2011-24376. 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.

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 (PM_2.5) 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 PM_2.5 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 (NO_X) and PM_2.5 Motor Vehicle Emission Budgets (MVEBs) for Lake and Porter Counties, as well as the 2005 PM_2.5-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:

• http://http://www.regulations.gov: Follow the on-line instructions for submitting comments.
• E-mail: [e-mail].
• Fax: [phone].
• 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 http://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 http://www.regulations.gov or e-mail. The http://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 http://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 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 http://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 http://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] 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], or [e-mail].

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 PM_2.5 Redesignation Request and Maintenance Plan

IV. What are the criteria for redesignation to attainment?

V. Review of the State's PM_2.5 Redesignation Request and Basis for EPA's Proposed Actions

A. Has the greater Chicago nonattainment area attained the 1997 annual PM_2.5 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 PM_2.5 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 PM_2.5 maintenance plan pursuant to Section 175A of the CAA for Lake and Porter Counties?

VI. Has the State adopted acceptable MVEBs for the PM_2.5 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 PM_2.5 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 PM_2.5 redesignation request, as discussed below. In a separate proposed rule, EPA will address an Illinois PM_2.5 redesignation request for the Illinois portion of the Greater Chicago nonattainment area.

EPA is proposing to approve Indiana's 1997 annual PM_2.5 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 PM_2.5 redesignation request and maintenance plan later in this proposed rule.

EPA is proposing to approve 2005 emissions inventories for primary PM_2.5,^[1] NO_X, and sulfur dioxide (SO₂),^[2] documented in Indiana's May 26, 2011, PM_2.5 redesignation request submittal, as satisfying the requirement in section 172(c)(3) of the CAA for a comprehensive, current, and accurate emission inventory.

EPA is proposing to find that Indiana meets the requirements for redesignation of Lake and Porter Counties to attainment of the 1997 annual PM_2.5 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 PM_2.5 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 proposing to determine that the emission reductions that led to attainment of the 1997 annual PM_2.5 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 PM_2.5 NAAQS.

Finally, EPA is proposing to approve 2025 primary PM_2.5 and NO_X MVEBs for Lake and Porter Counties documented in Indiana's PM_2.5 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 PM_2.5 were promulgated on July 18, 1997, at 62 FR 38652. EPA promulgated an annual standard at a level of 15 micrograms per cubic meter (μg/m³) of ambient air, based on a three-year average of the annual mean PM_2.5 concentrations at each monitoring site (1997 annual PM_2.5 standard). In the same rulemaking, EPA promulgated a 24-hour PM_2.5 standard, at 65 μg/m³, based on a three-year average of the annual 98th percentile of 24-hour PM_2.5 concentrations at each monitoring site. On October 17, 2006, at 71 FR 61144, EPA retained the annual PM_2.5 standard at 15 μg/m³ (2006 annual PM_2.5 standard), but revised the 24-hour standard to 35 μg/m³, based again on the three-year average of the annual 98th percentile of the 24-hour PM_2.5 concentrations.

On January 5, 2005, at 70 FR 944, EPA published air quality area designations and classifications for the 1997 annual PM_2.5 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 PM_2.5 standard.

In response to legal challenges of the 2006 annual PM_2.5 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 PM_2.5 standards are essentially identical, attainment of the 1997 annual PM_2.5 standard also indicates attainment of the remanded 2006 annual standard. Since the Greater Chicago area is designated as nonattainment only for the 1997 annual PM_2.5 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 PM_2.5) 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 NO_X from power plants, mobile sources, and other combustion sources.

Given the significance of sulfates and nitrates in the formation of PM_2.5 in and transport of PM_2.5 into the Greater Chicago nonattainment area, the regulation of SO₂ and NO_X 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 NO_X 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 PM_2.5 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 NO_X 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 NO_X 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 NO_X 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 NO_X and SO₂ emissions to levels well below the levels that led to attainment of the 1997 annual PM_2.5 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 PM _2.5 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 PM_2.5 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, PM_2.5 redesignation request to show that the Greater Chicago nonattainment area continued to attain the 1997 annual PM_2.5 standard through 2008.

In addition to showing that this area has attained the 1997 annual PM_2.5 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 PM_2.5 standard. The redesignation request includes a maintenance plan for Lake and Porter Counties demonstrating maintenance of the 1997 annual PM_2.5 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 PM_2.5 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 PM_2.5 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 PM_2.5 maintenance demonstration, which must, at a minimum, demonstrate attainment of the 1997 annual PM_2.5 standard for at least ten years after EPA approves the State's PM_2.5 redesignation request. See section 175A(a) of the CAA. This necessitated a revision of the PM_2.5 maintenance plan by the State to extend the maintenance demonstration to a later endpoint.

