[Federal Register Volume 81, Number 6 (Monday, January 11, 2016)]
[Proposed Rules]
[Pages 1144-1162]
[FR Doc No: 2015-33196]

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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R04-OAR-2013-0084; FRL-9940-88-Region 4]

Air Plan Approval and Air Quality Designation; GA; Redesignation
of the Atlanta, GA, 1997 Annual PM2.5 Nonattainment Area to
Attainment

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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

SUMMARY: On August 30, 2012, the Georgia Department of Natural
Resources, through the Georgia Environmental Protection Division (GA
EPD), submitted a request for the Environmental Protection Agency (EPA)
to redesignate the Atlanta, Georgia, fine particulate matter
(PM2.5) nonattainment area (hereafter referred to as the
``Atlanta 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 Atlanta Area. EPA is proposing to determine
that the Atlanta Area is continuing to attain the 1997 Annual
PM2.5 NAAQS; to approve Georgia's plan for maintaining the
1997 Annual PM2.5 NAAQS in the Atlanta Area (maintenance
plan), including the associated motor vehicle emission budgets (MVEBs)
for nitrogen oxides (NOX) and PM2.5 for the year
2024, into Georgia's SIP; and to redesignate the Atlanta Area to
attainment for the 1997 Annual PM2.5 NAAQS. EPA is also
notifying the public of the status of EPA's adequacy determination for
the Atlanta Area.

DATES: Comments must be received on or before February 1, 2016.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2013-0084, by one of the following methods:
    1. www.regulations.gov: Follow the on-line instructions for
submitting comments.
    2. Email<EMAIL_ADDRESS>    3. Fax:<PHONE_NUMBER>.
    4. Mail: EPA-R04-OAR-2013-0084, Air Regulatory Management Section,
Air Planning and Implementation Branch, Air, Pesticides and Toxics
Management Division, U.S. Environmental Protection Agency, Region 4, 61
Forsyth Street SW., Atlanta, Georgia 30303-8960.
    5. Hand Delivery or Courier: Ms. Lynorae Benjamin, Chief, Air
Regulatory Management Section, Air Planning and Implementation Branch,
Air, Pesticides and Toxics Management Division, U.S. Environmental
Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia
30303-8960. 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-
2013-0084. 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 may not be 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 Air Regulatory Management
Section, Air Planning and Implementation Branch, Air, Pesticides and
Toxics Management Division, U.S. Environmental Protection Agency,
Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960. 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: Joel Huey, Air Planning and
Implementation Branch, Air, Pesticides and Toxics Management Division,
U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW.,
Atlanta, Georgia 30303-8960. Joel Huey may be reached by phone at (404)
562-9104 or via electronic mail at<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Table of Contents

I. What are the actions EPA is proposing to take?
II. What is the background for EPA's proposed actions?
III. What are the criteria for redesignation?
IV. Why is EPA proposing these actions?

V. What is EPA's analysis of the request?
VI. What is 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 Atlanta Area?
VIII. What is the status of EPA's adequacy determination for the
proposed NOX and PM2.5 MVEBs for 2024 for the
Atlanta area?
IX. Proposed Actions on the Redesignation Request and Maintenance
Plan SIP Revisions Including Approval of the NOX and
PM2.5 MVEBs for 2024 for the Atlanta Area.
X. Statutory and Executive Order Reviews

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

    EPA is proposing to take the following three separate but related
actions, one of which involves multiple elements: (1) To determine that
the Atlanta Area is continuing to attain the 1997 Annual
PM2.5 NAAQS; (2) to approve Georgia's plan for maintaining
the 1997 Annual PM2.5 NAAQS for the Atlanta Area
(maintenance plan), including the associated MVEBs, into Georgia SIP;
and (3) to redesignate the Atlanta Area to attainment for the 1997
Annual PM2.5 NAAQS. EPA is also notifying the public of the
status of EPA's adequacy determination for the MVEBs for the Atlanta
Area. The Atlanta Area is comprised of twenty whole counties and two
partial counties in Georgia: Barrow, Bartow, Carroll, Cherokee,
Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton,
Gwinnett, Hall, Henry, Newton, Paulding, Rockdale, Spalding, Walton,
and portions of Heard and Putnam Counties. Today's proposed actions are
summarized below and described in great detail in this notice of
proposed rulemaking.
    EPA is making the preliminary determination that the Atlanta Area
is continuing to attain the 1997 Annual PM2.5 NAAQS based on
recent air quality data \1\ and proposing to approve Georgia's 1997
Annual PM2.5 NAAQS maintenance plan for the Atlanta Area
(such approval being one of the Clean Air Act (CAA or Act) criteria for
redesignation to attainment status). The maintenance plan is designed
to help keep the Atlanta Area in attainment for the 1997 Annual
PM2.5 NAAQS through 2024. As explained in Section V below,
EPA is also proposing to determine that attainment can be maintained
through 2025. The maintenance plan that EPA is proposing to approve
today includes on-road MVEBs for the mobile source contribution of
NOX and direct PM2.5 to the air quality problem
in the Atlanta Area for transportation conformity purposes. EPA is
proposing to approve the 2024 MVEBs for NOX and
PM2.5 for the Atlanta Area and incorporate them in to the
Georgia SIP.
---------------------------------------------------------------------------

    \1\ As discussed in section V below, this proposed determination
is also based on EPA's December 8, 2011, determination that the
Atlanta Area was attaining the standard at that time. 76 FR 76620.
---------------------------------------------------------------------------

    EPA also proposes to determine that the Atlanta Area has met the
requirements for redesignation under section 107(d)(3)(E) of the CAA.
Accordingly, in this action, EPA is proposing to approve a request to
change the legal designation of the Barrow, Bartow, Carroll, Cherokee,
Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton,
Gwinnett, Hall, Henry, Newton, Paulding, Rockdale, Spalding, Walton,
and portions of Heard and Putnam Counties in Georgia from nonattainment
to attainment for the 1997 Annual PM2.5 NAAQS.
    EPA is also notifying the public of the status of EPA's adequacy
process for the 2024 NOX and PM2.5 MVEBs for the
Atlanta Area. The Adequacy comment period began on February 21, 2013,
with EPA's posting of the availability of Georgia's submission on EPA's
Adequacy Web site (http://www.epa.gov/otaq/stateresources/transconf/currsips.htm#atlanta0221). The Adequacy comment period for these MVEBs
closed on March 25, 2013. No comments, adverse or otherwise, were
received through the Adequacy process. Please see section VIII of this
proposed rulemaking for further explanation of this process and for
more details on the MVEBs.
    In summary, today's notice of proposed rulemaking is in response to
Georgia's August 30, 2012, redesignation request and associated SIP
submission that address the specific issues summarized above and the
necessary elements for redesignation described in section 107(d)(3)(E)
of the CAA.

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

    Fine particle pollution can be emitted directly or formed
secondarily in the atmosphere.\2\ 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.
---------------------------------------------------------------------------

    \2\ 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 Atlanta 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.
---------------------------------------------------------------------------

    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.\3\ 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 [micro]g/m\3\
at all relevant monitoring sites in the subject area averaged over a 3-
year period.
---------------------------------------------------------------------------

    \3\ 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. Circuit) remanded that NAAQS to
EPA for further consideration. See American Farm Bureau Federation
and National Pork Producers Council, et al. v. EPA, 559 F.3d 512
(D.C. Cir. 2009). However, given that the 1997 and 2006 Annual NAAQS
are essentially identical, attainment of the 1997 Annual NAAQS would
also indicate attainment of the remanded 2006 Annual NAAQS.
---------------------------------------------------------------------------

    On January 5, 2005, and supplemented on April 14, 2005, EPA
designated the Atlanta 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
PM2.5 NAAQS established in 2006 and designated all counties
of the Atlanta Area as unclassifiable/attainment for that standard. See
74 FR 58688. 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. The November 13, 2009,

action also clarified that all counties of the Atlanta Area were
designated unclassifiable/attainment for the 1997 24-hour
PM2.5 NAAQS through the designations promulgated on January
5, 2005. Therefore, the Area is designated nonattainment for the 1997
Annual PM2.5 NAAQS, and today's action only addresses that
designation.
    All 1997 PM2.5 NAAQS areas were originally 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 Clean Air Fine Particle
Implementation Rule, codified at 40 CFR part 51, subpart Z, in which
the Agency provided guidance for state and tribal plans to implement
the 1997 PM2.5 NAAQS. 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 D.C. Circuit remanded the Clean Air Fine
Particle Implementation Rule and the final rule entitled
``Implementation of the New Source Review (NSR) Program for Particulate
Matter Less than 2.5 Micrometers (PM2.5)'' (73 FR 28321, May
16, 2008) (collectively, ``1997 PM2.5 Implementation
Rules'') to EPA on January 4, 2013, in Natural Resources Defense
Council v. EPA, 706 F.3d 428 (D.C. Cir. 2013). The Court found that EPA
erred in implementing the 1997 PM2.5 NAAQS pursuant to the
general implementation provisions of subpart 1 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 2008-2010 indicated no
violations of the 1997 PM2.5 NAAQS for the Atlanta Area. As
a result, on August 30, 2012, Georgia requested redesignation of the
Atlanta Area to attainment for the 1997 Annual PM2.5 NAAQS.
The redesignation request includes three years of ambient air quality
data, certified as quality-assured by the State of Georgia, for the
1997 Annual PM2.5 NAAQS for 2008-2010, indicating that the
1997 PM2.5 NAAQS had been achieved for the Atlanta Area.
Under the CAA, nonattainment areas may be redesignated to attainment if
sufficient 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
Atlanta Area's design value,\4\ based on data from 2008 through 2010,
is below 15.0 [micro]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 Atlanta Area can be attributed
to the reduction of pollutant emissions, as discussed in more detail in
Section V of this proposed rulemaking.
---------------------------------------------------------------------------

