Approval and Promulgation of Air Quality Implementation Plans; Indiana; Redesignation of Lake and Porter Counties to Attainment of the Fine Particulate Matter Standard, 59600-59614 [2011-24376]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 76, Number 187 (Tuesday, September 27, 2011)]
[Proposed Rules]
[Pages 59600-59614]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-24376]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R05-OAR-2008-0395; FRL-9469-8]


Approval and Promulgation of Air Quality Implementation Plans; 
Indiana; Redesignation of Lake and Porter Counties to Attainment of the 
Fine Particulate Matter Standard

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: In an April 3, 2008, submittal, supplemented on March 6, 2009, 
May 26, 2011, and July 20, 2011, the Indiana Department of 
Environmental Management (IDEM) requested redesignation of the Lake and 
Porter Counties, Indiana portion (Lake and Porter Counties) of the 
Chicago-Gary-Lake County, Illinos-Indiana (IL-IN) nonattainment area 
(Greater Chicago nonattainment area) to attainment of the 1997 annual 
fine particulate matter (PM2.5) National Ambient Air Quality 
Standard (NAAQS or standard). EPA is proposing to approve the 
redesignation request for Lake and Porter Counties, along with related 
Indiana State Implementation Plan (SIP) revisions, including the 
State's plan for maintaining attainment of the PM2.5 
standard in this area through 2025, because the request meets the 
statutory requirements for redesignation under the Clean Air Act (CAA). 
EPA is also proposing to approve Indiana's 2025 Nitrogen Oxides 
(NOX) and PM2.5 Motor Vehicle Emission Budgets 
(MVEBs) for Lake and Porter Counties, as well as the 2005 
PM2.5-related emissions inventories for this area.

DATES: Comments must be received on or before October 27, 2011.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2008-0395, by one of the following methods:
     https://https://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     E-mail: Mooney.John@epa.gov.
     Fax: (312) 692-2551.
     Mail: John Mooney, Chief, Air Programs Branch (AR-18J), 
U.S. Environmental Protection Agency, 77 West Jackson Boulevard, 
Chicago, Illinois 60604.
     Hand Delivery: John Mooney, 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-
2008-0395. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
https://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 https://www.regulations.gov or e-mail. The https://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 e-mail comment directly to EPA without 
going through https://www.regulations.gov, your e-mail 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

[[Page 59601]]

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 https://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 https://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 (312) 886-6057 
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, (312) 886-6057, or 
Doty.Edward@epa.gov.

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?
    A. Fine Particulate Standards and Regional Emission Controls
    B. Background for Indiana's PM2.5 Redesignation 
Request and Maintenance Plan
IV. What are the criteria for redesignation to attainment?
V. Review of the State's PM2.5 Redesignation Request and 
Basis for EPA's Proposed Actions
    A. Has the greater Chicago nonattainment area attained the 1997 
annual PM2.5 standard?
    B. Have Lake and Porter Counties and the State of Indiana met 
all requirements of Section 110 and Part D of the CAA applicable for 
purposes of redesignation, and do Lake and Porter Counties have a 
fully approved SIP under Section 110(k) of the CAA for purposes of 
redesignation to attainment?
    C. Are the PM2.5 air quality improvements in the 
Chicago-Gary-Lake County, IL-IN area due to permanent and 
enforceable emission reductions?
    D. Does Indiana have a fully approvable PM2.5 
maintenance plan pursuant to Section 175A of the CAA for Lake and 
Porter Counties?
VI. Has the State adopted acceptable MVEBs for the PM2.5 
maintenance period?
VII. Are the base year emissions inventories for Lake and Porter 
Counties approvable under CAA Section 172(c)(3)?
VIII. What are EPA's proposed actions and what are the effects of 
these proposed actions?
IX. Statutory and Executive Order Reviews

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

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

II. What actions is EPA proposing?

    On November 27, 2009, at 74 FR 62243, EPA made a final 
determination that the Greater Chicago nonattainment area, which 
includes Lake and Porter Counties in Indiana, was attaining the 1997 
annual PM2.5 standard. EPA is proposing here to determine 
that this area continues to attain this standard. EPA is also proposing 
to take several additional actions related to Indiana's 
PM2.5 redesignation request, as discussed below. In a 
separate proposed rule, EPA will address an Illinois PM2.5 
redesignation request for the Illinois portion of the Greater Chicago 
nonattainment area.
    EPA is proposing to approve Indiana's 1997 annual PM2.5 
standard maintenance plan for Lake and Porter Counties as a revision of 
the Indiana SIP meeting the requirements of section 175A of the CAA. 
The maintenance plan, as revised in the May 26, 2011, submittal, 
assumes that control of power plant emissions resulting from the 
implementation of EPA's Cross-State Air Pollution Rule (CSAPR) will 
replace existing power plant emission control requirements that would 
have resulted from EPA's Clean Air Interstate Rule (CAIR). See 
discussions of CAIR and CSAPR and their relation to Indiana's 
PM2.5 redesignation request and maintenance plan later in 
this proposed rule.
    EPA is proposing to approve 2005 emissions inventories for primary 
PM2.5,\1\ NOX, and sulfur dioxide 
(SO2),\2\ documented in Indiana's May 26, 2011, 
PM2.5 redesignation request submittal, as satisfying the 
requirement in section 172(c)(3) of the CAA for a comprehensive, 
current, and accurate emission inventory.
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    \1\ Primary PM2.5 are fine particulates directly 
emitted by sources and are not formed in a secondary manner through 
chemical reactions or other processes in the atmosphere.
    \2\ NOX and SO2 are precursors for fine 
particulates formed through chemical reactions and other related 
processes in the atmosphere.
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    EPA is proposing to find that Indiana meets the requirements for 
redesignation of Lake and Porter Counties to attainment of the 1997 
annual PM2.5 standard under section 107(d)(3)(E) of the CAA. 
We are making this proposal despite the fact that Indiana, in part, 
relied on emission reductions from CAIR to demonstrate, under section 
107(d)(3)(E)(iii) of the CAA, that permanent and enforceable emission 
reductions were responsible for the monitored improvements in the 
PM2.5 air quality of the Greater Chicago nonattainment area. 
As will be discussed further below, because CAIR was remanded by the 
United States Court of Appeals for the District of Columbia Circuit 
(D.C. Circuit), the emission reductions associated with that rule 
cannot be considered to be permanent and enforceable.
    EPA, however, proposes that this requirement has effectively been 
met because the emission reductions of CAIR continue through 2011, and 
CSAPR requires similar or greater reductions in the relevant areas in 
2012 and beyond. Because the emission reduction requirements of CAIR 
are enforceable through 2011, and because CSAPR has now been 
promulgated to address the emission reduction requirements previously 
addressed by CAIR and gets similar or greater emission reductions in 
the relevant areas in 2012 and beyond, EPA is