On May 26, 2011, IDEM submitted a revised PM_2.5 maintenance plan to EPA demonstrating maintenance of the 1997 annual PM_2.5 in Lake and Porter Counties through 2025. In this submittal, the State included additional air quality data showing continued attainment of the 1997 annual PM_2.5 standard in the Greater Chicago nonattainment area during 2008-2010.

The State held a public hearing on the PM_2.5 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 PM_2.5 redesignation request and final PM_2.5 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 PM_2.5 and NO_X MVEBs, which IDEM requests EPA to approve and find adequate for use in transportation conformity determinations and demonstrations.^[3]

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 PM_2.5 Redesignation Request and Basis for EPA's Proposed Actions

A. Has the Greater Chicago nonattainment area attained the 1997 annual PM _2.5 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 PM_2.5 standard. This determination was based on complete, quality-assured air monitoring data for 2006-2008.

The April 3, 2008, IDEM PM_2.5 redesignation request presents PM_2.5 data for the period of 2005-2007, and the May 26, 2011, IDEM submittal presents PM_2.5 data for the period of 2008-2010. These quality-assured data show that the Greater Chicago nonattainment area attained the 1997 annual PM_2.5 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 PM_2.5 annual air quality data for the area for the period of 2008-2010.

Table 1—PM_2.5 Annual Average Concentrations for the Greater Chicago Nonattainment Area

(in μg/m³)

County	Monitoring site AQS site number	2008	2009	2010	3-Year average
Indiana Monitoring Sites
Lake	Franklin School, 180890006	11.95	11.34	12.48	11.9
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 School, 180892010	12.42	10.80	11.90	11.7
Lake	Gary-Madison Street, 180890031	12.27	12.12	12.90	12.4
Porter	Ogden Dunes, 181270024	10.89	11.29	11.56	11.2
Illinois Monitoring Sites
Cook	Chicago-Washington High School, 170310022	12.54	11.62	14.04	12.7
Cook	Chicago-Southeast Police Station, 170310050	11.80	10.99	12.47	11.8
Cook	Chicago-Mayfair Pump Station, 170310052	12.18	12.69	12.57	12.5
Cook	Chicago-Springfield Pump Station, 170310057	12.03	11.33	1 12.03	1 11.8
Cook	Chicago-Commonwealth Edison Maintenance Building, 170310076	11.89	11.12	12.25	11.8
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 PM_2.5 monitors in the Greater Chicago nonattainment area have recorded PM_2.5 concentrations attaining the 1997 annual PM_2.5 standard during 2008-2010. These annual average PM_2.5 concentrations are based on PM_2.5 monitoring data that have been quality assured and stored in EPA's Air Quality System (AQS) database.

Further consideration of annual PM_2.5 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 PM_2.5 standard), a year of PM_2.5 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 PM_2.5 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 PM_2.5 standard. For the Hammond-Purdue site, complete 2006-2008 data show annual PM_2.5 concentrations of 12.67, 13.8, and 11.66 µg/m³, with an average of 12.7 µg/m³ 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 PM_2.5 concentrations of 15.18, 12.03, and 11.33 µg/m³, with an average of 12.85 µg/m³ 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 PM_2.5 standard (See table 1). EPA, thus, concludes that the Hammond-Purdue and Chicago-Springfield Pump Station sites monitored attainment of the 1997 annual PM_2.5 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 PM_2.5 concentrations suggest that the partial evidence of PM_2.5 concentrations at the Hammond-Purdue and Chicago-Springfield Pump Station sites are indeed indicative that the 1997 annual PM_2.5 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 PM_2.5 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 PM_2.5 concentrations for the Cicero monitoring site and our conclusion that, although the PM_2.5 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 PM_2.5 standard in 2008 and throughout 2006-2008.

EPA has conducted PM_2.5 data substitution tests for the 2009 PM_2.5 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 PM_2.5 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 PM_2.5 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 PM_2.5concentrations, such as those for the Blue Island monitoring site, suggest that the partial evidence of PM_2.5 concentrations at the Cicero monitoring site are indeed indicative that the 1997 annual PM_2.5 standard is being attained at this site. See PM_2.5-related data links and spreadsheets with data for this monitoring site at: http://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 PM_2.5 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 PM_2.5 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 PM_2.5 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 PM_2.5 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, http://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 PM_2.5 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 PM_2.5 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 PM_2.5 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 PM_2.5 annual standard.

Section 172(c)(4) of the CAA requires the identification and quantification of allowable emissions for major new and modified stationary sources in an area, and section 172(c)(5) requires source permits for the construction and operation of new and modified major stationary sources 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 PM_2.5 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 PM _2.5 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 PM_2.5 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), NO_X, 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 NO_X 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 NO_X emissions. In addition, lowering the sulfur content of gasoline also reduces direct emissions of sulfates (direct PM_2.5) 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 PM_2.5 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 PM_2.5 emissions (including direct emissions of sulfates) and a 95 percent reduction in NO_X 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 PM_2.5 concentrations; however, EPA has not estimated the level of this emissions reduction and the level of its impact on PM_2.5 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 content limits reduce NO_X and PM_2.5 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 NO_X 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 PM_2.5 in the Greater Chicago nonattainment area, the area's PM_2.5 air quality in this area is strongly affected by regulation of SO₂ and NO_X emissions from power plants in this nonattainment area and in upwind areas. The following considers the emission control measures that have affected these emissions.