    \4\ Design values are the metrics that are compared to the NAAQS
levels to determine attainment. The annual design value is
calculated as the average of three consecutive annual means. See 40
CFR part 50, Appendix N.
---------------------------------------------------------------------------

III. What are the criteria for redesignation?

    The CAA provides the requirements for redesignating a nonattainment
area to attainment. Specifically, section 107(d)(3)(E) of the CAA
allows for redesignation provided the following criteria are met: (1)
The Administrator determines that the area has attained the applicable
NAAQS; (2) the Administrator has fully approved the applicable
implementation plan for the area under section 110(k); (3) the
Administrator determines that the improvement in air quality is due to
permanent and enforceable reductions in emissions resulting from
implementation of the applicable SIP and applicable Federal air
pollutant control regulations and other permanent and enforceable
reductions; (4) the Administrator has fully approved a maintenance plan
for the area as meeting the requirements of section 175A; and (5) the
state containing such area has met all requirements applicable to the
area under section 110 and part D of title I of the CAA.
    On April 16, 1992, EPA provided guidance on redesignation in the
General Preamble for the Implementation of title I of the CAA
Amendments of 1990 (57 FR 13498), and the Agency supplemented this
guidance on April 28, 1992 (57 FR 18070). EPA has provided further
guidance on processing redesignation requests in the following
documents:
    1. ``Procedures for Processing Requests to Redesignate Areas to
Attainment,'' Memorandum from John Calcagni, Director, Air Quality
Management Division, September 4, 1992 (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 August 30, 2012, the State of Georgia, through the GA EPD,
requested that EPA redesignate the Atlanta Area to attainment for the
1997 Annual PM2.5 NAAQS. EPA's evaluation indicates that the
Area has attained the 1997 PM2.5 NAAQS and meets the
requirements for redesignation set forth in section 107(d)(3)(E),
including the maintenance plan requirements under section 175A of the
CAA. As a result, EPA is proposing to take the three related actions
summarized in section I of this notice.

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

    As stated above, in accordance with the CAA, EPA proposes in
today's action to: (1) Make the determination that the Atlanta Area
continues to attain the 1997 Annual PM2.5 NAAQS; (2) approve
the 1997 Annual PM2.5 NAAQS maintenance plan for the Atlanta
Area, including the associated MVEBs, into the Georgia SIP as described
below; and (3) redesignate the Atlanta Area to attainment for the 1997
Annual PM2.5 NAAQS. The five redesignation criteria provided
under CAA section 107(d)(3)(E) are discussed in greater detail for the
Atlanta Area in the following paragraphs of this section.

Criteria (1)--The Atlanta Area Has Attained the 1997 Annual
PM2.5 NAAQS

    For redesignating a nonattainment area to attainment, the CAA
requires EPA to determine that the area has attained the applicable
NAAQS (CAA section 107(d)(3)(E)(i)). For PM2.5, an area may
be considered to be attaining the 1997 Annual PM2.5 NAAQS if
it meets the standards, as determined in accordance with 40 CFR 50.13
and Appendix N of part 50, based on three complete, consecutive
calendar years of quality-assured air quality monitoring data. To
attain 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 December 8, 2011, EPA determined that the Atlanta Area was
attaining the 1997 Annual PM2.5 NAAQS and that the Area had
attained the NAAQS by the applicable attainment date of April 5,
2010.\5\ See 76 FR 76620. For that action, EPA reviewed
PM2.5 monitoring data from monitoring stations in the
Atlanta Area for the 1997 Annual PM2.5 NAAQS for 2007
through 2010. Those data were quality-assured and recorded in AQS. For
today's proposed action, EPA has reviewed all PM2.5
monitoring data after 2010 from the seven PM2.5 monitoring
stations, and that data indicates that the Atlanta Area continues to
attain the 1997 Annual PM2.5 NAAQS.
---------------------------------------------------------------------------

    \5\ 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 (2008-2010) for the Atlanta 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 Atlanta Area. See 76 FR 76620 (December 8,
2011).
---------------------------------------------------------------------------

    As shown in Table 1 below, the monitors in the Atlanta Area that
have collected complete data since 2010 all have three-year average
PM2.5 concentrations (i.e., design values) that are in
attainment with the 1997 Annual PM2.5 NAAQS and are trending
downward overall. The most recent available design value is for 2014
and is based on the 3-year period 2012-2014. The Fire Station No. 8
monitor had incomplete data during the 3rd quarter of 2012 and is not
eligible for the high value data substitution test in 40 CFR part 50,
Appendix N. However, based upon the analysis described in the
monitoring Technical Support Document (TSD) located in the docket for
today's action, EPA has preliminarily determined that the upper end of
the probable range for the 2014 design value at the Fire Station No. 8
monitor (11.1 [micro]g/m\3\) is well below the NAAQS. On the basis of
this review, EPA has preliminarily concluded that the Atlanta Area
continues to meet the 1997 Annual PM2.5 NAAQS of 15.0
[micro]g/m\3\ for the period 2012-2014, the most recent 3-year period
of certified data availability.

            Table 1--Design Value Concentrations for the Atlanta Area for the 1997 Annual PM2.5 NAAQS
                                                  [[mu]g/m\3\]
----------------------------------------------------------------------------------------------------------------
                                                                       3-Year design values
            Location                 Site ID    ----------------------------------------------------------------
                                                  2008-2010    2009-2011    2010-2012    2011-2013    2012-2014
----------------------------------------------------------------------------------------------------------------
Georgia DOT....................     13-063-0091         12.9         12.6         12.3         11.1         10.3
GA National Guard..............     13-067-0003         12.3       * 11.7       * 11.3       * 10.4         10.0
Powder Springs ...............     13-067-0004       * 11.9       * 11.3         11.1           NA           NA
South DeKalb...................     13-089-0002         12.1         11.9         11.5         10.5          9.9
Police Dept. .................     13-089-2001         12.3       * 11.8       * 11.3           NA           NA
E. Rivers School .............     13-121-0032         12.3       * 11.8       * 11.3           NA           NA
Fire Station No. 8.............     13-121-0039       * 11.4         13.2         13.0       * 11.6       * 11.0
Gwinnett Tech..................     13-135-0002         12.1       * 11.6       * 11.2       * 10.1          9.5
Gainesville....................     13-139-0003         11.2         10.7         10.4          9.5          8.9
Yorkville......................     13-223-0003         11.0       * 10.6       * 10.3        * 9.3          8.7
----------------------------------------------------------------------------------------------------------------
* Data is incomplete.
 Monitor shut down at the end of 2012 in accordance the State's federally approved monitoring network plan.

    The most recent data indicate the Atlanta Area continues to attain
the 1997 Annual PM2.5 NAAQS beyond the submitted 3-year
attainment period of 2008-2010. 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 Atlanta 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 Atlanta Area under section 110 of the CAA (general SIP
requirements) and 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 Atlanta 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 (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 classification are the relevant measures to evaluate in reviewing a
redesignation request. The transport SIP submittal requirements, where
applicable, continue to apply to a state regardless of the designation
of any one particular area in the state. Thus, EPA does not believe
that the CAA's interstate transport requirements should be construed to
be applicable requirements for purposes of redesignation.
    In addition, EPA believes other section 110 elements that are
neither connected with nonattainment plan submissions nor linked with
an area's attainment status are not applicable requirements for
purposes of redesignation. The area will still be subject to these
requirements after the area is redesignated. The section 110 and part D
requirements which are linked with a particular area's designation and
classification are the relevant measures to evaluate in reviewing a
redesignation request. This approach is consistent with EPA's existing
policy on applicability (i.e., for redesignations) of conformity and
oxygenated fuels requirements, as well as with section 184 ozone
transport requirements. See Reading, Pennsylvania, proposed and final
rulemakings (61 FR 53174-53176, October 10, 1996), (62 FR 24826, May 7,
1997); Cleveland-Akron-Loraine, Ohio, final rulemaking (61 FR 20458,
May 7, 1996); and Tampa, Florida, final rulemaking at (60 FR 62748,
December 7, 1995). See also the discussion on this issue in the
Cincinnati, Ohio, redesignation (65 FR 37890, June 19, 2000) and in the
Pittsburgh, Pennsylvania, redesignation (66 FR 50399, October 19,
2001).
    In any event, 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 statewide
requirements that are not linked to the PM2.5 nonattainment
status of the Atlanta Area, and thus, as stated above, EPA does not
believe these section 110 elements to be applicable for purposes of
this 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 Atlanta 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 Atlanta 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
sections 172 and 176 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. However,
pursuant to 40 CFR 51.1004(c), EPA's final determination that the
Atlanta Area is attaining the PM2.5 standard suspended
Georgia's obligation to submit most of the attainment planning
requirements that would otherwise apply.
    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 (RFP) 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 RFP, RACM, and
contingency measures under section 172(c)(9).\6\ 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).
---------------------------------------------------------------------------

