Air Plan Approval; Michigan; Revisions to Part 1 and 2 Rules

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R05-OAR-2022-0295; FRL-10162-06-R5]</DEPDOC> <SUBJECT>Air Plan Approval; Michigan; Revisions to Part 1 and 2 Rules</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 revisions to Michigan Air Pollution Control rules Part 2 Air Use Approval for inclusion in the Michigan State Implementation Plan (SIP). </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Comments must be received on or before May 28, 2024. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R05-OAR-2022-0295 at <E T="03">https://www.regulations.gov,</E> or via email to <E T="03">damico.genevieve@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, 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. 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://www.epa.gov/dockets/commenting-epa-dockets.</E> <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Constantine Blathras, Air Permit Section, Air Programs Branch (AR-18J), Environmental Protection Agency, Region 5, 77 West Jackson Boulevard, Chicago, Illinois 60604, (312) 886-0671, <E T="03">blathras.constantine@epa.gov.</E> The EPA Region 5 office is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding Federal holidays and facility closures due to COVID-19. </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document whenever “we,” “us,” or “our” is used, we mean EPA. <HD SOURCE="HD1">I. Background</HD> Section 110(a)(2)(C) of the Clean Air Act (CAA) requires that the SIP include a program to provide for the “regulation of the modification and construction of any stationary source within the areas covered by the plan as necessary to assure that National Ambient Air Quality Standards (NAAQs) are achieved.” This includes a program for permitting construction and modification of both major and minor sources that the state deems necessary to protect air quality. The State of Michigan's minor source permit to install rules are contained in Part 2, Air Use Approval, R. 336.1201 to R. 336.1299 of the Michigan Administrative Code. Changes to the Part 2 rules were submitted on November 12, 1993; May 16, 1996; April 3, 1998; September 2, 2003; March 24, 2009; February 28, 2017; and March 8, 2022. EPA approved changes to the Part 2 rules most recently in a final approval dated April 27, 2023 (88 FR 25498). On September 27, 2022 (87 FR 58471), EPA proposed approval, via a direct final rule, of the Michigan SIP revisions submitted on March 8, 2022. During the public comment period, EPA received an adverse comment on the Michigan rule revisions to R 336.1285 “Permit to install exemptions; miscellaneous” and R 336.1291, “Permit to install exemptions; emission units with ‘de minimis’ emissions”. On November 14, 2022 (87 FR 68634), EPA withdrew the direct final rule. EPA approved the revisions to the Michigan rule revision which did not receive adverse comment (88 FR 25498, April 27, 2023). As explained in that action, we did not consider the comments received to be germane or relevant to EPA's proposal to approve portions of Michigan's Part 1 and Part 2 rules beyond the permit exemption rules, and therefore not adverse to approving them into the Michigan SIP. EPA is now proposing to approve Michigan's rules R 336.1285(2)(oo) and R 336.1291 into the Michigan SIP. On November 14, 2023, Michigan submitted a supplement to the original March 8, 2022, submittal by supplying additional information regarding the approval of Michigan rules R 336.1285(2)(oo) and R 336.1291 in response to comments we received on the rulemaking. These rules exempt certain processes and/or equipment from Michigan's minor New Source Review permitting program. The November 14, 2023, Michigan supplemental submittal as well as the original March 8, 2022, submittal are available with the docket for this rulemaking action. <HD SOURCE="HD2">Michigan Rule R 336.1285(2)(oo)</HD> Michigan rule R 336.1285(2)(oo) exempts vapor intrusion mitigation systems. Specifically, this exemption applies to equipment or systems, or both, used exclusively to mitigate vapor intrusion of an indoor space that is not on the property where the release of the hazardous substance occurred, and which has an exhaust that meets all of the following requirements: i. Unobstructed vertically upward. ii. At least 12 inches above the nearest eave of the roof or at least 12 inches above the surface of the roof at the point of penetration. iii. More than 10 feet above the ground. iv. More than 2 feet above or more than 10 feet away from windows, doors, other buildings, and other air intakes. <HD SOURCE="HD2">Michigan Rule R 336.1291</HD> Michigan rule R 336.1291 exempts emission units with “de minimis” emissions. Specifically, rule R 336.1291 requires that records be maintained providing a description of the emission unit(s), and documentation and/or calculations identifying the quality, nature, and quantity of the air contaminant emissions are maintained in sufficient detail to demonstrate that the potential emissions are less than those listed in the table of air contaminants applicable to this exemption. Michigan's rule R 336.1291 exemption is based on the units' potential to emit. Potential to emit is defined in Michigan's rule 336.2801(hh) as: “(T)he maximum capacity of a stationary source to emit a pollutant under its physical and operational design. A physical or operational limitation on the capacity of the source to emit a pollutant, including air pollution control equipment and restrictions on hours of operation or on the type or amount of material combusted, stored, or processed, shall be treated as part of its design if the limitation or the effect it would have on emissions is legally enforceable and enforceable as a practical matter by the state, local air pollution control agency, or United States Environmental Protection Agency. Secondary emissions do not count in determining the potential to emit of a stationary source.” In Michigan's November 14, 2023, supplemental submittal, Michigan provides an analysis of the rule revisions and addresses comments raised in the October 27, 2022, letter. Michigan's analysis included responses to the commenter's points including: 1) the section 110(l) analysis must consider the program as a whole; 2) Michigan cannot rely on the Tribal rule thresholds; 3) Michigan did not demonstrate that annual potential to emit limitations sufficiently protect short-term NAAQS; 4) Michigan's justification for not having more stringent thresholds in non-attainment areas does not hold up; and 5) Michigan's representation of its actual emission exemptions are insufficient. To demonstrate that the two exemptions would not interfere with any applicable requirement concerning the attainment and reasonable further progress, or any other applicable requirement, Michigan reviewed its Michigan Air Emissions Reporting System (MAERS). The Michigan rule 291 exemption has been in effect in the state since 2016. The MAERS data contains information on a specific subset of emission units that are exempt. As described in the table of emission unit and pollutant levels for various exemptions in Michigan's supplemental submittal, of those facilities that are reporting, Michigan rule 291 emission units are responsible for less than 0.9 percent of volatile organic compound emissions from all units reported to MAERS, and less than 3.6 percent of volatile organic compound emissions from exempt units reported in MAERS. Requiring Michigan to permit these exempt units would not contribute to Michigan's plan for attainment or reasonable further progress, but would rather divert Michigan air permitting program resources from addressing other more significant air pollutant emitters. The air permit exemptions have been in effect for several years and have had no measurable impact on attainment or reasonable further progress. <HD SOURCE="HD2">Section 110(l) Demonstration</HD> As part of the SIP revision request supplemental submittal, Michigan submitted a 110(l) demonstration. Section 110(l) of the CAA governs the submittal of SIP revisions. Each revision to an implementation plan submitted by a State shall be adopted by the State after reasonable notice and public hearing. The Administrator shall not approve a revision of a plan if the revision would interfere with any applicable requirement concerning the attainment and reasonable further progress (as defined by 40 CFR 7501), or any other applicable requirement of this chapter. As part of its 110(l) demonstration, Michigan provided an analysis of the emission exemptions impacts, using the Modeled ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 21k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━