[[Page 59602]]

proposing to determine that the emission reductions that led to 
attainment of the 1997 annual PM2.5 standard in the Greater 
Chicago nonattainment area can now be considered to be permanent and 
enforceable. For this reason, EPA is proposing to determine that the 
requirement of CAA section 107(d)(3)(D)(iii) has now been met. 
Therefore, EPA is proposing to approve the request from the State of 
Indiana to change the designation of Lake and Porter Counties from 
nonattainment to attainment of the 1997 annual PM2.5 NAAQS.
    Finally, EPA is proposing to approve 2025 primary PM2.5 
and NOX MVEBs for Lake and Porter Counties documented in 
Indiana's PM2.5 maintenance plan, as submitted on May 26, 
2011. These MVEBs will be used in future transportation conformity 
analyses for these counties.

III. What is the background for these actions?

A. Fine Particulate Standards and Regional Emission Controls

    The first air quality standards for PM2.5 were 
promulgated on July 18, 1997, at 62 FR 38652. EPA promulgated an annual 
standard at a level of 15 micrograms per cubic meter ([mu]g/m\3\) of 
ambient air, based on a three-year average of the annual mean 
PM2.5 concentrations at each monitoring site (1997 annual 
PM2.5 standard). In the same rulemaking, EPA promulgated a 
24-hour PM2.5 standard, at 65 [mu]g/m\3\, based on a three-
year average of the annual 98th percentile of 24-hour PM2.5 
concentrations at each monitoring site. On October 17, 2006, at 71 FR 
61144, EPA retained the annual PM2.5 standard at 15 [mu]g/
m\3\ (2006 annual PM2.5 standard), but revised the 24-hour 
standard to 35 [mu]g/m\3\, based again on the three-year average of the 
annual 98th percentile of the 24-hour PM2.5 concentrations.
    On January 5, 2005, at 70 FR 944, EPA published air quality area 
designations and classifications for the 1997 annual PM2.5 
standard based on air quality data for calendar years 2001-2003. In 
that rulemaking, EPA designated the Greater Chicago area as 
nonattainment for the 1997 annual PM2.5 standard.
    In response to legal challenges of the 2006 annual PM2.5 
standard, the DC 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). 
However, given that the 1997 and 2006 annual PM2.5 standards 
are essentially identical, attainment of the 1997 annual 
PM2.5 standard also indicates attainment of the remanded 
2006 annual standard. Since the Greater Chicago area is designated as 
nonattainment only for the 1997 annual PM2.5 standard, 
today's proposed action addresses redesignation to attainment only for 
this standard, and, as noted above, only for the Indiana portion of 
this nonattainment area.
    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 emitted from 
a variety of sources. Sulfates are a type of secondary particulate 
formed from SO2 emissions from power plants and industrial 
facilities. Nitrates, another common type of secondary particulate, are 
formed from combustion emissions of NOX from power plants, 
mobile sources, and other combustion sources.
    Given the significance of sulfates and nitrates in the formation of 
PM2.5 in and transport of PM2.5 into the Greater 
Chicago nonattainment area, the regulation of SO2 and 
NOX emissions from power plants strongly affects the area's 
air quality. 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 to improve air quality in many areas across Eastern 
United States. However, on July 11, 2008, the D.C. Circuit issued its 
decision to vacate and remand both CAIR and the associated CAIR FIPs in 
their entirety (North Carolina v. EPA, 531 F.3d 836 (D.C. Cir. 2008)). 
EPA petitioned for a rehearing, and the court issued an order remanding 
CAIR and the CAIR FIPs to EPA without vacatur (North Carolina v. EPA, 
550 F.3d 1176 (D.C. Cir. 2008)). The court, 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). As a result 
of these court rulings, the power plant emission reductions that 
resulted solely from the development, promulgation, and implementation 
of CAIR, and the associated air quality improvement that occurred 
solely as a result of CAIR in the Greater Chicago nonattainment area 
and elsewhere with emissions contributing to PM2.5 
concentrations in this area could not be considered to be permanent.
    On August 8, 2011, at 75 FR 48208, EPA promulgated CSAPR to address 
interstate transport of emissions and resulting secondary air 
pollutants and to replace CAIR. CAIR, among other things, required 
NOX emission reductions that contributed to the air quality 
improvement in the Greater Chicago nonattainment area. CAIR emission 
reduction requirements limit emissions through 2011, and EPA has now 
promulgated CSAPR, which requires similar or greater emission 
reductions in the relevant areas in 2012 and beyond. CSAPR requires 
substantial reductions of SO2 and NOX emissions 
from Electric Generating Units (EGUs or power plants) across most of 
the Eastern United States, with implementation beginning on January 1, 
2012. By 2014, EGUs in states common to both CSAPR and CAIR will 
achieve annual SO2 emission reductions of approximately 1.8 
million tons, and will achieve annual NOX emission 
reductions of approximately 76,000 tons beyond those that would have 
been achieved by CAIR by that time. CAIR will continue to be 
implemented through 2011, and will be replaced by CSAPR beginnig in 
2012.
    As demonstrated later in this proposed rule, CSAPR requires 
reduction of NOX and SO2 emissions to levels well 
below the levels that led to attainment of the 1997 annual 
PM2.5 standard in the Greater Chicago nonattainment area. 
The emission reductions that CSAPR mandates may be considered to be 
permanent and enforceable. In turn, the air quality improvement in the 
Greater Chicago nonattainment area that has resulted from EGU emission 
reductions to date (as well as the substantial further air quality 
improvement that would be expected to result from full implementation 
of CSAPR) may also be considered to be permanent and enforceable.

