Air Quality State Implementation Plans; Approval and Promulgations: Montana: Infrastructure Requirements for the 2015 Ozone National Ambient Air Quality Standards

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R08-OAR-2019-0418; FRL-12875-01-R8]</DEPDOC> <SUBJECT>Air Quality State Implementation Plans; Approval and Promulgations: Montana: Infrastructure Requirements for the 2015 Ozone National Ambient Air Quality Standards</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 elements of a state implementation plan (SIP) submission from Montana regarding the infrastructure requirements of the Clean Air Act (CAA) for the 2015 ozone National Ambient Air Quality Standards (NAAQS). The infrastructure requirements are designed to ensure that the structural components of each state's air quality management program are adequate to meet the state's responsibilities under the CAA. Additionally, EPA is proposing to approve Montana's request to update their SIP, to incorporate the most current version of the “Guideline on Air Quality Models.” The EPA is taking this action pursuant to the CAA. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Written comments must be received on or before August 15, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R08-OAR-2019-0418 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, 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> Amrita Singh, Air and Radiation Division, EPA, Region 8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver, Colorado, 80202-1129, telephone number: (303) 312-6103, email address: <E T="03">singh.amrita@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">Table of Contents</HD> <EXTRACT> <FP SOURCE="FP-2">I. What is the background of this SIP submission?</FP> <FP SOURCE="FP-2">II. What infrastructure elements are required under section 110(a)(1) and (2)?</FP> <FP SOURCE="FP-2">III. EPA's Analysis of This SIP Submission</FP> <FP SOURCE="FP-2">IV. What action is EPA taking?</FP> <FP SOURCE="FP-2">V. Statutory and Executive Order Reviews</FP> </EXTRACT> <HD SOURCE="HD1">I. What is the background of this SIP submission?</HD> Whenever EPA promulgates a new or revised NAAQS, CAA section 110(a)(1) requires states to make SIP submissions to provide for the implementation, maintenance, and enforcement of the NAAQS. This type of SIP submission is commonly referred to as an “infrastructure SIP.” These submissions must meet the various requirements of CAA section 110(a)(2), as applicable. EPA has previously provided states with direction  <SU>1</SU> <FTREF/> on the application of these CAA provisions and through regional actions on infrastructure submissions. Unless otherwise noted below, we are following that existing approach in acting on this submission. In addition, in the context of acting on such infrastructure submissions, EPA evaluates the submitting state's SIP for factual compliance with statutory and regulatory requirements, not for the state's implementation of its SIP. EPA has other authority to address any issues concerning a state's implementation of the rules, regulations, consent orders, etc. that comprise its SIP. <FTNT> <SU>1</SU>  Available at: <E T="03">https://www3.epa.gov/airquality/urbanair/sipstatus/docs/Guidance_on_Infrastructure_SIP_Elements_Multipollutant_FINAL_Sept_2013.pdf.</E> Hereinafter referred to as the “EPA 2013 Guidance.” </FTNT> The Montana Department of Environmental Quality (MDEQ) submitted the following revisions to its infrastructure SIP (ISIP): • 2015 Ozone ISIP submitted on October 1, 2018, and • Revisions to appendix W submitted on December 28, 2022. <HD SOURCE="HD1">II. What infrastructure elements are required under section 110(a)(1) and (2)?</HD> CAA section 110(a)(1) provides the procedural and timing requirements for SIP submissions after a new or revised NAAQS is promulgated. Section 110(a)(2) lists specific elements the SIP must contain or satisfy. These infrastructure elements include requirements such as modeling, monitoring, and emission inventories, which are designed to ensure attainment and maintenance of the NAAQS. The elements that are subject to this action are listed below: • Section 110(a)(2)(A): Emission limits and other control measures. • Section 110(a)(2)(B): Ambient air quality monitoring/data system. • Section 110(a)(2)(C): Program for enforcement of control measures/minor new source review (NSR)/prevention of significant deterioration (PSD). • Section 110(a)(2)(D): Interstate transport. • Section 110(a)(2)(E): Adequate resources and authority, conflict of interest, and oversight of local governments and regional agencies. • Section 110(a)(2)(F): Stationary source monitoring and reporting. • Section 110(a)(2)(G): Emergency powers. • Section 110(a)(2)(H): Future SIP revisions. • Section 110(a)(2)(I): Plan revisions for nonattainment areas (under part D); • Section 110(a)(2)(J): Consultation with government officials; public notification; and PSD and visibility protection. • Section 110(a)(2)(K): Air quality modeling/data. • Section 110(a)(2)(L): Permitting fees. • Section 110(a)(2)(M): Consultation/participation by affected local entities. <HD SOURCE="HD1">III. EPA's Analysis of This SIP Submission</HD> Montana provided a detailed synopsis of how various components of its SIP meet each of the applicable requirements in section 110(a)(2) for the 2015 ozone NAAQS. The following review evaluates the SIP's submission. <HD SOURCE="HD2">Section 110(a)(2)(A)—Emission Limits and Other Control Measures</HD> This section requires SIPs to include enforceable emission limits and other control measures, means or techniques, schedules for compliance, and other related matters. EPA has long interpreted emission limits and control measures for attaining the standards as being due when nonattainment planning requirements are due. <SU>2</SU> <FTREF/> In the context of an infrastructure SIP, EPA is not evaluating the existing SIP provisions for this purpose. Instead, EPA is only evaluating whether the State's SIP has basic structural provisions for the implementation of the NAAQS. <FTNT> <SU>2</SU>   <E T="03">See, e.g.,</E> EPA's final rule on “National Ambient Air Quality Standards for Lead.” 73 FR 66964 at 67034. </FTNT> The Montana Code Annotated (MCA) 75-2-112 gives MDEQ the authority to “adopt, amend, and repeal rules for the administration, implementation, and enforcement of this chapter. Montana implements a statewide program for permitting major and minor stationary sources of air pollution, including sources of ozone precursors. Specific control measures adopted in Montana Board of Environmental Review (BER) Orders, along with multiple SIP-approved state air quality regulations within the Administrative Rules of Montana (ARM) and cited in Montana's certifications, provide enforceable emission limitations and other control measures, means of techniques, schedules for compliance, and other related matters necessary to meet the requirements of CAA section 110(a)(2)(A) for the 2015 ozone NAAQS. Montana's certifications generally list provisions and enforceable control measures within its SIP which regulate pollutants through various programs, including its stationary permitting program which requires sources to demonstrate that emissions will not cause or contribute to violation of any NAAQS (ARM 17.8.749). In the case of Montana, this meets the requirements of section 110(a)(2)(A) for the 2015 ozone NAAQS. <HD SOURCE="HD2">Section 110(a)(2)(B)—Ambient Air Quality Monitoring/Data System</HD> This section requires SIPs to provide for establishing and operating ambient air quality monitors, collecting, and analyzing ambient air quality data, and upon request, to make these data available to EPA. Submission of annual monitoring network plans (AMNP) consistent with EPA's ambient air monitoring regulations at 40 CFR 58.10 is one way of satisfying requirements ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 49k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━