[Federal Register Volume 79, Number 218 (Wednesday, November 12, 2014)]
[Proposed Rules]
[Pages 67137-67154]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-26736]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R04-OAR-2014-0674; FRL-9919-17-Region 4]


Approval of Implementation Plans and Designation of Areas: 
Alabama; Redesignation of the Alabama Portion of the Chattanooga, 1997 
PM2.5 Nonattainment Area to Attainment

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule.

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SUMMARY: On April 23, 2013, the Alabama Department of Environmental 
Management (ADEM), submitted a request to redesignate the Alabama 
portion of the Chattanooga, TN-GA fine particulate matter 
(PM2.5) nonattainment area (hereafter referred to as the 
``Chattanooga TN-GA Area'' or ``Area'') to attainment for the 1997 
Annual PM2.5 National Ambient Air Quality Standards (NAAQS) 
and to approve a State Implementation Plan (SIP) revision containing a 
maintenance plan for the Alabama portion of the Chattanooga TN-GA Area. 
The Alabama portion of the Chattanooga TN-GA Area is comprised of a 
portion of Jackson County in Alabama. The Environmental Protection 
Agency (EPA) is proposing to approve the redesignation request and the 
related SIP revision, including the plan for maintaining attainment of 
the PM2.5 standard, for the Alabama portion of the 
Chattanooga TN-GA Area. EPA is also proposing to approve the on-road 
motor vehicle insignificance determination for direct PM2.5 
and nitrogen oxides (NOX) for the Alabama portion of the 
Chattanooga TN-GA Area. On September 14, 2012, Georgia submitted a 
request to redesignate the Georgia portion of the Chattanooga TN-GA 
Area, and EPA is expecting Tennessee to submit a request to redesignate 
the Tennessee portion of the Chattanooga TN-GA Area. EPA will be taking 
separate action on the requests from Georgia and Tennessee.

DATES: Comments must be received on or before December 3, 2014.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2014-0674 by one of the following methods:
    1. www.regulations.gov: Follow the on-line instructions for 
submitting comments.
    2. Email: R4-RDS@epa.gov.
    3. Fax: (404) 562-9019.
    4. Mail: EPA-R04-OAR-2014-0674, Regulatory Development Section, Air 
Planning Branch, Air, Pesticides and

[[Page 67138]]

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 to 4:30, excluding Federal holidays.
    Instructions: Direct your comments to Docket ID No. EPA-R04-OAR-
2014-0674. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
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 www.regulations.gov or 
email, information that you consider to be CBI or otherwise protected. 
The 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 email 
comment directly to EPA without going through www.regulations.gov, your 
email 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 
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 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 to 4:30, excluding 
Federal holidays.

FOR FURTHER INFORMATION CONTACT: Joydeb Majumder 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. Joydeb 
Majumder may be reached by phone at (404) 562-9121, or via electronic 
mail at majumder.joydeb@epa.gov.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. What are the actions EPA is proposing to take?
II. What is the background for EPA's proposed actions?
III. What are the criteria for redesignation?
IV. Why is EPA proposing these actions?
V. What is EPA's analysis of the request?
VI. What is the effect of January 4, 2013, D.C. Circuit decision 
regarding PM2.5 implementation under subpart 4?
VII. What is EPA's analysis of Alabama's proposed regional on-road 
motor vehicle insignificance determination for the Alabama portion 
of the Chattanooga TN-GA area?
VIII. What is the status of EPA's adequacy determination for the on-
road motor vehicle insignificance determination for the Alabama 
portion of the Chattanooga TN-GA area?
IX. Proposed Actions on the Redesignation Request and Maintenance 
Plan SIP Revision for the Alabama Portion of the Chattanooga TN-GA 
Area
X. What is the effect of EPA's proposed actions?
XI. Statutory and Executive Order Reviews

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

    In this action, EPA is proposing to make a determination that 
Chattanooga TN-GA Area is continuing to attain the 1997 Annual 
PM2.5 NAAQS \1\ and to take additional actions related to 
Alabama's request to redesignate the Alabama portion of the Area, which 
are summarized as follows and described in greater detail throughout 
this notice of proposed rulemaking. EPA proposes: (1) To redesignate 
the Alabama portion of the Chattanooga TN-GA Area to attainment for the 
1997 Annual PM2.5 NAAQS; and (2) to approve, under section 
175A of the Clean Air Act (CAA or Act), Alabama's 1997 Annual 
PM2.5 NAAQS maintenance plan for the Alabama portion of the 
Chattanooga TN-GA Area into the Alabama SIP.
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    \1\ On September 8, 2011, at 76 FR 55774, EPA determined that 
the Chattanooga TN-GA Area attained the 1997 PM2.5 NAAQS 
by its applicable attainment date of April 5, 2010, and that the 
Area was continuing to attain the PM2.5 standard with 
monitoring data that was currently available.
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    First, EPA proposes to determine that the Alabama portion of the 
Chattanooga TN-GA Area has met the requirements for redesignation under 
section 107(d)(3)(E) of the CAA. In this action, EPA is proposing to 
approve a request to change the legal designation of the portion of 
Jackson County, Alabama, that is located within the Chattanooga TN-GA 
Area from nonattainment to attainment for the 1997 Annual 
PM2.5 NAAQS.
    Second, EPA is proposing to approve Alabama's 1997 Annual 
PM2.5 NAAQS maintenance plan for the Alabama portion of the 
Chattanooga TN-GA Area (such approval being one of the CAA criteria for 
redesignation to attainment status). The maintenance plan is designed 
to help keep the Chattanooga TN-GA Area in attainment of the 1997 
Annual PM2.5 NAAQS through 2025. The maintenance plan that 
EPA is proposing to approve includes an insignificance determination 
for the on-road motor vehicle contribution of direct PM2.5 
and NOX to ambient PM2.5 levels in the Alabama 
portion of the Chattanooga TN-GA Area for transportation conformity 
purposes. EPA is proposing to approve the on-road motor vehicle 
insignificance determination into the Alabama SIP that is included as 
part of Alabama's maintenance plan for the 1997 Annual PM2.5 
NAAQS.
    Further, EPA proposes to make the determination that the 
Chattanooga TN-GA Area is continuing to attain the 1997 Annual 
PM2.5 NAAQS and that all other redesignation criteria have 
been met for the Alabama portion of the Chattanooga TN-GA Area. The 
bases for EPA's determination for the Area are discussed in greater 
detail below.
    EPA is also providing the public with an update on the status of 
EPA's adequacy process for the on-road motor vehicle insignificance 
determination for the Alabama portion of the Chattanooga

[[Page 67139]]

TN-GA Area. Please see section VIII of this proposed rulemaking for 
further explanation of this process and for details.
    Today's notice of proposed rulemaking is in response to Alabama's 
April 23, 2013, SIP revision, which requests redesignation of the 
Alabama portion of the Chattanooga TN-GA Area to attainment for the 
1997 Annual PM2.5 NAAQS and addresses 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?

    Fine particle pollution can be emitted directly or formed 
secondarily in the atmosphere. The main precursors of secondary 
PM2.5 are sulfur dioxide (SO2), NOX, 
ammonia, and volatile organic compounds (VOC). See 72 FR 20586, 20589 
(April 25, 2007). Sulfates are a type of secondary particle formed from 
SO2 emissions of power plants and industrial facilities. 
Nitrates, another common type of secondary particle, are formed from 
NOX emissions of power plants, automobiles, and other 
combustion sources.
    On July 18, 1997, EPA promulgated the first air quality standards 
for PM2.5. EPA promulgated an annual standard at a level of 
15 micrograms per cubic meter ([mu]g/m\3\), based on a 3-year average 
of annual mean PM2.5 concentrations. In the same rulemaking, 
EPA promulgated a 24-hour standard of 65 [mu]g/m\3\, based on a 3-year 
average of the 98th percentile of 24-hour concentrations. On October 
17, 2006, EPA retained the annual average NAAQS at 15 [mu]g/m\3\ but 
revised the 24-hour NAAQS to 35 [mu]g/m\3\, based again on the 3-year 
average of the 98th percentile of 24-hour concentrations.\2\ See 71 FR 
61144. Under EPA regulations at 40 CFR part 50, the primary and 
secondary 1997 Annual PM2.5 NAAQS are attained when the 
annual arithmetic mean concentration, as determined in accordance with 
40 CFR part 50, Appendix N, is less than or equal to 15.0 [mu]g/m\3\ at 
all relevant monitoring sites in the subject area over a 3-year period.
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    \2\ In response to legal challenges of the annual standard 
promulgated in 2006, the United States Court of Appeals for the 
District of Columbia Circuit (D.C. Cir.) remanded this NAAQS to EPA 
for further consideration. See American Farm Bureau Federation and 
National Pork Producers Council, et al. v. EPA, 559 F.3d 512 (D.C. 
Cir. 2009). However, given that the 1997 and 2006 Annual NAAQS are 
essentially identical, attainment of the 1997 Annual NAAQS would 
also indicate attainment of the remanded 2006 Annual NAAQS.
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    On January 5, 2005, and supplemented on April 14, 2005, EPA 
designated a portion of Jackson County, Alabama, in association with 
counties in Georgia and Tennessee in the Chattanooga TN-GA Area, as 
nonattainment for the 1997 PM2.5 NAAQS. See 70 FR 944 and 70 
FR 19844, respectively. On November 13, 2009, EPA promulgated 
designations for the 24-hour standard established in 2006, designating 
counties in the Chattanooga TN-GA Area as unclassifiable/attainment for 
the 2006 24-hour PM2.5 NAAQS. See 74 FR 58688. That action 
also clarified that the Alabama portion of the Chattanooga TN-GA Area 
was classified unclassifiable/attainment for the 1997 24-hour 
PM2.5 NAAQS promulgated. EPA did not promulgate designations 
for the annual PM2.5 NAAQS promulgated in 2006 since that 
NAAQS was essentially identical to the 1997 annual PM2.5 
NAAQS. Therefore, the Alabama portion of the Chattanooga TN-GA Area is 
designated nonattainment for the annual PM2.5 NAAQS 
promulgated in 1997, and today's action only addresses this 
designation.
    All 1997 PM2.5 NAAQS areas were designated under subpart 
1 of title I, part D, of the CAA. Subpart 1 contains the general 
requirements for nonattainment areas for any pollutant governed by a 
NAAQS and is less prescriptive than the other subparts of title I, part 
D. On April 25, 2007, EPA promulgated its PM2.5 
Implementation Rule, codified at 40 CFR part 51, subpart Z, in which 
the Agency provided guidance for state and tribal plans to implement 
the 1997 PM2.5 NAAQS. See 72 FR 20664. That rule, at 40 CFR 
51.1004(c), specifies some of the regulatory results of attaining the 
NAAQS, as discussed below. The United States Court of Appeals for the 
District of Columbia Circuit (D.C. Circuit) remanded the Clean Air Fine 
Particle Implementation Rule and the final rule entitled 
``Implementation of the New Source Review (NSR) Program for Particulate 
Matter Less than 2.5 Micrometers (PM2.5)'' final rule (73 FR 
28321, May 16, 2008) (collectively, ``1997 PM2.5 
Implementation Rule'') to EPA on January 4, 2013, in Natural Resources 
Defense Council v. EPA, 706 F.3d 428 (D.C. Cir. 2013). The court found 
that EPA erred in implementing the 1997 PM2.5 NAAQS pursuant 
to the general implementation provisions of subpart 1 of Part D of 
Title I of the CAA, rather than the particulate matter-specific 
provisions of subpart 4 of part D of title I. The effect of the court's 
ruling on this proposed redesignation action is discussed in detail in 
Section VI of this notice.
    The 3-year ambient air quality data for 2007-2009 indicated no 
violations of the 1997 Annual PM2.5 NAAQS for the 
Chattanooga TN-GA Area. As a result, on April 23, 2013, Alabama 
requested redesignation of the Alabama portion of the Chattanooga TN-GA 
Area to attainment for the 1997 Annual PM2.5 NAAQS. The 
redesignation request includes three years of complete, quality-assured 
ambient air quality data for the 1997 Annual PM2.5 NAAQS for 
2007-2009, indicating that this NAAQS had been achieved for the entire 
Chattanooga TN-GA 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 Chattanooga TN-GA Area's 
design value, based on data from 2007 through 2009, is below 15.0 
[mu]g/m\3\, which demonstrates attainment of the standards. While 
annual PM2.5 concentrations are dependent on a variety of 
conditions, the overall improvement in annual PM2.5 
concentrations in the Chattanooga TN-GA Area can be attributed to the 
reduction of pollutant emissions, as will be discussed in more detail 
in section V of this proposed rulemaking.
    The D.C. Circuit and the United States Supreme Court have issued a 
number of decisions and orders regarding the status of EPA's regional 
trading programs for transported air pollution, CAIR and CSAPR, that 
impact this proposed redesignation action. The effect of those court 
actions on this rulemaking is discussed in detail in Section V of this 
notice.

