Air Plan Approval; Indiana; Regional Haze Plan for the Second Implementation Period

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R05-OAR-2021-0963; FRL-12589-02-R5]</DEPDOC> <SUBJECT>Air Plan Approval; Indiana; Regional Haze Plan for the Second Implementation Period</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA) is approving the Regional Haze State Implementation Plan (SIP) revision for Indiana submitted by the Indiana Department of Environmental Management (IDEM or Indiana) on December 29, 2021, as satisfying applicable requirements under the Clean Air Act (CAA) and EPA's Regional Haze Rule (RHR) for the program's second implementation period. Indiana's SIP submission addresses the requirement that States must periodically revise their long-term strategies for making reasonable progress towards the national goal of preventing any future, and remedying any existing, anthropogenic impairment of visibility, including regional haze, in mandatory Class I Federal areas. Indiana's SIP submission also addresses other applicable requirements for the second implementation period of the regional haze program. EPA is taking this action pursuant to sections 110 and 169A of the CAA. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This final rule is effective on February 25, 2026. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> EPA has established a docket for this action under Docket ID No. EPA-R05-OAR-2021-0963. All documents in the docket are listed on the <E T="03">https://www.regulations.gov</E> website. Although listed in the index, some information is not publicly available, <E T="03">i.e.,</E> Confidential Business Information (CBI), Proprietary Business Information (PBI), or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are available either through <E T="03">https://www.regulations.gov</E> or at the 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 Charles Hatten, Environmental Engineer, at (312) 886-6031 before visiting the Region 5 office. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Charles Hatten, Air and Radiation Division (AR-18J), Environmental Protection Agency, Region 5, 77 West Jackson Boulevard, Chicago, Illinois 60604, (312) 886-6031, <E T="03">hatten.charles@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document whenever “we,” “us,” or “our” is used, we mean EPA. <HD SOURCE="HD1">Table of Contents</HD> <EXTRACT> <FP SOURCE="FP-2">I. Background</FP> <FP SOURCE="FP-2">II. Public Comment Process</FP> <FP SOURCE="FP-2">III. Summary of Public Comments and EPA's Responses</FP> <FP SOURCE="FP1-2">A. Comments Received</FP> <FP SOURCE="FP1-2">B. Comments and Responses That Are Not Specific to EPA's Uniform Rate of Progress (URP) Policy</FP> <FP SOURCE="FP1-2">C. Comments and Responses That Are Specific to EPA's URP Policy</FP> <FP SOURCE="FP1-2">D. EPA's Final Approval</FP> <FP SOURCE="FP-2">IV. Final Action</FP> <FP SOURCE="FP-2">V. Statutory and Executive Order Reviews</FP> </EXTRACT> <HD SOURCE="HD1">I. Background</HD> On December 29, 2021, IDEM submitted a revision to its SIP to address regional haze requirements for the second implementation period. IDEM made this SIP submission to satisfy the requirements of the CAA's regional haze program pursuant to CAA sections 169A and 169B and 40 CFR 51.308. On June 18, 2025 (90 FR 25944), EPA proposed to approve the Indiana regional haze SIP revision. In the notice of proposed rulemaking (NPRM), EPA proposed to find that Indiana's Regional Haze SIP submission satisfied the regional haze requirements for the second implementation period contained in 40 CFR 51.308(f). As described further in EPA's proposed approval, IDEM utilized technical analyses and its source selection methodology to target the sources with the highest potential to impair visibility at mandatory Class I areas. <SU>1</SU> <FTREF/> IDEM's initial list of twenty candidate sources for a four-factor analysis represented the majority of Indiana's emissions that may influence visibility impacts on out-of-state Class I areas. IDEM further refined that list by excluding eleven electric generating units (EGUs) that either had existing effective controls or that were not expected to continue operating beyond 2028. IDEM then proceeded with site-specific four-factor analyses for the remining nine non-EGU facilities identified through this process. A detailed analysis of Indiana's plan and EPA's evaluation are contained in the NPRM, dated June 18, 2025 (90 FR 25944), as well as the Technical Support Document (TSD), dated April 22, 2025, and will not be restated here. <FTNT> <SU>1</SU>  There are no Class I areas in Indiana. However, the RHR requires SIPs to address Class I areas located