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Proposed Rule

Air Plan Approval; Iowa; Revisions to Iowa Air Quality Regulations

A Proposed Rule by the Environmental Protection Agency on 03/26/2026

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3. Document Details Published Content - Document Details Agency Environmental Protection Agency Agency/Docket Numbers EPA-R07-OAR-2026-1156 FRL-13242-01-R7 CFR 40 CFR 52 40 CFR 70 Document Citation 91 FR 14658 Document Number 2026-05875 Document Type Proposed Rule Pages 14658-14666 (9 pages) Publication Date 03/26/2026 Published Content - Document Details

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• Document Details Published Content - Document Details Agency Environmental Protection Agency Agency/Docket Numbers EPA-R07-OAR-2026-1156 FRL-13242-01-R7 CFR 40 CFR 52 40 CFR 70 Document Citation 91 FR 14658 Document Number 2026-05875 Document Type Proposed Rule Pages 14658-14666 (9 pages) Publication Date 03/26/2026 Published Content - Document Details
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  • AGENCY:
  • ACTION:
  • SUMMARY:
  • DATES:
  • ADDRESSES:
  • FOR FURTHER INFORMATION CONTACT:
  • SUPPLEMENTARY INFORMATION:
  • Table of Contents
  • I. Written Comments
  • II. What is being addressed in this document?
  • III. What SIP revisions are being proposed by the EPA?
  • A. Revisions to the Iowa SIP
  • B. EPA Analysis of SIP Revisions
  • IV. What Operating Permit Program plan revisions are being proposed by the EPA?
  • V. Have the requirements for approval of a SIP and the Operating Permit Program plan revisions been met?
  • VI. CAA 110(k)(6) Error Correction
  • A. Background
  • B. Analysis of IAC 567—Chapter 27—Certificate of Acceptance
  • C. Analysis of IAC 567—Subrule 22.1(3)“b”(8)—Application for a Case-by-Case MACT Determination
  • D. Analysis of IAC 567—Subrule 25.1(12)—Alternative Emission Control Program Trade Off Sulfur Dioxide CEMS Requirements
  • E. Analysis of IAC 567—Subrule 23.1(1)—In General
  • F. Section 193 “Anti-Backsliding” Analysis
  • VII. What action is the EPA taking?
  • VIII. Incorporation by Reference
  • IX. Statutory and Executive Order Reviews
  • List of Subjects
  • 40 CFR Part 52
  • 40 CFR Part 70
  • PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS
  • Subpart Q—Iowa
  • PART 70—STATE OPERATING PERMIT PROGRAMS
  • Appendix A to Part 70—Approval Status of State and Local Operating Permits Programs
  • Iowa
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Environmental Protection Agency

1. 40 CFR Parts 52 and 70
2. [EPA-R07-OAR-2026-1156; FRL-13242-01-R7]

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

The Environmental Protection Agency (EPA) is proposing to approve revisions to the Iowa State Implementation Plan (SIP) and the Operating Permit Program to incorporate recent changes to the Iowa Administrative Code (IAC). The revisions include removal of the Voluntary Operating Permit Program language; removal of the Emission Reduction Program language; new and renumbered rules; replacement of duplicative language with references to state statute and federal regulations; updated definitions; consolidation of 14 chapters into 8 chapters; and minor clarifications to language and grammar. The EPA is also proposing to correct the erroneous incorporation of several rules into the Iowa SIP pursuant to section 110(k)(6) of the Clean Air Act (CAA). These revisions do not decrease the stringency of the SIP or have an adverse effect on air quality. The EPA's proposed approval of this rule revision is in accordance with the requirements of the CAA.

DATES:

Comments must be received on or before April 27, 2026.

ADDRESSES:

You may send comments, identified by Docket ID No. EPA-R07-OAR-2026-1156 to https://www.regulations.gov. Follow the online instructions for submitting comments.

Instructions: All submissions received must include the Docket ID No. for this rulemaking. Comments received will be posted without change to https://www.regulations.gov, including any personal information provided. For detailed instructions on sending comments and additional information on the rulemaking process, see the “Written Comments” heading of the SUPPLEMENTARY INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT:

Allyson Prue, Environmental Protection Agency, Region 7 Office, Air Quality Planning Branch, 11201 Renner Boulevard, Lenexa, Kansas 66219; telephone number: (913) 551-7277; email address: prue.allyson@epa.gov.

SUPPLEMENTARY INFORMATION:

Throughout this document “we,” “us,” and “our” refer to the EPA.

