[Federal Register Volume 78, Number 152 (Wednesday, August 7, 2013)]
[Proposed Rules]
[Pages 48103-48123]
[FR Doc No: 2013-18948]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R05-OAR-2010-0899; FRL-9842-3]

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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to grant a redesignation request and State
Implementation Plan (SIP) revision request submitted by the state of
Illinois on October 15, 2010, and supplemented on September 16, 2011,
and May 6, 2013. The Illinois Environmental Protection Agency (IEPA)
requested EPA to redesignate the Illinois portion of the Chicago-Gary-
Lake County, Illinois-Indiana (IL-IN) nonattainment area to attainment
of the 1997 annual fine particulate matter (PM2.5) National
Ambient Air Quality Standard (NAAQS or standard) and requested EPA
approval of Illinois' PM2.5 maintenance plan and
PM2.5-related emission inventories for this area as
revisions of the Illinois SIP. The Illinois portion (Chicago area) of
this nonattainment area is: Cook, DuPage, Kane, Lake, McHenry, and Will
Counties, Aux Sable and Goose Lake Townships in Grundy County, and
Oswego Township in Kendall County. EPA is proposing to grant the
state's redesignation request and to approve the requested Illinois SIP
revisions, including the state's plan for maintaining attainment of the
1997 annual PM2.5 NAAQS in this area through 2025. EPA is
also proposing to approve Illinois' 2008 and 2025 Nitrogen Oxides
(NOX) and PM2.5 Motor Vehicle Emission Budgets
(MVEBs) for the Chicago area. Finally, EPA is proposing to approve
Illinois' 2002 NOX, Sulfur Dioxide (SO2),
Volatile Organic Compound, ammonia, and primary PM2.5
emission inventories for this area. In the context of this proposal to
redesignate the Chicago 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
PM2.5 standard.

DATES: Comments must be received on or before September 6, 2013.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2010-0899, 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, Chief, 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-
2010-0899. 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 area achieved attainment of the 1997 annual
PM2.5 standard?
    B. Has the Chicago area and the State of Illinois met all
applicable requirements of section 110 and part D of the Clean Air
Act, and does the Chicago area have a fully approved SIP under
section 110(k) of the Clean Air Act for purposes of redesignation to
attainment?
    1. Illinois Has Met All Applicable Requirements for Purposes of
Redesignation of the Chicago Area Under Section 110 and Part D of
the Clean Air Act
    a. Section 110 General SIP Requirements
    b. Part D Requirements
    2. The Chicago 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 Illinois' Redesignation Request
    iii. Subpart 4 and Control of PM2.5 Precursors
    C. Are the air quality improvements in the Chicago-Gary-Lake
County, IL-IN area due to permanent and enforceable emission
reductions?
    1. Permanent and Enforceable 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 Statewide in Illinois and in Upwind Areas
    i. NOX SIP Call
    ii. Clean Air Interstate Rule (CAIR) and Cross-State Air
Pollution Rule (CSAPR)
    c. Consent Decrees
    2. Emission Reductions
    a. Illinois' Demonstration That Significant Emission Reductions
Have Occurred in the Chicago-Gary-Lake County, IL-IN Area and in
Upwind Areas
    b. VOC and Ammonia Emission Reductions
    c. Conclusions Regarding Emission Reductions Between 2002 and
2005 in the Chicago Area
    D. Does Illinois have a fully approvable PM2.5
maintenance plan pursuant to section 175A of the CAA for the Chicago
area?
    1. What is required in a maintenance plan?
    2. Attainment Inventory
    3. Demonstration of Maintenance
    4. Monitoring Network
    5. Verification of Continued Attainment
    6. Contingency Plan
    7. Provision for Future Update of the Annual PM2.5
Maintenance Plan
    8. CAIR and CSAPR
    a. Background--Effect of the August 21, 2012, D.C. Circuit
Decision Regarding EPA's CSAPR
    b. Maintenance Plan Precursor Evaluation Resulting From Court
Decisions
    E. Has Illinois adopted acceptable MVEBs for the
PM2.5 maintenance period?
    1. How are MVEBs developed and what are the MVEBs for the
Chicago area?
    2. What are safety margins?
    F. Are the 2002 base year PM2.5-related emissions
inventories for the Chicago area approvable under section 172(c)(3)
of the CAA?
    1. EPA's Base Year Emissions Inventory SIP Policy
    2. 2002 Base Year PM2.5-Related Emission Inventories
for the Chicago 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 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 Chicago area to attainment of the 1997 annual
PM2.5 NAAQS. EPA is proposing to determine that the Chicago-
Gary-Lake County, IL-IN area has attained the 1997 annual
PM2.5 NAAQS based on quality assured, certified 2007-2012
air quality data. EPA is proposing to grant the redesignation of the
Chicago area to attainment of the 1997 annual PM2.5 NAAQS.
    EPA proposes to find that Illinois' PM2.5 maintenance
plan meets the requirements of section 175A of the Clean Air Act (CAA)
and is proposing to approve Illinois' PM2.5 maintenance plan
for the 1997 annual PM2.5 NAAQS for the Chicago area as a
revision to the Illinois SIP. The PM2.5 maintenance plan
provides for the maintenance of the 1997 annual PM2.5 NAAQS
in the Chicago-Gary-Lake County, IL-IN area through 2025. The state of
Illinois has committed to revising this maintenance plan to cover an
additional 10 years within eight years after EPA approves the
redesignation of the Chicago area to attainment of the 1997 annual
PM2.5 NAAQS.
    EPA is proposing to approve Illinois' 2008 and 2025 primary
PM2.5 (fine

particulates directly emitted by on-road motor vehicles) and
NOX MVEBs for the Chicago 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 Illinois' 2002 primary
PM2.5, NOX, SO2, Volatile Organic
Compound (VOC), and ammonia emission inventories for the Chicago area
as satisfying the requirement of section 172(c)(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
(primary PM2.5) or formed secondarily through chemical
reactions in the atmosphere involving precursor pollutants \1\ 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 Nitrogen Oxide (NO) and Nitrogen Dioxide
(NO2)) from power plants, mobile sources, and other
combustion sources.
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    \1\ Generally NOX, SO2, VOC, ammonia
(NH3), and primary PM2.5.
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    EPA promulgated the first air quality standards for
PM2.5 on July 18, 1997, at 62 FR 38652. In this rulemaking,
EPA promulgated an annual standard at a level of 15 micrograms per
cubic meter ([micro]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 [micro]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 Chicago-Gary-Lake County, IL-IN area as nonattainment
for the 1997 annual PM2.5 standard. This area includes the
Chicago area in Illinois and Lake and Porter Counties in Indiana.
    On October 17, 2006, at 71 FR 61144, EPA retained the annual
PM2.5 standard at 15 [micro]g/m\3\ (2006 annual
PM2.5 standard), but revised the 24-hour PM2.5
standard to 35 [micro]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).
Since the Chicago area is designated as nonattainment for the 1997
annual PM2.5 standard, today's proposed action addresses
redesignation of this area only for the 1997 annual PM2.5
standard.
    On November 27, 2009, EPA made a final determination that the
Chicago area had attained the 1997 annual PM2.5 standard (76
FR 62243). 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 the Chicago-Gary-Lake County, IL-IN area for the period of 2006-
2008. Based on our review of complete, quality-assured, and state-
certified ambient PM2.5 monitoring data from 2009-2012 in
the Chicago-Gary-Lake County, IL-IN area, we are proposing to determine
that the Chicago area continues to attain the 1997 annual
PM2.5 NAAQS.
    On October 15, 2010, IEPA submitted a request to EPA for the
redesignation of the Chicago area to attainment of the 1997 annual
PM2.5 NAAQS and for EPA approval of a SIP revision
containing emission inventories and a maintenance plan for the area.
The maintenance plan also includes 2008 and 2025 MVEBs for the Chicago
area. In a supplemental submission to EPA on September 16, 2011, the
IEPA revised the on-road mobile source emissions and MVEBs in the
original submittal to reflect the use of EPA's MOVES model to calculate
mobile source emissions. In a supplemental submission to EPA on May 6,
2013, the IEPA submitted VOC and ammonia emission inventories to
supplement the emission inventories that had previously been submitted
to explain the attainment of the 1997 annual PM2.5 standard
in the Chicago-Gary-Lake County, IL-IN area and to demonstrate future
maintenance of the PM2.5 standard in this area.
    In this proposed redesignation, 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 EME Homer City Generation,
L.P. v. EPA, 696 F.3d 7 (D.C. Cir. 2012), which vacated and remanded
Cross-State Air Pollution Rule (CSAPR) and ordered EPA to continue
administering the Clean Air Interstate Rule (CAIR) ``pending . . .
development of a valid replacement.'' EME Homer City at 38. The D.C.
Circuit denied all petitions for rehearing on January 24, 2013.\2\ 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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    \2\ 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 petition is not a decision on the merits but instead a
decision to review the case on its 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 area achieved attainment of the 1997 annual PM2.5
standard?

