Air Plan Approval; Pennsylvania; Redesignation Request and Associated Maintenance Plan for the Liberty-Clairton Area for the 1997 Annual and 2006 24-Hour Fine Particulate Matter Standard and Maintenance Plan for the Allegheny County Area for the 2012 Annual Fine Particulate Matter Standard

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Parts 52 and 81</CFR> <DEPDOC>[EPA-R03-OAR-2024-0586; FRL-10536-01-R3]</DEPDOC> <SUBJECT>Air Plan Approval; Pennsylvania; Redesignation Request and Associated Maintenance Plan for the Liberty-Clairton Area for the 1997 Annual and 2006 24-Hour Fine Particulate Matter Standard and Maintenance Plan for the Allegheny County Area for the 2012 Annual Fine Particulate Matter Standard</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Proposed rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA) is proposing to approve a request from the Commonwealth of Pennsylvania to redesignate the Liberty-Clairton, Pennsylvania nonattainment area (Liberty-Clairton Area) to attainment for the 1997 annual and 2006 24-hour fine particulate matter (PM <E T="52">2.5</E> ) national ambient air quality standards (NAAQS or standard). The EPA is also proposing to approve, as revisions to the Pennsylvania state implementation plan (SIP), the Commonwealth's plan for maintaining the 1997 annual and 2006 24-hour PM <E T="52">2.5</E> NAAQS through 2035 for the Liberty-Clairton Area. Additionally, the EPA is proposing to approve the maintenance plan for the Allegheny County, Pennsylvania nonattainment area (Allegheny County Area) for the 2012 annual PM <E T="52">2.5</E> NAAQS through 2035. The maintenance plan includes 2017, 2026, and 2035 mobile vehicle emissions budgets (MVEBs) for mobile sources of PM <E T="52">2.5</E> and nitrogen oxides (NO <E T="52">X</E> ) for the Allegheny County Area. The EPA is proposing to find these 2017, 2026, and 2035 MVEBs for PM <E T="52">2.5</E> and NO <E T="52">X</E> adequate and to approve these MVEBs into the Pennsylvania SIP for transportation conformity purposes. This action does not redesignate the Allegheny County Area to attainment for the 2012 annual PM <E T="52">2.5</E> NAAQS, as Pennsylvania withdrew its redesignation request specific to the Allegheny County Area. The redesignation request and maintenance plan were submitted by the Commonwealth of Pennsylvania Department of Environmental Protection (PADEP or Pennsylvania) on behalf of the Allegheny County Health Department (ACHD). This action is being taken under the CAA. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Written comments must be received on or before May 7, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R03-OAR-2024-0586 at <E T="03">www.regulations.gov,</E> or via email to <E T="03">gordon.mike@epa.gov</E> . For comments submitted at <E T="03">Regulations.gov,</E> follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from <E T="03">Regulations.gov</E> . For either manner of submission, the EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be confidential business information (CBI) 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). For additional submission methods, please contact the person identified in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section. For the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit <E T="03">www.epa.gov/dockets/commenting-epa-dockets</E> . <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Ian Neiswinter, Planning & Implementation Branch (3AD30), Air & Radiation Division, U.S. Environmental Protection Agency, Region III, 1600 John F. Kennedy Boulevard, Philadelphia, Pennsylvania 19103. The telephone number is (215) 814-2011. Mr. Neiswinter can also be reached via electronic mail at <E T="03">neiswinter.ian@epa.gov</E> . </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document, wherever “we,” “us,” or “our” are used, it is intended to refer to the EPA. <HD SOURCE="HD1">I. What action is the EPA proposing?</HD> On November 30, 2022, the EPA received from PADEP, on behalf of ACHD, a redesignation request for the Liberty-Clairton Area for the 1997 annual and 2006 24-hour PM <E T="52">2.5</E> NAAQS and for the Allegheny County Area for the 2012 annual PM <E T="52">2.5</E> NAAQS. <SU>1</SU> <FTREF/> As part of the request, PADEP submitted, as a Pennsylvania SIP revision, a combined maintenance plan for each area's respective NAAQS to ensure continued attainment throughout the areas over the next 10 years as required by CAA section 107(d)(3)(E)(iv). On May 2, 2024, PADEP submitted to the EPA a partial withdrawal of the November 30, 2022, SIP revision. In that letter, PADEP withdrew only the portion of the SIP revision pertaining to the request to