NO_XSIP Call. On October 27, 1998, at 63 FR 57356, EPA issued a NO_X SIP call requiring the District of Columbia and 22 states to reduce emissions of NO_X. Affected states were required to comply with Phase I of the SIP call beginning in 2004, and with Phase II beginning in 2007. The NO_X SIP call established state-specific NO_X emission caps, assuming possible NO_X emission control levels for various source types within EGUs and using EGU-specific historical operating data. States, including Indiana, have adopted NO_X emission control regulations for EGUs (and for other major stationary NO_X sources) to achieve the state-specific NO_X emission caps. These NO_X emission caps are supported by periodic reporting of state NO_X emissions to the EPA. The reduction in NO_X emissions has resulted in lower concentrations of transported NO_X and PM_2.5 into the Greater Chicago PM_2.5 nonattainment area. Emission reductions resulting from state regulations developed in response to the NO_X 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 NO_X, SO₂, and primary PM_2.5 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 PM_2.5 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 PM_2.5 National Ambient Air Quality Standard” (Illinois' PM_2.5 maintenance plan) prepared in September 2010. The 2005 point source emissions for Illinois' portion of the PM_2.5 nonattainment area were interpolated using Illinois' 2002 and 2008 point source emission estimates. EPA's Clean Air Market's Acid Rain database (http://camddataandmaps.epa.gov/​gdm/​) was also used to estimate SO₂ and NO_X emissions for certain point sources.

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 PM_2.5 maintenance plan submitted by Illinois on October 15, 2010.

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 NO_X emission budgets resulting from EPA's NO_X SIP call. The 2008 emissions from EGUs reflect Indiana's emission caps under EPA's CAIR.

The 2002 and 2005 base year NO_X, SO₂, and primary PM_2.5 emission totals by source sector are given in table 2.

Table 2—Lake and Porter Counties 2002 and 2005 Emission Totals by Source Sector

[Tons per year]

Pollutant	Point	Area	On-road mobile	Off-road 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, NO_X, and primary PM_2.5 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]

Pollutant	Point	Area	On-road mobile	Off-road 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 NO_X show significant emission reductions occurred in Lake and Porter Counties between 2002 and 2005, and NO_X emissions continued this downward trend between 2005 and 2008. The emissions for SO₂ and primary PM_2.5 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 NO_X emissions more significantly contributed to the improved PM_2.5 air quality observed between 2002/2005 and 2008 than the smaller reductions in SO₂ and primary PM_2.5 emissions.

Table 4 presents the NO_X, SO₂, and primary PM_2.5, emission totals for the entire Greater Chicago nonattainment area for 2002, 2005, and 2008. This table provides a compelling demonstration of the reduction in PM_2.5 and PM_2.5 precursor emissions between 2002, when the area was violating the 1997 annual PM_2.5 standard, and 2005, when the area was in attainment of the 1997 annual PM_2.5 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 PM_2.5 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 PM_2.5 nonattainment area emission reductions, we believe that regional NO_X and SO₂ emission reductions resulting from the implementation of the Acid Rain Program (ARP) (see 40 CFR parts 72 through 78), the NO_X SIP call, and CAIR have significantly contributed to the PM_2.5 air quality improvement in the Greater Chicago nonattainment area. To assess the change in regional emissions from states believed to significantly contribute to annual PM_2.5 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 PM_2.5 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 (http://www.epa.gov/​airtransport/​techinfo.html). Table 5 lists the statewide total NO_X and SO₂ emissions for EGUs for the selected States.

Table 5—Statewide EGU Emissions for 2002 and 2008

[Tons per year]

State	NOX			SO2
	2002	2008	Percent reduction	2002	2008	Percent 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	191,256	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 5, the implementation of CAIR resulted in significant reductions in regional statewide NO_X and SO₂ emissions from EGUs in the states EPA finds are contributing significantly to the annual PM_2.5 concentrations in the Greater Chicago nonattainment area. CAIR requirements address emissions through 2011. CSAPR in turn requires similar or greater emission reductions in the nine states identified in table 5 starting in 2012. The upwind emission reduction requirements that contributed to the air quality improvements in the Greater Chicago nonattainment, thus, can be considered to be permanent and enforceable.