III. What are the criteria for redesignation?

    The CAA provides the requirements for redesignating a nonattainment 
area to attainment. Specifically, section 107(d)(3)(E) of the CAA 
allows for redesignation provided the following criteria are met: (1) 
The Administrator determines that the area has attained the applicable 
NAAQS; (2) the Administrator has fully approved the applicable 
implementation plan for the area under section 110(k); (3) the 
Administrator determines that the improvement in air quality is due to 
permanent and enforceable reductions in emissions resulting from 
implementation of the applicable SIP and applicable federal air 
pollutant control regulations and other permanent and enforceable 
reductions; (4) the Administrator has fully approved a maintenance plan 
for the area as

[[Page 67140]]

meeting the requirements of section 175A; and (5) the state containing 
such area has met all requirements applicable to the area under section 
110 and part D of title I of the CAA.
    EPA has provided guidance on redesignation in the General Preamble 
for the Implementation of title I of the CAA Amendments of 1990 (April 
16, 1992 (57 FR 13498) and supplemented on April 28, 1992 (57 FR 
18070)) and has provided further guidance on processing redesignation 
requests in the following documents:
    1. ``Procedures for Processing Requests to Redesignate Areas to 
Attainment,'' Memorandum from John Calcagni, Director, Air Quality 
Management Division, September 4, 1992 (hereafter referred to as the 
``Calcagni Memorandum'');
    2. ``State Implementation Plan (SIP) Actions Submitted in Response 
to Clean Air Act (CAA) Deadlines,'' Memorandum from John Calcagni, 
Director, Air Quality Management Division, October 28, 1992; and
    3. ``Part D New Source Review (Part D NSR) Requirements for Areas 
Requesting Redesignation to Attainment,'' Memorandum from Mary D. 
Nichols, Assistant Administrator for Air and Radiation, October 14, 
1994.

IV. Why is EPA proposing these actions?

    On April 23, 2013, ADEM requested the redesignation of the Alabama 
portion of the Chattanooga TN-GA Area to attainment for the 1997 Annual 
PM2.5 NAAQS. The Chattanooga TN-GA Area has attained the 
1997 Annual PM2.5 NAAQS, and EPA's preliminary evaluation 
indicates that the Alabama portion of the Chattanooga TN-GA Area 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 announcing the status of its adequacy 
determination for the insignificance determinations for both 
NOX and direct PM2.5 for the Alabama portion of 
the Chattanooga TN-GA Area. Additionally, EPA is also approving the 
insignificance determinations for both NOX and direct 
PM2.5 that were included in Alabama's maintenance plan.

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

    As stated above, in accordance with the CAA, EPA proposes in 
today's action to: (1) Redesignate the Alabama portion of the 
Chattanooga TN-GA Area to attainment for the 1997 Annual 
PM2.5 NAAQS; and (2) approve, into the Alabama SIP, the 1997 
Annual PM2.5 NAAQS maintenance plan, including the mobile 
source emissions insignificance determination under transportation 
conformity, for the Alabama portion of the Chattanooga TN-GA Area. 
Further, EPA proposes to make the determination that the Chattanooga 
TN-GA Area continues to attain the 1997 Annual PM2.5 NAAQS 
and that all other redesignation criteria have been met for the Alabama 
portion of the Chattanooga TN-GA Area. The five redesignation criteria 
provided under CAA section 107(d)(3)(E) are discussed in greater detail 
for the Area in the following paragraphs of this section.
    Criteria (1)--The Chattanooga TN-GA Area has attained the 1997 
Annual PM2.5 NAAQS.
    For redesignating a nonattainment area to attainment, the CAA 
requires EPA to determine that the area has attained the applicable 
NAAQS (CAA section 107(d)(3)(E)(i)). EPA is proposing to determine that 
the Chattanooga TN-GA Area continues to attain the 1997 Annual 
PM2.5 NAAQS since the May 31, 2011, attainment 
determination. See 76 FR 31239. For PM2.5, an area may be 
considered to be attaining the 1997 Annual PM2.5 NAAQS if it 
meets the 1997 Annual PM2.5 NAAQS, as determined in 
accordance with 40 CFR 50.13 and Appendix N of part 50, based on three 
complete, consecutive calendar years of quality-assured air quality 
monitoring data. To attain these NAAQS, the 3-year average of the 
annual arithmetic mean concentration, as determined in accordance with 
40 CFR part 50, Appendix N, must be less than or equal to 15.0 [mu]g/
m\3\ at all relevant monitoring sites in the subject area over a 3-year 
period. The relevant data must be collected and quality-assured in 
accordance with 40 CFR part 58 and recorded in the EPA Air Quality 
System (AQS) database. The monitors generally should have remained at 
the same location for the duration of the monitoring period required 
for demonstrating attainment.
    On May 31, 2011, EPA determined that the Chattanooga TN-GA Area was 
attaining the 1997 Annual PM2.5 NAAQS. See 76 FR 31239. For 
that action, EPA reviewed PM2.5 monitoring data from 
monitoring stations in the Chattanooga TN-GA Area for the 1997 Annual 
PM2.5 NAAQS for 2007-2009. These data had been quality-
assured by the respective state agencies and are recorded in AQS. In 
addition, on September 8, 2011, at 76 FR 55774, EPA finalized a 
determination that the Chattanooga TN-GA Area attained the 1997 Annual 
PM2.5 NAAQS by the applicable attainment date of April 5, 
2010. As summarized in Table 1, below, the 3-year averages of annual 
arithmetic mean concentrations (i.e., design values) for the years 2009 
through 2013 for the Chattanooga TN-GA Area are below the 1997 Annual 
PM2.5 NAAQS.

                    Table 1--Design Value Concentrations for the Chattanooga TN-GA Area for the 1997 Annual PM2.5 NAAQS ([mu]g/m\3\)
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                                                                                                       3-year design values
             Location                      County             Site ID    -------------------------------------------------------------------------------
                                                                             2007-2009       2008-2010       2009-2011       2010-2012       2011-2013
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Rossville--Maple St., Georgia.....  Walker County,             132950002          * 12.3            10.6            10.1            10.0            10.5
                                     Georgia.
Siskin Drive/UTC, Tennessee.......  Hamilton County,           470654002            12.9            11.6            11.1            10.9            10.0
                                     Tennessee.
Maxwell Road/East Ridge, Tennessee  Hamilton County,           470650031            12.7            11.7            11.2            11.1            10.1
                                     Tennessee.
Soddy-Daisy High School, Tennessee  Hamilton County,           470651011            11.8            11.4            11.0            11.2             9.8
                                     Tennessee.
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* Values subject to data substitution (76 FR 15895)


[[Page 67141]]

    As discussed above, the design value for an area is the highest 3-
year average of annual mean concentrations recorded at any monitor in 
the Area. Therefore, the 3-year design value for the period on which 
Alabama based its redesignation request (2007-2009) for the Chattanooga 
TN-GA Area is 12.9 [mu]g/m\3\, which is below the 1997 Annual 
PM2.5 NAAQS. Additional details can be found in EPA's final 
clean data determination for the Chattanooga TN-GA Area. See 76 FR 
31239 (May 31, 2011). EPA has reviewed more recent data which indicate 
that the Chattanooga TN-GA Area continues to attain the 1997 Annual 
PM2.5 NAAQS beyond the submitted 3-year attainment period of 
2007-2009. If the Area does not continue to attain before EPA finalizes 
the redesignation, EPA will not go forward with the redesignation. As 
discussed in more detail below, the four PM2.5 monitors in 
the Area will continue to operate in accordance with 40 CFR part 58 
unless a change is approved by EPA.
    Criteria (5)--Alabama has met all Applicable Requirements under 
Section 110 and part D of the CAA; and Criteria (2)--Alabama has a 
fully approved SIP under section 110(k) for the Alabama Portion of the 
Chattanooga TN-GA Area.
    For redesignating a nonattainment area to attainment, the CAA 
requires EPA to determine that the state has met all applicable 
requirements under section 110 and part D of title I of the CAA (CAA 
section 107(d)(3)(E)(v)) and that the state has a fully approved SIP 
under section 110(k) for the area (CAA section 107(d)(3)(E)(ii)). EPA 
proposes to find that Alabama has met all applicable SIP requirements 
for the Alabama portion of the Chattanooga TN-GA Area under section 110 
of the CAA (general SIP requirements) for purposes of redesignation. 
Additionally, EPA proposes to find that the Alabama SIP satisfies the 
criterion that it meets applicable SIP requirements for purposes of 
redesignation under part D of title I of the CAA (requirements specific 
to 1997 Annual PM2.5 nonattainment areas) in accordance with 
section 107(d)(3)(E)(v). Further, EPA proposes to determine that the 
SIP is fully approved with respect to all requirements applicable for 
purposes of redesignation in accordance with section 107(d)(3)(E)(ii). 
In making these determinations, EPA ascertained which requirements are 
applicable to the Area and, if applicable, that they are fully approved 
under section 110(k). SIPs must be fully approved only with respect to 
requirements that were applicable prior to submittal of the complete 
redesignation request.
    a. The Alabama portion of the Chattanooga TN-GA Area has met all 
applicable requirements under section 110 and part D of the CAA.
    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 (New Source Review (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 interstate 
transport of air pollutants. The section 110(a)(2)(D) requirements for 
a state are not linked with a particular nonattainment area's 
designation and classification in that state. EPA believes that the 
requirements linked with a particular nonattainment area's designation 
and classifications are the relevant measures to evaluate in reviewing 
a redesignation request. The transport SIP submittal requirements, 
where applicable, continue to apply to a state regardless of the 
designation of any one particular area in the state. Thus, EPA does not 
believe that the CAA's interstate transport requirements should be 
construed to be applicable requirements for purposes of redesignation.
    In addition, EPA believes other section 110 elements that are 
neither connected with nonattainment plan submissions nor linked with 
an area's attainment status are not applicable requirements for 
purposes of redesignation. The area will still be subject to these 
requirements after the area is redesignated. The section 110 and part D 
requirements which are linked with a particular area's designation and 
classification are the relevant measures to evaluate in reviewing a 
redesignation request. This approach is consistent with EPA's existing 
policy on applicability (i.e., for redesignations) of conformity and 
oxygenated fuels requirements, as well as with section 184 ozone 
transport requirements. See Reading, Pennsylvania, proposed and final 
rulemakings (61 FR 53174-53176, October 10, 1996), (62 FR 24826, May 7, 
1997); Cleveland-Akron-Loraine, Ohio, final rulemaking (61 FR 20458, 
May 7, 1996); and Tampa, Florida, final rulemaking at (60 FR 62748, 
December 7, 1995). See also the discussion on this issue in the 
Cincinnati, Ohio, redesignation (65 FR 37890, June 19, 2000), and in 
the Pittsburgh, Pennsylvania, redesignation (66 FR 50399, October 19, 
2001).
    On October 1, 2012, April 12, 2013, and May 7, 2014, EPA approved 
all infrastructure SIP elements required under section 110(a)(2) for 
the 1997 Annual PM2.5 NAAQS with the exception of the 
section 110(a)(2)(E)(ii) element that requires the State to comply with 
section 128 of the CAA. See 77 FR 59755 (October 1, 2012), 77 FR 62452 
(October 15, 2012), 78 FR 21841 (April 12, 2013), and 79 FR 26143 (May 
7, 2014). These requirements are, however, statewide requirements that 
are not linked to the PM2.5 nonattainment status of the 
Area. As stated above, EPA believes that section 110 elements not 
linked to an area's nonattainment status are not applicable for 
purposes of redesignation. Therefore, EPA believes it has approved all 
SIP elements under section 110 that must be approved as a prerequisite 
for the redesignation to attainment of the Alabama portion of the 
Chattanooga TN-GA Area.
    Title I, Part D, subpart 1 applicable SIP requirements. EPA 
proposes to determine that the Alabama SIP meets the applicable SIP 
requirements for the Alabama portion of the Chattanooga TN-GA Area for 
purposes of redesignation under part D of the CAA. Subpart 1 of part D, 
found in sections 172-176 of the CAA, sets forth the basic 
nonattainment requirements applicable to all nonattainment areas. All 
areas that were designated nonattainment for the 1997 Annual 
PM2.5 NAAQS were designated under subpart 1 of the CAA. For 
purposes of evaluating this redesignation request, the applicable part 
D, subpart 1 SIP requirements for all nonattainment areas are contained 
in sections 172(c)(1)-(9) and in section

