Air Plan Approval; Montana; Missoula, Montana Oxygenated Fuels Program Removal, Carbon Monoxide, Limited Maintenance Plan

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R08-OAR-2023-0473; FRL-12257-01-R8]</DEPDOC> <SUBJECT>Air Plan Approval; Montana; Missoula, Montana Oxygenated Fuels Program Removal, Carbon Monoxide, Limited Maintenance Plan</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 State Implementation Plan (SIP) revision submitted by the Montana Department of Environmental Quality (MDEQ or “the State”), on January 30, 2024, requesting to change the status of gasoline requirements (the “oxygenated fuels” or “oxyfuels” program”) in the Missoula, Montana, Carbon Monoxide (CO) limited maintenance plan (LMP) area from an active control measure to a contingency measure. The SIP revision contains a non-interference demonstration under the Clean Air Act (CAA), which concludes that converting the oxygenated gasoline program from a control measure to a contingency measure in the Missoula CO LMP would not interfere with attainment or maintenance of the CO National Ambient Air Quality Standards (NAAQS). The EPA is proposing to approve Montana's SIP submittal pursuant to CAA. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Written comments must be received on or before November 14, 2024. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R08-OAR-2023-0473, to the Federal Rulemaking Portal: <E T="03">https://www.regulations.gov</E> . Follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from <E T="03">https://www.regulations.gov</E> . 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">https://www2.epa.gov/dockets/commenting-epa-dockets</E> . <E T="03">Docket:</E> All documents in the docket are listed in the <E T="03">https://www.regulations.gov</E> index. Although listed in the index, some information is not publicly available, <E T="03">e.g.,</E> 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 electronically in <E T="03">https://www.regulations.gov</E> . Please email or call the person listed in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section if you need to make alternative arrangements for access to the docket. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Joseph Stein, Air and Radiation Division, EPA, Region 8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver, Colorado 80202-1129, telephone number: (303) 312-7078, email address: <E T="03">stein.joseph@epa.gov</E> . </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document wherever “we,” “us,” or “our” is used, we mean the EPA. <HD SOURCE="HD1">I. Background</HD> The EPA is proposing to approve a SIP revision submitted by Montana on January 30, 2024, requesting to change the status of the oxyfuels program in the Missoula CO LMP from an active control measure to a contingency measure. To support the request, Montana's January 30, 2024 SIP revision contains technical support materials to demonstrate that the removal of the rules as a control measure will not interfere with attainment or maintenance of the CO NAAQS or with any other applicable requirement of the CAA. In addition to the technical support materials provided by Montana, the EPA has provided supplemental technical support documentation to further demonstrate non-interference. <SU>1</SU> <FTREF/> Specifically, these SIP revisions address State regulations amended in the Missoula City-County Air Pollution Control (MCCAPC) program rules, Chapter 10: <E T="03">Fuels,</E> Subchapter 1: <E T="03">Oxygenated Fuels Program,</E> rules 10.102(1), 10.105(1), 10.109(1), 10.110, 10.111, 10.111(2). <FTNT> <SU>1</SU>   <E T="03">See MEMO_Missoula MOVES TSD_CO OxyFuels 110(l).docx</E> in docket. </FTNT> The EPA's analysis of Montana's January 30, 2024 SIP revision that is the subject of this proposed rule is organized into two parts under section II. of this document. Part A provides the background, analysis, and discussion of the non-interference demonstration for the change in status of Montana's oxyfuels program from a control measure to a contingency measure in the federally approved Montana SIP; Part B contains information regarding rules submitted for revision in MCCAPC Chapter 10: <E T="03">Fuels,</E> Subchapter 1: <E T="03">Oxygenated Fuels Program</E> . The EPA is proposing to act on the revisions listed in this action and will act on the additional rule revisions listed in the January 30, 2024 SIP revision submission in a separate action. <HD SOURCE="HD1">II. The EPA's Evaluation</HD> <HD SOURCE="HD2">A. Removal of the Oxygenated Gasoline Program as a Control Measure</HD> <HD SOURCE="HD3">1. Missoula, Montana Oxygenated Gasoline Program and CO NAAQS Maintenance</HD> The EPA designated Missoula, Montana, as nonattainment for CO under the provisions of the 1977 CAA Amendments on March 3, 1978 (43 FR 8962). Under the CAA Amendments of 1990, the Missoula area was designated as nonattainment and classified as a “Moderate” CO area, with a design value of less than or equal to 12.7 parts per million (ppm) and was required to attain the CO NAAQS by December 31, 1995 (56 FR 56694, November 6, 1991). <SU>2</SU> <FTREF/> Under section 211(m) of the CAA, states with areas designated nonattainment for CO with certain design values were required to submit revisions to their SIPs and implement oxygenated gasoline programs by no later than November 1, 1992. As a result, the State submitted such a revision, and the EPA approved an oxygenated gasoline program for the Missoula area on November 8, 1994 (59 FR 55585). The oxygenated gasoline program applies during the high CO season, which is generally during the colder winter months when cars tend to have higher tailpipe CO emissions. The oxygenated gasoline program also requires that gasoline contain at least 2.7% oxygen by weight during the high CO season. This requirement is intended to ensure complete gasoline combustion and thus achieve a reduction in tailpipe CO emissions. The high CO season for the Missoula CO area was established as November 1 through the last day of February of each year. <FTNT> <SU>2</SU>  Further information regarding this classification and the accompanying requirements are described in the “General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990.” See 57 FR 13498, April 16, 1992. </FTNT> The CAA established an attainment date of December 31, 1995, for all Moderate CO areas, including the Missoula, Montana, area, triggering CAA section 211(m) requirements. CAA section 107(d)(3)(E) sets out the requirements that an area must meet to be redesignated from nonattainment to attainment, including that the area must have a fully approved maintenance plan pursuant to section 175A of the CAA. A maintenance plan, as defined in section 175A(a) of the CAA, is a revision to the SIP to provide for the maintenance of the NAAQS for the air pollutant in question in the area concerned for at least 10 years after the redesignation. CAA section 175A(d) requires that such plans include contingency provisions, as necessary, to promptly correct any violation of the NAAQS that occurs after redesignation of an area; this includes implementation of all control measures that were contained in the SIP prior to redesignation. While CAA section 175A sets forth the criteria for adequate maintenance plans, <SU>3</SU> <FTREF/> the EPA has also published longstanding guidance providing clarification for states on developing maintenance plans by performing air quality modeling to demonstrate that the future mix of sources and emission rates will not cause a violation of the NAAQS or by showing that projected future emission reductions of a pollutant and its precursors will not exceed the level of emissions during a year when the area was in attainment of the NAAQS. <SU>4</SU> <FTREF/> <FTNT> <SU>3</SU>   <E T="03">See</E> 42 U.S.C. 7505A(a). </FTNT> <FTNT> <SU>4</SU>   <E T="03">See</E> Memorandum from John Calcagni, Director, Air Quality Management Division, EPA Office of Air Quality Planning and Standards, “Procedures for Processing requests to Redesignate Areas to Attainment,” September 4, 1992 (Calcagni Memo). </FTNT> On May 27, 2005, the Governor of Montana submitted to the EPA a request to redesignate the Missoula CO nonattainment area to attainment for the 8-hour CO NAAQS. Along with this request, the Governor submitted a CAA section 175A(a) maintenance plan which established an attainment year of 2000, and demonstrated that the area would maintain the 8-hour CO NAAQS through 2020. The EPA approved the State's redesigna ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 31k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━