    [Federal Register Volume 91, Number 58 (Thursday, March 26, 2026)]
    [Proposed Rules]
    [Pages 14658-14666]
    From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
    [FR Doc No: 2026-05875]

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    ENVIRONMENTAL PROTECTION AGENCY

    40 CFR Parts 52 and 70

    [EPA-R07-OAR-2026-1156; FRL-13242-01-R7]

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

    AGENCY: Environmental Protection Agency (EPA).

    ACTION: Proposed rule.

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    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

    [[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

    [[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,

    [[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.
    ---------------------------------------------------------------------------

        \1\ Iowa's Certificate of Acceptance regulations were initially
    codified in Chapter 3 of the Iowa Administrative Code air
    regulations.
    ---------------------------------------------------------------------------

        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

    [[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.
    ---------------------------------------------------------------------------

        \2\ See https://www.epa.gov/ia/delegation-authority-iowa-new-source-performance-standards-and-national-emission-standards.
    ---------------------------------------------------------------------------

    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.
    ---------------------------------------------------------------------------

        \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).
    ---------------------------------------------------------------------------

        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).

    [[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

    0
    1. The authority citation for part 52 continues to read as follows:

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

    Subpart Q--Iowa

    0
    2. In Sec.  52.820, in the table in paragraph (c):
    0
    a. Remove the center heading ``Chapter 20--Scope of Title--
    Definitions'' and the entries ``567-20.1'', ``567-20.2'', and ``567-
    20.3''.
    0
    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''.
    0
    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''.
    0
    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''.
    0
    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''.
    0
    f. Remove the center heading ``Chapter 25--Measurement of Emissions''
    and the entry ``567-25.1''.
    0
    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''.
    0
    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''.
    0
    i. Remove the center heading ``Chapter 28--Ambient Air Quality
    Standards'' and the entry ``567-28.1''.
    0
    j. Remove the center heading ``Chapter 29--Qualification in Visual
    Determination of the Opacity of Emissions'' and the entry ``567-29.1''.
    0
    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''.
    0
    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:

    Sec.  52.820  Identification of plan.

    * * * * *
        (c) * * *

                                              EPA-Approved Iowa Regulations
    ----------------------------------------------------------------------------------------------------------------
                                                            State
           Iowa citation                 Title            effective      EPA approval date          Explanation
                                                             date
    ----------------------------------------------------------------------------------------------------------------
                     Iowa Department of Natural Resources Environmental Protection Commission [567]
    ----------------------------------------------------------------------------------------------------------------

                                                      * * * * * * *
    ----------------------------------------------------------------------------------------------------------------
                         Chapter 21--Compliance, Excess Emissions, and Measurement of Emissions
    ----------------------------------------------------------------------------------------------------------------
    567-21.1..................  Definitions and            6/19/2024  [Date of publication    ......................
                                 compliance                            of the final rule in
                                 requirements.                         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           6/19/2024  [Date of publication    ......................
                                 establishing that a                   of the final rule in
                                 violation has occurred                the Federal
                                 or is occurring.                      Register], 91 FR
                                                                       [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].

    [[Page 14664]]

    567-21.6..................  Temporary electricity      6/19/2024  [Date of publication    ......................
                                 generation for                        of the final rule in
                                 disaster situations.                  the Federal
                                                                       Register], 91 FR
                                                                       [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].
    567-21.7..................  Excess emission            6/19/2024  [Date of publication    ......................
                                 reporting.                            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     6/19/2024  [Date of publication    ......................
                                 requirements.                         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    6/19/2024  [Date of publication    ......................
                                 new and existing                      of the final rule in
                                 equipment.                            the Federal
                                                                       Register], 91 FR
                                                                       [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].
    567-21.13.................  Methodology and            6/19/2024  [Date of publication    ......................
                                 qualified observer.                   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          6/19/2024  [Date of publication    ......................
                                 pollution emergency                   of the final rule in
                                 episodes--general.                    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       6/19/2024  [Date of publication    ......................
                                 strategies.                           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       6/19/2024  [Date of publication    ......................
                                 episodes.                             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     6/19/2024  [Date of publication    The definitions for
                                 requirements for new                  of the final rule in    ``anaerobic lagoon,''
                                 or existing stationary                the Federal             ``odor,'' ``odorous
                                 sources.                              Register], 91 FR        substance,''
                                                                       [Federal Register       ``odorous substance
                                                                       page where the          source'' are not SIP
                                                                       document begins of      approved.
                                                                       the final rule].
    567-22.2..................  Processing permit          6/19/2024  [Date of publication    ......................
                                 applications.                         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    Subrule 22.3(6) is not
                                                                       of the final rule in    SIP approved.
                                                                       the Federal
                                                                       Register], 91 FR
                                                                       [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].
    567-22.4..................  Major stationary           6/19/2024  [Date of publication    ......................
                                 sources located in                    of the final rule in
                                 areas designated                      the Federal
                                 attainment or                         Register], 91 FR
                                 unclassified (PSD).                   [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].
    567-22.5..................  Major stationary           6/19/2024  [Date of publication    ......................
                                 sources located in                    of the final rule in
                                 areas designated                      the Federal
                                 nonattainment.                        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       6/19/2024  [Date of publication    ......................
                                 for visibility                        of the final rule in
                                 protection.                           the Federal
                                                                       Register], 91 FR
                                                                       [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].