    \6\ 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 Atlanta 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. The 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 Atlanta Area has monitored attainment of
the 1997 Annual PM2.5 NAAQS. In addition, because the
Atlanta 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 for approval a comprehensive,
accurate, and current inventory of actual emissions. On March 1, 2012,
EPA approved Georgia's 2002 base-year emissions inventory for the
Atlanta 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) 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
Atlanta 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 Atlanta 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 \7\ 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). Nonetheless, Georgia has an approved
conformity SIP for the Atlanta Area. See 77 FR 35866 (June 15, 2012).
---------------------------------------------------------------------------

    \7\ 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 Atlanta Area has
satisfied all applicable requirements for purposes of redesignation
under section 110 and part D of the CAA.
b. The Atlanta Area Has a Fully Approved Applicable SIP Under Section
110(k) of the CAA
    EPA has fully approved the applicable Georgia SIP for the Atlanta
Area for the 1997 Annual PM2.5 NAAQS 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 Atlanta Area (e.g., 77 FR 65125
(October 25, 2012)).
    As indicated above, EPA believes that the section 110 elements that
are neither connected with nonattainment plan submissions nor linked to
the area's nonattainment status are not applicable requirements for
purposes of redesignation. EPA has approved all part D requirements
applicable for purposes of this redesignation.

Criteria (3)--The Air Quality Improvement in the Atlanta 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 has preliminarily determined that
Georgia has demonstrated that the observed air quality improvement in
the Atlanta Area is due to permanent and enforceable reductions in
emissions resulting from implementation of the SIP and Federal
measures.
    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. A few
non-regulatory measures also result in emission reductions. The Federal
measures that have been implemented include:
    Tier 2 vehicle standards and low-sulfur gasoline. Implementation of
the Tier 2 vehicle standards began in 2004, and as newer, cleaner cars
enter the national fleet, these standards continue to significantly
reduce NOX emissions. The standards require all classes of
passenger vehicles in any manufacturer's fleet to meet an average
standard of 0.07 grams of NOX per mile. In addition,
starting in January of 2006, the Tier 2 rule reduced the allowable
sulfur content of gasoline to 30 parts per million (ppm). Most gasoline
sold prior to this had a sulfur content of approximately 300 ppm. EPA
expects

that these standards will reduce NOX emissions from vehicles
by approximately 74 percent by 2030, translating to nearly 3 million
tons annually by 2030.
    Heavy-duty gasoline and diesel highway vehicle standards & ultra
low-sulfur diesel rule. On October 6, 2000, 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. On January 18, 2001, EPA promulgated a second phase of standards
and testing procedures which began in 2007 to reduce particulate matter
emissions from heavy-duty highway engines and reduced the maximum
highway diesel fuel sulfur content from 500 ppm to 15 ppm. See 66 FR
5002. The total program should achieve a 90 percent reduction in PM
emissions and a 95 percent reduction in NOX emissions for
new engines using low-sulfur diesel, compared to existing engines using
higher-content sulfur diesel. EPA expects that this rule will reduce
NOX emissions by 2.6 million tons by 2030 when the heavy-
duty vehicle fleet is completely replaced with newer heavy-duty
vehicles that comply with these emission standards.
    Non-road, large spark-ignition engines and recreational engines
standards. 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 help
reduce ambient concentrations of PM2.5.
    Large non-road diesel engine standards. This rule, which applies to
diesel engines used in industries such as construction, agriculture,
and mining, was promulgated in 2004 and fully phased in by 2014. This
rule reduced allowable non-road diesel fuel sulfur levels from
approximately 3,000 ppm to 500 ppm in 2007 and further reduced those
levels to 15 ppm starting in 2010 (a 99 percent reduction). This rule
also achieved significant reductions of up to 90 percent for
NOX and particulate matter emissions nationwide.
    NOX SIP Call. On October 27, 1998 (63 FR 57356), EPA issued the
NOX SIP Call requiring the District of Columbia and 22
states to reduce emissions of NOX, a precursor to ozone and
PM2.5 pollution, and providing a mechanism (the
NOX Budget Trading Program) that states could use to achieve
those reductions. Affected states were required to comply with Phase I
of the SIP Call beginning in 2004 and Phase II beginning in 2007. By
the end of 2008, ozone season NOX emissions from sources
subject to the NOX SIP Call dropped by 62 percent from 2000
emissions levels. All NOX SIP Call states have SIPs that
currently satisfy their obligations under the NOX SIP Call,
and EPA will continue to enforce the requirements of the NOX
SIP Call.
    CAIR and CSAPR. In its redesignation request and maintenance plan,
the State identified the Clean Air Interstate Rule (CAIR) as a
permanent and enforceable measure that contributed to attainment in the
Atlanta Area. Moreover, by 2007, the beginning of the attainment time
period identified by Georgia, CAIR had been promulgated and was
achieving emission reductions. CAIR created regional cap-and-trade
programs to reduce SO2 and NOX emissions in 27
eastern states, including Georgia, that contributed to downwind
nonattainment or interfered with maintenance of the 1997 8-hour ozone
NAAQS and the 1997 PM2.5 NAAQS. See 70 FR 25162 (May 12,
2005).
    In 2007 the State promulgated Georgia Rules 391-3-1-.02(2)(sss)--
``Multipollutant Rule'' (Rule (sss)) and 391-3-1-.02(2)(uuu)--
``SO2 Emissions from Electric Steam Utility Steam Generating
Units'' (Rule (uuu)) in response to CAIR. Rule (sss) requires the
installation and operation of flue gas desulfurization (FGD) to control
SO2 emissions and selective catalytic reduction (SCR) to
control NOX emissions on the majority of the coal-fired
electric generating units (EGUs) in Georgia, and Rule (uuu) requires a
95 percent reduction in SO2 emissions from those EGUs. Thus,
Rules (sss) and (uuu) act as companion rules for the reduction of
SO2 emissions, with Rule (sss) requiring control equipment
installation and Rule (uuu) imposing SO2 emission
limitations. Georgia designed Rules (sss) and (uuu) to require
emissions reductions consistent with achieving the reductions mandated
by CAIR's original compliance schedule beginning in 2009. The
implementation dates for Rules (sss) and (uuu) are phased-in across the
covered EGUs, starting on December 31, 2008, for Rule (sss) and January
1, 2010, for Rule (uuu).\8\ By installing and operating FGD and SCR
controls in accordance with Rule (sss), Georgia EGUs also met the
requirements of CAIR.
---------------------------------------------------------------------------

    \8\ Rule (sss) established the following 2008-2010 deadlines for
FGD operation: December 31, 2008, at Plant Bowen Units 3 and 4,
Plant Hammond Units 1 through 4, Plant Wansley Unit 1, and Plant
Yates Unit 1; June 1, 2009, at Plant Bowen Unit 2; December 31,
2009, at Plant Wansley Unit 2; and June 1, 2010, at Plant Bowen Unit
1. The Rule established the following 2008-2010 deadlines for SCR
operation: December 31, 2008, at Plant Bowen Units 3 and 4, Plant
Hammond Unit 4, and Plant Wansley Unit 1; June 1, 2009, at Plant
Bowen Unit 2; December 31, 2009, at Plant Wansley Unit 2; and June
1, 2010, at Plant Bowen Unit 1. Plants Bowen and Wansley are located
in the Atlanta Area, and Plant Hammond is located in Floyd County,
Georgia, which is adjacent to the northwestern portion of the
Atlanta Area.
---------------------------------------------------------------------------

    In 2008 the United States Court of Appeals for the District of
Columbia Circuit (D.C. Circuit) initially vacated CAIR, North Carolina
v. EPA, 531 F.3d 896 (D.C. Cir. 2008), but ultimately remanded the rule
to EPA without vacatur to preserve the environmental benefits provided
by CAIR, North Carolina v. EPA, 550 F.3d 1176, 1178 (D.C. Cir. 2008).
On August 8, 2011 (76 FR 48208), acting on the D.C. Circuit's remand,
EPA promulgated the Cross-State Air Pollution Rule (CSAPR) to replace
CAIR and thus to address the interstate transport of emissions
contributing to nonattainment and interfering with maintenance of the
two air quality standards covered by CAIR as well as the 2006
PM2.5 NAAQS. CSAPR requires substantial reductions of
SO2 and NOX emissions from EGUs in 28 states in
the Eastern United States. As a general matter, because CSAPR is CAIR's
replacement, emissions reductions associated with CAIR will for most
areas be made permanent and enforceable through implementation of
CSAPR.
    Numerous parties filed petitions for review of CSAPR in the D.C.
Circuit, and on August 21, 2012, the court issued its ruling, vacating
and remanding CSAPR to EPA and ordering continued implementation of
CAIR. EME Homer City Generation, L.P. v. EPA, 696 F.3d 7, 38 (D.C. Cir.
2012). The D.C. Circuit's vacatur of CSAPR was reversed by the United
States Supreme Court on April 29, 2014, and the case was remanded to
the D.C. Circuit to resolve remaining issues in accordance with the
high court's ruling. EPA v. EME Homer City Generation, L.P., 134 S. Ct.
1584 (2014). On remand, the D.C. Circuit affirmed CSAPR in most
respects, but invalidated without vacating some of the CSAPR budgets as
to a number of states. EME Homer City Generation, L.P. v. EPA, 795 F.3d
118

