in Sierra Club v. EPA. In making these
determinations, EPA ascertained which requirements are applicable to
the Area and, if applicable, that they are fully approved under section
110(k). SIPs must be fully approved only with respect to requirements
that were applicable prior to submittal of the complete redesignation
request.
a. Tennessee Has Met All Applicable Requirements Under Section 110 and
Part D of the CAA
    General SIP requirements. General SIP elements and requirements are
delineated in section 110(a)(2) of title I, part A of the CAA. These
requirements include, but are not limited to, the following: Submittal
of a SIP that has been adopted by the state after reasonable public
notice and hearing; provisions for establishment and operation of
appropriate procedures needed to monitor ambient air quality;
implementation of a source permit program; provisions for the
implementation of part C requirements (Prevention of Significant
Deterioration (PSD)) and provisions for the

implementation of part D requirements (NNSR permit programs);
provisions for air pollution modeling; and provisions for public and
local agency participation in planning and emission control rule
development.
    Section 110(a)(2)(D) requires that SIPs contain certain measures to
prevent sources in a state from significantly contributing to air
quality problems in another state. To implement this provision, EPA has
required certain states to establish programs to address the interstate
transport of air pollutants. The section 110(a)(2)(D) requirements for
a state are not linked with a particular nonattainment area's
designation and classification in that state. EPA believes that the
requirements linked with a particular nonattainment area's designation
and classifications are the relevant measures to evaluate in reviewing
a redesignation request. The transport SIP submittal requirements,
where applicable, continue to apply to a state regardless of the
designation of any one particular area in the state. Thus, EPA does not
believe that the CAA's interstate transport requirements should be
construed to be applicable requirements for purposes of redesignation.
    In addition, EPA believes that other section 110 elements that are
neither connected with nonattainment plan submissions nor linked with
an area's attainment status are not applicable requirements for
purposes of redesignation. The area will still be subject to these
requirements after the area is redesignated. The section 110 and part D
requirements which are linked with a particular area's designation and
classification are the relevant measures to evaluate in reviewing a
redesignation request. This approach is consistent with EPA's existing
policy on applicability (i.e., for redesignations) of conformity and
oxygenated fuels requirements, as well as with section 184 ozone
transport requirements. See Reading, Pennsylvania, proposed and final
rulemakings (61 FR 53174-53176, October 10, 1996), (62 FR 24826, May 7,
1997); Cleveland-Akron-Loraine, Ohio, final rulemaking (61 FR 20458,
May 7, 1996); and Tampa, Florida, final rulemaking at (60 FR 62748,
December 7, 1995). See also the discussion on this issue in the
Cincinnati, Ohio, redesignation (65 FR 37879, June 19, 2000), and in
the Pittsburgh, Pennsylvania, redesignation (66 FR 53094, October 19,
2001).
    EPA has reviewed Tennessee's SIP and has preliminarily concluded
that it meets the general SIP requirements under section 110(a)(2) of
the CAA to the extent they are applicable for purposes of
redesignation. EPA has previously approved provisions of Tennessee's
SIP addressing CAA section 110(a)(2) requirements including provisions
addressing the 1997 Annual PM2.5 NAAQS. See 77 FR 45958
(August 2, 2012), 78 FR 18241 (March 26, 2013), and 79 FR 26143 (May 7,
2014). These requirements are, however, statewide requirements that are
not linked to the PM2.5 nonattainment status of the Area.
Therefore, EPA believes these SIP elements are not applicable for
purposes of this redesignation.
    Title I, part D, applicable SIP requirements. EPA proposes to
determine that Tennessee meets the applicable SIP requirements for the
Knoxville Area for purposes of redesignation under part D of the CAA.
Subpart 1 of part D, comprised of sections 172-179B of the CAA, sets
forth the basic nonattainment requirements applicable to all
nonattainment areas. For purposes of evaluating this redesignation
request, the applicable Subpart 1 SIP requirements are contained in
section 172(c) and in section 176. A thorough discussion of the
requirements contained in sections 172 and 176 can be found in the
General Preamble for Implementation of Title I. See 57 FR 13498 (April
16, 1992). Subpart 4, found in section 189, sets forth additional
nonattainment requirements for particulate matter nonattainment areas.
    Subpart 1, section 172 Requirements Section 172(c) sets out general
nonattainment plan requirements. A thorough discussion of these
requirements can be found in the General Preamble. EPA's longstanding
interpretation of the nonattainment planning requirements of section
172 is that once an area is attaining the NAAQS, those requirements are
not ``applicable'' for purposes of CAA section 107(d)(3)(E)(ii) and
therefore need not be approved into the SIP before EPA can redesignate
the area. In the General Preamble, EPA set forth its interpretation of
applicable requirements for purposes of evaluating redesignation
requests when an area is attaining a standard. See 57 FR at 13564. EPA
noted that the requirements for RFP and other measures designed to
provide for an area's attainment do not apply in evaluating
redesignation requests because those nonattainment planning
requirements ``have no meaning'' for an area that has already attained
the standard. Id. This interpretation is also set forth in the Calcagni
Memorandum.
    EPA's understanding of section 172 also forms the basis of its
Clean Data Policy. Under the Clean Data Policy, EPA promulgates a
determination of attainment, published in the Federal Register and
subject to notice-and-comment rulemaking, and this determination
formally suspends a state's obligation to submit most of the attainment
planning requirements that would otherwise apply, including an
attainment demonstration and planning SIPs to provide for RFP, RACM,
and contingency measures under section 172(c)(9). The Clean Data Policy
has been codified in regulations regarding the implementation of the
ozone and PM2.5 NAAQS. See e.g., 70 FR 71612 (November 29,
2005) and 72 FR 20586 (April 25, 2007).
    EPA's long-standing interpretation regarding the applicability of
the section 172(c) attainment planning requirements for an area that is
attaining a NAAQS applies in this proposed redesignation of the Area as
well, with the exception of the applicability of the requirement to
implement RACM under section 172(c)(1). As discussed above, the Sixth
Circuit ruled in Sierra Club that, in order to meet the requirement of
section 107(d)(3)(E)(ii), states are required to submit plans
addressing RACM under section 172(c)(1) and EPA is required to approve
those plans prior to redesignating an area, regardless of whether the
area is attaining the standard. Because Tennessee is within the Sixth
Circuit's jurisdiction, EPA is acting in accordance with the Sierra
Club decision by proposing to approve Tennessee's RACM determination
for the Area in parallel with this proposed redesignation action.
    Section 172(c)(1) requires the plans for all nonattainment areas to
provide for the implementation of RACM as expeditiously as practicable
and to provide for attainment of the primary NAAQS. Under this
requirement, a state must consider all available control measures,
including reductions that are available from adopting reasonably
available control technology on existing sources, for a nonattainment
area and adopt and implement such measures as are reasonably available
in the area as components of the area's attainment demonstration. As
discussed above, EPA is proposing to approve Tennessee's RACM
determination and incorporate it into the SIP.
    As noted above, the remaining section 172(c) attainment planning
requirements are not applicable for purposes of evaluating the State's
redesignation request. Specifically, the RFP requirement under section
172(c)(2), which is defined as progress that must be made toward
attainment, the requirement to submit section