B. Background for Indiana's PM2.5 Redesignation Request and Maintenance 
Plan

    On April 3, 2008, IDEM submitted a request for EPA approval of a 
redesignation of Lake and Porter Counties to attainment of the 1997 
annual PM2.5 standard. This redesignation request is based 
on 2004-2007 monitoring data showing attainment of the standard 
throughout the Greater Chicago nonattainment area. On March 6, 2009, 
IDEM submitted a technical addendum to the April 3, 2008, 
PM2.5 redesignation request to show that the Greater Chicago 
nonattainment area continued to attain

[[Page 59603]]

the 1997 annual PM2.5 standard through 2008.
    In addition to showing that this area has attained the 1997 annual 
PM2.5 standard, the April 3, 2008, State submittal also 
seeks to demonstrate that Indiana has met all other CAA requirements 
for redesignation of Lake and Porter Counties to attainment of the 1997 
annual PM2.5 standard. The redesignation request includes a 
maintenance plan for Lake and Porter Counties demonstrating maintenance 
of the 1997 annual PM2.5 standard through 2020. Both the 
redesignation request and the maintenance demonstration rely on 
emission reductions resulting from CAIR to demonstrate the basis for 
the attainment of the 1997 annual PM2.5 standard and to 
demonstrate maintenance of this standard.
    Before EPA could rule on the August 3, 2008, redesignation request, 
as amended in the March 6, 2009, supplemental submittal, the D.C. 
Circuit remanded CAIR to EPA for reconsideration. This raised questions 
about the emission reduction credits resulting from CAIR assumed in 
Indiana's PM2.5 redesignation request and maintenance plan. 
As time passed without resolution of the CAIR issue, EPA also became 
concerned about the period covered by Indiana's PM2.5 
maintenance demonstration, which must, at a minimum, demonstrate 
attainment of the 1997 annual PM2.5 standard for at least 
ten years after EPA approves the State's PM2.5 redesignation 
request. See section 175A(a) of the CAA. This necessitated a revision 
of the PM2.5 maintenance plan by the State to extend the 
maintenance demonstration to a later endpoint.
    On May 26, 2011, IDEM submitted a revised PM2.5 
maintenance plan to EPA demonstrating maintenance of the 1997 annual 
PM2.5 in Lake and Porter Counties through 2025. In this 
submittal, the State included additional air quality data showing 
continued attainment of the 1997 annual PM2.5 standard in 
the Greater Chicago nonattainment area during 2008-2010.
    The State held a public hearing on the PM2.5 
redesignation request and maintenance plan on May 18, 2011, and the 
State's public comment period on these submittal elements ended on May 
20, 2011. Following the close of the public comment period, Indiana 
submitted a revised PM2.5 redesignation request and final 
PM2.5 maintenance plan for Lake and Porter Counties on July 
20, 2011.
    Indiana requests that the maintenance plan be approved by EPA as a 
revision of the Indiana SIP. The maintenance plan documents 2025 
PM2.5 and NOX MVEBs, which IDEM requests EPA to 
approve and find adequate for use in transportation conformity 
determinations and demonstrations.\3\
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    \3\ Transportation conformity assures that emissions from on-
road mobile sources do not jeopardize continued maintenance of the 
standard during the maintenance period.
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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. Specifically, section 107(d)(3)(E) of 
the CAA allows redesignation to attainment provided that: (1) The 
Administrator determines that the area has attained the applicable 
NAAQS; (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 emission 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. Review of the State's PM2.5 Redesignation Request and 
Basis for EPA's Proposed Actions

A. Has the Greater Chicago nonattainment area attained the 1997 annual 
PM2.5 standard?

    In a final rulemaking dated November 27, 2009, at 76 FR 62243, EPA 
determined that the Greater Chicago nonattainment area had attained the 
1997 annual PM2.5 standard. This determination was based on 
complete, quality-assured air monitoring data for 2006-2008.
    The April 3, 2008, IDEM PM2.5 redesignation request 
presents PM2.5 data for the period of 2005-2007, and the May 
26, 2011, IDEM submittal presents PM2.5 data for the period 
of 2008-2010. These quality-assured data show that the Greater Chicago 
nonattainment area attained the 1997 annual PM2.5 standard 
beginning in 2005-2007, and has continued to attain through 2010. 
Preliminary data available for 2011 are consistent with continued 
attainment.
    Table 1 provides a summary of the PM2.5 annual air 
quality data for the area for the period of 2008-2010.

             Table 1--PM2.5 Annual Average Concentrations for the Greater Chicago Nonattainment Area
                                                 (in [mu]g/m\3\)
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                                    Monitoring site AQS site                                            3-Year
              County                         number               2008         2009         2010       average
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                                            Indiana Monitoring Sites
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Lake.............................  Franklin School,                 11.95        11.34        12.48         11.9
                                    180890006.
Lake.............................  Griffith, 180890027......        11.69        11.00        12.39         11.7
Lake.............................  Hammond-Purdue, 180892004        11.66          (1)        12.30          (1)
Lake.............................  Hammond-Clark High               12.42        10.80        11.90         11.7
                                    School, 180892010.
Lake.............................  Gary-Madison Street,             12.27        12.12        12.90         12.4
                                    180890031.
Porter...........................  Ogden Dunes, 181270024...        10.89        11.29        11.56         11.2
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                                            Illinois Monitoring Sites
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Cook.............................  Chicago-Washington High          12.54        11.62        14.04         12.7
                                    School, 170310022.
Cook.............................  Chicago-Southeast Police         11.80        10.99        12.47         11.8
                                    Station, 170310050.
Cook.............................  Chicago-Mayfair Pump             12.18        12.69        12.57         12.5
                                    Station, 170310052.
Cook.............................  Chicago-Springfield Pump         12.03        11.33    \1\ 12.03     \1\ 11.8
                                    Station, 170310057.