(D.C. Cir. 2015) (EME Homer City II). The remanded budgets include the
Phase 2 SO2 emissions budgets for Georgia. The Phase 2
annual and ozone season NOX budgets for Georgia are not
affected by the Court's decision. The litigation over CSAPR ultimately
delayed implementation of that rule for three years, from January 1,
2012, when CSAPR's cap-and-trade programs were originally scheduled to
replace the CAIR cap-and-trade programs, to January 1, 2015. Thus, the
rule's Phase 2 budgets were originally promulgated to begin on January
1, 2014, and are now scheduled to begin on January 1, 2017. CSAPR will
continue to operate under the existing emissions budgets until EPA
addresses the D.C. Circuit's remand.
    Although the State identified CAIR as a permanent and enforceable
measure that contributed to attainment of the 1997 PM2.5
NAAQS in the Atlanta Area, EPA is proposing to approve the
redesignation of the Atlanta Area without relying the SO2
emissions reductions associated with CAIR at Georgia EGUs as having led
to attainment of the 1997 PM2.5 NAAQS or contributing to
maintenance of that standard.\9\ In so doing, we are proposing to
determine that the D.C. Circuit's invalidation of the Georgia CSAPR
Phase 2 SO2 emissions budgets does not bar today's proposed
redesignation. The Court's decision did not affect Georgia's CSAPR
Phase 2 annual NOX emissions budgets; therefore, CSAPR
ensures that the NOX emissions reductions associated with
CAIR at Georgia EGUs are permanent and enforceable.\10\
---------------------------------------------------------------------------

    \9\ The improvement in PM2.5 air quality in the Area
from nonattainment to attainment is not due to CSAPR emissions
reductions because, as noted above, CSAPR did not go into effect
until January 1, 2015, after the Area was already attaining the
standard.
    \10\ CAIR and CSAPR established annual NOX and
SO2 budgets to address nonattainment and interference
with maintenance of the PM2.5 standard because, as
discussed above in Section II, NOX and SO2 are
two primary PM2.5 precursors.
---------------------------------------------------------------------------

    In its redesignation request, Georgia noted that a number of states
significantly contributed to PM2.5 concentrations in the
Atlanta Area based on EPA air quality modeling. EPA identified the
Atlanta Area as an area that was significantly impacted by pollution
transported from other states in both CAIR and CSAPR, and these rules
greatly reduced the tons of SO2 emissions generated in the
states upwind of the Atlanta Area. The air quality modeling performed
for the CAIR rulemaking identified the following seven states as having
significantly contributed to PM2.5 concentrations in the
Atlanta Area: Alabama, Florida, Indiana, Kentucky, Ohio, South
Carolina, and Tennessee. See 70 FR 25162, 25247-49 (May 12, 2005). The
total annual SO2 emissions generated by EGUs in these seven
states in 2004, prior to the promulgation of CAIR in 2005, was
approximately 3,814,790 tons. Even though the first phase of CAIR
implementation for SO2 did not begin until 2010, many
sources began reducing their emissions well in advance of the first
compliance deadline because of the incentives offered by CAIR for early
compliance with the rule. Therefore, by 2008, the total annual
SO2 emissions generated by EGUs in the seven states
significantly contributing to nonattainment in the Atlanta Area was
approximately 2,636,952 tons, and by 2010, that volume had decreased to
approximately 1,814,572 tons.\11\ The vast majority of the
SO2 emission reductions in the states upwind of the Atlanta
Area achieved by CAIR, and made permanent by CSAPR, are unaffected by
the D.C. Circuit's remand of CSAPR.\12\
---------------------------------------------------------------------------

    \11\ This data was collected through the Acid Rain Program and
is available on EPA's CAMD Web site at http://www2.epa.gov/airmarkets.
    \12\ Only two of the seven state Phase 2 SO2 budgets
were remanded by the D.C. Circuit in EME Homer City II, and the
emissions from these two states represented only 19.5 percent
(515,165 tons) of the total SO2 EGU emissions from the
seven significantly contributing states in 2008, 19.3 percent
(375,913 tons) in 2009, and 16.5 percent (298,803 tons) in 2010. The
CSAPR Phase 2 SO2 budgets for the remaining five states,
and the emissions reductions those budgets require, are unaffected
by the Court's remand and are permanent and enforceable. Moreover,
updated air quality modeling performed for the CSAPR rulemaking
identified additional states that interfered with Atlanta's
attainment of the 1997 PM2.5 NAAQS, and SO2
emission reductions from those additional states are unaffected by
the D.C. Circuit's remand. 76 FR 48207, 48241 (August 8, 2011).
---------------------------------------------------------------------------

    Regarding the impact of SO2 emission reductions from
Georgia EGUs associated with CAIR, EPA is proposing to determine that
the Atlanta Area would have attained the 1997 PM2.5 NAAQS
even without those in-state EGU reductions. The Agency has reviewed an
analysis submitted by the State on January 10, 2015, and revised on
November 3, 2015, evaluating the sensitivity of PM2.5
concentrations in the Area to SO2 reductions associated with
Rule (sss).\13\ The analysis was based on photochemical modeling
conducted by the Visibility Improvement State and Tribal Association of
the Southeast (VISTAS). The State used this modeling to determine the
sensitivity of PM2.5 concentrations at the ten air quality
monitors in the Atlanta Area to reductions in SO2 emissions
from certain Georgia EGUs. The State then estimated, for each monitor,
the air quality impact of the SO2 emission reductions from
Georgia Rule (sss),\14\ and thus from CAIR, that occurred during the
relevant time period. Georgia estimated that the SO2
controls in place due to Rule (sss) by the end of 2009 reduced the
2008-2010 Annual PM2.5 design value by approximately 0.6
[micro]g/m\3\. Adding this impact to the highest 2008-2010 design value
for the Atlanta Area, 13.6 [micro]g/m\3\ for the Fire Station No. 8
site (with data substitution),\15\ yields a maximum PM2.5
concentration of 14.2 [micro]g/m\3\, meeting the 1997 Annual
PM2.5 standard of 15 [micro]g/m\3\. The State therefore
concluded that the Area would have attained the standard in the 2008-
2010 timeframe even without the SO2 emission reductions, in
place by the end of 2009, from Georgia Rule (sss).
---------------------------------------------------------------------------

    \13\ GA EPD, Sensitivity of Annual PM2.5 in Atlanta
to SO2 Emission Reductions Resulting from Georgia's
Multipollutant Rule [391-3-1-.02(2)(sss)] (attachment to a November
3, 2015, email from James Boylan, GA EPD, to Joel Huey, EPA Region
4, included in the docket for this action).
    \14\ By the end of 2009, Rule (sss) required FGD operation at
Plant Bowen Units 2 through 4, Plant Hammond Units 1 through 4,
Plant Wansley Units 1 and 2, and Plant Yates Unit 1.
    \15\ EPA's Clean Data Determination for the Atlanta Area
describes this data substitution. See 76 FR 76620 (December 8,
2011).
---------------------------------------------------------------------------

    EPA proposes to agree with this analysis and believes that adding
the 0.6 [micro]g/m\3\ value to the 2008-2010 design value is a
reasonable estimate of the actual impact of the SO2
emissions reductions due to Rule (sss) and CAIR at Georgia EGUs. For
more information about Georgia's sensitivity analysis and EPA's review
of that analysis, see the Rule (sss) impact TSD included in the docket
for this action.\16\
---------------------------------------------------------------------------

    \16\ EPA Region 4, Technical Support Document for Georgia Rule
(sss) Impact Analysis (November 2015).
---------------------------------------------------------------------------

    State Measures. The State identified Rules (sss) and (uuu) and the
State's April 16, 2008 smoke management plan as state control measures
that contributed to attainment of the 1997 PM2.5 NAAQS in
the Atlanta Area. Although Georgia describes these state measures in
the section of its submittal devoted to ``permanent and enforceable''
reductions under CAA section 107(d)(3)(E)(iii), ``enforceable'' means
federally enforceable. Therefore, state measures that are not approved
by EPA into a state's SIP are not ``enforceable'' for purposes of the
CAA. However, EPA does not believe that the state measures' lack of
enforceability poses a bar to proposed approval of the redesignation of
the Atlanta Area.
    First, as discussed above, EPA proposes to agree with the State's
sensitivity analysis demonstrating that the Area would have attained
the 1997