    In a final rulemaking dated November 27, 2009, at 76 FR 62243, EPA
determined that the Chicago-Gary-Lake County, IL-IN area had attained
the 1997 annual PM2.5 standard. This determination was based
on complete, quality-assured monitoring data in this area for the
calendar years of 2006-2008.
    In its September 16, 2011, redesignation request, Illinois presents

quality-assured, state-certified PM2.5 data for the period
of 2007-2009. These data show that the Chicago-Gary-Lake County, IL-IN
area attained the 1997 annual PM2.5 standard through 2009.
    We have also obtained quality-assured and state-certified data for
the states of Illinois and Indiana for 2010, 2011, and 2012. Data
recorded in EPA's AQS show that the Chicago-Gary-Lake County, IL-IN
area initially attained the 1997 annual PM2.5 standard
beginning in 2005-2007, and this area has continued to attain this
standard through 2012.\3\
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    \3\ Preliminary data for 2012 show that the Chicago-Gary-Lake
County, IL-IN area continues to attain the 1997 annual
PM2.5 standard through 2012.
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    Table 1 provides a summary of the PM2.5 annual air
quality data for the Chicago-Gary-Lake County, IL-IN area for the
period of 2007-2012. These data have been quality-assured and certified
by the states of Illinois and Indiana.

                      Table 1--PM2.5 Annual Average Concentrations for the Chicago-Gary-Lake County, IL-IN PM2.5 Nonattainment Area
                                                                     (In [mu]g/m\3\)
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            County                   Monitoring site           2007            2008            2009            2010            2011            2012
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                                                                Illinois Monitoring Sites
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Cook..........................  Blue Island.............            14.3            12.5            11.7            11.6            11.6            10.9
Cook..........................  Chicago--Commonwealth               14.3            11.9            11.1            12.3            11.3            11.3
                                 Edison.
Cook..........................  Chicago--Springfield....            15.2            12.0            11.3        12.0 (2)        11.5 (2)            11.9
Cook..........................  Chicago--Mayfair........            15.5            12.2            12.7            12.6            11.8            11.6
Cook..........................  Chicago--SE Police......            14.1            11.8            11.0            12.5             N/A             N/A
Cook..........................  Chicago--Washington.....            15.7            12.5            11.6            14.0            12.6            11.5
Cook..........................  Cicero..................            14.8        13.3 (2)        12.8 (2)            11.9            11.4            10.4
Cook..........................  Des Plaines.............            12.7            11.4            11.0            10.6            10.6            10.9
Cook..........................  McCook (1)..............            15.6            12.9            12.6            12.6            12.6            12.6
Cook..........................  Northbrook..............            13.2            10.1             9.3             9.3            10.2            10.2
Cook..........................  Schiller Park (1).......            15.4        13.6 (2)            12.9            12.6            13.3            13.1
Cook..........................  Summit..................            14.8            12.0            11.6            12.2            11.0            11.3
DuPage........................  Naperville..............            13.8            11.3             9.8            11.7            10.5            10.1
Kane..........................  Aurora..................            13.2            10.3            10.0            11.3             9.8            10.0
Kane..........................  Elgin...................            14.5            10.8             9.8            11.4            10.8             9.9
Lake..........................  Zion....................            11.9             9.3             8.8             9.7             N/A             N/A
McHenry.......................  Cary....................            11.6            10.1             9.6            10.2            10.1            10.1
Will..........................  Braidwood...............        12.1 (2)            10.3             8.7            10.0            10.4             9.3
Will..........................  Joliet..................            14.6            11.7            10.5            11.8            10.2            11.1
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                                                                Indiana Monitoring Sites
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Lake..........................  Franklin School.........            14.4            12.0            11.3            12.5            11.4            10.7
Lake..........................  Griffith................            13.2            11.7            11.0            12.4            11.2             N/A
Lake..........................  Madison Street..........            14.6            12.3            12.1            12.9            12.1            11.5
Lake..........................  Hammond--Purdue.........            13.8            11.7            15.9            12.3            11.4            10.6
Lake..........................  Clark High School.......            13.7            12.4            10.8            11.9            10.7            10.5
Porter........................  Ogden Dunes.............            13.8            10.9            11.3            11.6            10.6             9.9
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    Notes: (1) Annual standard for PM2.5 does not apply
to these sites due to their proximity to industrial or roadway
sources and lack of representation of general population exposure;
and (2) the data for these sites and years do not meet data
completeness requirements (see a discussion of this issue below).

    Table 2 gives the three-year averages of the annual
PM2.5 concentrations for 2007-2009, 2008-2010, 2009-2011,
and 2010-2012 for each of the PM2.5 monitoring sites in the
Chicago-Gary-Lake County, IL-IN PM2.5 nonattainment area.

Table 2--Three-Year Averages of Annual Average PM2.5 Concentrations in the Chicago-Gary-Lake County, IL-IN PM2.5
                                               Nonattainment Area
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          County               Monitoring site       2007-2009       2008-2010       2009-2011       2010-2012
----------------------------------------------------------------------------------------------------------------
                                            Illinois Monitoring Sites
----------------------------------------------------------------------------------------------------------------
Cook......................  Blue Island.........            12.8            11.9            11.6            11.4
Cook......................  Chicago--Commonwealt            12.4            11.8            11.6            11.6
                             h Edison.
Cook......................  Chicago--Springfield            12.8            11.8            11.6            11.6
Cook......................  Chicago--Mayfair....            13.5            12.5            12.4            12.0
Cook......................  Chicago--SE Police..            12.3            11.8             N/A             N/A
Cook......................  Chicago--Washington.            13.3            12.7            12.7            12.7
Cook......................  Cicero..............            13.1            12.7            12.0            11.2
Cook......................  Des Plaines.........            11.7            11.0            10.7            10.7

Cook......................  McCook..............            13.7            12.7            12.6            12.6
Cook......................  Northbrook..........            10.9             9.6             9.6             9.9
Cook......................  Schiller Park.......            14.0            13.0            12.9            13.0
Cook......................  Summit..............            12.8            11.9            11.6            11.5
DuPage....................  Naperville..........            11.6            10.9            10.7            10.8
Kane......................  Aurora..............            11.2            10.5            10.4            10.4
Kane......................  Elgin...............            11.6            10.7            10.7            10.7
Lake......................  Zion................            10.0             9.3             N/A             N/A
McHenry...................  Cary................            10.4            10.0            10.0            10.1
Will......................  Braidwood...........            10.4             9.7             9.7             9.9
Will......................  Joliet..............            10.2            11.3            10.8            11.0
----------------------------------------------------------------------------------------------------------------
                                            Indiana Monitoring Sites
----------------------------------------------------------------------------------------------------------------
Lake......................  Franklin School.....            11.4            11.9            11.7            11.5
Lake......................  Griffith............            11.2            11.7            11.5             N/A
Lake......................  Madison Street......            12.1            12.4            12.4            12.2
Lake......................  Hammond--Purdue.....            11.4            13.3            13.2            11.4
Lake......................  Clark High School...            10.7            11.7            11.1            11.0
Porter....................  Ogden Dunes.........            10.6            11.3            11.2            10.7
----------------------------------------------------------------------------------------------------------------

