[Federal Register Volume 78, Number 165 (Monday, August 26, 2013)]
[Proposed Rules]
[Pages 52733-52753]
[FR Doc No: 2013-20651]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R05-OAR-2011-0597; FRL-9900-29-Region 5]

Approval and Promulgation of Air Quality Implementation Plans;
Ohio; Redesignation of the Columbus Area to Attainment of the 1997
Annual Standard for Fine Particulate Matter

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to grant, under the Clean Air Act (CAA), a
redesignation request and approve a State Implementation Plan (SIP)
revision request submitted by the state of Ohio on June 3, 2011, and
supplemented on April 30, 2013. The Ohio Environmental Protection
Agency (OEPA) has requested the redesignation of the Columbus, Ohio
(OH) area to attainment of the 1997 annual fine particulate
(PM2.5) National Ambient Air Quality Standard (NAAQS or
standard). The Columbus, Ohio area (Columbus area) includes Coshocton,
Delaware, Licking, Fairfield, and Franklin Counties. EPA is proposing
to determine that the Columbus area has attained the 1997 annual
PM2.5 NAAQS and to approve the state's redesignation
request. EPA is proposing to approve related Ohio SIP revisions,
including the state's plan for maintaining attainment of the 1997
annual PM2.5 NAAQS in the Columbus area through 2023, the
state's 2022 Nitrogen Oxides (NOX) and PM2.5
Motor Vehicle Emission Budgets (MVEBs) for the Columbus area (which EPA
is also proposing to find adequate), and 2005 NOX, Sulfur
Dioxide (SO2), and primary PM2.5 and 2007
Volatile Organic Compound (VOC) and ammonia emission inventories for
the Columbus area. In the context of this proposal to redesignate the
Columbus area, EPA addresses a number of additional issues, including
the effects of two decisions of the United States Court of Appeals for
the District of Columbia (D.C. Circuit or Court): The Court's August
21, 2012, decision to vacate and remand to EPA the Cross-State Air
Pollution Rule (CSAPR); and the Court's January 4, 2013, decision to
remand to EPA two final rules implementing the 1997 annual
PM2.5 standard.

DATES: Comments must be received on or before September 25, 2013.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2011-0597, by one of the following methods:
     http://www.regulations.gov: Follow the on-line
instructions for submitting comments.
     Email<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER>.
     Mail: Douglas Aburano, Chief, Attainment Planning and
Maintenance Section (AR-18J), U.S. Environmental Protection Agency, 77
West Jackson Boulevard, Chicago, Illinois 60604.
     Hand Delivery: Douglas Aburano, Attainment Planning and
Maintenance Section, Air Programs Branch (AR-18J), U.S. Environmental
Protection Agency, 77 West Jackson Boulevard, 18th Floor, Chicago,
Illinois 60604. Such deliveries are only accepted during the Regional
Office's normal hours of operation, and special arrangements should be
made for deliveries of boxed information. The Regional Office 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-R05-OAR-
2011-0597. EPA's policy is that all comments

received will be included in the public docket without change and may
be made available online at www.regulations.gov, including any personal
information provided, unless the comment includes information claimed
to be Confidential Business Information (CBI) or other information
whose disclosure is restricted by statute. Do not submit information
that you consider to be CBI or otherwise protected through
www.regulations.gov or email. 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 and viruses. For additional instructions on submitting
comments, go to section I of the SUPPLEMENTARY INFORMATION section of
this document.
    Docket: All documents in the docket are listed in the
www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in www.regulations.gov or in hard copy at the U.S. Environmental
Protection Agency, Region 5, Air and Radiation Division, 77 West
Jackson Boulevard, Chicago, Illinois 60604. This facility is open from
8:30 a.m. to 4:30 p.m., Monday through Friday, excluding Federal
holidays. We recommend that you telephone Edward Doty at<PHONE_NUMBER>
before visiting the Region 5 office.

FOR FURTHER INFORMATION CONTACT: Edward Doty, Environmental Scientist,
Attainment Planning and Maintenance Section, Air Programs Branch (AR-
18J), Environmental Protection Agency, Region 5, 77 West Jackson
Boulevard, Chicago, Illinois 60604,<PHONE_NUMBER>, or
<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,''
``us,'' or ``our'' is used, we mean EPA. This SUPPLEMENTARY INFORMATION
section is arranged as follows:

I. What should I consider as I prepare my comments for EPA?
II. What actions is EPA proposing?
III. What is the background for these actions?
IV. What are the criteria for redesignation to attainment?
V. What is EPA's analysis of the State's request?
    A. Has the Columbus area attained the 1997 annual
PM2.5 standard?
    B. Has the State of Ohio met all plan requirements of the CAA
applicable for purposes of redesignation of the Columbus area to
attainment of the 1997 annual PM2.5 standard?
    1. Ohio Has Met All Applicable Requirements for Purposes of
Redesignation of the Columbus Area Under Section 110 and Part D of
the CAA
    a. Section 110 General SIP Requirements
    b. Part D Requirements
    2. The Columbus Area Has a Fully Approved Applicable SIP Under
Section 110(k) of the CAA
    3. Nonattainment Requirements
    4. Effect of the January 4, 2013, D.C. Circuit Decision
Regarding PM2.5 Implementation Under Subpart 4 of the CAA
    a. Background
    b. Proposal on This Issue
    i. Applicable Requirements for Purposes of Evaluating the
Redesignation Request
    ii. Subpart 4 Requirements and Ohio's Redesignation Request
    iii. Subpart 4 and Control of PM2.5 Precursors
    C. Are the PM2.5 air quality improvements in the
Columbus area due to permanent and enforceable emission reductions?
    1. Permanent and Enforceable Emission Controls
    a. Federal Emission Control Measures
    i. Tier 2 Emission Standards for Vehicles and Gasoline Sulfur
Standards
    ii. Heavy-Duty Diesel Engine Rule
    iii. Non-Road Diesel Engine Standards
    iv. Non-Road Spark-Ignition Engines and Recreational Engine
Standards
    b. Control Measures in Upwind Areas
    i. NOX SIP Call
    ii. Clean Air Interstate Rule (CAIR) and CSAPR
    2. Emission Reductions
    a. Ohio's Demonstration That Significant Emission Reductions
Have Occurred in the Columbus Area and in Upwind Areas
    b. VOC and Ammonia Emission Reductions
    c. Conclusions Regarding Emission Reductions Between 2005 and
2008 in the Columbus Area
    D. Does Ohio have a fully approvable PM2.5
maintenance plan pursuant to section 175A of the CAA for the
Columbus area?
    1. What is required in a maintenance plan?
    2. Attainment Inventory
    3. Demonstration of Maintenance
    a. State Demonstration of Maintenance
    b. CAIR and CSAPR
    i. Background--Effect of the August 21, 2012, D.C. Circuit
Decision garding EPA's CSAPR
    ii. Maintenance Plan Precursor Evaluation Resulting From Court
Decisions
    c. EPA's Conclusion for Ohio's Maintenance Demonstration
    4. Monitoring Network
    5. Verification of Continued Attainment
    6. Contingency Plan
    7. Provision for Future Update of the Annual PM2.5
Maintenance Plan
    E. Has Ohio adopted acceptable MVEBs for the PM2.5
maintenance period?
    1. How are MVEBs developed and what are the MVEBs for the
Columbus area?
    2. What are safety margins?
    F. Are the 2005 and 2007 base year PM2.5-related
emissions inventories for the Columbus area approvable under section
172(c)(3) of the CAA?
    1. EPA's Base Year Emissions Inventory SIP Policy
    2. 2005 and 2007 Base Year PM2.5-Related Emission
Inventories for the Columbus Area
VI. Statutory and Executive Order Reviews

I. What should I consider as I prepare my comments for EPA?

    When submitting comments, remember to:
    1. Identify the rulemaking by docket number and other identifying
information (subject heading, Federal Register date and page number).
    2. Follow directions--EPA may ask you to respond to specific
questions or to organize comments by referencing a Code of Federal
Regulations (CFR) part or section number.
    3. Explain why you agree or disagree; suggest alternatives and
substitute language for your requested changes.
    4. Describe any assumptions and provide any technical information
and/or data you used.
    5. If you estimate potential costs or burdens, explain how you
arrived at your estimate in sufficient detail to allow for it to be
reproduced.
    6. Provide specific examples to illustrate your concerns, and
suggest alternatives.
    7. Explain your views as clearly as possible, avoiding the use of
profanity or personal threats.
    8. Make sure to submit your comments by the comment period deadline
identified in the proposed rule.

II. What actions is EPA proposing?

    EPA is proposing to take several actions related to the
redesignation of the Columbus area to attainment of the 1997 annual
PM2.5 NAAQS. EPA is proposing to determine that the Columbus
area has attained the 1997 annual PM2.5 NAAQS based on
quality

assured, certified 2008-2012 air quality data.
    EPA is proposing to find that the state of Ohio and the Columbus
area meet requirements for redesignation of the Columbus area to
attainment of the 1997 annual PM2.5 NAAQS under section
107(d)(3)(E) of the CAA. EPA is, thus, proposing to grant Ohio's
request for a redesignation of the Columbus area to attainment of the
1997 annual PM2.5 NAAQS.
    EPA is proposing to approve Ohio's PM2.5 maintenance
plan for the 1997 annual PM2.5 NAAQS for the Columbus area
as a revision to the Ohio SIP, meeting the requirements of section 175A
of the CAA. The PM2.5 maintenance plan uses projected
emissions data for 2022, but EPA believes that the plan suffices to
demonstrate maintenance of the 1997 annual PM2.5 NAAQS in
the Columbus area through 2023. The state of Ohio commits to revise
this maintenance plan to cover an additional 10 years within 8 years
after EPA approves the redesignation of the Columbus area to attainment
of the 1997 annual PM2.5 NAAQS.
    EPA is proposing to approve Ohio's 2022 PM2.5 and
NOX MVEBs for the Columbus area. In addition, EPA is
proposing to find these MVEBs as adequate for purposes of
transportation and general conformity demonstrations and
determinations.
    Finally, EPA is proposing to approve 2005 primary PM2.5,
NOX, and SO2 emission inventories and 2007 VOC
and ammonia emission inventories for the Columbus area as satisfying
the requirement of section 172(2)(3) of the CAA for a current,
accurate, and comprehensive emission inventory.