Table of Contents

I. Written Comments

II. What is being addressed in this document?

III. What SIP revisions are being proposed by the EPA?

IV. What Operating Permit Program plan revisions are being proposed by the EPA?

V. Have the requirements for approval of a SIP and the Operating Permit Program Plan revisions been met?

VI. CAA 110(k)(6) Error Correction

VII. What action is the EPA taking?

VIII. Incorporation by Reference

IX. Statutory and Executive Order Reviews

I. Written Comments

Submit your comments, identified by Docket ID No. EPA-R07-OAR-2026-1156, at https://www.regulations.gov. Once submitted, comments cannot be edited or removed from Regulations.gov. The EPA may publish any comment ( printed page 14659) 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 (i.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 https://www.epa.gov/​dockets/​commenting-epa-dockets.

II. What is being addressed in this document?

The EPA is proposing to approve revisions to the Iowa SIP and Title V Operating Permit Program received on July 26, 2024. All revisions were completed due to a new administrative process required by Executive Order 10 (E.O.-10), issued by the Iowa Governor in January 2023. The revisions are to section 567—Iowa Air Quality Regulations. The revisions to the Iowa SIP and Title V Operating Permit Program are specified in sections III.-IV. below. Additionally, the EPA is proposing multiple CAA 110(k)(6) error corrections in this rulemaking. The full text of the rule revision as well as the EPA's analysis of the revisions can be found in the technical support documents (TSD) included in the docket for this action.

CAA sections 111 and 112 allow the EPA to delegate authority to states for New Source Performance Standards (NSPS) and National Emission Standards for Hazardous Air Pollutants (NESHAPs). The EPA has delegated authority to Iowa for approved portions of these sections of the CAA. Changes made to Iowa's Chapter 23 pertaining to new and revised NSPS and NESHAPs are not directly approved into the SIP, but rather, are adopted by reference. Thus, EPA is not proposing to approve the changes to Chapter 23 of the Iowa Administrative Code into the state's SIP.

III. What SIP revisions are being proposed by the EPA?

A. Revisions to the Iowa SIP

Iowa requested the following revisions to SIP-approved chapters:

Chapter 20—SCOPE OF TITLE—DEFINITIONS is rescinded. Most definitions previously located in this chapter have been moved to the revised Chapters 21, 22, or 23. Numerous definitions from this chapter were no longer relevant because the terms no longer appear in section 567 of the Iowa Code and were therefore deleted.

Chapter 21—COMPLIANCE is retitled COMPLIANCE, EXCESS EMISSIONS, AND MEASUREMENT OF EMISSIONS. Revisions to this chapter include the removal of the Emission Reduction Program language; adoption by reference of federal language; incorporation of rules from the now-removed Chapters 24, 25, 26, and 29; removal of numerous definitions; updated citations; and minor revisions to grammar and wording.

Chapter 22—CONTROLLING POLLUTION—PERMITS is retitled CONTROLLING AIR POLLUTION—CONSTRUCTION PERMITTING. Revisions to SIP-approved text at IAC 567-22.1 through IAC 567-22.10 and IAC 567-22.200 through IAC 567-22.209 include the removal of the Voluntary Operating Permit Program; incorporation of rules from the now-removed Chapters 20 and 28; language relocation; updated citations; and minor revisions to grammar and wording. Additionally, SIP-approved text at IAC 567-22.105(2)“i”(5) and IAC 567-22.300 were relocated to Chapter 24.

Chapter 23—EMISSION STANDARDS is retitled AIR EMISSION STANDARDS. Revisions to this chapter include removal of redundant language; updated citations; and minor revisions to grammar and wording.

Chapter 24—EXCESS EMISSIONS is retitled OPERATING PERMITS. This chapter incorporates two SIP-approved sections from the former Chapter 22. The SIP-approved sections are located in IAC 567-24.105(2)“i”(5) and IAC 567-24.300 in the submitted revisions. Revisions to SIP-approved sections are administrative in nature and include updated citations and minor revisions to grammar and wording.

Chapter 25—MEASUREMENT OF EMISSIONS is rescinded. IAC 567-25.1 was previously SIP approved and is relocated to the new Chapter 21, with the exception of IAC 567-25.1(12), which retains its SIP approval.

Chapter 26—PREVENTION OF AIR POLLUTION EMERGENCY EPISODES is rescinded. All sections were previously SIP approved and are relocated to the new Chapter 21, where they retain SIP approval.

Chapter 28—AMBIENT AIR QUALITY STANDARDS is rescinded. IAC 567-28.1 of this chapter was previously SIP approved and is relocated to the revised Chapter 21, where it retains its SIP approval.

Chapter 29—QUALIFICATIONS IN VISUAL DETERMINATION OF THE OPACITY OF EMISSIONS is rescinded. IAC 567-29.1 of this chapter was previously SIP approved and is relocated to the revised Chapter 21, where it retains its SIP approval.