    The data in tables 1 and 2 show that all PM2.5 monitors
in the Chicago-Gary-Lake County, IL-IN area have recorded
PM2.5 concentrations attaining the 1997 annual
PM2.5 standard during the most recent three years of
quality-assured, state-certified of PM2.5 data collection.
As noted above, however, the PM2.5 data for several sites in
table 1 need further discussion.
    First, under 40 CFR 58.30(a)(1), for monitoring sites with data
that are representative of relatively unique, generally localized
concentrations, the data are compared only to the 24-hour
PM2.5 NAAQS, and not to the annual PM2.5 NAAQS.
Illinois has two sites, McCook and Schiller Park, that the IEPA
believes are not representative of exposure for the general populace
due to the proximity of these sites to localized industrial or roadway
sources. EPA is not judging whether this designation is appropriate.
The applicable regulation, at 40 CFR 58.30(a)(2), recognizes that some
microscale sites collect data that are representative of multiple
locations with localized high concentrations, and provides in these
cases that the data are appropriate for comparison to the annual
PM2.5 standard. The Schiller Park site is near a major
highway, and the site may be representative of multiple locations in
the Chicago area that have similar proximity to major highways. For
this reason, Table 1 above includes annual mean PM2.5
concentrations for this site. In any case, this site shows annual mean
PM2.5 concentrations that meet the 1997 annual
PM2.5 standard.
    With regard to the McCook monitoring site, we agree with the IEPA
that this is a monitoring site that is located near a localized
industrial source and produces PM2.5 concentrations that are
not generally representative of exposure for the general populace on a
long-term basis. As such, in keeping with 40 CFR 58.30(a)(1), the
annual mean PM2.5 concentrations at this site should not be
compared to the 1997 annual PM2.5 standard when judging the
attainment status of the Chicago-Gary-Lake County, IL-IN area. In any
case, this site also shows annual mean PM2.5 concentrations
that meet the 1997 annual PM2.5 standard.
    EPA concludes that no violation of the 1997 annual PM2.5
standard has been recorded in the Chicago-Gary-Lake County, IL-IN area
for any three-year period during 2007-2012. For the reasons discussed
above, EPA proposes to determine that the Chicago-Gary-Lake County, IL-
IN area has attained the 1997 annual PM2.5 standard.
    Illinois commits to continue monitoring PM2.5 in the
Chicago area according to an EPA-approved monitoring plan, as required
to confirm and assure maintenance of the 1997 annual PM2.5
standard in this area. If changes in the PM2.5 monitoring
system become necessary, IEPA will work with EPA to ensure the
continued adequacy of the monitoring system. Illinois will continue to
quality-assure the monitoring data to meet the requirements of 40 CFR
part 58.

B. Has the Chicago area and the State of Illinois met all applicable
requirements of section 110 and part D of the Clean Air Act, and does
the Chicago area have a fully approved SIP under section 110(k) of the
Clean Air Act for purposes of redesignation to attainment?

    We are proposing to find that Illinois has met all currently
applicable SIP requirements for the purposes of redesignation of the
Chicago area under section 110 of the CAA (general SIP requirements).
We are also proposing to find that the Illinois 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) of the CAA. We are proposing to find that all
applicable requirements of the Illinois SIP, for purposes of
redesignation, have been implemented, in accordance with section
107(d)(3)(E)(ii) of the CAA. As discussed below, in this section, EPA
is proposing to approve Illinois' 2002 NOX, SO2,
and PM2.5 emissions inventory and 2007 VOC and ammonia
emissions inventory as meeting the section 172(C)(3) requirement for a
comprehensive emissions inventory.
    In making these proposed determinations, we have ascertained which
SIP requirements are applicable for purposes of redesignation, and have
concluded that there are SIP measures meeting these requirements and
that they are approved or will be approved by the time of final
rulemaking on the State's PM2.5 redesignation request.

1. Illinois Has Met All Applicable Requirements for Purposes of
Redesignation of the Chicago Area Under Section 110 and Part D of the
Clean Air Act
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 any
stationary source within the 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 SIPs contain measures
to prevent sources in a state from significantly contributing to air
quality problems in another state. However, the section 110(a)(2)(D)
SIP requirements are not linked with a particular area's designation
and classification. EPA believes that the requirements linked with an
area's designation and classification are the relevant measures to
evaluate in reviewing a redesignation request. The section 110(a)(2)(D)
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 are not applicable requirements for
purposes of redesignation.
    Further, we believe that section 110(a)(2) elements other than
those described above that are not connected with nonattainment plan
submissions and that are not linked with an area's attainment status
are also not applicable requirements for purposes of redesignation. A
state remains subject to these requirements regardless of an area's
designation and after the area is redesignated to attainment. We
conclude that only the section 110 and part D requirements that are
linked with an area's designation and classification are the relevant
measures which we must consider in evaluating a redesignation request.
This approach is consistent with EPA's 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-Lorain, Ohio, final rulemaking (61 FR 20458, May 7, 1996); and
Tampa, Florida, final rulemaking (60 FR 62748, December 7, 1995). See
also the discussion of this issue in the Cincinnati, Ohio 1-hour ozone
redesignation (65 FR 3780, June 19, 2000), and in the Pittsburgh,
Pennsylvania 1-hour ozone redesignation (66 FR 50399, October 19,
2001).
    We have reviewed the Illinois SIP and have concluded that it meets
the general SIP requirements under section 110 of the CAA to the extent
they are applicable to the state's request for redesignation. EPA has
previously approved provisions of the Illinois SIP addressing section
110 requirements, including provisions addressing particulate matter,
at 40 CFR 52.720. In a submittal dated December 12, 2007, Illinois
addressed infrastructure SIP elements required under section 110(a)(2)
of the CAA for PM2.5 under the 1997 annual PM2.5
standard. EPA approved this submittal on August 12, 2011, at 76 FR
41075. The requirements of section 110(a)(2), however, are statewide
SIP requirements that are not linked to the PM2.5
nonattainment status of the Chicago area. Therefore, EPA believes that
these infrastructure elements are not applicable requirements for
purposes of review of the state's PM2.5 redesignation
request.
b. Part D Requirements
    EPA has determined that, if EPA approves the base year emissions
inventories, discussed in section V.F below, the Illinois SIP will meet
the SIP requirements applicable for purposes of redesignation under
part D of the CAA for the Chicago area.
    Subpart 1 of part D, found in sections 172-176 of the CAA, sets
forth the basic nonattainment requirements applicable for nonattainment
areas.
Subpart 1 Section 172 Requirements
    The applicable subpart 1 requirements are contained in sections
172(c)(1)-(9) of the CAA. A thorough discussion of the requirements
contained in section 172 can be found in the General Preamble for
Implementation of title I (57 FR 13498, April 16, 1992).
    Section 172(c)(1) requires the state plans for all nonattainment
areas to provide for the implementation of Reasonably Available Control
Measures (RACM) as expeditiously as practicable. EPA interprets this
requirement to impose a duty on all states with nonattainment areas to
consider all available control measures and to adopt and implement such
measures as are reasonably available for implementation in these areas
as components of the areas' attainment demonstrations (the attainment
demonstrations must address RACM). Because attainment of the 1997
annual PM2.5 NAAQS has been achieved in the Chicago-Gary-
Lake County, IL-IN area, no additional RACM measures are needed to
provide for attainment, and the section 172(c)(1) requirements are no
longer considered to be applicable as a prerequisite for approval of
Illinois' redesignation request, provided the area continues to attain
the standard until the redesignation of the Chicago area occurs. See 40
CFR 51.1004(c).
    Section 172(c)(2) requires plans for all nonattainment areas to
provide for reasonable further progress (RFP) toward attainment of the
NAAQS. This requirement is not relevant for purposes of redesignation
because the Chicago-Gary-Lake County, IL-IN area has monitored
attainment of the 1997 annual PM2.5 NAAQS (General Preamble,
57 FR 13564). See also 40 CFR 51.1009. In addition, because the
Chicago-Gary-Lake County, IL-IN area has attained the 1997 annual
PM2.5 NAAQS, the requirement for RFP under section
172(c)(2), as well as the requirement for contingency measures under
section 172(c)(9), is not applicable for purposes of redesignation. Id.
    Section 172(c)(3) requires submission and EPA approval of a
comprehensive, accurate and current inventory of actual emissions.
Illinois submitted a 2002 base year emissions inventory for primary
PM2.5, NOX, and SO2 in June 2006, and
documented this emissions inventory in a June 2006 publication titled
``Illinois Base Year Particulate Matter and Haze Inventory for 2002''.
As discussed below in section V.F, EPA is proposing to approve
Illinois' 2002 base year emission inventories as meeting the section
172(c)(3) emission inventory requirement for the Chicago area.
    Section 172(c)(4) requires the identification and quantification of
emissions for major new and modified