III. What is the background for these actions?

    Fine particulate pollution can be emitted directly from a source
(e.g., primary PM2.5, organic particles, crustal matter, and
elemental carbon) or formed secondarily through chemical reactions in
the atmosphere involving precursor pollutants emitted from a variety of
sources. Sulfates are a type of secondary fine particulates formed from
reactions involving SO2 emissions from power plants and
industrial facilities. Nitrates, another common type of secondary
particulate, are formed from combustion emissions of NOX
(primarily NO and NO2) from power plants, mobile sources,
and other combustion sources. Emitted precursors of general concern in
the secondary formation of PM2.5 are SO2,
NOX, VOC, ammonia, and primary PM2.5, all of
which can react in the atmosphere with other compounds to form fine
particulates locally (within or immediately downwind of significant
source areas) and adding to PM2.5 levels produced through
local primary PM2.5 emissions and transported
PM2.5 and PM2.5 precursors.
    The first air quality standards for PM2.5 were
promulgated on July 18, 1997, at 62 FR 38652. EPA promulgated an annual
standard at a level of 15 micrograms per cubic meter ([mu]g/m\3\) of
ambient air, based on a three-year average of the annual mean
PM2.5 concentrations at each monitoring site (the site's
PM2.5 design value for the annual standard). In the same
rulemaking, EPA promulgated a 24-hour PM2.5 standard at a
level of 65 [mu]g/m\3\, based on a three-year average of the annual
98th percentile of 24-hour PM2.5 concentrations at each
monitoring site.
    On January 5, 2005, at 70 FR 944, EPA published air quality area
designations for the 1997 annual PM2.5 standard based on air
quality data for calendar years 2001-2003. In that rulemaking, EPA
designated the Columbus area as nonattainment for the 1997 annual
PM2.5 standard.
    On October 17, 2006, at 71 FR 61144, the EPA retained the annual
PM2.5 standard at 15 [mu]g/m\3\ (2006 annual
PM2.5 standard), but revised the 24-hour PM2.5
standard to 35 [mu]g/m\3\, based again on the three-year average of the
annual 98th percentile of the 24-hour PM2.5 concentrations.
In response to legal challenges of the 2006 annual PM2.5
standard, the U.S. Court of Appeals for the District of Columbia
Circuit (D.C. Circuit) remanded this standard 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).
    On January 15, 2013 (78 FR 3086), EPA finalized a rule revising the
annual PM2.5 standard to 12 [mu]g/m\3\ based on current
scientific evidence regarding the protection of public health. EPA has
not established attainment and nonattainment areas for this revised
annual standard and is not addressing this standard in this proposal.
    Since the Columbus area is designated as nonattainment for the 1997
annual PM2.5 standard and not for other PM2.5
standards, today's proposed action addresses redesignation of this area
for only this standard.
    On September 14, 2011, EPA issued a final determination that the
Columbus area had attained the 1997 annual PM2.5 standard by
the applicable attainment date (76 FR 56641). This determination of
attainment for the 1997 annual PM2.5 standard was based on
quality-assured annual-averaged PM2.5 concentrations for
PM2.5 monitoring sites in Franklin County for the periods of
2007-2009 and 2008-2010. Based on our review of complete, quality-
assured, and state-certified ambient PM2.5 monitoring data
from 2010-2012, we are proposing to determine that the Columbus, Ohio
area continues to attain the 1997 annual PM2.5 NAAQS.
    On June 3, 2011, OEPA submitted a request for EPA to redesignate
the Columbus area to attainment of the 1997 annual PM2.5
NAAQS and to approve a SIP revision containing emission inventories and
PM2.5 maintenance plan for the area. The maintenance plan
also includes 2022 MVEBs for the Columbus area. In a supplemental
submission to EPA on April 30, 2013, the OEPA submitted 2007 VOC and
ammonia emission inventories to supplement the 2005 primary
PM2.5, SO2, and NOX emission
inventories, included in the June 3, 2011, redesignation request, to
meet the emission inventory requirement of section 172(c)(3) of the
CAA.
    In this proposed rule, EPA takes into account two recent decisions
of the D.C. Circuit. In the first of the two Court decisions, the D.C.
Circuit, on August 21, 2012, issued its decision in EME Homer City
Generation v. EPA, 696 F.3d 7 (D.C. Cir. 2012), which vacated and
remanded CSAPR and ordered EPA to continue administering CAIR ``pending
. . . development of a valid replacement.'' EME Homer City Generation,
696 F.3d at 38. The D.C. Circuit denied all petitions for rehearing on
January 24, 2013.\1\ In the second decision, on January 4, 2013, in
Natural Resources Defense Council v. EPA, the D.C. Circuit remanded to
EPA the ``Final Clean Air Fine Particle Implementation Rule'' (72 FR
20586, April 25, 2007) and the ``Implementation of the New Source Rule
(NSR) Program for Particulate Matter Less than 2.5 Micrometers
(PM2.5)'' final rule (73 FR 28321, May 16, 2008). 706 F.3d
428 (D.C. Cir. 2013).
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    \1\ On March 29, 2013, EPA and other parties filed petitions in
the Supreme Court seeking certiorari of the D.C. Circuit's decision
in EME Homer City. On June 24, 2013, the Supreme Court consolidated
the petitions and granted certiorari. The Supreme Court's decision
to grant the petitions is not a decision on the merits but instead a
decision to review the case on the merits. As such, it does not
alter the current status of CAIR or CSAPR. At this time, CAIR
remains in place.
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IV. What are the criteria for redesignation to attainment?

    The CAA sets forth the requirements for redesignating a
nonattainment area to attainment of a NAAQS. Specifically, section
107(d)(3)(E) of the CAA allows for redesignation provided that: (1) The
Administrator determines that the area has attained the applicable
NAAQS

based on current air quality data; (2) the Administrator has fully
approved an applicable SIP for the area under section 110(k) of the
CAA; (3) the Administrator determines that the improvement in air
quality is due to permanent and enforceable emission reductions
resulting from the implementation of the applicable SIP, Federal air
pollution control regulations and other permanent and enforceable
emission reductions; (4) the Administrator has fully approved a
maintenance plan for the area meeting the requirements of section 175A
of the CAA; and, (5) the state containing the area has met all
requirements applicable to the area for purposes of redesignation under
section 110 and part D of the CAA.

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

A. Has the Columbus area attained the 1997 annual PM2.5
standard?

    In a rulemaking published on September 14, 2011, EPA determined
that the Columbus area had attained the 1997 annual PM2.5
NAAQS by the applicable attainment deadline for this area. The basis
and effect of this determination were discussed in the notices of
proposed (76 FR 28393, May 17, 2011) and final (76 FR 56641, September
14, 2011) rulemaking. The determination was based on quality-assured
air quality monitoring data for 2007-2009 showing that the area has met
the standard. The data have been certified by Ohio.
    In this action, we are proposing to determine that the Columbus
area continues to attain the 1997 annual PM2.5 NAAQS based
on the most recent three years of complete, certified and quality-
assured data, and, therefore, we are proposing to update our
determination of attainment for the Columbus area. Under EPA's
regulations at 40 CFR 50.7, the annual primary (human health-based) and
secondary (environment-based) PM2.5 standards are met when
the annual arithmetic mean concentration, as determined in accordance
with 40 CFR part 50, appendix N, is less than or equal to 15.0 [mu]g/
m\3\ at all relevant monitoring sites in the area. Under 40 CFR part
50, appendix N 4.1, a year of PM2.5 data meets completeness
requirements when at least 75 percent of the scheduled sampling days
for each quarter have valid data.
    EPA has reviewed the ambient air quality monitoring data for the
Columbus area consistent with the requirements contained at 40 CFR part
50. EPA's review focused on Columbus area PM2.5 data quality
assured and certified by the state of Ohio for the period of 2007-2012
and recorded in the EPA Air Quality System (AQS).
    The Columbus area had three PM2.5 monitoring sites with
valid, complete annual PM2.5 data for all three-year periods
considered here. All of these monitoring sites were located in Franklin
County. A fourth PM2.5 monitoring site was located in
Franklin County beginning in 2010, but has yet to monitor complete,
certified annual mean PM2.5 concentrations for a three-year
period. Nevertheless, data measured at this site to date support a
finding of attainment.
    Table 1 summarizes the three-year average annual mean
PM2.5 concentrations (design values) for the three
PM2.5 monitoring sites located in Franklin County for the
three-year periods of 2007-2009, 2008-2010, 2009-2011, and 2010-2012.
These monitors recorded complete PM2.5 data in accordance
with criteria set forth by EPA in 40 CFR part 50, appendix N. Available
data are considered to be sufficient for comparison to the NAAQS if
three consecutive years of data exist.

 Table 1--The Three-Year PM2.5 Design Values for the Columbus, Ohio Area Monitors With Complete, Certified PM2.5
                                          Monitoring Data for 2007-2012
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                                                   PM2.5 Three-    PM2.5 Three-    PM2.5 Three-    PM2.5 Three-
                                                    year design     year design     year design     year design
             County                   Monitor       value 2007-     value 2008-     value 2009-     value 2010-
                                                   2009 ([mu]g/    2010 ([mu]g/    2011 ([mu]g/    2012 ([mu]g/
                                                       m\3\)           m\3\)           m\3\)           m\3\)
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Franklin........................     39-049-0024            13.0            12.5            12.2            11.9
Franklin........................     39-049-0025            12.9            12.2            11.9            11.6
Franklin........................     39-049-0081            11.7            11.3            11.2            11.0
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    EPA's review of monitoring data from the 2007-2009, 2008-2010,
2009-2011, and 2010-2012 monitoring periods supports EPA's
determination that the Columbus area has monitored attainment of the
1997 annual PM2.5 NAAQS for each three-year period
considered (the most recent periods with complete, quality-assured, and
state-certified annual PM2.5 concentrations for this area).
Therefore, EPA proposes to determine that the Columbus area continues
to attain the 1997 annual PM2.5 NAAQS, and EPA proposes to
renew its determination of attainment for the Columbus area.

B. Has the State of Ohio met all requirements of the CAA applicable for
purposes of redesignation of the Columbus area to attainment of the
1997 annual PM2.5 standard?

    We are proposing to find that Ohio has met all currently applicable
SIP requirements for purposes of redesignation for the Columbus area
under section 110 of the CAA (general SIP requirements). We are also
proposing to find that the Ohio SIP meets all SIP requirements
currently applicable for purposes of redesignation under part D of
title I of the CAA, in accordance with section 107(d)(3)(E)(v). We are
proposing to find that all applicable requirements of the Ohio SIP, for
purposes of redesignation, have been approved, in accordance with
section 107(d)(3)(E)(ii) of the CAA. As discussed below, in this
proposed rule, EPA is proposing to approve Ohio's 2005 (primary
PM2.5, SO2, and NOX) and 2007 (VOC and
ammonia) emissions inventories as meeting the requirements of section
172(c)(3) of the CAA for a comprehensive emissions inventory.
    In making these proposed findings, we have ascertained which SIP
requirements are applicable for purposes of redesignation, and have
concluded that there are measures in the Ohio SIP meeting these
requirements. These measures are approved or will be approved by the
time of final rulemaking.

1. Ohio Has Met All Applicable Plan Requirements for Purposes of
Redesignation of the Columbus Area Under Section 110 and Part D of the
CAA
a. Section 110 General SIP Requirements
    Section 110(a) of title I of the CAA contains the general
requirements for a SIP. Section 110(a)(2) provides that the
implementation plan submitted by a state must have been adopted by the
state after reasonable public notice and hearing, and, among other
things, must: (1) Include enforceable emission limitations and other
control measures, means or techniques necessary to meet the
requirements of the CAA; (2) provide for establishment and operation of
appropriate devices, methods, systems and procedures necessary to
monitor ambient air quality; (3) provide for implementation of a source
permit program to regulate the modification and construction of a
stationary source within areas covered by the plan; (4) include
provisions for the implementation of part C, Prevention of Significant
Deterioration (PSD), and part D, New Source Review (NSR), permit
programs; (5) include criteria for stationary source emission control
measures, monitoring and reporting; (6) include provisions for air
quality modeling; and (7) provide for public and local agency
participation in planning and emission control rule development.
    Section 110(a)(2)(D) of the CAA requires that a SIP contain
measures to prevent sources in a state from significantly contributing
to air quality problems in another state. EPA believes that the
requirements linked with a particular nonattainment area's designation
are the relevant measures to evaluate in reviewing a redesignation
request. The transport SIP submittal requirements, where applicable,
continue to apply to a state regardless of the designation of any one
particular area in the state. Thus, we believe that these requirements
should not be construed to be applicable requirements for purposes of
redesignation.
    Further, we believe that the other section 110 elements described
above that are not connected with nonattainment plan requirements and
not linked with an area's attainment status are also not applicable
requirements for purposes of redesignation. A state remains subject to
these requirements after an area is redesignated to attainment. We
conclude that only the section 110 and part D requirements that are
linked with a particular area's designation are the relevant measures
we must consider in evaluating a redesignation request. This approach
is consistent with EPA's existing policy on applicability of conformity
and oxygenated fuels requirements for redesignation purposes, as well
as with section 184 ozone transport requirements. See: Reading,
Pennsylvania proposed and final rulemakings (61 FR 53174-53176, October
10, 1996, and 62 FR 24826, May 7, 1997); Cleveland-Akron-Loraine, Ohio
final rulemaking (61 FR 20458, May 7, 1996); and Tampa, Florida final
rulemaking (60 FR 62748, December 7, 1995). See also the discussion on
this issue in the Cincinnati, Ohio 1-hour ozone redesignation (65 FR
37890, June 19, 2000), and in the Pittsburgh, Pennsylvania 1-hour ozone
redesignation (66 FR 50399, October 19, 2001).
    We have reviewed the Ohio SIP and have concluded that it meets the
general SIP requirements under section 110 of the CAA to the extent
they are applicable for purposes of this redesignation. EPA has
previously approved provisions of Ohio's SIP addressing section 110
requirements, including provisions addressing particulate matter, at 40
CFR 52.1870. On December 5, 2007, and September 4, 2009, Ohio made
submittals addressing ``infrastructure SIP'' elements required under
CAA section 110(a)(2). EPA proposed approval of the December 5, 2007,
submittal on April 28, 2011, at 76 FR 23757, and published final
approval on July 14, 2011, at 76 FR 41075. The requirements of section
110(a)(2), however, are statewide requirements that are not linked to
the PM2.5 nonattainment status of the Columbus area.
Therefore, EPA believes that these SIP elements are not applicable
requirements for purposes of review of the state's PM2.5
redesignation request.
b. Part D Requirements
    EPA is proposing to determine that, upon approval of the base year
emissions inventories discussed below in section V.F of this
rulemaking, the Ohio SIP will meet the SIP requirements for the
Columbus area applicable for purposes of redesignation under part D of
the CAA.
    Subpart 1 of part D, found in sections 172-176 of the CAA, sets
forth the basic nonattainment requirements applicable to all pollutant
nonattainment areas.
Subpart 1 Section 172 Requirements
    For purposes of evaluating this redesignation request, the
applicable section 172 SIP requirements for the Columbus area are
contained in sections 172(c)(1)-(9) of the CAA. A thorough discussion
of these requirements can be found in the General Preamble for
Implementation of Title I (57 FR 13498, April 16, 1992).
    Section 172(c)(1) requires the plans for all nonattainment areas to
provide for implementation of all Reasonably Available Control Measures
(RACM) as expeditiously as practicable and to provide for attainment of
the primary (human health-based) 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. Because attainment has been
achieved in the Columbus area, no additional measures are needed to
provide for attainment, and the section 172(c)(1) requirements are no
longer considered to be applicable as long as the area continues to
attain the standard (becoming permanently not applicable upon final
redesignation of the area to attainment of the 1997 annual
PM2.5 standard, when the area's maintenance plan will
dictate the need for additional emission control measures) (40 CFR
51.1004(c)).
    The Reasonable Further Progress (RFP) requirement under CAA section
172(c)(2) is defined as progress that must be made toward attainment.
This requirement is not relevant for purposes of redesignation because
the Columbus area has monitored attainment of the 1997 annual
PM2.5 NAAQS. See ``State Implementation Plans; General
Preamble for the Implementation of Title I of the Clean Air Amendments
of 1990,'' 57 FR 13498, April 16, 1992, (General Preamble) at 57 FR
13564. See also 40 CFR 51.918. In addition, because the Columbus area
has attained the 1997 annual PM2.5 NAAQS and is no longer
subject to an RFP requirement, the requirement to submit the section
172(c)(9) contingency measures is not applicable for purposes of
redesignation. Id.
    Section 172(c)(3) requires submission and approval of a
comprehensive, accurate and current inventory of actual emissions. Ohio
submitted a 2005 base year emissions inventory for primary
PM2.5, SO2, and NOX emissions along
with their redesignation request, and supplemented these emissions with
a 2007 base year emissions inventory for VOC and ammonia emissions on
April 30, 2013. As discussed below, in section V.F of this proposed
rule, EPA is proposing to approve the 2005 and 2007 base year emissions
inventories as meeting the section 172(c)(3) emission

