[Federal Register Volume 79, Number 218 (Wednesday, November 12, 2014)]
[Proposed Rules]
[Pages 67120-67137]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-26735]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R04-OAR-2014-0267; FRL-9919-18-Region 4]


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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: On September 14, 2012, the Georgia Department of Natural 
Resources, through the Georgia Environmental Protection Division (GA 
EPD), submitted a request to redesignate the Georgia 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 Georgia portion of the Chattanooga TN-GA Area. The Georgia portion 
of the Chattanooga TN-GA Area is comprised of two counties: Catoosa and 
Walker Counties in Georgia. The Environmental Protection Agency (EPA) 
is proposing to approve the redesignation request and the related SIP 
revision, including GA EPD's plan for maintaining attainment of the 
PM2.5 standard, for the Georgia portion of the Chattanooga 
TN-GA Area. EPA is also proposing to approve into the Georgia SIP the 
motor vehicle emission budgets (MVEBs) for nitrogen oxides 
(NOX) and PM2.5 for the year 2025 for the Georgia 
portion of the Chattanooga TN-GA Area. On April 23, 2013, Alabama 
submitted a request to redesignate the Alabama 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-2014-0267, by one of the following methods:
    1. www.regulations.gov: Follow the on-line instructions for 
submitting comments.
    2. Email: [email protected].
    3. Fax: (404) 562-9019.
    4. Mail: EPA-R04-OAR-2014-0267, Regulatory Development Section, Air 
Planning Branch, Air, Pesticides and Toxics Management Division, U.S. 
Environmental Protection Agency, Region 4, 61 Forsyth Street SW., 
Atlanta, Georgia 30303-8960.
    5. Hand Delivery or Courier: Ms. Lynorae Benjamin, Chief, 
Regulatory Development Section, Air Planning Branch, Air, Pesticides 
and Toxics Management Division, U.S. Environmental Protection Agency, 
Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960. Such 
deliveries are only accepted during the Regional Office's normal hours 
of operation. The Regional Office's official hours of business are 
Monday through Friday, 8:30 a.m. to 4:30 p.m., excluding Federal 
holidays.
    Instructions: Direct your comments to Docket ID No. EPA-R04-OAR-
2014-0267. EPA 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 a.m. to 4:30 p.m., 
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 [email protected].

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 the January 4, 2013, D.C. Circuit decision 
regarding PM2.5 implementation under Subpart 4?
VII. What is EPA's analysis of Georgia's proposed NOX and 
PM2.5 MVEBs for the Georgia portion of the Chattanooga 
TN-GA Area?
VIII. What is the status of EPA's adequacy determination for the 
proposed NOX and PM2.5 MVEBs for 2025 for the 
Georgia portion of the Chattanooga TN-GA Area?
IX. Proposed Actions on the Redesignation Request and Maintenance 
Plan SIP Revisions Including Approval of the

[[Page 67121]]

NOX and PM2.5 MVEBs for 2025 for the Georgia 
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 the 
Chattanooga TN-GA Area is continuing to attain the 1997 Annual 
PM2.5 NAAQS \1\ and to take additional actions related to 
Georgia's request to redesignate the Georgia portion of the Chattanooga 
TN-GA Area, which is summarized as follows and described in greater 
detail throughout this notice of proposed rulemaking. EPA proposes: (1) 
to redesignate the Georgia 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), 
Georgia's 1997 Annual PM2.5 NAAQS maintenance plan, 
including the associated MVEBs, for the Georgia portion of the 
Chattanooga TN-GA Area into the Georgia 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 Georgia 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 Catoosa and Walker 
Counties in Georgia, located within the Chattanooga TN-GA Area, from 
nonattainment to attainment for the 1997 Annual PM2.5 NAAQS.
    Second, EPA is proposing to approve Georgia's 1997 Annual 
PM2.5 NAAQS maintenance plan for the Georgia 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 for the 1997 
Annual PM2.5 NAAQS through 2025. The maintenance plan that 
EPA is proposing to approve today includes on-road MVEBs for direct 
PM2.5 and NOX for the Georgia portion of the 
Chattanooga TN-GA Area for transportation conformity purposes. EPA is 
proposing to approve the 2025 MVEBs into the Georgia SIP that are 
included as part of Georgia'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 Georgia 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 an update of the status of EPA's 
adequacy process for the 2025 MVEBs for PM2.5 and 
NOX for the Georgia portion of the Chattanooga TN-GA Area. 
Please see Section VIII of this proposed rulemaking for further 
explanation of this process and for more details.
    Today's notice of proposed rulemaking is in response to Georgia's 
September 14, 2012, SIP revision, which requests redesignation of the 
Georgia 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 that NAAQS to EPA 
for further consideration. See American Farm Bureau Federation and 
National Pork Producers Council, et al. v. EPA, 559 F.3d 512 (D.C. 
Cir. 2009). However, given that the 1997 and 2006 Annual NAAQS are 
essentially identical, attainment of the 1997 Annual NAAQS would 
also indicate attainment of the remanded 2006 Annual NAAQS.
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    On January 5, 2005, and supplemented on April 14, 2005, EPA 
designated Catoosa and Walker Counties in Georgia, in association with 
counties in Alabama 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 Georgia portion of the Chattanooga TN-GA Area 
was classified unclassifiable/attainment for the 1997 24-hour 
PM2.5 NAAQS. EPA did not promulgate designations for the 
2006 Annual PM2.5 NAAQS because that NAAQS was essentially 
identical to the 1997 Annual PM2.5 NAAQS. Therefore, the 
Georgia 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. This 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