stationary sources to be allowed in an area, and section 172(c)(5)
requires source permits for the construction and operation of new and
modified major stationary sources in the nonattainment area. EPA
approved Illinois NSR program \4\ on December 17, 1992 (57 FR 59928),
September 27, 1995 (60 FR 49780), and May 13, 2003 (68 FR 25504).
Further, EPA has determined that, since PSD requirements \5\ will apply
after redesignation, the Chicago area and the state of Illinois need
not comply with the requirement that a NSR program be approved prior to
redesignation, provided that the state demonstrates maintenance of the
NAAQS without implementation of part D NSR. A more detailed rationale
for this view is described in a memorandum from Mary Nichols, Assistant
Administrator for Air and Radiation, dated October 14, 1994, titled,
``Part D New Source Review Requirements for Areas Requesting
Redesignation to Attainment'' (Nichols memorandum). Illinois has
demonstrated that the Chicago-Gary-Lake County, IL-IN area will be able
to maintain the 1997 annual PM2.5 standard without the
continued implementation of the state's part D NSR program. Therefore,
EPA concludes that Illinois need not have a fully approved part D NSR
program as an applicable requirement for approval of the state's
redesignation request. The state's PSD program will become effective in
the Chicago area upon redesignation to attainment of the 1997
PM2.5 standard. See redesignation 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).
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    \4\ The NSR program controls the growth and permitting of major
source emissions in nonattainment areas.
    \5\ PSD requirements control the growth of new source emissions
in areas designated as attainment for a NAAQS.
---------------------------------------------------------------------------

    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 in the Chicago area, no additional measures
are needed to provide for attainment of the standard.
    Section 172(c)(7) requires the SIP to meet the applicable
provisions of section 110(a)(2). As noted above, in section V.B.1.a, we
conclude that the Illinois SIP meets the requirements of section
110(a)(2) applicable for purposes of redesignation.
Subpart 1 Section 176(c)(4)(D) Conformity SIP Requirements
    Section 176(c) of the CAA requires states to establish criteria and
procedures to ensure that Federally-supported or funded activities
including highway projects, conform to the air quality planning goals
of the SIPs. 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). State conformity SIP
revisions must be consistent with Federal conformity regulations
relating to consultation, enforcement and enforceability, which EPA
promulgated pursuant to CAA requirements.
    EPA believes that it is reasonable to interpret the conformity SIP
requirements as not applying for purposes of evaluating the
redesignation request under section 107(d) for two reasons. First, the
requirement to submit SIP revisions to comply with the 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 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).
    EPA approved Illinois' general conformity SIP on December 23, 1997
(62 FR 67000). Illinois does not have a Federally-approved
transportation conformity SIP. However, Illinois performs conformity
analyses pursuant to EPA's Federal conformity rules. Illinois has
submitted on-road mobile source emission budgets for the Chicago area
of 5,100 tons per year (TPY) of primary PM2.5 and 127,951
TPY of NOX for 2008 and 2,377 TPY of primary
PM2.5 and 44,224 TPY of NOX for 2025,
respectively. Illinois must use these MVEBs in any conformity
determination that is effective on or after the effective date of the
PM2.5 maintenance plan approval and effective date of EPA's
approval of the redesignation of the Chicago area to attainment of the
1997 annual PM2.5 standard.
2. The Chicago Area Has a Fully Approved Applicable SIP Under Section
110(k) of the CAA
    Upon final approval of Illinois's comprehensive 2002 emissions
inventories, EPA will have fully approved the Illinois SIP for the
Chicago 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 when
rulemaking on a redesignation request (See page 3 of the September 4,
1992, John Calcagni memorandum titled ``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, Illinois has adopted and
submitted, and EPA has fully approved, SIP provisions addressing
various required SIP elements under the particulate matter standards.
In this action, EPA is proposing to approve Illinois's 2002 base year
emissions inventories for the Chicago area as meeting the requirement
of section 172(c)(3) of the CAA for the 1997 annual PM2.5
standard.
3. Nonattainment Requirements
    No Illinois SIP provision applicable for redesignation of the
Chicago area is currently disapproved, conditionally approved or
partially approved.
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 redesignation proposed rule, 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 Chicago 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 Illinois' 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
Chicago 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 Illinois' redesignation request for the Chicago 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 Chicago 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
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'').\6\ In
this case, at the time that Illinois submitted its redesignation
request, requirements under subpart 4 were not due, and indeed, were
not yet known to apply.
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    \6\ 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 Chicago 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 the provisions of 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 Act for this purpose.
    Second, a fundamental premise for redesignating a nonattainment
area to attainment is that the area has attained the relevant NAAQS due
to emission reductions from existing controls. Thus, an area, for which
a redesignation request has been submitted, would have already attained
the NAAQS as a result of satisfying statutory requirements that came
due prior to the submission of the request. Absent a showing that
unadopted and unimplemented requirements are necessary for future
maintenance, it is reasonable to view the requirements applicable for
purposes of evaluating the redesignation request as including only
those SIP requirements that have already come due. These are the
requirements that led to attainment of the NAAQS. To require,

for redesignation approval, that a state also satisfy additional SIP
requirements coming due after the state submits its complete
redesignation request, and while EPA is reviewing it, would compel the
state to do more than is necessary to attain the NAAQS, without a
showing that the additional requirements are necessary for maintenance.
    In the context of this redesignation, the timing and nature of the
Court's January 4, 2013, decision in NRDC v. EPA compound the
consequences of imposing requirements that come due after the
redesignation request is submitted. The state submitted its
redesignation request on October 15, 2010, 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),\7\ 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
Illinois 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.
---------------------------------------------------------------------------

    \7\ 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).
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ii. Subpart 4 Requirements and Illinois' 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
Chicago area still qualifies for redesignation to attainment. As
explained below, EPA believes that the redesignation request for the
Chicago 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 Chicago area, EPA notes
that subpart 4 incorporates components of subpart 1 of part D, which
contain 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 \8\
nonattainment areas, and under the Court's January 4, 2013, decision in
NRDC v. EPA, these same statutory requirements also apply for
PM2.5 nonattainment areas. EPA has longstanding general
guidance that interprets the 1990 amendments to the CAA, making
recommendations to states for meeting the statutory requirements for
SIPs for nonattainment areas. See, ``State Implementation Plans;
General Preamble for the Implementation of Title I of the Clear Air Act
Amendments of 1990,'' 57 FR 13498 (April 16, 1992) (the ``General
Preamble''). 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.
---------------------------------------------------------------------------