Chapter 31—NONATTAINMENT AREAS is retitled NONATTAINMENT NEW SOURCE REVIEW. Revisions to this chapter include the removal of language referencing nonattainment areas, because Iowa no longer has any areas designated nonattainment prior to May 18, 1998; updated citations; and minor revisions to grammar and wording.

Chapter 33—SPECIAL REGULATIONS AND CONSTRUCTION PERMIT REQUIREMENTS FOR MAJOR STATIONARY SOURCES—PREVENTION OF SIGNIFICANT DETERIORATION (PSD) OF AIR QUALITY is retitled CONSTRUCTION PERMIT REQUIREMENTS FOR MAJOR STATIONARY SOURCES—PREVENTION OF SIGNIFICANT DETERIORIATION (PSD). Revisions to this chapter include numerous adoptions by reference of federal language, removal of redundant language, updated citations, and minor revisions to grammar and wording.

B. EPA Analysis of SIP Revisions

The EPA reviewed the submitted SIP revisions in accordance with the anti-backsliding provisions of CAA section 110(l). While most revisions were administrative in nature, Iowa also requested removal of the Emission Reduction Program (IAC 567-21.3) and the Voluntary Operating Permits Program (IAC 567-22.200 through IAC 567-22.209).

The EPA approved the Emission Reduction Program as part of the SIP on May 31, 1972 (37 FR 10842). The program provided a mechanism for sources to reduce emissions in exchange for a variance or for an extension of a variance granted by IDNR. The EPA finds that while IDNR removed the Emission Reduction Program from its regulations, it also strengthened its existing variance language by requiring the State to weigh the impact on public health that the variance would create versus the potential hazard to health or property that alternative methods of compliance may impact. If IDNR concludes that emissions caused by the variance would harm public health, IDNR would not grant the variance, and the removal of the Emission Reduction Program from the SIP does not impact ( printed page 14660) this analysis. In addition, the EPA notes that IDNR retains discretion to use existing enforcement authorities to obtain emission reductions in exchange for granting a variance. Therefore, the EPA concludes that removing the Emission Reduction Program from the SIP does not interfere with any applicable requirement concerning attainment and reasonable further progress under CAA section 110(l).

The EPA approved IDNR's voluntary operating permit (VOP) program as part of the SIP on April 30, 1996 (61 FR 18958). This program primarily served as a CAA section 112(l) mechanism to establish federally enforceable operational limits to restrict potential to emit (PTE) to avoid Title V and other major source requirements. The program also provided a mechanism to limit emissions of criteria pollutants, and the EPA approved it as part of the SIP under CAA section 110.

In 2015, IDNR removed the VOP program rules from the Iowa Administrative Code because it determined that the construction permit program could provide a mechanism to issue synthetic minor permits. Prior to removing VOP program rules, IDNR either modified construction permits or issued new construction permits for VOP facilities, as necessary, as described in the “Voluntary Operating Permit Background and Summary” document in the docket for this rulemaking.

The VOP program is not a required program under CAA section 110. The EPA finds that Iowa's Chapter 22 construction permit rules provide adequate authority for limiting a source's PTE of criteria pollutants to below major source thresholds. As such, Iowa's removal of the VOP regulations from the SIP does not interfere with any applicable requirement concerning attainment and reasonable further progress under CAA section 110(l).

IV. What Operating Permit Program plan revisions are being proposed by the EPA?

The EPA is proposing the following revisions to the Operating Permit Program:

Chapter 22—CONTROLLING POLLUTION—PERMITS is retitled CONTROLLING AIR POLLUTION—CONSTRUCTION PERMITTING. Revisions to IAC 567-22.2 and IAC 567-22.3(6) include language relocation, updated citations, and minor revisions to grammar and wording. IAC 567-22.100 through IAC 567-22.300 were relocated to Chapter 24. Finally, numerous definitions from IAC 567-22.1 and IAC 567-22.10(1) are retained in the Title V Operating Permit Program.

Chapter 23—EMISSION STANDARDS is retitled AIR EMISSION STANDARDS. Iowa has requested the EPA approve the definitions at IAC 567-23.1(4) into the Title V Operating Permit Program. The terms were previously approved into the Title V Operating Permit Program but were relocated to IAC 567-23.1(4).

Chapter 24—EXCESS EMISSIONS is retitled OPERATING PERMITS. This chapter incorporates the operating permit rules from the former Chapter 22. Revisions to this chapter include removal of the Voluntary Operating Permit Program language; numerous adoptions by reference of federal language; removal of redundant language and of provisions requiring that copies of Title V operating permit applications be submitted to EPA Region 7; updated citations; and minor revisions to grammar and wording. As discussed in section III. of this proposed rule, the VOP Program is not a required program of the Title V Operating Permit Program.