[[Page 67122]]

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 PM2.5 NAAQS for the Chattanooga TN-GA 
Area. As a result, on September 14, 2012, Georgia requested 
redesignation of the Georgia 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 the 1997 PM2.5 NAAQS had been 
achieved for the 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 standard. 
While annual PM2.5 concentrations are dependent on a variety 
of conditions, the overall improvement in annual PM2.5 
concentrations in the Georgia portion of the Chattanooga TN-GA Area can 
be attributed to the reduction of pollutant emissions, as 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 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 September 14, 2012, GA EPD requested the redesignation of the 
Georgia 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 Georgia portion of this 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 both the NOX and direct PM2.5 MVEBs for the 
Georgia portion of the Chattanooga TN-GA Area. Additionally, EPA is 
also approving the MVEBs for both NOX and direct 
PM2.5 that were included in Georgia'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 Georgia portion of the 
Chattanooga TN-GA Area to attainment for the 1997 Annual 
PM2.5 NAAQS; and (2) approve into the Georgia SIP the 1997 
Annual PM2.5 NAAQS maintenance plan, including the 
associated MVEBs, for the for the Georgia 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 Georgia 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 
[micro]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

[[Page 67123]]

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, Georgia.......    132950002       * 12.3         10.6         10.1         10.0         10.5
Siskin Drive/UTC, Tennessee................  Hamilton County, Tennessee...    470654002         12.9         11.6         11.1         10.9         10.0
Maxwell Road/East Ridge, Tennessee.........  Hamilton County, Tennessee...    470650031         12.7         11.7         11.2         11.1         10.1
Soddy-Daisy High School, Tennessee.........  Hamilton County, Tennessee...    470651011         11.8         11.4         11.0         11.2          9.8
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* Values subject to data substitution (76 FR 15895).

    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 
Georgia 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, GA EPD has committed to continue 
monitoring in this Area in accordance with 40 CFR part 58.

Criteria (5)--Georgia Has Met All Applicable Requirements Under Section 
110 and Part D of the CAA; and Criteria (2)--Georgia Has a Fully 
Approved SIP Under Section 110(k) for the Georgia 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 Georgia has met all applicable SIP requirements 
for the Georgia 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 Georgia 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 Georgia 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

[[Page 67124]]

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 25, 2012, EPA approved all infrastructure SIP elements 
required under section 110(a)(2) for the 1997 Annual PM2.5 
NAAQS with the exception of the visibility element under section 
110(a)(2)(D)(i)(II) (also known as ``prong 4''). See 77 FR 65125. EPA 
approved prong 4 for the 1997 Annual PM2.5 NAAQS on May 7, 
2014. See 79 FR 26143. 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 Georgia 
portion of the Chattanooga TN-GA Area.
    Title I, Part D, subpart 1 applicable SIP requirements. EPA 
proposes to determine that the Georgia SIP meets the applicable SIP 
requirements for the Georgia 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 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 March 1, 2012, 
EPA approved Georgia's 2002 base-year emissions inventory for the 
Georgia portion of the Chattanooga TN-GA Area as part of the SIP 
revision submitted by GA EPD to provide for attainment of the 1997 
PM2.5 NAAQS in the Area. See 77 FR 12487.
    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)

[[Page 67125]]

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.'' 
Georgia has demonstrated that the Georgia portion of the Chattanooga 
TN-GA Area will be able to maintain the NAAQS without part D NSR in 
effect, and therefore, Georgia need not have fully approved part D NSR 
programs prior to approval of the redesignation request. Georgia's PSD 
program will become effective in the Georgia 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 
Georgia 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. 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 Georgia 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 Georgia 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 Georgia SIP for the Georgia 
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, Georgia 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 Georgia portion of the Chattanooga TN-GA Area (e.g., 77 FR 65125 
(October 25, 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 Georgia 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

[[Page 67126]]

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 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 Georgia's SIP on October 9, 2007, 
that addressed the requirements of CAIR for the purpose of reducing 
SO2 and NOX emissions (see 72 FR 57202), and 
Georgia'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-
40 and B-59.\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.
---------------------------------------------------------------------------

    State-only Measures. In its redesignation request, GA EPD

[[Page 67127]]

identified Georgia rules 391-3-1-.02(2)(sss) (``Multipollutant Rule'') 
and 391-3-1-.02(2)(uuu) (``SO2 Emissions from Electric Steam 
Utility Steam Generating Units'') as two state-only measures that 
improve PM2.5 air quality in the Chattanooga TN-GA Area. 
Rule (sss) requires flue gas desulfurization (FGD) and selective 
catalytic reduction (SCR) on the majority of the coal-fired EGUs in 
Georgia, and Rule (uuu) requires a 95 percent reduction in 
SO2 emissions from the majority of the coal-fired EGUs in 
Georgia. The implementation dates for Rules (sss) and (uuu) vary by 
EGU, starting on December 31, 2008, for Rule (sss) and January 1, 2010 
for Rule (uuu). By the end of 2009, FGDs mandated by Rule (sss) were 
operating at Plant Hammond (4 of 4 subject units), Plant Bowen (2 of 4 
subject units), and Plant Wansley (1 of 2 subject units). Although GA 
EPD discusses the emissions reductions resulting from Rules (sss) and 
(uuu) in its redesignation request, these rules were not necessary for 
attainment of the 1997 Annual PM2.5 NAAQS for the reasons 
discussed below. EPA has therefore not relied on these state-only rules 
as a basis for proposing approval of the redesignation request and 
associated maintenance plan.
    GA EPD analyzed the sensitivity of PM2.5 concentrations 
at the four PM2.5 monitors in the Chattanooga TN-GA Area to 
reductions in SO2 emissions due to the installation and 
operation of FGD by the end of 2009 pursuant to Rule (sss) at the EGUs 
identified above.\7\ The analysis was based on modeling conducted by 
the Visibility Improvement State and Tribal Association of the 
Southeast (VISTAS) using emissions inventories for 2002 and 2009 and 
CMAQ version 4.5 with the CB-IV chemical mechanism.
---------------------------------------------------------------------------