[[Page 59604]]

 
Cook.............................  Chicago-Commonwealth             11.89        11.12        12.25         11.8
                                    Edison Maintenance
                                    Building, 170310076.
Cook.............................  Blue Island, 170312001...        12.50        11.68        11.59         11.9
Cook.............................  Schiller Park, 170313103.        13.59        12.91        12.64         13.0
Cook.............................  Summit, 170313301........        12.03        11.62        12.23         12.0
Cook.............................  Des Plaines, 170314007...        11.35        11.02        10.60         11.0
Cook.............................  Northbrook, 170314201....        10.09         9.33         9.34          9.6
Cook.............................  Cicero, 170316005........    \1\ 13.25    \1\ 11.98        11.90     \1\ 12.4
DuPage...........................  Naperville, 170434002....        11.28         9.83        11.67         10.9
Kane.............................  Elgin, 170890003.........        10.79         9.61        11.29         10.6
Kane.............................  Aurora, 170890007........        10.34        10.01        11.44         10.6
Lake.............................  Zion, 170971007..........         9.34         8.83         9.66          9.3
McHenry..........................  Cary, 171110001..........        10.10         9.65        10.24         10.0
Will.............................  Joliet, 171971002........        11.66        10.52        11.83         11.3
Will.............................  Braidwood, 171971011.....        10.31         8.73        10.02          9.7
----------------------------------------------------------------------------------------------------------------
Notes: (1) The data for these sites and/or years do not meet data completeness requirements.

    The data in table 1 show that all PM2.5 monitors in the 
Greater Chicago nonattainment area have recorded PM2.5 
concentrations attaining the 1997 annual PM2.5 standard 
during 2008-2010. These annual average PM2.5 concentrations 
are based on PM2.5 monitoring data that have been quality 
assured and stored in EPA's Air Quality System (AQS) database.
    Further consideration of annual PM2.5 concentrations at 
several sites is necessary because data at these sites do not meet EPA 
data completeness requirements. Under 40 CFR part 50, appendix N, 
section 4.1 (addressing the annual PM2.5 standard), a year 
of PM2.5 data meets completeness requirements when ``at 
least 75 percent of the scheduled sampling days for each quarter has 
valid data.'' As noted in table 1, three sites in the Greater Chicago 
nonattainment area did not meet this data completeness requirement for 
one or more years: the Hammond-Purdue (180892004) sites, located in 
Lake County, Indiana; and, the Chicago-Springfield Pump Station 
(170310057) and Cicero (170316005) sites, both located in Cook County, 
Illinois.
    Data handling conventions and computations necessary for 
determining whether areas have met the 1997 annual PM2.5 
standard, including requirements for data completeness, are listed in 
appendix N of 40 CFR part 50. The use of less than complete data is 
subject to the approval of the EPA, which may consider factors such as 
monitoring site closures/moves, monitoring diligence, and nearby 
concentrations in determining whether to use such data, as set forth at 
40 CFR part 50, appendix N, section N.1(c).
    Two of the identified sites are similar in that they have only one 
year with incomplete data during the three years of data considered in 
table 1: 2009 for the Hammond-Purdue (Indiana) site; and, 2010 for the 
Chicago-Springfield Pump Station (Illinois) site. For these sites, we 
note that, for the three-year periods preceding the years with the 
missing data, each site had complete data showing attainment of the 
1997 annual PM2.5 standard. For the Hammond-Purdue site, 
complete 2006-2008 data show annual PM2.5 concentrations of 
12.67, 13.8, and 11.66 [micro]g/m\3\, with an average of 12.7 [micro]g/
m\3\ for the three-year period (see data tables on pages A-1 and A-2 of 
appendix A of Indiana's May 26, 2011, submittal). For the Chicago-
Springfield Pump Station site, complete 2007-2009 data show annual 
PM2.5 concentrations of 15.18, 12.03, and 11.33 [micro]g/
m\3\, with an average of 12.85 [micro]g/m\3\ for the three-year period 
(see data tables on pages A-6 and A-7 of appendix A of Indiana's May 
26, 2011, submittal). Therefore, both of these sites are able to show 
attainment of the standard with complete data for the preceding three-
year periods. For the 2008-2010 period, there are available complete 
data for nearby sites, such as Hammond-Clark High School and Chicago-
Mayfair Pump Station, that show attainment of the 1997 annual 
PM2.5 standard (See table 1). EPA, thus, concludes that the 
Hammond-Purdue and Chicago-Springfield Pump Station sites monitored 
attainment of the 1997 annual PM2.5 standard during 2008-
2010. EPA is using these data because it finds that the States of 
Indiana and Illinois have exercised due diligence in their monitoring, 
no monitoring site closures or moves were involved for these sites, and 
nearby PM2.5 concentrations suggest that the partial 
evidence of PM2.5 concentrations at the Hammond-Purdue and 
Chicago-Springfield Pump Station sites are indeed indicative that the 
1997 annual PM2.5 standard has been attained at these sites.
    For Cicero, both 2008 and 2009 have incomplete monitoring data. We 
previously determined that this site had attained the 1997 annual 
PM2.5 standard based on 2006-2008 monitoring data. See our 
proposed and final determination of attainment at 74 FR 48690 
(September 24, 2009) and at 74 FR 62243 (November 27, 2009). In the 
proposed determination, we discussed our analysis of PM2.5 
concentrations for the Cicero monitoring site and our conclusion that, 
although the PM2.5 data for this site did not meet EPA's 
data completeness criteria in 2008, it is likely that this site 
monitored attainment of the 1997 annual PM2.5 standard in 
2008 and throughout 2006-2008.
    EPA has conducted PM2.5 data substitution tests for the 
2009 PM2.5 data at the Cicero monitoring site (170316005), 
to evaluate how to address the issue of data completeness. The results 
helped EPA assess whether the Cicero monitoring site monitored 
attainment of the 1997 annual PM2.5 standard. On the basis 
of these tests, and additional factors discussed below, we have 
concluded that the data should be considered complete and should be 
approved for the purpose of showing that this site attained the 1997 
annual PM2.5 standard based on 2007-2009 and 2008-2010 
monitoring data. EPA is using these data because it finds that the 
State of Illinois has exercised due diligence in its monitoring, no 
monitoring site closures or moves were involved for this site, and 
nearby PM2.5