[[Page 67142]]

176. A thorough discussion of the requirements contained in section 172 
can be found in the General Preamble for Implementation of title I. See 
57 FR 13498 (April 16, 1992). Section VI of this proposed rulemaking 
notice discusses the relationship between this proposed redesignation 
action and subpart 4 of Part D.
    Subpart 1 Section 172 Requirements. 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 NAAQS. 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. Under section 172, 
states with nonattainment areas must submit plans providing for timely 
attainment and meeting a variety of other requirements.
    EPA's longstanding interpretation of the nonattainment planning 
requirements of section 172 is that once an area is attaining the 
NAAQS, those requirements are not ``applicable'' for purposes of CAA 
section 107(d)(3)(E)(ii) and therefore need not be approved into the 
SIP before EPA can redesignate the area. In the 1992 General Preamble 
for Implementation of Title I, EPA set forth its interpretation of 
applicable requirements for purposes of evaluating redesignation 
requests when an area is attaining a standard. See 57 FR 13498, 13564 
(April 16, 1992). EPA noted that the requirements for reasonable 
further progress and other measures designed to provide for attainment 
do not apply in evaluating redesignation requests because those 
nonattainment planning requirements ``have no meaning'' for an area 
that has already attained the standard. Id. This interpretation was 
also set forth in the Calcagni Memorandum. EPA's understanding of 
section 172 also forms the basis of its Clean Data Policy, which was 
articulated with regard to PM2.5 in 40 CFR 51.1004(c), and 
suspends a state's obligation to submit most of the attainment planning 
requirements that would otherwise apply, including an attainment 
demonstration and planning SIPs to provide for reasonable further 
progress (RFP), RACM, and contingency measures under section 
172(c)(9).\3\ Courts have upheld EPA's interpretation of section 
172(c)(1)'s ``reasonably available'' control measures and control 
technology as meaning only those controls that advance attainment, 
which precludes the need to require additional measures where an area 
is already attaining. NRDC v. EPA, 571 F.3d 1245, 1252 (D.C. Cir. 
2009); Sierra Club v. EPA, 294 F.3d 155, 162 (D.C. Cir. 2002); Sierra 
Club v. EPA, 314 F.3d 735, 744 (5th Cir. 2002).
---------------------------------------------------------------------------

    \3\ This regulation was promulgated as part of the 1997 
PM2.5 NAAQS implementation rule that was subsequently 
challenged and remanded in NRDC v. EPA, 706 F.3d 428 (D.C. Cir. 
2013), as discussed in Section VI of this notice. However, the Clean 
Data Policy portion of the implementation rule was not at issue in 
that case.
---------------------------------------------------------------------------

    Therefore, because attainment has been reached in the Chattanooga 
TN-GA Area, no additional measures are needed to provide for 
attainment, and section 172(c)(1) requirements for an attainment 
demonstration and RACM are no longer considered to be applicable for 
purposes of redesignation as long as the Area continues to attain the 
standard until redesignation. Section 172(c)(2) requirement that 
nonattainment plans contain provisions promoting reasonable further 
progress toward attainment is also not relevant for purposes of 
redesignation because EPA has determined that the Chattanooga TN-GA 
Area has monitored attainment of the 1997 Annual PM2.5 
NAAQS. In addition, because the Chattanooga TN-GA Area has attained the 
1997 Annual PM2.5 NAAQS and is no longer subject to a RFP 
requirement, the requirement to submit the section 172(c)(9) 
contingency measures is not applicable for purposes of redesignation. 
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)(3) requires submission approval of a comprehensive, 
accurate, and current inventory of actual emissions. On February 8, 
2012, EPA approved Alabama's 2002 base-year emissions inventory for the 
Alabama Portion of the Chattanooga TN-GA Area as part of the SIP 
revision submitted by ADEM to provide for attainment of the 1997 
PM2.5 NAAQS in the Area. See 77 FR 6467.
    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.'' Alabama has demonstrated that the 
Alabama portion of the Chattanooga TN-GA Area will be able to maintain 
the NAAQS without part D NSR in effect, and therefore, Alabama need not 
have fully approved part D NSR programs prior to approval of the 
redesignation request. Alabama's PSD program will become effective in 
the Alabama portion of the Chattanooga TN-GA Area upon redesignation to 
attainment.
    Section 172(c)(7) requires the SIP to meet the applicable 
provisions of section 110(a)(2). As noted above, EPA believes the 
Alabama SIP meets the requirements of section 110(a)(2) applicable for 
purposes of redesignation.
    176 Conformity Requirements. Section 176(c) of the CAA requires 
states to establish criteria and procedures to ensure that federally-
supported or funded projects conform to the air quality planning goals 
in the applicable SIP. The requirement to determine conformity applies 
to transportation plans, programs, and projects that are developed, 
funded, or approved under title 23 of the United States Code (U.S.C.) 
and the Federal Transit Act (transportation conformity) as well as to 
all other federally-supported or funded projects (general conformity). 
State transportation conformity SIP revisions must be consistent with 
federal conformity regulations relating to consultation, enforcement, 
and enforceability that EPA promulgated pursuant to its authority under 
the CAA.
    EPA believes that it is reasonable to interpret the conformity SIP 
requirements \4\ as not applying for purposes of evaluating the 
redesignation request under section 107(d) because state conformity 
rules are still required after redesignation and federal conformity 
rules apply where state rules have not been approved. See Wall v.

[[Page 67143]]

EPA, 265 F.3d 426 (upholding this interpretation) (6th Cir. 2001); See 
60 FR 62748 (December 7, 1995).
---------------------------------------------------------------------------

    \4\ 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.
---------------------------------------------------------------------------

    Thus, for the reasons discussed above, the Alabama portion of the 
Chattanooga TN-GA Area has satisfied all applicable requirements for 
purposes of redesignation under section 110 and part D of the CAA.
    b. The Alabama portion of the Chattanooga TN-GA Area has a fully 
approved applicable SIP under section 110(k) of the CAA.
    EPA has fully approved the applicable Alabama SIP for the Alabama 
portion of the Chattanooga TN-GA Area for the 1997 Annual 
PM2.5 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 (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, Alabama has adopted and submitted, and EPA 
has fully approved at various times, provisions addressing the various 
SIP elements applicable for the 1997 Annual PM2.5 NAAQS in 
the Alabama portion of the Chattanooga TN-GA Area (e.g., 77 FR 59755 
(October 1, 2012)). 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.
    Criteria (3)--The air quality improvement in the Chattanooga TN-GA 
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.
    For redesignating a nonattainment area to attainment, the CAA 
requires EPA to determine that the air quality improvement in the area 
is due to permanent and enforceable reductions in emissions resulting 
from implementation of the SIP and applicable Federal air pollution 
control regulations and other permanent and enforceable reductions (CAA 
section 107(d)(3)(E)(iii)). EPA believes that Alabama has demonstrated 
that the observed air quality improvement in the Chattanooga TN-GA Area 
is due to permanent and enforceable reductions in emissions resulting 
from implementation of the SIP and Federal measures.
    Fine particulate matter, or PM2.5, refers to airborne 
particles less than or equal to 2.5 micrometers in diameter. Although 
treated as a single pollutant, fine particles come from many different 
sources and are composed of many different compounds. In the 
Chattanooga TN-GA Area, one of the largest components of 
PM2.5 is sulfate, which is formed through various chemical 
reactions from the precursor SO2. The other major component 
of PM2.5 is organic carbon, which originates predominantly 
from biogenic emission sources. Nitrate, which is formed from the 
precursor NOX, is also a component of PM2.5. 
Crustal materials from windblown dust and elemental carbon from 
combustion sources are less significant contributors to total 
PM2.5. VOCs, also precursors for PM, are emitted from a 
variety of sources, including motor vehicles, chemical plants, 
refineries, factories, consumer and commercial products, and other 
industrial sources. VOCs also are emitted by natural sources such as 
vegetation.
    Federal measures enacted in recent years have resulted in permanent 
emission reductions in particulate matter and its precursors. Most of 
these emission reductions are enforceable through regulations. The 
Federal measures that have been implemented include:
    Tier 2 vehicle standards and low-sulfur gasoline. In addition to 
requiring NOX controls, the Tier 2 rule reduced the 
allowable sulfur content of gasoline to 30 parts per million (ppm) 
starting in January of 2006. Most gasoline sold prior to this had a 
sulfur content of approximately 300 ppm.
    Heavy-duty gasoline and diesel highway vehicle standards & Ultra 
Low-Sulfur Diesel Rule. On October 6, 2000, the U.S. EPA promulgated a 
rule to reduce NOX and VOC emissions from heavy-duty 
gasoline and diesel highway vehicles that began to take effect in 2004. 
See 65 FR 59896. A second phase of standards and testing procedures 
began in 2007 to reduce particulate matter from heavy-duty highway 
engines, and reduce highway diesel fuel sulfur content to 15 ppm since 
the sulfur in fuel damages high efficiency catalytic exhaust emission 
control devices. The total program should achieve a 90 percent 
reduction PM emissions and a 95 percent reduction in NOX 
emission for new engines using low-sulfur diesel, compared to existing 
engines using higher-content sulfur diesel.
    Non-road, large spark-ignition engines and recreational engines 
standards. The non-road spark-ignition and recreational engine 
standards, effective in July 2003, regulate NOX, 
hydrocarbons, and carbon monoxide from groups of previously unregulated 
non-road engines. These engine standards apply to large spark-ignition 
engines (e.g., forklifts and airport ground service equipment), 
recreational vehicles (e.g., off-highway motorcycles and all-terrain-
vehicles), and recreational marine diesel engines sold in the United 
States and imported after the effective date of these standards.
    When all of the non-road spark-ignition and recreational engine 
standards are fully implemented, an overall 72 percent reduction in 
hydrocarbons, 80 percent reduction in NOX, and 56 percent 
reduction in carbon monoxide emissions are expected by 2020. These 
controls will help reduce ambient concentrations of ozone, carbon 
monoxide, and fine particulate matter.
    Large non-road diesel engine standards. Promulgated in 2004, this 
rule is being phased in between 2008 and 2014. This rule will reduce 
sulfur content in non-road diesel fuel and, when fully implemented, 
will reduce NOX and direct PM2.5 emissions by 
over 90 percent from these engines.
    Reciprocating Internal Combustion Engine standard. Initially 
promulgated in 2010, this rule regulates emissions of air toxics from 
existing diesel powered stationary reciprocating internal combustion 
engines that meet specific site rating, age, and size criteria. With 
all of the reciprocating internal combustion engine standards fully 
implemented in 2013, EPA estimates that PM2.5 emissions from 
these engines have been reduced by approximately 2,800 tons per year 
(tpy).
    Category 3 Marine Diesel Engine standard. Promulgated in 2010, this 
rule establishes more stringent exhaust emission standards for new 
large marine diesel engines with per cylinder displacement at or above 
30 liters (commonly referred to as Category 3 compression-ignition 
marine engines) as part of a coordinated strategy to address emissions 
from all ships that affect U.S. air quality. Near-term standards for 
newly built engines applied beginning in 2011, and long-term standards 
requiring an 80 percent reduction in NOX emissions will 
begin in 2016.
    NOX SIP Call. 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. Affected states were 
required to comply with Phase I of the SIP Call