    \7\ GA EPD, Sensitivity of Annual PM2.5 in 
Chattanooga to SO2 Emission Reductions Resulting from 
Georgia's Multipollutant Rule [391-3-1-.02(2)(sss)] (attached to an 
October 28, 2014 email from James Boylan, GA EPD, to Lynorae 
Benjamin, EPA Region 4). The email and attachments are included in 
the docket for this action.
---------------------------------------------------------------------------

    Based on the sensitivity analysis, GA EPD concluded that the 
emissions reductions from Rule (sss) were not necessary for attainment 
of the 1997 Annual PM2.5 NAAQS.\8\ GA EPD estimated that the 
Rule (sss) controls in place by the end of 2009 impacted the 2007-09 
Annual PM2.5 design value by approximately 0.5 [mu]g/m\3\. 
Therefore, removing the effect of these controls would result in a 
2007-09 design value of 13.4 [mu]g/m\3\ (12.9 [mu]g/m\3\ plus 0.5 
[mu]g/m\3\), well below the 15.0 [mu]g/m\3\ standard.\9\ Furthermore, 
Rule (uuu) was not necessary for attainment of the 1997 Annual 
PM2.5 NAAQS in 2007-09 because it was not implemented until 
January 1, 2010. All monitors in the Chattanooga Area have registered 
annual PM2.5 readings below 15 [mu]g/m\3\ since 2006, and 
the 2006-08 design value for the Area was below the 1997 Annual 
PM2.5 NAAQS.
---------------------------------------------------------------------------

    \8\ Because Rules (sss) and (uuu) were unnecessary for 
attainment in 2007-09 and because the permanent and enforceable 
measures necessary for attainment are expected to remain in place 
during the first maintenance period, these rules are also 
unnecessary for maintenance of the standard through 2025.
    \9\ In its redesignation request and October 28, 2014 technical 
analysis, Georgia identified a 2007-09 design value of 12.7 [mu]g/
m\3\. The correct design value is 12.9 [mu]g/m\3\ as identified in 
Table 1 of this Federal Register notice.
---------------------------------------------------------------------------

Criteria (4)--The Georgia 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 
Georgia portion of the Chattanooga TN-GA Area to attainment for the 
1997 Annual PM2.5 NAAQS, GA EPD 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, GA EPD 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 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 GA EPD's 
maintenance plan includes all the necessary components and is thus 
proposing to approve it as a revision to the Georgia 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. GA EPD 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. GA EPD began development of the attainment 
inventory by first generating a baseline emissions inventory for the 
Georgia portion of the Chattanooga TN-GA Area. 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. In addition, emissions have been calculated by interpolation 
for the years 2014 and 2020. 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 emissions, was prepared for 
Georgia 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). The Georgia Department of Transportation 
developed the 2007 inventory of on-road mobile emissions. The 2007 
SO2, NOX, and PM2.5 emissions for the 
Georgia 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.

[[Page 67128]]

2. Maintenance Demonstration
    The September 14, 2012, final submittal includes a maintenance plan 
for the Georgia 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 and that a slight 
increase in direct PM2.5 emissions will not interfere with 
maintenance.
    (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. Per 40 CFR part 93, 
NOX and PM2.5 MVEBs were established for the last 
year (2025) of the maintenance plan.
    (iv) Provides, as shown in Tables 2, 3, 4, 5, and 6 below, the 
actual and projected emissions inventories, in tpy, for the Georgia 
portion of the Chattanooga TN-GA Area.

  Table 2--Actual (2007) and Projected Point Source Emissions for the Georgia Portion of the Chattanooga TN-GA
                                                      Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2007            2014            2017            2020            2025
----------------------------------------------------------------------------------------------------------------
SO2.............................             280             285             287             290             295
NOX.............................              48              49              49              50              52
PM2.5...........................               0               0               0               0               0
----------------------------------------------------------------------------------------------------------------


Table 3--Actual (2007) and Projected Non-Point Source Emissions for the Georgia Portion of the Chattanooga TN-GA
                                                      Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2007            2014            2017            2020            2025
----------------------------------------------------------------------------------------------------------------
SO2.............................              77              81              82              84              87
NOX.............................             359             397             414             430             456
PM2.5...........................           1,548           1,729           1,807           1,878           1,998
----------------------------------------------------------------------------------------------------------------


Table 4--Actual (2007) and Projected On-Road Mobile Sources Emissions for the Georgia Portion of the Chattanooga
                                                   TN-GA Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2007            2014            2017            2020            2025
----------------------------------------------------------------------------------------------------------------
SO2.............................              20              17              15              14              11
NOX.............................           4,442           3,112           2,542           1,972           1,022
PM2.5...........................             134              96              80              63              36
----------------------------------------------------------------------------------------------------------------


Table 5--Actual (2007) and Projected Non-Road Mobile Source Emissions for the Georgia Portion of the Chattanooga
                                                   TN-GA Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2007            2014            2017            2020            2025
----------------------------------------------------------------------------------------------------------------
SO2.............................              27             8.8             0.8             0.8             0.9
NOX.............................             633             450             372             336             277
PM2.5...........................              51              38              32              28              22
----------------------------------------------------------------------------------------------------------------


