# Air Plan Approval; Ohio; Ohio Permit Rules Revisions
**AGENCY:**
Environmental Protection Agency (EPA).
**ACTION:**
Proposed rule.
**SUMMARY:**
The Environmental Protection Agency (EPA) is proposing to approve revisions to Ohio air permitting rules into the State Implementation Plan (SIP) under the Clean Air Act (CAA). These revisions represent changes to the air permitting rules the Ohio Environmental Protection Agency (Ohio EPA) adopted on March 1, 2023, and July 25, 2025, which became effective at the State level on March 11, 2023, and August 14, 2025, respectively. These revisions will result in consistent requirements of rules at both the State and Federal level.
**DATES:**
Comments must be received on or before February 9, 2026.
**ADDRESSES:**
Submit your comments, identified by Docket ID No. EPA-R05-OAR-2025-0143 at *https://www.regulations.gov,* or via email to *[email protected].* For comments submitted at *Regulations.gov* , follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from the docket. EPA may publish any comment received to its public docket. Do not submit to EPA's docket at *https://www.regulations.gov* any information you consider to be Confidential Business Information (CBI), Proprietary Business Information (PBI), 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 ( *i.e.,* on the web, cloud, or other file sharing system). For additional submission methods, please contact the person identified in the *FOR FURTHER INFORMATION CONTACT* section. For the full EPA public comment policy, information about CBI, PBI, or multimedia submissions, and general guidance on making effective comments, please visit *https://www.epa.gov/dockets/commenting-epa-dockets.*
**FOR FURTHER INFORMATION CONTACT:**
Skyler Sanderson, Air and Radiation Division (AR-18J), Environmental Protection Agency, Region 5, 77 West Jackson Boulevard, Chicago, Illinois 60604, (312) 886-4454, *[email protected].* The EPA Region 5 office is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding Federal holidays.
**SUPPLEMENTARY INFORMATION:**
Throughout this document whenever “we,” “us,” or “our” is used, we mean EPA.
**I. Background**
On March 19, 2025, Ohio EPA submitted revisions to rules in Ohio Administrative Code (OAC) chapter 3745-31 Permit-to-Install New Sources and Permit-to-Install and Operate Program to EPA to amend the Ohio SIP. The submittal includes revisions to air permitting rules which update definitions, provisions for permit exemptions and permits-by-rule, and permit expiration timing. Ohio adopted revisions to these rules on March 11, 2023.
On August 5, 2025, Ohio EPA submitted further revisions to OAC chapter 3745-31-03. These revisions clarify the conditions for four permit exemption categories. Ohio EPA adopted these revisions on July 25, 2025.
In the March 19, 2025, and August 5, 2025, submittals, Ohio EPA requested that the following paragraphs be excluded from approval into the SIP: OAC 3745-31-01(A)(8), (E)(3)(b)(ii) and (iii), (M)(10)(a)(ii), (P)(12), (Q), and (S)(11); 3745-31-03(B)(1)(p); 3745-31-05(E); 3745-31-13(H)(1)(c); 3745-31-22(A)(3)(b); 1-hour NO <sub>2</sub> SIL in 3745-31-23(A); 3745-31-24(F); 3745-31-26(D); 3745-31-27(A)(1)(b); and 3745-31-34(B), (C), and (D).
Section 110(l) of the CAA states that a SIP revision cannot be approved if the revision would interfere with any applicable requirements concerning attainment and reasonable further progress toward attainment of a National Ambient Air Quality Standards (NAAQS) or any other applicable requirement of the CAA. Based on the information in the submittals, these revisions are not expected to negatively impact air quality or interfere with any applicable CAA requirement.
**II. Review of State Submittal**
The following discussion summarizes the rule revisions and EPA's analysis of them under the CAA.
**A. OAC 3745-31-01 Definitions**
Ohio EPA changed the numbering system for the definitions in this rule to reflect the letters of the alphabet in order to streamline future additions or deletions. This rule is now organized with definitions in sections (A) through (Z) and reference materials in section (AA). Ohio EPA also changed references to these definitions throughout this chapter in order to align with the new numbering system.
Ohio EPA added the definition of “Carbon Dioxide (CO <sub>2</sub> ) Equivalent” under OAC 3745-31-01(C)(1) to replace similar language in OAC 3745-31-34.
