Redesignation of Portions of Westmoreland and Cambria Counties, Pennsylvania for the 2010 Sulfur Dioxide (SO2) National Ambient Air Quality Standards (NAAQS)

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 81</CFR> <DEPDOC>[EPA-R03-OAR-2023-0419; FRL-11736-02-R3]</DEPDOC> <SUBJECT> Redesignation of Portions of Westmoreland and Cambria Counties, Pennsylvania for the 2010 Sulfur Dioxide (SO <E T="0735">2</E> ) National Ambient Air Quality Standards (NAAQS) </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 (the EPA or the Agency) is finalizing the redesignation of portions of Cambria County and Westmoreland County, Pennsylvania, to “nonattainment” for the 2010 1-hour primary sulfur dioxide (SO <E T="52">2</E> ) national ambient air quality standard (NAAQS or standard). Westmoreland County was previously designated “attainment/ unclassifiable,” and Cambria County was designated “unclassifiable.” The EPA notified the Commonwealth of Pennsylvania of its intended redesignation of portions of Cambria and Westmoreland counties on February 17, 2023, and published a Notice of Availability (NOA) for this action on February 12, 2024. The EPA's redesignation of portions of these counties is based on modeled violations of the 2010 1-hour primary SO <E T="52">2</E> NAAQS. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This final rule is effective on January 16, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> The EPA has established a docket for this redesignation under Docket ID Number EPA-R03-OAR-2023-0419. All documents in the docket are listed on the <E T="03">www.regulations.gov website.</E> Although listed in the index, some information is not publicly available, <E T="03">e.g.,</E> confidential business information (CBI) 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 through <E T="03">www.regulations.gov, o</E> r please contact the person identified in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section for additional availability information. The EPA has established a website for the designations for the 2010 SO <E T="52">2</E> NAAQS at <E T="03">www.epa.gov/sulfur-dioxide-designations/sulfurdioxide-designations-regulatory-actions.</E> This final redesignation action, associated technical support documents, and other related information will be added to this website. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Ellen Schmitt, 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) 814-5787. Ms. Schmitt can also be reached via electronic mail at <E T="03">schmitt.ellen@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">I. Background and Purpose of the EPA's Final Action</HD> The EPA is required by Clean Air Act (CAA) section 107(d) to designate all areas throughout the nation as attaining or not attaining the NAAQS within two years of the promulgation of any new or revised NAAQS. Pursuant to CAA section 107(d), the EPA must designate as “nonattainment” those areas that violate the NAAQS and those nearby areas that contribute to violations. Once an area has been designated, the EPA Administrator, under CAA section 107(d)(3), may at any time notify a state that a designation should be revised. Under section 109 of the CAA, the EPA has established primary and secondary NAAQS for certain pervasive air pollutants and conducts periodic reviews of the NAAQS to determine whether they should be revised or whether new NAAQS should be established. The primary NAAQS represent ambient air quality standards, the attainment and maintenance of which the EPA has determined, including a margin of safety, are requisite to protect the public health. The secondary NAAQS represent ambient air quality standards, the attainment and maintenance of which the EPA has determined are requisite to protect the public welfare from any known or anticipated adverse effects associated with the presence of such air pollutant in the ambient air. On June 22, 2010 (75 FR 35520), the EPA finalized the revision of the 1-hour primary SO <E T="52">2</E> NAAQS, codified at 40 Code of Federal Regulations (CFR) 50.17, which became effective on August 23, 2010 (hereafter referred to as the 2010 SO <E T="52">2</E> NAAQS). The 2010 SO <E T="52">2</E> NAAQS is met at an ambient air quality monitoring site (or in the case of dispersion modeling, at an ambient air quality receptor location) when the 3-year average of the annual 99th percentile of daily maximum 1-hour average concentrations is less than or equal to 75 parts per billion (ppb), as determined in accordance with appendix T of 40 CFR part 50. 