 Table 6--Actual (2007) and Projected Emissions for All Sectors for the Georgia Portion of the Chattanooga TN-GA
                                                      Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2007            2014            2017            2020            2025
----------------------------------------------------------------------------------------------------------------
SO2.............................             404             391             385             389             394
NOX.............................           5,482           4,009           3,377           2,788           1,806
PM2.5...........................           1,733           1,863           1,918           1,970           2,056
----------------------------------------------------------------------------------------------------------------

    As reflected in Table 6, future emissions of NOX and 
SO2 are expected to be below the ``attainment level'' 
emissions in 2007, while direct PM2.5 emissions are expected 
to increase slightly. 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,

[[Page 67129]]

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.\10\
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    \10\ Based on a limited review of data and emissions projections 
available to EPA from the Alabama 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.
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    Emissions of SO2 and NOX are projected to 
decline by 2.5 percent and 67.1 percent, respectively, from 2007 to 
2025. During the same period, emissions of PM2.5 are 
projected to increase slightly, by 18.6 percent. EPA does not believe 
that this 18.6 percent increase in PM2.5 emissions will 
threaten maintenance in the Area because even with this projected 
increase, as explained below, the overall projected design value 
remains well below the standard.
    Because the relationship between pollutant emissions and ambient 
air quality is different for each of the three pollutants, the changes 
in emissions for each pollutant must be weighted according to the air 
quality impact of each pollutant to obtain an appropriate indicator of 
the overall impact. For this purpose, GA EPD examined speciation data 
available from the EPA Air Explorer Web site for 2007-2009 for 
Chattanooga monitor ID 47-065-4002. The 3-year average of this data 
suggests that ambient PM2.5 in Chattanooga consists of 
approximately 48.1 percent sulfate; 2.4 percent nitrate; 40.6 percent 
organic particulate matter (which consists of directly-emitted primary 
organic matter and atmospherically formed secondary organic aerosol); 5 
percent miscellaneous inorganic particulate matter; and 3.9 percent 
other types of particulate matter. Therefore, using a conservative 
assumption that all of the organic particulate matter is primary 
organic matter, the direct PM2.5 species make up 45.6 
percent of the total ambient PM2.5.
    GA EPD used a conservative approach that assumes the full ambient 
concentration of organic particulate matter plus miscellaneous 
inorganic particulate matter will vary in accordance with changes in 
total nonattainment area emissions of direct PM2.5. This 
analysis thus assumes that the direct PM2.5 component of 
ambient PM2.5 will increase by the 18.6 percent projected 
increase in direct PM2.5 emissions for the Georgia portion 
of the Chattanooga TN-GA Area. The baseline concentration is 
conservatively assumed to be 15.0 [mu]g/m\3\, and direct 
PM2.5 is estimated to contribute 45.6 percent, or 6.84 
[mu]g/m\3\, of that value. Thus, an 18.6 percent increase in the 6.84 
[mu]g/m\3\ of the direct PM2.5 component would suggest a 
resulting 1.27 [mu]g/m\3\ increase in the ambient PM2.5 
concentration.
    EPA believes that the projected increase in direct PM2.5 
emissions will be overcompensated by a significant projected decrease 
in sulfate and nitrate emissions. As shown in Table 1, above, the 
emissions reductions that have already occurred have brought the 
PM2.5 design value for the Chattanooga TN-GA Area down to 
11.7 [mu]g/m\3\, based on 2008-2010 data. Therefore, the 1.27 [mu]g/
m\3\ increase in the components associated with direct PM2.5 
would not be expected to yield concentrations above the standard. The 
emissions reductions in SO2 and NOX projected by 
Georgia are due, in part, to the federal mobile source rules described 
in section V of this notice, and EPA believes that the State's 
projections are reasonable. In EPA's Regulatory Impact Analysis (RIA) 
entitled ``Control of Air Pollution from New Motor Vehicles: Tier 2 
Motor Vehicle Emissions Standards and Gasoline Sulfur Control 
Requirements released December 1999,'' \11\ EPA projected that 
implementation of the Tier 2/Low Sulfur rule would immediately and 
substantially reduce SOX emissions from cars and trucks once 
its fuel sulfur provisions began to take effect in 2004. EPA estimated 
that 90 percent of light-duty SOX emissions would be reduced 
when fuel with 30 ppm of sulfur was introduced into the market in 2006. 
EPA noted that SOX emission reductions would also occur from 
heavy-duty gasoline vehicles and motorcycles due to the reduced sulfur 
content in fuel. In the RIA, EPA estimated that the reductions would be 
approximately 10,000 tpy in 2005, growing to 16,000 tons by 2030. In 
addition, the Agency anticipated that emissions from all gasoline-
powered nonroad equipment would be reduced due to reduced sulfur 
content in fuel, by approximately 25,000 tpy between 2005 and 2020. EPA 
expects additional reductions in SO2 and NOX 
emissions from mobile sources as a result of the Tier 3 vehicle 
standards that will take effect in 2017 and reduce both tailpipe and 
evaporative emissions from passenger cars, light-duty trucks, medium-
duty passenger vehicles, and some heavy-duty vehicles. See 79 FR 23414 
(April 28, 2014). Georgia's projections of mobile source emissions 
through 2025 did not include the emissions reductions expected from the 
implementation of the Tier 3 standards, and therefore, likely 
underestimate the mobile source emissions reductions in NOX 
and SO2 expected from 2017 through 2025 in the Georgia 
portion of the Chattanooga TN-GA Area.
---------------------------------------------------------------------------

