[Federal Register: October 7, 2010 (Volume 75, Number 194)]
[Proposed Rules]
[Page 62026-62040]
[DOCID:fr07oc10-21]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R04-OAR-2010-0666-201031; FRL-9211-3]

Approval and Promulgation of Implementation Plans and Designation
of Areas for Air Quality Planning Purposes; Tennessee; Redesignation of
the Knoxville 8-Hour Ozone Nonattainment Area to Attainment for Ozone

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: On July 14, 2010, the State of Tennessee, through the
Tennessee

Department of Environment and Conservation (TDEC), Air Pollution
Control Division, submitted a request to redesignate the Knoxville 8-
hour ozone nonattainment area to attainment for the 1997 8-hour
National Ambient Air Quality Standards (NAAQS); and to approve a State
Implementation Plan (SIP) revision containing a maintenance plan for
the Knoxville, Tennessee Area. The Knoxville 1997 8-hour ozone
nonattainment area is comprised of Anderson, Blount, Jefferson, Knox,
Loudon, and Sevier Counties in their entireties, and the portion of
Cocke County that falls within the boundary of the Great Smoky
Mountains National Park (hereafter referred to as the ``Knoxville
Area''). In this action, EPA is proposing to approve the July 14, 2010,
8-hour ozone redesignation request for the Knoxville Area.
Additionally, EPA is proposing to approve the 1997 8-hour ozone NAAQS
maintenance plan for the Knoxville Area, including the 2007 baseline
emission inventory, and the motor vehicle emission budgets (MVEBs) for
nitrogen oxides (NOX) and volatile organic compounds (VOC)
for 2024 for the Knoxville Area. This proposed approval of Tennessee's
redesignation request is based on EPA's determination that the
Knoxville Area has met the criteria for redesignation to attainment
specified in the Clean Air Act (CAA), including the determination that
the Knoxville 8-hour ozone nonattainment area has attained the 1997 8-
hour ozone NAAQS. In this action, EPA is also describing the status of
its transportation conformity adequacy determination for the new 2024
MVEBs that are contained in the 1997 8-hour ozone NAAQS maintenance
plan for the Knoxville Area. This action is being taken pursuant to the
CAA and its implementing regulations.

DATES: Comments must be received on or before November 8, 2010.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2010-0666, by one of the following methods:
    1. http://www.regulations.gov: Follow the on-line instructions for
submitting comments.
    2. E-mail<EMAIL_ADDRESS>    3. Fax:<PHONE_NUMBER>.
    4. Mail: EPA-R04-OAR-2010-0666, Regulatory Development Section, Air
Planning Branch, Air, Pesticides and Toxics Management Division, U.S.
Environmental Protection Agency, Region 4, 61 Forsyth Street, SW.,
Atlanta, Georgia 30303-8960.
    5. Hand Delivery or Courier: Ms. Lynorae Benjamin, Chief,
Regulatory Development Section, Air Planning Branch, Air, Pesticides
and Toxics Management Division, U.S. Environmental Protection Agency,
Region 4, 61 Forsyth Street, SW., Atlanta, Georgia 30303-8960. Such
deliveries are only accepted during the Regional Office's normal hours
of operation. The Regional Office's official hours of business are
Monday through Friday, 8:30 a.m. to 4:30 p.m., excluding Federal
holidays.
    Instructions: Direct your comments to Docket ID No. EPA-R04-OAR-
2010-0666. EPA's policy is that all comments received will be included
in the public docket without change and may be made available online at
http://www.regulations.gov, including any personal information
provided, unless the comment includes information claimed to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Do not submit through http://
www.regulations.gov or e-mail, information that you consider to be CBI
or otherwise protected. The http://www.regulations.gov Web site is an
``anonymous access'' system, which means EPA will not know your
identity or contact information unless you provide it in the body of
your comment. If you send an e-mail comment directly to EPA without
going through http://www.regulations.gov, your e-mail address will be
automatically captured and included as part of the comment that is
placed in the public docket and made available on the Internet. If you
submit an electronic comment, EPA recommends that you include your name
and other contact information in the body of your comment and with any
disk or CD-ROM you submit. If EPA cannot read your comment due to
technical difficulties and cannot contact you for clarification, EPA
may not be able to consider your comment. Electronic files should avoid
the use of special characters, any form of encryption, and be free of
any defects or viruses. For additional information about EPA's public
docket visit the EPA Docket Center homepage at http://www.epa.gov/
epahome/dockets.htm.
    Docket: All documents in the electronic docket are listed in the
http://www.regulations.gov index. Although listed in the index, some
information is not publicly available, i.e., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, is not placed on the Internet and will be
publicly available only in hard copy form. Publicly available docket
materials are available either electronically in http://
www.regulations.gov or in hard copy at the Regulatory Development
Section, Air Planning Branch, Air, Pesticides and Toxics Management
Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth
Street, SW., Atlanta, Georgia 30303-8960. EPA requests that if at all
possible, you contact the person listed in the FOR FURTHER INFORMATION
CONTACT section to schedule your inspection. The Regional Office's
official hours of business are Monday through Friday, 8:30 a.m. to 4:30
p.m., excluding Federal holidays.

FOR FURTHER INFORMATION CONTACT: Jane Spann or Royce Dansby-Sparks of
the Regulatory Development Section, in the Air Planning Branch, Air,
Pesticides and Toxics Management Division, U.S. Environmental
Protection Agency, Region 4, 61 Forsyth Street, SW., Atlanta, Georgia
30303-8960. Ms. Spann may be reached by phone at<PHONE_NUMBER>, or via
electronic mail at<EMAIL_ADDRESS>Mr. Dansby-Sparks may be reached
by phone at<PHONE_NUMBER>, or via electronic mail at dansby-
<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Table of Contents

I. What proposed actions is EPA taking?
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 the effect of EPA's proposed actions?
VI. What is EPA's analysis of the request?
VII. What is EPA's analysis of Tennessee's proposed NOX
and VOC MVEBs for the Knoxville area?
VIII. What is the status of EPA's adequacy determination for the
proposed NOX and VOC MVEBs for 2024 for the Knoxville
area?
IX. What is EPA's analysis of the proposed 2007 base year emissions
inventory for the Knoxville Area?
X. Proposed Action on the Redesignation Request and Maintenance Plan
SIP Revision Including Proposed Approval of the 2024 NOX
and VOC MVEBs for the Knoxville Area
XI. Statutory and Executive Order Reviews

I. What proposed actions is EPA taking?

    EPA is proposing several related actions, which are summarized
below and described in greater detail throughout this notice of
rulemaking: (1) To redesignate the Knoxville Area to attainment for the
1997 8-hour ozone NAAQS; (2) to approve under section 172(c)(3) the
emissions inventory submitted with the maintenance plan; and (3) to
approve, under section 175A of the CAA, Knoxville's 1997 8-hour ozone
NAAQS maintenance plan into the Tennessee SIP, including the associated
MVEBs. In addition, and

related to today's actions, EPA is also notifying the public of the
status of EPA's adequacy determination for the Knoxville Area MVEBs.
    First, EPA is proposing to determine that the Knoxville Area has
attained the 1997 8-hour ozone NAAQS. EPA further proposes to determine
that, if EPA's proposed approval of the 2007 baseline emissions
inventory for the Knoxville Area is finalized, the Area has met the
requirements for redesignation under section 107(d)(3)(E) of the CAA.
The Knoxville Area 1997 8-hour ozone area is composed of Anderson,
Blount, Jefferson, Knox, Loudon, and Sevier Counties in their
entireties, and the portion of Cocke County that falls within the
boundary of the Great Smoky Mountains National Park. In this action,
EPA is now proposing to approve a request to change the legal
designation of Anderson, Blount, Jefferson, Knox, Loudon, and Sevier
Counties in their entireties, and the portion of Cocke County that
falls within the boundary of the Great Smoky Mountains National Park in
the Knoxville Area from nonattainment to attainment for the 1997 8-hour
ozone NAAQS.
    Second, EPA is proposing to approve under the CAA, Tennessee's 2007
inventory for the Knoxville Area (under section 172(c)(3)). Tennessee
selected 2007 as the attainment emissions inventory year for the
Knoxville Area. This attainment inventory identifies the level of
emissions in the Area, which is sufficient to attain the 1997 8-hour
ozone NAAQS.
    Third, EPA is proposing to approve Tennessee's 1997 8-hour ozone
NAAQS maintenance plan for the Knoxville Area (such approval being one
of the CAA criteria for redesignation to attainment status). The
maintenance plan is designed to help keep the Knoxville Area in
attainment of the 1997 8-hour ozone NAAQS through 2024. Consistent with
the CAA, the maintenance plan that EPA is proposing to approve today
also includes 2024 NOX and VOC MVEBs. EPA is proposing to
approve (into the Tennessee SIP) the 2024 MVEBs that are included as
part of Tennessee's maintenance plan for the 1997 8-hour ozone NAAQS.
    EPA is also notifying the public of the status of EPA's adequacy
process for the newly-established 2024 NOX and VOC MVEBs for
the Knoxville Area. The Adequacy comment period for the Knoxville Area
2024 MVEBs began on June 15, 2010, with EPA's posting of the
availability of this submittal on EPA's Adequacy Web site. (http://
www.epa.gov/otaq/stateresources/transconf/currsips.htm). The Adequacy
comment period for these MVEBs closed on July 15, 2010. No adverse
comments were received during the Adequacy public comment period. On
September 15, 2010, EPA published its adequacy notice for the 2024
MVEB's for the Knoxville Area (75 FR 55977). Please see section VIII of
this proposed rulemaking for further explanation of this process, and
for more details on the MVEBs determination.
    Today's notice of proposed rulemaking is in response to Tennessee's
July 14, 2010, SIP submittal requesting the redesignation of the
Knoxville 1997 8-hour ozone area, and includes a SIP revision
addressing the specific issues summarized above and the necessary
elements for redesignation described in section 107(d)(3)(E) of the
CAA.