172(c)(9) contingency measures, which are measures to be taken if the
area fails to make reasonable further progress to attainment, and the
section 172(c)(6) requirement that the SIP contain control measures
necessary to provide for attainment of the standard, are not applicable
requirements that Tennessee must meet here because the Area has
monitored attainment of the 1997 Annual PM2.5 NAAQS.
    Section 172(c)(3) requires submission and approval of a
comprehensive, accurate, and current inventory of actual emissions. On
August 21, 2012 (77 FR 50378), EPA approved Tennessee's 2002 base-year
emissions inventory for the Knoxville Area.
    Section 172(c)(4) requires the identification and quantification of
allowable emissions for major new and modified stationary sources to be
allowed in an area, and section 172(c)(5) requires source permits for
the construction and operation of new and modified major stationary
sources anywhere in the nonattainment area. EPA has determined that,
since PSD requirements will apply after redesignation, areas being
redesignated need not comply with the requirement that a NNSR program
be approved prior to redesignation, provided that the area demonstrates
maintenance of the NAAQS without NNSR. A more detailed rationale for
this view is described in the Nichols Memorandum. See also rulemakings
for the Illinois portion of the St. Louis Area (77 FR 34819, 34826,
June 12, 2012); Louisville, Kentucky (66 FR 53665, 53669, October 23,
2001); Grand Rapids, Michigan (61 FR 31831, 31834-31837, June 21,
1996); Cleveland-Akron-Lorain, Ohio (61 FR 20458, 20469-20470, May 7,
1996); Detroit, Michigan (60 FR 12459, 12467-12468, March 7, 1995).
Tennessee has demonstrated that the Knoxville Area will be able to
maintain the NAAQS without NNSR in effect, and therefore Tennessee need
not have fully approved NNSR programs prior to approval of the
redesignation request. Tennessee's PSD program will become effective in
the Knoxville Area upon redesignation to attainment.
    Section 172(c)(7) requires the SIP to meet the applicable
provisions of section 110(a)(2). As noted above, EPA believes that the
Tennessee SIP meets the requirements of section 110(a)(2) applicable
for purposes of redesignation.
    Subpart 1, section 176 Conformity Requirements. Section 176(c) of
the CAA requires states to establish criteria and procedures to ensure
that federally-supported or funded projects conform to the air quality
planning goals in the applicable SIP. The requirement to determine
conformity applies to transportation plans, programs and projects that
are developed, funded or approved under title 23 of the United States
Code (U.S.C.) and the Federal Transit Act (transportation conformity)
as well as to all other federally-supported or funded projects (general
conformity). State transportation conformity SIP revisions must be
consistent with federal conformity regulations relating to
consultation, enforcement and enforceability that EPA promulgated
pursuant to its authority under the CAA.
    EPA believes that it is reasonable to interpret the conformity SIP
requirements \13\ as not applying for purposes of evaluating the
redesignation request under section 107(d) because state conformity
rules are still required after redesignation and federal conformity
rules apply where state rules have not been approved. See Wall v. EPA,
265 F.3d 426 (6th Cir. 2001) (upholding this interpretation); 60 FR
62748 (December 7, 1995). Nonetheless, Tennessee has an approved
conformity SIP. See 78 FR 29027 (May 17, 2013).
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    \13\ CAA section 176(c)(4)(E) requires states to submit
revisions to their SIPs to reflect certain Federal criteria and
procedures for determining transportation conformity. Transportation
conformity SIPs are different from the MVEBs that are established in
control strategy SIPs and maintenance plans.
---------------------------------------------------------------------------

    Subpart 4 Requirements. As discussed above, in NRDC v. EPA, the
D.C. Circuit held that EPA should have implemented the 1997
PM2.5 NAAQS pursuant to the particulate matter-specific
provisions of Subpart 4. On remand, EPA identified all areas designated
nonattainment for either the 1997 or the 2006 PM2.5 NAAQS,
including the Knoxville Area, as moderate nonattainment areas for
purposes of Subpart 4 in the Classification and Deadlines Rule.
Moderate nonattainment areas are subject to the requirements of
sections 189(a), (c), and (e), including: (1) An approved permit
program for construction of new and modified major stationary sources
(section 189(a)(1)(A)); (2) an attainment demonstration (section
189(a)(1)(B)); (3) provisions for RACM (section 189(a)(1)(C)); (4)
quantitative milestones demonstrating RFP toward attainment by the
applicable attainment date (section 189(c)); and (5) precursor control
(section 189(e)).\14\
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    \14\ EPA's final implementation rule (81 FR 58010, August 24,
2016)) includes, among other things, the Agency's interpretation of
these moderate area requirements for purposes of PM2.5
NAAQS implementation.
---------------------------------------------------------------------------

    With respect to the specific attainment planning requirements under
Subpart 4,\15\ EPA applies the same interpretation that it applies to
attainment planning requirements under Subpart 1 or any of the other
pollutant-specific subparts. That is, under its long-standing
interpretation of the CAA, where an area is already attaining the
standard, EPA does not consider those attainment planning requirements
to be applicable for purposes of evaluating a request for
redesignation, that is, CAA section 107(d)(3)(E)(ii) or (v), because
requirements that are designed to help an area achieve attainment no
longer have meaning where an area is already meeting the standard. EPA
has proposed to determine that the Area has attained the 1997 Annual
PM2.5 standard. Therefore, under its longstanding
interpretation, EPA is proposing to determine that the requirements to
submit an attainment demonstration under section 189(a)(1)(B) and a RFP
demonstration under section 189(c)(1) are not applicable for purposes
of evaluating Tennessee's redesignation request. As discussed in
greater detail above, the Sixth Circuit's decision in Sierra Club
requires EPA to approve RACM under Subpart 1 prior to redesignation,
and EPA is bound by the Sixth Circuit's decision within its
jurisdiction. EPA therefore proposes to approve Tennessee's RACM
submittal for the Knoxville Area. Such approval, if finalized, would
also satisfy any similar obligation regarding Subpart 4 RACM.
---------------------------------------------------------------------------

    \15\ These planning requirements include the attainment
demonstration, quantitative milestone requirements, and RACM
analysis.
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    The permit requirements of Subpart 4, contained in section
189(a)(1)(A), refer to and apply the Subpart 1 permit provisions
requirements of sections 172 and 173 to PM10, without adding
to them. Consequently, EPA believes that section 189(a)(1)(A) does not
itself impose for redesignation purposes any additional requirements
for moderate areas beyond those contained in Subpart 1.\16\ As
discussed above, EPA has long relied on the interpretation that a fully
approved nonattainment new source review program is not considered an
applicable requirement for redesignation, provided the area can
maintain the standard with a PSD program after redesignation. A
detailed rationale for this view is described in the Nichols
Memorandum. See also rulemakings for the Illinois portion of the St.
Louis Area (77 FR 34819, 34826, June 12, 2012); Louisville, Kentucky
(66 FR 53665, 53669, October 23, 2001); Grand Rapids, Michigan (61 FR
31831,

31834-31837, June 21, 1996); Cleveland-Akron-Lorain, Ohio (61 FR 20458,
20469-20470, May 7, 1996); Detroit, Michigan (60 FR 12459, 12467-12468,
March 7, 1995).
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    \16\ The potential effect of section 189(e) on section
189(a)(1)(A) for purposes of evaluating this redesignation is
discussed below.
---------------------------------------------------------------------------

    Subpart 4 and the Control of PM2.5 Precursors. CAA
section 189(e) provides that control requirements for major stationary
sources of direct PM10 (including PM2.5) shall
also apply to PM precursors from those sources, except where EPA
determines that major stationary sources of such precursors ``do not
contribute significantly to PM10 levels which exceed the
standard in the area.'' The CAA does not explicitly address whether it
would be appropriate to include a potential exemption from precursor
controls for all source categories under certain circumstances. In
implementing Subpart 4 with regard to controlling PM10, EPA
permitted states to determine that a precursor was ``insignificant''
where the state could show in its attainment plan that it would
expeditiously attain without adoption of emission reduction measures
aimed at that precursor. This approach was upheld in Association of
Irritated Residents v. EPA, 423 F.3d 989 (9th Cir. 2005) and extended
to PM2.5 implementation in the PM Implementation Rule. A
state may develop its attainment plan and adopt reasonably available
control measures that target only those precursors that are necessary
to control for purposes of timely attainment. See 81 FR 58020. In the
rule, EPA also finalized application of 189(e) to the NNSR permitting
program, requiring states to determine whether a new major source of a
precursor might have a significant contribution to air quality before
allowing exemption of controls of a precursor from a new major
stationary source or major modification in the context of that program.
See 81 FR 58026.
    Therefore, because the requirement of section 189(e) is primarily
actionable in the context of addressing precursors in an attainment
plan and in NNSR permitting, a precursor exemption analysis under
section 189(e) and EPA's implementing regulations is not an applicable
requirement that needs to be fully approved in the context of a
redesignation under CAA section 107(d)(3)(E)(ii). As discussed above,
for areas that are attaining the standard, EPA does not interpret
attainment planning requirements of Subparts 1 and 4 to be applicable
requirements for the purposes of redesignating an area to attainment
nor does it interpret NNSR to be an applicable requirement if the area
can maintain the NAAQS with a PSD program after redesignation. However,
to the extent that Tennessee is required to conduct a precursor
exemption analysis in order to satisfy 189(e) in the context of its
RACM determination for the Knoxville Area, which is required pursuant
to the Sixth Circuit's decision in Sierra Club, EPA proposes to find
that the requirements of section 189(e), as interpreted by EPA's
regulations, are met in this case. The Area has expeditiously attained
the 1997 Annual PM2.5 NAAQS, and therefore, no additional
controls of any pollutant, including any PM2.5 precursor,
are necessary to bring the Area into attainment.\17\
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    \17\ EPA also notes that the Knoxville Area contains no major
stationary sources of ammonia; existing major stationary sources of
VOCs are adequately controlled under other provisions of the CAA
regulating the ozone NAAQS; and attainment in the Area is due to
permanent and enforceable emissions reductions on all precursors
necessary to provide for continued attainment. The Area has reduced
VOC emissions through the implementation of various control programs
including VOC RACT regulations and various on-road and non-road
motor vehicle control programs. Table 5, below, shows that future
VOC emissions are 12 percent below the attainment year emissions
level.
---------------------------------------------------------------------------