[[Page 59605]]

concentrations, such as those for the Blue Island monitoring site, 
suggest that the partial evidence of PM2.5 concentrations at 
the Cicero monitoring site are indeed indicative that the 1997 annual 
PM2.5 standard is being attained at this site. See 
PM2.5-related data links and spreadsheets with data for this 
monitoring site at: https://www.epa.gov/airtrends/values.html.
    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 based on quality-assured data for 2008-2010.

B. Have Lake and Porter Counties and the State of Indiana met all 
requirements of section 110 and part D of the CAA applicable for 
purposes of redesignation, and do Lake and Porter Counties have a fully 
approved SIP under section 110(k) of the CAA for purposes of 
redesignation to attainment?

1. General Requirements
    Sections 107(d)(3)(E)(ii) and 107(d)(3)(E)(v) of the CAA set forth 
related requirements that together require the State to have a fully 
approved SIP meeting all pertinent requirements under section 110 and 
part D of the CAA as a prerequisite for approval of the State's 
redesignation request. The following discussion addresses Indiana's 
satisfaction of these criteria.
    Since the passage of the CAA in 1970, Indiana has adopted and 
submitted, and EPA has fully approved, provisions addressing the 
various required SIP elements needed to attain the particulate 
standards in Lake and Porter Counties and elsewhere in Indiana. Indiana 
submitted the ``State of Indiana Air Pollution Control Implementation 
Plan,'' Indiana's SIP, on January 31, 1972. EPA approved Indiana's SIP 
on May 31, 1972 (37 FR 10863). Rules contained in this SIP addressed 
attaining the Total Suspended Particulate (TSP) standard, reflecting 
the particulate size range regulated under 1971 air quality standards.
    On July 1, 1987, EPA replaced the TSP standard with a standard for 
particles with aerodynamic diameters of 10 micrometers or smaller 
(PM10). EPA promulgated area designations under the 
PM10 NAAQS on March 15, 1991 (56 FR 11101). Lake County was 
designated and classified as moderate nonattainment for the 
PM10 standard. Through submittals on June 16, 1993, December 
9, 1993, September 8, 1994, and November 17, 1994, the State of Indiana 
submitted the emission control regulations, emissions inventories, 
attainment demonstrations, and other plan elements needed to comply 
with the SIP requirements for PM10. EPA approved Indiana's 
PM10 SIP on June 15, 1995, at 60 FR 31412.
2. Section 110(a) Requirements
    On December 7, 2007, September 19, 2008, March 23, 2011, and April 
7, 2011, Indiana made submittals addressing ``infrastructure SIP'' 
elements required by section 110(a)(2) of the CAA for the 1997 annual 
PM2.5 standard and 1997 8-hour ozone standard. EPA published 
proposed rulemaking on these submittals on April 28, 2011, at 76 FR 
23757, and finalized that rulemaking on July 13, 2011, at 76 FR 41075, 
approving Indiana's infrastructure SIP for these air quality standards. 
The requirements of section 110(a)(2), however, are statewide 
requirements that are not linked to the PM2.5 nonattainment 
status of Lake and Porter Counties.
    EPA finds that section 110 requirements not linked to an area's 
nonattainment status are not applicable for purposes of redesignation. 
See the Reading, Pennsylvania proposed and final rulemakings (October 
10, 1996, at 61 FR 53174-53176, and May 7, 1997, at 62 FR 24826), the 
Cleveland-Akron-Loraine, Ohio final rulemaking (May 7, 1996, at 61 FR 
20458), and the Tampa, Florida final rulemaking (December 7, 1995, at 
60 FR 62748). Therefore, these section 110(a)(2) SIP elements, which 
are unrelated to an area's attainment status, are not applicable 
requirements for purposes of review of the State's PM2.5 
redesignation request.
3. Emission Inventories
    Section 172(c)(3) of the CAA calls for the State to provide a 
complete, accurate, and comprehensive emissions inventory of source 
emissions. In today's action EPA proposes to approve Indiana's 2005 
emissions inventories as meeting this requirement. These emissions 
inventories are addressed in sections V.C and VII below, and are 
documented in appendices B through G of Indiana's May 26, 2011, 
submittal. See the EPA digital docket for this proposed rule, https://www.regulations.gov, which includes a digital copy of Indiana's May 26, 
2011, submittal.
    The basis for EPA's proposed approval of the emissions inventories 
is set forth in the discussions of emission inventory development 
techniques and sources of input data used to determine the emissions 
inventories in section V.C.2 below and in an additional discussion of 
the 2005 base year emissions inventories for Lake and Porter Counties 
in section VII of this proposed rule.
4. Other Nonattainment Area Requirements
    EPA is proposing to determine that, if it issues final approval of 
the emission inventories discussed below under CAA section 172(c)(3), 
the Indiana SIP will meet the SIP requirements for Lake and Porter 
Counties applicable for purposes of redesignation under part D of the 
CAA. Subpart 1 of part D, sections 172 to 176 of the CAA, set forth the 
nonattainment plan requirements applicable to PM2.5 
nonattainment areas.
    Under section 172, states with nonattainment areas must submit 
plans providing for timely attainment and meeting a variety of other 
requirements. However, pursuant to 40 CFR 51.1004(c), EPA's November 
27, 2009, determination that the Greater Chicago nonattainment area is 
attaining the 1997 PM2.5 annual standard suspended Indiana's 
obligation to submit plans meeting most of the CAA attainment planning 
requirements that would otherwise apply. Specifically, the 
determination of attainment suspended Indiana's obligation to submit a 
PM2.5 attainment demonstration, and requirements to provide 
for Reasonable Further Progress (RFP) toward attainment, Reasonably 
Available Control Measures (RACM), and contingency measures under 
section 172(c)(9) of the CAA.
    The General Preamble for Implementation of Title I (57 FR 13498, 
April 16, 1992) also discusses the evaluation of these requirements in 
the context of EPA's consideration of a redesignation request. The 
General Preamble sets forth EPA's view of applicable requirements for 
purposes of evaluating redesignation requests when an area is attaining 
the standard.
    Because attainment has been reached, no additional measures are 
needed to provide for attainment, and section 172(c)(1) requirements 
for an attainment demonstration and RACM are no longer considered to be 
applicable for purposes of redesignation, as long as the area continues 
to attain the standard through final EPA approval of the State's 
redesignation request. See also 40 CFR 51.1004(c). The RFP requirement 
under section 172(c)(2) and contingency measures requirement under 
section 172(c)(9) are similarly not relevant for purposes of 
redesignation since EPA has determined that the area has attained the 
1997 PM2.5 annual standard.
    Section 172(c)(4) of the CAA requires the identification and 
quantification of allowable emissions for major new and