inventory requirement for the Columbus area.
    Section 172(c)(4) requires the identification and quantification of
allowable emissions for major new and modified stationary sources in an
area, and section 172(c)(5) requires source permits for the
construction and operation of new and modified major stationary sources
in the nonattainment area. EPA approved Ohio's current NSR program on
January 10, 2003 (68 FR 1366). Nonetheless, since PSD requirements will
apply after redesignation, the area need not have a fully-approved NSR
program for purposes of redesignation, provided that the area
demonstrates maintenance of the NAAQS without part D NSR. A detailed
rationale for this view is described in a memorandum from Mary Nichols,
Assistant Administrator for Air and Radiation, dated October 14, 1994,
titled, ``Part D New Source Review Requirements for Areas Requesting
Redesignation to Attainment'' (Nichols memorandum). Ohio has
demonstrated that the Columbus area will be able to maintain the 1997
annual PM2.5 standard without part D NSR in effect in the
Columbus area. Therefore, the state need not have a fully approved part
D NSR program as a condition for the approval of the state's
redesignation request. The state's PSD program will become effective in
the Columbus area upon redesignation of this area to attainment. See
rulemakings for Detroit, Michigan (60 FR 12467-12468, March 7, 1995);
Cleveland-Akron-Lorain, Ohio (61 FR 20458, 20469-20470, May 7, 1996);
Louisville, Kentucky (66 FR 53665, October 23, 2001); and, Grand
Rapids, Michigan (61 FR 31834-31837, June 21, 1996).
    Section 172(c)(6) requires the SIP to contain emission control
measures necessary to provide for attainment of the standard. Because
attainment has been reached, no additional measures are needed to
provide for attainment.
    Section 172(c)(7) requires the SIP to meet the applicable
provisions of section 110(a)(2). As noted above, we believe that Ohio's
SIP meets the requirements of section 110(a)(2) applicable for purposes
of redesignation.
Subpart 1 Section 176(c)(4)(D) Conformity SIP Requirements
    The requirement to determine conformity applies to transportation
plans, programs and projects developed, funded or approved under title
23 of the U.S. Code and the Federal Transit Act (transportation
conformity), as well as to all other federally-supported or funded
projects (general conformity).
    Section 176(c) of the CAA was amended by provisions contained in
the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A
Legacy for Users (SAFETEA-LU), which was signed into law on August 10,
2005 (Pub. L. 109-59). Among the changes Congress made to this section
of the CAA were streamlined requirements for state transportation
conformity SIPs. State transportation conformity regulations must be
consistent with Federal conformity regulations and address three
specific requirements related to consultation, enforcement and
enforceability. EPA believes that it is reasonable to interpret the
transportation conformity SIP requirements as not applying for purposes
of evaluating a redesignation request under section 107(d) for two
reasons.
    First, the requirement to submit SIP revisions to comply with the
transportation conformity provisions of the CAA continues to apply to
areas after redesignation to attainment since such areas would be
subject to section 175A maintenance plans. Second, EPA's Federal
conformity rules require the performance of conformity analyses in the
absence of Federally-approved state rules. Therefore, because areas are
subject to the transportation conformity requirements regardless of
whether they are redesignated to attainment and, because they must
implement conformity under Federal rules if state rules are not yet
approved, EPA believes it is reasonable to view these requirements as
not applying for purposes of evaluating a redesignation request. See
Wall v. EPA, 265 F.3d 426 (6th Cir. 2001), upholding this
interpretation. See also 60 FR 62748, 62749-62750 (December 7, 1995)
(Tampa, Florida).
    Ohio has an approved transportation conformity SIP (72 FR 20945).
2. The Columbus Area Has a Fully Approved Applicable SIP Under Section
110(k) of the CAA
    Upon final approval of Ohio's comprehensive 2005 and 2007 emissions
inventories, EPA will have fully approved the Ohio SIP for the Columbus
area under section 110(k) of the CAA for all requirements applicable
for purposes of redesignation to attainment for the 1997 annual
PM2.5 NAAQS. EPA may rely on prior SIP approvals in
approving a redesignation request (See page 3 of the September 4, 1992,
John Calcagni memorandum, ``Procedures for Processing Requests to
Redesignate Areas to Attainment'' (Calcagni memorandum); Southwestern
Pennsylvania Growth Alliance v. Browner, 144 F.3d 984, 989-990 (6th
Cir. 1998); Wall v. EPA, 265 F.3d 426 (6th Cir. 2001)), plus any
additional measures it may approve in conjunction with a redesignation
action. See 68 FR 25413, 25426 (May 12, 2003). Since the passage of the
CAA in 1970, Ohio has adopted and submitted, and EPA has fully
approved, provisions addressing various required SIP elements under the
particulate matter standards. In this action, EPA is proposing to
approve Ohio's 2005 and 2007 base year emissions inventories for the
Columbus area as meeting the requirement of section 172(c)(3) of the
CAA for the 1997 annual PM2.5 standard.
3. Nonattainment Requirements
    Under section 172, states with nonattainment areas must submit
plans providing for timely attainment and meeting a variety of other
requirements. In 2008, Ohio submitted an attainment demonstration for
PM2.5 for the Columbus area. However, pursuant to 40 CFR
51.1004(c), EPA's determination that the Columbus area has attained the
1997 annual PM2.5 standard suspends the requirement for the
state to submit, and for the EPA to rule on, certain SIP planning
elements related to attainment planning requirements of the CAA,
including attainment demonstration requirements, the Reasonably
Available Control Technology (RACT)-RACM requirements of section
172(c)(1) of the CAA, the RFP and attainment requirements of sections
172(c)(2) and (6) and 182(b)(1) of the CAA, and the contingency measure
requirements of section 172(c)(9) of the CAA.
    As a result, the only remaining requirement under section 172 to be
considered is the emissions inventory requirement under section
172(c)(3) of the CAA. As discussed in section V.F of this proposed
rule, EPA is proposing to approve the 2005 and 2007 emissions
inventories that Ohio submitted along with its redesignation request
and maintenance plan for the Columbus area and in its April 30, 2013,
supplement as satisfying this emissions inventory requirement.
    No Ohio SIP provision applicable for redesignation of the Columbus
area for the 1997 PM2.5 standard is currently disapproved,
conditionally approved or partially approved. If EPA approves Ohio's
Columbus area 2005 and 2007 PM2.5-based emissions
inventories as proposed, Ohio will have a fully approved SIP for all
requirements applicable for purposes of redesignation.

4. Effect of the January 4, 2013, D.C. Circuit Decision Regarding
PM2.5 Implementation Under Subpart 4 of the CAA
a. Background
    As discussed above, on January 4, 2013, in Natural Resources
Defense Council v. EPA, the D.C. Circuit remanded to EPA the ``Final
Clean Air Fine Particle Implementation Rule'' (72 FR 20586, April 25,
2007) and the ``Implementation of the New Source Review (NSR) Program
for Particulate Matter Less than 2.5 Micrometers (PM2.5)''
final rule (73 FR 28321, May 16, 2008) (collectively, ``1997
PM2.5 Implementation Rule''). 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 to
the particulate matter-specific provisions of subpart 4 of part D of
title I.
b. Proposal on This Issue
    In this portion of the proposed redesignation, EPA addresses the
effect of the Court's January 4, 2013, ruling on the proposed
redesignation. As explained below, EPA is proposing to determine that
the Court's January 4, 2013, decision does not prevent EPA from
redesignating the Columbus area to attainment. Even in light of the
Court's decision, redesignation for this area is appropriate under the
CAA and EPA's longstanding interpretations of the CAA's provisions
regarding redesignation. EPA first explains its longstanding
interpretation that requirements that are imposed, or that become due,
after a complete redesignation request is submitted for an area that is
attaining the standard, are not applicable for purposes of evaluating a
redesignation request. Second, EPA then shows that, even if EPA applies
the subpart 4 requirements to Ohio's redesignation request and
disregards the provisions of its 1997 PM2.5 implementation
rule recently remanded by the Court, the state's request for
redesignation of this area still qualifies for approval. EPA's
discussion takes into account the effect of the Court's ruling on the
Columbus area's maintenance plan, which EPA views as approvable when
subpart 4 requirements are considered.
i. Applicable Requirements for Purposes of Evaluating the Redesignation
Request
    With respect to the 1997 PM2.5 Implementation Rule, the
Court's January 4, 2013, ruling rejected EPA's reasons for implementing
the PM2.5 NAAQS solely in accordance with the provisions of
subpart 1, and remanded that matter to EPA, so that it could address
implementation of the 1997 PM2.5 NAAQS under subpart 4 of
part D of the CAA, in addition to subpart 1. For the purposes of
evaluating Ohio's redesignation request for the Columbus 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 Columbus area redesignation.
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 the
Calcagni memorandum. See also ``State Implementation Plan (SIP)
Requirements for Areas Submitting Requests for Redesignation to
Attainment of the Ozone and Carbon Monoxide (CO) National Ambient Air
Quality Standards (NAAQS) on or after November 15, 1992,'' Memorandum
from Michael Shapiro, Acting Assistant Administrator, 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 the
plan and already implemented or due at the time of attainment'').\2\ In
this case, at the time that Ohio submitted its redesignation request,
requirements under subpart 4 were not due, and indeed, were not yet
known to apply.
---------------------------------------------------------------------------

    \2\ Applicable requirements of the CAA that come due subsequent
to the area's submittal of a complete redesignation request remain
applicable until a redesignation is approved, but are not required
as a prerequisite to redesignation. Section 175A(c) of the CAA.
---------------------------------------------------------------------------