In summary, the local emissions data provided by the State of Indiana support the conclusion that significant permanent and enforceable NO_X and SO₂ emission reductions have occurred in the Greater Chicago nonattainment area. For the reasons set forth above, we also conclude that significant permanent and enforceable emission reductions have occurred in regional emissions, thus bolstering the observed improvement in annual PM_2.5 concentrations in the Greater Chicago nonattainment area. We thus believe that Indiana's redesignation request meets the requirement of section 107(d)(3)(E)(iii) of the CAA.

D. Does Indiana have a fully approvable PM_2.5 maintenance plan pursuant to section 175A of the CAA for Lake and Porter Counties?

Sections 107(d)(3)(E)(iv) and 175A of the CAA require that the State demonstrate that the area to be redesignated will continue to meet the PM_2.5 NAAQS for at least a ten-year maintenance period after EPA's approval of the redesignation. Indiana's maintenance plan includes emission inventories that demonstrate that emissions of SO₂, NO_X, and primary PM_2.5 in the Greater Chicago nonattainment area will remain at or below the attainment year levels for the ten-year period after EPA takes action to approve Indiana's redesignation request.

As part of Indiana's redesignation request for Lake and Porter Counties, the State included projected NO_X, SO₂, and primary PM_2.5 emissions inventories for the PM_2.5 nonattainment area for 2015, 2020, and 2025. These projected inventories were compared to the 2008 attainment year emissions inventories to demonstrate maintenance of the 1997 annual PM_2.5 standard in the Greater Chicago nonattainment area. The on-road mobile source emission components of the 2015 (projected to 2016) and 2025 emissions inventories were also used to establish MVEBs for Lake and Porter Counties to be used in transportation conformity demonstrations. See the discussion of the MVEBs below in section VI of this proposed rule.

For each of the applicable pollutants and projection years, Indiana prepared emission estimates for four types of anthropogenic sources: point sources; area sources; on-road mobile sources; and, nonroad mobile sources. Biogenic emissions were assumed to remain constant, and were not considered in the maintenance demonstration analysis.

The projected 2015, 2020, and 2025 emissions were estimated by IDEM, with assistance from LADCO, the Illinois Environmental Protection Agency, and NIRPC. Table 6 lists the projected NO_X, SO₂, and primary PM_2.5 emissions along with the 2008 emissions by source sector for Lake and Porter Counties.

Table 6—Lake and Porter Counties 2008, 2015, 2020, and 2025 Emissions by Source Sector

[Tons per year]

Pollutant	Point	Area	On-road mobile	Off-road mobile	Totals
2008 Lake and Porter Counties Emissions 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
2015 Lake and Porter Counties Emissions Totals
NOX	28,883.26	2,226.21	5,723.67	4,962.17	41,795.31
SO2	42,394.24	682.86	66.23	267.22	43,410.55
Primary PM2.5	6,650.33	22.70	136.61	248.01	7,057.65
2020 Lake and Porter Counties Emissions Totals
NOX	27,832.65	2,187.09	3,004.68	4,057.84	37,082.26
SO2	38,493.19	664.67	72.76	215.27	39,445.89
Primary PM2.5	6,566.86	21.97	114.32	185.11	6,888.26
2025 Lake and Porter Counties Emissions Totals
NOX	26,980.09	2,148.80	2,534.95	3,349.95	35,013.79
SO2	35,888.27	647.07	76.51	175.39	36,787.24
Primary PM2.5	6,484.75	21.29	115.39	140.67	6,762.10

Table 7 lists the projected emissions for the Greater Chicago nonattainment area along with the 2008 emissions for this area.

Table 7—Chicago-Gary-Lake County, IL-IN PM_2.5 Nonattainment Area Projected Emissions Totals

[Tons per year]

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

Comparison of the 2008 and projected 2015, 2020, and 2025 emissions demonstrates that future emissions through 2025 show that the emissions levels should remain below the 2008 emission levels in Lake and Porter Counties and in the Greater Chicago area. Therefore, the State has demonstrated maintenance of the PM_2.5 standard in this area for a period extending ten years and beyond from the time EPA may be expected to complete rulemaking on the State's PM_2.5 redesignation request for Lake and Porter Counties.

In addition to maintenance of local emissions at or below attainment levels, EPA considered the continued impact of regional emissions levels since we believe that these emissions will contribute significantly to annual PM_2.5 concentrations during the maintenance period. Based on the same states identified in CSAPR as significant contributors of PM_2.5 precursor emissions (see table 5 and its related discussion above), table 8 compares these state's statewide EGU emissions for 2008 (the attainment year), derived from the CAIR emissions database, with the 2012-2013 and 2014 and beyond (2014+) statewide EGU emission budgets established in the preamble to the CSAPR (table VI.D-3, 76 FR 48261). The CSAPR emission budgets listed in table 8 do not include state-specific source variability limits or source set-aside emission limits, otherwise established in CSAPR.