    \11\ EPA's RIA entitled ``Control of Air Pollution from New 
Motor Vehicles: Tier 2 Motor Vehicle Emissions Standards and 
Gasoline Sulfur Control Requirements released December 1999 can be 
found under EPA document number, EPA420-R-99-023.
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    A maintenance plan requires the state to show that projected future 
year overall emissions will not exceed the level of emissions which led 
the Area to attain the NAAQS. For the reasons discussed above, EPA 
agrees that Georgia'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 currently one monitor measuring ambient PM2.5 
in the Georgia portion of the Chattanooga TN-GA Area. GA EPD has 
committed to continue operation of the monitor in the Georgia portion 
of the Chattanooga TN-GA Area in compliance with 40 CFR part 58 and has 
thus addressed the requirement for monitoring. EPA approved Georgia's 
2013 monitoring plan on November 25, 2013.
4. Verification of Continued Attainment
    GA EPD has the legal authority to enforce and implement the 
requirements of the Georgia portion of the Chattanooga TN-GA Area 1997 
Annual PM2.5 maintenance plan. This includes the authority 
to adopt, implement, and enforce any subsequent emissions control 
contingency measures determined to be necessary to correct future 
PM2.5 attainment problems.
    GA EPD will track the progress of the maintenance plan by 
performing future reviews of triennial emission inventories for the 
Georgia 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, GA EPD 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 GA EPD will re-
project emissions for the Georgia 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

[[Page 67130]]

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 GA EPD. 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. GA EPD will use actual ambient monitoring data to determine 
whether a trigger event has occurred and when contingency measures 
should be implemented.
    Georgia has identified a Tier 1 trigger as occurring when any of 
the following conditions occurs, as described in the State's submittal 
for the Georgia portion of the Chattanooga TN-GA Area:
     The previous calendar year's annual average 
PM2.5 concentration exceeds the standard by 1.5 [micro]g/
m\3\ or more;
     The annual mean PM2.5 concentration in each of 
the previous two consecutive calendar years exceeds the NAAQS by 0.5 
[micro]g/m\3\ or more;
     The total maintenance area SO2 emissions in the 
most recent NEI exceeds the corresponding attainment-year inventory by 
more than 30.0 percent;
     The total maintenance area PM2.5 emissions in 
the most recent NEI exceed the corresponding attainment-year inventory 
by more than 30.0 percent.
    GA EPD will evaluate a Tier I condition, if it occurs, as 
expeditiously as practicable to determine the causes of the ambient 
PM2.5 or emissions inventory increase and to determine if a 
Tier II condition is likely to occur. A Tier II trigger will be 
activated when any violation of the Annual PM2.5 NAAQS at 
any federal reference method (FRM) monitor in the Georgia portion of 
the Chattanooga TN-GA maintenance area is recorded, based on quality-
assured monitoring data. In this event, GA EPD will conduct a 
comprehensive study to determine the cause of the ambient 
PM2.5 increase and to determine if the increase is likely to 
continue and will implement any required measures as expeditiously as 
practicable, taking into consideration the ease of implementation and 
the technical and economic feasibility of selected measures.
    The comprehensive study will be completed and submitted to EPA as 
expeditiously as practical but no later than nine months after the Tier 
I or Tier II trigger is activated, and the appropriate corrective 
measures will be adopted and implemented within 18 to 24 months after 
the trigger occurs. If the study determines that additional measures 
are required, the State will adopt rules no later than 18 months 
following the date that the trigger is activated.\12\ The comprehensive 
measures will be selected from the following types of measures or from 
any other measure deemed appropriate and effective at the time the 
selection is made by GA EPD:
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    \12\ In a September 23, 2013, letter to EPA, the State 
reaffirmed its commitment to address and correct any violation of 
the 1997 Annual PM2.5 NAAQS as expeditiously as 
practicable and no later than 24 months from the trigger activation.
---------------------------------------------------------------------------

     RACM for sources of SO2 and PM2.5;
     Reasonably Available Control Technologies (RACT) for point 
sources of SO2 and PM2.5;
     Expansion of RACM/RACT to areas of transport within the 
State;
     Mobile source measures; and
     Additional SO2 and/or PM2.5 
reduction measures yet to be identified.
    In addition to the triggers indicated above, Georgia will monitor 
regional emissions through the CERR and AERR and compare them to the 
projected inventories and the attainment year inventory. In the 
September 14, 2012, submittal, the State acknowledges that the 
contingency plan requires the implementation of all measures contained 
in the SIP for the Area prior to redesignation. The State also notes 
that these measures are currently in effect and may be evaluated by the 
State to determine if they are adequate or up-to-date.
    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 GA EPD for the Georgia portion of the Chattanooga 
TN-GA Area meets the requirements of section 175A of the CAA and 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 Georgia 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 Georgia 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 Georgia 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 Georgia 
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

[[Page 67131]]

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 Georgia's redesignation request for the Georgia 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 Georgia 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'').\13\ In this case, at the time that Georgia submitted its 
redesignation request on September 14, 2012, requirements under subpart 
4 were not due, and indeed, were not yet known to apply.
---------------------------------------------------------------------------