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

    The CAA establishes a process for air quality management through
the NAAQS. Ozone is a criteria pollutant for which NAAQS are
established. On July 18, 1997, EPA promulgated a revised 8-hour ozone
NAAQS of 0.08 parts per million (ppm).\1\ These NAAQS are more
stringent than the previous 1-hour ozone NAAQS. Under EPA regulations
found at 40 CFR part 50, the 1997 8-hour ozone NAAQS are attained when
the 3-year average of the annual fourth-highest daily maximum 8-hour
average ambient air quality ozone concentrations is less than or equal
to 0.08 ppm (i.e., 0.084 ppm when rounding is considered). (See 69 FR
23857 (April 30, 2004) for further information.) Ambient air quality
monitoring data for the 3-year period must meet a data completeness
requirement. The ambient air quality monitoring data completeness
requirement is met when the percent of days with valid ambient
monitoring data is greater than 90 percent, on average, and no single
year has less than 75 percent data completeness as determined in
Appendix I of part 50. Specifically, section 2.3 of 40 CFR part 50,
Appendix I, ``Comparisons with the Primary and Secondary Ozone
Standards'' states:
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    \1\ Ground-level ozone is not emitted directly by sources.
Rather, emissions of NOX and VOC react in the presence of
sunlight to form ground-level ozone. As a result, NOX and
VOC are referred to as precursors of ozone.

    The primary and secondary ozone ambient air quality standards
are met at an ambient air quality monitoring site when the 3-year
average of the annual fourth-highest daily maximum 8-hour average
ozone concentration is less than or equal to 0.08 ppm. The number of
significant figures in the level of the standard dictates the
rounding convention for comparing the computed 3-year average annual
fourth-highest daily maximum 8-hour average ozone concentration with
the level of the standard. The third decimal place of the computed
value is rounded, with values equal to or greater than 5 rounding
up. Thus, a computed 3-year average ozone concentration of 0.085 ppm
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is the smallest value that is greater than 0.08 ppm.

    The CAA required EPA to designate as nonattainment any area that
was violating the 1997 8-hour ozone NAAQS based on the three most
recent years of ambient air quality data. The Knoxville Area was
initially designated nonattainment for the 1997 8-hour ozone NAAQS
using 2001-2003 ambient air quality data. The Federal Register document
making these designations was published on April 30, 2004 (69 FR
23857).
    The CAA contains two sets of provisions--subpart 1 and subpart 2--
that address planning and control requirements for ozone nonattainment
areas. (Both are found in title I, part D.) Subpart 1 (which EPA refers
to as ``basic'' nonattainment) contains general, less prescriptive,
requirements for nonattainment areas for any pollutant--including
ozone--governed by a NAAQS. Subpart 2 (which EPA refers to as
``classified'' nonattainment) provides more specific requirements for
certain ozone nonattainment areas. Under EPA's Phase I 1997 8-Hour
Ozone Implementation Rule (69 FR 23857) (Phase I Rule), published April
30, 2004, an area was classified under subpart 2 based on its 1997 8-
hour ozone design value (i.e., the 3-year average of the annual fourth-
highest daily maximum 8-hour average ozone concentrations), if it had a
1-hour design value at or above 0.121 ppm (the lowest 1-hour design
value in Table 1 of subpart 2). All other areas were covered under
subpart 1, based upon their 8-hour ambient air quality design values.
    Knox County (which is a part of the Knoxville Area) was originally
designated as marginal nonattainment for the 1-hour ozone NAAQS on
November 6, 1991 (56 FR 56694). Knox County was redesignated as
attainment for the 1-hour ozone NAAQS on September 27, 1993 (58 FR
50271). At that same time, Anderson, Blount, Cocke, Jefferson, Loudon
and Sevier Counties in their entireties were designated attainment/
unclassifiable for the 1-hour ozone NAAQS. On April 30, 2004, EPA
designated the Knoxville Area (of which Knox County is a part) as a
``basic'' (subpart 1) 8-hour ozone nonattainment area (69 FR 23857,
April 30, 2004). When Tennessee submitted

its final redesignation request on July 14, 2010, the Knoxville Area
was classified under subpart 1 of the CAA, and was obligated to meet
only the subpart 1 requirements.
    EPA promulgated implementation rules for the 1997 8-hour ozone
NAAQS. These rules were published in 2 phases. The Phase I
Implementation Rule (69 FR 23951, April 30, 2004) was published at the
same time as the ozone designations and addresses such topics as
classifications, revocation of the 1-hour NAAQS, anti-backsliding
principles, and timing for emission reductions. The Phase II Rule was
published November 29, 2005, (72 FR 31727) and addressed remaining
implementation issues not covered by the Phase 1 Rule. Various aspects
of EPA's Phase 1 Rule were challenged in court. On December 22, 2006,
the U.S. Court of Appeals for the District of Columbia Circuit (DC
Circuit Court) vacated EPA's Phase 1 Rule (69 FR 23951, April 30,
2004). South Coast Air Quality Management Dist. (SCAQMD) v. EPA, 472
F.3d 882 (DC Cir. 2006). On June 8, 2007, in response to several
petitions for rehearing, the DC Circuit Court clarified that the Phase
I Rule was vacated only with regard to those parts of the Rule that had
been successfully challenged. Therefore, the Phase I Rule provisions
related to classifications for areas currently classified under subpart
2 of title I, part D of the CAA as 1997 8-hour ozone NAAQS
nonattainment areas, the 1997 8-hour ozone NAAQS attainment dates and
the timing for emissions reductions needed for attainment of the 1997
8-hour ozone NAAQS remain effective. The June 8th decision left intact
the court's rejection of EPA's reasons for implementing the 1997 8-hour
NAAQS in certain nonattainment areas under subpart 1 in lieu of subpart
2, i.e., the court's rejection of the subpart 1 classification. By
limiting the vacatur, the court let stand EPA's revocation of the 1-
hour NAAQS and those anti-backsliding provisions of the Phase I Rule
that had not been successfully challenged. The June 8th decision
reaffirmed the December 22, 2006, decision that EPA had improperly
failed to retain measures required for 1-hour nonattainment areas under
the anti-backsliding provisions of the regulations: (1) Nonattainment
area New Source Review (NSR) requirements based on an area's 1-hour
nonattainment classification; (2) Section 185 penalty fees for 1-hour
severe or extreme nonattainment areas; and (3) measures to be
implemented pursuant to section 172(c)(9) or 182(c)(9) of the CAA, on
the contingency of an area not making reasonable further progress (RFP)
toward attainment of the 1-hour NAAQS, or for failure to attain that
NAAQS. The June 8th decision clarified that the court's reference to
conformity requirements for anti-backsliding purposes was limited to
requiring the continued use of 1-hour MVEBs until 1997 8-hour ozone
NAAQS budgets were available for 8-hour ozone conformity
determinations, which is already required under EPA's conformity
regulations. The court thus clarified that 1-hour ozone conformity
determinations are not required for anti-backsliding purposes.
    This section sets forth EPA's views on the potential effect of the
court's rulings on this proposed redesignation action. For the reasons
set forth below, EPA does not believe that the court's rulings alter
any requirements relevant to this redesignation action so as to
preclude redesignation, nor does EPA believe the court's ruling
prevents EPA from proposing or ultimately finalizing this
redesignation. EPA believes that the court's December 22, 2006, and
June 8, 2007, decisions impose no impediment to moving forward with
redesignation of the Knoxville Area to attainment.
    With respect to the 1997 8-hour ozone NAAQS, the court's ruling
rejected EPA's reasons for classifying areas under subpart 1 for the
1997 8-hour ozone NAAQS, and remanded that matter back to the Agency.
In its January 16, 2009, proposed rulemaking in response to the SCAQMD
decision, EPA has proposed to classify the Knoxville Area under subpart
2 as a moderate area (74 FR 2936). If EPA finalizes the
reclassification of the Knoxville Area before the July 14, 2010,
redesignation request is approved, the requirements under subpart 2
will become applicable when they are due. EPA proposed a deadline for
submission of these requirements of one year after the effective date
of the final rulemaking classifying this and other areas (74 FR 2940-
2941). However, EPA believes that this does not preclude this
redesignation from being approved. This belief is based upon: (1) EPA's
longstanding policy of evaluating requirements in accordance with the
requirements due at the time redesignation request is submitted; and
(2) consideration of the inequity of applying retroactively any
requirements that might in the future be applied.
    First, at the time the redesignation request was submitted, the
Knoxville Area was not classified under subpart 2, nor were subpart 2
requirements yet due for this Area. Under EPA's longstanding
interpretation of section 107(d)(3)(E) of the CAA, to qualify for
redesignation, states requesting redesignation to attainment must meet
only the relevant SIP requirements that came due prior to the submittal
of a complete redesignation request. September 4, 1992, Calcagni
Memorandum (``Procedures for Processing Requests to Redesignate Areas
to Attainment,'' Memorandum from John Calcagni, Director, Air Quality
Management Division). See also the September 17, 1993, Michael Shapiro
Memorandum (''State Implementation Plan (SIP) Requirements for Areas
Submitting Requests for Redesignation to Attainment of the Ozone and
Carbon Monoxide (CO) National Ambient Air Quality Standards (NAAQS) on
or after November 15, 1992,'' Memorandum from Michael Shapiro, Acting
Assistant Administrator for Air and Radiation), and 60 FR 12459, 12465-
66 (March 7, 1995) (Redesignation of Detroit-Ann Arbor, Michigan);
Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 2004) (upholding this
interpretation); 68 FR 25418, 25424, 25427 (May 12, 2003)
(redesignation of St. Louis, Missouri).
    Moreover, it would be inequitable to retroactively apply any new
SIP requirements that were not applicable at the time the request was
submitted. The DC Circuit Court has recognized the inequity in such
retroactive rulemaking (see Sierra Club v. Whitman 285 F. 3d 63 (DC
Cir. 2002)), in which the court upheld a district court's ruling
refusing to make retroactive an EPA determination of nonattainment that
was past the statutory due date. Such a determination would have
resulted in the imposition of additional requirements on the area. The
court stated, ``[a]lthough EPA failed to make the nonattainment
determination within the statutory frame, Sierra Club's proposed
solution only makes the situation worse. Retroactive relief would
likely impose large costs on the states, which would face fines and
suits for not implementing air pollution prevention plans in 1997, even
though they were not on notice at the time.'' Id. at 68. Similarly
here, it would be unfair to penalize the Knoxville Area by applying to
it, for purposes of redesignation, additional SIP requirements under
subpart 2 that were not in effect or yet due at the time it submitted
its redesignation request, or the time that the Knoxville Area attained
the NAAQS.
    With respect to the requirements under the 1-hour ozone NAAQS, only
the Knox County portion of the Knoxville Area was originally designated
as a marginal nonattainment for the 1-hour ozone NAAQS in November 6,
1991 (56 FR 56694); the remainder of the Knoxville Area was