Table 8—Statewide EGU Emissions (2008) and Emission Budgets in the Cross-State Air Pollution Rule

[Tons per year]

State	2008	2012-2013 CSAPR emission budget	2014 and later CSAPR emission budget
NOX
Illinois	119,930	47,872	47,872
Indiana	190,092	109,726	108,424
Iowa	49,023	38,335	37,424
Kentucky	157,903	85,086	77,238
Michigan	107,623	60,193	57,812
Minnesota	60,230	29,572	29,572
Missouri	88,742	52,374	48,717
Ohio	235,049	92,703	87,493
Pennsylvania	183,658	119,986	119,194
Wisconsin	47,794	31,628	30,398
Total	1,240,044	667,475	644,144
SO2
Illinois	257,357	234,889	124,123
Indiana	565,459	285,424	161,111
Iowa	109,293	107,085	75,184
Kentucky	344,356	189,335	106,284
Michigan	326,500	194,537	143,995
Minnesota	71,926	41,981	41,981
Missouri	258,269	207,466	165,941
Ohio	709,444	310,230	137,077
Pennsylvania	831,914	278,651	112,021
Wisconsin	129,693	79,480	40,126
Total	3,604,211	1,929,078	1,107,843

The EGU emissions and emissions budgets listed in table 8 show that CSAPR is expected to result in significantly lower regional EGU emissions after 2008. Therefore, CSAPR is expected to maintain regional EGU emissions below the attainment period levels during the maintenance period for Lake and Porter Counties. These emission reductions are expected to be enforceable and generally permanent on a regional basis.^[6]

The sizeable reductions in SO₂ and NO_X emissions by 2015, 2020, and 2025, relative to those in 2008, shown by comparing emissions in tables 3, 4, 6, and 7 above, are due in significant part to restrictions mandated by EPA to reduce power plant emissions of SO₂ and NO_X in the Eastern United States in order to reduce pollutant transport in this region. To develop the 2015, 2020, and 2025 EGU emission inventories, Indiana used emission projections premised on the implementation of CAIR requirements as an approximation of the emissions levels the States of Indiana and Illinois project to occur following the promulgation of CSAPR. We acknowledge that emissions following implementation of CSAPR may differ somewhat from the emissions that would have occurred under CAIR.

On the other hand, as noted above, EPA's CSAPR achieves substantial regional reductions of SO₂ and NO_X emissions from EGUs. EPA has not made emission estimates for 2020 or 2025 that are premised on the implementation of CSAPR. However, table 8 above shows the emission budgets that EPA established in CSAPR for the relevant states. These emission budgets are significantly lower than the 2008 EGU emissions in each State. CSAPR also addresses EGU emissions in the Greater Chicago nonattainment area. Given the substantial degree of control of the various EGUs in Lake and Porter Counties, and in the Greater Chicago nonattainment area as a whole, both currently and projected into the future, EPA finds Indiana's projection of such emission declines through 2025 to be appropriate forecasts of future emissions. The projected emission reductions for the Greater Chicago nonattainment area, along with the SO₂ and NO_X emission reductions expected to occur in upwind states, demonstrate continued maintenance of the PM_2.5 annual standard in the Greater Chicago nonattainment area.

In conjunction with the projections for dramatic declines in the Greater Chicago nonattainment area emissions of SO₂ and NO_X, Indiana shows that there will also be a decrease in primary PM_2.5 emissions in this area between 2008 and 2025, although the percentage of this emission reduction is relatively small compared to those of SO₂ and NO_X emissions.

Maintenance of the 1997 annual PM_2.5 air quality standard in the Greater Chicago nonattainment area is a function of regional as well as local emissions trends. The regional impacts are dominated by the impacts of SO₂ and NO_X emissions. The previous section (discussing permanent and enforceable emission reductions) showed that CSAPR is expected to provide for substantial SO₂ and NO_X emission reductions through 2014 and beyond, reductions that are expected to be maintained throughout and well beyond the period (through 2020 and 2025) addressed in Indiana's maintenance plan. This lends support to Indiana's projection that regional emission limitations in place will continue to result in low emissions in 2020 and 2025. With CSAPR, the caps on emissions of SO₂ and NO_X from the power sector will ensure against growth in SO₂ and NO_X emissions from these sources, and, in combination with motor vehicle rules and other rules, will assure a continuing decline in SO₂ and NO_X emissions. Therefore, EPA notes that available emissions data indicate that, with the implementation of CSAPR, the Greater Chicago area can be expected to maintain the standard through 2025.

EPA concludes that Indiana's maintenance plan demonstrates maintenance for the period required under section 175A of the CAA, and consideration of the impacts of CSAPR supports this conclusion.