    \13\ 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 Georgia 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.
    In the context of this redesignation, the timing and nature of the 
Court's January 4, 2013, decision in NRDC v. EPA compound the 
consequences of imposing requirements that come due after the 
redesignation request is submitted. The State submitted its 
redesignation request on September 14, 2012, but the Court did not 
issue its decision remanding EPA's 1997 PM2.5 implementation 
rule concerning the applicability of the provisions of subpart 4 until 
January 2013.
    To require the State's fully-completed and pending redesignation 
request to comply now with requirements of subpart 4 that the Court 
announced only in January 2013 would be to give retroactive effect to 
such requirements when the State had no notice that it was required to 
meet them. The D.C. Circuit recognized the inequity of this type of 
retroactive impact in Sierra Club v. Whitman, 285 F.3d 63 (D.C. Cir. 
2002),\14\

[[Page 67132]]

where it upheld the District Court's ruling refusing to make 
retroactive EPA's determination that the St. Louis area did not meet 
its attainment deadline. In that case, petitioners urged the Court to 
make EPA's nonattainment determination effective as of the date that 
the statute required, rather than the later date on which EPA actually 
made the determination. The Court rejected this view, stating that 
applying it ``would likely impose large costs on States, which would 
face fines and suits for not implementing air pollution prevention 
plans . . . even though they were not on notice at the time.'' Id. at 
68. Similarly, it would be unreasonable to penalize the State of 
Georgia by rejecting its redesignation request for an area that is 
already attaining the 1997 PM2.5 standard and that met all 
applicable requirements known to be in effect at the time of the 
request. For EPA now to reject the redesignation request solely because 
the state did not expressly address subpart 4 requirements of which it 
had no notice would inflict the same unfairness condemned by the Court 
in Sierra Club v. Whitman.
---------------------------------------------------------------------------

    \14\ Sierra Club v. Whitman was discussed and distinguished in a 
recent D.C. Circuit decision that addressed retroactivity in a quite 
different context, where, unlike the situation here, EPA sought to 
give its regulations retroactive effect. National Petrochemical and 
Refiners Ass'n v. EPA. 630 F.3d 145, 163 (D.C. Cir. 2010), rehearing 
denied 643 F.3d 958 (D.C. Cir. 2011), cert denied 132 S. Ct. 571 
(2011).
---------------------------------------------------------------------------

d. Subpart 4 Requirements and the Georgia 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 
Georgia portion of the Chattanooga TN-GA Area still qualifies for 
redesignation to attainment. As explained below, EPA believes that the 
redesignation request for the Georgia 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 Georgia 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 Georgia 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 \15\ 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.\16\ 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 PM10 
requirements.'' See 57 FR 13538. The subpart 1 requirements include, 
among other things, provisions for attainment demonstrations, RACM RFP, 
emissions inventories, and contingency measures.
---------------------------------------------------------------------------

    \15\ PM10 refers to particles nominally 10 
micrometers in diameter or smaller.
    \16\ See ``State Implementation Plans; General Preamble for the 
Implementation of Title I of the Clear 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, EPA is 
considering the Georgia 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 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.\17\ 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).
---------------------------------------------------------------------------

    \17\ 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,\18\ 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.
---------------------------------------------------------------------------

    \18\ 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 \19\ 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.
---------------------------------------------------------------------------

    \19\ 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.
---------------------------------------------------------------------------

    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.
    Thus, EPA is proposing to conclude that the requirements to submit 
an attainment demonstration under 189(a)(1)(B), a RACM determination

[[Page 67133]]

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 Georgia 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.\20\ Under subpart 1 and EPA's prior 
implementation rule, all major stationary sources of PM2.5 
precursors 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.
---------------------------------------------------------------------------

    \20\ 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 Georgia 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.\21\ 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.
---------------------------------------------------------------------------

    \21\ 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

[[Page 67134]]

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.\22\ Courts have upheld this approach to the requirements of 
subpart 4 for PM10.\23\ 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 Georgia's request for redesignation of the Georgia 
portion of the Chattanooga TN-GA Area. In the context of a 
redesignation, Georgia has shown that the Chattanooga TN-GA Area 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 Georgia portion of the Chattanooga TN-GA Area to 
attainment for the 1997 Annual PM2.5 NAAQS at this time. In 
sum, even if Georgia were required to address precursors for Georgia 
portion of the Chattanooga TN-GA Area under subpart 4 rather than under 
subpart 1, EPA would still conclude that the area had met all 
applicable requirements for purposes of redesignation in accordance 
with section 107(d)(3(E)(ii) and (v).
---------------------------------------------------------------------------

    \22\ 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).
    \23\ 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 Georgia 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 Georgia and 
supporting information, EPA believes that the maintenance plan for the 
Georgia 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, 
as shown in table 7 below, VOC emissions are projected to decrease by 
over 2,000 tpy by 2020, and ammonia emissions are projected to increase 
only slightly. 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 Georgia Portion of the Chattanooga TN-GA
                                Area \24\
------------------------------------------------------------------------
                                          VOC               Ammonia
                                 ---------------------------------------
          Source sector                         Net                 Net
                                  2007  2020  change  2007  2020  change
------------------------------------------------------------------------
Nonpoint........................  2,26  2,24  -17.62  2,03  2,35  317.48
                                  5.68  8.06          5.25  2.73
Nonroad.........................  634.  357.  -277.1  0.5   0.63  0.13
                                   32    18      4
Onroad..........................  2,62  859.  -1,763  80.4  42.0  -38.40
                                  2.3    26    .04      5     5
Point...........................  45.6  45.6  -0.04     0     0      0
                                    6     2
                                 ---------------------------------------
    Total.......................  5,56  3,51  -2,057  2,11  2,39  279.21
                                  7.96  0.12   .84    6.20  5.41
------------------------------------------------------------------------

     
---------------------------------------------------------------------------

    \24\ These emissions estimates were taken from the emissions 
inventories developed for the RIA for the 2012 PM2.5 
NAAQS.
---------------------------------------------------------------------------