designated as attainment. Knox County was redesignated as attainment
for the 1-hour ozone NAAQS on September 27, 1993 (58 FR 50271).
Therefore, Knox County was redesignated to attainment of the 1-hour
ozone NAAQS prior to its nonattainment designation for the 1997 8-hour
ozone NAAQS. As a result, Knox County (as part of the Knoxville Area)
is considered to be a 1-hour attainment area subject to a CAA section
175A maintenance plan for the 1-hour ozone NAAQS. The DC Circuit
Court's decisions do not impact redesignation requests for these types
of areas, except to the extent that the court, in its June 8th
decision, clarified that for those areas with 1-hour MVEBs in their
maintenance plans, anti-backsliding requires that those 1-hour budgets
must be used for 8-hour conformity determinations until they are
replaced by 1997 8-hour budgets. To meet this requirement, conformity
determinations in such areas must comply with the applicable
requirements of EPA's conformity regulations at 40 CFR part 93.
    First, there are no conformity requirements relevant for evaluating
the Knoxville Area redesignation request, such as a transportation
conformity SIP.\2\ It is EPA's longstanding policy that it is
reasonable to interpret the conformity SIP requirements as not applying
for purposes of evaluating a 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 40 CFR 51.390; see also Wall v. EPA, 265 F.3d 426 (6th
Cir. 2001) (upholding EPA's interpretation); 60 FR 62748 (Dec. 7, 1995)
(redesignation of Tampa, Florida). Tennessee currently has a fully
approved 1-hour ozone transportation conformity SIP, which was approved
on May 16, 2003 (68 FR 26492).
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    \2\ 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 motor vehicle emission budgets that are
established in control strategy SIPs and maintenance plans.
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    Second, with regard to the three other anti-backsliding provisions
for the 1-hour standard that the DC Circuit Court found were not
properly retained, Knox County, Tennessee is an attainment area subject
to a maintenance plan for the 1-hour standard, and the NSR requirement
no longer applies to this area because it was redesignated to
attainment of the 1-hour standard. Because Knox County was redesignated
as a 1-hour attainment area, the contingency measure (pursuant to
section 172(c)(9) or 182(c)(9)) and fee provision requirements no
longer apply to the Knoxville Area. As a result, the decisions in
SCAQMD should not alter any requirements that would preclude EPA from
finalizing the redesignation of the Knoxville Area to attainment for
the 1997 8-hour ozone NAAQS.
    As was noted earlier, in 2009, the ambient ozone data for the
Knoxville Area indicated no further violations of the 1997 8-hour ozone
NAAQS, using data from the 3-year period of 2007-2009 to demonstrate
attainment. As a result, on July 14, 2010, Tennessee requested
redesignation of the Knoxville Area to attainment for the 1997 8-hour
ozone NAAQS. The redesignation request included three years of
complete, quality-assured ambient air quality data for the ozone
seasons (March 1st through October 31st) of 2007-2009, indicating that
the 1997 8-hour ozone NAAQS has been achieved for the entire Knoxville
Area. Under the CAA, nonattainment areas may be redesignated to
attainment if sufficient, complete, quality-assured data is available
for the Administrator to determine that the area has attained the
standard and the area meets the other CAA redesignation requirements in
section 107(d)(3)(E). The 1997 8-hour ozone design values for the
Knoxville Area indicate that between 1999 and 2009, ozone
concentrations declined noticeably at both high and low evaluations.
While ozone concentrations are dependent on a variety of conditions,
the likely reason for the overall downtrend in ozone concentrations in
the Knoxville Area is most likely due to the reduction of NOx emissions
that have occurred since 2004.

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 providing that: (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 for purposes of redesignation under
section 110 and part D 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 supplemented this guidance on
April 28, 1992 (57 FR 18070). EPA has provided further guidance on
processing redesignation requests in the following documents:
    1. ``Ozone and Carbon Monoxide Design Value Calculations,''
Memorandum from Bill Laxton, Director, Technical Support Division, June
18, 1990;
    2. ``Maintenance Plans for Redesignation of Ozone and Carbon
Monoxide Nonattainment Areas,'' Memorandum from G. T. Helms, Chief,
Ozone/Carbon Monoxide Programs Branch, April 30, 1992;
    3. ``Contingency Measures for Ozone and Carbon Monoxide (CO)
Redesignations,'' Memorandum from G. T. Helms, Chief, Ozone/Carbon
Monoxide Programs Branch, June 1, 1992;
    4. ``Procedures for Processing Requests to Redesignate Areas to
Attainment,'' Memorandum from John Calcagni, Director, Air Quality
Management Division, September 4, 1992 (hereafter referred to as the
``Calcagni Memorandum'');
    5. ``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;
    6. ``Technical Support Documents (TSDs) for Redesignation of Ozone
and Carbon Monoxide (CO) Nonattainment Areas,'' Memorandum from G. T.
Helms, Chief, Ozone/Carbon Monoxide Programs Branch, August 17, 1993;
    7. ``State Implementation Plan (SIP) Requirements for Areas
Submitting Requests for Redesignation to Attainment of the Ozone and
Carbon Monoxide (CO) National Ambient Air Quality Standards (NAAQS) On
or After November 15, 1992,'' Memorandum from Michael H. Shapiro,
Acting Assistant Administrator for Air and Radiation, September 17,
1993;
    8. ``Use of Actual Emissions in Maintenance Demonstrations for
Ozone and CO Nonattainment Areas,'' Memorandum from D. Kent Berry,
Acting Director, Air Quality Management Division, November 30, 1993;
    9. ``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; and
    10. ``Reasonable Further Progress, Attainment Demonstration, and
Related Requirements for Ozone Nonattainment Areas Meeting the Ozone
National Ambient Air Quality Standard,'' Memorandum from John S. Seitz,
Director, Office of Air Quality Planning and Standards, May 10, 1995.

IV. Why is EPA proposing these actions?

    On July 14, 2010, Tennessee, through TDEC, requested redesignation
of the Knoxville Area to attainment for the 1997 8-hour ozone NAAQS.
EPA's evaluation indicates that the Knoxville Area has attained the
1997 8-hour ozone NAAQS and has met the requirements for redesignation
set forth in section 107(d)(3)(E), including the maintenance plan
requirements under section 175A of the CAA. EPA is also proposing to
approve the 2007 baseline emission inventory under section 172(c)(3)
because Tennessee has used methodology consistent with EPA guidance and
implementing regulations to develop this inventory. EPA is also
announcing the status of its adequacy determination of the 2024
NOX and VOC MVEBs which are relevant to the requested
redesignation.