    EPA's view that, for purposes of evaluating the Columbus area
redesignation, the subpart 4 requirements were not due at the time the
state submitted the redesignation request is in keeping with the EPA's
interpretation of subpart 2 requirements for subpart 1 ozone
nonattainment areas redesignated subsequent to the D.C. Circuit's
decision in South Coast Air Quality Mgmt. Dist. v. EPA, 472 F.3d 882
(D.C. Cir. 2006). In South Coast, the Court found that EPA was not
permitted to implement the 1997 8-hour ozone standard solely under
subpart 1, and held that EPA was required under the statute to
implement the standard under the ozone-specific requirements of subpart
2 as well. Subsequent to the South Coast decision, in evaluating and
acting upon redesignation requests for the 1997 8-hour ozone standard
that were submitted to EPA for areas under subpart 1, EPA applied its
longstanding interpretation of the CAA that ``applicable
requirements,'' for purposes of evaluating a redesignation, are those
that had been due at the time the redesignation request was submitted.
See, e.g., Proposed Redesignation of Manitowoc County and Door County
Nonattainment Areas (75 FR 22047, 22050, April 27, 2010). In those
actions, EPA, therefore, did not consider subpart 2 requirements to be
``applicable'' for the purposes of evaluating whether the area should
be redesignated under section 107(d)(3)(E).
    EPA's interpretation derives from CAA section 107(d)(3). Section
107(d)(3)(E)(v) states that, for an area to be redesignated, a state
must meet ``all requirements `applicable' to the area under section 110
and part D.'' Section 107(d)(3)(E)(ii) provides that the EPA must have
fully approved the ``applicable'' SIP for the area seeking
redesignation. These two sections read together support EPA's
interpretation of ``applicable'' as only those requirements that came
due prior to submission of a complete redesignation request. First,
holding states to an ongoing obligation to adopt new CAA requirements
that arise after the states submit their redesignation requests, in
order to be redesignated, would make it problematic or impossible for
EPA to act on redesignation requests in accordance with the 18 month
deadline Congress set for EPA action in section 107(d)(3)(D). If
``applicable requirements'' were interpreted to be a continuing flow of
requirements with no reasonable limitation, states, after submitting
redesignation requests, would be forced continuously to make additional
SIP submissions that in turn would require EPA to undertake further
notice-and-comment rulemaking actions to act on those submissions. This
would create a regime of unceasing rulemaking that would delay action
on the

redesignation requests beyond the 18 month timeframe provided by the
CAA for this purpose.
    Second, a fundamental premise for redesignating a nonattainment
area to attainment is that the area has attained the relevant NAAQS due
to emission reductions from existing controls. Thus, an area, for which
a redesignation request has been submitted, would have already attained
the NAAQS as a result of satisfying statutory requirements that came
due prior to the submission of the request. Absent a showing that
unadopted and unimplemented requirements are necessary for future
maintenance, it is reasonable to view the requirements applicable for
purposes of evaluating the redesignation request as including only
those SIP requirements that have already come due. These are the
requirements that led to attainment of the NAAQS. To require, for
redesignation approval, that a state also satisfy additional SIP
requirements coming due after the state submits its complete
redesignation request, and while EPA is reviewing it, would compel the
state to do more than is necessary to attain the NAAQS, without a
showing that the additional requirements are necessary for maintenance.
    In the context of this redesignation, the timing and nature of the
Court's January 4, 2013, decision in NRDC v. EPA compound the
consequences of imposing requirements that come due after the
redesignation request is submitted. The state of Ohio submitted its
redesignation request on June 3, 2011, but the Court did not issue its
decision remanding EPA's 1997 PM2.5 Implementation Rule
concerning the applicability of the provisions of subpart 4 until
January 2013.
    To require the state's fully-completed and pending redesignation
request to comply now with requirements of subpart 4 that the Court
announced only in January 2013, would be to give retroactive effect to
such requirements when the state had no notice that it was required to
meet them. The D.C. Circuit recognized the inequity of this type of
retroactive impact in Sierra Club v. Whitman, 285 F.3d 63 (D.C. Cir.
2002),\3\ where it upheld the District Court's ruling refusing to make
retroactive EPA's determination that the St. Louis area did not meet
its attainment deadline. In that case, petitioners urged the Court to
make EPA's nonattainment determination effective as of the date that
the statute required, rather than the later date on which EPA actually
made the determination. The Court rejected this view, stating that
applying it ``would likely impose large costs on States, which would
face fines and suits for not implementing air pollution prevention
plans . . . even though they were not on notice at the time.'' Id. at
68. Similarly, it would be unreasonable to penalize the state of Ohio
by rejecting its redesignation request for an area that is already
attaining the 1997 PM2.5 standard and that met all
applicable requirements known to be in effect at the time of the
redesignation request. For EPA now to reject the redesignation request
solely because the state did not expressly address subpart 4
requirements, of which it had no notice, would inflict the same
unfairness condemned by the Court in Sierra Club v. Whitman.
---------------------------------------------------------------------------

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

ii. Subpart 4 Requirements and Ohio's Redesignation Request
    Even if EPA were to take the view that the Court's January 4, 2013,
decision requires that, in the context of pending redesignations,
subpart 4 requirements were due and in effect at the time the state
submitted its redesignation request, EPA proposes to determine that the
Columbus area still qualifies for redesignation to attainment. As
explained below, EPA believes that the redesignation request for the
Columbus area, though not expressed in terms of subpart 4 requirements,
substantively meets the requirements of that subpart for purposes of
redesignating the area to attainment.
    With respect to evaluating the relevant substantive requirements of
subpart 4 for purposes of redesignating the Columbus area, EPA notes
that subpart 4 incorporates components of subpart 1 of part D, which
contains general air quality planning requirements for areas designated
as nonattainment. See Section 172(c). Subpart 4 itself contains
specific planning and scheduling requirements for PM10 \4\
nonattainment areas, and, under the Court's January 4, 2013, decision
in NRDC v. EPA, these same statutory requirements also apply to
PM2.5 nonattainment areas. EPA has longstanding general
guidance that interprets the 1990 amendments to the CAA, and which
makes recommendations to states for meeting the statutory requirements
for SIPs addressing nonattainment areas. See General Preamble. In the
General Preamble, EPA discussed the relationship of subpart 1 and
subpart 4 SIP requirements, and pointed out that subpart 1 requirements
were to an extent ``subsumed by, or integrally related to, the more
specific PM-10 requirements.'' 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.
---------------------------------------------------------------------------

    \4\ PM10 refers to particulates nominally 10
micrometers in diameter or smaller.
---------------------------------------------------------------------------

    For the purposes of this redesignation, in order to identify
additional requirements which would apply under subpart 4, we are
considering the Columbus area to be a ``moderate'' PM2.5
nonattainment area. Under section 188 of the CAA, all areas designated
nonattainment areas under subpart 4 would initially be classified by
operation of law as ``moderate'' nonattainment areas, and would remain
moderate nonattainment areas unless and until EPA reclassifies the
areas as ``serious'' nonattainment areas. Accordingly, EPA believes
that it is appropriate to limit the evaluation of the potential impacts
of subpart 4 requirements to those that would be applicable to moderate
nonattainment areas. Sections 189(a) and (c) of subpart 4 apply to
moderate nonattainment areas and include the following: (1) An approved
permit program for construction of new and modified major stationary
sources (section 189(a)(1)(A)); (2) an attainment demonstration
(section 189(a)(1)(B)); (3) provisions for RACM (section 189(a)(1)(C));
and (4) quantitative milestones demonstrating RFP toward attainment by
the applicable attainment date (section 189(c)).
    The permit requirements of subpart 4, as contained in section
189(a)(1)(A), refer to and apply the subpart 1 permit provisions
requirements of sections 172 and 173 to PM10, without adding
to them. Consequently, EPA believes that section 189(a)(1)(A) does not
itself impose for redesignation purposes any additional requirements
for moderate areas beyond those contained in subpart 1.\5\ In any
event, in the context of redesignation, EPA has long relied on the
interpretation that a fully approved nonattainment NSR program is not
considered an applicable requirement for redesignation, provided that
the area can maintain the standard with a PSD program after
redesignation. A detailed

rationale for this view is described in the Nichols memorandum. See
also rulemakings for 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).
---------------------------------------------------------------------------

    \5\ The potential effect of section 189(e) on section
189(a)(1)(A) for purposes of evaluating this redesignation request
is discussed below.
---------------------------------------------------------------------------

    With respect to the specific attainment planning requirements under
subpart 4,\6\ when EPA evaluates a redesignation request under either
subpart 1 and/or 4, any area that is attaining the PM2.5
standard is viewed as having satisfied the attainment planning
requirements for these subparts. For redesignations, EPA has, for many
years, interpreted attainment-linked requirements as not applicable for
areas attaining the standard. In the General Preamble, EPA stated that:
---------------------------------------------------------------------------

    \6\ i.e., attainment demonstration, RFP, RACM, milestone
requirements, and contingency measures.

    The requirements for RFP will not apply in evaluating a request
for redesignation to attainment since, at a minimum, the air quality
data for the area must show that the area has already attained.
Showing that the State will make RFP towards attainment will,
---------------------------------------------------------------------------
therefore, have no meaning at that point.

General Preamble, 57 FR 13498, 13564. The General Preamble also
explained that:

[t]he section 172(c)(9) requirements are directed at ensuring RFP
and attainment by the applicable date. These requirements no longer
apply when an area has attained the standard and is eligible for
redesignation. Furthermore, section 175A for maintenance plans . . .
provides specific requirements for contingency measures that
effectively supersede the requirements of section 172(c)(9) for
these areas.

Id.
    EPA similarly stated in its 1992 Calcagni memorandum that, ``The
requirements for reasonable further progress and other measures needed
for attainment will not apply for redesignations because they only have
meaning for areas not attaining the standard.''
    It is evident that, even if we were to consider the Court's January
4, 2013, decision in NRDC v. EPA to mean that attainment-related
requirements specific to subpart 4 should be imposed retroactively \7\
and, thus, are now past due, those requirements do not apply to an area
that is attaining the 1997 PM2.5 standard, for the purpose
of evaluating a pending request to redesignate the area to attainment.
EPA has consistently enunciated this interpretation of applicable
requirements under section 107(d)(3)(E) since the General Preamble was
published more than twenty years ago. Courts have recognized the scope
of EPA's authority to interpret ``applicable requirements'' in the
redesignation context. See Sierra Club v. EPA, 375 F.3d 537 (7th Cir.
2004).
---------------------------------------------------------------------------

    \7\ As EPA has explained above, we do not believe that the
Court's January 4, 2013, decision should be interpreted so as to
impose these requirements on the states retroactively. Sierra Club
v. Whitman, supra.
---------------------------------------------------------------------------

    Moreover, even outside the context of redesignations, EPA has
viewed the obligations to submit attainment-related SIP planning
requirements of subpart 4 as inapplicable for areas that EPA determines
are attaining the standard. EPA's prior ``Clean Data Policy''
rulemakings for the PM10 NAAQS, also governed by the
requirements of subpart 4, explain EPA's reasoning. They describe the
effects of a determination of attainment on the attainment-related SIP
planning requirements of subpart 4. See ``Determination of Attainment
for Coso Junction Nonattainment Area,'' (75 FR 27944, May 19, 2010).
See also Coso Junction proposed PM10 redesignation, (75 FR
36023, 36027, June 24, 2010); Proposed and Final Determinations of
Attainment for San Joaquin Nonattainment Area (71 FR 40952, 40954-55,
July 19, 2006; and 71 FR 63641, 63643-47 October 30, 2006). In short,
EPA in this context, has also long concluded that to require states to
meet superfluous SIP planning requirements is not necessary and not
required by the CAA, so long as those areas continue to attain the
relevant NAAQS.
    Elsewhere in this notice, EPA proposes to determine that the area
has attained the 1997 PM2.5 standard. Under its longstanding
interpretation, EPA is proposing to determine here that the area meets
the attainment-related plan requirements of subparts 1 and 4.
    Thus, EPA is proposing to conclude that the requirements to submit
an attainment demonstration under 189(a)(1)(B), a RACM determination
under section 172(c)(1) and section 189(a)(1)(c), a RFP demonstration
under 189(c)(1), and contingency measure requirements under section
172(c)(9) are satisfied for purposes of evaluating the redesignation
request.
iii. Subpart 4 and Control of PM2.5 Precursors
    The D.C. Circuit, in NRDC v. EPA, remanded to EPA the two rules at
issue in the case with instructions to EPA to re-promulgate them
consistent with the requirements of subpart 4. EPA, in this section,
addresses the Court's opinion with respect to PM2.5
precursors. While past implementation of subpart 4 for PM10
has allowed for control of PM10 precursors, such as
NOX from major stationary, mobile, and area sources, in
order to attain the standard as expeditiously as practicable, CAA
section 189(e) specifically provides that control requirements for
major stationary sources of direct PM10 shall also apply to
PM10 precursors from those sources, except where EPA
determines that major stationary sources of such precursors ``do not
contribute significantly to PM10 levels which exceed the
standard in the area.''
    EPA's 1997 PM2.5 implementation rule, remanded by the
D.C. Circuit, contained rebuttable presumptions concerning certain
PM2.5 precursors applicable to attainment plans and control
measures related to those plans. Specifically, in 40 CFR 51.1002, EPA
provided, among other things, that a state was ``not required to
address VOC [and ammonia] as . . . PM2.5 attainment plan
precursor[s] and to evaluate sources of VOC [and ammonia] emissions in
the State for control measures.'' EPA intended these to be rebuttable
presumptions. EPA established these presumptions at the time because of
uncertainties regarding the emission inventories for these pollutants
and the effectiveness of specific control measures in various regions
of the country in reducing PM2.5 concentrations. EPA also
left open the possibility for such regulation of VOC and ammonia in
specific areas where that was necessary.
    The Court, in its January 4, 2013, decision, made reference to both
section 189(e) and 40 CFR 51. 1002, and stated that, ``In light of our
disposition, we need not address the petitioners' challenge to the
presumptions in [40 CFR 51.1002] that volatile organic compounds and
ammonia are not PM2.5 precursors, as subpart 4 expressly
governs precursor presumptions.'' NRDC v. EPA, at 27, n.10.
    Elsewhere in the Court's opinion, however, the Court observed:

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

Id. at 21, n.7. For a number of reasons, EPA believes that its proposed
redesignation of the Columbus area is consistent with the Court's
decision with respect to subpart 4. First, while the Court, citing
section 189(e), stated that ``for a PM10 area governed by
subpart 4, a precursor is `presumptively regulated,' '' the Court
expressly declined to decide the specific challenge to EPA's 1997
PM2.5 implementation rule provisions

regarding ammonia and VOC as precursors. The Court had no occasion to
reach whether and how it was substantively necessary to regulate any
specific precursor in a particular PM2.5 nonattainment area,
and did not address what might be necessary for purposes of acting upon
a redesignation request.
    However, even if EPA takes the view that the requirements of
subpart 4 were deemed applicable at the time the state submitted the
redesignation request, and disregards the implementation rule's
rebuttable presumptions regarding ammonia and VOC as PM2.5
precursors, the regulatory consequence would be to consider the need
for regulation of all precursors from any sources in the area to
demonstrate attainment and to apply the section 189(e) provisions to
major stationary sources of precursors. In the case of the Columbus
area, EPA believes that doing so is consistent with proposing
redesignation of the area for the 1997 PM2.5 standard. The
Columbus area has attained the 1997 PM2.5 standard without
any specific additional controls of VOC and ammonia emissions from any
sources in the area.
    Precursors in subpart 4 are specifically regulated under the
provisions of section 189(e), which requires, with important
exceptions, control requirements for major stationary sources of
PM10 precursors.\8\ Under subpart 1 and EPA's prior
implementation rule, all major stationary sources of PM2.5
precursors were subject to regulation, with the exception of ammonia
and VOC. Thus, we must address here whether additional controls of
ammonia and VOC from major stationary sources are required under
section 189(e) of subpart 4 in order to redesignate the area for the
1997 PM2.5 standard. As explained below, we do not believe
that any additional controls of ammonia and VOC are required in the
context of this redesignation.
---------------------------------------------------------------------------

    \8\ 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 to adopt those measures that are deemed reasonably available.
---------------------------------------------------------------------------

    In the General Preamble, EPA discusses its approach to implementing
section 189(e). See 57 FR 13538-13542. With regard to precursor
regulation under section 189(e), the General Preamble explicitly stated
that control of VOC under other CAA 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 proposal, proposes to determine that the
SIP has met the provisions of section 189(e) with respect to ammonia
and VOC as precursors. This proposed determination is based on our
findings that: (1) The Columbus area contains no major stationary
sources of ammonia, and (2) existing major stationary sources of VOC
are adequately controlled under other provisions of the CAA regulating
the ozone NAAQS.\9\ 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 annual PM2.5 standard in this area. See
57 FR 13539-13542.
---------------------------------------------------------------------------

    \9\ The Columbus area has reduced VOC emissions through the
implementation of various control programs including VOC RACT
regulations and various on-road and non-road motor vehicle control
programs.
---------------------------------------------------------------------------

    EPA notes that its 1997 PM2.5 Implementation Rule
provisions in 40 CFR 51.1002 were not directed at evaluation of
PM2.5 precursors in the context of redesignation, but at SIP
plans and control measures required to bring a nonattainment area into
attainment of the 1997 PM2.5 NAAQS. By contrast,
redesignation to attainment primarily requires the area to have already
attained due to permanent and enforceable emission reductions, and to
demonstrate that controls in place can continue to maintain the
standard. Thus, even if we regard the Court's January 4, 2013, decision
as calling for ``presumptive regulation'' of ammonia and VOC for the
control of PM2.5 under the attainment planning provisions of
subpart 4, those provisions do not require additional control of these
precursors for an area that already qualifies for redesignation. Nor
does EPA believe that requiring Ohio to address precursors differently
than they have already done would result in a substantively different
outcome.
    Although, as EPA has emphasized, its consideration here of
precursor requirements under subpart 4 is in the context of a
redesignation to attainment, EPA's existing interpretation of subpart 4
requirements with respect to precursors in attainment plans for
PM10 contemplates that states may develop attainment plans
that regulate only those precursors that are necessary for purposes of
attainment in the area in question, i.e., states may determine that
only certain precursors need to be regulated for attainment and control
purposes.\10\ Courts have upheld this approach to the requirements of
subpart 4 for PM10.\11\ EPA believes that application of
this approach to PM2.5 precursors under subpart 4 is
reasonable. Because the Columbus area has already attained the 1997
PM2.5 NAAQS with its current approach to regulation of
PM2.5 precursors, EPA believes that it is reasonable to
conclude in the context of this redesignation that there is no need to
revisit the attainment control strategy with respect to the treatment
of precursors. Even if the Court's decision is construed to impose an
obligation, in evaluating this redesignation request, to consider
additional precursors under subpart 4, it would not affect EPA's
approval here of Ohio's request for redesignation of the Columbus area.
In the context of a redesignation, the state has shown that the
Columbus area has attained the standard. Moreover, the state has shown
and EPA has proposed to determine that attainment in this area is due
to permanent and enforceable emissions reductions on all precursors
necessary to provide for continued attainment. Therefore, no further
control of additional precursors is necessary. Accordingly, EPA does
not view the January 4, 2013, decision of the Court as precluding
redesignation of the Columbus area to attainment for the 1997
PM2.5 NAAQS at this time.
---------------------------------------------------------------------------

    \10\ See, e.g., ``Approval and Promulgation of Implementation
Plans for California--San Joaquin Valley PM-10 Nonattainment Area;
Serious Area Plan for Nonattainment of the 24-Hour and Annual PM-10
Standards,'' 69 FR 30006 (May 26, 2004) (approving a PM10
attainment plan that imposed controls on direct PM10 and
NOX emissions and that did not impose controls on
SO2, VOC, or ammonia emissions).
    \11\ See, e.g., Assoc. of Irritated Residents v. EPA, 423 F.3d
989 (9th Cir. 2005).
---------------------------------------------------------------------------

    In sum, even if Ohio were required to address precursors for the
Columbus area under subpart 4 rather than under subpart 1, as
interpreted in EPA's remanded 1997 PM2.5 Implementation
Rule, 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).

C. Are the PM2.5 air quality improvements in the Columbus area due to
permanent and enforceable emission reductions?

    For purposes of redesignation, section 107(d)(3)(E)(iii) of the CAA
requires the state to demonstrate that the improvement in air quality
is due to permanent and enforceable emission reductions resulting from
the implementation of the SIP, applicable Federal air pollution control
regulations, and other permanent and enforceable emission reductions.
EPA

finds that Ohio has demonstrated that the observed PM2.5 air
quality improvement in the Columbus area is due to permanent and
enforceable emission reductions. In making this demonstration, Ohio has
determined the change in primary PM2.5, NOX, and
SO2 emissions between 2005, one of the years in which the
Columbus area violated the 1997 annual PM2.5 standard, and
2008, one of the years in which the Columbus area attained the 1997
annual PM2.5 standard. The reduction in emissions and the
corresponding improvement in air quality over this time period can be
attributed to a number of regulatory control measures that have been
implemented in the Columbus area and in surrounding contributing areas.
1. Permanent and Enforceable Emission Controls
    The following is a discussion of permanent and enforceable emission
control measures that have been implemented in the Columbus area and in
upwind areas (resulting in lower pollutant transport into the Columbus
area).
a. Federal Emission Control Measures
    Reductions in PM2.5 precursor emissions have occurred
statewide and in upwind areas as a result of the following Federal
emission control measures. Most of these emission control measures will
result in additional emission reductions in the future.
i. Tier 2 Emission Standards for Vehicles and Gasoline Sulfur Standards
    These emission control requirements result in lower VOC,
NOX, and SO2 emissions from new cars and light-
duty trucks, including sport utility vehicles. The Federal rules were
phased in between 2004 and 2009. The EPA has estimated that, by the
time post-2009 vehicles have entirely replaced pre-2009 vehicles, the
following vehicle NOX emission reductions will occur
nationwide: Passenger cars (light-duty vehicles, 77 percent; light-duty
trucks, minivans, and sport utility vehicles, 86 percent; and, larger
sport utility vehicles, vans, and heavier trucks, 65 to 95 percent. VOC
emission reductions will be approximately 12 percent for passenger
cars, 18 percent for smaller sports utility vehicles, light trucks, and
minivans, and 15 percent for larger sports utility vans, and heavier
trucks. Some of the emission reductions resulting from new vehicle
standards occurred during the 2005-2008 period. Additional emission
reductions occurred subsequent to 2008, and will continue to occur as
the result of this emission control throughout the maintenance period
as new vehicles replace older vehicles. The Tier 2 standards also
reduced the sulfur content of gasoline to 30 parts per million (ppm)
beginning in January 2006. The sulfur content of gasoline is estimated
to be reduced by up to 90 percent by the end of the implementation of
this emission control program.
ii. Heavy-Duty Diesel Engine Rule
    This rule, which EPA issued in July 2000, limits the sulfur content
of diesel fuel and went into effect in 2004. A second phase of
implementation took effect in 2007 and resulted in reduced
PM2.5 emissions from heavy-duty highway diesel engines and
further reduced the highway diesel fuel sulfur content to 15 ppm. The
full implementation of this rule is estimated to achieve a 90 percent
reduction in direct PM2.5 emissions (including direct
emissions of sulfates) and a 95 percent reduction of NOX
emissions for new engines using low sulfur diesel fuel. The reductions
in fuel sulfur content occurred by during the 2007-2009 attainment
period; however, additional emission reductions will continue to occur
throughout the maintenance period as vehicles with older heavy-duty
diesel engines are replaced by vehicles with newer diesel engines. This
rule will also lower SO2 emissions from engines using the
low sulfur diesel fuel, resulting in lower PM2.5 sulfate
concentrations; however, EPA has not estimated the level of this
emission reduction and the level of its impact on PM2.5
concentrations.
iii. Non-Road Diesel Engine Standards
    In May 2004, EPA promulgated a rule to establish emission standards
for large non-road diesel engines, such as those used in construction,
agriculture, or mining operations, and to regulate the sulfur content
in non-road diesel fuel. The engine emission standards in this rule
were to be phased in between 2008 and 2014. This rule reduced the
allowable sulfur content in non-road diesel fuel by over 99 percent.
Prior to 2006, non-road diesel fuel averaged approximately 3,400 ppm in
sulfur content. This rule limits non-road diesel fuel sulfur content to
500 ppm by 2010. The combined engine standards and fuel sulfur content
limits reduced NOX and PM2.5 emissions (including
direct emissions of sulfates) from large non-road diesel engines by
over 90 percent compared to pre-control non-road engines using the
higher sulfur content diesel fuel. This rule achieved all of the
reductions in fuel sulfur content by 2010. Some emission reductions
from the new engine emission standards were realized over the 2007-2009
attainment period, although most of the engine emission reductions will
occur during the maintenance period as the non-road diesel engines are
replaced with newer engines.
iv. Non-Road Spark-Ignition Engines and Recreational Engine Standards
    Although Ohio did not document this Federal emission control
measure in its May 2011 ``Redesignation Request and Maintenance Plan
for the Columbus PM2.5 Nonattainment Area'' nor in the
supplemental emissions submittal, Ohio could have also taken credit for
this permanent and enforceable Federal emission control requirement.
    In November 2002, EPA promulgated emission standards for groups of
previously unregulated non-road engines. These engines include large
spark-ignition engines, such as those used in forklifts and airport
ground-service equipment; recreational vehicles using spark-ignition
engines, such as off-highway motorcycles, all-terrain vehicles, and
snowmobiles; and, recreational marine diesel engines. Emission
standards from large spark-ignition engines were implemented in two
tiers, with Tier 1 starting in 2004 and Tier 2 starting in 2007.
Recreational vehicle emission standards were phased in from 2006
through 2012. Marine diesel engine standards were phased in from 2006
through 2009.
    With full implementation of all of the non-road spark-ignition
engine and recreational engine standards, an overall 72 percent
reduction in VOC, 80 percent reduction in NOX and 56 percent
reduction carbon monoxide (CO) emissions are expected by 2020. Some of
these emission reductions had occurred by the 2008-2010 attainment
period and additional emission reductions will occur during the
maintenance period as the fleets turn over.
b. Control Measures in Upwind Areas
    Given the significance of sulfates and nitrates in the Columbus
area PM2.5 air quality, the area's PM2.5 air
quality is strongly affected by regulation of SO2 and
NOX emissions from power plants in areas upwind of the
Columbus area. The following discusses the emission control regulations
impacting upwind area.
i. NOX SIP Call
    On October 27, 1998 (63 FR 57356), EPA issued a NOX SIP
call requiring the District of Columbia and 22 states to