    Georgia's maintenance plan shows that emissions of SO2 
and NOX are projected to decrease over the maintenance 
period in the Georgia portion of the Chattanooga TN-GA Area by 10 tpy 
and 3,676 tpy, respectively, while direct PM2.5 emissions 
are projected to increase by 323 tpy. See Table 6, above. In addition, 
emissions inventories used

[[Page 67135]]

in the RIA for the 2012 PM2.5 NAAQS \25\ show that VOC 
emissions are projected to decrease by 2,057.84 tpy and that ammonia 
emissions are projected to increase by 279.21 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 and NOX 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.
---------------------------------------------------------------------------

    \25\ 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 [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 Georgia 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 Georgia 
portion of the Chattanooga TN-GA Area to attainment for the 1997 Annual 
PM2.5 NAAQS.

VII. What is EPA's analysis of Georgia's proposed NOX and 
PM2.5 MVEBs for the Georgia 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 for nonattainment areas. 
These control strategy SIPs (including RFP and attainment 
demonstration) and maintenance plans create MVEBs for criteria 
pollutants and/or their precursors to address pollution from cars and 
trucks. Per 40 CFR part 93, a MVEB must be established for the last 
year of the maintenance plan. A state may adopt MVEBs for other years 
as well. The MVEBs 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 MVEBs serves as a 
ceiling on emissions from an area's planned transportation system. The 
MVEBs concept is further explained in the preamble to the November 24, 
1993, Transportation Conformity Rule. See 58 FR 62188. The preamble 
also describes how to establish the MVEBs in the SIP and how to revise 
the MVEBs.
    After interagency consultation with the transportation partners for 
the Georgia portion of the Chattanooga TN-GA Area, Georgia has elected 
to develop MVEBs for NOX and PM2.5 for the 
Georgia portion of the Chattanooga TN-GA Area. Georgia has developed 
these MVEBs, as required, for the last year of its maintenance plan, 
2025. The MVEBs reflect the total on-road emissions for 2025, plus an 
allocation from the available NOX and PM2.5 
safety margin. Under 40 CFR 93.101, the term ``safety margin'' is the 
difference between the attainment level (from all sources) and the 
projected level of emissions (from all sources) in the maintenance 
plan. The safety margin can be allocated to the transportation sector; 
however, the total emissions must remain below the attainment level. 
The NOX and PM2.5 MVEBs and allocation from the 
safety margin were developed in consultation with the transportation 
partners and were added to account for uncertainties in population 
growth, changes in model vehicle miles traveled and new emission factor 
models. The NOX and PM2.5 MVEBs for the Georgia 
portion of the Chattanooga TN-GA Area are defined in Table 8 below.

    Table 8--PM2.5 and NOX MVEBs (tpy) for the Georgia Portion of the
                         Chattanooga TN-GA Area
------------------------------------------------------------------------
                                                      PM2.5       NOX
------------------------------------------------------------------------
2025 Mobile Emissions............................       36       1,021.8
2025 Safety Margin Allocated.....................        8.2       364.6
                                                  ----------------------
  2025 Total Mobile Budget.......................       44.2     1,386.5
------------------------------------------------------------------------

    In an effort to accommodate future variations in Travel Demand 
Models (TDM) and the vehicle miles traveled forecast when no change to 
the network is planned, GA EPD consulted with the interagency 
consultation group, including EPA, to determine a reasonable approach 
to address this variation. The projected 2025 on-road motor vehicle 
emissions for direct PM2.5 and NOX are 36 tpy and 
1,021.8 tpy, respectively. On-road emissions of SO2

[[Page 67136]]

are considered de-minimus; therefore, no budget for SO2 is 
required.\26\
---------------------------------------------------------------------------

    \26\ 70 FR 24280, 24283 (May 6, 2005) (``While speciated air 
quality data show that sulfate is a relatively significant component 
(e.g., ranging from nine to 40 percent) of PM2.5 mass in 
all regions of the country, emissions inventory data and projections 
show that on-road emissions of SOX constitute a ``de 
minimis'' (i.e., extremely small) portion of total SOX 
emissions.'').
---------------------------------------------------------------------------

    A safety margin is necessary to accommodate the variabilities, or 
worst-case scenarios that can occur due to future planning assumptions. 
The worst-case daily motor vehicle emissions projection for 
PM2.5 is 22.8 percent above the projected 2025 on-road 
emissions. In a worst-case scenario, the needed annual safety margin 
for the PM2.5 MVEB would be 8.2 tpy resulting in an overall 
MVEB of 44.2 tpy. The worst-case daily motor vehicle emissions 
projection for NOX is 35.7 percent above the projected 2025 
on-road emissions. In a worst-case scenario, the required annual safety 
margin for the NOX MVEB would be 364.6 tpy resulting in an 
overall MVEB of 1,386.5 tpy.
    Through this rulemaking, EPA is proposing to approve the MVEBs for 
NOX and PM2.5 for 2025 for the Georgia 
portion of the Chattanooga TN-GA Area because EPA has determined that 
the Area maintains the 1997 Annual PM2.5 NAAQS with the 
emissions at the levels of the budgets. Once the MVEBs for the Georgia 
portion of the Chattanooga TN-GA Area are approved or found adequate 
(whichever is completed first), they must be used for future conformity 
determinations. After thorough review, EPA has determined that the 
budgets meet the adequacy criteria, as outlined in 40 CFR 93.118(e)(4). 
Therefore, EPA is proposing to approve the budgets because they are 
consistent with maintenance of the 1997 Annual PM2.5 NAAQS 
through 2025.