V. 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 today. Approval
of Tennessee's redesignation request would change the legal designation
of the Anderson, Blount, Jefferson, Knox, Loudon, and Sevier Counties
in their entireties, and the portion of Cocke County that falls within
the boundary of the Great Smoky Mountains National Park for the 1997 8-
hour ozone NAAQS found at 40 CFR part 81 from nonattainment to
attainment. Approval of Tennessee's request would also incorporate into
the Tennessee SIP, a plan for maintaining the 1997 8-hour ozone NAAQS
in the Knoxville Area through 2024. This maintenance plan includes
contingency measures to remedy future violations of the 1997 8-hour
ozone NAAQS. The maintenance plan also establishes NOX and
VOC MVEBs for the Knoxville Area. The NOX and VOC MVEBs for
2024 for the Knoxville Area are 36.32 tons per day (tpd) and 25.19 tpd,
respectively. Final action would also approve the Area's emissions
inventory under section 172(c)(3). Approval of Tennessee's maintenance
plan would also result in approval of the NOX and VOC MVEBs.
Additionally, EPA is notifying the public of the status of its adequacy
determination for the 2024 NOX and VOC MVEBs pursuant to 40
CFR 93.118(f)(1).

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

    EPA is proposing to make the determination that the Knoxville 1997
8-hour ozone nonattainment area has attained the 1997 8-hour ozone
NAAQS, and that all other redesignation criteria have been met for the
Knoxville Area. The basis for EPA's determination for the Area is
discussed in greater detail below.

Criteria (1)--The Knoxville Area Has Attained the 1997 8-Hour Ozone
NAAQS

    EPA is proposing to determine that the Knoxville Area has attained
the 1997 8-hour ozone NAAQS. For ozone, an area may be considered to be
attaining the 1997 8-hour ozone NAAQS if it meets the 1997 8-hour ozone
standard, as determined in accordance with 40 CFR 50.10 and Appendix I
of part 50, based on three complete, consecutive calendar years of
quality-assured air quality monitoring data. To attain these NAAQS, the
3-year average of the fourth-highest daily maximum 8-hour average ozone
concentrations measured at each monitor within an area over each year
must not exceed 0.08 ppm. Based on the data handling and reporting
convention described in 40 CFR part 50, appendix I, the NAAQS are
attained if the design value is 0.084 ppm or below. The data must be
collected and quality-assured in accordance with 40 CFR part 58, and
recorded in the EPA Air Quality System (AQS). The monitors generally
should have remained at the same location for the duration of the
monitoring period required for demonstrating attainment.
    EPA reviewed ozone monitoring data from ambient ozone monitoring
stations in the Knoxville Area for the ozone season from 2007-2009.
These data have been quality-assured and are recorded in AQS. The
fourth-highest 8-hour ozone average for 2007, 2008 and 2009, and the 3-
year average of these values (i.e., design values), are summarized in
the following Table 1 of this proposed rulemaking.

                 Table 1--Design Value Concentrations for the Knoxville 8-Hour Ozone Area (ppm)
----------------------------------------------------------------------------------------------------------------
                                                                          Eight-hour design values (ppm)
          County                  Site name         Monitor ID   -----------------------------------------------
                                                                     2005-2007       2006-2008       2007-2009
----------------------------------------------------------------------------------------------------------------
Anderson..................  Freels Bend Study        470010101-1           0.080           0.077           0.072
                             Area.
Blount....................  Look Rock, GSMNP....     470090101-1           0.086           0.085           0.079
                            Cades Cove, GSMNP...     470090102-1           0.070           0.072           0.069
Jefferson.................  1188 Lost Creek Road     470890002-1           0.084           0.081           0.076
Knox......................  9315 Rutledge Pike..     470930021-1           0.081           0.081           0.077
                            4625 Mildred Drive..     470931020-1           0.088           0.088           0.082
Loudon....................  1703 Roberts Road...      47105109-1           0.085           0.082           0.077
Sevier....................  Cove Mountain, GSMNP      47155101-1           0.082           0.082           0.079
----------------------------------------------------------------------------------------------------------------

    As discussed above, the design value for an area is the highest 3-
year average of the annual fourth-highest 8-hour ozone value recorded
at any monitor in the area. Therefore, the most recent 3-year design
value (2007-2009) for the Knoxville Area is 0.082 ppm, which meets the
NAAQS as described above. Current air quality data show that the Area
continues to attain the NAAQS. If the Area does not continue to attain
until EPA finalizes the redesignation, EPA will not go forward with the
redesignation. As discussed in more detail below, the State of
Tennessee has committed to continue monitoring in this Area in
accordance with 40 CFR part 58. EPA proposes to find that the Knoxville
Area has attained the 1997 8-hour ozone NAAQS.

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

    Below is a summary of how these two criteria were met.
    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. EPA also
proposes to find that the Tennessee SIP satisfies the criterion that it
meet applicable SIP requirements for purposes of redesignation under
part D of title I of the CAA (requirements specific to subpart 1 basic
1997 8-hour ozone nonattainment areas) in accordance with section
107(d)(3)(E)(v). In addition, 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). In making
these determinations, EPA ascertained which requirements are applicable
to the Area and that if applicable, they are fully approved under
section 110(k). SIPs must be fully approved only with respect to
applicable requirements.
a. Knoxville Area Has Met All Applicable Requirements Under Section 110
and Part D of the CAA
    The September 4, 1992, Calcagni Memorandum describes EPA's
interpretation of section 107(d)(3)(E). Under this interpretation, to
qualify for redesignation, states requesting redesignation to
attainment must meet only the relevant CAA requirements that come due
prior to the submittal of a complete redesignation request. See also
Michael Shapiro Memorandum, (``SIP Requirements for Areas Submitting
Requests for Redesignation to Attainment of the Ozone and Carbon
Monoxide NAAQS On or After November 15, 1992,'' September 17, 1993); 60
FR 12459, 12465-66 (March 7, 1995) (redesignation of Detroit-Ann Arbor,
Michigan). Applicable requirements of the CAA that come due subsequent
to the area's submittal of a complete redesignation request remain
applicable until a redesignation is approved, but are not required as a
prerequisite to redesignation. See section 175A(c) of the CAA; Sierra
Club, 375 F.3d 537; see also 68 FR 25424, 25427 (May 12, 2003)
(redesignation of St. Louis, Missouri).
    General SIP requirements. Section 110(a)(2) of title I of the CAA
delineates the general requirements for a SIP, which include
enforceable emissions limitations and other control measures, means, or
techniques, provisions for the establishment and operation of
appropriate devices necessary to collect data on ambient air quality,
and programs to enforce the limitations. 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 (NSR 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 transport
of air pollutants (NOX SIP Call \3\ and Clean Air Interstate
Rule (CAIR \4\)). 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, we do not believe that the CAA's
interstate transport requirements should be construed to be applicable
requirements for purposes of redesignation.
---------------------------------------------------------------------------

    \3\ On October 27, 1998 (63 FR 57356), EPA issued a
NOX SIP Call requiring the District of Columbia and 22
states to reduce emissions of NOX in order to reduce the
transport of ozone and ozone precursors. In compliance with EPA's
NOX SIP Call, Tennessee developed rules governing the
control of NOX emissions from Electric Generating Units
(EGUs), major non-EGU industrial boilers, major cement kilns, and
internal combustion engines. On January 22, 2004, EPA approved
Tennessee's rules as fulfilling Phase I (69 FR 3015) and Phase II on
December 27, 2005 (70 FR 76408).
    \4\ On May 12, 2005 (70 FR 25162), EPA promulgated CAIR which
required 28 upwind States and the District of Columbia to revise
their SIPs to include control measures that would reduce emissions
of sulfur dioxide and NOX. Various aspects of CAIR rule
were petitioned in court and on December 23, 2008, the U.S. Court of
Appeals for the District of Columbia Circuit remanded CAIR to EPA
(see North Carolina v. EPA, 550 F.3d 1176 (DC Cir., 2008)) which
left CAIR in place to ``temporarily preserve the environmental
values covered by CAIR'' until EPA replaces it with a rule
consistent with the court's decision. The court directed EPA to
remedy various areas of the rule that were petitioned consistent
with its July 11, 2008, opinion (see, North Carolina v. EPA, 531
F.3d 836 (DC Cir., 2008)), but declined to impose a schedule on EPA
for completing that action. Id. Therefore, CAIR is currently in
effect in Tennessee.
---------------------------------------------------------------------------