    For these reasons, EPA proposes to find that Tennessee has
satisfied all applicable requirements for purposes of redesignation of
the Knoxville Area under section 110 and part D of the CAA.
b. Tennessee Has a Fully-Approved Applicable SIP Under Section 110(k)
of the CAA
    EPA has fully approved the applicable Tennessee SIP for the
Knoxville Area under section 110(k) of the CAA for all requirements
applicable for purposes of redesignation with the exception of the RACM
requirements. In today's proposed action, EPA is proposing to approve
the RACM determination for the Area and incorporate it into the
Kentucky SIP. EPA may rely on prior SIP approvals in approving a
redesignation request (see Calcagni Memorandum at p. 3; Southwestern
Pennsylvania Growth Alliance v. Browner, 144 F.3d 984 (6th Cir. 1998;
Wall, 265 F.3d 426) plus any additional measures it may approve in
conjunction with a redesignation action. See 68 FR 25426 (May 12, 2003)
and citations therein. Following passage of the CAA of 1970, Tennessee
has adopted and submitted, and EPA has fully approved at various times,
provisions addressing the various SIP elements applicable for the 1997
Annual PM2.5 NAAQS in the Knoxville Area.
    As indicated above, EPA believes that the section 110 elements not
connected with nonattainment plan submissions and not linked to an
area's nonattainment status are not applicable requirements for
purposes of redesignation. If EPA finalizes approval of the RACM
determination, EPA has approved all part D requirements applicable
under the 1997 Annual PM2.5 NAAQS, as identified above, for
purposes of this proposed redesignation pursuant to the Sixth Circuit's
decision.
Criteria (3)--The Air Quality Improvement in the Knoxville Area Is Ddue
to Permanent and Enforceable Reductions in Emissions Resulting From
Implementation of the SIP and Applicable Federal Air Pollution Control
Regulations and Other Permanent and Enforceable Reductions
    For redesignating a nonattainment area to attainment, the CAA
requires EPA to determine that the air quality improvement in the area
is due to permanent and enforceable reductions in emissions resulting
from implementation of the SIP and applicable federal air pollution
control regulations and other permanent and enforceable reductions (CAA
section 107(d)(3)(E)(iii)). EPA has preliminarily determined that
Tennessee has demonstrated that the observed air quality improvement in
the Knoxville Area is due to permanent and enforceable reductions in
emissions resulting from federal measures and a 2011 consent decree
between Tennessee and the Tennessee Valley Authority (TVA).\18\
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    \18\ Consent Decree, State of Alabama et al. v. TVA (Civil
Action No. 3:11-cv-00170, E.D. Tenn, June 15, 2011) available in the
docket at Appendix B to Tennessee's December 20, 2016, SIP
submittal.
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    Federal measures enacted in recent years have resulted in permanent
emission reductions in particulate matter and its precursors. The
federal measures that have been implemented include:
    Tier 2 vehicle standards and low-sulfur gasoline. On February 10,
2000 (65 FR 6698), EPA promulgated Tier 2 motor vehicle emission
standards and gasoline sulfur control requirements.\19\ These emission
control requirements result in lower VOC and NOX emissions
from new cars and light duty trucks, including sport utility vehicles.
With respect to fuels, this rule required refiners and importers of
gasoline to meet lower standards for sulfur in

gasoline, which were phased in between 2004 and 2006. By 2006, refiners
were required to meet a 30 ppm average sulfur level, with a maximum cap
of 80 ppm. This reduction in fuel sulfur content ensures the
effectiveness of low emission-control technologies. The Tier 2 tailpipe
standards established in this rule were phased in for new vehicles
between 2004 and 2009. EPA estimates that, when fully implemented, this
rule will cut NOX and VOC emissions from light-duty vehicles
and light-duty trucks by approximately 76 and 28 percent, respectively.
NOX and VOC reductions from medium-duty passenger vehicles
included as part of the Tier 2 vehicle program are estimated to be
approximately 37,000 and 9,500 tons per year, respectively, when fully
implemented. In addition, EPA estimates that beginning in 2007, a
reduction of 30,000 tons per year of NOX will result from
the benefits of sulfur control on heavy-duty gasoline vehicles. Some of
these emission reductions occurred by the attainment years and
additional emission reductions will occur throughout the maintenance
period, as older vehicles are replaced with newer, compliant model
years.
---------------------------------------------------------------------------

    \19\ Tennessee also identified Tier 3 Motor Vehicle Emissions
and Fuel Standards a federal measure. EPA issued this rule on April
28, 2014 (79 FR 23414), which applies to light duty passenger cars
and trucks. EPA promulgated this rule to reduce air pollution from
new passenger cars and trucks beginning in 2017. While the
reductions did not aid the Area in attaining the standard, emissions
reductions from these standards will occur during the maintenance
period.
---------------------------------------------------------------------------