Indiana also presented modeling analysis indicating that the Greater Chicago area will continue to attain the PM_2.5 NAAQS well into the future. This analysis was produced by LADCO, and submitted by Indiana as part of the May 26, 2011, submittal. EPA disagrees with Indiana's contention that this modeling demonstrates attainment in the Greater Chicago area in the absence of CAIR, insofar as the analysis was predicated on 2007 emission levels that already include a set of emission reductions attributable to CAIR. However, EPA contends that the analysis, showing attainment with implementation of a subset of the emission reductions expected from CAIR, supports the conclusion that implementation of the full set of reductions that were expected from CAIR (or a relatively similar set of reductions from CSAPR) will also assure that the standard is maintained.

Indiana's maintenance plan contains additional elements, including a commitment to continue to operate an EPA-approved monitoring network to track ongoing compliance with the NAAQS. Indiana currently operates six ambient PM_2.5 monitors in Lake and Porter Counties. Indiana remains obligated to continue to collect and follow quality assurance procedures for monitoring data in accordance with 40 CFR part 58 and to enter all data into the Air Quality System in accordance with Federal guidelines. Indiana will use these data, supplemented with PM_2.5 monitoring data from the Illinois portion of the Greater Chicago area and any additional information necessary, to verify continued attainment of the standard. Indiana will also continue to develop and submit periodic emission inventories, as required by the Federal Consolidated Emissions Reporting Rule (codified at 40 CFR part 51 subpart A), to track future levels of emissions.

Indiana's maintenance plan also includes contingency measures as required by section 175A(d) of the CAA. The contingency measures are designed to prevent or promptly correct a violation of the NAAQS after redesignation to attainment of the standard. Section 175A of the CAA requires that a maintenance plan include such contingency measures as EPA deems necessary to assure that the State will promptly correct a violation of the NAAQS that occurs after redesignation, including all measures that were in the plan prior to redesignation. Indiana's contingency measures provide that, if a violation occurs, Indiana will implement an “Action Level Response” to evaluate what measures are warranted to address the violation. In particular, IDEM commits to implementing one or more measures from a list of candidate measures given in the plan, or other emission control measures, as needed to correct the air quality problem. Indiana's candidate contingency measures include the following:

• Vehicle Inspection and Maintenance Enhancements
• Alternative Fuel and Diesel Retrofit Programs
• NO_X and SO₂ Emission Offsets for New and Modified Major Sources
• NO_X and SO₂ Emission Offsets for New and Modified Minor Sources
• Increased Offset Ratio for New Sources
• NO_X and SO₂ Controls on New Minor Sources
• Wood Stove Change-Out Program
• Increased Recovery Efficiency at Sulfur Recovery Plants
• Various Emission Reduction Measures or Dust Suppression for Unpaved Roads and/or Parking Lots
• Idling Restrictions
• Broader Geographic Applicability of Existing Measures, and
• Various Transportation Control Measures Sufficient To Achieve At Least a 0.5 Percent Reduction in Area-Wide PM_2.5 Precursor Emissions.

Under Indiana's plan, control measures are to be adopted and implemented within 18 months from the end of the season in which air quality triggering the Action Level Response occurs. Indiana further commits to conduct an ongoing review of its monitored data, and if monitored concentrations or emissions are trending upward, Indiana commits to take appropriate steps to avoid a violation if possible. EPA contends that Indiana's contingency plan satisfies the pertinent requirements of section 175A(d).

As required by section 175A(b) of the CAA, Indiana commits to submit to the EPA an updated PM_2.5 maintenance plan eight years after redesignation of Lake and Porter Counties to assure maintenance for an additional ten-year period beyond the initial maintenance period. As required by section 175A of the CAA, Indiana has also committed to retain the PM_2.5 control measures contained in the SIP prior to redesignation.

For all of the reasons outlined above, EPA is proposing to approve Indiana's PM_2.5 maintenance plan for Lake and Porter Counties and the Greater Chicago area.

VI. Has the State adopted acceptable MVEBs for the PM_2.5 maintenance period?

Under section 176(c) of the CAA, transportation plans and Transportation Improvement Programs (TIPs) must be evaluated for conformity with SIPs. Consequently, Indiana's redesignation request provides MVEBs, conformance with which will assure that motor vehicle emissions are at or below levels that can be expected to provide for attainment and maintenance of the PM_2.5 NAAQS. Indiana's April 3, 2008, submittal included emission budgets for NO_X and PM_2.5 for 2010 and 2020. Indiana submitted a replacement set of budgets in its May 26, 2011, submittal. These updated budgets address the years 2016 and 2025. However, in a letter dated July 20, 2011, Indiana has requested that EPA not act on the 2016 MVEBs for Lake and Porter Counties because of concerns with the way in which these emission budgets were calculated. Since the 2025 emission budgets replace the emission budgets submitted in April 2008, EPA will no longer conduct rulemaking on the April 2008 MVEBs and will not act on the 2016 MVEBs per Indiana's request.