    \8\ 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 Chicago area to be a ``moderate'' PM2.5
nonattainment area. Under section 188 of the CAA, all areas designated
as nonattainment areas under subpart 4 would initially be classified by
operation of law as ``moderate'' nonattainment areas, and would remain
as 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.\9\ 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).
---------------------------------------------------------------------------

    \9\ 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,\10\ when EPA evaluates a redesignation request under either
subpart 1 and/or subpart 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:
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    \10\ 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 for the Interpretation of Title I of the Clean Air
Act Amendments of 1990''; (57 FR 13498, 13564, April 16, 1992). 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 \11\
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).
---------------------------------------------------------------------------

    \11\ 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 Chicago area is consistent with the Court's
decision on this aspect of subpart 4. First, while the Court, citing
section 189(e), stated that ``for a PM10 area governed by
subpart 4, a precursor is `presumptively regulated,''' the Court
expressly declined to decide the specific challenge to EPA's 1997
PM2.5 implementation rule provisions regarding ammonia and
VOC as precursors. The Court had no occasion to 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 Chicago
area, EPA believes that doing so is consistent with proposing
redesignation of the area for the 1997 PM2.5 standard. The
Chicago 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.\12\ 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 major
stationary sources 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.
---------------------------------------------------------------------------

    \12\ Under either subpart 1 or subpart 4, for purposes of
demonstrating attainment as expeditiously as practicable, a state is
required to evaluate all economically and technologically feasible
control measures for direct PM emissions and precursor emissions,
and adopt those measures that are deemed reasonably available.
---------------------------------------------------------------------------

    In the General Preamble, EPA discusses its approach to implementing
section 189(e). See 57 FR 13538-13542. 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).
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 supplemental determination is based on
our findings that: (1) The Chicago 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.\13\ In the alternative, EPA proposes to determine
that, under the express exception provisions of section 189(e), and in
the context of the redesignation of the area, which is attaining the
1997 annual PM2.5 standard, at present ammonia and VOC
precursors from major stationary sources do not contribute
significantly to levels exceeding the 1997 PM2.5 standard in
this area. See 57 FR 13539-13542.
---------------------------------------------------------------------------

    \13\ The Chicago 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 in and of themselves do not require
additional controls of these precursors for an area that already
qualifies for redesignation. Nor does EPA believe that requiring
Illinois to address precursors differently than they have already would
result in a substantively different outcome.
    Although, as EPA has emphasized, its consideration here of
precursor requirements under subpart 4 is in the context of a
redesignation to attainment, EPA's existing interpretation of subpart 4
requirements with respect to precursors in attainment plans for
PM10 contemplates that states may develop attainment plans
that regulate only those precursors that are necessary for purposes of
attainment in the area in question, i.e., states may determine that
only certain precursors need be regulated for attainment and control
purposes.\14\ Courts have upheld this approach to the requirements of
subpart 4 for PM10.\15\ EPA believes that application of
this approach to PM2.5 precursors under subpart 4 is
reasonable. Because the Chicago 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 Illinois' request for redesignation of the
Chicago area. In the context of a redesignation, the area has shown
that it has attained the standard. Moreover, the state has shown and
EPA has proposed to determine that attainment in this area is due to
permanent and enforceable emissions reductions on all precursors
necessary to provide for continued attainment. It follows logically
that no further control of additional precursors is necessary.
Accordingly, EPA does not view the January 4, 2013, decision of the
Court as precluding redesignation of the Chicago area to attainment for
the 1997 PM2.5 NAAQS at this time.
---------------------------------------------------------------------------

    \14\ 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 did not impose controls on
SO2, VOC, or ammonia emissions).
    \15\ See, e.g., Assoc. of Irritated Residents v. EPA et al., 423
F.3d 989 (9th Cir. 2005).
---------------------------------------------------------------------------

    In sum, even if Illinois were required to address precursors for
the Chicago 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 air quality improvements in the Chicago-Gary-Lake County,
IL-IN Area due to permanent and enforceable emission reductions?

    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. EPA finds that Illinois has
demonstrated that the observed PM2.5 air quality improvement
in the Chicago-Gary-Lake County, IL-IN area is due to permanent and
enforceable emission reductions. In making this demonstration, Illinois
first determined and documented the change in primary PM2.5,
NOX, and SO2 emissions in the Chicago-Gary-Lake
County, IL-IN area between 2002 (a standard-violation year) and 2008
(an attainment year). Illinois demonstrated that the reduction in
emissions and the corresponding improvement in air quality over the
intervening period (2002-2008) can be attributed to a number of
regulatory control measures that have been implemented in the Chicago-
Gary-Lake County, IL-IN area and in surrounding contributing areas in
the recent years.