outside the state that may be affected by emissions from within the state. </FTNT> <HD SOURCE="HD1">II. Public Comment Process</HD> The public review and comment period on EPA's NPRM opened June 18, 2025, and was originally scheduled to close on July 18, 2025. On June 26, 2025, EPA received a comment letter from the National Parks Conservation Association, the Coalition to Protect America's National Parks, and the Sierra Club (Comment 1) requesting that EPA provide an additional 30 days for public comment on the NPRM. On July 16, 2025 (90 FR 31923), EPA published a NPRM extending the public review and comment period to August 18, 2025. During the review and comment period, EPA received relevant comments from the following individuals, businesses, agencies, and organizations: an individual identified as Kurtis K. (Comment 2); three anonymous commenters (Comments 3, 4, and 5); IDEM (Comment 6); Power Generators Air Coalition (Comment 7); Ameren Missouri, American Electric Power Company, Inc. on behalf of its operating companies, and Nebraska Public Power District (collectively referred as the “Utilities for Reasonable Progress”) (Comment 8); Ohio Valley Electric Corporation (OVEC) and Indiana-Kentucky Electric Corporation (IKEC) (Comment 9); Abrams Environmental Law Clinic, Artists for Environmental Restoration, Inc., Citizens Climate Lobby-Evansville Chapter, Conservation Law Center, Environmental Advocacy Center at the Northwestern Pritzker School of Law, Faith in Place, Hessville Dune Dusters, Izaak Walton League-Indiana Division, Izaak Walton League-Porter County Chapter, Just Transition Northwest Indiana, National Parks Conservation Association, Owen-Putnam Friends of the Forest, Save the Dunes, Sierra Club-Hoosier Chapter, and Tri-State Creation Care (collectively referred to as “Community Organizations”) (Comment 10); Mid-Atlantic/Northeast Visibility Union (MANEVU) regional planning organization (Comment 11); and National Parks Conservation Association, Sierra Club, Environmental Law & Policy Center, Coalition to Protect America's National Parks, Conservation Law Center, Save the Dunes, and the Indiana Division of the Izaak Walton League of America (collectively referred to as the “Conservation Groups”) (Comments 12 through 23). <HD SOURCE="HD1">III. Summary of Public Comments and EPA's Responses</HD> <HD SOURCE="HD2">A. Comments Received</HD> All comments received are included in the rulemaking docket for this action. In the December 19, 2025, Response to Comments document (RTC), which is included in the docket for this rulemaking, EPA provides summaries of and detailed responses to all significant comments that further explain the basis for our final action. In addition to the request to extend the public comment period, EPA received comments on the NPRM addressing several topics including, but not limited to, additional emissions monitoring, increased public engagement, climate resilience, visibility trends, public health, economic benefits, enforceability of retirements, existing effective controls, four-factor analyses, <SU>2</SU> <FTREF/> cost considerations, Best Available Retrofit Technology (BART), and impacts on local communities. Additionally, EPA received several comments regarding EPA's URP policy. <SU>3</SU> <FTREF/> <FTNT> <SU>2</SU>  Under CAA 169A(g)(1), the four statutory factors are the costs of compliance, the time necessary for compliance, the energy and non-air quality environmental impacts of compliance, and the remaining useful life of any potentially affected sources. See also 40 CFR 51.308(f)(2)(i). An evaluation of potential control options for sources of visibility impairing pollutants based on applying the four statutory factors in CAA section 169A(g)(1) is referred to as a “four-factor” analysis. </FTNT> <FTNT> <SU>3</SU>  A change in Agency policy was introduced in the approval of West Virginia's regional haze plan. See the April 18, 2025, (90 FR 16478) proposed rule) and the July 7, 2025, (90 FR 29737) final rule. </FTNT> EPA acknowledges the seven comments that were generally supportive of the proposed action and EPA's URP policy from Kurtis K. (Comment 2), two anonymous commenters (Comments 3-4), IDEM (Comment 6); PGen (Comment 7), Utilities for Reasonable Progress (Comment 8), as well as OVEC and IKEC (Comment 9). Comments received from the Community Organizations, MANEVU, and the Conservation Groups were generally opposed to EPA's proposed action: Comments 10—23. The comments, while summarized below, are available in full in the docket for this rulemaking and are addressed in EPA's December 19, ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 72k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━