[[Page 67144]]

beginning in 2004 and Phase II beginning in 2007. Emission reductions 
resulting from regulations developed in response to the NOX 
SIP Call are permanent and enforceable.
    CAIR and CSAPR. The Clean Air Interstate Rule (CAIR) was 
promulgated in 2005 and required 28 eastern states and the District of 
Columbia to significantly reduce emissions of SO2 and 
NOX from electric generating units (EGUs) in order to limit 
the interstate transport of these pollutants and the ozone and fine 
particulate matter they form in the atmosphere. 70 FR 25162 (May 12, 
2005). In 2008, the D.C. Circuit initially vacated CAIR, North Carolina 
v. EPA, 531 F.3d 896 (D.C. Cir. 2008), but ultimately remanded the rule 
to EPA without vacatur to preserve the environmental benefits provided 
by CAIR, North Carolina v. EPA, 550 F.3d 1176, 1178 (D.C. Cir. 2008). 
On August 8, 2011, acting on the Court's remand, EPA promulgated CSAPR, 
to address interstate transport of emissions and resulting secondary 
air pollutants and to replace CAIR (76 FR 48208).\5\ CSAPR requires 
substantial reductions of SO2 and NOX emissions 
from EGUs in 28 states in the Eastern United States. Implementation of 
the rule was scheduled to begin on January 1, 2012, when CSAPR's cap-
and-trade programs would have superseded the CAIR cap-and-trade 
programs. Numerous parties filed petitions for review of CSAPR, and on 
December 30, 2011, the D.C. Circuit issued an order staying CSAPR 
pending resolution of the petitions and directing EPA to continue to 
administer CAIR. EME Homer City Generation, L.P. v. EPA, No. 11-1302 
(D.C. Cir. Dec. 30, 2011), Order at 2.
---------------------------------------------------------------------------

    \5\ CAIR addressed the 1997 PM2.5 Annual standard and 
the 1997 8-hour ozone standard. CSAPR addresses contributions from 
upwind states to downwind nonattainment and maintenance of the 2006 
24-hour PM2.5 standard as well as the ozone and 
PM2.5 NAAQS addressed by CAIR.
---------------------------------------------------------------------------

    On August 21, 2012, the D.C. Circuit issued its ruling, vacating 
and remanding CSAPR to the Agency and once again ordering continued 
implementation of CAIR. EME Homer City Generation, L.P. v. EPA, 696 
F.3d 7, 38 (D.C. Cir. 2012). The D.C. Circuit subsequently denied EPA's 
petition for rehearing en banc. EME Homer City Generation, L.P. v. EPA, 
No. 11-1302, 2013 WL 656247 (D.C. Cir. Jan. 24, 2013), at *1. EPA and 
other parties then petitioned the Supreme Court for a writ of 
certiorari, and the Supreme Court granted the petitions on June 24, 
2013. EPA v. EME Homer City Generation, L.P., 133 S. Ct. 2857 (2013).
    On April 29, 2014, the Supreme Court vacated and reversed the D.C. 
Circuit's decision regarding CSAPR and remanded that decision to the 
D.C. Circuit to resolve remaining issues in accordance with its ruling. 
EPA v. EME Homer City Generation, L.P., 134 S. Ct. 1584 (2014). EPA 
filed a motion to lift the stay in light of the Supreme Court decision, 
and on October 23, 2014, the D.C. Circuit granted EPA's motion. EME 
Homer City Generation, L.P. v. EPA, Case No. 11-1302, Document No. 
1518738.
    EPA approved a modification to Alabama's SIP on October 1, 2007, 
that addressed the requirements of CAIR for the purpose of reducing 
SO2 and NOX emissions (see 72 FR 55659), and 
Alabama's SIP redesignation request lists CAIR/CSAPR as a control 
measure. CAIR was in place and getting emission reductions when the 
Chattanooga TN-GA Area began monitoring attainment of the 1997 Annual 
PM2.5 NAAQS. The quality-assured, certified monitoring data 
used to demonstrate the area's attainment of the 1997 Annual 
PM2.5 NAAQS by the April 5, 2010, attainment deadline was 
also impacted by CAIR. However, EPA conducted an air quality modeling 
analysis as part of the CSAPR rulemaking which demonstrates that the 
Chattanooga TN-GA Area would be able to maintain the 1997 Annual 
PM2.5 NAAQS even in the absence of either CAIR or CSAPR. See 
``Air Quality Modeling Final Rule Technical Support Document,'' App. B, 
B-39.\6\ This modeling is available in the docket for this proposed 
redesignation action. In addition, as noted above, the D.C. Circuit has 
lifted the stay of CSAPR. Therefore, to the extent that these transport 
rules impact attainment of the 1997 Annual PM2.5 NAAQS in 
the Chattanooga TN-GA Area, any emission reductions associated with 
CAIR that helped the Chattanooga TN-GA Area achieve attainment of the 
1997 Annual PM2.5 NAAQS are permanent and enforceable for 
purposes of redesignation under section 107(d)(3)(E)(iii) of the CAA 
because CSAPR requires similar or greater emission reductions from 
relevant upwind areas starting in 2015 and beyond.
---------------------------------------------------------------------------

    \6\ The air quality modeling analysis for the CSAPR rulemaking 
did not identify any of the four monitors in the Chattanooga TN-GA 
Area as receptors.
---------------------------------------------------------------------------

    Criteria (4) --The Alabama portion of the Chattanooga TN-GA Area 
has a fully approved maintenance plan pursuant to section 175A of the 
CAA.
    For redesignating a nonattainment area to attainment, the CAA 
requires EPA to determine that the area has a fully approved 
maintenance plan pursuant to section 175A of the CAA (CAA section 
107(d)(3)(E)(iv)). In conjunction with its request to redesignate the 
Alabama portion of the Chattanooga TN-GA Area to attainment for the 
1997 Annual PM2.5 NAAQS, ADEM submitted a SIP revision to 
provide for the maintenance of the 1997 Annual PM2.5 NAAQS 
for at least 10 years after the effective date of redesignation to 
attainment. EPA believes that this maintenance plan meets the 
requirements for approval under section 175A of the CAA.
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, ADEM 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, as EPA deems necessary, to assure prompt 
correction of any future 1997 Annual PM2.5 NAAQS violations. 
The Calcagni Memorandum provides further guidance on the content of a 
maintenance plan, explaining that a maintenance plan should address 
five requirements: the attainment emissions inventory, maintenance 
demonstration, monitoring, verification of continued attainment, and a 
contingency plan. As is discussed below, EPA finds that ADEM's 
maintenance plan includes all the necessary components and is thus 
proposing to approve it as a revision to the Alabama SIP.
b. CAA 175 Maintenance Plan Requirements
1. Attainment Emissions Inventory
    The Chattanooga TN-GA Area attained the 1997 Annual 
PM2.5 NAAQS based on monitoring data for the 3-year period 
from 2007-2009. ADEM has selected 2007 as the attainment emission 
inventory year. The attainment inventory identifies a level of 
emissions in the Area that is sufficient to attain the 1997 Annual 
PM2.5 NAAQS. ADEM began development of the attainment 
inventory by first generating a baseline emissions inventory for the 
Alabama portion of the Chattanooga TN-GA Area.

[[Page 67145]]

As noted above, the year 2007 was chosen as the base year for 
developing a comprehensive emissions inventory for direct 
PM2.5 and PM2.5 precursors SO2 and 
NOX. Emissions projections to support maintenance through 
2025 have been prepared for the years 2017 and 2025. The projected 
inventory included with the maintenance plan estimates emissions 
forward to 2025, which satisfies the 10-year interval required in 
section 175(A) of the CAA.
    The emissions inventories are composed of four major types of 
sources: point, area, on-road mobile, and non-road mobile. The 2007 
inventory, with the exception of on-road mobile emissions, was prepared 
for Alabama by the contractor for the Southeastern Modeling, Analysis, 
and Planning (SEMAP) project. Under the SEMAP project, emissions 
estimates are reported by county and source classification code. The 
SEMAP emissions inventories were developed using data from a number of 
sources, including state and local agencies and EPA's National 
Emissions Inventory (NEI). ADEM developed the 2007 inventory of on-road 
mobile emissions. The 2007 SO2, NOX, and 
PM2.5 emissions for the Alabama portion of the Chattanooga 
TN-GA Area, as well as the emissions for other years, were developed 
consistent with EPA guidance and are summarized in Tables 2 through 6 
of the following subsection discussing the maintenance demonstration.
2. Maintenance Demonstration
    The April 23, 2013, final submittal includes a maintenance plan for 
the Alabama portion of the Chattanooga TN-GA Area. This demonstration:
    (i) Shows compliance with and maintenance of the Annual 
PM2.5 standard by providing information to support the 
demonstration that current and future emissions of SO2 and 
NOX will remain below 2007 emission levels.
    (ii) Uses 2007 as the attainment year and includes future emission 
inventory projections for 2017 and 2025.
    (iii) Identifies an ``out year'' at least 10 years after EPA review 
and potential approval of the maintenance plan. ADEM submitted an 
insignificance determination for transportation conformity purposes for 
PM2.5 and NOX for the mobile source contribution 
for the Alabama portion of the Chattanooga TN-GA Area, per 40 CFR part 
93.
    (iv) Provides, as shown in Tables 2, 3, 4, 5, and 6 below, the 
actual and projected emissions inventories, in tpy, for the Alabama 
portion of the Chattanooga TN-GA Area.

   Table 2--Actual (2007) and Projected Point Source Emissions for the
              Alabama Portion of the Chattanooga TN-GA Area
                                 [Tons]
------------------------------------------------------------------------
              Pollutant                  2007        2017        2025
------------------------------------------------------------------------
SO2.................................   32,803.98   10,515.63   10,517.47
NOX.................................   18,591.83    3,468.44    3,607.05
PM2.5...............................      755.49      534.89      534.89
------------------------------------------------------------------------


 Table 3--Actual (2007) and Projected Non-Point Source Emissions for the
              Alabama Portion of the Chattanooga TN-GA Area
                                 [Tons]
------------------------------------------------------------------------
              Pollutant                  2007        2017        2025
------------------------------------------------------------------------
SO2.................................        0.25        0.25        0.24
NOX.................................        1.58        1.55        1.57
PM2.5...............................       27.11       28.08       29.17
------------------------------------------------------------------------


  Table 4--Actual (2007) and Projected On-Road Mobile Sources Emissions
          for the Alabama Portion of the Chattanooga TN-GA Area
                                 [Tons]
------------------------------------------------------------------------
              Pollutant                  2007        2017        2025
------------------------------------------------------------------------
SO2.................................        0.19        0.07        0.07
NOX.................................       23.00        9.00        6.00
PM2.5...............................        0.73        0.31        0.24
------------------------------------------------------------------------


  Table 5--Actual (2007) and Projected Non-Road Mobile Source Emissions
          for the Alabama Portion of the Chattanooga TN-GA Area
                                 [Tons]
------------------------------------------------------------------------
              Pollutant                  2007        2017        2025
------------------------------------------------------------------------
SO2.................................        0.91        0.15        0.15
NOX.................................       37.32       25.86       18.95
PM2.5...............................        2.05        1.01        0.63
------------------------------------------------------------------------


[[Page 67146]]


 Table 6--Actual (2007) and Projected Emissions for All Sectors for the
              Alabama Portion of the Chattanooga TN-GA Area
                                 [Tons]
------------------------------------------------------------------------
              Pollutant                  2007        2017        2025
------------------------------------------------------------------------
SO2.................................   32,805.33   10,516.10   10,517.93
NOX.................................   18,653.73    3,504.83    3,633.57
PM2.5...............................      785.38      564.29      564.93
------------------------------------------------------------------------

    As reflected in Table 6, future emissions of direct 
PM2.5 and the relevant precursors are expected to be below 
the ``attainment level'' emissions in 2007. In situations where local 
emissions are the primary contributor to nonattainment, such as the 
Chattanooga TN-GA Area, if the future projected emissions in the 
nonattainment area remain at or below the baseline emissions in the 
nonattainment area, then the ambient air quality standard should not be 
exceeded in the future. As explained below, EPA finds that the overall 
emission projections illustrate that the Chattanooga TN-GA Area is 
expected to continue to attain the 1997 PM2.5 NAAQS through 
2025.\7\
---------------------------------------------------------------------------

    \7\ Based on a limited review of data and emissions projections 
available to EPA from the Georgia and Tennessee portions of the 
Chattanooga TN-GA Area, EPA does not at this time believe that 
projected emissions from those portions of the Area present a 
maintenance problem for air quality in the Area as a whole.
---------------------------------------------------------------------------