1. Permanent and Enforceable Controls
    The following is a discussion of the permanent and enforceable
measures that have been implemented in the Chicago area and in upwind
areas.
a. Federal Emission Control Measures
    Reductions in PM2.5 precursor emissions have occurred
statewide in Illinois and in upwind areas as a result of the following
Federal emission control measures, with additional emission reductions
expected in the future. Federal emission control measures include the
following.
i. Tier 2 Emission Standards for Vehicles and Gasoline Sulfur Standards
    40 CFR part 86, subpart S. 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 end of the phase-in period, the following
vehicle NOX emission reductions will occur nationwide:
passenger cars (light duty vehicles), 77 percent; light duty trucks,
minivans, and sports utility vehicles, 86 percent; and, larger sports
utility vehicles, vans, and heavier trucks, 69 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 2008-2010 attainment period; however,
additional emission reductions will continue to occur 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.
ii. Heavy-Duty Diesel Engine Rule
    EPA issued this rule on January 18, 2001 (66 FR 5002). This rule
went into effect in 2004 and includes standards limiting the sulfur
content of diesel fuel. A second phase 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,
compared to existing engines using higher sulfur content fuel. The
reductions in fuel sulfur content occurred by the 2008-2010 attainment
period. Some of the emissions reductions resulting from new vehicle
standards also occurred during the 2008-2010 attainment period;
however, additional emission reductions will continue to occur
throughout the maintenance period as the fleet of older heavy-duty
diesel engines turns over. This rule will also lower SO2
emissions from engines using the low sulfur diesel fuel, resulting in
lower PM2.5 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
    On June 29, 2004 (69 FR 38958), 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 are 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 limited non-road
diesel fuel content to 500 ppm starting in 2007, with a further
reduction to 15 ppm starting in 2010. The combined engine standards and
fuel sulfur content limits reduce 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 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 2008-2010
period; although most of the engine emission reductions will occur
during the maintenance period as the fleet of non-road diesel engines
turns over.
iv. Non-Road Spark-Ignition Engines and Recreational Engine Standards
    On November 8, 2002 67 FR 68243), 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 for large spark-ignition engines were
implemented in two tiers, with Tier I starting in 2004 and Tier 2
starting in 2007. Recreational vehicle emission standards were phased
in from 2004 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 in carbon monoxide (CO) emissions are expected by
2020. Some of these emission reductions 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 Statewide in Illinois and in Upwind Areas
    Due to the significance of sulfates and nitrates as components of
PM2.5 in the Chicago-Gary-Lake County, IL-IN area, the
PM2.5 air quality in this area is strongly affected by
regulation of SO2 and NOX emissions from power
plants in areas upwind of the Chicago-Gary-Lake County, IL-IN area. The
emission control regulations impacting the upwind area include the
following.
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 from Electric Generating Units (EGUs),
large industrial boilers, and cement kilns. Affected states were
required to comply with Phase I of the 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 are permanent and enforceable. The state of Illinois and other
nearby upwind states, including Michigan, Indiana, and Kentucky were
subject to the NOX SIP call.
ii. Clean Air Interstate Rule (CAIR) and Cross-State Air Pollution Rule
(CSAPR)
    EPA proposed CAIR on January 30, 2004, at 69 FR 4566, 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 promulgated CSAPR (76 FR 48208, August 8, 2011) to replace
CAIR. See 76 FR 59517. As noted above, CAIR requires 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 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, 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. On June 24, 2013,
the U.S. Supreme Court granted the petitions for certiorari.
Nonetheless, EPA intends to continue to act in accordance with the EME
Homer City opinion until the U.S. Supreme Court issues its decision.
    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 here proposing to determine
that these 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 Chicago-Gary-Lake County, IL-IN area, as discussed
below, for CAA section 175A).
c. Consent Decrees
    Two petroleum refineries, the CITGO and Exxon Mobil refineries,
have units subject to Best Available Retrofit Technology (BART)
requirements for purposes of achieving reduced haze levels: The CITGO
refinery in Lemont, Illinois and the Exxon Mobil refinery south of
Joliet, Illinois. Both refineries will be required to reduce emissions
by a Federal consent decree resolving an enforcement action brought by
EPA against a number of refineries. The consent decrees require the
CITGO and Exxon Mobil refineries (and other refineries in Illinois) to
operate controls at the Best Available Control Technology (BACT) level.
Illinois evaluated the subject-to-BART units at the CITGO and Exxon
Mobil refineries in the consent decree. It found that the
NOX and SO2 emission limits for these units
satisfy BART.
    A consent decree between the United States and CITGO Petroleum
Corporation was entered in the U.S. District Court for the Southern
District of Texas on October 6, 2004 (No. H-04-3883). The consent
decree requires the company to operate Selective Catalytic Reduction
(SCR) and a wet scrubbing system at its Fluid Catalytic Cracking Unit
(FCCU) that will reduce NOX emissions by more than 90
percent and SO2 emissions by 85 percent. The controls on the
FCCU are expected to result in a reduction of NOX emissions
from 1,065.7 to 106.6 TPY and SO2 emissions from 10,982.5 to
107.9 TPY by 2013. CITGO has also added a tail gas recovery unit that
reduces SO2 emissions from its sulfur train units from
4340.0 to 91.2 TPY, a 98 percent reduction. The emission controls on
all units at CITGO's Lemont refinery will reduce NOX
emissions by 1,268 TPY and SO2 emissions by 15,123 TPY.
    A consent decree between the United States and Exxon Mobil
Corporation was entered in the U.S. District Court for the Northern
District of Illinois on October 11, 2005 (No. O5-C-5809). The consent
decree for Exxon Mobil requires SCR operation on its FCCU in addition
to maintenance of the existing wet scrubbing system. The controls on
the FCCU result in a 1,636.2 TPY decrease in NOX emissions
from 1,818.0 to 181.8 TPY and a 9,667.7 TPY decrease in SO2
emissions from 9,865.0 to 197.3 TPY. Exxon Mobil has also added a tail
gas recovery unit on its south sulfur recovery unit. That unit reduces
SO2 emissions by 9,153.8 TPY to 186.8 TPY. The emission
controls at Exxon Mobil's Joliet refinery will reduce NOX
emissions by 1,695 TPY and SO2 emissions by 18,821 TPY.
    These two consent decrees are Federally enforceable and also
require that the refineries submit permit applications to Illinois to
incorporate the required emission limits into Federally enforceable air
permits (other than Title V). Therefore, emission limits established by
the consent decrees may be relied upon by Illinois for addressing the
BART requirement for these facilities and for crediting toward the
reduction of PM2.5 levels in the Chicago area and
maintenance of the 1997 annual PM2.5 standard in the
Chicago-Gary-Lake County, IL-IN area.
2. Emission Reductions
a. Illinois' Demonstration That Significant Emission Reductions Have
Occurred in the Chicago-Gary-Lake County, IL-IN Area and In Upwind
Areas
    To demonstrate that significant emission reductions have resulted
in attainment, Illinois compared the Chicago area NOX,
SO2, and primary PM2.5 emissions for 2002 with
those of 2008. As noted above, the 2008 emissions represent those for a
year in which the Chicago-Gary-Lake County, IL-IN area was attaining
the 1997 annual PM2.5 standard (2008 is the middle year of
the 2007-2009 period in which the Chicago-Gary-Lake County, IL-IN area
initially attained the 1997 annual PM2.5 standard), and 2002
represents a year in which the Chicago-Gary-Lake County, IL-IN area was
violating this standard.
    The derivation of the 2002 (base year) emissions is discussed in
more detail below in section V.F. 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 Illinois' 2008 Annual
Emissions Reports (AERs) submitted to the IEPA by individual source
facilities. Area source emissions were calculated using the most
recently available emission calculation methodologies, emission factors
developed by EPA, and activity data (population, employment, fuel use,
etc.) specific to 2008. On-road mobile source emissions were calculated
using EPA's MOVES emissions model with 2008 Vehicle Miles Traveled
(VMT) data provided by the Illinois Department of Transportation
(IDOT). Off-road mobile source emissions were calculated using either
EPA's NONROAD emission model (for all non-road sources except
commercial marine vessels, locomotives, and aircraft) or information
supplied by contractors (for marine vessels, locomotives, and
aircraft). Biogenic emissions were not included in the emission
inventories since these emissions are assumed to remain constant over
time (biogenic emissions are not included in the 2002, 2008, 2015, and
2025 emissions summarized in this proposed rule).
    The 2002 and 2008 Chicago area emissions (covering only the
Illinois portion of the Chicago-Gary-Lake County, IL-IN area) are
summarized in tables 3 through 5 below. All emissions are in units of
TPY. All summarized emissions are documented in Illinois' August 17,
2011 ``Maintenance Plan for the Chicago Nonattainment Area for the

1997 PM2.5 National Ambient Air Quality Standards
(Revised).''

         Table 3--Comparison of 2002 and 2008 NOX Emission Totals for the Chicago Area by Source Sector
                                                      (TPY)
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                          Source sector                                2002            2008          2002-2008
----------------------------------------------------------------------------------------------------------------
Point Sources...................................................          54,050          35,939         -18,111
Area Sources....................................................          32,325          32,318              -7
On-Road Mobile Sources..........................................         187,632         127,951         -59,681
Off-Road Mobile Sources.........................................          87,426          51,184         -36,242
----------------------------------------------------------------------------------------------------------------
    Total.......................................................         361,433         247,391        -114,042
----------------------------------------------------------------------------------------------------------------

    Table 4--Comparison of 2002 and 2008 Primary PM2.5 Emission Totals for the Chicago Area by Source Sector
                                                      (TPY)
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                          Source sector                                2002            2008          2002-2008
----------------------------------------------------------------------------------------------------------------
Point Sources...................................................           2,757           3,859           1,102
Area Sources....................................................          22,356           9,189         -13,167
On-Road Mobile Sources..........................................           6,573           5,100          -1,473
Off-Road Mobile Sources.........................................           4,834           3,653          -1,181
----------------------------------------------------------------------------------------------------------------
    Total.......................................................          36,520          21,800         -14,720
----------------------------------------------------------------------------------------------------------------

         Table 5--Comparison of 2002 and 2008 SO2 Emission Totals for the Chicago Area by Source Sector
                                                      (TPY)
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
                          Source sector                                2002            2008          2002-2008
----------------------------------------------------------------------------------------------------------------
Point Sources...................................................         121,598          90,706         -30,892
Area Sources....................................................           3,290           4,109             819
On-Road Mobile Sources..........................................           4,472             537          -3,935
Off-Road Mobile Sources.........................................           3,743             779           -2964
----------------------------------------------------------------------------------------------------------------
    Total.......................................................         133,103          96,130         -36,973
----------------------------------------------------------------------------------------------------------------

    Tables 3 through 5 show that NOX, SO2, and
primary PM2.5 emissions in the Chicago area have decreased
significantly between 2002 and 2008.
    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 Chicago-Gary-Lake County, IL-IN area. To
assess the change in regional emissions from states believed to
significantly contribute to annual PM2.5 concentrations in
the Chicago-Gary-Lake County, IL-IN area, we have considered statewide
NOX and SO2 emissions from EGUs reported for 2002
and 2008 in EPA's ARP/CAIR database. To limit the number of states
considered, we have selected those states with emissions that have been
modeled to have significantly contributed to elevated PM2.5
concentrations in Cook County, Illinois (a modeling receptor site
considered to be representative of the regional transport into the
Chicago-Gary-Lake County, IL-IN area. Table 6 summarizes statewide
NOX and SO2 emissions for EGUs previously
summarized in the proposed rule for the redesignation of Lake and
Porter Counties, Indiana to attainment of the 1997 annual
PM2.5 standard. See 76 FR 59600, 59608-59609, September 27,
2011.