PM2.5 NAAQS even without the SO2 emission
reductions associated with the installation of SO2 controls
on Georgia EGUs subject to Rule (sss) and CAIR. To the extent that the
controls required by Rule (sss) also achieved annual NOX
reductions, CSAPR makes those reductions permanent and federally
enforceable with its federal implementation plan (FIP) regarding
Georgia's annual NOX emissions budget, which was not
affected by the D.C. Circuit's recent remand of other state
budgets.\17\ Second, to the extent that Rule (uuu) resulted in any
reductions before its January 1, 2010, compliance date, Georgia's
sensitivity analysis assumed that the FGD controls required by Rule
(sss) achieve the 95 percent reduction in SO2 emissions
required by Rule (uuu). Because Georgia's sensitivity analysis
demonstrates that Rule (sss) was not necessary for attainment of the
NAAQS in the Atlanta Area using emissions reductions associated with a
95 percent reduction in SO2, the same reduction required by
Rule (uuu), the analysis also demonstrates that Rule (uuu) was not
necessary for attainment prior to January 1, 2010. Finally, with regard
to the State's smoke management plan, that measure is focused on
protection of Georgia's forest land. While the SMP may result in some
direct PM emission reductions, such reductions are likely to be modest
because the SMP is not an emission reduction measure. The SMP was
developed as tool to minimize the public health and environmental
impacts of smoke intrusion into populated areas through better
management of fires that are important to forests and agricultural
resources. In addition, the State deemed it important to have an SMP in
place for the purpose of flagging unusually large forest fires as
exceptional events (which could impact an area's ability to show
maintenance through attaining design values). The rule therefore has
more impact on rural areas than an urban environment such as Atlanta,
where direct PM2.5 emissions from fires make up less than
one percent of the total direct PM2.5 emissions from fires
across the State.\18\ For these reasons, EPA has not relied on these
state-only rules as a basis for proposing approval of the redesignation
request and associated maintenance plan.
---------------------------------------------------------------------------

    \17\ 76 FR 48208, August 8, 2011.
    \18\ See 2011 emissions inventory information available at
http://www3.epa.gov/ttn/chief/eiinformation.html. Georgia also
stated that the measure is not necessary for the continued
maintenance of attainment in the Atlanta Area.
---------------------------------------------------------------------------

Criteria (4)--The Atlanta 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
Atlanta 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 for the reasons discussed below.
a. What is required in a maintenance plan?
    Section 175A of the CAA sets forth the elements of a maintenance
plan for areas seeking redesignation from nonattainment to attainment.
Under section 175A, the plan must demonstrate continued attainment of
the applicable NAAQS for at least 10 years after the Administrator
approves a redesignation to attainment. 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 proposes to find 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. Attainment Emissions Inventory
    As noted earlier, EPA has previously determined that the Atlanta
Area attained the 1997 Annual PM2.5 NAAQS based on
monitoring data for the 3-year period from 2008-2010. Today, EPA is
proposing to determine that the Atlanta Area has continued to attain
the 1997 Annual PM2.5 NAAQS up to the most recent 3-year
period quality-assured monitoring data, 2012-2014. In its maintenance
plan, the State selected 2008 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 Atlanta Area. As
noted above, the year 2008 was chosen as the base year for developing a
comprehensive emissions inventory for direct PM2.5 and
PM2.5 precursors SO2 and NOX. To
support maintenance through 2024, Georgia prepared emissions
projections for the years 2014, 2017, 2020, and 2024.
    The emissions inventories are composed of four major types of
sources: Point, area, on-road mobile, and non-road mobile. With the
exception of on-road emissions, Georgia obtained the 2008 base-year
emissions inventory from the National Emissions Inventory 2008 Version
1.5 (http://www3.epa.gov/ttnchie1/net/2008inventory.html). Georgia used
EPA's MOVES2010a mobile source emissions model to generate 2008 on-road
mobile source emissions. The 2008 actual SO2,
NOX, and PM2.5 emissions for the Atlanta Area, as
well as the emissions projections through 2024, were developed
consistent with EPA guidance and are summarized in Tables 3.1 and 4
through 7.1 of the following subsection discussing the maintenance
demonstration.
    Section 175A requires a state seeking redesignation to attainment
to submit a SIP revision to provide for the maintenance of the NAAQS in
the Area ``for at least 10 years after the redesignation.'' EPA has
interpreted this as a showing of maintenance ``for a period of ten
years following redesignation.'' Calcagni Memorandum, p. 9. Where the
emissions inventory method of showing maintenance is used, the purpose
is to show that emissions during the maintenance period will not
increase over the attainment year inventory. Calcagni Memorandum, pp.
9-10.
    As discussed in detail below, Georgia's maintenance plan submission
expressly documents that the Area's overall emissions inventories will
remain well below the attainment year inventories through 2024.
Although the State's maintenance demonstration includes projected
emissions reductions from Georgia Rules (sss) and (uuu), EPA believes
the plan still demonstrates maintenance as discussed in the following
subsection.

    In addition, for the reasons set forth below, EPA believes that the
Area will continue to maintain the 1997 Annual PM2.5 NAAQS
at least through 2025. Thus, if EPA finalizes its proposed approval of
the redesignation request and maintenance plans in 2015, the approval
will be based upon this showing, in accordance with section 175A, and
EPA's analysis described herein, that the State's maintenance plan
provides for maintenance for at least ten years after redesignation.
c. Maintenance Demonstration
    The August 30, 2012, submittal includes a maintenance demonstration
for the Atlanta Area through 2024. This demonstration uses 2008 as the
attainment year; identifies 2024 as the ``out year;'' and includes
future emission inventory projections for point, area, on-road mobile,
and non-road mobile sources in the Atlanta Area for 2014, 2017, 2020,
and 2024 (see Tables 3-7, below). The emissions projections for 2014
and 2020 provide reference points for periodic assessment of
maintenance of the NAAQS and were estimated using 2008 actuals and 2017
and 2024 projections. Appendix C of Georgia's 2012 submittal describes
the methodology used by the State to prepare the actual and projected
emissions inventories.
    The future emissions inventory projections in the State's
maintenance demonstration include reductions from the implementation of
Georgia Rules (sss) and (uuu). However, as discussed above, these two
State rules are not permanent and enforceable measures for the purposes
of redesignation. EPA therefore recalculated the projected 2014, 2017,
2020, and 2024 point source emissions in the Atlanta Area by removing
projected Rule (sss) and Rule (uuu) NOX, SO2, and
PM2.5 emissions reductions \19\ and replacing these
reductions with only those NOX, SO2, and
PM2.5 reductions from permanent and enforceable shutdowns at
Plant Branch Units 1 through 4 and Plant Yates Units 1 through 5 and
from permanent and enforceable conversions from coal to natural gas at
Plant Yates Units 6 and 7.\20\ Georgia did not incorporate the
emissions reductions resulting from these shutdowns and conversions in
its maintenance demonstration because they were not anticipated by the
State at the time of its 2012 submittal.
---------------------------------------------------------------------------

    \19\ Although, as discussed above, the NOX emission
reductions associated with Rule (sss) are permanent and enforceable
through CSAPR, EPA recalculated the projected point source emissions
without anticipated Rule (sss) NOX reductions to generate
a conservative maintenance demonstration.
    \20\ Georgia Power retired Plant Branch Unit 2 in September
2013; retired Plant Branch Units 1, 3, and 4 and Plant Yates Units
1-5 in April 2015; and converted Plant Yates Units 6 and 7 from coal
to natural gas in May 2015. Georgia Power certified under penalty of
law that the retirements are permanent in Retired Unit Exemption
(RUE) forms submitted to EPA under the Acid Rain, CAIR, and CSAPR
programs. The Plant Yates retirements and conversions occurred
through a Title V permit amendment effective on August 29, 2014.
Yates Steam-Electric Generating Plant Part 70 Operating Permit
Amendment No. 4911-077-0001-V-03-5. This Title V permit amendment
and the RUE forms discussed above are included in the docket.
---------------------------------------------------------------------------

    EPA removed the emissions reductions attributed to Georgia Rules
(sss) and (uuu) from the State's emissions projections by assuming that
NOX, SO2, and PM2.5 emissions from
EGUs in the Atlanta Area were not reduced through Rules (sss) and (uuu)
after 2008 and added the reductions from the aforementioned shutdowns
and conversions.\21\ Table 2.1 identifies the EGU emissions included in
the State's maintenance demonstration, and Table 2.2 identifies the EGU
emissions included in EPA's recalculated point source emission
projections for the Atlanta Area.
---------------------------------------------------------------------------

    \21\ EPA estimated the emissions reductions associated with
Rules (sss) and (uuu) and with the shutdowns and conversions to
natural gas using emissions projections provided by GA EPD on
November 13, 2015. These projections are included in the docket for
today's action.
    .

                   Table 2.1--EGU Emissions, Actual (2008) and Projected for the Atlanta Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2008            2014            2017            2020            2024
----------------------------------------------------------------------------------------------------------------
SO2.............................         410,496         169,176          48,516          49,781          50,413
NOX.............................          76,178          40,535          22,713          23,372          23,702
PM2.5...........................           4,938           3,760           3,171           3,296           3,358
----------------------------------------------------------------------------------------------------------------

     Table 2.2--EGU Emissions, Actual (2008) and Projected for the Atlanta Area, Revised To Include Only EGU
                                      Shutdowns and Natural Gas Conversions
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2008            2014            2017            2020            2024
----------------------------------------------------------------------------------------------------------------
SO2.............................         410,496         294,859         237,040         243,210         246,294
NOX.............................          76,177          58,173          49,171          50,519          51,193
PM2.5...........................           4,937           4,724           4,618           4,781           4,862
----------------------------------------------------------------------------------------------------------------

    Table 3.1 shows the 2008 actual point source emissions and the
projected future year point source emissions in the Atlanta Area
provided by the State in its 2012 submittal. Table 3.2 shows the 2008
actual point source emissions and projected future year point source
emissions using EPA's EGU projections shown in Table 2.2, above.