    Heavy-duty gasoline and diesel highway vehicle standards & ultra
low-sulfur diesel rule. On October 6, 2000 (65 FR 59896), EPA
promulgated a rule to reduce NOX and VOC emissions from
heavy-duty gasoline and diesel highway vehicles that began to take
effect in 2004. On January 18, 2001 (66 FR 5002), EPA promulgated a
second phase of standards and testing procedures which began in 2007 to
reduce particulate matter from heavy-duty highway engines and reduced
the maximum highway diesel fuel sulfur content from 500 ppm to 15 ppm.
The total program should achieve a 90 percent reduction in PM emissions
and a 95 percent reduction in NOX emissions for new engines
using low-sulfur diesel, compared to existing engines using higher-
content sulfur diesel. EPA expects that this rule will reduce
NOX emissions by 2.6 million tons by 2030 when the heavy-
duty vehicle fleet is completely replaced with newer heavy-duty
vehicles that comply with these emission standards.
    Non-road, large spark-ignition engines and recreational engines
standards. On November 8, 2002 (67 FR 68242), EPA adopted emission
standards for large spark-ignition engines such as those used in
forklifts and airport ground-service equipment; recreational vehicles
such as off-highway motorcycles, all-terrain vehicles, and snowmobiles;
and recreational marine diesel engines. These emission standards were
phased in from model year 2004 through 2012. When all of the non-road
spark-ignition and recreational engine standards are fully implemented,
an overall 72 percent reduction in hydrocarbons, 80 percent reduction
in NOX, and 56 percent reduction in carbon monoxide
emissions are expected by 2020. These controls help reduce ambient
concentrations of PM2.5.
    Large non-road diesel engine standards. On June 29, 2004, (69 FR
38958), EPA issued a rule adopting emissions standards for non-road
diesel engines and sulfur reductions in non-road diesel fuel. This rule
applies to diesel engines used primarily in construction, agricultural,
and industrial applications. The rule is being phased in between 2008
through 2015, and when fully implemented, will reduce emissions of
NOX, VOC, particulate matter, carbon monoxide from these
engines. It is estimated that compliance with this rule will cut
NOX emissions from non-road diesel engines by up to 90
percent nationwide.
    NOX SIP Call. On October 27, 1998 (63 FR 57356), EPA issued the
NOX SIP Call requiring the District of Columbia and 22
states to reduce emissions of NOX, a precursor to ozone and
PM2.5 pollution,and providing a mechanism (the
NOX Budget Trading Program) that states could use to achieve
those reductions. Affected states were required to comply with Phase I
of the SIP Call beginning in 2004 and Phase II beginning in 2007. By
the end of 2008, ozone season NOX emissions from sources
subject to the NOX SIP Call dropped by 62 percent from 2000
emissions levels. All NOX SIP Call states, including
Tennessee, have SIPs that currently satisfy their obligations under the
NOX SIP Call, and EPA will continue to enforce the
requirements of the NOX SIP Call.
    Reciprocating internal combustion engine National Emissions
Standards for Hazardous Air Pollutants (NESHAP). In 2010, EPA issued
rules regulating emissions of air toxics from existing compression
ignition (CI) and spark ignition (SI) stationary reciprocating internal
combustion engines (RICE) that meet specific site rating, age, and size
criteria. With these RICE standards fully implemented in 2013, EPA
estimates that the CI RICE standards reduce PM2.5 emissions
from the covered CI engines by approximately 2,800 tons per year (tpy)
and VOC emissions by approximately 27,000 tpy and that the SI RICE
standards reduce NOX emissions from the covered SI engines
by approximately 96,000 tpy.
    Boiler NESHAP. On March 21, 2011, EPA established emission
standards for industrial, commercial, and institutional boilers and
process heaters at major sources to meet hazardous air pollutant
standards reflecting the application of maximum achievable control
technology.\20\ See 76 FR 15608. The compliance dates for the rule are
January 31, 2016, for existing sources and April 1, 2013, or upon
startup, whichever is later, for new sources. New sources are defined
as sources that began operation on or after June 4, 2010. EPA estimates
that the rule will reduce nationwide emissions of VOC by approximately
2,300 tpy. See 78 FR 7138 (January 31, 2013).
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    \20\ On January 31, 2013, the EPA promulgated final amendments
to this rule. See 78 FR 7138. Following that action, the
Administrator received 13 petitions for reconsideration that
identified certain issues that petitioners claimed warranted further
opportunity for public comment. EPA took final action in response to
these petitions on November 20, 2015. See 80 FR 72790.
---------------------------------------------------------------------------

    Utility Mercury Air Toxics Standards (MATS) and New Source
Performance Standards (NSPS). The MATS for coal and oil-fired electric
generation units (EGUs) and the NSPS for fossil-fuel-fired electric
utility steam generating units were published on February 16, 2012 (77
FR 9304).\21\ The purpose is to reduce mercury and other toxic air
pollutant emissions from coal and oil-fired EGUs, 25 megawatts or more,
that generate electricity for sale and distribution through the
national electric grid to the public. The NSPS has revised emission
standards for NOX, SO2, and PM that apply to new
coal and oil-fired power plants. The MATS compliance date for existing
sources was April 16, 2015.
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    \21\ For further information, see Regulatory Impact Analysis for
Final Mercury and Air Toxics Standards, EPA-452/R-11-011/December
2011, available at https://www.epa.gov/sties/production/files/2015-11/documents/matsriafinal.pdf.
---------------------------------------------------------------------------

    CAIR and CSAPR. The Clean Air Interstate Rule (CAIR) created
regional cap-and-trade programs to reduce SO2 and
NOX emissions in 28 eastern states, including Tennessee,
that contributed to downwind nonattainment or interfered with
maintenance of the 1997 8-hour ozone NAAQS and the 1997
PM2.5 NAAQS. See 70 FR 25162 (May 12, 2005). EPA approved a
revision to Tennessee's SIP on August 20, 2007 (72 FR 46388), that
addressed the requirements of CAIR for the purpose of reducing
SO2 and NOX emissions.
    In 2008, the D.C. Circuit initially vacated CAIR, North Carolina v.
EPA, 531 F.3d 896 (D.C. Cir. 2008), but ultimately remanded the rule to
EPA without vacatur to preserve the environmental benefits provided by

CAIR, North Carolina v. EPA, 550 F.3d 1176, 1178 (D.C. Cir. 2008). On
August 8, 2011 (76 FR 48208), acting on the D.C. Circuit's remand, EPA
promulgated the Cross-State Air Pollution Rule (CSAPR) to replace CAIR
and thus to address the interstate transport of emissions contributing
to nonattainment and interfering with maintenance of the two air
quality standards covered by CAIR as well as the 2006 PM2.5
NAAQS. CSAPR requires substantial reductions of SO2 and
NOX emissions from EGUs in 28 states in the Eastern United
States. As a general matter, because CSAPR is CAIR's replacement,
emissions reductions associated with CAIR will for most areas be made
permanent and enforceable through implementation of CSAPR.
    Numerous parties filed petitions for review of CSAPR in the D.C.
Circuit, and on August 21, 2012, the Court issued its ruling, vacating
and remanding CSAPR to EPA and ordering continued implementation of
CAIR. EME Homer City Generation, L.P. v. EPA, 696 F.3d 7, 38 (D.C. Cir.
2012). The D.C. Circuit's vacatur of CSAPR was reversed by the United
States Supreme Court on April 29, 2014, and the case was remanded to
the D.C. Circuit to resolve remaining issues in accordance with the
high court's ruling. EPA v. EME Homer City Generation, L.P., 134 S. Ct.
1584 (2014). On remand, the D.C. Circuit affirmed CSAPR in most
respects, but invalidated without vacating some of the Phase 2
SO2 and NOX ozone season CSAPR budgets as to a
number of states. EME Homer City Generation, L.P. v. EPA, 795 F.3d 118
(D.C. Cir. 2015) (EME Homer City II). The CSAPR budgets for Tennessee
are not affected by the Court's decision. The litigation over CSAPR
ultimately delayed implementation of that rule for three years, from
January 1, 2012, when CSAPR's cap-and-trade programs were originally
scheduled to replace the CAIR cap-and-trade programs, to January 1,
2015. CSAPR's Phase 2 budgets were originally promulgated to begin on
January 1, 2014, and are now scheduled to begin on January 1, 2017.
CSAPR will continue to operate under the existing emissions budgets
until EPA fully addresses the D.C. Circuit's remand.\22\ Therefore, to
the extent that these transport rules impact attainment of the 1997
Annual PM2.5 NAAQS in the Knoxville Area, any emission
reductions associated with CAIR that helped the Knoxville Area achieve
attainment of the 1997 Annual PM2.5 NAAQS are permanent and
enforceable for purposes of redesignation under section
107(d)(3)(E)(iii) of the CAA because CSAPR requires similar or greater
emission reductions starting in 2015 and beyond.\23\
---------------------------------------------------------------------------

    \22\ On September 17, 2016, EPA finalized an update to the CSAPR
ozone season program. See 81 FR 74504 (October 26, 2016). The update
addresses summertime transport of ozone pollution in the eastern
United States that crosses state lines to help downwind states and
communities meet and maintain the 2008 8-hour ozone NAAQS and
addresses the remanded Phase 2 ozone season NOX budgets.
The update withdraws the remanded NOX budgets, sets new
Phase 2 CSAPR ozone season NOX emissions budgets for
eight of the eleven states with remanded budgets, and removes the
other three states from the CSAPR ozone season NOX
trading program. On November 10, 2016, EPA proposed to withdraw the
federal implementation plan provisions that require affected
electricity generating units in Texas to participate in Phase 2 of
the CSAPR trading programs for annual emissions of SO2
and NOX. See 81 FR 78954. Withdrawal of the FIP
requirements is intended to address the remand of the CSAPR Phase 2
SO2 budget for Texas. As discussed in the November 10,
2016, notice, EPA expects that EGUs in Alabama, Georgia, and South
Carolina will continue to participate in CSAPR trading programs for
SO2 and annual NOX pursuant to approved SIP
revisions (with equally or more stringent emissions budgets).
    \23\ EPA notes, however, that the Agency's air quality modeling
analysis performed as part of the CSAPR rulemaking demonstrates that
the Area would be able to maintain the 1997 Annual PM2.5
NAAQS even in the absence of either CAIR or CSAPR. See ``Air Quality
Modeling Final Rule Technical Support Document,'' App. B-62-63. This
modeling is available in the docket for this proposed redesignation
action.
---------------------------------------------------------------------------