Ohio EPA added the definition of “Greenhouse gases” under OAC 3745-31-01(G)(4) to replace similar language in OAC 3745-31-34.
Ohio EPA clarified the definition of “Sum of the difference” for New Source Review projects under OAC 3745-31-01(M)(3)(c)(iv).
Ohio EPA reworded the definition of “Non-road engine” under OAC 3745-31-01(N)(9) [formerly OAC 3745-31-01(CCCC)] in order to be consistent with Federal regulations.
Ohio EPA moved the definition of “Reasonable possibility” to OAC 3745-31-01(R)(2) from OAC 3745-31-10(A)(6).
Ohio EPA updated references to the Code of Federal Regulations and United States Code under OAC 3745-31-01(AA)(2) in order to reflect the most recent editions. Ohio EPA added references to 40 CFR 60.18, 60.4214, 60.4243, 60.4245, 63.6585, 63.6650, 80.510, and 40 CFR part 60 subpart JJJ to this section.
EPA finds these revisions approvable because they provide clarity to terms used in various rules throughout the SIP and do not change the requirements of the rules themselves.
**B. OAC 3745-31-02 Applicability, Requirements, and Obligations**
OAC 3745-31-02 contains provisions requiring sources of air pollution to obtain an installation permit. Ohio EPA modified the rule to clarify that provisions for permits-by-rule are now located in OAC 3745-31-30.
**C. OAC 3745-31-03 Exemptions**
OAC 3745-31-03 contains provisions for sources that qualify for permit exemptions. This rule relieves exempt sources from the obligation to apply for and obtain a construction permit but does not exempt any source from CAA requirements. Previous provisions for permits-by-rule are now located in OAC 3745-31-30.
The rule revisions change the following permanent exemptions under OAC 3745-31-03(B)(1):
(l): Storage tanks. In subparagraph (i), pertaining to inorganic liquids, a reference to paragraph (B)(1)(m)(vii) has been corrected to read (B)(1)(l)(vii).
(u): Very small municipal waste combustion units. These units are subject to the 40 CFR part 60 subparts EEEE and FFFF and are title V sources by definition, thus they cannot be exempted. The text of this paragraph has been removed and replaced with “reserved.”
(pp): Two-stroke or four-stroke air-cooled gasoline powered engines of no more than twenty horsepower. Natural gas and liquified propane gas will be allowable fuels, as well as gasoline.
(tt): One-time use of a mobile treatment unit or vacuum truck. Under (ii), references to (B)(1)(b), (B)(2)(d) and (B)(2)(e) have been corrected to refer to paragraphs (C)(1)(b), (C)(2)(d) and (C)(2)(e), respectively, under the newly created OAC 3745-31-30.
In addition, the rule revisions add the following new permanent exemptions under OAC 3745-31-03(B)(1):
(kkk): Valve sites and metering and regulating facilities within the natural gas transmission and downstream distribution pipeline system that have a potential to emit of less than 5.0 tons of VOC per year.
(lll): Temporary portable flares used in conjunction with on-site repairs, maintenance, or construction/dismantlement of pipelines used for transmission or downstream distribution of natural gas, butane, or similar liquified petroleum gas, that are not located at well sites or natural gas processing facilities and are operated in accordance with 40 CFR 60.18 and process no more than 14,000.0 million British thermal units of gas per year.
(mmm): Temporary fuel-burning equipment ( *e.g.,* boilers or engines) used to replace main fuel-burning equipment during periods of maintenance or repair provided the actual emissions and hourly potential to emit of the temporary sources do not exceed that of the replaced sources, the temporary source does not remain at the location for more than ninety consecutive days, and the owner or operator has notified the director prior to the sources use. This exemption does not apply to sources subject to the portable source requirements under paragraph (B)(1)(p) of this rule.
(nnn): Breweries of beer and flavored malt beverages breweries, including packaging and labeling lines. Production capacity may not exceed 60,000 31-gallon barrels per year.
(ooo): Portable sawmills which process no more than five million board feet of green wood per year, are powered by exempt non-road engines, and where wood waste is mechanically discharged directly to storage piles.