Chapter 30—FEES is retained. Revisions to this chapter include addition of clarifying language, removal of redundant language, and updated citations.

V. Have the requirements for approval of a SIP and the Operating Permit Program plan revisions been met?

The State submission has met the public notice requirements for SIP submissions in accordance with 40 CFR 51.102. The submission also satisfied the completeness criteria of 40 CFR part 51, appendix V. The State provided public notice on this SIP revision from December 27, 2023, to January 30, 2024, and received no comments. In addition, as explained above and in more detail in the technical support documents which is part of this document, the revision meets the substantive SIP requirements of the CAA, including section 110 and implementing regulations.

VI. CAA 110(k)(6) Error Correction

A. Background

A SIP is a federally enforceable collection of regulations and documents used by a state, territory, or local air district to implement, maintain, and enforce the National Ambient Air Quality Standards (NAAQS) and to fulfill other requirements of the CAA that require SIP measures (e.g., measures addressing regional haze under CAA section 169A). The NAAQS addresses six criteria pollutants: carbon monoxide, nitrogen dioxide, ozone, lead, particulate matter, and sulfur dioxide. Each federally approved SIP protects air quality primarily by addressing air pollution at its point of origin through air pollution regulations and control strategies.

CAA section 110(k)(6), authorizes the EPA, when it “determines that [its] action approving, disapproving, or promulgating any plan or plan revision (or part thereof) . . . was in error,” to “revise such action as appropriate.” CAA section 110(k)(6) provides the EPA with the authority to make corrections to prior SIP actions that are subsequently found to be in error in the same manner as the prior action and do so without requiring any further submission from the state. While section 110(k)(6) provides the EPA with the authority to correct its own “error,” nowhere does this provision or any other provision in the CAA define what qualifies as “error.” Thus, the term should be given its ordinary meaning. See Johnson v. United States, 559 U.S. 133, 138 (2010). The plain language, every day meaning of “error” encompasses all unintentional, incorrect or wrong actions or mistakes; see Error, MERRIAM-WEBSTER'S COLLEGIATE DICTIONARY (11th ed. 2004) (“an act that through ignorance, deficiency, or accident departs from or fails to achieve what should be done”).

In this rulemaking, the EPA proposes to remove IAC 567—Chapter 27, IAC 567—Subrule 23.1(1), IAC 567—Subrule 22.1(3)“b”(8), and IAC 567-Subrule 22.7(2)“f” from the Iowa SIP under CAA section 110(k)(6). On November 19, 2025, Iowa concurred with removal of these provisions. Because Iowa agrees with the EPA that these chapters were approved into the SIP in error, the EPA interprets the state's concurrence as a withdrawal of Iowa's request that the EPA approve revisions to these chapters into the SIP.

The EPA determined during its review of this rulemaking that these four rules were inappropriate for inclusion into the SIP because they are not related to implementation, maintenance, or enforcement of the NAAQS or otherwise required by the CAA to be included in the SIP. The analysis of each provision proposed for removal from Iowa's SIP is discussed below and in the TSDs for this action.

B. Analysis of IAC 567—Chapter 27—Certificate of Acceptance

Congress enacted the CAA in 1970. CAA section 110(a)(1) requires each state to submit a SIP to the EPA that provides for the implementation, maintenance and enforcement of the NAAQS. In the 1970s and early 1980s, ( printed page 14661) state and local agencies submitted thousands of regulations to the EPA for inclusion in SIPs to meet new federal requirements. In many cases, states submitted entire air pollution program regulations, including many elements not required by the CAA. Due to time and resource constraints, the EPA's review of these submittals focused primarily on the rules addressing the new substantive requirements of the CAA, and we approved many other elements into the SIP with minimal review. We now recognize that some of these elements are appropriate for state and local agencies to adopt and implement, but not as federally enforceable SIP requirements.

Chapter 27—Certificate of Acceptance [1 ] was first approved into the Iowa SIP on May 31, 1972 (37 FR 10842). The EPA approved subsequent administrative revisions on September 12, 1985 (50 FR 37176) and June 29, 1990 (55 FR 26690). Chapter 27 provides political subdivisions, such as municipalities and counties, with the conditions necessary to obtain and maintain a certificate of acceptance issued by the state for a local air pollution control program. This chapter is administrative in nature, and includes requirements related to the local agency's legal authority, enforcement program, staffing requirements, office space, staff transportation, and control program activities.