[[Page 59606]]

modified stationary sources in an area, and section 172(c)(5) requires 
source permits for the construction and operation of new and modified 
major stationary sources anywhere in the nonattainment area. EPA has 
determined that, since Prevention of Significant Deterioration (PSD) 
requirements will apply after redesignation, areas being redesignated 
need not comply with the requirement that a nonattainment area New 
Source Review (NSR) program be approved prior to redesignation, 
provided that the area demonstrates maintenance of the NAAQS without 
part D NSR. The 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.''
    Indiana has demonstrated that emissions will remain at or below 
attainment levels throughout the maintenance period without part D NSR 
in effect for Lake and Porter Counties. Therefore, the State need not 
have a fully approved part D NSR program prior to the approval of 
Indiana's redesignation request for Lake and Porter Counties. The 
State's PSD program will become effective in Lake and Porter Counties 
upon redesignation of these Counties to attainment of the 1997 annual 
PM2.5 standard. See rulemakings for Detroit, Michigan (March 
7, 1995, at 60 FR 12467-12468); Cleveland-Akron-Lorain, Ohio (May 7, 
1996, at 61 FR 20458, 20469-20470); Louisville, Kentucky (October 23, 
2001; at 66 FR 53665); and Grand Rapids, Michigan (June 21, 1996, at 61 
FR 31834-31837).
    Section 172(c)(6) of the CAA requires the SIP to contain control 
measures necessary to provide for attainment of the standard. Because 
attainment of the standard in the Greater Chicago nonattainment area 
has been reached, no additional measures are needed to provide for 
attainment.
    Section 172(c)(7) requires the SIP to meet the applicable 
provisions of section 110(a)(2) of the CAA. As noted above, we find 
that the Indiana SIP meets the requirements of section 110(a)(2) 
applicable for purposes of redesignation.
    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 
in the SIPs. EPA approved Indiana's general and transportation 
conformity SIPs on January 14, 1998, at 63 FR 2146, and on August 17, 
2010, at 75 FR 50730, respectively. Indiana has submitted on-road motor 
vehicle budgets for Lake and Porter Counties for 2016 and 2025. The 
area must use the MVEBs from the maintenance plan in any conformity 
determination that is effective on or after the effective date of EPA's 
maintenance plan approval.
    No other SIP provisions relevant to Lake and Porter Counties are 
currently disapproved, conditionally approved, or partially approved.

C. Are the PM2.5 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) requires the State to demonstrate that 
the improvement in air quality is due to permanent and enforceable 
emission reductions.
1. Permanent and Enforceable Emission Controls
    The following is a discussion of permanent and enforceable emission 
control measures that have been implemented in Lake and Porter 
Counties, in the Greater Chicago nonattainment area, and in upwind 
areas (resulting in lower pollutant transport into the Greater Chicago 
nonattainment area).
a. Federal Emission Control Measures
    Reductions in PM2.5 precursor emissions have occurred 
statewide and in upwind areas as a result of the following Federal 
emission control measures. Most of these Federal emission control 
measures will result in additional emission reductions in the future.
    Tier 2 Emission Standards for Vehicles and Gasoline Sulfur 
Standards. These emission control requirements result in lower Volatile 
Organic Compounds (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 sport utility vehicles, 86 percent; and, larger sport 
utility vehicles, vans, and heavier trucks, 69 to 95 percent. Some of 
the emissions reductions resulting from new vehicle standards occurred 
during the 2008-2010 attainment period; however, additional reductions 
will continue to occur throughout the maintenance period as the fleet 
of older vehicles turns over. The Tier 2 standards also reduced the 
sulfur content of gasoline to 30 parts per million (ppm) beginning in 
January 2006. Most gasoline sold in Indiana prior to January 2006 had a 
sulfur content of approximately 500 ppm. Sulfur occurs naturally in 
gasoline, but interferes with the operation of catalytic converters. 
Lowering the sulfur content of gasoline improves the emission reduction 
resulting from the use of catalytic converters and results in 
significantly lowered NOX emissions. In addition, lowering 
the sulfur content of gasoline also reduces direct emissions of 
sulfates (direct PM2.5) from vehicles.
    Heavy-Duty Diesel Engine Rule. This rule, which EPA issued in July 
2000, limited the sulfur content of diesel fuel and went into effect in 
2004. A second phase of implementation took effect in 2007 and resulted 
in reduced PM2.5 emissions from heavy-duty highway diesel 
engines and further reduced the highway diesel fuel sulfur content to 
15 ppm. The full implementation of this rule is estimated to achieve a 
90 percent reduction in direct PM2.5 emissions (including 
direct emissions of sulfates) and a 95 percent reduction in 
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 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 emissions reduction and the level of its impact on 
PM2.5 concentrations.
    Nonroad Diesel Engine Standards. In May 2004, EPA promulgated a 
rule to establish emission standards for large nonroad diesel engines, 
such as those used in construction, agriculture, or mining operations 
(the engine emission standards are phased in between 2008 and 2014) and 
to regulate the sulfur content in nonroad diesel fuel. This rule 
reduced the allowable sulfur content in nonroad diesel fuel by over 99 
percent. Prior to 2006, nonroad diesel fuel averaged approximately 
3,400 ppm in sulfur content. This rule limited nonroad diesel sulfur 
content to 500 ppm by 2006, with a further reduction to 15 ppm by 2010. 
The combined engines standards and fuel sulfur