VIII. What is the status of EPA's adequacy determination for the 
proposed NOX and PM2.5 MVEBs for 2025 for the 
Georgia portion of the Chattanooga TN-GA Area?

    When reviewing submitted ``control strategy'' SIPs or maintenance 
plans containing MVEB, EPA may affirmatively find the MVEB contained 
therein adequate for use in determining transportation conformity. Once 
EPA affirmatively finds the submitted MVEB is adequate for 
transportation conformity purposes, that MVEBs must be used by state 
and federal agencies in determining whether proposed transportation 
projects conform to the SIP as required by section 176(c) of the CAA.
    EPA's substantive criteria for determining adequacy of MVEBs 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 MVEBs for transportation 
conformity purposes was initially outlined in EPA's May 14, 1999, 
guidance entitled ``Conformity Guidance on Implementation of March 2, 
1999, Conformity Court Decision.'' EPA adopted regulations to codify 
the adequacy process in rulemaking entitled 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''; 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''; June 30, 2003 (68 FR 38974, 
38984).
    As discussed earlier, Georgia's maintenance plan submission 
includes NOX and PM2.5 MVEBs for the Georgia 
portion of the Chattanooga TN-GA Area for 2025, the last year of the 
maintenance plan. EPA reviewed the NOX and PM2.5 
MVEBs through the adequacy process, and the adequacy of the MVEBs, was 
open for public comment on EPA's adequacy Web site on March 4, 2013, 
found at: http://www.epa.gov/otaq/stateresources/transconf/currsips.htm. The EPA public comment period on adequacy for the MVEBs 
for 2025 for the Georgia portion of the Chattanooga TN-GA Area closed 
on April 3, 2013. EPA did not receive any comments on the adequacy of 
the MVEBs, nor did EPA receive any requests for the SIP submittal.
    EPA intends to make its determination on the adequacy of the 2025 
MVEBs for the Georgia portion of the Chattanooga TN-GA Area for 
transportation conformity purposes in the near future by completing the 
adequacy process that was started on March 4, 2013. After EPA finds the 
2025 MVEBs adequate or takes final action to approve them into the 
Georgia SIP, the new MVEBs for NOX and PM2.5 must 
be used for future transportation conformity determinations. For 
required regional emissions analysis years that involve 2025 or beyond, 
the applicable budgets will be the new 2025 MVEBs established in the 
maintenance plan.

IX. Proposed Actions on the Redesignation Request and Maintenance Plan 
SIP Revisions Including Approval of the NOX and 
PM2.5 MVEBs for 2025 for the Georgia Portion of the 
Chattanooga TN-GA Area

    On May 31, 2011, EPA determined that the Chattanooga TN-GA Area was 
attaining the 1997 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 
Georgia 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 Georgia's redesignation request for the 
Georgia portion of the Chattanooga TN-GA Area.
    Second, EPA is proposing to approve the maintenance plan for the 
Georgia portion of the Chattanooga TN-GA Area, including the 
PM2.5 and NOX MVEBs for 2025 submitted by Georgia 
into the State's SIP (under section 175A). The maintenance plan 
demonstrates that the Area will continue to maintain the 1997 Annual 
PM2.5 NAAQS, and the budgets meet all of the adequacy 
criteria contained in 40 CFR 93.118(e)(4) and (5). Further, as part of 
today's action, EPA is describing the status of its adequacy 
determination for transportation conformity purposes for the 
PM2.5 and NOX MVEBs for 2025 under 40 CFR 
93.118(f)(1). Within 24 months from the effective date of EPA's 
adequacy determination for the MVEBs or the effective date for the 
final rule approving the MVEBs into the Georgia SIP, whichever is 
earlier, the transportation partners will need to demonstrate 
conformity to the new NOX and PM2.5 MVEBs 
pursuant to 40 CFR 93.104(e).
    If finalized, approval of the redesignation request would change 
the official designation of Georgia portion of the Chattanooga TN-GA 
Area for the 1997 Annual PM2.5 NAAQS, found at 40 CFR part 
81 from nonattainment to attainment.

[[Page 67137]]

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 Georgia's redesignation request would change the legal designation 
of Catoosa and Walker Counties in Georgia for the 1997 Annual 
PM2.5 NAAQS, found at 40 CFR part 81, from nonattainment to 
attainment. Approval of GA EPD's request would also incorporate a plan 
for maintaining the 1997 Annual PM2.5 NAAQS in the 
Chattanooga TN-GA Area through 2025 into the Georgia SIP. The 
maintenance plan includes contingency measures to remedy any future 
violations of the 1997 Annual PM2.5 NAAQS and procedures for 
evaluation of potential violations. The maintenance plan also includes 
NOX and PM2.5 MVEBs for the Georgia portion of 
the Chattanooga TN-GA Area. Additionally, EPA is notifying the public 
of the status of its adequacy determination for the NOX and 
PM2.5 MVEBs for 2025 under 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 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).
    In addition, this proposed rule does not have tribal implications 
as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), 
because the SIP is not approved to apply in Indian country located in 
Georgia, and EPA notes that it will not impose substantial direct costs 
on tribal governments or preempt tribal law.

List of Subjects in 40 CFR Part 52

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

40 CFR Part 81

    Environmental protection, Air pollution control.

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

    Dated: November 3, 2014.
V. Anne Heard
Acting Regional Administrator, Region 4.
[FR Doc. 2014-26735 Filed 11-10-14; 8:45 am]
BILLING CODE 6560-50-P