    Emissions of SO2, NOx, and PM2.5 are 
projected to decline by 68 percent, 81 percent, and 28 percent, 
respectively, from 2007 to 2025. This is a reflection of the 
implementation of the majority of Federal controls during the first 
half of the maintenance period. The projected declines in emissions 
demonstrate that the 1997 Annual PM2.5 NAAQS will be 
maintained.
    A maintenance plan requires the state to show that projected future 
year emissions will not exceed the level of emissions which led the 
Area to attain the NAAQS. EPA agrees that Alabama's projected emissions 
demonstrate that the Chattanooga TN-GA Area will continue to attain for 
the duration of the maintenance plan.
3. Monitoring Network
    There is no monitor measuring ambient PM2.5 in the 
Alabama portion of the Chattanooga TN-GA Area. However, there are four 
monitors located in the Chattanooga TN-GA Area. Three monitors are 
located in Hamilton County, Tennessee, and one monitor is located in 
Walker County, Georgia. As noted in Alabama's maintenance plan, all 
four monitors will continue to operate in the Chattanooga TN-GA Area in 
compliance with 40 CFR part 58 unless a change is approved by EPA, and 
no plans are underway to discontinue operation, relocate, or otherwise 
affect the integrity of these monitors. EPA proposes to find that 
Alabama has thus addressed the requirement for monitoring.
4. Verification of Continued Attainment
    ADEM has the legal authority to enforce and implement the 
requirements of the Alabama portion of the Chattanooga TN-GA Area 
through the 1997 Annual PM2.5 maintenance plan. This 
includes the authority to adopt, implement, and enforce any subsequent 
emissions control contingency measures determined to be necessary to 
correct future PM2.5 attainment problems.
    ADEM will track the progress of the maintenance plan by performing 
future reviews of triennial emission inventories for the Alabama 
portion of the Chattanooga TN-GA Area as required in the Air Emissions 
Reporting Rule (AERR) and Consolidated Emissions Reporting Rule (CERR). 
For these periodic inventories, ADEM 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, then ADEM will re-project emissions for the 
Alabama portion of the Chattanooga TN-GA Area.
5. Contingency Measures in the Maintenance Plan.
    Section 175A of the CAA requires that a maintenance plan include 
such contingency measures as EPA deems necessary to assure that 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 ADEM. A state should 
also identify specific indicators to be used to determine when the 
contingency measures need to be implemented. The maintenance plan must 
include a requirement that a state will implement all measures with 
respect to control of the pollutant that were contained in the SIP 
before redesignation of the area to attainment in accordance with 
section 175A(d).
    The contingency plan included in the submittal includes a 
triggering mechanism to determine when contingency measures are needed 
and a process of developing and implementing appropriate control 
measures. ADEM will use actual ambient monitoring data to determine 
whether a trigger event has occurred and when contingency measures 
should be implemented. ADEM commits to adopt, within 18 months of 
certification of a violation of the Annual PM2.5 standard, 
one or more control measures as needed to re-attain the standard.
    In accordance with 40 CFR part 58, ambient fine particulate matter 
monitoring data that indicates a future violation of the 1997 Annual 
PM2.5 NAAQS will begin the process to implement these 
contingency measures. Also, in the event that the annual average 
PM2.5 concentrations in a year at any individual monitor in 
the Area records a reading of 15.0 [mu]g/m\3\ or higher, the State will 
evaluate existing control measures to determine whether any further 
emissions reduction measures should be implemented at that time.
    Several factors will be considered in determining the need for 
additional control measures in the event of a future year violation of 
the 1997 Annual PM2.5 standard. Depending on when such 
future year violation occurs, additional local and regional emissions 
reductions may still be expected from various regulatory programs not 
accounted for in the redesignation request. If a future year violation 
occurs, ADEM will consider the air quality impact of these various 
regulatory programs in determining the need for additional local 
reductions in emissions of direct PM2.5 and/or 
SO2.
    If deemed necessary, contingency measures will be selected from the 
following types of measures or from any other measures deemed 
appropriate and effective at the time the selection is made:
     Reasonably Available Control Measures (RACM) for sources 
of SO2 and PM2.5;

[[Page 67147]]

     Reasonably Available Control Technology (RACT) for point 
sources of SO2 and PM2.5;
     Expansion of RACM/RACT to area of transport within the 
State; and
     Additional SO2 and/or PM2.5 
reduction measures yet to be identified.
    Any resulting contingency measures will be based upon cost 
effectiveness, emission reduction potential, economic and social 
consideration, ease and timing of implementation, and other appropriate 
factors.
    A timeline of the development of PM2.5, and/or 
SO2 regulations or permit conditions follows. This schedule 
initiates with certification of ambient air quality monitoring data 
indicating a violation of the 1997 Annual PM2.5 NAAQS:

Table 7--Schedule for Permit Revisions or Rule Revisions for Contingency
                                Measures
------------------------------------------------------------------------
 
------------------------------------------------------------------------
1...........  Identify and quantify the emissions       3 months.
               reductions expected to result in the
               future from existing and future state
               and federal regulatory programs.
2...........  Use the best available air quality        6 months.
               modeling to evaluate the air quality
               improvement expected to result in
               Jackson County from the programs and
               emissions reductions identified in Step
               1 above.
3...........  Draft any needed permit conditions or     3 months.
               SIP regulations.
4...........  Complete rulemaking or permit revision    6 months.
               process and submit to EPA.
              Completion no later than................  18 months.
------------------------------------------------------------------------

    EPA has concluded that the maintenance plan adequately addresses 
the five basic components required: the attainment emissions inventory, 
maintenance demonstration, monitoring, verification of continued 
attainment, and a contingency plan. Therefore, the maintenance plan SIP 
revision submitted by ADEM for the Alabama portion of the Chattanooga 
TN-GA Area meets the requirements of section 175A of the CAA and EPA is 
proposing that Alabama's submission is approvable.

VI. What is the effect of the January 4, 2013, D.C. Circuit decision 
regarding PM2.5 implementation under subpart 4?

a. Background

    As discussed in Section I of this action, the D.C. Circuit remanded 
the 1997 PM2.5 Implementation Rule to EPA on January 4, 
2013, in Natural Resources Defense Council v. EPA, 706 F.3d 428. The 
court found that EPA erred in implementing the 1997 PM2.5 
NAAQS pursuant to the general implementation provisions of subpart 1 of 
part D of Title I of the CAA rather than the particulate matter-
specific provisions of subpart 4 of part D of Title I.

b. Proposal on This Issue

    In this portion of the proposed redesignation, EPA addresses the 
effect of the Court's January 4, 2013, ruling on the proposed 
redesignation. As explained below, EPA is proposing to determine that 
the Court's January 4, 2013, decision does not prevent EPA from 
redesignating the Alabama portion of the Chattanooga TN-GA Area to 
attainment. Even in light of the Court's decision, redesignation for 
this area is appropriate under the CAA and EPA's longstanding 
interpretations of the CAA's provisions regarding redesignation. EPA 
first explains its longstanding interpretation that requirements that 
are imposed, or that become due, after a complete redesignation request 
is submitted for an area that is attaining the standard, are not 
applicable for purposes of evaluating a redesignation request. Second, 
EPA then shows that, even if EPA applies the subpart 4 requirements to 
the Alabama portion of the Chattanooga TN-GA Area redesignation request 
and disregards the provisions of its 1997 PM2.5 
Implementation Rule recently remanded by the Court, the State's request 
for redesignation of the Alabama portion of the Chattanooga TN-GA Area 
still qualifies for approval. EPA's discussion takes into account the 
effect of the Court's ruling on the maintenance plan for the Alabama 
portion of the Chattanooga TN-GA Area, which EPA views as approvable 
when subpart 4 requirements are considered.

c. Applicable Requirements for the Purpose of Evaluating the 
Redesignation Request

    With respect to the 1997 PM2.5 Implementation Rule, the 
Court's January 4, 2013, ruling rejected EPA's reasons for implementing 
the PM2.5 NAAQS solely in accordance with the provisions of 
subpart 1 and remanded that matter to EPA to address implementation of 
the 1997 PM2.5 NAAQS under subpart 4 of part D of the CAA, 
in addition to subpart 1. For the purposes of evaluating Alabama's 
redesignation request for the Alabama portion of the Chattanooga TN-GA 
Area, to the extent that implementation under subpart 4 would impose 
additional requirements for areas designated nonattainment, EPA 
believes that those requirements are not ``applicable'' for the 
purposes of CAA section 107(d)(3)(E), and thus EPA is not required to 
consider subpart 4 requirements with respect to the redesignation of 
the Alabama portion of the Chattanooga TN-GA Area. Under its 
longstanding interpretation of the CAA, EPA has interpreted section 
107(d)(3)(E) to mean, as a threshold matter, that the part D provisions 
which are ``applicable'' and which must be approved in order for EPA to 
redesignate an area include only those which came due prior to a 
state's submittal of a complete redesignation request. See ``Procedures 
for Processing Requests to Redesignate Areas to Attainment,'' 
Memorandum from John Calcagni, Director, Air Quality Management 
Division, September 4, 1992 (Calcagni memorandum). See also ``State 
Implementation Plan (SIP) Requirements for Areas Submitting Requests 
for the plan and 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, Air and Radiation, September 17, 1993 (Shapiro 
memorandum); Final Redesignation of Detroit-Ann Arbor, (60 FR 12459, 
12465-66, March 7, 1995); Final Redesignation of St. Louis, Missouri, 
(68 FR 25418, 25424-27, May 12, 2003); Sierra Club v. EPA, 375 F.3d 
537, 541 (7th Cir. 2004) (upholding EPA's redesignation rulemaking 
applying this interpretation and expressly rejecting Sierra Club's view 
that the meaning of ``applicable'' under the statute is ``whatever 
should have been in the plan at the time of attainment rather than 
whatever actually was in already implemented or due at the time of 
attainment'').\8\ In this case, at the time that Alabama submitted its 
redesignation request on April 23, 2013,

[[Page 67148]]

requirements under subpart 4 were not due.
---------------------------------------------------------------------------

    \8\ 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. Section 175A(c) of the CAA.
---------------------------------------------------------------------------

    EPA's view that, for purposes of evaluating the Alabama portion of 
the Chattanooga TN-GA Area redesignation, the subpart 4 requirements 
were not due at the time the State submitted the redesignation request 
is in keeping with the EPA's interpretation of subpart 2 requirements 
for subpart 1 ozone areas redesignated subsequent to the D.C. Circuit's 
decision in South Coast Air Quality Mgmt. Dist. v. EPA, 472 F.3d 882 
(D.C. Cir. 2006). In South Coast, the Court found that EPA was not 
permitted to implement the 1997 8-hour ozone standard solely under 
subpart 1 and held that EPA was required under the statute to implement 
the standard under the ozone-specific requirements of subpart 2 as 
well. Subsequent to the South Coast decision, in evaluating and acting 
upon redesignation requests for the 1997 8-hour ozone standard that 
were submitted to EPA for areas under subpart 1, EPA applied its 
longstanding interpretation of the CAA that ``applicable 
requirements,'' for purposes of evaluating a redesignation, are those 
that had been due at the time the redesignation request was submitted. 
See, e.g., Proposed Redesignation of Manitowoc County and Door County 
Nonattainment Areas (75 FR 22047, 22050, April 27, 2010). In those 
actions, EPA therefore did not consider subpart 2 requirements to be 
``applicable'' for the purposes of evaluating whether the area should 
be redesignated under section 107(d)(3)(E).
    EPA's interpretation derives from the provisions of CAA Section 
107(d)(3)(E). Section 107(d)(3)(E)(v) states that, for an area to be 
redesignated, a state must meet ``all requirements `applicable' to the 
area under section 110 and part D.'' Section 107(d)(3)(E)(ii) provides 
that the EPA must have fully approved the ``applicable'' SIP for the 
area seeking redesignation. These two sections read together support 
EPA's interpretation of ``applicable'' as only those requirements that 
came due prior to submission of a complete redesignation request. 
First, holding states to an ongoing obligation to adopt new CAA 
requirements that arose after the state submitted its redesignation 
request, in order to be redesignated, would make it problematic or 
impossible for EPA to act on redesignation requests in accordance with 
the 18-month deadline Congress set for EPA action in section 
107(d)(3)(D). If ``applicable requirements'' were interpreted to be a 
continuing flow of requirements with no reasonable limitation, states, 
after submitting a redesignation request, would be forced continuously 
to make additional SIP submissions that in turn would require EPA to 
undertake further notice-and-comment rulemaking actions to act on those 
submissions. This would create a regime of unceasing rulemaking that 
would delay action on the redesignation request beyond the 18-month 
timeframe provided by the Act for this purpose.
    Second, a fundamental premise for redesignating a nonattainment 
area to attainment is that the area has attained the relevant NAAQS due 
to emission reductions from existing controls. Thus, an area for which 
a redesignation request has been submitted would have already attained 
the NAAQS as a result of satisfying statutory requirements that came 
due prior to the submission of the request. Absent a showing that 
unadopted and unimplemented requirements are necessary for future 
maintenance, it is reasonable to view the requirements applicable for 
purposes of evaluating the redesignation request as including only 
those SIP requirements that have already come due. These are the 
requirements that led to attainment of the NAAQS. To require, for 
redesignation approval, that a state also satisfy additional SIP 
requirements coming due after the state submits its complete 
redesignation request, and while EPA is reviewing it, would compel the 
state to do more than is necessary to attain the NAAQS, without a 
showing that the additional requirements are necessary for maintenance.