[[Page 59607]]

content limits reduce NOX and PM2.5 emissions 
(including direct emissions of sulfates) from large nonroad diesel 
engines by over 90 percent compared to pre-control nonroad engines 
using the higher sulfur content diesel fuel. This rule achieved all of 
the reductions in fuel sulfur content by 2010. Some emissions 
reductions from the new engine emission standards were realized over 
the 2008-2010 time period; although most of the reductions will occur 
during the maintenance period as the fleet of older nonroad diesel 
engines turns over.
    Nonroad Spark-Ignition Engines and Recreational Engine Standards. 
In November 2002, EPA promulgated emission standards for groups of 
previously unregulated nonroad 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, including off-highway motorcycles, all-terrain vehicles, and 
snowmobiles; and, recreational marine diesel engines. Emission 
standards for large spark-ignition engines were implemented in two 
phases (tiers), with Tier 1 starting in 2004 and Tier 2 starting in 
2007. Recreational vehicle emission standards are being phased in from 
2006 through 2012. Marine diesel engine standards were phased in from 
2004 through 2009. With full implementation of all of these standards, 
an overall 72 percent reduction in VOC, and 80 percent reduction in 
NOX emissions are expected by 2020. A significant portion of 
these emission reductions occurred by 2008, the year Indiana has 
selected to be the attainment baseline year in the demonstration of 
maintenance discussed later in this proposed rule. Additional emission 
reductions will occur in Lake and Porter Counties, statewide in Indiana 
and Illinois, and in upwind areas during the maintenance period for 
Lake and Porter Counties.
b. Control Measures in Upwind Areas
    Given the significance of sulfates and nitrates as components of 
PM2.5 in the Greater Chicago nonattainment area, the area's 
PM2.5 air quality in this area is strongly affected by 
regulation of SO2 and NOX emissions from power 
plants in this nonattainment area and in upwind areas. The following 
considers the emission control measures that have affected these 
emissions.
    NOX SIP Call. On October 27, 1998, at 63 FR 57356, EPA issued a 
NOX SIP call requiring the District of Columbia and 22 
states to reduce emissions of NOX. Affected states were 
required to comply with Phase I of the SIP call beginning in 2004, and 
with Phase II beginning in 2007. The NOX SIP call 
established state-specific NOX emission caps, assuming 
possible NOX emission control levels for various source 
types within EGUs and using EGU-specific historical operating data. 
States, including Indiana, have adopted NOX emission control 
regulations for EGUs (and for other major stationary NOX 
sources) to achieve the state-specific NOX emission caps. 
These NOX emission caps are supported by periodic reporting 
of state NOX emissions to the EPA. The reduction in 
NOX emissions has resulted in lower concentrations of 
transported NOX and PM2.5 into the Greater 
Chicago PM2.5 nonattainment area. Emission reductions 
resulting from state regulations developed in response to the 
NOX SIP call are permanent and enforceable.
    CAIR. See the detailed discussion of CAIR in section III of this 
proposed rule.
    CSAPR. See the discussion of CSAPR in section III of this proposed 
rule.
    All of the emission reduction requirements discussed above have led 
to (or will lead to) substantial emission reductions and have been 
shown by Indiana and EPA (in analyses supporting CAIR and CSAPR) to be 
the main cause of the emission reductions discussed below.
2. Emission Reductions
    To demonstrate that significant emission reductions have resulted 
in attainment, Indiana compared the NOX, SO2, and 
primary PM2.5 emissions for 2002 and 2005 with those of 
2008. The emissions inventories for 2008 represent a year in which the 
area was attaining the 1997 annual PM2.5 standard.
    The 2002, 2005, and 2008 point source emissions were obtained from 
Indiana's source facility emissions reporting program for Lake and 
Porter Counties. Point source emissions for Illinois' portion of the 
Greater Chicago nonattainment area \4\ were derived from 2002 and 2008 
point source emissions documented in Illinois' ``Maintenance Plan for 
the Chicago Nonattainment Area for the 1997 PM2.5 National 
Ambient Air Quality Standard'' (Illinois' PM2.5 maintenance 
plan) prepared in September 2010. The 2005 point source emissions for 
Illinois' portion of the PM2.5 nonattainment area were 
interpolated using Illinois' 2002 and 2008 point source emission 
estimates. EPA's Clean Air Market's Acid Rain database (https://camddataandmaps.epa.gov/gdm/) was also used to estimate SO2 
and NOX emissions for certain point sources.
---------------------------------------------------------------------------

    \4\ Emissions for the Illinois portion of the PM2.5 
nonattainment area must be considered along with the emissions for 
Lake and Porter Counties to demonstrate the emission reductions 
resulting in attainment of the PM2.5 standard and to 
demonstrate maintenance of the PM2.5 standard for the 
entire bi-state PM2.5 nonattainment area.
---------------------------------------------------------------------------

    On-road mobile source emissions were calculated using EPA's mobile 
source emission factor model, MOBILE6.2, and other mobile source input 
data, including vehicle age and type distributions and speeds, derived 
using Northwest Indiana Regional Planning Commission's (NIRPC's) travel 
demand model.
    Area source emissions for Lake and Porter Counties for 2002 and 
2005 were taken from Indiana's 2002 and 2005 periodic emissions 
inventories.\5\ The 2005 periodic emission inventory area source 
emissions were extrapolated to 2008. Source growth factors were 
supplied for area and nonroad mobile sources by the Lake Michigan Air 
Directors Consortium (LADCO). Area source emissions for the Illinois 
portion of the Greater Chicago nonattainment area were obtained from 
the 1997 annual PM2.5 maintenance plan submitted by Illinois 
on October 15, 2010.
---------------------------------------------------------------------------