               Table 3.1--Point Source Emissions, Actual (2008) and Projected for the Atlanta Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2008            2014            2017            2020            2024
----------------------------------------------------------------------------------------------------------------
SO2.............................         413,478         172,170          51,697          52,601          53,803
NOX.............................          80,785          45,489          27,867          28,535          29,423

PM2.5...........................           5,637           4,541           3,993           4,120           4,288
----------------------------------------------------------------------------------------------------------------

Table 3.2--Point Source Emissions, Actual (2008) and Projected for the Atlanta Area, Revised To Include Only EGU
                                      Shutdowns and Natural Gas Conversions
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2008            2014            2017            2020            2024
----------------------------------------------------------------------------------------------------------------
SO2.............................         413,478         297,974         240,221         246,530         249,684
NOX.............................          80,785          63,145          54,325          56,051          56,914
PM2.5...........................           5,637           5,506           5,440           5,675           5,792
----------------------------------------------------------------------------------------------------------------

    Tables 4 through 6 show the actual and projected non-point, on-road
mobile, and non-road mobile source emissions for the Atlanta Area as
provided in the State's 2012 submittal. These emissions are not
impacted by Rules (sss) and (uuu) because these rules only apply to
certain EGUs.

              Table 4--Non-point Source Emission, Actual (2008) and Projected for the Atlanta Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2008            2014            2017            2020            2024
----------------------------------------------------------------------------------------------------------------
SO2.............................          10,237          10,557          10,717          10,884          11,107
NOX.............................          21,193          23,531          24,698          25,916          27,537
PM2.5...........................          35,686          40,052          42,232          44,072          46,520
----------------------------------------------------------------------------------------------------------------

           Table 5--On-Road Mobile Source Emissions, Actual (2008) and Projected for the Atlanta Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2008            2014            2017            2020            2024
----------------------------------------------------------------------------------------------------------------
SO2.............................             725             629             581             533             469
NOX.............................         128,955          93,806          76,258          58,675          35,272
PM2.5...........................           4,662           3,529           2,963           2,397           1,642
----------------------------------------------------------------------------------------------------------------

                  Table 6--Non-Road Emissions, Actual (2008) and Projected for the Atlanta Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2008            2014            2017            2020            2024
----------------------------------------------------------------------------------------------------------------
SO2.............................           1,675           1,516           1,437           1,553           1,708
NOX.............................          40,599          34,086          30,835          29,747          28,298
PM2.5...........................           2,827           2,360           2,127           1,967           1,755
----------------------------------------------------------------------------------------------------------------

    Below, Table 7.1 shows the 2008 actual emissions from all source
sectors and the projected future year emissions from all source sectors
in the Atlanta Area provided by the State. Table 7.2 reflects EPA's
revisions to the point-source emissions projections shown in Table 3.2,
above.

           Table 7.1--All Sector Emissions, Actual (2008) and Projected Emissions for the Atlanta Area
                                                     [Tons]
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2008            2014            2017            2020            2024
----------------------------------------------------------------------------------------------------------------
SO2.............................         426,115         184,873          64,433          65,572          67,088
NOX.............................         271,531         196,912         159,659         142,873         120,530
PM2.5...........................          48,811          50,482          51,316          52,556          54,205
----------------------------------------------------------------------------------------------------------------

 Table 7.2--All Sector Emissions, Actual (2008) and Projected Emissions for the Atlanta Area, Revised With EPA's
                                       Point-Source Emissions Projections
                                                    [Tons] 22
----------------------------------------------------------------------------------------------------------------
            Pollutant                  2008            2014            2017            2020            2024
----------------------------------------------------------------------------------------------------------------
SO2.............................         426,115         310,677         252,957         257,248         262,969
NOX.............................         271,531         214,589         186,117         173,715         157,179
PM2.5...........................          48,811          51,446          52,763          54,299          56,348
----------------------------------------------------------------------------------------------------------------

    The results of EPA's analysis, shown in Table 7.2, show that future
emissions for NOX and SO2 are expected to be well
below 2008 ``attainment level'' emissions without Georgia Rules (sss)
and (uuu), while direct PM2.5 emissions are expected to
increase slightly. In situations where local emissions are the primary
contributor to nonattainment, such as the Atlanta Area, if the future
projected emissions in the nonattainment area remain at or below the
baseline emissions in the nonattainment area, then the ambient air
quality standard should not be exceeded in the future. As explained
below, EPA proposes to find that the overall emission projections
illustrate that the Atlanta Area is expected to continue to attain the
1997 PM2.5 NAAQS through 2025. Moreover, as noted earlier,
the Atlanta Area was identified in EPA's federal interstate transport
rulemakings--CAIR and CSAPR--as an area that was projected to have
problems with nonattainment and maintenance of the 1997
PM2.5 NAAQS due to transported pollution from other states.
Continued implementation of CSAPR in the vast majority of those upwind
states will also help the Atlanta Area maintain the standard.
---------------------------------------------------------------------------

    \22\ The revised emission projections reflect no emission
reductions from EGUs beyond 2008 other than the permanent and
enforceable emission reductions that have occurred due to the
shutdowns and conversions identified above.
---------------------------------------------------------------------------

    As shown in Table 7.2, EPA projects that SO2 and
NOX emissions will decline by approximately 38 percent and
42 percent, respectively, from 2008 to 2024 without Georgia Rules (sss)
and (uuu). This decrease is due to the implementation of Federal
controls during the first half of the maintenance period and to the
permanent and enforceable shutdowns and conversions discussed above.
Emissions of PM2.5 are expected to increase by approximately
15.4 percent (7,537 tons) from 2008 through 2024 due to projected
increases in non-point source PM2.5 emissions. Therefore,
EPA further evaluated whether the increase in PM2.5
emissions, in combination with the decreases in SO2 and
NOX emissions, would provide for maintenance of 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 evaluate this relationship, the
State examined speciation data available from the EPA Air Explorer Web
site for 2007-2009 for the DeKalb County monitor (13-089-0002). The 3-
year average of this data suggests that ambient PM2.5 in
Atlanta consists of approximately 40.7 percent sulfate; 1.2 percent
nitrate; 50.1 percent organic particulate matter (which consists of
directly-emitted primary organic matter and atmospherically formed
secondary organic aerosol); 4.2 percent miscellaneous inorganic
particulate matter; and 3.7 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 approximately 54.3 percent of the
total ambient PM2.5.
    A conservative approach 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 component of ambient PM2.5 attributable to direct
PM2.5 species will increase by the same percentage as the
percentage increase in direct PM2.5 emissions projected for
the Atlanta Area (i.e., 15.4 percent). The baseline concentration is
conservatively assumed to be 15.0 [micro]g/m\3\, and direct
PM2.5 is estimated to contribute 54.3 percent, or 8.1
[micro]g/m\3\, of that baseline. Thus, a 15.4 percent increase in the
8.1 [micro]g/m\3\ of the direct PM2.5 component would
suggest a resulting 1.2 [micro]g/m\3\ increase in the ambient
concentration. As discussed earlier, the highest 2008-2010 design value
for the Atlanta Area was 13.6 [micro]g/m\3\ (with data substitution)
and the 2011-2014 design value is 11.1 [micro]g/m\3\ (with data
substitution). Thus, even if the design value were to increase by 1.2
[micro]g/m\3\, the standard of 15 [micro]g/m\3\ would still be met.
Furthermore, the projected increase in direct PM2.5
emissions (approximately 7,537 tons) will be at least partially, if not
fully, offset by a significant decrease in sulfate and nitrate
emissions, resulting in a continued decrease in the PM2.5
design values in the Atlanta Area. As shown in Table 7.2, EPA expects
that, at a minimum, SO2 and NOX emissions will
decrease by approximately 163,146 tons and 114,352 tons, respectively,
from 2008 through 2024.
    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
believes that the projected emissions demonstrate that the Atlanta Area
will continue to attain for the duration of the maintenance plan.
    While GA EPD's maintenance plan projects maintenance of the 1997
Annual PM2.5 NAAQS through 2024, as noted above, EPA
believes that the Atlanta Area will continue to maintain the standard
at least through the year 2025 for several reasons: All of the federal
regulatory requirements that enabled the Area to attain the NAAQS will
continue to be in effect and enforceable after the 10-year maintenance
period; the most recent maximum potential annual PM2.5
design value (for the period 2012 to 2014) for the Area, 11.1 [micro]g/
m\3\,\23\ is well below the standard of 15.0 [micro]g/m\3\; and overall
emissions are projected to decline significantly through 2024. Because
it is highly improbable that emissions will suddenly increase after
2024 and exceed attainment year inventory levels in 2025, EPA expects
the projected downward trend in pollutant emissions in the Atlanta Area
to continue to demonstrate maintenance of the 1997 PM2.5
NAAQS through at least the year 2025.
---------------------------------------------------------------------------

    \23\ As noted earlier, due to incomplete data at one monitoring
site during the third quarter of 2012, EPA conducted a statistical
analysis to determine a maximum potential design value of 11.1
[micro]g/m\3\ for the period 2012 to 2014. The analysis is described
in detail in the monitoring TSD included in the docket for this
rulemaking.