    In addition to the above federal measures, Tennessee identified its
consent decree with TVA as providing emissions reductions that have
contributed to the improvement in air quality in the region. The
consent decree covers all of TVA's coal-fired power plants, including
two plants located in the Area (Bull Run Fossil Plant and Kingston
Fossil Plant), and among other things, requires system-wide annual
tonnage limitations for SO2 (decreasing incrementally from
285,000 tons in 2012 to 110,000 tons in 2019 and beyond); continuous
operation of existing NOX and SO2 controls\24\
and PM continuous emissions monitoring systems (CEMS) at Bull Run and
Kingston; and a maximum PM emissions rate of 0.030 pounds per million
British Thermal Units (lb/MMBtu) of heat input at Bull Run and Kingston
as of June 13, 2011, the consent decree obligation date.\25\ Emissions
data from EPA's Clean Air Markets Division (CAMD) database show that
the combined SO2 emissions from Bull Run and Kingston have
decreased by approximately 97 percent between 2008-2014 and that
combined NOX emissions have decreased by approximately 82
percent during this time period.\26\
---------------------------------------------------------------------------

    \24\ Paragraphs 69 and 85 of the Consent Decree require the
installation and continual operation of selective catalytic
reduction (SCR) and wet flue gas recirculation (Wet FGD),
respectively, for Bull Run Unit 1 and Kingston Units 1-9.
    \25\ Tennessee also notes that the consent decree requires the
repowering or retirement of units at John Sevier Fossil Plant and
Widows Creek Fossil Plant. CAMD data shows that SO2
emissions at John Sevier, located approximately 65 miles northeast
of Knoxville, decreased by approximately 100 percent between 2008-
2014 due to the retirement and replacement of the coal-fired units
with natural gas combined cycle units. The retirement of Units 1
through 6 at Widows Creek, located approximately 150 miles southwest
of Knoxville, resulted in a 49 percent decrease in SO2
emissions from 2008-2014 as these units were taken offline.
    \26\ See Section 3.1.1 of the State's submission for additional
information.
---------------------------------------------------------------------------

    Tennessee incorporated the consent decree requirements most
responsible for attaining the standard in the Area (i.e., particulate
matter emissions limit, continuous operation of NOX and
SO2 control equipment and PM CEMS, and compliance with the
system-wide annual NOX and SO2 tonnage limits)
into the Title V operating permits for Bull Run and Kingston, and the
State submitted those permit conditions to EPA for incorporation into
the SIP along with its request for redesignation.\27\ In today's
action, EPA is proposing to include these permit conditions in the SIP
as source-specific requirements.
---------------------------------------------------------------------------

    \27\ See Appendix L of the State's submission for the permit
conditions proposed for incorporation into the SIP.
---------------------------------------------------------------------------

Criteria (4)--The Knoxville Area Has a Fully-Approved Maintenance Plan
Pursuant to Section 175A of the CAA
    For redesignating a nonattainment area to attainment, the CAA
requires EPA to determine that the area has a fully approved
maintenance plan pursuant to section 175A of the CAA (CAA section
107(d)(3)(E)(iv)). In conjunction with its request to redesignate the
Knoxville Area to attainment for the 1997 Annual PM2.5
NAAQS, Tennessee submitted a SIP revision to provide for the
maintenance of the 1997 Annual PM2.5 NAAQS for at least 10
years after the effective date of redesignation to attainment. EPA
believes that this maintenance plan meets the requirements for approval
under section 175A of the CAA for the reasons discussed below.
a. What is required in a maintenance plan?
    Section 175A of the CAA sets forth the elements of a maintenance
plan for areas seeking redesignation from nonattainment to attainment.
Under section 175A, the plan must demonstrate continued attainment of
the applicable NAAQS for at least 10 years after the Administrator
approves a redesignation to attainment. Because the 1997 primary Annual
PM2.5 NAAQS

will be revoked for the Area if the Area is redesignated to attainment,
Tennessee is not required to submit a second 10-year maintenance plan
for the 1997 primary Annual PM2.5 NAAQS. See 81 FR 58010,
58144. To address the possibility of future NAAQS violations, the
maintenance plan must contain such contingency measures, as EPA deems
necessary, to assure prompt correction of any future 1997 Annual
PM2.5 NAAQS violations. The Calcagni Memorandum provides
further guidance on the content of a maintenance plan, explaining that
a maintenance plan should address five requirements: The attainment
emissions inventory, maintenance demonstration, monitoring,
verification of continued attainment, and a contingency plan. As is
discussed below, EPA finds that Tennessee's maintenance plan includes
all the necessary components and is thus proposing to approve it as a
revision to the Tennessee SIP.
b. Attainment Emissions Inventory
    As discussed above, EPA is proposing to determine that the
Knoxville Area is attaining the 1997 PM2.5 NAAQS based on a
monitoring data for the 3-year period from 2013-2015. In its
maintenance plan, Tennessee selected 2014 as the attainment emission
inventory year. The attainment inventory identifies the level of
emissions in the Area that is sufficient to attain the 1997 Annual
PM2.5 NAAQS. Tennessee began development of the attainment
inventory by first generating a baseline emissions inventory for the
Area. As noted above, Tennessee selected 2002 as the base year for
developing a comprehensive emissions inventory. The projected inventory
included with the maintenance plan estimates emissions from 2014 to
2028, which satisfies the 10-year interval required in section 175(A)
of the CAA.
    The emissions inventories are composed of four major types of
sources: Point, area, on-road mobile, and non-road mobile. The
attainment and future year emissions inventories were developed/
projected as follows:
     Point source emissions were obtained from the 2014
National Emissions Inventory (NEI) and projected inventories were
calculated using growth factors derived from the 2015 Annual Energy
Outlook (AEO2015) developed by the U.S. Energy Information
Administration. Growth factors were developed for point sources based
on North American Industry Classification System codes and/or Source
Classification Codes.
     Area source emissions were developed using EPA Nonpoint
files located on EPA's CHIEF Emission Inventory Web site for the 2014
NEI and projected inventories by using 2014 emissions and growth
factors obtained from Annual Energy Outlook 2015 energy forecasts for
consumption and production, and TranSystems Category Specific Growth
Factors.
     On-road mobile emissions were estimated using the latest
version of EPA's MOVES2014a model. The input parameters for the model
runs were developed, reviewed and agreed to by the transportation
partners through interagency consultation.\28\ Attainment year (2014)
vehicle miles traveled (VMT) data was obtained from the Tennessee
Department of Transportation through the HPMS (Highway Performance
Monitoring System) system. Future VMT estimates were provided by the
Knoxville Regional Transportation Planning Organization based on travel
demand modeling performed for the nonattainment counties. For all
interim years between the years 2014 and 2028, onroad emissions were
interpolated.
---------------------------------------------------------------------------

    \28\ The interagency consultation partners consist of the
following entities: EPA, the United States Department of
Transportation (Federal Highway Administration and Federal Transit
Administration), the Knoxville Regional Transportation Planning
Organization, Knox County Department of Air Quality management, the
Tennessee Department of Transportation, the Lakeway Area
Metropolitan Planning Organization, the Great Smokey Mountains
National Park Service and the Tennessee Department of Environment
and Conservation.
---------------------------------------------------------------------------