    \5\ Periodic emission inventories are developed by states every 
three years and reported to EPA. These periodic emission inventories 
are required by the Federal Consolidated Emissions Reporting Rule, 
codified at 40 CFR Subpart A. EPA revised these and other emission 
reporting requirements in a final rule published on December 17, 
2008, at 73 FR 76539.
---------------------------------------------------------------------------

    Nonroad mobile source emissions were extracted or extrapolated from 
nonroad mobile source emissions reported in EPA's 2005 National 
Emissions Inventory (NEI). Contractors were employed by LADCO to 
estimate emissions for commercial marine vessels and railroads.
    Pre-2008 EGU emissions were derived from EPA's Clean Air Market's 
Acid Rain database. These emissions reflect Indiana's SO2 
and NOX emission budgets resulting from EPA's NOX 
SIP call. The 2008 emissions from EGUs reflect Indiana's emission caps 
under EPA's CAIR.
    The 2002 and 2005 base year NOX, SO2, and 
primary PM2.5 emission totals by source sector are given in 
table 2.

[[Page 59608]]



                Table 2--Lake and Porter Counties 2002 and 2005 Emission Totals by Source Sector
                                                 [Tons per year]
----------------------------------------------------------------------------------------------------------------
                                                                      On-road        Off-road
            Pollutant                  Point           Area           mobile          mobile          Totals
----------------------------------------------------------------------------------------------------------------
                                  2002 Lake and Porter Counties Emission Totals
----------------------------------------------------------------------------------------------------------------
NOX.............................       60,808.11        2,626.91       30,397.97       12,347.30      106,180.29
SO2.............................       59,263.34         4364.85          264.64        1,106.59       64,999.42
Primary PM2.5...................        7,313.70        4,404.91          562.64          685.43       12,966.68
----------------------------------------------------------------------------------------------------------------
                                  2005 Lake and Porter Counties Emission Totals
----------------------------------------------------------------------------------------------------------------
NOX.............................       41,948.57        2,236.89       14,095.55        8,145.64       66,426.65
SO2.............................       48,139.53          697.87          146.44          892.93       49,876.77
Primary PM2.5...................        6,451.40           23.65          229.39          447.87        7,152.31
----------------------------------------------------------------------------------------------------------------

    The 2008 emissions totals for SO2, NOX, and 
primary PM2.5 for Lake and Porter Counties are summarized in 
table 3. These emissions establish attainment year emissions levels for 
Lake and Porter Counties.

                     Table 3--Lake and Porter Counties 2008 Emission Totals by Source Sector
                                                 [Tons per year]
----------------------------------------------------------------------------------------------------------------
                                                                      On-road        Off-road
            Pollutant                  Point           Area           mobile          mobile          Totals
----------------------------------------------------------------------------------------------------------------
NOX.............................       39,945.76        2,264.46       10,703.81        6,667.71       59,581.74
SO2.............................       54,916.02          703.25          103.08          476.33       56,198.68
Primary PM2.5...................        6,676.32           23.66          187.10          363.91        7,250.93
----------------------------------------------------------------------------------------------------------------

    The emissions totals in tables 2 and 3 for NOX show 
significant emission reductions occurred in Lake and Porter Counties 
between 2002 and 2005, and NOX emissions continued this 
downward trend between 2005 and 2008. The emissions for SO2 
and primary PM2.5 also show significant reductions between 
2002 and 2008, but do not show such a downward trend between 2005 and 
2008. We believe that the significant downward trends in NOX 
emissions more significantly contributed to the improved 
PM2.5 air quality observed between 2002/2005 and 2008 than 
the smaller reductions in SO2 and primary PM2.5 
emissions.
    Table 4 presents the NOX, SO2, and primary 
PM2.5, emission totals for the entire Greater Chicago 
nonattainment area for 2002, 2005, and 2008. This table provides a 
compelling demonstration of the reduction in PM2.5 and 
PM2.5 precursor emissions between 2002, when the area was 
violating the 1997 annual PM2.5 standard, and 2005, when the 
area was in attainment of the 1997 annual PM2.5 standard.

        Table 4--Chicago-Gary-Lake County, IL-IN Nonattainment Area 2002, 2005, and 2008 Emission Totals
                                                 [Tons per year]
----------------------------------------------------------------------------------------------------------------
                              Year                                      NOX             SO2        Primary PM2.5
----------------------------------------------------------------------------------------------------------------
2002............................................................      447,601.29      197,480.42       32,069.68
2005............................................................      346,671.15      164,171.77       25,962.31
2008............................................................      278,649.74      152,367.68       25,767.93
----------------------------------------------------------------------------------------------------------------

    IDEM finds that the emission reductions in Lake and Porter Counties 
and in the Illinois portion of the Greater Chicago nonattainment area 
which are permanent and enforceable were primarily responsible for the 
area's attainment of the 1997 annual PM2.5 standard, but 
acknowledges that emission reductions from throughout Indiana and 
Illinois and from other upwind states also contributed to the area's 
attainment. We agree with this conclusion.
    In addition to the local and PM2.5 nonattainment area 
emission reductions, we believe that regional NOX and 
SO2 emission reductions resulting from the implementation of 
the Acid Rain Program (ARP) (see 40 CFR parts 72 through 78), the 
NOX SIP call, and CAIR have significantly contributed to the 
PM2.5 air quality improvement in the Greater Chicago 
nonattainment area. To assess the change in regional emissions from 
states believed to significantly contribute to annual PM2.5 
concentrations in the Greater Chicago nonattainment area, we have 
considered statewide emissions for 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 pollutant transport 
into Greater Chicago nonattainment area), as documented in EPA's 
proposed rule for CSAPR (August 2, 2010, 75 FR 45210) and in technical 
analyses supporting CSAPR and its proposed rule (
                    

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