reduce emissions of NOX. Affected states were required to
comply with Phase I of the NOX SIP call beginning in 2004,
and with Phase II beginning in 2007. NOX emission reductions
resulting from regulations developed in response to the NOX
SIP call area permanent and enforceable. The state of Ohio and other
nearby, upwind states, including Michigan, Indiana, Illinois, and
Kentucky, were subject to the NOX SIP call.
ii. Clean Air Interstate Rule (CAIR) and CSAPR
    EPA proposed CAIR on January 30, 2004, at 69 FR 4566, and
promulgated CAIR on May 12, 2005, at 70 FR 25162, and promulgated
associated Federal Implementation Plans (FIPs) on April 28, 2006, at 71
FR 25328, in order to reduce SO2 and NOX
emissions and improve air quality in areas across Eastern United
States. However, on July 11, 2008, the D.C. Circuit vacated and
remanded both CAIR and the associated CAIR FIPs in their entirety. See
North Carolina v. EPA, 531 F.3d 836 (D.C. Cir. 2008). EPA petitioned
for a rehearing, and the D.C. Circuit issued an order remanding CAIR
and the CAIR FIPs to EPA without vacatur. See North Carolina v. EPA,
550 F.3d 1176 (D.C. Cir. 2008). The D.C. Circuit, thereby, left CAIR in
place in order to ``temporarily preserve the environmental values
covered by CAIR'' until EPA replaced it with a rule consistent with the
Court's opinion. Id. at 1178. The Court directed EPA to ``remedy CAIR's
flaws'' consistent with the July 11, 2008, opinion, but declined to
impose a schedule on EPA for completing this action. Id.
    EPA recently promulgated CSAPR (76 FR 48208, August 8, 2011) to
replace CAIR, which, as noted above, had been in place since 2005. See
76 FR 59517. CSAPR required significant reductions in emissions of
SO2 and NOX from electric generating units to
limit the interstate transport of these pollutants and the ozone and
fine particulate matter they form in the atmosphere. See 76 FR 70093.
    On December 30, 2011, the D.C. Circuit issued an order addressing
the status of CSAPR and CAIR in response to motions filed by numerous
parties seeking a stay of CSAPR pending judicial review. In that order,
the Court stayed CSAPR pending resolution of the petitions for review
of that rule in EME Homer City Generation v. EPA (No. 11-1302 and
consolidated cases). The Court also indicated that EPA was expected to
continue to administer CAIR in the interim until judicial review of
CSAPR as completed.
    On August 21, 2012, the D.C. Circuit issued a decision to vacate
CSAPR. In that decision, it also ordered EPA to continue administering
CAIR ``pending the promulgation of a valid replacement.'' EME Homer
City Generation, 696 F.3d at 38. The D.C. Circuit denied all petitions
for rehearing on January 24, 2013. EPA and other parties have filed
petitions for certiorari to the U.S. Supreme Court. As noted above, on
June 24, 2013, the Supreme Court consolidated the petitions and granted
certiorari (granted review as requested by these petitions).
Nonetheless, EPA intends to continue to act in accordance with the EME
Homer City Generation opinion.
    In light of these unique circumstances and for the reasons
explained below, to the extent that attainment is due to emission
reductions associated with CAIR, EPA is proposing to determine that
those emission reductions are sufficiently permanent and enforceable
for purposes of CAA section 107(d)(3)(E)(iii) (and for purposes of
assessing maintenance of the 1997 annual PM2.5 standard in
the Columbus area, as discussed below, for CAA section 175A).
2. Emission Reductions
a. Ohio's Demonstration That Significant Emission Reductions Have
Occurred in the Columbus Area and in Upwind Areas
    To demonstrate that significant emission reductions have resulted
in attainment, Ohio EPA compared the Columbus area NOX,
SO2, and primary PM2.5 emissions for 2005 with
those of 2008. As noted above, the 2008 emissions represent those for a
year in which the Columbus area was attaining the 1997 annual
PM2.5 standard (2008 is the middle year of the 2007-2009
period in which the Columbus area initially attained the 1997 annual
PM2.5 standard), and 2005 represents a year in which the
Columbus area was violating this standard.
    The derivation of the 2005 (base year) emissions is discussed in
more detail below in section V.F of this proposed rule. The derivation
of the 2008 (attainment year) emissions is discussed in more detail
here.
    The 2008 emissions were based on actual source activity levels. The
point source emissions were compiled from Ohio's annual emissions
reports, submitted to the OEPA by individual source facilities for all
non-Electric Generating Unit (non-EGU) sources, and EGU emissions
projected from the 2005 EPA Air Market's acid rain database. Area
source emissions were taken from the Ohio 2005 periodic inventory and
were projected to 2008 using Department of Commerce Bureau of Economic
Analysis (BEA) growth factors and some updated local information. Area
source emissions were calculated using the most recently available
emission calculation methodologies, and source activity data
(population, employment by source sector, fuel use, etc.) specific to
2008. On-road mobile source emissions were calculated using EPA's
MOVES2010 emissions model with 2008 Vehicle Miles Traveled (VMT) and
other vehicle data (roadway speeds, vehicle type and age distribution,
etc.) provided by the Mid-Ohio Regional Planning Commission (MORPC) and
Ohio Department of Transportation (ODOT). Non-road mobile source
emissions were generated using EPA's National Mobile Inventory Model
(NMIM) 2002 application and source activity data projected to 2008.
Emissions for aircraft, commercial marine vessels, and railroads were
derived separately by contractors under the direction of the Lake
Michigan Air Directors Consortium (LADCO). Spatial surrogates were used
to allocate emissions to individual counties. Biogenic emissions were
not calculated since these emissions are assumed to remain constant
over time (biogenic emissions are not included in the 2002, 2008, 2015,
and 2022 emissions summarized in this proposed rule).
    The 2005 and 2008 emissions for NOX, SO2, and
primary PM2.5 for the Columbus area are summarized in tables
2 through 4 below. All emissions are in units of tons per year (TPY).
All summarized emissions are documented in Ohio's May 2011
``Redesignation Request and Maintenance Plan For the Columbus Annual
PM2.5 Nonattainment Area.''

         Table 2--Comparison of 2005 and 2008 NOX Emission Totals for the Columbus Area by Source Sector
                                                      [TPY]
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                          Source sector                                2005            2008          2005-2008
----------------------------------------------------------------------------------------------------------------
Point Sources...................................................       25,188.87       24,373.96         -814.91
Area Sources....................................................         5,467.2        5,534.32           67.12
On-Road Mobile Sources..........................................       53,390.61       44,825.81       -8,564.80
Off-Road Mobile Sources.........................................       14,609.69       12,728.47       -1,881.22
                                                                 -----------------------------------------------
    Total.......................................................       98,656.37       87,462.56      -11,193.81
----------------------------------------------------------------------------------------------------------------

    Table 3--Comparison of 2005 and 2008 Primary PM2.5 Emission Totals for the Columbus Area by Source Sector
                                                      [TPY]
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                          Source sector                                2005            2008          2005-2008
----------------------------------------------------------------------------------------------------------------
Point Sources...................................................        1,478.64        1,553.83           75.19
Area Sources....................................................        1,552.43        1,620.06           67.63
On-Road Mobile Sources..........................................        1,660.33        1,451.09         -209.24
Off-Road Mobile Sources.........................................        1,058.53          908.32         -150.21
                                                                 -----------------------------------------------
    Total.......................................................        5,749.93         5,533.3         -216.63
----------------------------------------------------------------------------------------------------------------

         Table 4--Comparison of 2005 and 2008 SO2 Emission Totals for the Columbus Area by Source Sector
                                                      [TPY]
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                          Source sector                                2005            2008          2005-2008
----------------------------------------------------------------------------------------------------------------
Point Sources...................................................      111,266.53       94,553.48      -16,713.05
Area Sources....................................................          566.95          563.68           -3.27
On-Road Mobile Sources..........................................          864.22          283.05         -581.17
Off-Road Mobile Sources.........................................        1,603.24          729.80         -873.44
                                                                 -----------------------------------------------
    Total.......................................................      114,300.88       96,130.01      -18,170.87
----------------------------------------------------------------------------------------------------------------

    Tables 2 through 4 show that NOX, SO2, and
primary PM2.5 emissions in the Columbus area have been
reduced significantly between the 2005 violation year and the 2008
attainment year.
    In addition to the local PM2.5 precursor emission
reductions, we believe that regional NOX and SO2
emission reductions resulting from the implementation of EPA's Acid
Rain Program (ARP) (see 40 CFR parts 72 through 78), NOX SIP
call, and CAIR have significantly contributed to the PM2.5
air quality improvement in the Columbus area. To assess the change in
regional emissions from states believed to significantly contribute to
annual PM2.5 concentrations in the Columbus area, OEPA has
considered the change in EGU NOX and SO2
emissions from Ohio and surrounding states between 2008 and 2009. Table
5 shows the reduction in NOX and SO2 emissions
for EGUs in Ohio, the LADCO states (Illinois, Indiana, Michigan, Ohio,
and Wisconsin), and nationwide (these data are taken from table 9, page
23 of OEPA's May 2011 redesignation and maintenance plan).

                                                   Table 5--Statewide EGU Emissions for 2008 and 2009
                                                                          [TPY]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                NOX                                             SO2
                                                         -----------------------------------------------------------------------------------------------
                          Area                                                                Percent                                         Percent
                                                               2008            2009          reduction         2008            2009          reduction
--------------------------------------------------------------------------------------------------------------------------------------------------------
Ohio....................................................         235,018          96,351              59         709,444         601,101              15
LADCO States............................................         702,384         393,930              44       2,019,036       1,620,071              20
Nationwide..............................................       2,996,385       1,990,385              34       7,616,262       5,747,353              25
--------------------------------------------------------------------------------------------------------------------------------------------------------

    As can be seen in table 5, the implementation of CAIR (the primary
additional regional emissions control implemented during the 2008-2009
period) resulted in significant reductions in Ohio, regional, and
nationwide NOX and SO2 emissions from EGUs, all
of which OEPA believes contributed to attainment of the 1997 annual
PM2.5 standard in the Columbus area. Since CAIR remains in
place until EPA can replace it with an acceptable new state region-wide
emissions control rule, we believe these emission

reductions to be permanent and enforceable.
    The information summarized above shows that emissions of
PM2.5 and its most significant precursors (SO2
and NOX) have significantly decreased between 2005 and 2009
in the Columbus area and in states with EGU emissions significantly
impacting the annual PM2.5 concentrations in the Columbus
area.
b. VOC and Ammonia Emission Reductions
    For several reasons we believe that VOC emission reductions in the
Columbus area and in upwind states have also contributed to the
observed improvement in annual PM2.5 concentrations in the
Columbus area. In addition, for several reasons, we also believe that
changes in ammonia emissions have not significantly impacted the
observed annual PM2.5 concentrations in this area.
    First, as noted elsewhere in this proposed rule in EPA's discussion
of section 189(e) of the CAA, VOC emissions in the Columbus area have
historically been well-controlled under SIP requirements related to
ozone and other pollutants.\12\ Second, total ammonia emissions
throughout the Columbus area are very low, estimated to be 6,101.37 TPY
in 2007. See the discussion of 2007 VOC and ammonia emissions below.
This amount of ammonia emissions appears especially small in comparison
to the total amounts of SO2 and NOX emissions
sources in the area in 2005. Third, as described below, available
information shows that no PM2.5 precursor, including VOC and
ammonia, is expected to increase over the maintenance period so as to
interfere with or undermine the state's maintenance demonstration.
---------------------------------------------------------------------------

    \12\ For a thorough discussion of VOC emission controls and
estimates (2002 and 2004) and projected (2009 and 2018) VOC emission
levels (summertime emissions) in the Columbus area, see EPA's
proposed rule for the redesignation of the Columbus area to
attainment of the 1997 8-hour ozone standard (72 FR 32257, June 12,
2007). We observe here that the estimated/projected summertime VOC
emission reductions in the Columbus area also generally reflect
reductions in annual emissions of VOC in this area.
---------------------------------------------------------------------------

c. Conclusions Regarding Emission Reductions Between 2005 and 2008 in
the Columbus Area
    From the above, it is concluded that SO2,
NOX, primary PM2.5, and VOC emissions were well
controlled between 2005 and 2008 and that significant reductions in the
emissions of these pollutants occurred in the Columbus area during this
period. During the same period, emissions of ammonia are believed to
have had minimal impact on PM2.5 concentrations in the
Columbus area. We believe that the emission reductions of the
significant PM2.5 precursors, including primary
PM2.5, in the Columbus area and in upwind states are
responsible for the observed improvement in annual PM2.5
concentrations in the Columbus area. Based on this observation, we
conclude that the attainment of the 1997 annual PM2.5
standard in the Columbus area can be explained on the basis of
permanent and enforceable emission reductions within the Columbus area
and in the states regulated by CAIR and NOX SIP call
regulations.