     Non-road mobile emissions were obtained from EPA's Nonroad
files located on EPA's EIS Gateway for the 2011 NEI and using
MOVES2014a. Future nonroad mobile emissions were projected using 2011
emissions and national growth factors. Growth factors were multiplied
by the 2014 emission values to calculate emissions for future years.
    The 2014 SO2, NOX, PM2.5, VOC, and
ammonia missions for the Knoxville Area are summarized in Tables 2
through 6.
    Section 175A requires a state seeking redesignation to attainment
to submit a SIP revision to provide for the maintenance of the NAAQS in
the Area ``for at least 10 years after the redesignation.'' EPA has
interpreted this as a showing of maintenance ``for a period of ten
years following redesignation.'' Calcagni Memorandum, p. 9. Where the
emissions inventory method of showing maintenance is used, the purpose
is to show that emissions during the maintenance period will not
increase over the attainment year inventory. Calcagni Memorandum, pp.
9-10.
    As discussed in detail below, Tennessee's maintenance plan
submission expressly documents that the Area's overall emissions
inventories will remain below the attainment year inventories through
2028. In addition, for the reasons set forth below, EPA believes that
the Area will continue to maintain the 1997 Annual PM2.5
NAAQS through 2028. Thus, if EPA finalizes its proposed approval of the
redesignation request and maintenance plan, the approval will be based
upon this showing, in accordance with section 175A, and EPA's analysis
described herein, that Tennessee's maintenance plan provides for
maintenance for at least ten years after redesignation.
c. Maintenance Demonstration
    The maintenance plan for the Knoxville Area includes a maintenance
demonstration that:
    (i) Shows compliance with and maintenance of the Annual
PM2.5 standard by providing information to support the
demonstration that current and future emissions of SO2,
NOX, PM2.5, and VOCs remain at or below 2014
emissions levels.
    (ii) Uses 2014 as the attainment year and includes future emission
inventory projections for 2028.
    (iii) Identifies an ``out year'' at least 10 years after EPA review
and potential approval of the maintenance plan. Per 40 CFR part 93,
NOX and PM2.5 MVEBs were established for the last
year (2028) of the maintenance plan. Additionally, Tennessee chose,
through interagency consultation, to establish NOx and PM2.5
MVEBs for 2014 (see section VI below).
    (iv) Provides, as shown in Tables 2 through 6 below, the estimated
and projected emissions inventories, in tpy, for the Knoxville Area,
for PM2.5, NOX, SO2, VOC, and ammonia.

                                Table 2--Knoxville Area PM2.5 Emission Inventory
                                                      [tpy]
----------------------------------------------------------------------------------------------------------------
                                       Point           Area           Onroad          Nonroad          Total
----------------------------------------------------------------------------------------------------------------
2014............................        1,129.70        1,772.14          444.78          194.60        3,541.21
2017............................        1,081.26        1,804.53          384.89          169.64        3,440.31
2020............................        1,165.20        1,856.91          324.99          152.38        3,499.48
2023............................        1,184.98        1,913.79          265.10          144.52        3,508.39
2026............................        1,205.31        1,966.42          205.21          143.46        3,520.40
2028............................        1,211.30        2,005.01          165.28          149.23        3,530.82
----------------------------------------------------------------------------------------------------------------

                                 Table 3--Knoxville Area NOX Emission Inventory
                                                      [tpy]
----------------------------------------------------------------------------------------------------------------
                                       Point           Area           Onroad          Nonroad          Total
----------------------------------------------------------------------------------------------------------------
2014............................        6,041.52        1,126.29       15,597.73        2,789.33       25,554.88
2017............................        5,725.54          985.98       13,232.05        2,567.57       22,511.14
2020............................        6,134.99          982.48       10,866.37        2,490.86       20,474.69
2023............................        6,217.20          977.19        8,500.68        2,560.11       18,255.18
2026............................        6,303.95          976.34        6,135.00        2,791.12       16,206.41
2028............................        6,336.33          977.04        4,557.88        3,230.56       15,101.81
----------------------------------------------------------------------------------------------------------------

                                 Table 4--Knoxville Area SO2 Emission Inventory
                                                      [tpy]
----------------------------------------------------------------------------------------------------------------
                                       Point           Area           Onroad          Nonroad          Total
----------------------------------------------------------------------------------------------------------------
2014............................        4,146.99           30.10           83.39           47.17        4,307.65
2017............................        3,125.61           35.25           73.20           58.23        3,292.29
2020............................        3,420.16           36.67           63.02           77.81        3,597.65
2023............................        3,454.73           37.40           52.84          107.89        3,652.86
2026............................        3,499.37           37.93           42.65          153.67        3,733.63
2028............................        3,514.63           37.98           35.86          222.93        3,811.40
----------------------------------------------------------------------------------------------------------------

                                 Table 5--Knoxville Area VOCs Emission Inventory
                                                      [tpy]
----------------------------------------------------------------------------------------------------------------
                                       Point           Area           Onroad          Nonroad          Total
----------------------------------------------------------------------------------------------------------------
2014............................        2,944.28        8,869.86        6,122.57        2,340.70       20,277.41
2017............................        3,454.23        8,889.45        5,321.37        2,001.12       19,666.17
2020............................        3,814.52        9,000.92        4,520.18        1,794.24       19,129.86
2023............................        4,039.05        9,116.64        3,718.99        1,741.57       18,616.23
2026............................        4,251.65        9,239.75        2,917.79        1,766.53       18,175.73
2028............................        4,380.02        9,309.98        2,383.66        1,863.80       17,937.46
----------------------------------------------------------------------------------------------------------------

                               Table 6--Knoxville Area Ammonia Emission Inventory
                                                      [tpy]
----------------------------------------------------------------------------------------------------------------
                                       Point           Area           Onroad          Nonroad          Total
----------------------------------------------------------------------------------------------------------------
2014............................           90.58        1,113.99          305.40            2.77        1,512.74
2017............................           88.83        1,166.32          296.59            2.82        1,554.57
2020............................           91.19        1,205.32          287.78            2.89        1,587.18
2023............................           92.69        1,234.43          278.97            2.96        1,609.05
2026............................           93.37        1,244.01          270.16            3.04        1,610.57
2028............................           93.56        1,253.67          264.29            3.09        1,614.61
----------------------------------------------------------------------------------------------------------------

    In situations where local emissions are the primary contributor to
nonattainment, such as the Knoxville Area, if the future projected
emissions in the nonattainment area remain at or below the baseline
emissions in the nonattainment area, then the ambient air quality
standard should not be exceeded in the future. As reflected above in
Tables 2 through 5, future emissions of PM2.5,
NOX, SO2, and VOC in the Knoxville Area are
expected to be below the ``attainment level'' emissions in 2014, thus
illustrating that the Knoxville Area is expected to continue to attain
the 1997 PM2.5 NAAQS through 2028 and beyond. Emissions of
direct PM2.5, NOX, SO2, and VOCs in
the Knoxville Area are expected to decrease from 2014 to 2028 by
approximately 1 percent, 41 percent, 12 percent, and 22