(ppp): Sand and gravel storage and handling operations that process no more than 125,000 tons of sand and gravel combined per year. This does not include roadways and parking areas at these operations.
(qqq): Wet cooling towers, treatment systems for process cooling water or boiler feedwater, and water tanks, reservoirs, or other water containers designed to cool, store, or otherwise handle water (including rainwater). Included in the exemption are water-handling equipment not subject to Federal NESHAPs, with no direct contact with certain chemical agents, and with a predicted particulate drift below a certain threshold.
(rrr): Animal crematories that process no more than 600 pounds per hour of whole animals and bedding, with the presence of infectious and zoonotic agents prohibited, and which only supply natural gas, propane, or butane to the burners, and does not employ liquid accelerants.
(sss): Production electric arc welding operations that use no more than 116 pounds of electrode per day.
(ttt): Ultraviolet type or corona discharge type ozone generators with maximum output capacity not exceeding 189 grams of ozone per hour.
The submittal states these new permanent exemptions would not have an adverse impact on emissions or air quality. Sources meeting the criteria for these exemptions are low-emitting sources which would not have required a permit to construct or operate prior to this revision. Some would have been considered “de minimis” sources in accordance with OAC 3745-15-05. The remaining sources would not have been permitted in accordance with Ohio EPA's interpretation of OAC 3745-31 rule requirements. These source categories were included as explicit exemptions to provide clarity to small businesses in determining if air permits are required for their operations. A quantitative analysis showed that each qualifying source in these exempt categories would emit no more than 5.0 tons per year of any pollutant. In addition, if these sources were required to obtain a permit, it would not result in further controls or emissions reductions beyond the conditions to meet the exemption. The rule also does not interfere with any other applicable CAA requirement, including the applicability of other SIP requirements, and those found in the New Source Performance Standards and the National Emission Standards for Hazardous Air Pollutants. EPA agrees with Ohio's justifications and proposes to find these revisions approvable.
**D. OAC 3745-31-05 Criteria for Decision by the Director**
OAC 3745-31-05 identifies criteria used in issuing an installation permit. This rule revision contains the following changes:
Ohio EPA added language to OAC 3745-31-05(A)(3)(a)(i) to clarify that a source may be subject to Best Available Technology (BAT) requirements if it has been modified on or after January 1, 1974.
Ohio EPA modified a table in OAC 3745-31-05(I) in order to reflect changes in divisional responsibilities when the Ohio EPA Air Division must coordinate its review of certain types of permits.
EPA finds these revisions approvable as they are clarifications that do not affect the requirements of the rule.
**E. OAC 3745-31-07 Termination, Revocation, Expiration, Renewal, Revision and Transfer**
OAC 3745-31-07 contains provisions on the termination, revocation, expiration, renewal, revision and transfer of air permits. Ohio EPA added two provisions under OAC 3745-31-07(A)(1) to modify the requirement that an installation permit terminate after eighteen months. If the permit is subject to an appeal by a party other than the owner or operator, the time period may be extended. If the permit has been superseded by a subsequent permit, the existing permit will be terminated.
40 CFR part 52 describes Federal guidelines for approval and promulgation of SIPs. 40 CFR 52.21(r) “Source obligation”, describes source obligations to construct within 18 months of receiving approval to construct, but the Administrator may extend this period “upon a satisfactory showing that an extension is justified”. In keeping with these guidelines, the revisions to OAC 3745-31-07 clarify situations that Ohio EPA deems “justified” to grant an extension. These situations include the source undertaking a continuing program of construction during the 18-month period; the source entering into a binding contractual obligation to undertake and complete a continuing program of construction; the source requesting and receiving an extension from the director of the date by which the source must be constructed per an administrative modification; or the construction permit being subject to a third-party appeal. Under this last situation, the 18-month construction deadline would be paused during the appeal until it is fully resolved, at which time the deadline would resume.
Ohio EPA issued an engineering guide, posted on its website, on October 31, 2025, detailing the process the agency will follow when a construction permit is appealed. This includes notifying interested parties of the appeal and that the permit's construction period will be paused until the appeal is resolved. Ohio EPA will also assess any changes in air quality or Federal standards that occurred since the appeal was filed, such as newly constructed nearby emissions sources, changes in the NAAQS, or changes to applicable New Source Performance Standards or National Emission Standards for Hazardous Air Pollutants, and review any submitted air quality modeling to ensure it meets current requirements. If the modeling review shows issues, the Permittee will be notified and required to adjust their permit application to meet relevant requirements and submit revised modeling.