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

d. Monitoring Network
    There are currently seven monitors measuring ambient
PM2.5 in the Atlanta Area. GA EPD has committed to continue
operation of the monitors in the Atlanta Area in compliance with 40 CFR
part 58 and have thus addressed the requirement for monitoring. EPA
approved Georgia's 2014 monitoring plan on November 7, 2014.
e. Verification of Continued Attainment
    The State of Georgia, through the GA EPD, has the legal authority
to enforce and implement the requirements of the Atlanta 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
Atlanta 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 Atlanta
Area.
f. Contingency Measures in the Maintenance Plan
    Section 175A of the CAA requires that a maintenance plan include
such contingency measures as EPA deems necessary to assure that the
state will promptly correct a violation of the NAAQS that occurs after
redesignation. The maintenance plan should identify the contingency
measures to be adopted, a schedule and procedure for adoption and
implementation, and a time limit for action by the State. A state
should also identify specific indicators to be used to determine when
the contingency measures need to be implemented. The maintenance plan
must include a requirement that a state will implement all measures
with respect to control of the pollutant that were contained in the SIP
before redesignation of the area to attainment in accordance with
section 175A(d).
    The contingency measures included in Georgia's maintenance plan for
the Atlanta Area include 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's
trigger mechanisms include two tiers: Tier I and Tier II.
    A Tier I trigger is activated when any of the following conditions
occurs:
     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 10.0 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.
    A Tier II trigger is activated when any violation of the 1997
Annual PM2.5 NAAQS at any federal reference method (FRM)
monitor in the Atlanta maintenance area is recorded, based on quality-
assured monitoring data.
    In the event of either a Tier I or Tier II trigger, GA EPD will
conduct a comprehensive study as expeditiously as practicable, but no
later than nine months after the trigger is activated. GA EPD will
evaluate a Tier I condition, if it occurs, 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. GA EPD will
evaluate a Tier I condition, if it occurs, to determine the cause of
the trigger and determine if the cause(s) of the ambient
PM2.5 increase and to determine if the increase is likely to
continue. Through the comprehensive study, GA EPD will attempt to
determine whether the trigger condition is due to local emissions,
emissions from elsewhere, or a combination of these. The study will
also include a determination regarding the emissions control measures
that may be necessary to prevent or correct a violation of the NAAQS.
    GA EPD 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. Previously
adopted controls, which have not yet realized emission reductions and
which are not relied upon in the maintenance demonstration, will be
implemented within 24 months from trigger activation.\24\ If the study
determines that such previously adopted emission control programs are
not sufficient to address any violation of the NAAQS, EPD will adopt
additional rules or controls to require further emission reductions.
Any additional rules or controls to address a violation would be
adopted and implemented within 24 months of trigger activation and will
be submitted to EPA for approval into Georgia's SIP.
---------------------------------------------------------------------------

    \24\ In a September 23, 2013, letter to EPA, the State clarified
the timing and content of its contingency measures included in the
maintenance plan for the Atlanta Area. In this letter, the State
reaffirmed its commitment to address and correct any violation of
the 1997 annual PM2.5 NAAQS as expeditiously as
practicable and to do so no later than 24 months from the trigger
activation.
---------------------------------------------------------------------------

    In any event, if a Tier II trigger is activated, EPD will consult
and seek review from EPA on the analysis to determine the cause of the
violation. The contingency measure(s) will be selected from the
following types of emission controls or from any other control deemed
appropriate and effective at the time the selection is made by EPD:
     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 August
30, 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 preliminarily 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 Atlanta 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 II of this notice, 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.
    For the purposes of evaluating Georgia's redesignation request for
the Atlanta 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 Atlanta 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'').\25\ In this case, at the time that Georgia submitted its
redesignation request on August 30, 2012, requirements under subpart 4
were not due, and indeed, were not yet known to apply.
---------------------------------------------------------------------------

    \25\ 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.
---------------------------------------------------------------------------

    On June 2, 2014, EPA published a rule entitled ``Identification of
Nonattainment Classification and Deadlines for Submission of State
Implementation Plan (SIP) Provisions for the 1997 Fine Particle
(PM2.5) National Ambient Air Quality Standard (NAAQS) and
2006 PM2.5 NAAQS'' (``Classification and Deadlines Rule'').
79 FR 31,566.\26\ In that rule, the Agency responded to the DC
Circuit's January 2013 decision by establishing classifications for
PM2.5 nonattainment areas under subpart 4, and by
establishing a new SIP submission date of December 31, 2014, for
moderate area attainment plans and for any additional attainment-
related or nonattainment new source review plans necessary for areas to
comply with the requirements applicable under subpart 4. Id. at 31,567-
70. Therefore, when Georgia submitted its request in August 2012, the
deadline for submitting a SIP to meet the Act's subpart 4 requirements
had not yet passed, and those requirements are therefore not applicable
for purposes of evaluating Georgia's request for redesignation.
---------------------------------------------------------------------------

    \26\ Judicial review of EPA's Classification and Deadlines Rule
is pending in the D.C. Circuit. At the time of this notice, briefing
and oral arguments in that case have concluded but a decision has
not yet been issued by the Court. See WildEarth Guardians v. EPA,
No. 14-1145 (D.C. Circuit, argued November 6, 2015).
---------------------------------------------------------------------------

b. Subpart 4 Requirements and the Atlanta Area Redesignation Request

    Even though the substantive requirements of subpart 4 were not
applicable requirements that Georgia was required to have met at the
time of its redesignation request submission, EPA believes that even
the imposition of those substantive requirements would not pose a bar
to the redesignation of the Atlanta Area. The additional requirements
found in subpart 4 are either designed to help an area achieve
attainment (also known as ``attainment planning requirements'') or are
related to new source permitting. None of these additional requirements
are applicable for purposes of evaluating a redesignation from
nonattainment to attainment under EPA's long-standing interpretation of
CAA section 107(d)(3)(E)(ii) and (v).
    As background, 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 \27\ 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.\28\
In the General Preamble, EPA's longstanding general guidance
interpreting the 1990 amendments to the CAA,\29\ EPA discussed the
relationship of subpart 1 and subpart 4 SIP requirements and pointed
out that subpart 1 requirements were to an extent ``subsumed by, or
integrally related to, the more specific PM-10 requirements.'' See 57
FR 13538 (April 16, 1992). The subpart 1 requirements include, among
other things, provisions for attainment demonstrations, RACM, RFP,
emissions inventories, and contingency measures.
---------------------------------------------------------------------------

    \27\ PM10 refers to particles nominally 10
micrometers in diameter or smaller.
    \28\ In explaining their decision, the court reasoned that the
plain meaning of the CAA requires implementation of the 1997 p.m.2.5
NAAQS under subpart 4 because PM2.5 particles fall within
the statutory definition of PM10 and are thus subject to
the same statutory requirements. The EPA has proposed its
interpretation of subpart 4 requirements as applied to the
PM2.5 NAAQS in its proposal rule entitled ``Fine
Particulate Matter National Ambient Air Quality Standards: State
Implementation Plan Requirements'' (80 FR 15340, March 23, 2015).
    \29\
---------------------------------------------------------------------------

    As noted above, in the Classification and Deadlines Rule, EPA
initially classified all areas designated nonattainment for either the
1997 or the 2006 PM2.5 NAAQS as ``moderate'' nonattainment
areas. Additional requirements that would apply to the Atlanta Area as
a moderate nonattainment area are therefore Sections 189(a) and (c),
including 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)).\30\
---------------------------------------------------------------------------

    \30\ EPA's proposed implementation rule (80 FR 15340 (March 23,
2015)) includes, among other things, the Agency's proposed
interpretation of these moderate area requirements for purposes of
PM2.5 NAAQS implementation.
---------------------------------------------------------------------------

    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.\31\ 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).
---------------------------------------------------------------------------

    \31\ 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,\32\ EPA applies the same interpretation that it applies to
attainment planning requirements under subpart 1 or any of other
pollutant-specific subparts. That is, under its long-standing
interpretation of the CAA, where an area is already attaining the
standard, EPA does not consider those attainment-planning requirements
to be applicable for purposes of evaluating a request for redesignation
because requirements that are designed to help an area achieve
attainment no longer have meaning where an area is already meeting the
standard.
---------------------------------------------------------------------------

    \32\ These planning requirements include the attainment
demonstration, quantitative milestone requirements, and RACM
analysis.
---------------------------------------------------------------------------

    Thus, at the time of Georgia's submission of its redesignation
request, the requirement for the Atlanta Area to comply with subpart 4
had not yet come due and was, therefore, not applicable for purposes of
EPA's evaluation of the redesignation. Moreover, even if Georgia had
been required to comply with those subpart 4 requirements, the
additional substantive requirements for a moderate nonattainment area
under subpart 4 were not applicable for purposes of redesignation
anyway, given EPA's long-standing interpretation of the applicability
of certain requirements to areas that are attaining the NAAQS.