D. Does Ohio have a fully approvable PM2.5 maintenance plan pursuant to
Section 175A of the CAA for the Columbus area?

    In conjunction with Ohio's request to redesignate the Columbus area
to attainment of the 1997 annual PM2.5 standard, OEPA
submitted a SIP revision to provide for maintenance of the 1997 annual
PM2.5 standard in the Columbus area through 2022. This
maintenance plan demonstrates that emissions in the Columbus area are
projected to remain at or below the attainment levels throughout the
maintenance period and provides for corrective action should the 1997
annual standard be violated or threatened in the Columbus area during
the maintenance period. The following summarizes the details of the
maintenance plan and maintenance demonstration.
1. What is required in a maintenance plan?
    Sections 107(d)(3)(E)(iv) and 175A of the CAA require that states
demonstrate that the areas to be redesignated will continue to meet the
PM2.5 NAAQS for at least 10 years after EPA approves the
redesignation of the areas to attainment of the NAAQS. Section 175A of
the CAA sets forth the required elements of a maintenance plan. Under
section 175A, a state must also commit to submit a revised maintenance
plan within eight years after redesignation to provide for maintenance
of the standard for an additional 10 years after the initial 10-year
maintenance period. To address the possibility of future NAAQS
violations, the maintenance plan must contain contingency measures with
a schedule for implementation as EPA deems necessary to assure prompt
correction of any future violations of the standard.
    The Calcagni memorandum provides additional guidance on the content
of a maintenance plan. The memorandum states that a maintenance plan
should address the following items: The attainment emission
inventories; a maintenance demonstration showing maintenance of the
standard for the 10 years of the maintenance period; a commitment to
maintain the existing monitoring network; documentation of the factors
and procedures to be used for verification of continued attainment of
the standard; and, a contingency plan to prevent or correct future
violations of the standard.
2. Attainment Inventory
    The OEPA developed NOX, SO2, and primary
PM2.5 emission inventories for 2008, one of the years used
to demonstrate monitored attainment of the 1997 annual PM2.5
standard. These emission levels are defined to be the attainment levels
of the emissions. The 2008 attainment levels of the emissions are
summarized in tables 3 through 5 above and in tables 6 through 8 below.
3. Demonstration of Maintenance
a. State Demonstration of Maintenance
    Along with the redesignation request, OEPA submitted a revision of
the Ohio PM2.5 SIP to include a demonstration of maintenance
for the Columbus area, as required by section 175A of the CAA. This
demonstration shows maintenance of the 1997 annual PM2.5
standard through 2022 by showing that current and future emissions of
NOX, SO2, and primary PM2.5 for the
Columbus area will remain at or below attainment year emission levels.
A maintenance demonstration may be based on such an emissions inventory
approach. See Wall v. EPA, 265 F.3d 426 (6th Cir. 2001), Sierra Club v.
EPA, 375 F.3d 537 (7th Cir. 2004). See also 66 FR 53094, 53099-53100
(October 19, 2001), 68 FR 25413, 25430-25432 (May 12, 2003).
    OEPA used emission projections for 2015 and 2022 to demonstrate
maintenance. For primary PM2.5, SO2, and
NOX, OEPA prepared emission estimates for the same source
sectors used for the attainment year emission estimates. As for the
base year and attainment year, biogenic emissions were assumed to
remain constant, and were not considered in the maintenance
demonstration analysis.
    As done for the 2005 and 2008 mobile source emissions, OEPA used
EPA's MOVES2010 mobile source model and projected traffic levels and
other related mobile source factors to estimate on-road mobile source
emissions for the maintenance demonstration years. The on-road mobile
source emission projections were developed assuming

the continued phase-in of the Federal motor vehicle emission standards.
Total VMT and other on-road vehicle data for 2015 and 2022 were derived
using the same modeling systems (with projected input data population,
population distribution, etc.) used to derive the 2005 and 2008 on-road
mobile source emissions. As with the 2005 and 2008 on-road mobile
source emissions, EPA's MOVES2010 model was used to calculate mobile
source emission factors. The 2015 and 2022 on-road mobile source
emissions were used to establish MVEBs for the Columbus area. See the
additional discussion of the MVEBs in section V.E of this proposed
rule.
    Columbus area point and area source emissions for 2015 and 2022
were estimated using the 2008 attainment year emissions and growth
factors for each source category within each source sector. Emission
growth factors were provided by LADCO.
    Tables 6 through 8 summarize the projected NOX,
SO2, and primary PM2.5 emissions for 2008, 2015
and 2022 by source sector in the Columbus area.

     Table 6--Comparison of 2008, 2015, and 2022 NOX Emissions by Source Sector (TPY) for the Columbus Area
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                  Source sector                        2008            2015            2022          2008-2022
----------------------------------------------------------------------------------------------------------------
Point Sources...................................       24,373.96       13,159.20        7,627.51      -16,746.45
Area Sources....................................        5,534.32        5,577.77        5,631.84           97.52
On-Road Mobile..................................       44,825.81       21,812.27       10,597.83      -34,227.98
Off-Road Mobile.................................       12,728.47        8,113.60        3,519.93       -9,208.54
                                                 ---------------------------------------------------------------
    Totals......................................       87,462.56       48,662.84       27,377.11      -60,085.45
----------------------------------------------------------------------------------------------------------------

     Table 7--Comparison of 2008, 2015, and 2022 SO2 Emissions by Source Sector (TPY) for the Columbus Area
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                  Source sector                        2008            2015            2022          2008-2022
----------------------------------------------------------------------------------------------------------------
Point Sources...................................       94,553.48       44,636.32       23,258.56      -71,294.92
Area Sources....................................          563.68          548.39           533.8          -29.88
On-Road Mobile..................................          283.05          128.37          124.45         -158.60
Off-Road Mobile.................................          729.80          259.63          149.42         -580.38
                                                 ---------------------------------------------------------------
    Totals......................................       96,130.01       45,572.71       24,066.23      -72,063.78
----------------------------------------------------------------------------------------------------------------

Table 8--Comparison of 2008, 2015, and 2022 Primary PM2.5 Emissions by Source Sector (TPY) for the Columbus Area
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                  Source sector                        2008            2015            2022          2008-2022
----------------------------------------------------------------------------------------------------------------
Point Sources...................................        1,553.83        1,647.99        1,745.63          191.80
Area Sources....................................        1,620.06        1,623.79        1,627.88            7.82
On-Road Mobile..................................        1,451.09          759.53           486.2         -964.89
Off-Road Mobile.................................          908.32          613.95          314.31         -594.01
                                                 ---------------------------------------------------------------
    Totals......................................        5,533.30        4,645.26        4,174.02       -1,359.28
----------------------------------------------------------------------------------------------------------------

    Comparison of the 2008 and projected 2015 and 2022 emissions
demonstrates that future NOX, SO2, and primary
PM2.5 emissions through 2022 will remain below the 2008
levels in the Columbus area. EPA concludes that Ohio had demonstrated
maintenance of the 1997 annual PM2.5 standard in the
Columbus area. In addition, for the reasons set forth below, EPA
believes that Ohio's submissions, in conjunction with additional
supporting information, further demonstrate that the Columbus area will
continue to maintain the 1997 annual PM2.5 standard at least
through 2023. Thus, in anticipation that EPA will complete action on
Ohio's redesignation request and maintenance plan in 2013, EPA proposes
to conclude that the state's maintenance plan provides for maintenance
for the requisite ten years after redesignation, in accordance with
section 175A of the CAA.
    The rates of decline in emissions of primary PM2.5,
NOX, and SO2 emissions from the attainment year,
2008, through 2022 documented in Ohio's maintenance demonstration
indicate that emission levels will not only significantly decline
between 2008 and 2022, but that reductions in emissions (relative to
2008 levels) will continue through 2023 and beyond. The projected
average annual rates of decline are 4,292 TPY per year for
NOX, 5,147 TPY per year for SO2, and 97 TPY per
year for primary PM2.5. These rates of decline are
consistent with monitored and projected air quality trends and with
emission reductions achieved through emissions controls and regulations
that will remain in place through 2023. Furthermore, fleet turnover in
on-road and non-road vehicles that will continue to occur after 2022
will provide additional significant emission reductions.
    In addition, as table 1 demonstrates, monitored PM2.5
design value concentrations in the Columbus area are well below the
NAAQS in the years beyond 2008. These PM2.5 design values
are trending downward as time progresses. Based on the future
projections of emissions in 2015 and 2022, which show significant
emission