percent, respectively. Although ammonia emissions are projected to
increase between 2014 and 2028, the emissions increase is relatively
small (approximately 102 tpy), total ammonia emissions are already
relatively low (approximately 1,513 tpd in 2014), there are no major
stationary sources of ammonia in the Area, the Area is well below the
NAAQS, and the decrease in emissions of the other precursors more than
offset the projected increase. Thus, the projected inventories indicate
that future emissions in the Knoxville Area are expected to support
continued maintenance of the 1997 Annual PM2.5 NAAQS through
2028.
    As discussed in section VI of this proposed rulemaking, a safety
margin is the difference between the attainment level of emissions
(from all sources) and the projected level of emissions (from all
sources) in the maintenance plan. The attainment level of emissions is
the level of emissions during one of the years in which the Area met
the NAAQS. Tennessee selected 2014 as the attainment emissions
inventory year for the Knoxville Area. Tennessee calculated a safety
margin in its submittal for the year 2028 and allocated the entire
portion of the 2028 PM2.5 safety margin in tons per day
(tpd) to the 2028 MVEB for the Knoxville Area. Specifically, 10.39 tpy
of the safety margin is allocated to the 2028 PM2.5 MVEB.
Also, Tennessee allocated 2,613.27 tpy of the 2028 NOX
safety margin to the 2028 NOX MVEB. The allocation and the
resulting available safety margins for the Knoxville Area are discussed
further in section VI of this proposed rulemaking.
d. Monitoring Network
    There are currently seven monitors measuring PM2.5 in
the Knoxville Area. Tennessee, through TDEC, has committed to continue
operation of the monitors in the Knoxville Area in compliance with 40
CFR part 58 and have thus addressed the requirement for monitoring. EPA
approved Tennessee's 2016 monitoring plan on October 21, 2016.
e. Verification of Continued Attainment
    Tennessee, through TDEC, has the legal authority to enforce and
implement the requirements of the Knoxville Area 1997 Annual
PM2.5 maintenance plan. This includes the authority to
adopt, implement, and enforce any subsequent emissions control
contingency measures determined to be necessary to correct future
PM2.5 attainment problems.
    TDEC will track the progress of the maintenance plan by performing
future reviews of triennial emission inventories for the Knoxville Area
as required in the Air Emissions Reporting Rule (AERR). Emissions
information will be compared to the 2014 attainment year to assure
continued compliance with the annual PM2.5 standard.
f. Contingency Measures in the Maintenance Plan
    Section 175A of the CAA requires that a maintenance plan include
such contingency measures as EPA deems necessary to assure that a state
will promptly correct a violation of the NAAQS that occurs after
redesignation. The maintenance plan should identify the contingency
measures to be adopted, a schedule and procedure for adoption and
implementation, and a time limit for action by Tennessee. A state
should also identify specific indicators to be used to determine when
the contingency measures need to be implemented. The maintenance plan
must include a requirement that a state will implement all measures
with respect to control of the pollutant that were contained in the SIP
before redesignation of the area to attainment in accordance with
section 175A(d).
    The contingency plan included in the submittal contains a
commitment to implement measures that exist in the current SIP for
PM2.5 and identifies triggers to determine when contingency
measures are needed and a process of developing and implementing
appropriate control measures. The primary trigger of the contingency
plan is a quality assured/quality controlled violating design value of
the 1997 Annual PM2.5 NAAQS at any monitor. Upon activation
of the primary trigger, Tennessee, in conjunction with the Knox County
Department of Air Quality Management (DAQM), will commence an analysis
to determine what additional measures will be necessary to attain or
maintain the 1997 Annual PM2.5 NAAQS. In the event of a
monitored violation of the 1997 Annual PM2.5 NAAQS in the
Area, Tennessee commits to adopt and implement one or more of the
following control measures within 24 months of the monitored violation
in order to bring the Area into compliance:
     Additional RACT for point sources of PM2.5
emissions not already covered by RACT, best available control
technology (BACT), or reasonable and proper emission limitations;
     Additional RACM for area sources of PM2.5;
     Additional RACT for major point sources of NOX
emissions;
     Additional RACT for minor point sources of NOX
emissions;
     Additional RACM for area sources of NOX
emissions;
     Additional RACT for major point sources of SO2
emissions;
     Additional RACT for minor point sources of SO2
emissions;
     Additional RACM for area sources of SO2
emissions; and
     Other control measures, not included in the above list, if
new control programs are deemed more advantageous for the Area.
    A secondary trigger is activated when one of the following
conditions occurs that may forewarn of a potential exceedance of the
Annual PM2.5 NAAQS:
     An annual mean PM2.5 concentration (average of
quarterly-average concentrations) of greater than or equal to 16.0
[mu]g/m\3\ for the previous calendar year at any federal reference
monitor (FRM) in the Area, based on quality-assured and certified
monitoring data;
     An annual mean PM2.5 concentration (average of
quarterly-average concentrations) of greater than or equal to 15.5
[mu]g/m\3\ for each of the previous two calendar years at any federal
reference monitor (FRM) in the Area, based on quality-assured and
certified monitoring data;
     Total emissions of PM2.5, SO2, or
NOX in the most recent NEI for the Area exceeding 130
percent of the corresponding emissions for 2014 for that pollutant.

If the secondary trigger is activated, Tennessee and Knox County DAQM
will investigate the occurrence and evaluate existing control measures
to determine whether further emission reduction measures should be
implemented.
    EPA preliminarily concludes that the maintenance plan adequately
addresses the five basic components of a maintenance plan: attainment
emission inventory, maintenance demonstration, monitoring network,
verification of continued attainment, and a contingency plan.
Therefore, EPA proposes to find that the maintenance plan SIP revision
submitted by Tennessee for Knoxville Area meets the requirements of
section 175A of the CAA and is approvable.

VI. What is EPA's analysis of the proposed NOX and
PM2.5 MVEBs for the Knoxville?

    Under section 176(c) of the CAA, new transportation plans,
programs, and projects, such as the construction of new highways, must
``conform'' to (i.e., be consistent with) the part of a state's air
quality plan that addresses pollution from cars and trucks. Conformity
to the

SIP means that transportation activities will not cause new air quality
violations, worsen existing violations, or delay timely attainment of
the NAAQS or any interim milestones. If a transportation plan does not
conform, most new projects that would expand the capacity of roadways
cannot go forward. Regulations at 40 CFR part 93 set forth EPA policy,
criteria, and procedures for demonstrating and assuring conformity of
such transportation activities to a SIP. The regional emissions
analysis is one, but not the only, requirement for implementing
transportation conformity. Transportation conformity is a requirement
for nonattainment and maintenance areas. Maintenance areas are areas
that were previously nonattainment for a particular NAAQS but have
since been redesignated to attainment with an approved maintenance plan
for that NAAQS.
    Under the CAA, states are required to submit, at various times,
control strategy SIPs and maintenance plans for nonattainment areas.
These control strategy SIPs (including RFP and attainment
demonstration) and maintenance plans create MVEBs for criteria
pollutants and/or their precursors to address pollution from cars and
trucks. Per 40 CFR part 93, a MVEB must be established for the last
year of the maintenance plan. A state may adopt MVEBs for other years
as well. The MVEB is the portion of the total allowable emissions in
the maintenance demonstration that is allocated to highway and transit
vehicle use and emissions. See 40 CFR 93.101. The MVEB serves as a
ceiling on emissions from an area's planned transportation system. The
MVEB concept is further explained in the preamble to the November 24,
1993, Transportation Conformity Rule (58 FR 62188). The preamble also
describes how to establish the MVEB in the SIP and how to revise the
MVEB.
    After interagency consultation with the transportation partners for
the Knoxville Area, Tennessee has elected to develop MVEBs for
NOX and PM2.5 for the entire Area. MVEBs were not
developed for VOCs and ammonia because these pollutants are not
significant contributors to mobile source emissions in the Knoxville
Area. Tennessee developed these MVEBs, as required, for the last year
of its maintenance plan, 2028. Tennessee also established MVEBs for the
attainment year of 2014. The MVEBs reflect the total on-road emissions
for 2014 and 2028, plus an allocation from the available NOX
and PM2.5 safety margin. Under 40 CFR 93.101, the term
``safety margin'' is the difference between the attainment level (from
all sources) and the projected level of emissions (from all sources) in
the maintenance plan. The safety margin can be allocated to the
transportation sector; however, the total emissions must remain below
the attainment level. The NOX and PM2.5 MVEBs and
allocation from the safety margin were developed in consultation with
the transportation partners and were added to account for uncertainties
in population growth, changes in model vehicle miles traveled, and new
emission factor models. Further details are provided below to explain
how the PM2.5 MVEBs for 2028 were derived.
    The State developed the worst case scenario to estimate the
potential emissions increases due to changes in the models and planning
assumptions mentioned earlier. For the worst case scenario, an analysis
year of 2045 was selected. In addition, projected VMT was increased by
10 percent, the age of the vehicle fleet was increased by approximately
two years, and the vehicle source type population was increased by 10
percent above the projected vehicle source type population for 2045.
This analysis yielded emissions of PM2.5 from on-road
sources of about 80 tpy above those projected from on-road sources in
2028. Since the entire PM2.5 safety margin of 10.39 tpy is
allocated to the 2028 MVEB, an additional 69.33 tpy is still needed to
cover the emissions increases modeled in the worst case scenario.
    Since there is no apparent PM2.5 safety margin remaining
to allocate the additional 69.33 tpy to the 2028 MVEB, Tennessee
performed a speciation data assessment to analyze the relationship
between PM2.5 emissions and ambient concentrations and the
impact it has on the future air quality in the Knoxville Area with the
additional allocation to the 2028 MVEB. With the additional 69.33 tpy
allocation, the overall PM2.5 emissions from the base year
2014 increases from 3,541 tpy to 3,610 tpy in the out year of 2028.
This is equal to approximately a 2 percent increase in attainment year
PM2.5 emissions. Tennessee's analysis indicates that a 2
percent direct PM2.5 increase will cause a 2 percent
increase in ambient concentrations of PM2.5 which equates to
0.19 [micro]g/m\3\.
    As mentioned in Section V, the three-year design value for years
2013-2015 is 10.0 [micro]g/m\3\. Therefore, the design value would be
10.19 [micro]g/m\3\ with the 2 percent increase. Even with the 2
percent increase in ambient PM2.5 concentrations, the 10.19
[micro]g/m\3\ design value is still below the 1997 Annual
PM2.5 NAAQS of 15 [micro]g/m\3\ and the 2012 Annual
PM2.5 NAAQS of 12.0 [micro]g/m\3\.\29\ Furthermore, the on-
road PM2.5 emissions as compared to the overall
PM2.5 emissions from all sectors trend downward from 12.6
percent in 2014 to 4.7 percent in 2028. See Table 7, below.
---------------------------------------------------------------------------