redesignate the Allegheny County Area to attainment for the 2012 annual PM <E T="52">2.5</E> NAAQS. However, PADEP retained the portion of the SIP revision pertaining to the maintenance plan for the Allegheny County Area for the 2012 annual PM <E T="52">2.5</E> NAAQS and retained the request to redesignate the Liberty-Clairton Area for the 1997 annual and 2006 24-hour PM <E T="52">2.5</E> NAAQS to attainment along with the associated maintenance plan for the Liberty-Clairton Area. <FTNT> <SU>1</SU>  The Liberty-Clairton Area is comprised of the following municipalities in Allegheny County, Pennsylvania: the boroughs of Liberty, Lincoln, Port Vue, and Glassport, and the City of Clairton. The Allegheny County Area is comprised of all municipalities within Allegheny County, Pennsylvania, and subsumes the municipalities which comprise the Liberty-Clairton Area. The table listed at 40 Code of Federal Regulations (CFR) 81.339 defines NAAQS area designations within Pennsylvania. </FTNT> The EPA is proposing to take the following actions for the Liberty-Clairton Area: (1) to redesignate the Liberty-Clairton Area to attainment for the 1997 annual and 2006 24-hour PM <E T="52">2.5</E> NAAQS; and (2) to approve into the Pennsylvania SIP the associated maintenance plan for the 1997 annual and 2006 24-hour PM <E T="52">2.5</E> NAAQS for the Liberty-Clairton Area. The EPA's proposed approval of the redesignation request and maintenance plan for the 1997 annual and 2006 24-hour PM <E T="52">2.5</E> NAAQS for the Liberty-Clairton Area is based upon the EPA's determination that the Liberty-Clairton Area continues to attain both standards, and that all other redesignation criteria have been met for the Liberty-Clairton Area. The EPA is also proposing the following actions for the Allegheny County Area: (1) to approve into the Pennsylvania SIP the maintenance plan for the 2012 annual PM <E T="52">2.5</E> NAAQS; and (2) to find the 2017, 2026, and 2035 MVEBs for PM <E T="52">2.5</E> and NO <E T="52">X</E> adequate and approve these MVEBs into the Pennsylvania SIP for transportation conformity purposes. The adequacy comment period for these MVEBs will begin upon publication of this notice of proposed rulemaking (NPRM). Please see section IV of this rulemaking for further explanation of the MVEBs and the adequacy process. This action does not redesignate the Allegheny County Area to attainment for the 2012 annual PM <E T="52">2.5</E> NAAQS. The EPA may approve a maintenance plan as meeting the requirements under CAA section 175A without redesignating an area to attainment. <SU>2</SU> <FTREF/> Notably, all applicable nonattainment area requirements for the Allegheny County Area for the 2012 annual PM <E T="52">2.5</E> NAAQS shall remain in place until such time as Pennsylvania submits a request for redesignation pursuant to section 107(d)(3) of the CAA and the EPA determines that the Allegheny County Area meets the CAA requirements for redesignation to attainment and takes action to redesignate the Allegheny County Area for the 2012 annual PM <E T="52">2.5</E> NAAQS. These proposed actions are summarized and described in greater detail throughout this proposed rulemaking. <FTNT> <SU>2</SU>   <E T="03">See</E> Pg. 7 of “Procedures for Processing Requests to Redesignate Areas to Attainment,” Memorandum from John Calcagni, Director, Air Quality Management Division, September 4, 1992. </FTNT> <HD SOURCE="HD1">II. Background</HD> <HD SOURCE="HD2"> A. The PM <E T="54">2.5</E> NAAQS </HD> Fine particulate pollution can be emitted directly from a source (primary PM <E T="52">2.5</E> ) or formed secondarily through chemical reactions in the atmosphere involving precursor pollutants emitted from a variety of sources. The main precursors of secondary PM <E T="52">2.5</E> are sulfur dioxide (SO <E T="52">2</E> ), nitrogen dioxide (NO <E T="52">X</E> ), ammonia (NH <E T="52">3</E> ), and volatile organic compounds (VOCs). <SU>3</SU> <FTREF/> Sulfates are a type of secondary particulate formed from SO <E T="52">2</E> emissions from power plants and industrial facilities. Nitrates, another common type of secondary particulate, are formed from combustion emissions of NO <E T="52">X</E> from power plants, mobile sources, and other combustion sources. <FTNT> <SU>3</SU>   <E T="03">See</E> 81 FR 58010 (August 24, 2016). </FTNT> The first air quality standards for PM <E T="52">2.5</E> were established on July 18, 1997 (62 FR 38652). The EPA promulgated an annual standard at a level of 15 micrograms per cubic meter (μg/m <SU>3</SU> ), based on a three-year average o ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 104k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━