reductions in primary PM2.5, NOX, and
SO2, it is very unlikely that monitored PM2.5
concentrations in 2023 and beyond will show violations of the 1997
annual PM2.5 standard. The 2010-2012 p.m.2.5 design values
documented in table 1, coupled with the projected drops in
PM2.5 precursor emissions, imply that there will be a
PM2.5 attainment margin in the Columbus area sufficient to
buffer against violations of the 1997 annual PM2.5 standard
in the unlikely event that emissions rise slightly in the future
between 2022 and 2023.
b. CAIR and CSAPR
i. Background--Effect of the August 21, 2012, D.C. Circuit Decision
Regarding EPA's CSAPR
    EPA recently promulgated CSAPR (76 FR 48208, August 8, 2011) to
replace CAIR, which has been in place since 2005. See 76 FR 59517. CAIR
requires significant reductions in emissions of SO2 and
NOX from EGUs to limit the interstate transport of these
pollutants and the ozone and PM2.5 they form in the
atmosphere. See 76 FR 70093. The D.C. Circuit initially vacated CAIR,
North Carolina v. EPA, 531 F.3d 896 (D.C. Cir. 2008), but ultimately
remanded that 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).
    CSAPR included regulatory changes to sunset (i.e., discontinue)
CAIR and CAIR FIPs for control periods in 2012 and beyond. See 76 FR
48322. Although the Columbus area redesignation request and Ohio's
PM2.5 maintenance plan do not rely on emission reductions
associated with CAIR, EPA notes that it is proposing to approve the
redesignation request and PM2.5 maintenance plan based, in
part, on the fact that CAIR is to remain in place until it is replaced
by an acceptable interstate transport control rule.
    On December 30, 2011, the D.C. Circuit issued an order addressing
the status of CSAPR and CAIR in response to motions filed by numerous
parties seeking a stay of CSAPR pending judicial review. In that order,
the Court stayed CSAPR pending resolution of the petitions for review
of that rule in EME Homer City (No. 11-1302 and consolidated cases).
The Court also indicated that EPA was expected to continue to
administer CAIR in the interim until judicial review of CSAPR was
completed.
    On August 21, 2012, the D.C. Circuit issued the decision in EME
Homer City to vacate and remand CSAPR and ordered EPA to continue
administrating CAIR ``pending . . . development of a valid
replacement.'' EME Homer City, 696 F.3d at 38. The D.C. Circuit denied
all petitions for rehearing on January 24, 2013. EPA and other parties
then filed petitions for certiorari to the U.S. Supreme Court, which
the Supreme Court granted on June 24, 2013. Nonetheless, EPA intends to
continue to act in accordance with the EME Homer City opinion.
    In light of these unique circumstances and for the reasons
explained below, to the extent that attainment and maintenance is due
to emission reductions associated with CAIR, EPA is here determining
that those reductions are sufficiently permanent and enforceable for
purposes of CAA sections 107(d)(3)(E)(iii) and 175A.
    As directed by the D.C. Circuit, CAIR remains in place and
enforceable until EPA promulgates a valid replacement rule to
substitute for CAIR. As noted above, the Columbus area PM2.5
redesignation request and maintenance plan does not rely on the
emission reductions from CAIR, but attainment of 1997 annual
PM2.5 standard in the Columbus area did result, in part,
from the implementation of CAIR and CAIR will contribute to maintenance
in the future. Ohio submitted a CAIR SIP, which was approved by EPA on
February 1, 2008 (73 FR 6034). On July 15, 2009, Ohio submitted
revisions to its CAIR SIP, which EPA approved on September 25, 2009 (74
FR 48857). In its redesignation request, Ohio notes that in 2009
facilities began implementing control programs to address CAIR, and
that CAIR will provide significant reductions in NOX,
SO2, primary PM2.5 emissions until such time as
it is replaced by a new transport rule. CAIR was, thus, in place and
getting emission reductions when the Columbus area was monitoring
attainment of the 1997 annual PM2.5 standard during the
2008-2012 period.
    To the extent that Ohio is relying on CAIR to support continued
attainment in the Columbus area, the recent directive from the D.C.
Circuit in EME Homer City ensures that the emission reductions
associated with CAIR will be permanent and enforceable for the
necessary time period. EPA has been ordered by the Court to develop a
new rule to address interstate transport to replace CSAPR and the
opinion makes clear that after promulgating that new rule EPA must
provide states an opportunity to draft and submit SIPs to implement
that rule. Thus, CAIR will remain in place until EPA has promulgated a
final rule through a notice-and-comment rulemaking process, states have
had an opportunity to draft and submit SIPs in response to it, EPA has
reviewed the SIPs to determine if they can be approved, and EPA has
taken action on the SIPs, including promulgating FIPs if appropriate.
The Court's clear instruction to EPA is that it must continue to
administer CAIR until a valid replacement exists, and thus EPA believes
that CAIR emission reductions may be relied upon until the necessary
actions are taken by EPA and states to administer CAIR's replacement.
Furthermore, the Court's instruction provides an additional backstop:
By definition, any rule that replaces CAIR and meets the Court's
direction would require upwind states to have SIPs that eliminate any
significant contributions to downwind nonattainment and prevent
interference with maintenance in downwind areas.
    Moreover, in vacating CSAPR and requiring EPA to continue
administering CAIR, the D.C. Circuit emphasized that the consequences
of vacating CAIR ``might be more severe now in light of the reliance
interests accumulated over the intervening four years.'' EME Homer
City, 696 F.3d at 38. The reliance interests accumulated include the
interests of states that reasonably assumed they could rely on
reductions associated with CAIR which brought certain nonattainment
areas into attainment with the NAAQS. If EPA were prevented from
relying on reductions associated with CAIR in redesignation actions,
states would be forced to impose additional, redundant reductions on
top of those achieved by CAIR. EPA believes this is precisely the type
of irrational result the Court sought to avoid by ordering EPA to
continue administering CAIR. For these reasons also, EPA believes it is
appropriate to allow states to rely on CAIR, and the existing emissions
reductions achieved by CAIR, as sufficiently permanent and enforceable
for regulatory purposes, such as redesignations. Following promulgation
of the replacement rule for CSAPR, EPA will review existing SIPs as
appropriate to identify whether there are any issues that need to be
addressed.
ii. Maintenance Plan Precursor Evaluation Resulting From Court
Decisions
    With regard to the redesignation of the Columbus area, in
evaluating the effect of the Court's remand of EPA's implementation
rule, which included presumptions against consideration of VOC and
ammonia as PM2.5 precursors, EPA in this proposal is also
considering the impact of the decision on the

maintenance plan required under sections 175A and 107(d)(3)(E)(iv) of
the CAA. To begin with, EPA notes that the area has attained the 1997
annual PM2.5 standard and that the state has shown that
attainment of this standard is due to permanent and enforceable
emission reductions, as noted above.
    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 annual
PM2.5 standard in the Columbus 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 on documentation provided by the state and
supporting information, EPA believes that the maintenance plan for the
Columbus area need not include any additional emission reductions of
VOC or ammonia in order to provide for continued maintenance of the
standard.
    Emissions inventories used in the Regulatory Impact Analysis (RIA)
for the 2012 p.m.2.5 NAAQS show that VOC and ammonia emissions in the
Columbus area are projected to decrease by 19,358 TPY and 119 TPY,
respectively, between 2007 and 2020. See table 9 below. While the RIA
emissions inventories are only projected to 2020, there is no reason to
believe that the projected downward trends would not continue through
2023. Given that the Columbus area is already attaining the 1997 annual
PM2.5 standard, even with the current levels of VOC and
ammonia emissions in this area, the downward trends in VOC and ammonia
would be consistent with continued attainment of the 1997 annual
PM2.5 standard in the Columbus area. Indeed, projected
emission reductions for PM2.5 precursors that the state has
addressed for purposes of the 1997 annual PM2.5 standard
(see tables 6 through 8 above) also indicate that the Columbus area
should continue to attain the NAAQS following the precursor control
strategies that the state of Ohio and other upwind states have already
elected to pursue. Even if ammonia emissions were to increase
unexpectedly between 2020 and 2023, the overall emissions reductions
projected in SO2, NOX, primary PM2.5,
and VOC (see 72 FR 32257, June 12, 2009) would be sufficient to offset
the increase in annual PM2.5 concentrations resulting from
the hypothetical increase in ammonia emissions. For these reasons, EPA
believes that even a reversal of the downward trend in local emissions
of ammonia (and VOC) would not cause monitored PM2.5 levels
to violate the 1997 annual PM2.5 standard during the
maintenance period.

 Table 9--Comparison of 2007 and 2020 VOC and Ammonia Emissions Totals by Source Sector (TPY) for the Columbus Area Based on RIA Emissions Estimates for
                                                                  the 2012 PM2.5 NAAQS
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                VOC                                           Ammonia
                                                         -----------------------------------------------------------------------------------------------
                      Source sector                                                         Net change                                      Net change
                                                               2007            2020          2007-2020         2007            2020          2007-2020
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fires...................................................           77.48           77.48             0.0            5.62            5.62             0.0
Area....................................................       20,305.24       20,643.97          338.73        4,640.75        4,853.36          212.61
Non-Road Mobile.........................................        7,574.55        4,381.79       -3,192.76           11.20           12.80             1.6
On-Road Mobile..........................................       25,006.05        8,430.70      -16,575.35          807.16          423.61         -383.55
Point...................................................        1,423.57        1,495.24           71.67          242.31          292.41            50.1
                                                         -----------------------------------------------------------------------------------------------
    Totals..............................................       54,386.89       35,029.18      -19,357.71        5,707.04        5,587.80         -119.24
--------------------------------------------------------------------------------------------------------------------------------------------------------

c. EPA's Conclusion for Ohio's Maintenance Demonstration
    Based on the information summarized above, we conclude that Ohio
has adequately demonstrated maintenance of the 1997 annual
PM2.5 standard in the Columbus area for a period of ten
years from the time that EPA may be expected to complete rulemaking on
the state's PM2.5 redesignation request.
4. Monitoring Network
    Ohio commits to continue monitoring PM2.5 levels
according to the EPA-approved monitoring plan during the maintenance
period, as required to ensure maintenance of the 1997 annual
PM2.5 standard. If changes are needed in the
PM2.5 monitoring network, OEPA will work with the EPA to
ensure the adequacy of the monitoring network.
5. Verification of Continued Attainment
    Continued attainment of the 1997 annual PM2.5 standard
in the Columbus area depends, in part, on the state's efforts toward
tracking indicators of continued attainment during the maintenance
period. Ohio's plan for verifying continued attainment of the standard
in the Columbus area consists of continued ambient PM2.5
monitoring in accordance with the requirements of 40 CFR part 58 and
continued tracking of emissions through periodic updates of the
PM2.5 and PM2.5 precursor emissions inventory for
the Columbus area, as required by the Federal Consolidated Emission
Reporting Rule (codified at 40 CFR part 51 subpart A).
6. Contingency Plan
    The contingency plan provisions are designed to correct, as
expeditiously as possible, or prevent a violation of the 1997 annual
PM2.5 standard that might occur after redesignation of an
area to attainment of the standard. Section 175A of the CAA requires
that a maintenance plan include such contingency measures as EPA deems
necessary to ensure 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 of the contingency measures,
and a time limit for action by the state. The state should also
identify specific indicators to be used to determine when the
contingency measures need to be adopted and implemented. The
maintenance plan must include a requirement that the state will
implement all measures with respect to control of the pollutant(s) that
were contained in the SIP before redesignation of the area to
attainment. See section 175A(d) of the CAA.
    As required by section 175A of the CAA, Ohio has adopted a
contingency plan for the Columbus area to address possible future
violations of the 1997 annual PM2.5 standard in this area.
Under Ohio's plan, if a violation of the 1997 annual PM2.5
standard occurs in the Columbus area or if a two-year average of the
weighted annual mean

PM2.5 concentration at any monitoring site in the area
equals or exceeds 15.0 [mu]g/m\3\, Ohio will implement an ``Action
Level Response'' to conduct an analysis to determine if the
unacceptable PM2.5 concentration is due to an exceptional
event, malfunction, or noncompliance with a source permit condition or
a rule requirement. If the air quality problem is found to not be due
to one of these situations, OEPA and the local metropolitan planning
organization or regional council of government will determine the
additional emission control measures needed to assure attainment of the
1997 annual PM2.5 standard. Ohio's candidate contingency
control measures include, but are not limited to, the following:
     Diesel emission control strategies;
     Alternative fuel requirements, such as liquid propane and
compressed natural gas, and diesel retrofit programs for fleet vehicle
operations;
     Tighter PM2.5, SO2, and primary
PM2.5 emissions offsets for new and modified major sources;
     Controls on impact crushers located at recycle scrap yards
using wet suppression;
     Upgrade of wet suppression requirements at concrete
manufacturing facilities; and
     Additional NOX RACT requirements statewide.

Emission control measures that can be implemented in a short time will
be selected and will be in place within 18 months after the close of
the calendar year that prompted the action level response. Ohio will
also consider the timing of the action level trigger and determine if
additional, significant new emission control regulations, not currently
included as part of the maintenance plan, will be implemented in a
timely manner and will negate the need for additional contingency
measures. OEPA also notes that the following NOX,
SO2, and primary PM2.5 source types are
potentially subject to additional emission control requirements: (1)
Industrial, Commercial, Institutional (ICI) boilers; (2) EGUs; (3)
process heaters; (4) internal combustion engines; (5) combustion
turbines; (6) sources with emissions exceeding 100 TPY; (7) fleet
vehicles; (8) concrete manufacturers; and, (9) aggregate processing
plants.
    OEPA commits to implement a ``Warning Level Response'' if any
monitor records a weighted annual average PM2.5
concentration of 15.0 [mu]g/m\3\ or greater in a single calendar year.
This trigger will result in a study to determine whether this
PM2.5 concentration indicates a trend toward higher
PM2.5 concentrations or whether emissions are increasing,
threatening to cause future violations of the 1997 annual
PM2.5 standard. If a worsening PM2.5
concentration trend is expected or if a future violation of the 1997
annual PM2.5 standard is projected to occur, the control
measures needed to reverse the trend will be selected and implemented,
taking into consideration the economic and social impacts of the
controls and the ease and timing of implementation. Implementation of
the controls will take place no later than 12 months after the calendar
year in which they are selected and adopted.
    EPA believes that Ohio's contingency plan satisfies the pertinent
requirements of section 175A of the CAA.
7. Provision for Future Update of the Annual PM2.5
Maintenance Plan
    As required by section 175A(b) of the CAA, Ohio commits to submit
to EPA an updated maintenance plan eight years after EPA redesignates
the Columbus area to attainment of the 1997 annual standard to cover an
additional 10-year period beyond the initial 10-year maintenance
period. As required by section 175A of the CAA, Ohio has also committed
to retain and implement the emission control measures contained in the
SIP prior to redesignation. If changes are needed in the SIP control
measures, Ohio commits to submit these changes to EPA as requested SIP
revisions.
    Finally, the state affirms that Ohio has the legal authority to
implement and enforce the requirements of the maintenance plan SIP
revision and commits to continue the enforcement of all regulations
that relate to the emission of all PM2.5 precursors in the
Columbus area.

E. Has Ohio adopted acceptable MVEBs for the PM2.5 maintenance period?

1. How are MVEBs developed and what are the MVEBs for the Columbus
area?
    Under section 176(c) of the CAA, transportation plans and
Transportation Improvement Programs (TIPs) must be evaluated for
conformity with SIPs. Consequently, Ohio's PM2.5
redesignation request and maintenance plan provide MVEBs, conformance
with which will assure that motor vehicle emissions are at or below