c. Subpart 4 and Control of PM2.5 Precursors

    As noted previously, EPA does not believe that the requirement to
comply with subpart 4 applied to the Atlanta Area redesignation request
because that request was submitted prior to the moderate area SIP
submission date of December 31, 2014. However, even if the requirements
of subpart 4 were to apply to the Atlanta Area, EPA nevertheless
believes that the additional requirements of subpart 4 would not pose
an obstacle to our approval of Georgia's request to redesignate the
Atlanta Area. Specifically, EPA proposes to determine that, because the
Atlanta Area is attaining the standard, no additional controls of any
PM2.5 precursors would be required. 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. Relevant precursors to PM2.5 pollution
include SO2, NOx, VOC and ammonia. Moreover, CAA section
189(e) in subpart 4 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.''
    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, assuming
subpart 4 requirements are applicable for purposes of evaluating this
redesignation request, EPA is analyzing 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, EPA does not
believe that any additional controls of ammonia and VOC are required in
the context of this redesignation.
    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 Atlanta Area contains only one major stationary source of
ammonia (Owens Corning, Fairburn Plant), and (2) existing major
stationary sources of VOC are adequately controlled under other
provisions of the CAA regulating the ozone NAAQS.\33\ 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 Atlanta Area. See
57 FR 13539.
---------------------------------------------------------------------------

    \33\ The Atlanta Area has reduced VOC emissions through the
implementation of various control programs including various on-road
and non-road motor vehicle control programs.
---------------------------------------------------------------------------

    As noted earlier, EPA determined in December 2011 that the Atlanta
Area was attaining the 1997 Annual PM2.5 NAAQS and that the
Area had attained the NAAQS by the applicable attainment date of April
5, 2010. 76 FR 76620. Under EPA's regulations, a determination of
attainment, also known as a clean data determination, suspends the
CAA's requirements to submit an attainment demonstration, including an
analysis of reasonably available control measures and control
technology; reasonable further progress; and contingency measures.
Under subpart 4, Georgia's plan for attaining the 1997 PM2.5
NAAQS in the Atlanta Area would have had to consider all
PM2.5 precursors, including VOC and ammonia, and whether
there were control measures, including for existing sources under
section 189(e), available that would have advanced the area's
attainment goals. However, because the Atlanta Area has already
attained the 1997 PM2.5 NAAQS, the state's requirement to
submit a plan demonstrating how the area would attain has been
suspended, and, moreover, the area has shown that it has attained with
its current approach to regulation of PM2.5 precursors.
Therefore, 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. In addition, as noted below, EPA has analyzed
projections of VOC and ammonia emissions in the area and has determined
that VOC emissions are projected to decrease sharply over the
maintenance period and ammonia emissions, which are emitted in marginal
amounts in the Atlanta area, are projected to increase only slightly.
Accordingly, EPA does not view the January 4, 2013, decision of the
Court as precluding redesignation of the Atlanta Area to attainment for
the 1997 Annual PM2.5 NAAQS. In sum, even if Georgia were
required to address precursors for the Atlanta 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).

d. Maintenance Plan and Evaluation of Precursors

    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 Atlanta 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 Atlanta
Area need not include any additional emission reductions of VOC or
ammonia in order to provide for continued maintenance of the standard.
    First, as noted above in EPA's discussion of section 189(e), VOC
emission levels in this area have historically been well-controlled
under SIP requirements related to ozone and other pollutants. Second,
total ammonia emissions throughout the Atlanta Area are projected to be
approximately 13,620 tons per year in 2020. See Table 8 below. This
amount of ammonia emissions is relatively low in comparison to the
total amounts of SO2, NOX, and even direct
PM2.5 emissions from sources in the Area. Third, 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.
    The emissions inventories used in the regulatory impact analysis
(RIA) for the 2012 PM2.5 NAAQS, included in the docket for
today's action, show that VOC emissions are projected to decrease by
52,813.38 tpy and that ammonia emissions are projected to increase by
91.89 tpy in the Area between 2007 and 2020. See Table 8, below. Thus,
emissions of VOC are projected to decrease by 30 percent, and emissions
of ammonia are projected to remain about the same, increasing by less
than one percent.
---------------------------------------------------------------------------

    \34\ These emissions estimates were taken from the emissions
inventories developed for the regulatory impact analysis for the
2012 PM2.5 NAAQS.

                       Table 8--Comparison of 2007 and 2020 VOC and Ammonia Emission Totals by Source Sector (tpy) for the Area 34
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                VOC                                           Ammonia
                      Source sector                      -----------------------------------------------------------------------------------------------
                                                               2007            2020         Net Change         2007            2020         Net Change
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nonpoint................................................       76,274.51       74,736.27       -1,538.24       10,220.59       11,535.64        1,315.05
Non-road................................................       28,433.41       16,376.46      -12,056.95           31.17           38.96            7.79
Onroad..................................................       64,157.97       25,202.79      -38,955.18        2,587.41        1,570.67       -1,016.74
Point...................................................        6,639.28        6,376.27         -263.01          689.03          474.82         -214.21
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................      175,505.17      122,691.79      -52,813.38       13,528.20       13,620.09           91.89
--------------------------------------------------------------------------------------------------------------------------------------------------------

    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 Atlanta 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 is consistent with continued attainment.
    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 Atlanta Area recorded a maximum
potential annual PM2.5 design value of 11.1 [mu]g/m\3\
during 2012-2014, the most recent three years available with 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. In the RIA analysis, the
2020 modeled design value for the Atlanta Area is 9.4 [micro]g/m\3\.
Given the decrease in overall precursor emissions projected through
2024, and expected through 2025, it is reasonable to conclude that the
monitored PM2.5 concentration in this area will also
continue to decrease through 2025.
    Thus, EPA believes that there is ample justification to conclude
that the Atlanta Area should be redesignated, even taking into
consideration the emissions of VOC and ammonia potentially relevant to
PM2.5. After consideration of the DC 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 Atlanta 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 Atlanta 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. A MVEB is the portion of the total allowable emissions in the
maintenance demonstration that is allocated to highway and transit
vehicle use and emissions. See 40 CFR 93.101. The MVEBs serve 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 Atlanta Area, Georgia has elected to develop MVEBs for
NOX and PM2.5 for the entire Area. Georgia has
developed these MVEBs, as required, for the last year of its
maintenance plan, 2024. The NOX and PM2.5 MVEBs
were developed in consultation with the transportation partners and
were added to account for uncertainties in population growth, changes
in model vehicle miles traveled and new emission factor models. Further
details are provided below to explain how the MVEBs for 2024 were
derived.
    The State estimated the worst case daily motor vehicle projections
for NOX and PM2.5 in 2024 and set the MVEBs at
this level. The worst-case daily motor vehicle emissions projection for
PM2.5 is 2,281 tons (38.9 percent above the projected 2024
on-road emissions), and the worst-case daily motor vehicle emissions
projection for NOX is 44,430 tons (26 percent above the
projected 2024 on-road emissions). The proposed
NOX and PM2.5 MVEBs for the Atlanta
Area are identified in Table 9, below. On-road emissions of
SO2 are considered de minimis; therefore, no budget for
SO2 is required. See 70 FR 24280, 24283 (May 6, 2005).

           Table 9--Proposed Atlanta Area NOX and PM2.5 MVEBs
                                  [tpy]
------------------------------------------------------------------------
                                                          NOX     PM2.5
------------------------------------------------------------------------
2024 On-Road Mobile Emissions.........................   35,272    1,642
2024 Safety Margin Allocated..........................    9,158  .......
2024 Total Motor Vehicle Budget.......................   44,430    2,281
------------------------------------------------------------------------

    The 9,158 ton difference in the NOX projections is well
within the NOX ``safety margin.'' \35\ 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.
---------------------------------------------------------------------------

    \35\ The difference between the 2024 NOX emissions
projected by EPA and 2008 actual NOX emissions (i.e.,
NOX safety margin) is approximately 114,352 tons.
---------------------------------------------------------------------------

    Although there is no apparent safety margin for PM2.5
because overall emissions of direct PM2.5 from all source
categories are projected to increase by approximately 15 percent from
2008 to 2024 (see Table 7.2), the on-road mobile NOX and
PM2.5 emissions are projected to decrease by approximately
72 percent and 65 percent, respectively (see Table 5) due to the
federal mobile source measures discussed in Section V. Table 10, below,
shows that the percentage of the PM2.5 on-road mobile source
emissions as compared to the overall PM2.5 emissions from
all sectors trends downward from 9.6 percent in 2008 to 3.0 percent in
2024.

  Table 10--PM2.5 On-Road Mobile Sources Emissions Comparison to the Total PM2.5 Emissions From All Sectors for
                                                the Atlanta Area
                                                 [Tons per year]
----------------------------------------------------------------------------------------------------------------
                                       2008            2014            2017            2020            2024
----------------------------------------------------------------------------------------------------------------
PM2.5 emissions--on-road mobile.           4,662           3,529           2,963           2,397           1,642
Total PM2.5 emissions--all                48,811          51,256          52,478          54,285          55,188
 sectors........................
On-road mobile % of total PM2.5              9.6             6.9             5.7             4.4             3.0
 emissions......................
----------------------------------------------------------------------------------------------------------------

    As discussed in Section V, EPA believes that Area will maintain the
NAAQS through 2025 and that the impact of the projected increase in
PM2.5 emissions will be overcompensated by the projected
decreases in the emissions of SO2 and NOX.
Furthermore, even if mobile source emissions are equal to the worst-