The Linn County and Polk County local air programs are currently the only two local air programs in Iowa with certificates of acceptance issued under the authority of IAC 567—Chapter 27. Each county implements its own air pollution control ordinances, and is responsible for inspections of facilities, tracking emissions data, air quality monitoring, and compliance at major and minor facilities within its area of jurisdiction. The state retains concurrent enforcement authority. Iowa submits each county's air pollution control ordinances to the EPA for approval into the SIP. The EPA first approved Linn County's air pollution control ordinances into the Iowa SIP on August 15, 1989 (54 FR 33526) and has approved subsequent revisions, with the most recent revision approved on July 1, 2023 (89 FR 54362). The EPA first approved a portion of Polk County's air pollution ordinances into the Iowa SIP on August 15, 1989 (54 FR 33528), subsequently approving most of the remaining ordinances on November 29, 1989 (56 FR 60924). The most recent revision to Polk County's air pollution ordinances was approved on September 21, 2021 (86 FR 52413).

Pursuant to 40 CFR 51.232, a state may assign legal authority to carry out the state implementation plan within a local agency's jurisdiction if the plan demonstrates that the local agency has the necessary legal authority to carry out the plan. The state provides this demonstration in an infrastructure SIP submission which provides the necessary structural requirements for each new or revised NAAQS. The EPA's most recent approval of Iowa's demonstration that its local agencies have the legal authority to carry out the SIP appears in EPA's August 23, 2021, approval of Iowa's infrastructure SIP for the 2015 ozone NAAQS. See 86 FR 46984.

EPA's approval of county air quality ordinances into the SIP does not depend on whether a county has a certificate of acceptance from the state. Furthermore, EPA's approval of the state's infrastructure SIP submission does not depend on whether a local agency has obtained a certificate of acceptance issued under Chapter 27. Therefore, the EPA proposes to remove Chapter 27 from the Iowa SIP because the EPA approved Chapter 27 in error and it is not required by the CAA for implementation, maintenance, or enforcement of the NAAQS.

C. Analysis of IAC 567—Subrule 22.1(3)“b”(8)—Application for a Case-by-Case MACT Determination

During the review of this rulemaking, the EPA determined that IAC 567-22.1(3)“b”(8)— Application for a case-by-case MACT determination -be removed from the Iowa SIP. This subrule was approved into the Iowa SIP on December 3, 1999 (64 FR 67784). IAC 567-22.1(3)“b”(8) provides the requirements for sources to apply for a case-by-case maximum achievable control technology (MACT) determination in a construction permit application for the construction or reconstruction of a major source of hazardous air pollutants. Case-by-case MACT determinations are required by CAA section 112(j) and 40 CFR part 63, subpart B if EPA misses the deadline for promulgating a section 112(d) standard by more than 18 months. Accordingly, the EPA is proposing to remove IAC 567-22.1(3)“b”(8) from the Iowa SIP because it relates to section 112 requirements and the control of air toxics rather than criteria pollutants and is therefore not required by the CAA for implementation, maintenance, or enforcement of the NAAQS.

D. Analysis of IAC 567—Subrule 25.1(12)—Alternative Emission Control Program Trade Off Sulfur Dioxide CEMS Requirements

During its review of this rulemaking, the EPA determined that IAC 567-25.1(12) was approved into the Iowa SIP in error on September 12, 1985 (50 FR 37176). IAC 567-25.1(12) requires sources with an approved alternative emission control program under IAC 567-22.7(1) that involves the trade-off of sulfur dioxide emissions to install, calibrate, maintain and operate a continuous emissions monitoring system (CEMS) for sulfur dioxide. At the time that the EPA approved IAC 567-25.1(12) into the SIP, IAC 567-22.7(1) was not part of the SIP, and has not been subsequently approved. Therefore the requirement for a source with an approved alternative emission control program to operate a sulfur dioxide CEMs was not an enforceable requirement of the SIP.

Iowa moved the requirements of IAC 567-25.1(12) to IAC 567-22.7(2)“f”. Accordingly, EPA is proposing to remove IAC 567-25.1(12) from the SIP because it was not an enforceable requirement of the SIP and is therefore not required by the CAA for implementation, maintenance, or enforcement of the NAAQS.

E. Analysis of IAC 567—Subrule 23.1(1)—In General

In its July 16, 2024, submittal, Iowa excluded its revision to IAC 567-23.1(1) from the SIP. IAC 567-23.1(1) states that the NSPS shall apply as specified in IAC 567-23.1(2), which is not approved into the SIP. In addition, the rule states that the NESHAPs shall apply as specified in IAC 567-23.1(3), which is not approved into the SIP. Finally, the rule requires compliance with all other emission standards to be in accordance with Chapter 21—Compliance, a chapter which is approved into the SIP, and does not rely on IAC 567-23.1(1) in order to be enforceable.