    \29\ Tennessee describes the speciation analysis in Section 4 of
the submittal. See Figure 4.1 for more details.

    Table 7--PM2.5 On-Road Mobile Emissions Comparison to the Total PM2.5 Emissions From All Sectors for the
                                                 Knoxville Area
                                                 [Tons per day]
----------------------------------------------------------------------------------------------------------------
                                        2014         2017         2020         2023         2026         2028
----------------------------------------------------------------------------------------------------------------
PM2.5 On-road emissions...........       444.78       384.89       324.99       265.10       205.21       165.28
Total PM2.5 emissions (all             3,541.21      3440.31      3499.48      3508.39      3520.40     3,530.82
 sectors).........................
On-road % of total PM2.5 emissions         12.6         11.1          9.3          7.6          5.8          4.7
----------------------------------------------------------------------------------------------------------------

Therefore, based on the Tennessee's speciation data assessment which
concludes that there is a decrease in sulfate and nitrate
concentrations even with a projected 2 percent increase in direct
PM2.5 emissions coupled with the downward trend in on-road
emissions, the Knoxville Area is expected to maintain the 1997 Annual
PM2.5 standard.
    The interagency consultation group approved a 10.39 tpy safety
margin for

direct PM2.5 mobile source emission estimates for the year
2028 and 2,613.27 tpy safety margin for NOX mobile source
emission estimates for the year 2028. The NOX and
PM2.5 MVEBs for the Knoxville Area are defined in Table 8,
below.

         Table 8--MVEB With Safety Margin for the Knoxville Area
                                  [tpy]
------------------------------------------------------------------------
                Pollutant                      2014            2028
------------------------------------------------------------------------
PM2.5 On-road Emissions.................          444.78          165.28
Safety Margin allocation................  ..............         * 79.72
                                         -------------------------------
    PM2.5 MVEB..........................          444.78          245.00
NOX On-road Emissions...................       15,597.73        4,557.88
Safety Margin allocation................  ..............        2,613.27
                                         -------------------------------
    NOX MVEB............................       15,597.73        7,171.14
------------------------------------------------------------------------
* The MVEB for PM2.5 in 2028 includes the available safety margin of
  10.39 tons/year and an additional 69.33 tons/year.

    There is no safety margin remaining for PM2.5, and the
remaining safety margin for NOX is 7,839.80 tpy. Through
this rulemaking, EPA is proposing to approve into the Tennessee SIP the
MVEBs for NOX and PM2.5 for 2014 and
2028 for the Knoxville Area because EPA has determined that the Area
maintains the 1997 Annual PM2.5 NAAQS with the emissions at
the levels of the budgets. The MVEBs for the Knoxville Area were found
adequate and are being used to determine transportation conformity.
After thorough review, EPA is proposing to approve the budgets because
they are consistent with maintenance of the 1997 Annual
PM2.5 NAAQS through 2028. If the proposed redesignation is
finalized, the Area will no longer be subject to transportation or
general conformity requirements for the 1997 Annual PM2.5
NAAQS upon the effective date of the redesignation because the
redesignation will revoke the 1997 primary Annual PM2.5
NAAQS for the Area. However, in the meantime, the applicable budgets
for required regional emissions analysis years between the present time
and 2028 are the new 2014 MVEBs; and the applicable budgets for years
2028 and beyond will be the new 2028 MVEBs. EPA notes that the Agency
has already determined that these budgets are adequate for
transportation conformity purposes.

VII. What is the effect of EPA's proposed actions?

    EPA's proposed actions establish the basis upon which EPA may take
final action on the issues being proposed for approval. Approval of
Tennessee's redesignation request would change the legal designation of
Anderson, Blount, Knox, and Loudon Counties and a portion of Roane
County for the 1997 Annual PM2.5 NAAQS, found at 40 CFR part
81, from nonattainment to attainment. Approval of Tennessee's
associated SIP revision would also incorporate a plan for maintaining
the 1997 Annual PM2.5 NAAQS in the Area through 2028,
Tennessee's RACM determination, and source-specific requirements for
two sources in the Area into the Tennessee SIP. The maintenance plan
includes contingency measures to remedy any future violations of the
1997 Annual PM2.5 NAAQS and procedures for evaluation of
potential violations. The maintenance plan also includes NOX
and PM2.5 MVEBs for the Knoxville Area.

VIII. Proposed Actions

    EPA is proposing to: (1) Approve Tennessee's RACM determination for
the Knoxville Area pursuant to CAA sections 172(c)(1) and 189(a)(1)(C)
and incorporate it into the SIP; (2) determine that the Area is
attaining the 1997 Annual PM2.5 NAAQS based on 2013-2015
data; (3) approve Tennessee's plan for maintaining the 1997 Annual
PM2.5 NAAQS (maintenance plan), including the associated
MVEBs for the Knoxville Area, and incorporate it into the Tennessee
SIP; (4) to incorporate source-specific requirements for two sources in
the Area into the SIP; and (5) redesignate the Knoxville Area to
attainment for the 1997 Annual PM2.5 NAAQS.
    If finalized, approval of the redesignation request would change
the official designation of Anderson, Blount, Knox and Loudon Counties
and a portion of Roane County for the 1997 Annual PM2.5
NAAQS, found at 40 CFR part 81 from nonattainment to attainment, as
found at 40 CFR part 81.

IX. Statutory and Executive Order Reviews

    Under the CAA, redesignation of an area to attainment and the
accompanying approval of a maintenance plan under section 107(d)(3)(E)
are actions that affect the status of a geographical area and do not
impose any additional regulatory requirements on sources beyond those
imposed by state law. A redesignation to attainment does not in and of
itself create any new requirements, but rather results in the
applicability of requirements contained in the CAA for areas that have
been redesignated to attainment. Moreover, the Administrator is
required to approve a SIP submission that complies with the provisions
of the Act and applicable Federal regulations. See 42 U.S.C. 7410(k);
40 CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to
approve state choices, provided that they meet the criteria of the CAA.
Accordingly, these proposed actions merely approve Commonwealth law as
meeting federal requirements and do 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 Order 12866 (58
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January, 21, 2011);
     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 application of those requirements would be inconsistent
with the CAA; and
     will not have disproportionate human health or
environmental effects under Executive Order 12898 (59 FR 7629, February
16, 1994).
    In addition, the SIP is 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 of tribal governments or preempt tribal
law.

List of Subjects

40 CFR Part 52

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

 40 CFR Part 81

    Environmental protection, Air pollution control.

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

    Dated: April 27, 2017.
V. Anne Heard,
Acting Regional Administrator, Region 4.
[FR Doc. 2017-10914 Filed 5-26-17; 8:45 am]
 BILLING CODE 6560-50-P