    [[Page 14665]]

    567-22.10.................  Permitting requirements    6/19/2024  [Date of publication    ......................
                                 for country grain                     of the final rule in
                                 elevators, country                    the Federal
                                 grain terminal                        Register], 91 FR
                                 elevators, grain                      [Federal Register
                                 terminal elevators and                page where the
                                 feed mill equipment.                  document begins of
                                                                       the final rule].
    567-22.11.................  Ambient air quality        6/19/2024  [Date of publication    ......................
                                 standards.                            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    Subrules 23.1(1)-(5)
                                                                       of the final rule in    are not SIP approved.
                                                                       the Federal
                                                                       Register], 91 FR
                                                                       [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].
    567-23.2..................  Open burning...........    6/19/2024  [Date of publication    Subrule 23.2(3)j is
                                                                       of the final rule in    not SIP approved.
                                                                       the Federal             Variances from
                                                                       Register], 91 FR        opening burning rule
                                                                       [Federal Register       23.2(2) are subject
                                                                       page where the          to EPA approval.
                                                                       document begins of
                                                                       the final rule].
    567-23.3..................  Specific contaminants..    6/19/2024  [Date of publication    Subrule 23.3(3)``(d)''
                                                                       of the final rule in    is not SIP approved.
                                                                       the Federal
                                                                       Register], 91 FR
                                                                       [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].
    567-23.4..................  Specific processes.....    6/19/2024  [Date of publication    Subrule 23.4(10) is
                                                                       of the final rule in    not SIP approved.
                                                                       the Federal
                                                                       Register], 91 FR
                                                                       [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].
    ----------------------------------------------------------------------------------------------------------------
                                              Chapter 24--Operating Permits
    ----------------------------------------------------------------------------------------------------------------
    567-24.105................  Title V permit             6/19/2024  [Date of publication    Only subparagraph
                                 applications.                         of the final rule in    24.105(2)i(5) is SIP
                                                                       the Federal             approved.
                                                                       Register], 91 FR
                                                                       [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].
    567-24.300................  Operating permit by        6/19/2024  [Date of publication    ......................
                                 rule for small sources.               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        6/19/2024  [Date of publication    ......................
                                 relating to                           of the final rule in
                                 nonattainment area.                   the Federal
                                                                       Register], 91 FR
                                                                       [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].
    567-31.3..................  Nonattainment new          6/19/2024  [Date of publication    ......................
                                 source review (NNSR)                  of the final rule in
                                 requirements for areas                the Federal
                                 designated                            Register], 91 FR
                                 nonattainment.                        [Federal Register
                                                                       page where the
                                                                       document begins of
                                                                       the final rule].
    567-31.4..................  Preconstruction review     6/19/2024  [Date of publication    ......................
                                 permit program.                       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].

    [[Page 14666]]

    567-33.3..................  PSD construction permit    6/19/2024  [Date of publication    Provisions of the 2010
                                 requirements for major                of the final rule in    PM2.5 PSD-Increments,
                                 stationary sources.                   the Federal             SILs, and SMCs rule
                                                                       Register], 91 FR        are excluded from
                                                                       [Federal Register       33.3(20) and are not
                                                                       page where the          SIP approved.
                                                                       document begins of
                                                                       the final rule].
    567-33.9..................  Plantwide applicability    6/19/2024  [Date of publication    ......................
                                 limitations.                          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     6/19/2024  [Date of publication    ......................
                                 by reference.                         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

    0
    3. The authority citation for part 70 continues to read as follows:

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

    0
    4. 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].
    * * * * *
    [FR Doc. 2026-05875 Filed 3-25-26; 8:45 am]
    BILLING CODE 6560-50-P