During its review of this rulemaking, the EPA determined that IAC 567-23.1(1) was approved into the Iowa SIP in error on May 31, 1972 (37 FR 10842). This subrule is a general provision that pertains to federal standards, such as the NSPS and NESHAPs, and requires compliance with regulations that are not approved into the SIP. Iowa requests delegation of certain NSPS and NESHAPs under a delegation agreement with the EPA. [2 ] For these reasons, the ( printed page 14662) EPA is proposing to remove IAC 567-23.1(1) from the Iowa SIP because it is not required by the CAA for implementation, maintenance, or enforcement of the NAAQS.

F. Section 193 “Anti-Backsliding” Analysis

CAA section 193 provides that, for SIP control requirements in effect before November 15, 1990, any “modification” thereof must “insure[ ] equivalent or greater emissions reductions” of the air pollutant for which the area is in nonattainment. 42 U.S.C. 7515. Congress added this provision in the 1990 Amendments as part of an effort to ensure adequate support for NAAQS attainment and maintenance. Consistent with the provision's plain text, Congress' intent in adopting this provision was to provide a `back-up' anti-backsliding provision for nonattainment areas beyond what was provided by 110(l). [3 ] As a general matter, this “anti-backsliding” analysis is required when modifying SIP control requirements, whether through section 110(k)(6) or otherwise, if the modification impacts pre-1990 control requirements in a nonattainment area.

All areas of Iowa are designated in attainment or maintenance of each NAAQS. See 40 CFR 81.316. As a result, the EPA's proposed removal of the above rules from the Iowa SIP is not subject to the general savings clause in CAA section 193.

VII. What action is the EPA taking?

The EPA is proposing to amend the Iowa SIP and Title V Operating Permit Program by approving the State's request to revise section 567, Title II—Iowa Air Quality Regulations. In addition, the EPA is proposing to remove IAC 567—Chapter 27, IAC 567-22.1(3)“b”(8), IAC 567-23.1(1), and IAC 567-25.1(12) from the Iowa SIP under the authority of CAA section 110(k)(6) because EPA's previous approval of these rules into the Iowa SIP was in error. We are processing this as a proposed action because we are soliciting comments on this proposed action. The EPA is soliciting comment on the substantive and administrative revisions detailed in this proposal and the TSD. The EPA is not soliciting comment on existing rule text that has been previously approved by the EPA into the SIP. Final rulemaking will occur after consideration of any comments.

VIII. Incorporation by Reference

In this document, the EPA is proposing to include regulatory text in an EPA final rule that includes incorporation by reference. In accordance with requirements of 1 CFR 51.5, and as discussed in section III. of this preamble, the EPA is proposing the incorporation by reference of section 567, Title II of the Iowa Air Quality Administrative Regulations, which regulates air quality in the state of Iowa:

• Chapter 21—Compliance, Excess Emissions, and Measurement of Emissions, which provides provisions for air quality compliance, excess emissions, and measurement of emissions;
• Chapter 22—Controlling Air Pollution, which provides provisions for air quality construction permitting as well as applicable air quality definitions;
• Chapter 23—Air Emission Standards, which provides provisions for air emission standards as well as applicable air quality definitions;
• Chapter 24—Operating Permits, which includes provisions for Title V Operating Permits, Acid Rain Permits, and Small Source Operating Permits;
• Chapter 30—Fees, which defines specific air quality fees owed by air contaminant sources;
• Chapter 31—Nonattainment New Source Review, which provisions for the preconstruction review and permitting program applicable to new or modified major sources of air pollutants in areas that do not meet the National Ambient Air Quality Standards (NAAQS); and
• Chapter 33—Construction Permit Requirements for Major Stationary Sources—Prevention of Significant Deterioration (PSD), which provides provisions for the preconstruction permitting program applicable to new or modified major stationary sources of air pollutants. The EPA is also proposing to remove rules that were previously incorporated by reference from the Iowa SIP. In accordance with the requirements of 1 CFR 51.5, the EPA is proposing to remove IAC 567—Chapter 27, IAC 567-22.1(3)“b”(8), IAC 567-23.1(1), and IAC 567-25.1(12) discussed in section VI. of this preamble and as set forth below in the proposed revision to 40 CFR part 52.

The EPA has made, and will continue to make, these materials generally available through https://www.regulations.gov and at the EPA Region 7 Office (please contact the person identified in the FOR FURTHER INFORMATION CONTACT section of this preamble for more information).

IX. 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 Orders 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 CAA. 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 rule 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).

( printed page 14663)

List of Subjects

40 CFR Part 52

• Environmental protection
• Air pollution control
• Incorporation by reference
• Intergovernmental relations
• Particulate matter
• Reporting and recordkeeping requirements
• Volatile organic compounds

40 CFR Part 70

• Environmental protection
• Administrative practice and procedure
• Air pollution control
• Intergovernmental relations
• Operating permits
• Reporting and recordkeeping requirements Dated: March 13, 2026.