EPA finds these revisions approvable as they are protective of the NAAQS, ensure the public is adequately informed of the permitting process, and do not contravene any CAA requirement.
**F. OAC 3745-31-06 Through 3745-31-29**
The following rules were revised with minor formatting changes for clarification and citation corrections:
• 3745-31-06 Completeness determinations, processing requirements, public participation, public notice, and issuance
• 3745-31-09 Variances on operation
• 3745-31-10 NSR projects at existing emissions units at a major stationary source
• 3745-31-11 Attainment provisions—ambient air increments, ceilings and classifications
• 3745-31-12 Attainment provisions—data submission requirements
• 3745-31-13 Attainment provisions—review of major stationary sources and major modifications, stationary source applicability and exemptions
• 3745-31-14 Attainment provisions—preapplication analysis
• 3745-31-15 Attainment provisions—control technology review
• 3745-31-16 Attainment provisions—major stationary source impact analysis
• 3745-31-17 Attainment provisions—additional impact analysis
• 3745-31-18 Attainment provisions—air quality models
• 3745-31-19 Attainment provisions—notice to the United States environmental protection agency
• 3745-31-20 Attainment provisions—innovative control technology
• 3745-31-21 Nonattainment provisions—review of major stationary sources and major modifications—stationary source applicability and exemptions
• 3745-31-22 Nonattainment provisions—conditions for approval
• 3745-31-23 Nonattainment provisions—stationary sources locating in designated clean or unclassifiable areas which would cause or contribute to a violation of a national ambient air quality standard
• 3745-31-24 Nonattainment provisions—baseline for determining credit for emission and air quality offsets
• 3745-31-25 Nonattainment provisions—location of offsetting emissions
• 3745-31-26 Nonattainment provisions—offset ratio requirements
• 3745-31-27 Nonattainment provisions—administrative procedures for emission offsets
• 3745-31-28 Review of major stationary sources of hazardous air pollutants requiring MACT determinations
• 3745-31-29 General permit-to-install and general PTIO
EPA finds these revisions approvable as they are clarifications and corrections that do not affect the requirements of the rules.
**G. OAC 3745-31-30 Permits-by-Rule**
OAC 3745-31-30 contains provisions for sources that qualify for permits-by-rule (PBR). These provisions were previously under OAC 3745-31-03, but Ohio EPA has separated these provisions into their own rule for simplicity.
The following changes to the original OAC 3745-31-03 language are being made:
Ohio added OAC 3745-31-30(B), stating the relocation of a portable PBR source is exempt under OAC 3745-31-03, provided the requirements of OAC 3745-31-03(B)(1)(p) are met.
Ohio added the word “reciprocating” to OAC 3745-31-30(C)(2)(a) to clarify that combustion turbines are excluded.
Ohio deleted redundant language in OAC 3745-31-30(C)(2)(c)(iii).
Ohio corrected citations in OAC 3745-31-30(C)(2)(l).
Ohio added a new “transloader” PBR to OAC 3745-31-30(C)(2)(n) to address portable belt or screw conveyor devices used to transfer bulk material between trucks and railcars.
Ohio added a new “petroleum-solvent dry cleaner” PBR to OAC 3745-31-30(C)(2)(o) to address small and medium-sized dry-cleaning establishments that use non-perchloroethylene solvents.
EPA finds these revisions approvable as they are clarifications and corrections that do not affect the requirements of the rule, and the new PBRs are modifications of the mechanism for permitting and do not impact emissions or air quality. PBRs include the applicable emission limits, control requirements, operational restrictions, monitoring, recordkeeping, and reporting requirements that would go into a traditional permit.
**H. OAC 3745-31-32 Plantwide Applicability Limit**
This rule contains provisions for sources that choose to be covered under a plantwide applicability limit (PAL).
Ohio modified OAC 3745-31-32(A)(4) to reflect the exemption from BAT requirements described in OAC 3745-31-05(A)(3)(a)(iv) for PALs. EPA finds these revisions approvable as they are clarifications that do not affect the requirements of the rule.