d. Subpart 4 Requirements and the Alabama Portion of the Chattanooga 
TN-GA Area Redesignation Request

    Even if EPA were to take the view that the Court's January 4, 2013, 
decision requires that, in the context of pending redesignations, 
subpart 4 requirements were due and in effect at the time the State 
submitted its redesignation request, EPA proposes to determine that the 
Alabama portion of the Chattanooga TN-GA Area still qualifies for 
redesignation to attainment. As explained below, EPA believes that the 
redesignation request for the Alabama portion of the Chattanooga TN-GA 
Area, though not expressed in terms of subpart 4 requirements, 
substantively meets the requirements of that subpart for purposes of 
redesignating the Alabama portion of the Chattanooga TN-GA Area to 
attainment.
    With respect to evaluating the relevant substantive requirements of 
subpart 4 for purposes of redesignating the Alabama portion of the 
Chattanooga TN-GA Area, EPA notes that subpart 4 incorporates 
components of subpart 1 of part D, which contains general air quality 
planning requirements for areas designated as nonattainment. See 
section 172(c). Subpart 4 itself contains specific planning and 
scheduling requirements for PM10\9\ nonattainment areas, and 
under the Court's January 4, 2013, decision in NRDC v. EPA, these same 
statutory requirements also apply for PM2.5 nonattainment 
areas. EPA has longstanding general guidance that interprets the 1990 
amendments to the CAA, making recommendations to states for meeting the 
statutory requirements for SIPs for nonattainment areas.\10\ In the 
General Preamble, EPA discussed the relationship of subpart 1 and 
subpart 4 SIP requirements and pointed out that subpart 1 requirements 
were to an extent ``subsumed by, or integrally related to, the more 
specific PM-10 requirements.'' See 57 FR 13538 (April 16, 1992). The 
subpart 1 requirements include, among other things, provisions for 
attainment demonstrations, RACM RFP, emissions inventories, and 
contingency measures.
---------------------------------------------------------------------------

    \9\ PM10 refers to particles nominally 10 micrometers 
in diameter or smaller.
    \10\ See, ``State Implementation Plans; General Preamble for the 
Implementation of Title I of the Clean Air Act Amendments of 1990,'' 
57 FR 13498 (April 16, 1992) (the ``General Preamble'').
---------------------------------------------------------------------------

    For the purposes of this redesignation, in order to identify any 
additional requirements which would apply under subpart 4, we are 
considering the Alabama portion of the Chattanooga TN-GA Area to be a 
``moderate'' PM2.5 nonattainment area. Under section 188 of 
the CAA, all areas designated nonattainment areas under subpart 4 would 
initially be classified by operation of law as ``moderate'' 
nonattainment areas and would remain moderate nonattainment areas 
unless and until EPA reclassifies the area as a ``serious'' 
nonattainment area. Accordingly, EPA believes that it is appropriate to 
limit the evaluation of the potential impact of subpart 4 requirements 
to those that would be applicable to moderate nonattainment areas. 
Sections 189(a) and (c) of subpart 4 apply to moderate nonattainment 
areas and include the following: (1) An approved permit program for 
construction of new and modified major stationary sources (section 
189(a)(1)(A)); (2) an attainment demonstration (section 189(a)(1)(B)); 
(3) provisions for RACM (section 189(a)(1)(C)); and (4) quantitative 
milestones demonstrating RFP toward attainment by the applicable 
attainment date (section 189(c)).
    The permit requirements of subpart 4, as contained in section 
189(a)(1)(A), refer to and apply the subpart 1 permit provisions 
requirements of sections 172

[[Page 67149]]

and 173 to PM10, without adding to them. Consequently, EPA 
believes that section 189(a)(1)(A) does not itself impose for 
redesignation purposes any additional requirements for moderate areas 
beyond those contained in subpart 1.\11\ In any event, in the context 
of redesignation, EPA has long relied on the interpretation that a 
fully approved nonattainment new source review program is not 
considered an applicable requirement for redesignation, provided the 
area can maintain the standard with a PSD program after redesignation. 
A detailed rationale for this view is described in 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.'' See also 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).
---------------------------------------------------------------------------

    \11\ The potential effect of section 189(e) on section 
189(a)(1)(A) for purposes of evaluating this redesignation is 
discussed below.
---------------------------------------------------------------------------

    With respect to the specific attainment planning requirements under 
subpart 4,\12\ when EPA evaluates a redesignation request under either 
subpart 1 or 4, any area that is attaining the PM2.5 
standard is viewed as having satisfied the attainment planning 
requirements for these subparts. As discussed above, for 
redesignations, EPA has for many years interpreted attainment-linked 
requirements as not applicable for areas attaining the standard.
---------------------------------------------------------------------------

    \12\ i.e., attainment demonstration, RFP milestone requirements, 
and RACM.
---------------------------------------------------------------------------

    Therefore, even if we were to consider the Court's January 4, 2013, 
decision in NRDC v. EPA to mean that attainment-related requirements 
specific to subpart 4 should be imposed retroactively \13\ and thus are 
now past due, those requirements do not apply to an area that is 
attaining the 1997 PM2.5 standard for the purpose of 
evaluating a pending request to redesignate the area to attainment. 
Elsewhere in this notice, EPA proposes to determine that the Area has 
attained the 1997 PM2.5 standard. Under its longstanding 
interpretation, EPA is proposing to determine here that the Area meets 
the attainment-related plan requirements of subparts 1 and 4.
---------------------------------------------------------------------------

    \13\ As explained above, EPA does not believe that the Court's 
January 4, 2013, decision should be interpreted so as to impose 
these requirements on the states retroactively. Sierra Club v. 
Whitman, supra.
---------------------------------------------------------------------------

    Thus, EPA is proposing to conclude that the requirements to submit 
an attainment demonstration under 189(a)(1)(B), a RACM determination 
under section 189(a)(1)(C), and a RFP demonstration under 189(c)(1) are 
satisfied for purposes of evaluating the redesignation request.

e. Subpart 4 and Control of PM2.5 Precursors

    The D.C. Circuit in NRDC v. EPA remanded to EPA the two rules at 
issue in the case with instructions to EPA to re-promulgate them 
consistent with the requirements of subpart 4. EPA in this section 
addresses the Court's opinion with respect to PM2.5 
precursors. While past implementation of subpart 4 for PM10 
has allowed for control of PM10 precursors such as 
NOX from major stationary, mobile, and area sources in order 
to attain the standard as expeditiously as practicable, CAA section 
189(e) specifically provides that control requirements for major 
stationary sources of direct PM10 shall also apply to 
PM10 precursors from those sources, except where EPA 
determines that major stationary sources of such precursors ``do not 
contribute significantly to PM10 levels which exceed the 
standard in the area.''
    EPA's 1997 PM2.5 implementation rule, remanded by the 
D.C. Circuit, contained rebuttable presumptions concerning certain 
PM2.5 precursors applicable to attainment plans and control 
measures related to those plans. Specifically, in 40 CFR 51.1002, EPA 
provided, among other things, that a state was ``not required to 
address VOC [and ammonia] as . . . PM2.5 attainment plan 
precursor[s] and to evaluate sources of VOC [and ammonia] emissions in 
the State for control measures.'' EPA intended these to be rebuttable 
presumptions. EPA established these presumptions at the time because of 
uncertainties regarding the emission inventories for these pollutants 
and the effectiveness of specific control measures in various regions 
of the country in reducing PM2.5 concentrations. EPA also 
left open the possibility for such regulation of VOC and ammonia in 
specific areas where that was necessary.
    The Court in its January 4, 2013, decision made reference to both 
section 189(e) and 40 CFR 51.1002, and stated that, ``In light of our 
disposition, we need not address the petitioners' challenge to the 
presumptions in [40 CFR 51.1002] that volatile organic compounds and 
ammonia are not PM2.5 precursors, as subpart 4 expressly 
governs precursor presumptions.'' NRDC v. EPA, at 27, n.10.
    Elsewhere in the Court's opinion, however, the Court observed:

    Ammonia is a precursor to fine particulate matter, making it a 
precursor to both PM2.5 and PM10. For a 
PM10 nonattainment area governed by subpart 4, a 
precursor is presumptively regulated. See 42 U.S.C. Sec.  7513a(e) 
[section 189(e)].

Id. at 21, n.7.

    For a number of reasons, EPA believes that its proposed 
redesignation of the Alabama portion of the Chattanooga TN-GA Area is 
consistent with the Court's decision on this aspect of subpart 4. 
First, while the Court, citing section 189(e), stated that ``for a 
PM10 area governed by subpart 4, a precursor is 
`presumptively regulated,''' the Court expressly declined to decide the 
specific challenge to EPA's 1997 PM2.5 implementation rule 
provisions regarding ammonia and VOC as precursors. The Court had no 
occasion to determine whether and how it was substantively necessary to 
regulate any specific precursor in a particular PM2.5 
nonattainment area, and did not address what might be necessary for 
purposes of acting upon a redesignation request.
    However, even if EPA takes the view that the requirements of 
subpart 4 were deemed applicable at the time that the state submitted 
the redesignation request, and disregards the implementation rule's 
rebuttable presumptions regarding ammonia and VOC as PM2.5 
precursors, the regulatory consequence would be to consider the need 
for regulation of all precursors from any sources in the area to 
demonstrate attainment and to apply the section 189(e) provisions to 
major stationary sources of precursors. In the case of the Chattanooga 
TN-GA Area, EPA believes that doing so is consistent with proposing 
redesignation of the area for the PM2.5 standard. The 
Chattanooga TN-GA Area has attained the standard without any specific 
additional controls of VOC and ammonia emissions from any sources in 
the Area.
    Precursors in subpart 4 are specifically regulated under the 
provisions of section 189(e), which requires, with important 
exceptions, control requirements for major stationary sources of 
PM10 precursors.\14\ Under subpart 1 and EPA's prior 
implementation rule, all major stationary sources of PM2.5 
precursors

[[Page 67150]]

were subject to regulation, with the exception of ammonia and VOC. 
Thus, we must address here whether additional controls of ammonia and 
VOC from major stationary sources are required under section 189(e) of 
subpart 4 in order to redesignate the area for the 1997 
PM2.5 standard. As explained below, we do not believe that 
any additional controls of ammonia and VOC are required in the context 
of this redesignation.
---------------------------------------------------------------------------

    \14\ Under either subpart 1 or subpart 4, for purposes of 
demonstrating attainment as expeditiously as practicable, a state is 
required to evaluate all economically and technologically feasible 
control measures for direct PM emissions and precursor emissions, 
and adopt those measures that are deemed reasonably available.
---------------------------------------------------------------------------

    In the General Preamble, EPA discusses its approach to implementing 
section 189(e). See 57 FR 13538 (April 16, 1992). With regard to 
precursor regulation under section 189(e), the General Preamble 
explicitly stated that control of VOCs under other Act requirements may 
suffice to relieve a state from the need to adopt precursor controls 
under section 189(e). See 57 FR 13542. EPA in this rulemaking proposes 
to determine that even if not explicitly addressed by the State in its 
submission, the State does not need to take further action with respect 
to ammonia and VOCs as precursors to satisfy the requirements of 
section 189(e). This proposed determination is based on our findings 
that: (1) The Alabama portion of the Chattanooga TN-GA Area contains no 
major stationary sources of ammonia, and (2) existing major stationary 
sources of VOC are adequately controlled under other provisions of the 
CAA regulating the ozone NAAQS.\15\ In the alternative, EPA proposes to 
determine that, under the express exception provisions of section 
189(e), and in the context of the redesignation of the Area, which is 
attaining the 1997 Annual PM2.5 standard, at present ammonia 
and VOC precursors from major stationary sources do not contribute 
significantly to levels exceeding the 1997 PM2.5 standard in 
the Chattanooga TN-GA Area. See 57 FR 13539.
---------------------------------------------------------------------------

