Visibility Protection: Regional Haze State Plan Requirements Rule Revision

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 51</CFR> <DEPDOC>[EPA-HQ-OAR-2025-1477; FRL-6714-04-OAR]</DEPDOC> <RIN>RIN 2060-AU01</RIN> <SUBJECT>Visibility Protection: Regional Haze State Plan Requirements Rule Revision</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Advance notice of proposed rulemaking. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA or Agency) is soliciting information and requesting comment to assist in the development of regulatory changes pertaining to the restructuring of the Regional Haze Rule (RHR). Under the current RHR, states must submit state implementation plans (SIPs) to protect visibility in mandatory Class I Federal areas (Class I areas) to demonstrate reasonable progress towards the national visibility goal. The Agency is seeking input regarding how the EPA can meaningfully revise the RHR to streamline regulatory requirements impacting states' visibility improvement obligations under the Clean Air Act (CAA). </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Comments must be received on or before December 1, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> You may send comments, identified by Docket ID No. EPA-HQ-OAR-2025-1477, by any of the following methods: <E T="03">Federal eRulemaking Portal:</E> <E T="03">https://www.regulations.gov/</E> (our preferred method). Follow the online instructions for submitting comments. <E T="03">Instructions:</E> All submissions received must include the Docket ID No. for this rulemaking. Comments received may be posted without change to <E T="03">https://www.regulations.gov/,</E> including any personal information provided. For detailed instructions on sending comments and additional information on the rulemaking process, see the “Public Participation” heading of the <E T="02">SUPPLEMENTARY INFORMATION</E> section of this document. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Ms. Paige Wantlin, Air Quality Policy Division, Office of Air Quality Planning and Standards (Mail code C539-01), Environmental Protection Agency, 109 TW Alexander Drive, Research Triangle Park, NC 27711; telephone number: (919) 541-5670; email address: <E T="03">Wantlin.Paige@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">Table of Contents</HD> <HD SOURCE="HD1">I. Public Participation</HD> <HD SOURCE="HD2">Written Comments</HD> Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2025-1477, at <E T="03">https://www.regulations.gov</E> (our preferred method), or the other methods identified in the <E T="02">ADDRESSES</E> section. Once submitted, comments cannot be edited or removed from the docket. The EPA may publish any comment received to its public docket. The EPA requests that reviewers and commenters number their responses, for example, if responding to Topic 1, Question 1.a., please use the Topic and Question within a header before providing a response. Do not submit to EPA's docket at <E T="03">https://www.regulations.gov</E> any information you consider to be Confidential Business Information (CBI), Proprietary Business Information (PBI), or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission ( <E T="03">i.e.,</E> on the web, cloud, or other file sharing system). Please visit <E T="03">https://www.epa.gov/dockets/commenting-epa-dockets</E> for additional submission methods; the full EPA public comment policy; information about CBI, PBI, or multimedia submissions; and general guidance on making effective comments. <HD SOURCE="HD1">II. General Information</HD> <HD SOURCE="HD2">A. Preamble Glossary of Terms and Acronyms</HD> The following are abbreviations of terms used in this document. <EXTRACT> <FP SOURCE="FP-1">ANPRM Advance notice of proposed rulemaking</FP> <FP SOURCE="FP-1"> NH <E T="52">3</E>  Ammonia </FP> <FP SOURCE="FP-1">BACT Best available control technology</FP> <FP SOURCE="FP-1">BART Best available retrofit technology</FP> <FP SOURCE="FP-1">CAA Clean Air Act</FP> <FP SOURCE="FP-1">CBI Confidential business information</FP> <FP SOURCE="FP-1">CFR Code of Federal Regulations</FP> <FP SOURCE="FP-1">Class I areas Class I Federal areas</FP> <FP SOURCE="FP-1">EPA Environmental Protection Agency</FP> <FP SOURCE="FP-1">FIP Federal implementation plan</FP> <FP SOURCE="FP-1">FLM Federal land manager</FP> <FP SOURCE="FP-1">LAER Lowest achievable emissions rate</FP> <FP SOURCE="FP-1">NAAQS National Ambient Air Quality Standards</FP> <FP SOURCE="FP-1"> NO <E T="52">X</E>  Nitrogen oxide </FP> <FP SOURCE="FP-1">OMB Office of Management and Budget</FP> <FP SOURCE="FP-1">PM Particulate matter</FP> <FP SOURCE="FP-1"> PM <E T="52">2.5</E>  Particulate matter equal to or less than 2.5 microns in diameter (fine particulate matter) </FP> <FP SOURCE="FP-1"> PM <E T="52">10</E>  Particulate matter equal to or less than 10 microns in diameter </FP> <FP SOURCE="FP-1">PSD Prevention of significant deterioration</FP> <FP SOURCE="FP-1">PBI Proprietary business information</FP> <FP SOURCE="FP-1">RACT Reasonable available control technology</FP> <FP SOURCE="FP-1">RAVI Reasonably attributable visibility impairment</FP> <FP SOURCE="FP-1">RPG Reasonable progress goal</FP> <FP SOURCE="FP-1">RHR Regional Haze Rule</FP> <FP SOURCE="FP-1">SIP State implementation plan</FP> <FP SOURCE="FP-1"> SO <E T="52">2</E>  Sulfur dioxide </FP> <FP SOURCE="FP-1">URP Uniform rate of progress</FP> <FP SOURCE="FP-1">U.S. United States</FP> <FP SOURCE="FP-1">VOC Volatile organic compound</FP> </EXTRACT> <HD SOURCE="HD2"> B. How is this <E T="7462">Federal Register</E> document organized? </HD> The information presented in this document is organized as follows: <EXTRACT> <FP SOURCE="FP-2">I. Public Participation</FP> <FP SOURCE="FP-2"> II. General Information </FP> <FP SOURCE="FP1-2">A. Preamble Glossary of Terms and Acronyms</FP> <FP SOURCE="FP1-2"> B. How is this <E T="04">Federal Register</E> document organized? </FP> <FP SOURCE="FP1-2">C. Executive Summary</FP> <FP SOURCE="FP1-2">D. What is the purpose of this ANPRM?</FP> <FP SOURCE="FP1-2">E. Does this action apply to me?</FP> <FP SOURCE="FP-2">III. What is the background for the EPA's proposed action?</FP> <FP SOURCE="FP1-2">A. Regional Haze</FP> <FP SOURCE="FP1-2">B. Requirements for Regional Haze SIPs for the First Planning Period</FP> <FP SOURCE="FP1-2">C. Requirements for Regional Haze SIPs for the Second Planning Period</FP> <FP SOURCE="FP1-2">D. EPA's 2024 Non-Regulatory Docket</FP> <FP SOURCE="FP-2">IV. Request for Comments and Feedback</FP> <FP SOURCE="FP1-2">A. Overview and Introduction</FP> <FP SOURCE="FP1-2">B. Topic 1: Development and Implementation of a Reasonable Progress Metric and Consideration of the Four Statutory Factors</FP> <FP SOURCE="FP1-2">C. Topic 2: Development of Criteria Used To Determine When a SIP Revision Is Necessary</FP> <FP SOURCE="FP1-2">D. Topic 3: Determining SIP Content Requirements</FP> <FP SOURCE="FP-2">V. Request for Comment and Additional Information</FP> <FP SOURCE="FP-2">VI. What are the next steps EPA will take?</FP> <FP SOURCE="FP-2">VII. Statutory and Executive Orders Reviews</FP> </EXTRACT> <HD SOURCE="HD2">C. Executive Summary</HD> The Regional Haze program, established under Clean Air Act sections 169A and 169B, pertains to addressing visibility impairment in the 156 mandatory class I Federal areas, which includes specific national parks and wilderness areas. The program targets visibility impairment caused by manmade air pollution, primarily from industrial sources, vehicles, and other human activities. Emissions of pollutants such as sulfur dioxide (SO <E T="52">2</E> ), nitrogen oxides (NO <E T="52">X</E> ), and particulate matter contribute significantly to Regional Haze. The goals of the program are to prevent future, and remedy existing, impairment of visibility in identified Class I areas from manmade air pollution. A key statutory component of the program is the requirement for states to develop state implementation plans (SIPs), which outline strategies for achieving reasonable progress toward the national visibility goal articulated under CAA section 169A(a)(1). <SU>1</SU> <FTREF/> States are also tasked with monitoring visibility conditions and reporting progress to the EPA, including tracking emissions reductions and visibility improvements at Class I areas. <SU>2</SU> <FTREF/> <FTNT> <SU>1</SU>  “Congress hereby declares as a national goal the prevention of any future, and the remedying of any existing, impairment of visibility in mandatory class I Federal areas which impairment results from manmade air pollution.” </FTNT> <FTNT> <SU>2</SU>  See 40 CFR 51.308(f)(6). </FTNT> Throughout the implementation of the second planning period, we received feedback from different stakeholder groups regarding the unclear and resource intensive requirements of the Regional Haze program. For example, some stakeholders (including various state air agencies and regional planning organizations) commented that the process of developing a Haze SIP revision is burdensome to both the states and the EPA and that the EPA should provide regulatory clarity regarding states' SIP revision obligations. <SU>3</SU> <FTREF/> In response to this feedback, on March 12, 2025, the EPA announced that a priority would be restructuring the Regional Haze program. <SU>4</SU> <FTREF/> Consistent with this announcement, t ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 70k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━