**III. What action is EPA taking?**
EPA is proposing to approve Ohio EPA's March 19, 2025, and August 5, 2025, submittals as revisions to its existing SIP. EPA finds that the revisions are consistent with Federal requirements. As requested by Ohio EPA, the following provisions are not included in this proposed approval: OAC 3745-31-01(A)(8), (E)(3)(b)(ii) and (iii), (M)(10)(a)(ii), (P)(12), (Q), and (S)(11); 3745-31-03(B)(1)(p); 3745-31-05(E); 3745-31-13(H)(1)(c); 3745-31-22(A)(3)(b); 1-hour NO <sub>2</sub> SIL in 3745-31-23(A); 3745-31-24(F); 3745-31-26(D); 3745-31-27(A)(1)(b); and 3745-31-34(B), (C), and (D).
**IV. Incorporation by Reference**
In this rulemaking, EPA is proposing to include in a final EPA rule regulatory text that includes incorporation by reference. In accordance with requirements of 1 CFR 51.5, EPA is proposing to incorporate by reference Ohio rule(s) 3745-31-01 [with the exception of OAC 3745-31-01(A)(8), (E)(3)(b)(ii) and (iii), (M)(10)(a)(ii), (P)(12), (Q), and (S)(11)], 3745-31-02, 3745-31-03 [with the exception of OAC 3745-31-03(B)(1)(p)], 3745-31-05 [with the exception of OAC 3745-31-05(E)], 3745-31-06, 3745-31-07, 3745-31-09, 3745-31-10, 3745-31-11, 3745-31-12, 3745-31-13 [with the exception of OAC 3745-31-13(H)(1)(c)], 3745-31-14, 3745-31-15, 3745-31-16, 3745-31-17, 3745-31-18, 3745-31-19, 3745-31-20, 3745-31-21, 3745-31-22 [with the exception of OAC 3745-31-22(A)(3)(b)], 3745-31-23 [with the exception of the 1-hour NO <sub>2</sub> SIL in 3745-31-23(A)], 3745-31-24 [with the exception of OAC 3745-31-24(F)], 3745-31-25, 3745-31-26 [with the exception of OAC 3745-31-26(D)], 3745-31-27 [with the exception of OAC 3745-31-27(A)(1)(b)], 3745-31-28, 3745-31-29, 3745-31-30, and 3745-31-32, effective March 11, 2023, and August 14, 2025, discussed in section II of this preamble. EPA has made, and will continue to make, these documents generally available through *www.regulations.gov* and at the EPA Region 5 Office (please contact the person identified in the *FOR FURTHER INFORMATION CONTACT* section of this preamble for more information).
**V. Statutory and Executive Order Reviews**
Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the CAA and applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to approve State choices, provided that they meet the criteria of the CAA. Accordingly, this action merely approves State law as meeting Federal requirements and does not impose additional requirements beyond those imposed by State law. For that reason, this action:
• Is not a significant regulatory action subject to review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993);
• Is not subject to Executive Order 14192 (90 FR 9065, February 6, 2025) because SIP actions are exempt from review under Executive Order 12866;
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 *et seq.* );
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 *et seq.* );
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Does not have federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Is not subject to Executive Order 13045 (62 FR 19885, April 23, 1997) because it approves a State program;
• Is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001); and
• Is not subject to requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the Clean Air Act.
In addition, the SIP is not approved to apply on any Indian reservation land or in any other area where EPA or an Indian Tribe has demonstrated that a Tribe has jurisdiction. In those areas of Indian country, the rulemaking does not have Tribal implications and will not impose substantial direct costs on Tribal governments or preempt Tribal law as specified by Executive Order 13175 (65 FR 67249, November 9, 2000).
**List of Subjects in 40 CFR Part 52**
Environmental protection, Air pollution control, Carbon monoxide, Incorporation by reference, Intergovernmental relations, Lead, Nitrogen dioxide, Ozone, Particulate matter, Reporting and recordkeeping requirements, Sulfur oxides, Volatile organic compounds.
Dated: December 23, 2025.
Cheryl Newton,
Acting Regional Administrator, Region 5.