    In addition, EPA believes that the other section 110 elements not
connected with nonattainment plan submissions and not 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 37890, June 19, 2000), and in the
Pittsburgh, Pennsylvania redesignation (66 FR 50399, October 19, 2001).
    EPA believes that section 110 elements not linked to the area's
nonattainment status are not applicable for purposes of redesignation.
Therefore, as was discussed above, for purposes of redesignation, they
are not considered applicable requirements. Nonetheless, EPA notes it
has previously approved provisions in the Tennessee SIP addressing
section 110 elements under the 1-hour ozone NAAQS (45 FR 53809, August
13, 1980). The State believes that the section 110 SIP approved for the
1-hour ozone NAAQS are sufficient to meet the requirements under the
1997 8-hour ozone NAAQS. Tennessee submitted a letter dated December
14, 2007, setting forth its belief that the section 110 SIP approved
for the 1-hour ozone NAAQS is also sufficient to meet the requirements
under the 1997 8-hour ozone NAAQS. EPA has not yet approved this
submission, but such

approval is not necessary for purposes of redesignation.
    Part D requirements. EPA proposes that if EPA approves Tennessee's
base year emissions inventory, which is part of the maintenance plan
submittal, the Tennessee SIP will meet applicable SIP requirements
under part D of the CAA. We believe the emissions inventory is
approvable because the 2007 VOC and NOx emissions for
Tennessee were developed consistent with EPA guidance for emission
inventories, and the choice of the 2007 base year is appropriate
because it represents the 2007-2009 period when the 1997 8-hour ozone
NAAQS were not violated.
    Part D, subpart 1 applicable SIP requirements. EPA has determined
that, if EPA finalizes the approval of the base year emissions
inventories discussed in section IX of this rulemaking, the Tennessee
SIP will meet the applicable SIP requirements for the Knoxville Area
applicable for purposes of redesignation under part D of the CAA.
Subpart 1 of part D, found in sections 172-176 of the CAA, sets for the
basic nonattainment requirements applicable to all nonattainment areas.
Subpart 2 of part D, which includes section 182 of the CAA, establishes
additional specific requirements depending on the area's nonattainment
classification. Since the Knoxville Area was not classified under
subpart 2 at the time the redesignation request was submitted, the
subpart 2 requirements do not apply for purposes of evaluating the
Tennessee's redesignation request. The applicable subpart 1
requirements are contained in sections 172(c)(1)-(9) and in section
176. A thorough discussion of the requirements contained in section 172
can be found in the General Preamble for Implementation of title I (57
FR 13498).
    Subpart 1 Section 172 Requirements.\5\ For purposes of evaluating
this redesignation request, the applicable section 172 SIP requirements
for the Knoxville Area are contained in sections 172(c)(1)-(9). A
thorough discussion of the requirements contained in section 172 can be
found in the General Preamble for Implementation of Title I (57 FR
13498, April 16, 1992).
---------------------------------------------------------------------------

    \5\ On August 3, 2010, EPA proposed to approve a clean data
determination for the Knoxville Area for the 1997 8-hour ozone NAAQS
(75 FR 45568). If EPA takes final action on this determination,
under the provisions of EPA's ozone implementation rule (see 40 CFR
Section 51.918), the requirements for the State of Tennessee to
submit an attainment demonstration and associated reasonably
available control measures plan, RFP plan, contingency measures, and
any other planning SIPs related to attainment of the 1997 8-hour
ozone NAAQS for the Knoxville Area, shall be suspended for as long
as the Area continues to meet the 1997 8-hour ozone NAAQS.
---------------------------------------------------------------------------

    Section 172(c)(1) requires the plans for all nonattainment areas to
provide for the implementation of all reasonably available control
measures (RACM) as expeditiously as practicable and to provide for
attainment of the national primary ambient air quality standards. EPA
interprets this requirement to impose a duty on all nonattainment areas
to consider all available control measures and to adopt and implement
such measures as are reasonably available for implementation in each
area as components of the area's attainment demonstration.
    The RFP plan requirement under section 172(c)(2) is defined as
progress that must be made toward attainment. This requirement is not
relevant for purposes of redesignation because the Knoxville Area has
monitored attainment of the ozone NAAQS. (General Preamble, 57 FR
13564). See also 40 CFR 51.918. In addition, because the Knoxville Area
has attained the ozone NAAQS and is no longer subject to an RFP
requirement, the requirement to submit the section 172(c)(9)
contingency measures is not applicable for purposes of redesignation.
Id.
    Section 172(c)(3) requires submission and approval of a
comprehensive, accurate, and current inventory of actual emissions. As
part of Tennessee's redesignation request for the Knoxville Area,
Tennessee submitted a 2007 base year emissions inventory. As discussed
below in section IX, EPA is proposing to approve the 2007 base year
inventory that Tennessee submitted with the redesignation request as
meeting the section 172(c)(3) emissions inventory requirement.
    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 NSR program be
approved prior to redesignation, provided that the area demonstrates
maintenance of the NAAQS without part D NSR. A more detailed rationale
for this view is described in a memorandum from Mary Nichols, Assistant
Administrator for Air and Radiation, dated October 14, 1994, entitled,
``Part D New Source Review Requirements for Areas Requesting
Redesignation to Attainment.'' Tennessee has demonstrated that the
Knoxville Area will be able to maintain the NAAQS without part D NSR in
effect; therefore, EPA concludes that Tennessee need not have fully
approved part D NSR programs prior to approval of the redesignation
request. Tennessee's PSD programs will become effective in the
Knoxville Area upon redesignation to attainment. See rulemakings for
Detroit, Michigan (60 FR 12467-12468, March 7, 1995); Cleveland-Akron-
Lorain, Ohio (61 FR 20458, 20469-20470, May 7, 1996); Louisville,
Kentucky (66 FR 53665, October 23, 2001); and Grand Rapids, Michigan
(61 FR 31834-31837, June 21, 1996).
    Section 172(c)(6) requires the SIP to contain control measures
necessary to provide for attainment of the NAAQS. Because attainment
has been reached, no additional measures are needed to provide for
attainment.
    Section 172(c)(7) requires the SIP to meet the applicable
provisions of section 110(a)(2). As noted above, we believe the
Tennessee SIP meets the requirements of section 110(a)(2) applicable
for purposes of redesignation.
    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
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 it is reasonable to interpret the conformity SIP
requirements \6\ 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, 265
F.3d 426 (upholding this interpretation);

see also 60 FR 62748 (December 7, 1995, Tampa, Florida). Tennessee
submitted its transportation conformity SIP for 1-hour ozone on March
19, 2002. EPA issued a direct final rule approving Tennessee's
Transportation Conformity SIP on May 16, 2003 (68 FR 26492).
---------------------------------------------------------------------------

    \6\ 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 motor vehicle emission budgets that are
established in control strategy SIPs and maintenance plans.
---------------------------------------------------------------------------

    NSR Requirements. EPA has also determined that areas being
redesignated need not comply with the requirement that a NSR program be
approved prior to redesignation, provided that the area demonstrates
maintenance of the NAAQS without a part D NSR program in effect since
PSD requirements will apply after redesignation. The rationale for this
view is described in a memorandum from Mary Nichols, Assistant
Administrator for Air and Radiation, dated October 14, 1994, entitled
``Part D New Source Review (Part D NSR) Requirements for Areas
Requesting Redesignation to Attainment.'' Tennessee has demonstrated
that the Knoxville Area will be able to maintain the NAAQS without a
part D NSR program in effect, and therefore, Tennessee need not have a
fully-approved part D NSR program prior to approval of the
redesignation request. However, Tennessee currently has a fully-
approved part D NSR program in place. Tennessee's PSD program will
become effective in the Knoxville Area upon redesignation to
attainment. See rulemakings for Detroit, Michigan (60 FR 12467-12468,
March 7, 1995); Cleveland-Akron-Lorraine, Ohio (61 FR 20458, 20469-70,
May 7, 1996); Louisville, Kentucky (66 FR 53665, October 23, 2001); and
Grand Rapids, Michigan (61 FR 31834-31837, June 21, 1996). Thus, the
Knoxville Area has satisfied all applicable requirements for purposes
of redesignation under section 110 and part D of the CAA.
b. The Knoxville Area Has a Fully Approved Applicable SIP Under Section
110(k) of the CAA
    If EPA issues a final approval of the base year emissions
inventories, EPA will have fully approved the applicable Tennessee SIP
for the Knoxville 8-hour ozone nonattainment area, under section 110(k)
of the CAA for all requirements applicable for purposes of
redesignation. 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, 989-90 (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 1-hour ozone NAAQS SIP
elements applicable in Knox County, Tennessee (58 FR 50271, September
27, 1993; and 69 FR 4852, February 2, 2004).
    As indicated above, EPA believes that the section 110 elements not
connected with nonattainment plan submissions and not linked to the
area's nonattainment status are not applicable requirements for
purposes of redesignation. EPA also believes that since the part D
subpart 1 requirements did not become due prior to submission of the
redesignation request, they also are therefore not applicable
requirements for purposes of redesignation. Sierra Club v. EPA, 375
F.3d 537 (7th Cir. 2004); 68 FR 25424, 25427 (May 12, 2003)
(redesignation of the St. Louis-East St. Louis Area to attainment of
the 1-hour ozone NAAQS). With the approval of the emissions inventory,
EPA will have approved all Part D subpart 1 requirements applicable for
purposes of redesignation.

Criteria (3)--The Air Quality Improvement in the Knoxville Area 1997 8-
Hour Ozone NAAQS Nonattainment 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

    EPA believes 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 implementation of
the SIP, Federal measures, and other state adopted measures.
Additionally, new emissions control programs for fuels and motor
vehicles will help ensure a continued decrease in emissions throughout
the region.
    Measured reductions in ozone concentrations in and around the
Knoxville Area are largely attributable to reductions from emission
sources of VOC and NOX, which are precursors in the
formation of ozone. Table 2 summarizes several of the measures adopted
that contributed to reductions of emissions. The majority of these
reductions have been realized from federal measures related to mobile
sources and electrical power generation.