40 CFR 50.17(a) and (b). The EPA was required to designate areas throughout the country for the 2010 SO <E T="52">2</E> NAAQS by June 3, 2012. The EPA invoked a 1-year extension of the deadline to designate areas for the 2010 SO <E T="52">2</E> NAAQS, as provided for under CAA section 107, after which the Agency completed an initial round of SO <E T="52">2</E> designations for certain areas of the country on August 5, 2013 (referred to as “Round 1”). <SU>1</SU> <FTREF/> In Round 1, the EPA designated Indiana County, Pennsylvania and a portion of Armstrong County, Pennsylvania as nonattainment (hereafter referred collectively as the “Indiana Area”). On January 9, 2018, <SU>2</SU> <FTREF/> in a subsequent round of designations for the 2010 SO <E T="52">2</E> NAAQS, Westmoreland County, Pennsylvania was designated as attainment/unclassifiable, and Cambria County, Pennsylvania was designated as unclassifiable. <FTNT> <SU>1</SU>  78 FR 47191. Effective date October 4, 2013. </FTNT> <FTNT> <SU>2</SU>  83 FR 1098. Effective date April 9, 2018. </FTNT> In 2018, during the public comment period for the proposed approval of the SO <E T="52">2</E> attainment SIP for the Indiana Area (83 FR 32606, July 13, 2018), the Sierra Club submitted a modeling analysis which claimed to also show violations of the SO <E T="52">2</E> NAAQS within portions of Westmoreland and Cambria counties due to SO <E T="52">2</E> emissions from sources located within the Indiana Area. <SU>3</SU> <FTREF/> In 2022, during the public comment period for the proposed partial disapproval and partial approval of the Indiana Area's attainment SIP (87 FR 15166, March 17, 2022), the EPA received additional dispersion modeling from the Sierra Club, and from Keystone-Conemaugh Projects, LLC (KEY-CON), <SU>4</SU> <FTREF/> focused on the Westmoreland and Cambria areas. The EPA also conducted its own modeling of those areas. Based on review of all modeling analyses, the EPA made the determination that there are modeled SO <E T="52">2</E> NAAQS violations outside of the existing Indiana Area, in portions of Westmoreland and Cambria counties, and accordingly notified the Governor of Pennsylvania in a letter dated February 17, 2023, of our intent to redesignate portions of Westmoreland and Cambria counties as nonattainment for the 2010 1-hour primary SO <E T="52">2</E> NAAQS, consistent with CAA section 107(d)(3)(A). <SU>5</SU> <FTREF/> On June 22, 2023, Acting Secretary for the Pennsylvania Department of Environmental Protection (PA DEP), Richard Negrin, responded to the EPA's letter but did not specify whether the Commonwealth agreed or disagreed with the EPA's determination to redesignate portions of Westmoreland and Cambria counties as nonattainment for the 2010 1-hour primary SO <E T="52">2</E> NAAQS. Instead, Pennsylvania's response included several comments questioning certain aspects of the Technical Support Document (TSD) that the EPA had developed and submitted to PA DEP with the February 17, 2023 redesignation letter. The EPA responded to the Commonwealth's comments in a January 2024 response to comments (RTC) document, which is in the docket associated with this action. <SU>6</SU> <FTREF/> <FTNT> <SU>3</SU>  Explained further in the NOA associated with this redesignation. See 89 FR 9817 (February 12, 2024). </FTNT> <FTNT> <SU>4</SU>  KEY-CON, licensee for the Keystone Generating Station located in Armstrong County and the Conemaugh Generating station located in Indiana County, provided modeling to support its comments rebutting modeling and views presented by the Sierra Club and the EPA. </FTNT> <FTNT> <SU>5</SU>  Located in the public docket for this redesignation at <E T="03">www.regulations.gov</E> under Docket ID No. EPA-R03-OAR-2023-0419. </FTNT> <FTNT> <SU>6</SU>  A copy of PA DEP's comments on the EPA's intended redesignation TSD and also the EPA's RTC replying to these comments, can be found in Docket No. EPA-R03-OAR-2023-0419 via <E T="03">www.regulations.gov.</E> </FTNT> The EPA is not required under CAA section 107(d)(3) to seek public comment during the redesignations process, but we elected to do so for this area to provide the public with an opportunity to give input for the EPA's consideration before promulgating any final redesignation. The EPA published a NOA for this action in the <E T="04">Federal Register</E> on February 12, 2024 (89 FR 9815). Upon publication of the NOA in the <E T="04">Federal Register</E> <E T="03">,</E> a 45-day public comment period began. This comment period closed on March 28, 2024, and yielded comments from seven commenters. A copy of the EPA's responses to the comments received from the public is also located in the docket for this action. <HD SOURCE="HD1">II. EPA's Redesignation Decision and Supporting Air Quality Information< ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 25k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━