                                                   Table 6--Statewide EGU Emissions for 2002 and 2008
                                                                          (TPY)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                NOX                                             SO2
                                                         -----------------------------------------------------------------------------------------------
                          State                                                               Percent                                         Percent
                                                               2002            2008          reduction         2002            2008          reduction
--------------------------------------------------------------------------------------------------------------------------------------------------------
Illinois................................................         174,246         119,930            31.2         353,699         257,357            27.2
Indiana.................................................         281,146         190,092            32.4         778,868         565,459            27.4
Iowa....................................................          78,956          49,023            37.9         127,847         109,293            14.5
Kentucky................................................         198,598         157,903            21.4         482,653         344,356            28.7
Michigan................................................         132,623         107,623            18.9         342,998         326,500             4.8

Minnesota...............................................          86,663          60,230            30.5         101,285          71,926            29.0
Ohio....................................................         370,497         235,049            36.6       1,132,069         709,914            37.3
Pennsylvania............................................         200,909         183,658             8.6         889,765         831,914             6.5
Wisconsin...............................................          88,970          47,794            46.3         181,256         129,693            32.1
                                                         -----------------------------------------------------------------------------------------------
    Total...............................................       1,612,708       1,151,302            28.6       4,400,440       3,346,412            24.0
--------------------------------------------------------------------------------------------------------------------------------------------------------

    As can be seen in table 6, the implementation of CAIR resulted in
significant reductions in regional, statewide NOX and
SO2 emissions from EGUs in the states EPA finds are
contributing significantly to the annual PM2.5
concentrations in the Chicago-Gary-Lake County, IL-IN area. Since CAIR
remains in place until EPA can replace it with an acceptable new
region-wide emissions control rule, we believe these emission
reductions to be permanent and enforceable.
    Based on the information summarized above, primary PM2.5
and precursor PM2.5 emissions (SO2 and
NOX) have significantly decreased between 2002 and 2008 in
the Chicago area and in states with EGU emissions significantly
impacting the annual PM2.5 concentrations in the Chicago
area.
b. VOC and Ammonia Emission Reductions
    For several reasons, we believe that VOC emission reductions in the
Chicago area and in upwind states have also contributed to the observed
improvement in annual PM2.5 concentrations in the Chicago
area and in the Chicago-Gary-Lake County, IL-IN area as a whole. In
addition, for several reasons, we also believe that changes in ammonia
emissions have not significantly impacted the observed annual
PM2.5 concentrations in these areas.
    First, as noted elsewhere in this proposed rule in EPA's discussion
of section 189(e) of the CAA, VOC emissions in the Chicago area have
historically been well-controlled under SIP requirements related to
ozone and other pollutants.\16\ Second, total ammonia emissions
throughout the Chicago area are very low, estimated to be 9,885.71 TPY
in 2002. See table 12 below. This amount of ammonia emissions appears
especially small in comparison to the total amounts of SO2,
NOX, and even direct PM2.5 emissions in the area
in 2002. 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.
---------------------------------------------------------------------------

    \16\ For a thorough discussion of VOC emission controls and
estimates (2002 and 2008) and projected (2015, 2020, and 2025) VOC
emission levels (summertime emissions) in the Chicago area, see
EPA's proposed rule for the redesignation of the Chicago area to
attainment of the 1997 8-hour ozone standard (77 FR 6743, February
9, 2012). We observe here that the estimated/projected summertime
VOC emission reductions in the Chicago area also generally reflect
reductions in annual emissions of VOC in this area.
---------------------------------------------------------------------------

c. Conclusions Regarding Emission Reductions Between 2002 and 2005 in
the Chicago Area
    In summary, emissions data provided by the state support the
conclusion that significant reductions in the emissions of
SO2, NOX, primary PM2.5, and VOC
occurred in the Chicago area between 2002 and 2008. During the same
period, emissions of ammonia are believed to have had minimal impact on
PM2.5 concentrations in the Chicago area. We believe that
the emission reductions of the significant PM2.5 precursors
and primary PM2.5 in the Chicago area and in upwind states
are responsible for the observed improvement in annual PM2.5
concentrations in the Chicago-Gary-Lake County, IL-IN area. For the
reasons set forth above, we conclude that the attainment of the 1997
annual PM2.5 standard in the Chicago area can be explained
on the basis of permanent and enforceable emission reductions within
the Chicago area and in the states regulated by CAIR.

D. Does Illinois have a fully approvable PM2.5 maintenance
plan pursuant to section 175A of the CAA for the Chicago area?

    In conjunction with Illinois' request to redesignate the Chicago
area to attainment of the 1997 annual PM2.5 standard, IEPA
submitted a SIP revision to provide for maintenance of the 1997 annual
PM2.5 standard in the Chicago-Gary-Lake County, IL-IN area
through 2025. This maintenance plan demonstrates that emissions in the
Chicago area will 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 Chicago-Gary-Lake
County, IL-IN 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
redesignations 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 of 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 September 4, 1992, Calcagni memorandum provides additional
guidance on the content of a maintenance plan. The memorandum states
that a maintenance plan should address the following items: (1) The
attainment emission inventories; (2) a maintenance demonstration
showing maintenance of the standard for the 10 years of the maintenance
period; (3) a commitment to maintain the existing monitoring network;
(4) the factors and procedures to be used for verification of continued
attainment of the standard; and (5) a contingency plan to prevent or
correct future violations of the standard.

2. Attainment Inventory
    As noted above, IEPA 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. The 2008 emissions are summarized in tables
3 through 5 above.
3. Demonstration of Maintenance
    Along with the redesignation request, IEPA submitted a maintenance
plan dated August 17, 2011, which includes a demonstration of
maintenance for the Chicago area, as required by section 175A of the
CAA. This demonstration shows maintenance of the 1997 annual
PM2.5 standard through 2025 by showing that current and
future emissions of NOX, SO2, and primary
PM2.5 emissions for the Chicago 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).
    Illinois used emission projections for 2015, 2020, and 2025 to
demonstrate maintenance. For each of the applicable PM2.5
precursors (pollutants), IEPA prepared emission estimates for the same
source sectors used by IEPA for the 2008 attainment year. IEPA assumed
biogenic emissions to remain constant, and did not consider them in the
maintenance demonstration analysis.
    IEPA used EPA's MOVES 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
projected on-road mobile source emissions assume the continued use of
reformulated gasoline, the continued phase-in of the Tier 2 motor
vehicle emission standards, and the operation of an enhanced vehicle
inspection and maintenance program in the Chicago area. Total VMT for
2015, 2020, and 2025 were derived by assuming that the VMT will
increase at a rate of 1.5 percent per year after 2008. The 2008 and
2025 on-road mobile source emissions were used to establish MVEBs for
the Chicago area. See the additional discussion of the MVEBs in section
V.E of this proposed rule.
    Chicago area point and area source emissions for 2015, 2020, and
2025 were estimated using the 2008 attainment year emissions and growth
factors appropriate for each source category. Off-road emission
projections were developed using the growth factors contained in EPA's
NONROAD model.
    Tables 7 through 9 summarize the projected NOX,
SO2, and primary PM2.5 emissions for 2008, 2015,
2020, and 2025 by source sector.