Table 2--Federal and State Measures Contributing to Emissions Reductions
------------------------------------------------------------------------

-------------------------------------------------------------------------
Federal Measures:
  NOX Budget Trading Program.
  NOX SIP call.
  National Low Emission Vehicles.
  Tier 2 Vehicle Standards.
  Tier 1, Tier 2 and Tier 3 (non-road).
  Sources-Spark Ignition Engines (non-road).
State and Local Measures:
  Stage I Vapor Recovery.
  Motor Vehicle Anti-tampering Rule.
  Air Quality Alert Programs.
  Smart Trips Program.
------------------------------------------------------------------------

    One key program, the NOX SIP, required states to make
significant, specific emissions reductions (63 FR 57356). It also
provided a mechanism, the NOX Budget Trading Program, which
states could use to achieve those reductions. When EPA promulgated
CAIR, it discontinued (starting in 2009) the NOX Budget
Trading Program, 40 CFR 51.121(r), but created another mechanism--the
CAIR ozone season trading program--which states could use to meet their
SIP Call obligations, 70 FR 25289-90. All NOX SIP Call
states have SIPs that currently satisfy their obligations under the SIP
Call, the SIP Call reduction requirements are being met, and EPA will
continue to enforce the requirements of the NOX SIP Call
even after any response to the CAIR remand. Notably, the anti-
backsliding provisions of 40 CFR 51.905(f) specifically provide that
the provisions of the NOX SIP Call, including the statewide
NOX emission budgets, continue to apply after revocation of
the 1-hour standard.
    Regarding point source emissions, the Tennessee Valley Authority's
(TVA's) Bull Run Steam Plant located in Anderson County and Kingston
Steam Plant located in Roane County include a total of 10 coal-fired
boilers. As a result of EPA's ``Finding of Significant Contribution and
Rulemaking for Certain States in the Ozone Transport Assessment Group
Region for Purposes of Reducing Region Transport of Ozone''
(NOX SIP Call), TVA began operation of selective catalytic
reduction (SCR) systems in 2004 at Bull Run's unit and on eight of the
nine units at Kingston. TVA began operation of a SCR for the ninth unit
at Kingston in 2006. There was an 85 percent and 90 percent reduction
in NOX emissions from the Bull Run and Kingston facilities,
respectively from 2003 to 2008 as a result of these controls.
Furthermore, NOX emissions from all categories are projected
to decrease in the Knoxville Area by 56.1 tpd between 2007 and

2024 (41.5 percent reduction). Total point source NOX
emissions are projected to increase slightly (2.42 tpd), while EGU
NOX emissions are projected to remain unchanged between 2007
and 2024. For these reasons, EPA believes that regardless of the status
of the CAIR program, the NOX SIP call requirements can be
relied upon in demonstrating maintenance. Here, Tennessee has
demonstrated maintenance based in part on those requirements.
    In addition, EPA undertook an analysis of the changes in
NOX expected across a broader region. In particular, EPA
reviewed available projections of NOX emissions from nearby
states from 2002 to 2018.

                                              Table 3--2002 Base Annual Emission Inventory Summary for NOX*
                                                                     [Tons per year]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                 States                      EGU point     Non-EGU point     Non-road          Area           Mobile           Fires           Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
AR......................................          24,722          47,698          62,472          21,700         141,894           5,492         303,978
KY......................................         201,928          38,434         104,571          39,507         156,417             534         541,391
LA......................................         111,703         199,218         114,711          93,069         180,664           6,942         706,307
MS......................................          40,433          61,533          88,787           4,200         111,914             308         307,175
MO......................................         145,438          36,144          99,306          32,435         189,852           2,442         505,617
TN......................................         152,137          64,344          96,827          17,844         238,577             217         569,946
                                         ---------------------------------------------------------------------------------------------------------------
    Total...............................         676,361         447,371         566,674         208,755       1,019,318          15,935       2,934,414
--------------------------------------------------------------------------------------------------------------------------------------------------------
* From the Tennessee Regional Haze SIP, Appendix D, page D.3-5 and support table for Technical Support Document for CENRAP Emissions and Air Quality
  Modeling to Support Regional Haze State Implementation Plans, page 2-40, figure 2-4.

                                             Table 4--2018 Base Annual Emission Inventory Summary for NOX *
                                                                     [Tons per year]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                 States                      EGU point     Non-EGU point     Non-road          Area           Mobile           Fires           Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
AR......................................          34,938          36,169          34,305          25,672          33,640           5,600         170,324
KY......................................          64,378          41,034          79,392          44,346          52,263             714         282,127
LA......................................          44,485         225,748         106,685         114,374          44,806           6,969         543,067
MS......................................          21,535          61,252          68,252           4,483          30,619           1,073         187,214
MO......................................          83,181          51,489          59,625          35,213          50,861           2,442         282,811
TN......................................          31,715          62,519          70,226          19,597          69,385             405         253,847
                                         ---------------------------------------------------------------------------------------------------------------
    Total...............................         280,232         478,211         418,485         243,685         281,574          17,203       1,708,390
--------------------------------------------------------------------------------------------------------------------------------------------------------
* From the Tennessee Regional Haze SIP, Appendix D, page D.3-5 and support table for Technical Support Document for CENRAP Emissions and Air Quality
  Modeling to Support Regional Haze State Implementation Plans, page 2-40, figure 2-4.

    From 2002 to 2018 NOX emissions are projected to
decrease in the region by 1,215,024 tpy or 41.4 percent in all. EGU
NOX anticipated decreases due to CAIR and the NOX
SIP Call are projected to be 198,150 tpy. However the largest source in
this region remains the motor vehicle sector, which is projected to
decrease 737,744 tpy. Even without EGU controls on NOX
emissions, total NOX emissions are projected to continually
decrease throughout the maintenance period.
    On July 6, 2010, EPA proposed the Transport Rule, which will
require significant reductions in sulfur dioxide and NOX
emissions that cross state boundaries. This proposed rule will
potentially form the basis for a final rule which replaces EPA's 2005
CAIR (North Carolina v. EPA, 550 F.3d 1176 (D.C. Cir., 2008)).
    These regional projections of emissions data have been prepared
through 2018. However, since motor vehicle and non-road emissions
continue to decrease long after a rule is adopted as the engine
population is gradually replaced by newer engines, it is reasonable to
expect that this projected decrease in regional NOX
emissions from mobile and non-road sources should continue through 2024
and assure that ozone in the Knoxville Area will continue to decline
throughout the 10-year maintenance period. Hence, we believe the
projected regional NOX reductions are adequate to assure
that the Knoxville Area will continue demonstrating maintenance
throughout the 10-year maintenance period.

Criteria (4)--The Knoxville Area Has a Fully Approved Maintenance Plan
Pursuant to Section 175A of the CAA

    In conjunction with its request to redesignate the Knoxville Area
to attainment for the 1997 8-hour ozone NAAQS, TDEC submitted a SIP
revision to provide for the maintenance of the 1997 8-hour ozone NAAQS
for at least 10 years after the effective date of redesignation to
attainment.
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. Eight years after the
redesignation, the State of Tennessee must submit a revised maintenance
plan, which demonstrates that attainment will continue to be maintained
for the 10 years following the initial 10-year period. To address the
possibility of future NAAQS violations, the maintenance plan must
contain such contingency measures, with a schedule for implementation
as EPA deems necessary to assure prompt correction of any future 1997
8-hour ozone violations. Section 175A of the CAA sets forth the
elements of a maintenance plan for areas seeking redesignation from
nonattainment to attainment. The Calcagni Memorandum

provides additional guidance on the content of a maintenance plan. The
Calcagni Memorandum explains that an ozone maintenance plan should
address five requirements: the attainment emissions inventory,
maintenance demonstration, monitoring, verification of continued
attainment, and a contingency plan. As is discussed more fully below,
Tennessee's maintenance plan includes all the necessary components and
is approvable as part of the redesignation request.
b. Attainment Emissions Inventory
    The Knoxville Area attained the 1997 8-hour NAAQS with monitoring
data from 2007, 2008, and 2009, therefore Tennessee selected 2007 as
the attainment emission inventory year. The attainment inventory
identifies the level of emissions in the Area, which is sufficient to
attain the 1997 8-hour ozone NAAQS. Tennessee began development of the
attainment inventory by first developing a baseline emissions inventory
for the Knoxville Area. The year 2007 was chosen as the base year for
developing a comprehensive ozone precursor emissions inventory for
which projected emissions could be developed for 2010, 2013, 2016,
2020, and 2024. The projected inventory estimates emissions forward to
2024, which is beyond the 10-year interval required in section 175(A)
of the CAA. Non-road mobile emissions estimates were based on EPA's
NONROAD2008 model. On-road mobile source emissions were calculated
using EPA's MOBILE6.2 emission factors model. The 2007 VOC and
NOX emissions, as well as the emissions for other years, for
the Knoxville Area were developed consistent with EPA guidance, and are
summarized in Tables 5 and 6 in the following subsection.
c. Maintenance Demonstration
    The July 14, 2010, final submittal includes a maintenance plan for
the Knoxville Area. This demonstration:
    (i) Shows compliance and maintenance of the 1997 8-hour ozone NAAQS
by providing information to support the demonstration that current and
future emissions of VOC and NOX remain at or below
attainment inventory year 2007 emissions levels. The year 2007 was
chosen as the attainment inventory year because it is one of the most
recent three years (i.e., 2007, 2008, and 2009) for which the Knoxville
Area has clean air quality data for the 1997 8-hour ozone NAAQS.
    (ii) Uses 2007 as the attainment inventory year and includes future
emission inventory projections for 2010, 2013, 2016, 2020, and 2024.
    (iii) Identifies an ``out year,'' at least 10 years (and beyond)
after the time necessary for EPA to review and approve the maintenance
plan. Per 40 CFR part 93, NOx and VOC MVEBs were established for the
last year (2024) of the maintenance plan.
    (iv) Provides the following actual and projected emissions
inventories, in tpd for the Knoxville Area. See Tables 5 and 6.