    \15\ The Chattanooga TN-GA Area has reduced VOC emissions 
through the implementation of various control programs including 
various on-road and non-road motor vehicle control programs.
---------------------------------------------------------------------------

    EPA notes that its 1997 PM2.5 implementation rule 
provisions in 40 CFR 51.1002 were not directed at evaluation of 
PM2.5 precursors in the context of redesignation, but rather 
the rule assesses SIP plans and control measures required to bring a 
nonattainment area into attainment of the 1997 PM2.5 NAAQS. 
By contrast, redesignation to attainment primarily requires the area to 
have already attained due to permanent and enforceable emission 
reductions, and to demonstrate that controls in place can continue to 
maintain the standard. Thus, even if we regard the Court's January 4, 
2013, decision as calling for ``presumptive regulation'' of ammonia and 
VOC for PM2.5 under the attainment planning provisions of 
subpart 4, those provisions in and of themselves do not require 
additional controls of these precursors for an area that already 
qualifies for redesignation. Nor does EPA believe that requiring the 
State to address precursors differently than they have already would 
result in a substantively different outcome.
    Although, as EPA has emphasized, its consideration here of 
precursor requirements under subpart 4 is in the context of a 
redesignation to attainment, EPA's existing interpretation of subpart 4 
requirements with respect to precursors in attainment plans for 
PM10 contemplates that states may develop attainment plans 
that regulate only those precursors that are necessary for purposes of 
attainment in the area in question, i.e., states may determine that 
only certain precursors need be regulated for attainment and control 
purposes.\16\ Courts have upheld this approach to the requirements of 
subpart 4 for PM10.\17\ EPA believes that application of 
this approach to PM2.5 precursors under subpart 4 is 
reasonable. Because the Chattanooga TN-GA Area has already attained the 
1997 PM2.5 NAAQS with its current approach to regulation of 
PM2.5 precursors, EPA believes that it is reasonable to 
conclude in the context of this redesignation that there is no need to 
revisit the attainment control strategy with respect to the treatment 
of precursors. Even if the court's decision is construed to impose an 
obligation, in evaluating this redesignation request, to consider 
additional precursors under subpart 4, it would not affect EPA's 
approval here of Alabama's request for redesignation of the Alabama 
portion of the Chattanooga TN-GA Area. In the context of a 
redesignation, Alabama has shown that the Chattanooga TN-GA Area (of 
which Jackson County is a part) has attained the standard. Moreover, 
the State has shown, and EPA has proposed to determine, that attainment 
in this Area is due to permanent and enforceable emissions reductions 
on all precursors necessary to provide for continued attainment. It 
follows logically that no further control of additional precursors is 
necessary. Accordingly, EPA does not view the January 4, 2013, decision 
of the court as precluding redesignation of the Alabama portion of the 
Chattanooga TN-GA Area to attainment for the 1997 Annual 
PM2.5 NAAQS at this time. In sum, even if Alabama were 
required to address precursors for Chattanooga TN-GA Area under subpart 
4 rather than under subpart 1, EPA would still conclude that the 
Alabama portion of the Chattanooga TN-GA Area had met all applicable 
requirements for purposes of redesignation in accordance with section 
107(d)(3(E)(ii) and (v).
---------------------------------------------------------------------------

    \16\ See ``Approval and Promulgation of Implementation Plans for 
California--San Joaquin Valley PM-10 Nonattainment Area; Serious 
Area Plan for Nonattainment of the 24-Hour and Annual PM-10 
Standards,'' 69 FR 30006 (May 26, 2004) (approving a PM10 
attainment plan that impose controls on direct PM10 and 
NOX emissions and did not impose controls on 
SO2, VOC, or ammonia emissions).
    \17\ See Association of Irritated Residents v. EPA et al., 423 
F.3d 989 (9th Cir. 2005).
---------------------------------------------------------------------------

f. Maintenance Plan and Evaluation of Precursors

    With regard to the redesignation of the Alabama portion of the 
Chattanooga TN-GA Area, in evaluating the effect of the court's remand 
of EPA's implementation rule, which included presumptions against 
consideration of VOC and ammonia as PM2.5 precursors, EPA in 
this proposal is also considering the impact of the decision on the 
maintenance plan required under sections 175A and 107(d)(3)(E)(iv). To 
begin with, EPA notes that the Area has attained the 1997 Annual 
PM2.5 NAAQS and that the State has shown that attainment of 
that standard is due to permanent and enforceable emission reductions.
    EPA proposes to determine that the State's maintenance plan shows 
continued maintenance of the standard by tracking the levels of the 
precursors whose control brought about attainment of the 1997 
PM2.5 standard in the Chattanooga TN-GA Area. EPA therefore 
believes that the only additional consideration related to the 
maintenance plan requirements that results from the Court's January 4, 
2013, decision is that of assessing the potential role of VOC and 
ammonia in demonstrating continued maintenance in this area. As 
explained below, based upon documentation provided by Alabama and 
supporting information, EPA believes that the maintenance plan for the 
Alabama portion of the Chattanooga TN-GA Area need not include any 
additional emission reductions of VOC or ammonia in order to provide 
for continued maintenance of the standard.
    First, as noted above in EPA's discussion of section 189(e), VOC 
emission levels in this area have historically been well-controlled 
under SIP requirements related to ozone and other pollutants. Second, 
total ammonia emissions throughout the portion of Jackson County in the 
Chattanooga TN-

[[Page 67151]]

GA Area are estimated to be approximately 1,820.86 tons per year in 
2020, a slight increase over 2007 levels. See Table 7 below. As 
described below, available information shows that no precursor, 
including VOC and ammonia, is expected to increase significantly over 
the maintenance period so as to interfere with or undermine the State's 
maintenance demonstration.

 Table 7--Comparison of 2007 and 2020 VOC and Ammonia Emission Totals by
  Source Sector (tpy) for the Alabama Portion of the Chattanooga TN-GA
                                Area \18\
------------------------------------------------------------------------
                                          VOC               Ammonia
                                 ---------------------------------------
          Source sector                         Net                 Net
                                  2007  2020  change  2007  2020  change
------------------------------------------------------------------------
Nonpoint........................  712.  685.  -26.6   1,55  1,74  193.19
                                   30    66           2.38  5.57
Nonroad.........................  1,31  563.  -754.6  0.94  1.01  0.07
                                  8.58   98
Onroad..........................  1,00  327.  -677.8  40.4  21.5  -18.89
                                  5.61   77      4      3     4
Point...........................  142.  161.  19.03   74.2  52.7  -21.5
                                   71    74             4     4
                                 ---------------------------------------
    Total.......................  3,17  1,73  -1,440  1,66  1,82  152.86
                                  9.20  9.15   .05    8.00  0.86
------------------------------------------------------------------------

    Alabama's maintenance plan shows that emissions of SO2, 
NOX, and PM2.5 are projected to decrease over the 
maintenance period in the Alabama Portion of the Chattanooga, TN-GA 
Area by 22,287.4 tpy, 15,020.16, and 220.45 tpy, respectively. See 
Table 6, above. In addition, emissions inventories used in the 
regulatory impact analysis (RIA) for the 2012 PM2.5 NAAQS 
\19\ show that VOC emissions are projected to decrease by 1,440.05 tpy, 
and the ammonia emissions are projected to increase by 152.86 tpy 
between 2007 and 2020. Although ammonia emissions are projected to 
increase slightly between 2007 and 2020, the decrease in emissions of 
other precursors in comparison will keep the Area well below the 
standard. See Table 6 and 7, above. While the RIA emissions inventories 
are only projected out to 2020, there is no reason to believe that this 
overall downward trend would not continue through 2025. Given that the 
Chattanooga TN-GA Area is already attaining the 1997 Annual 
PM2.5 NAAQS even with the current level of emissions from 
sources in the Area, the overall trend of emissions inventories would 
be consistent with continued attainment. Indeed, projected emissions 
reductions for the precursors that the State is addressing for purposes 
of the 1997 Annual PM2.5 NAAQS indicate that the Area should 
continue to attain the NAAQS following the precursor control strategy 
that the State has already elected to pursue. Even if VOC and ammonia 
emissions were to increase unexpectedly between 2020 and 2025, the 
overall emission reductions projected in SO2, 
NOX, and PM2.5 would be sufficient to offset any 
increases. For these reasons, EPA believes that local emissions of all 
the potential PM2.5 precursors will not increase to the 
extent that they will cause monitored PM2.5 levels to 
violate the 1997 Annual PM2.5 standard during the 
maintenance period.
---------------------------------------------------------------------------

    \18\ These emissions estimates were taken from the emissions 
inventories developed for the regulatory impact analysis for the 
2012 PM2.5 NAAQS.
    \19\ The RIA for the 2012 PM2.5 NAAQS standard can be 
found on EPA's Web site at http://www.epa.gov/ttn/ecas/regdata/RIAs/finalria.pdf.
---------------------------------------------------------------------------

    In addition, available air quality data and modeling analyses show 
continued maintenance of the standard during the maintenance period. As 
noted in section V, above, the Chattanooga TN-GA Area recorded a 
PM2.5 design value of 10.5 [mu]g/m\3\ during 2011-2013, the 
most recent three years available with complete, quality-assured and 
certified ambient air monitoring data. This is well below the 1997 
Annual PM2.5 NAAQS of 15.0 [micro]g/m\3\. Moreover, the 
modeling analysis conducted for the RIA for the 2012 PM2.5 
NAAQS indicates that the design value for this area is expected to 
continue to decline through 2020. Given the decrease in overall 
precursor emissions projected through 2025, it is reasonable to 
conclude that monitored PM2.5 levels in this area will also 
continue to decrease through 2025.
    Thus, EPA believes that there is ample justification to conclude 
that the Alabama portion of the Chattanooga TN-GA Area should be 
redesignated, even taking into consideration the emissions of VOC and 
ammonia potentially relevant to PM2.5. After consideration 
of the D.C. Circuit's January 4, 2013, decision, and for the reasons 
set forth in this notice, EPA continues to propose approval of the 
State's maintenance plan and its request to redesignate the Alabama 
portion of the Chattanooga TN-GA Area to attainment for the 1997 Annual 
PM2.5 NAAQS.

VII. What is EPA's analysis of Alabama's proposed regional on-road 
motor vehicle insignificance determination for the Alabama portion of 
the Chattanooga TN-GA area?

    Under section 176(c) of the CAA, new transportation plans, 
programs, and projects, such as the construction of new highways, must 
``conform'' to (i.e., be consistent with) the part of 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 or any interim milestones. If a transportation 
plan does not conform, most new projects that would expand the capacity 
of roadways cannot go forward. Regulations at 40 CFR part 93 set forth 
EPA policy, criteria, and procedures for demonstrating and assuring 
conformity of such transportation activities to a SIP. The regional 
emissions analysis is one, but not the only, requirement for 
implementing transportation conformity. Transportation conformity is a 
requirement for nonattainment and maintenance areas. Maintenance areas 
are areas that were previously nonattainment for a particular NAAQS but 
have since been redesignated to attainment with an approved maintenance 
plan for that NAAQS.
    Under the CAA, states are required to submit, at various times, 
control strategy SIPs and maintenance plans in nonattainment areas. 
These control strategy SIPs (including RFP and attainment 
demonstration) and maintenance plans create MVEBs for criteria 
pollutants and/or their precursors to address pollution from cars and 
trucks. Per 40 CFR part 93, a MVEB must be established for the last 
year of the maintenance plan. A state

[[Page 67152]]