   Table 7--Comparison of 2008, 2015, 2020, and 2025 NOX Emissions by Source Sector (TPY) for the Chicago Area
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
          Source sector                2008            2015            2020            2025          2008-2025
----------------------------------------------------------------------------------------------------------------
Point Sources...................          35,939          27,082          28,500          29,638          -6,301
Area Sources....................          32,318          32,997          33,277          33,687           1,369
On-Road Mobile..................         127,951          68,491          40,599          38,456         -89,495
Off-Road Mobile.................          51,184          35,927          28,271          27,173         -24,011
                                 -------------------------------------------------------------------------------
    Totals......................         247,391         164,497         130,648         128,954        -118,437
----------------------------------------------------------------------------------------------------------------

   Table 8--Comparison of 2008, 2015, 2020, and 2025 SO2 Emissions by Source Sector (TPY) for the Chicago Area
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
          Source sector                2008            2015            2020            2025          2008-2025
----------------------------------------------------------------------------------------------------------------
Point Sources...................          90,706          58,092          53,452          56,310         -34,396
Area Sources....................           4,109           4,266           4,332           4,407             298
On-Road Mobile..................             537             504             477             488             -49
Off-Road Mobile.................             779             866             919           1,215             436
                                 -------------------------------------------------------------------------------
    Totals......................          96,130          63,727          59,180          62,420         -33,710
----------------------------------------------------------------------------------------------------------------

Table 9--Comparison of 2008, 2015, 2020, and 2025 Primary PM2.5 Emissions by Source Sector (TPY) for the Chicago
                                                      Area
----------------------------------------------------------------------------------------------------------------
                                                                                Net change
          Source sector                2008            2015            2020            2025          2008-2025
----------------------------------------------------------------------------------------------------------------
Point Sources...................           3,859           4,169           4,391           4,604             745
Area Sources....................           9,189           9,676          10,009          10,377           1,188
On-Road Mobile..................           5,100           3,071           2,119           2,067          -3,033
Off-Road Mobile.................           3,653           2,995           2,398           2,267          -1,386
                                 -------------------------------------------------------------------------------
    Totals......................          21,800          19,911          18,918          19,316          -2,484
----------------------------------------------------------------------------------------------------------------

    Comparison of the 2008 and projected 2015, 2020, and 2025 emissions
demonstrates that future NOX, SO2, and primary
PM2.5 emissions through 2025 will remain below the 2008
levels in the Chicago area.
    In a September 27, 2011 proposed rulemaking (76 FR 59600, 59610)
for the redesignation of Lake and Porter Counties, Indiana (the Indiana
portion of the Chicago-Gary-Lake County, IL-IN area) to attainment of
the 1997 annual

PM2.5 standard, we also evaluated the 2008, 2015, 2020, and
2025 emissions for the entire Chicago-Gary-Lake County, IL-IN area.
Table 10 repeats the summary of the area's emission totals as
documented in the September 27, 2011 proposed rule.

                Table 10--Chicago-Gary-Lake County, IL-IN Area 2008 and Projected Emission Totals
                                                      [TPY]
----------------------------------------------------------------------------------------------------------------
                           Year                                    NOX               SO2          Primary PM2.5
----------------------------------------------------------------------------------------------------------------
2008......................................................        278,649.74        152,367.68         32,069.68
2015......................................................        187,557.31        107,285.55         25,128.65
2020......................................................        156,231.26         98,829.89         24,729.26
2025......................................................        149,198.79         99,453.24         25,074.10
----------------------------------------------------------------------------------------------------------------

    Tables 7 through 10 show that emissions will remain at or below
2008 emission levels in the Chicago area and in the Chicago-Gary-Lake
County, IL-IN area through 2025. Therefore, the state has demonstrated
maintenance of the 1997 annual PM2.5 standard for a period
extending ten years and beyond from the time EPA may be expected to
complete rulemaking on the state's PM2.5 redesignation
request.
4. Monitoring Network
    Illinois commits to continue monitoring PM2.5 levels
according to the EPA-approved monitoring plan, as required to ensure
maintenance of the 1997 annual PM2.5 standard. If changes
are needed in the PM2.5 monitoring network, the IEPA 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 Chicago area and in the Chicago-Gary-Lake County, IL-IN area
depends, in part, on the state's efforts toward tracking indicators of
continued attainment during the maintenance period. Illinois' plan for
verifying continued attainment of the standard in these areas 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 PM2.5, SO2 and
NOX emissions inventories for the Chicago area, as required
by the Federal Consolidated Emission Reporting Rule (codified at 40 CFR
51 subpart A).
6. Contingency Plan
    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 might occur
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 controlled through the SIP before
redesignation of the area to attainment. See section 175A(d) of the
CAA.
    As required by section 175A of the CAA, Illinois has adopted a
contingency plan for the Chicago area to address possible future
violations of the 1997 annual PM2.5 standard. The
contingency plan provides for two levels of action. A Level I response
would be triggered whenever: (1) The highest monitored PM2.5
concentration in any year at any monitoring station in the Chicago
maintenance area exceeds 15 [micro]g/m\3\; or (2) the Chicago
maintenance area's total PM2.5, SO2 or
NOX emissions increase more than 5 percent above the 2008
emissions. A Level I trigger will result in an evaluation of current
PM2.5 air quality and/or emission trends to determine if
adverse emission trends are likely to continue. If so, Illinois will
determine what and where controls may be required, as well as level of
emissions reductions needed, to avoid a violation of the NAAQS. The
study will be completed within 9 months. If necessary, control measures
will be adopted within 18 months of determination of the Level I
triggering and implemented as expeditiously as practicable, taking into
consideration the ease of implementation and the technical and economic
feasibility of the selected measures.
    A Level II response will be triggered if a violation of the 1997
annual PM2.5 standard occurs at any monitoring station in
the Chicago maintenance area. If triggered, Illinois will conduct an
analysis to determine appropriate measures to address the cause of the
violation. Analysis will be completed within six months. Selected
control measures will be implemented within 18 months of the violation.
Potential control measures contained in Illinois' contingency plan
include the following:

 Illinois' Multi-Pollutant Program for EGUs
 NOX RACT
 Best Available Retrofit Technology (BART)
 Broader geographic applicability of existing control measures
 Tier 2 vehicle standards and low sulfur fuel standard
 Heavy duty diesel standards and low sulfur diesel fuel
standard
 High-enhanced vehicle inspection/maintenance (On-board
Diagnostics II (OBDII))
 Federal railroad/locomotive standards
 Federal commercial marine vessel engine standards
 Architectural/Industrial Maintenance (AIM) coatings
 Commercial and consumer products rules
 Aerosol coating rules, and
 Portable fuel container rules.

Note that some of these rules are Federal rules and are already being
implemented. If a future violation of the 1997 annual PM2.5
occurs, IEPA will analyze the future emission reduction potential from
these rules to determine if these future emission reductions will be
sufficient to mitigate the PM2.5 air quality problem.
    EPA believes that Illinois' 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, Illinois commits to
submit to EPA an updated maintenance plan eight years after EPA
redesignates the Chicago area to attainment of the 1997 annual
standard. The revised maintenance plan is intended to cover an
additional 10-year period beyond the initial 10-year maintenance
period. As required by section 175A of the CAA, Illinois has also
committed to retain and implement

the emission control measures contained in the maintenance plan. If
changes are needed in the control measures, Illinois commits to submit
these changes to EPA as requested SIP revisions and to demonstrate that
these emission control measure revisions will not interfere with the
maintenance of the 1997 annual PM2.5 standard in the
Chicago-Gary-Lake County, IL-IN area.
    Finally, the state affirms that Illinois has the legal authority to
implement and enforce the requirements of the maintenance plan pursuant
to the Illinois Environmental Protection Act.
8. CAIR and CSAPR
a. 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 Chicago area redesignation request and Illinois'
PM2.5 maintenance plan rely on emission reductions
associated with CAIR, EPA 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