                                                          Table 5--Knoxville Area VOC Emissions
                                                                   [Summer season tpd]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Summary of VOC emissions (tpd)
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Nonroad                                           Change from
                      Year                           Point         Area        Onroad     (excluding    Nonroad       Total        Safety        2007
                                                                                MLA)        (MLA)                     margin     (percent)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2007............................................         7.32        33.25        36.77        34.26         0.68       112.28  ...........  ...........
2010............................................         7.17        34.21        33.53        31.05         0.62       106.58         5.70         -5.1
2013............................................         7.37        35.23        30.29        26.47         0.52        99.88        12.40        -11.0
2016............................................         7.88        36.64        27.05        22.07         0.44        94.08        18.20        -16.2
2020............................................         8.64        38.40        22.72        18.04         0.35        88.15        24.13        -21.5
2024............................................         9.53        40.24        18.39        16.62         0.33        85.11        27.17        -24.2
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Emissions are for Anderson, Blount, Jefferson, Knox, Loudon, Sevier and onroad emissions for Cocke County.
MLA = Commercial Marine Vessels, Locomotives and Aircraft.

                                                          Table 6--Knoxville Area NOX Emissions
                                                                   [Summer season tpd]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Summary of NOX emissions (tpd)
---------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Nonroad                                           Change from
                      Year                           Point         Area        Onroad     (excluding    Nonroad       Total        Safety        2007
                                                                                MLA)        (MLA)                     margin     (percent)
--------------------------------------------------------------------------------------------------------------------------------------------------------
2007............................................        42.69         2.07        71.83        13.16         5.44       135.19
2010............................................        42.65         2.15        63.10        12.17         5.03       125.10        10.09         -7.5
2013............................................        42.94         2.29        54.36        10.51         4.34       114.44        20.75        -15.3
2016............................................        43.56         2.50        45.62         8.74         3.61       104.03        31.18        -23.0
2020............................................        44.30         2.60        33.96         7.21         2.98        91.05        44.14        -32.7
2024............................................        45.11         2.68        22.29         6.37         2.63        79.08        56.11        -41.5
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Emissions are for Anderson, Blount, Jefferson, Knox, Loudon, Sevier and onroad emissions for Cocke County.
MLA = Commercial Marine Vessels, Locomotives and Aircraft.

    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 has decided to allocate a portion of the available
safety margin to the Area's VOC and NOX MVEBs for 2024 for
the Knoxville Area and has calculated the safety margin in its
submittal. Specifically, 14.03 tpd of the available NOX
safety margin is allocated

to the 2024 MVEB, the remaining safety margin for NOX for
2024 is 42.08 tpd. Also, 6.8 tpd of the available VOC safety margin is
allocated to the 2024 MVEB, the remaining safety margin for VOC for
2024 is 20.37 tpd. See Tables 5 and 6, above. This allocation and the
resulting available safety margin for the Knoxville Area are discussed
further in section VII of this proposed rulemaking.
d. Monitoring Network
    There are currently nine monitors measuring ozone in the Knoxville
Area (see Table 1).\7\ TDEC and the Knox County Department of Air
Quality Management (DAQM) have committed, in the maintenance plan, to
continue operation of monitors in the Knoxville Area in compliance with
40 CFR part 58, and have addressed the requirement for monitoring.
---------------------------------------------------------------------------

    \7\ Of the nine air quality ozone monitors in the Knoxville
Area, the Clingman's Dome ozone monitoring site in Sevier County
does not meet siting criteria listing in 40 CFR part 58, and thus is
not appropriate to be used for the determination of attainment or
nonattainment for the ozone NAAQS.
---------------------------------------------------------------------------

e. Verification of Continued Attainment
    The State of Tennessee, through TDEC, and the Knox County DAQM have
the legal authority to enforce and implement the requirements of the
Knoxville Area 1997 8-Hour Ozone Maintenance plan. This includes the
authority to adopt, implement and enforce any subsequent emissions
control contingency measures determined to be necessary to correct
future ozone attainment problems.
    Both agencies will track the progress of the maintenance plan by
performing future reviews of triennial emission inventories for the
Knoxville Area using the latest emissions factors, models and
methodologies. For these periodic inventories, TDEC and Knox County
DAQM will review the assumptions made for the purpose of the
maintenance demonstration concerning projected growth of activity
levels. If any of these assumptions appear to have changed
substantially, the Knoxville Area will re-project emissions.
f. Contingency Plan
    The contingency plan provisions are designed to promptly correct a
violation of the NAAQS that occurs after redesignation. Section 175A of
the CAA requires that a maintenance plan include such contingency
measures as EPA deems necessary to assure that the 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 the state. 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).
    In the July 14, 2010, submittal, Tennessee affirms that all
programs instituted by the State and EPA will remain enforceable, and
that sources are prohibited from reducing emissions controls following
the redesignation of the Area. The contingency plan included in the
submittal includes a triggering mechanism to determine when contingency
measures are needed and a process of developing and implementing
appropriate control measures. The primary trigger will be a quality
assured/quality controlled (QA/QC) violating design value of the 1997
8-hour ozone NAAQS. In addition to the primary trigger indicated above,
Tennessee and the Knox County DAQM will monitor regional emissions
through the Consolidated Emissions Reporting Rule (CERR). If the CERR
results indicate that the projected emissions in this maintenance plan
are significantly less than the CERR reveals (greater than ten
percent), TDEC and Knox County DAQM will investigate the differences
and develop an appropriate strategy for addressing the differences. In
addition, if ambient monitoring data indicates that a violation of the
three-year design value may be imminent, TDEC and Knox County DAQM will
evaluate existing control measures to determine whether further
emission reduction measures should be implemented. If QA/QC data
indicates a violating design value for the 1997 8-hour ozone NAAQS,
then the triggering event will be the date of the design value
violation, and not the final QA/QC date. However, if initial monitoring
data indicates a possible violation but later QA/QC data indicates that
the NAAQS was not violated, then a triggering event will not have
occurred, and contingency measures will not be required.
    The contingency plan states that upon a measured violation of the
1997 8-hour ozone NAAQS in the Knoxville Area, TDEC and the Knox County
DAQM will complete sufficient analyses and provide those to the EPA. If
deemed necessary, contingency measures would be adopted and implemented
as expeditiously as possible, but no later than eighteen to twenty-four
months after a triggering event. The proposed schedule for these
actions would be as follows:
     Six months to identify appropriate contingency measures,
including identification of emission sources and appropriate control
technologies;
     Between three and six months to initiate a stakeholder
process; and
     Between nine and twelve months to implement the
contingency measures. This step would include the time required to
draft rules or SIP amendments, complete the rulemaking process, and
submit the final plans to EPA.

Tennessee will consider one or more of the following contingency
measures to re-attain the NAAQS:

     Implementation of diesel retrofit programs, including
incentives for performing retrofits.
     Reasonable Available Control Technology for NOX
sources in nonattainment counties.
     Programs or incentives to decrease motor vehicle use,
including employer-based programs, additional park and ride services,
enhanced transit service and encouragement of flexible work hours/
compressed work week/telecommuting.
     Trip reduction ordinances.
     Additional emissions reductions on stationary sources.
     Enhanced stationary source inspection to ensure that
emissions control equipment is functioning properly.
     Voluntary fuel programs, including incentives for
alternative fuels.
     Construction of high-occupancy vehicle (HOV) lanes, or
restriction of certain roads or lanes for HOV.
     Programs for new construction and major reconstruction of
bicycle and pedestrian facilities including shared use paths,
sidewalks, and bicycle lanes.
     Expand Air Quality Action Day activities/Clean Air
Partners public education outreach.
     Expansion of E-government services at State and local
levels.
     Additional enforcement or outreach on driver observance of
reduced speed limits.
     Land use/transportation polices.
     Promote non-motorized transportation.
     Promote tree-planting standards that favor trees with low
VOC biogenic emissions.
     Promote energy savings plans for local government.
     Gas can and lawnmower replacement programs.
     Seasonal open burning ban in nonattainment counties.

     Evaluate anti-idling rules and/or policy.
     Additional controls in upwind areas, if necessary.

Other control measures, not included in the above list, will be
considered if new control programs are deemed more advantageous for
this Area.
    EPA has concluded that the maintenance plan adequately addresses
the five basic components of a maintenance plan: attainment inventory,
maintenance demonstration, monitoring network, verification of
continued attainment, and a contingency plan. The maintenance plan SIP
revision submitted by the State of Tennessee for the Knoxville Area
meets the requirements of section 175A of the CAA and is approvable.