Table 9 shows the updated 2025 MVEBs as well as the 2025 emission projections on which these budgets are based. Table 9 also shows the 2008 on-road mobile source emissions, which are part of the emissions which have led to attainment of the 1997 annual PM_2.5 standard in the Chicago-Gary-Lake County, IL-IN area. Indiana did not provide emission budgets for SO₂, VOC, and ammonia because it concluded, consistent with EPA's presumptions regarding these PM_2.5 precursors, that emissions of these precursors from motor vehicles are not significant contributors to the area's PM_2.5 air quality problem.

Table 9—Mobile Source Emission Projections for Lake and Porter Counties

[Tons per year]

Year	NOX		Primary PM2.5
	Emissions estimate	Budget	Emissions estimate	Budget
2008	10,703.81		187.09
2025	2,534.95	2,915.19	115.39	132.70

Table 9 shows substantial decreases in on-road mobile source NO_X and primary PM_2.5 emissions from 2008 to 2025. The emission reductions are expected because newer vehicles, subject to more stringent emission standards, are continually replacing older, dirtier vehicles. Indiana provided emission budgets for 2025 that include a safety margin of 15 percent above projected levels. Safety margins are included in the MVEBs to account for the wide range of assumptions that are factored into the motor vehicle emission projections. The safety margins are constrained so as to prevent any increases in on-road emissions from interfering with the maintenance of the 1997 annual PM_2.5 standard during the maintenance period. In Lake and Porter Counties, the MVEBs and motor vehicle emission projections for both NO_X and primary PM_2.5 are lower than attainment year levels.

EPA is proposing to approve the 2025 Lake and Porter Counties MVEBs into the Indiana SIP because, based on our review of the submitted maintenance plan, we have determined that the maintenance plan and MVEBs meet EPA's criteria found in 40 CFR 93.118(e)(4) for determining that MVEBs are adequate for use in transportation conformity determinations and are approvable because, when considered together with the submitted maintenance plan projected emissions, they provide for maintenance of the 1997 annual PM_2.5 standard in the Chicago-Gary-Lake County, IL-IN area.

The budgets that Indiana submitted were calculated using the MOBILE6.2 motor vehicle emissions model. EPA is proposing to approve the inventory and the conformity emission budgets calculated using this model because this model was the most current model available at the time Indiana was performing its analysis. As noted above and separate from today's proposal, EPA has issued an updated motor vehicle emissions model known as the Motor Vehicle Emission Simulator (MOVES). In its announcement of this model, EPA established a two-year grace period for continued use of MOBILE6.2 in transportation conformity determinations for transportation plans and TIPs (extending to March 2, 2012), after which states and metropolitan planning organizations (other than California) must use MOVES for transportation plan and TIP conformity determinations. (See 75 FR 9411, March 2, 2010.)

Additional information on the use of MOVES in SIPs and conformity determinations can be found in the December 2009 “Policy Guidance on the Use of MOVES2010 for State Implementation Plan Development, Transportation Conformity, and Other Purposes.” This guidance document is available at: http://www.epa.gov/​otaq/​models/​moves/​420b09046.pdf. During the conformity grace period, the state and MPO(s) should use the interagency consultation process to examine how MOVES2010a will impact their future transportation plan and TIP conformity determinations, including regional emissions analyses. For example, an increase in emission estimates due to the use of MOVES2010a may affect an area's ability to demonstrate conformity for its transportation plan and/or TIP. Therefore, state and local planners should carefully consider whether the SIP and MVEBs, transportation plans, and TIPs should be revised with MOVES2010a before the end of the conformity grace period, since doing so may be necessary to ensure conformity determinations in the future.

We would expect that states and metropolitan planning organizations would work closely with EPA and the local Federal Highway Administration and Federal Transit Administration offices to determine an appropriate course of action to address this type of situation if it is expected to occur. If Indiana chooses to revise the Lake and Porter Counties maintenance plan, it should consult the response to Question 7 of the December 2009 Policy Guidance on the Use of MOVES2010 for State Implementation Plan Development, Transportation Conformity, and Other Purposes for information on requirements related to such revisions.

VII. Are the base year emissions inventories for Lake and Porter Counties approvable under CAA section 172(c)(3)?

In addition to air quality data supporting the State's PM_2.5 redesignation request, emissions data are needed to meet CAA emission inventory requirements. Under section 172(c)(3) of the CAA, Indiana is required to submit comprehensive, accurate, and current inventories of actual emissions of PM_2.5 and PM_2.5 precursors for each PM_2.5 nonattainment area.

As noted in table 2 above, Indiana has documented 2002 and 2005 NO_X, SO₂, and primary PM_2.5 emissions for Lake and Porter Counties. The 2005 emission inventories (and those for other years summarized above) are documented in appendices B through G of Indiana's May 26, 2011, submittal. General techniques used derive these emissions were documented in the revised PM_2.5 redesignation request included with the May 26, 2011, submittal. These derivation techniques and sources of information were discussed above in section V.C.2 of this proposed action. EPA has reviewed Indiana's documentation of the emissions inventory techniques and the data sources used for the derivation of the 2005 base year emissions and has found that Indiana has thoroughly documented the derivation of these emissions inventories.