James Macy,

Regional Administrator, Region 7.

For the reasons stated in the preamble, the EPA proposes to amend 40 CFR parts 52 and 70 as set forth below:

PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

1. The authority citation for part 52 continues to read as follows:

Authority: 42 U.S.C. 7401 et seq.

Subpart Q—Iowa

1. In § 52.820, in the table in paragraph (c):

a. Remove the center heading “Chapter 20—Scope of Title—Definitions” and the entries “567-20.1”, “567-20.2”, and “567-20.3”.

b. Revise the center heading “Chapter 21—Compliance” to read “Chapter 21—Compliance, Excess Emissions, and Measurement of Emissions” and the entries “567-21.1”, “567-21.2”, “567-21.3”, “567-21.4”, “567-21.5”, and “567-21.6” and add the entries “567-21.7”, “567-21.8”, “567-21.10”, “567-21.13”, “567-21.14”, “567-21.15”, “567-21.16”, and “567-21.17”.

c. Revise the center heading “Chapter 22—Controlling Pollution” to read “Chapter 22—Controlling Air Pollution” and the entries “567-22.1”, 567-22.2”, “567-22.3”, 567-22.4”, “567-22.5”, “567-22.8”, “567-22.9”, and “567-22.10”; add the entry “567-22.11”; and remove the entries “567-22.105”, “567-22.200”, “567-22.201”, “567-22.202”, “567-22.203”, “567-22.204”, “567-22.205”, “567-22.206”, “567-22.207”, “567-22.208”, “567-22.209”, and “567-22.300”.

d. Revise the center heading “Chapter 23—Emission Standards for Contaminants” to read “Chapter 23-Air Emission Standards” and the entries “567-23.1”, “567-23.2”, “567-23.3”, and “567-23.4”.

e. Revise the center heading “Chapter 24—Excess Emissions” to read “Chapter 24-Operating Permits”; remove the entries “567-24.1” and 567-24.2”; and add the entries “567-24.105” and “567-24.300”.

f. Remove the center heading “Chapter 25—Measurement of Emissions” and the entry “567-25.1”.

g. Remove the center heading “Chapter 26—Prevention of Air Pollution Emergency Episodes” and the entries “567-26.1”, “567-26.2”, “567-26.3”, and “567-26.4”.

h. Remove the center heading “Chapter 27—Certificate of Acceptance” and the entries “567-27.1”, “567-27.2”, “567-27.3”, “567-27.4”, and “567-27.5”.

i. Remove the center heading “Chapter 28—Ambient Air Quality Standards” and the entry “567-28.1”.

j. Remove the center heading “Chapter 29—Qualification in Visual Determination of the Opacity of Emissions” and the entry “567-29.1”.

k. Revise the center heading “Chapter 31—Nonattainment Areas” to read “Chapter 31—Nonattainment New Source Review” and the entries “567-31.1”, “567-31.3”, “567-31.4”, “567-31.9”, and “567-31.10” and remove entries “567-31.2 and 567-31.20”.

l. Revise the center heading “Chapter 33—Special Regulations and Construction Permit Requirements for Major Stationary Sources—Prevention of Significant Deterioration (PSD) of Air Quality” to read “Chapter 33-Construction Permit Requirements for Major Stationary Sources—Prevention of Significant Deterioration (PSD)” and the entries “567-33.1”, “567-33.3”, “567-33.9”, and 567-33.10”.

The revisions and additions read as follows:

§ 52.820 Identification of plan. * * * * * (c) * * *

| Iowa citation | Title | State
effective
date | EPA approval date | Explanation |
| --- | --- | --- | --- | --- |
| Iowa Department of Natural Resources Environmental Protection Commission [567] | | | | |
| | | | | |
|                                                       * | | | | |
| Chapter 21—Compliance, Excess Emissions, and Measurement of Emissions | | | | |
| 567-21.1 | Definitions and compliance requirements | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.2 | Variances | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.4 | Circumvention of rules | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.5 | Evidence used in establishing that a violation has occurred or is occurring | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| ( printed page 14664) | | | | |
| 567-21.6 | Temporary electricity generation for disaster situations | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.7 | Excess emission reporting | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.8 | Maintenance and repair requirements | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.10 | Testing and sampling of new and existing equipment | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.13 | Methodology and qualified observer | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.14 | Prevention of air pollution emergency episodes—general | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.15 | Episode criteria | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.16 | Preplanned abatement strategies | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-21.17 | Actions taken during episodes | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| Chapter 22—Controlling Air Pollution | | | | |
| 567-22.1 | Definitions and permit requirements for new or existing stationary sources | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | The definitions for “anaerobic lagoon,” “odor,” “odorous substance,” “odorous substance source” are not SIP approved. |
| 567-22.2 | Processing permit applications | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-22.3 | Issuing permits | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | Subrule 22.3(6) is not SIP approved. |
| 567-22.4 | Major stationary sources located in areas designated attainment or unclassified (PSD) | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-22.5 | Major stationary sources located in areas designated nonattainment | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-22.8 | Permit by rule | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-22.9 | Special requirements for visibility protection | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| ( printed page 14665) | | | | |
| 567-22.10 | Permitting requirements for country grain elevators, country grain terminal elevators, grain terminal elevators and feed mill equipment | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-22.11 | Ambient air quality standards | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| Chapter 23—Air Emission Standards | | | | |
| 567-23.1 | Emission standards | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | Subrules 23.1(1)-(5) are not SIP approved. |
| 567-23.2 | Open burning | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | Subrule 23.2(3)j is not SIP approved. Variances from opening burning rule 23.2(2) are subject to EPA approval. |
| 567-23.3 | Specific contaminants | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | Subrule 23.3(3)“(d)” is not SIP approved. |
| 567-23.4 | Specific processes | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | Subrule 23.4(10) is not SIP approved. |
| Chapter 24—Operating Permits | | | | |
| 567-24.105 | Title V permit applications | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | Only subparagraph 24.105(2)i(5) is SIP approved. |
| 567-24.300 | Operating permit by rule for small sources | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| Chapter 31—Nonattainment New Source Review | | | | |
| 567-31.1 | Permit requirements relating to nonattainment area | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-31.3 | Nonattainment new source review (NNSR) requirements for areas designated nonattainment | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-31.4 | Preconstruction review permit program | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-31.9 | Actuals PALs | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-31.10 | Validity of rules | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| Chapter 33—Construction Permit Requirements for Major Stationary Sources—Prevention of Significant Deterioration (PSD) | | | | |
| 567-33.1 | Purpose | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| ( printed page 14666) | | | | |
| 567-33.3 | PSD construction permit requirements for major stationary sources | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | Provisions of the 2010 PM 2.5 PSD-Increments, SILs, and SMCs rule are excluded from 33.3(20) and are not SIP approved. |
| 567-33.9 | Plantwide applicability limitations | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| 567-33.10 | Exceptions to adoption by reference | 6/19/2024 | [Date of publication of the final rule in the Federal Register ], 91 FR [Federal Register page where the document begins of the final rule] | |
| | | | | |
|                                                       * | | | | |

---

PART 70—STATE OPERATING PERMIT PROGRAMS

1. The authority citation for part 70 continues to read as follows:

Authority: 42 U.S.C. 7401, et seq.

1. Appendix A to part 70 is amended by adding paragraph (aa) under “Iowa” to read as follows:

Appendix A to Part 70—Approval Status of State and Local Operating Permits Programs

---

Iowa

• * * * * (aa) The Iowa Department of Natural Resources submitted for program approval revisions to rules 567—Chapter 22 and 567-30.4 on July 26, 2024. Rules 567-22.100 through 567-22.300(12) are now located in Chapter 24 and are referred to as 567-24.100 through 567-24.300(12). Rules 567-22.117 through 567-22.119 (now 567-24.117 through 567-24.119) as well as rules 567-22.210 through 567-22.299 (now 567-24.210 through 567-24.299) remain reserved and are not part 70 approved. Previously part 70 approved rules 567-22.200 through 567-22.209 (now 567-24.200 through 567-24.209) have been reserved as a part of this approval and are no longer part 70 approved. Revisions were also made to rule 567-30.4. Numerous definitions located in 576-22.1, 567-22.10(1), and 567-23.1(4) retain part 70 approval. The state effective date is June 19, 2024. The proposed revision effective date is [date 30 days after date of publication of the final rule in the Federal Register ].

---

Footnotes

1.

                     Iowa's Certificate of Acceptance regulations were initially codified in Chapter 3 of the Iowa Administrative Code air regulations.

Back to Citation 2.

                     See *[https://www.epa.gov/​ia/​delegation-authority-iowa-new-source-performance-standards-and-national-emission-standards](https://www.epa.gov/ia/delegation-authority-iowa-new-source-performance-standards-and-national-emission-standards).*

Back to Citation 3. See, e.g., Senate Debate on the 1990 Amendments to the CAA Conference Report (Oct. 26, 1990), 1990 CAA Legis. Hist. 1097, 1126-1127 (Comments of Senator Chafee, R-RI, primary drafter of CAA Amendments of 1990).

Back to Citation [FR Doc. 2026-05875 Filed 3-25-26; 8:45 am]

BILLING CODE 6560-50-P

Published Document: 2026-05875 (91 FR 14658)