VII. What is EPA's analysis of Tennessee's proposed NOX and
VOC MVEBs for the Knoxville area?

    Under the CAA, states are required to submit, at various times,
control strategy SIPs and maintenance plans in ozone areas. These
control strategy SIPs (reasonable further progress 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, an MVEB is 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 VOC and
NOX for the entire Area. Tennessee is developing these
MVEBs, as required, for the last year of its maintenance plan, 2024.
The MVEBs reflect the total on-road emissions for 2024, plus an
allocation from the available VOC and NOX 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. These 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. The NOX and VOC MVEBs for
the Knoxville Area are defined in Table 7 below.

                Table 7--Knoxville Area VOC and NOX MVEBs
                           [Summer season tpd]
------------------------------------------------------------------------
                                                               2024
------------------------------------------------------------------------
NOX.....................................................           36.32
VOC.....................................................           25.19
------------------------------------------------------------------------

    As mentioned above, the Knoxville Area has chosen to allocate a
portion of the available safety margin to the 2024 NOX and
VOC MVEBs. This allocation is 14.03 tpd for NOX and 6.80 tpd
for VOC. Thus, the remaining safety margin in 2024 is 42.08 tpd for
NOX and 20.37 tpd for VOC.
    Through this rulemaking, EPA is proposing to approve the 2024 MVEBs
for VOC and NOX for the Knoxville Area because
EPA has determined that the Area maintains the 1997 8-hour ozone NAAQS
with the emissions at the levels of the budgets. Once the MVEBs for the
Knoxville Area (the subject of this rulemaking) are approved or found
adequate (whichever is done first), they must be used for future
conformity determinations.

VIII. What is the status of EPA's adequacy determination for the
proposed NOX and VOC MVEBs for 2024 for the Knoxville Area?

    Under section 176(c) of the CAA, new transportation projects, such
as the construction of new highways, must ``conform'' to (i.e., be
consistent with) the part of the 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. 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 a maintenance plan for that NAAQS.
    When reviewing submitted ``control strategy'' SIPs or maintenance
plans containing MVEBs, EPA may affirmatively find the MVEB contained
therein ``adequate'' for use in determining transportation conformity.
Once EPA affirmatively finds the submitted MVEB is adequate for
transportation conformity purposes, that MVEB must be used by state and
Federal agencies in determining whether proposed transportation
projects ``conform'' to the SIP as required by section 176(c) of the
CAA.
    EPA's substantive criteria for determining ``adequacy'' of an MVEB
are set out in 40 CFR 93.118(e)(4). The process for determining
``adequacy'' consists of three basic steps: public notification of a
SIP submission, a public comment period, and EPA's adequacy finding.
This process for determining the adequacy of submitted SIP MVEBs was
initially outlined in EPA's May 14, 1999, guidance, ``Conformity
Guidance on Implementation of March 2, 1999, Conformity Court
Decision.'' This guidance was finalized in the Transportation
Conformity Rule Amendments for the ``New 8-Hour Ozone and
PM2.5 National Ambient Air Quality Standards and
Miscellaneous Revisions for Existing Areas; Transportation Conformity
Rule Amendments--Response to Court Decision and Additional Rule
Change,'' on July 1, 2004 (69 FR 40004). Additional information on the
adequacy process for MVEBs is available in the proposed rule entitled,
``Transportation Conformity Rule Amendments: Response to Court Decision
and Additional Rule Changes,'' 68 FR 38974, 38984 (June 30, 2003).
    As discussed earlier, Tennessee's maintenance plan submission
includes VOC and NOX MVEBs for the Knoxville Area for 2024.
EPA reviewed both the VOCs and NOX MVEBs through the
adequacy process. The Tennessee SIP submission, including the Knoxville
Area VOC and NOX MVEBs was open for public comment on EPA's
adequacy Web site on June 15, 2010, found at: http://www.epa.gov/otaq/
stateresources/transconf/currsips.htm. The public comment period on
adequacy of the 2024 VOC and NOX MVEBs for Knoxville Area
closed on July 15, 2010. EPA did not receive any comments on the
adequacy of the

MVEBs, nor did EPA receive any requests for the SIP submittal.
    EPA intends to make its determination on the adequacy of the 2024
MVEBs for the Knoxville Area for transportation conformity purposes in
the near future by completing the adequacy process that was started on
June 15, 2010. After EPA finds the 2024 MVEBs adequate or approves
them, the new MVEBs for VOC and NOX must be used, for future
transportation conformity determinations. For required regional
emissions analysis years prior to 2024, the conformity test will be the
applicable interim emissions test applicable for the Area per 40 CFR
Part 93 (the transportation conformity rule). For required regional
emissions analysis years that involve 2024 or beyond, the applicable
budgets will be the new 2024 MVEBs. The 2024 MVEBs are defined in
section VII of this proposed rulemaking.

IX. What is EPA's analysis of the proposed 2007 base year emissions
inventory for the Knoxville Area?

    As discussed above, section 172(c)(3) of the CAA requires areas to
submit a base year emissions inventory. As part of Tennessee's request
to redesignate the Knoxville Area, the state submitted 2007 base year
emissions inventory to meet this requirement. Emissions contained in
the submittal cover the general source categories of point sources,
area sources, on-road mobile sources, and non-road mobile sources. All
emission summaries were accompanied by source-specific descriptions of
emission calculation procedures and sources of input data. On-road
mobile emissions were prepared using the MOBILE6.2 emissions model.
Tennessee's submittal documents 2007 emissions in the Knoxville Area in
units of tons per summer day. Table 8 below provides a summary of the
2007 summer day emissions of VOC and NOX for the Knoxville
Area.

    Table 8--Knoxville Area 2007 Summer Day Emissions for VOC and NOX
                           [Summer season tpd]
------------------------------------------------------------------------
              Source                       NOX                VOC
------------------------------------------------------------------------
Point Source Total................              42.69               7.32
Area Source Total.................               2.07              33.25
On-Road Mobile Source Total.......              71.83              36.77
Non-Road Mobile Source Total......              13.16              34.26
Non-Road Mobile Source Total......               5.44               0.68
                                   -------------------------------------
    Total for all Sources.........             135.19             112.28
------------------------------------------------------------------------

    EPA is proposing to approve this 2007 base year inventory as
meeting the section 172(c)(3) emissions inventory requirement.

X. Proposed Action on the Redesignation Request and Maintenance Plan
SIP Revision Including Approval of the 2024 NOX and VOC
MVEBs for the Knoxville Area

    EPA is proposing to make the determination that the Knoxville Area
has met the criteria for redesignation from nonattainment to attainment
for the 1997 8-hour ozone NAAQS. Further, EPA is proposing to approve
Tennessee's July 14, 2010, SIP submittal including the redesignation
request for the Knoxville Area. Additionally, EPA is proposing to
approve the baseline emissions inventory for the Knoxville Area for the
1997 8-hour ozone NAAQS. EPA believes that the redesignation request
and monitoring data demonstrate that the Knoxville Area has attained
the 1997 8-hour ozone NAAQS.
    EPA is also proposing to approve the maintenance plan for the
Knoxville Area included as part of the July 14, 2010, SIP revision as
meeting the requirements of section 175A of the CAA. The maintenance
plan includes NOX and VOC MVEBs for 2024. EPA is proposing
to approve the 2024 NOX and VOC MVEBs for the Knoxville Area
because the maintenance plan demonstrates that, in light of expected
emissions for all source categories, the Area will continue to maintain
the 1997 8-hour ozone NAAQS.
    Further as part of today's action, EPA is describing the status of
its adequacy determination for the 2024 NOX and VOC MVEBs,
in accordance with 40 CFR 93.118(f)(1). Within 24 months from the
effective date of EPA's adequacy finding for the MVEBs, or the
effective date for the final rule for this action, whichever is
earlier, the transportation partners will need to demonstrate
conformity to the new NOX and VOC MVEBs pursuant to 40 CFR
93.104(e).

XI. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the Act and applicable
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in
reviewing SIP submissions, EPA's role is to approve state choices,
provided that they meet the criteria of the CAA. Accordingly, this
proposed action merely approves state law as meeting Federal
requirements and does not impose additional requirements beyond those
imposed by state law. For that reason, this proposed action:
     Is not a ``significant regulatory action'' subject to
review by the Office of Management and Budget under Executive Order
12866 (58 FR 51735, October 4, 1993);
     Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have Federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
     Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the CAA; and
     Does not provide EPA with the discretionary authority to
address, as appropriate, disproportionate human health or environmental
effects, using

practicable and legally permissible methods, under Executive Order
12898 (59 FR 7629, February 16, 1994).
    In addition, this proposed rule does not have tribal implications
as specified by Executive Order 13175 (65 FR 67249, November 9, 2000),
because the SIP is not approved to apply in Indian country located in
the State, and EPA notes that it will not impose substantial direct
costs on tribal governments or preempt tribal law.

List of Subjects

40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental
relations, Nitrogen oxides, Ozone, Reporting and recordkeeping
requirements, and Volatile organic compounds.

40 CFR Part 81

    Environmental protection, Air pollution control, National parks,
Wilderness areas.

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

    Dated: September 28, 2010.
Gwendolyn Keyes Fleming,
Regional Administrator, Region 4.
[FR Doc. 2010-25291 Filed 10-6-10; 8:45 am]
BILLING CODE 6560-50-P