In the May 26, 2011, submittal, IDEM states that the 2005 base year emissions inventories (and the 2008 attainment year emissions inventories) are currently the most complete emissions inventories for PM_2.5 and PM_2.5 precursors in Lake and Porter Counties. We conclude that the 2005 emissions inventories are complete and are as accurate as possible given the input data available to the state. Therefore, we propose to approve the 2005 PM_2.5 emissions inventories for Lake and Porter Counties as meeting the requirement of section 172(c)(3) of the CAA.

VIII. What are EPA's proposed actions and what are the effects of these proposed actions?

In its rulemaking of November 27, 2009, EPA determined that the Greater Chicago area has attained the 1997 annual PM_2.5 NAAQS. EPA's review of more recent data indicates that the area continues to attain this standard. Thus, EPA is proposing to determine that the area continues to attain the 1997 annual PM_2.5 standard. EPA is also proposing to approve Indiana's maintenance plan for Lake and Porter Counties as a SIP revision that meets the requirements of section 175A of the CAA. EPA proposes to approve the 2005 emission inventories for Lake and Porter Counties included in Indiana's May 26, 2011, submittal as satisfying the requirement in section 172(c)(3) of the CAA. Pursuant to section 107(d)(3)(E) of the CAA, EPA proposes to approve the State of Indiana's request to redesignate Lake and Porter Counties, Indiana to attainment of the 1997 annual PM_2.5 NAAQS. Finally, EPA is proposing to find adequate and to approve 2025 MVEBs for Lake and Porter Counties for purposes of future transportation conformity.

If finalized, approval of the redesignation request would change the legal designation of Lake and Porter Counties for the 1997 annual PM_2.5 NAAQS, found at 40 CFR part 81, from nonattainment to attainment. Finalizing EPA's proposal to approve several revisions to the Indiana SIP for Lake and Porter Counties would approve into the Indiana SIP the Lake and Porter Counties' 1997 annual PM_2.5 maintenance plan, the 2005 emission inventories submitted with the maintenance plan, and 2025 MVEBs.

IX. Statutory and Executive Order Reviews

Under the CAA, redesignation of an area to attainment and the accompanying approval of a maintenance plan under section 107(d)(3)(E) are actions that affect the status of a geographical area and do not impose any additional regulatory requirements on sources beyond those imposed by state law. A redesignation to attainment does not in and of itself create any new requirements, but rather results in the applicability of requirements contained in the CAA for areas that have been redesignated to attainment. Moreover, the Administrator is required to approve a SIP submission that complies with the provisions of the CAA and applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria of the CAA. Accordingly, this action merely proposes to approve state law as meeting Federal requirements and does not impose additional requirements beyond those imposed by state law. For that reason, these actions:

• Are not a “significant regulatory action” subject to review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993);
• Do not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• Are certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.);
• Do not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L.104-4);
• Do not have Federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Are not economically significant regulatory actions based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);
• Are not significant regulatory actions subject to Executive Order 13211 (66 FR 28355, May 22, 2001);
• Are not subject to requirements of Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the CAA; and
• Do not provide EPA with the discretionary authority to address, as appropriate, disproportionate human health or environmental effects, using practicable and legally permissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).

In addition, this proposed rule does not have tribal implications as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), because the SIP is not approved to apply in Indian country located in the state, and EPA notes that it will not impose substantial direct costs on tribal governments or preempt tribal law.

List of Subjects in 40 CFR Part 52

• Environmental protection
• Air pollution control
• Incorporation by reference
• Intergovernmental relations
• Particulate matter

Dated: September 12, 2011.

Susan Hedman,

Regional Administrator, Region 5.

Footnotes

1.  Primary PM_2.5 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.  NO_X and SO₂ are precursors for fine particulates formed through chemical reactions and other related processes in the atmosphere.

3.  Transportation conformity assures that emissions from on-road mobile sources do not jeopardize continued maintenance of the standard during the maintenance period.

4.  Emissions for the Illinois portion of the PM_2.5 nonattainment area must be considered along with the emissions for Lake and Porter Counties to demonstrate the emission reductions resulting in attainment of the PM_2.5 standard and to demonstrate maintenance of the PM_2.5 standard for the entire bi-state PM_2.5 nonattainment area.

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.

6.  We acknowledge that differences in individual State EGU emission totals will actually occur under CSAPR because the implementation of this rule will provide for emissions trading and because each State's EGU emissions budget will be supplemented with source variability limits and new source set-asides. Nonetheless, the regional total EGU emissions will be significantly reduced as a result of the implementation of CSAPR.