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.
    Today's action addresses the element regarding on-road motor 
vehicle emissions and the requirement to establish MVEB. EPA is 
proposing to find that the direct PM2.5 and NOX 
emission contribution from motor vehicles in the Alabama portion of the 
Area are insignificant to the air pollution in the Chattanooga TN-GA 
Area. The result of this determination, if finalized, is that Alabama 
will not need to develop MVEB for direct PM2.5 and 
NOX for the Alabama portion of the Chattanooga TN-GA Area 
and the Metropolitan Planning Organization or Department of 
Transportation (whichever is applicable) will not need to perform a 
regional emissions analysis for either pollutant when it demonstrates 
conformity. See below for further information on the insignificance 
determination.
    Regional on-road motor vehicle insignificance. For motor vehicle 
emissions budgets to be approvable, they must meet, at a minimum, EPA's 
adequacy criteria (40 CFR 93.118(e)(4)). In certain instances, the 
Transportation Conformity Rule allows areas to forgo establishment of a 
MVEB where it is demonstrated that the regional motor vehicle emissions 
for a particular pollutant or precursor are an insignificant 
contributor to the air quality problem in an area. The general criteria 
for insignificance determinations can be found in 40 CFR 93.109(f). 
Insignificance determinations are based on a number of factors, 
including (1) the percentage of motor vehicle emissions in context of 
the total SIP inventory; (2) the current state of air quality as 
determined by monitoring data for that NAAQS; (3) the absence of SIP 
motor vehicle control measures; and (4) historical trends and future 
projections of the growth of motor vehicle emissions. EPA's rationale 
for providing for insignificance determinations is described in the 
July 1, 2004, revision to the Transportation Conformity Rule at 69 FR 
40004.\20\ Specifically, the rationale is explained on page 40061 under 
the subsection entitled ``XXIII.B. Areas With Insignificant Motor 
Vehicle Emissions.'' Any insignificance determination under review by 
EPA is subject to the adequacy and approval process for EPA's action on 
the SIP.
---------------------------------------------------------------------------

    \20\ In the March 24, 2010, final rule (75 FR 14260), provisions 
for insignificance determinations were outlined in 40 CFR 93.109(m). 
EPA revised 40 CFR 93.109 in its March 14, 2012, final rule (77 FR 
14979), and the provisions for insignificance determinations are now 
located at 40 CFR 93.109(f).
---------------------------------------------------------------------------

    Through the adequacy and SIP approval process, EPA may find that a 
SIP demonstrates that regional motor vehicle emissions are an 
insignificant contributor to the air quality problem for the pollutant 
or precursor at issue. Upon the effective date of EPA's adequacy 
determination, federal regulations no longer require a regional 
emissions analysis (for the purpose of transportation conformity 
implementation) for the relevant insignificant pollutant or precursor. 
Areas with insignificant regional motor vehicle emissions for a 
pollutant or precursor are still required to make a conformity 
determination that satisfies other relevant conformity requirements. 
Additionally, such areas are required to satisfy the regional emissions 
analysis requirements for pollutants or precursors for which EPA has 
not made a determination of insignificance.
    The maintenance plan for the Alabama portion of the Chattanooga TN-
GA Area, included as part of the SIP revision, contains a regional on-
road motor vehicle insignificance determination for the direct 
PM2.5 and NOX contribution of motor vehicles in 
the Alabama portion of the Chattanooga TN-GA Area to the air quality 
problem in the Chattanooga TN-GA Area. As part of the preparation for 
its redesignation request, Alabama used the on-road emissions of 
PM2.5 and NOX from motor vehicles in that portion 
of Jackson County, from the document titled ``Chattanooga Non-
Attainment Area Year 2030 Conformity Determination Report.'' In order 
to estimate on-road mobile source emissions for the nonattainment 
portion of Jackson County, a ratio of the size of the nonattainment 
portion of Jackson County in square miles to the size of the entire 
county in square miles was calculated. The nonattainment portion of 
Jackson County was determined to be only about one percent of the total 
area of Jackson County. The same rational was applied to obtain area 
and non-road mobile source emissions for the nonattainment portion for 
the county. Alabama determined that direct PM2.5 and 
NOX emissions from on-road mobile sources in the Alabama 
portion of the Chattanooga TN-GA Area are 0.2 percent, and 0.18 
percent, respectively, of the total emissions from on-road mobile 
source in the entire Chattanooga TN-GA Area for 2007, 2017, and 2025.
    The information provided by Alabama supports EPA's proposal to 
determine that the direct PM2.5 and NOX 
contribution from on-road vehicles in the Alabama portion of the 
Chattanooga TN-GA Area are insignificant to the PM2.5 air 
pollution the Chattanooga TN-GA Area. As shown in Tables 2 through 6 
above, Alabama's maintenance plan demonstrates that on-road direct 
PM2.5 emissions and NOX emissions will continue 
to decrease through 2025, the end of the initial maintenance plan for 
the Alabama portion of the Chattanooga TN-GA Area. In addition, since 
2007, the PM2.5 design value concentration has decreased by 
approximately 15 percent such that the Area is now attaining the Annual 
PM2.5 NAAQS with a 2011-2013 design value of 10.5 [micro]g/
m\3\, well below the standard of 15.0 [micro]g/m\3\. According to 
information provided by Alabama, point sources contributed over 99 
percent of the emissions in future years in the Alabama portion of the 
Chattanooga TN-GA Area. The maintenance plan does not contain any 
control measures that apply to on-road motor vehicles.
    After evaluating the information provided by Alabama and weighing 
the factors for the insignificance determination outlined in 40 CFR 
93.109(f), EPA is now proposing to approve Alabama's determination that 
the direct PM2.5 and NOX contribution from motor 
vehicle emissions in the Alabama portion of the Chattanooga Area are 
insignificant to the pollution problem in the Chattanooga TN-GA Area. 
EPA's insignificance determination should be considered and 
specifically noted in the transportation conformity documentation that 
is prepared for the Area. EPA is proposing that the submitted 
insignificance finding is consistent with maintenance of the 1997 
Annual PM2.5 NAAQS through 2025.

VIII. What is the status of EPA's adequacy determination for the on-
road motor vehicle insignificance determination for the Alabama portion 
of the Chattanooga TN-GA area?

    When reviewing submitted ``control strategy'' SIPs or maintenance 
plans containing MVEB and/or insignificance determinations, EPA may 
affirmatively find the MVEB and/or insignificance determination 
contained therein

[[Page 67153]]

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. Further, 
once EPA affirmatively finds the submitted insignificance determination 
is adequate for transportation conformity purposes, the transportation 
partners are relieved of performing a regional emissions analysis of 
that pollutant or precursor but must document the insignificance 
determination in its conformity determination.
    EPA's substantive criteria for determining adequacy of an MVEB and/
or insignificance determination 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 determination. This process for determining the adequacy of 
submitted MVEB for transportation conformity purposes was initially 
outlined in EPA's May 14, 1999, guidance, ``Conformity Guidance on 
Implementation of March 2, 1999, Conformity Court Decision.'' EPA 
adopted regulations to codify the adequacy process 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 transportation conformity purposes 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, Alabama's maintenance plan submission 
includes an insignificance determination that direct PM2.5 
and NOX emissions from on-road motor vehicles are an 
insignificant contributor to the air quality problem in the Chattanooga 
TN-GA Area. The Alabama maintenance SIP submission, including the on-
road motor vehicle insignificance finding, was open for public comment 
on EPA's adequacy Web site found at: http://www.epa.gov/otaq/stateresources/transconf/currsips.htm. The EPA public comment period 
closed on October 22, 2014. EPA did not receive any comments on the 
adequacy of the insignificance determination, nor did EPA receive any 
requests for the SIP revision.
    EPA intends to make its determination on the adequacy of the 
insignificance finding for the Alabama portion of the Chattanooga TN-GA 
Area for transportation conformity purposes in the near future. Section 
93.109(f) states that a regional emissions analysis is no longer 
necessary if EPA finds through the adequacy or approval process that a 
SIP demonstrates that regional motor vehicle emissions are an 
insignificant contributor to the air quality problem for that 
pollutant/precursor. A finding of insignificance does not change the 
requirement for a regional analysis for other pollutants and precursors 
and does not change the requirement for hot-spot analysis. After EPA 
finds the insignificance determination adequate or approves it, this 
on-road motor vehicle insignificance finding for direct 
PM2.5 and NOX applies to future transportation 
conformity determinations.\21\
---------------------------------------------------------------------------

    \21\ The Alabama portion of the Chattanooga TN-GA Area already 
has an adequate insignificance finding for its previously-submitted 
attainment demonstration.
---------------------------------------------------------------------------

IX. Proposed Actions on the Redesignation Request and Maintenance Plan 
SIP Revision for the Alabama Portion of the Chattanooga TN-GA Area

    On May 31, 2011, EPA determined that the Chattanooga TN-GA Area was 
attaining the 1997 Annual PM2.5 NAAQS. See 76 FR 31239. EPA 
is now taking two separate but related actions regarding the Area's 
redesignation and maintenance of the 1997 Annual PM2.5 
NAAQS.
    First, EPA is proposing to determine that, based upon review of 
complete, quality-assured and certified ambient monitoring data for the 
2007-2009 period, and review of data in AQS for 2010 through 2013 that 
the Chattanooga TN-GA Area continues to attain the 1997 Annual 
PM2.5 NAAQS. EPA is also proposing to determine that the 
Alabama portion of the Chattanooga TN-GA Area has met the criteria 
under CAA section 107(d)(3)(E) for redesignation from nonattainment to 
attainment for the 1997 Annual PM2.5 NAAQS. On this basis, 
EPA is proposing to approve Alabama's redesignation request for the 
Alabama portion of the Chattanooga TN-GA Area.
    Second, EPA is proposing to approve the maintenance plan for the 
Alabama portion of the Chattanooga TN-GA Area as meeting the 
requirements of section 175A of the CAA. The maintenance plan 
demonstrates that the Area will continue to maintain the 1997 Annual 
PM2.5 NAAQS.
    If finalized, approval of the redesignation request would change 
the official designation of the portion of Jackson County in the 
Chattanooga TN-GA Area for the 1997 Annual PM2.5 NAAQS, 
found at 40 CFR part 81 from nonattainment to attainment. EPA is also 
proposing to approve, into the Alabama SIP, the maintenance plan for 
the Alabama portion of the Chattanooga TN-GA Area.

X. 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 Alabama's redesignation request would change the legal designation 
of a portion of Jackson County in Alabama for the 1997 Annual 
PM2.5 NAAQS, found at 40 CFR part 81, from nonattainment to 
attainment. Approval of the ADEM's request would also incorporate a 
plan for maintaining the 1997 Annual PM2.5 NAAQS in the 
Alabama portion of the Chattanooga TN-GA Area through 2025 into the 
Alabama SIP. This maintenance plan includes contingency measures to 
remedy any future violations of the 1997 Annual PM2.5 NAAQS 
and procedures for evaluation of potential violations. Additionally, 
EPA is notifying the public of the status of its adequacy determination 
for the NOX and PM2.5 insignificance pursuant to 
40 CFR 93.118(f)(1).

XI. Statutory and Executive Order Reviews

    Under the CAA, redesignation of an area to attainment and the 
accompanying approval of a maintenance plan under section 107(d)(3)(E) 
are actions that affect the status of a geographical area and do not 
impose any additional regulatory requirements on sources beyond those 
imposed by state law. A redesignation to attainment does not in and of 
itself create any new requirements, but rather results in the 
applicability of requirements contained in the CAA for areas that have 
been redesignated to attainment. Moreover, the Administrator is 
required to approve a SIP submission that complies with the provisions 
of the Act and applicable Federal regulations. 42 U.S.C. 7410(k); 40 
CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to 
approve state choices, provided that they meet the criteria of the CAA. 
Accordingly, these proposed actions merely approve state law as

[[Page 67154]]

meeting federal requirements and does not impose additional 
requirements beyond those imposed by state law. For that reason, these 
proposed actions:
     Are not ``significant regulatory action[s]'' subject to 
review by the Office of Management and Budget under Executive Order 
12866 (58 FR 51735, October 4, 1993);
     do not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     are certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     do not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     do not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     are not economically significant regulatory actions based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     are not significant regulatory actions subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     are not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the CAA; and
     do not provide EPA with the discretionary authority to 
address, as appropriate, disproportionate human health or environmental 
effects, using practicable and legally permissible methods, under 
Executive Order 12898 (59 FR 7629, February 16, 1994).
    The SIP is not approved to apply on any Indian reservation land or 
in any other area where EPA or an Indian tribe has demonstrated that a 
tribe has jurisdiction. In those areas of Indian country, the rule does 
not have tribal implications as specified by Executive Order 13175 (65 
FR 67249, November 9, 2000), nor will it impose substantial direct 
costs on tribal governments or preempt tribal law.

List of Subjects

40 CFR Part 52

    Environmental protection, Air pollution control, Intergovernmental 
relations, Reporting and recordkeeping requirements, and Particulate 
matter.

40 CFR Part 81

    Environmental protection, Air pollution control.

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

    Dated: November 3, 2014.
V. Anne Heard,
Acting Regional Administrator, Region 4.
[FR Doc. 2014-26736 Filed 11-10-14; 8:45 am]
BILLING CODE 6560-50-P