Minnesota Pollution Control Agency Issues Draft Second Phase of Air Toxics Regulations

The Minnesota Pollution Control Agency (MPCA), on May 18, 2026, published draft rules to implement the second phase of 2023 legislation regulating air toxic emissions from permitted facilities in the seven-county Twin Cities metropolitan area. The proposal would amend existing air permitting rules in Minnesota Rules chapter 7007 and create a new chapter 7012 establishing screening, risk-analysis, compliance, notification and emissions-reduction requirements for affected sources. As proposed, the rules would impose substantial new analytical and compliance obligations on many permitted facilities and mark a significant expansion of Minnesota’s air toxics regulatory framework.

Background

The Minnesota Legislature, in 2023, passed two pieces of legislation regarding air toxics emissions. The first, codified at Minn. Stat. § 116.062, addresses how owners and operators of facilities with an air quality permit in the seven counties surrounding Minneapolis and St. Paul must report their facilities’ annual air toxics emissions. On November 6, 2025, the Minnesota Pollution Control Agency commissioner published the final version of rules governing the emissions reporting process. See MPCA Adopts Air Toxics Reporting Rules, But Governor Vetoes Emergency Affirmative Defense Repeal.

The second piece of legislation, Minnesota Session Law - 2023, Chapter 60, article 8, section 5 (H.F. No. 2310), directs the MPCA commissioner to adopt rules regulating air toxic emissions themselves. The Legislature mandated that the rules, at a minimum, specify the air toxics to be regulated, acceptable tests for measuring the air toxics emissions, and the types of facilities subject to the requirements, i.e., those with air quality permits (with certain exceptions) in the seven-county metro area.

Highlights of the Proposed Rules

The MPCA commissioner published a draft of the air toxics rules in the Minnesota State Register on May 18, 2026, the same day she published proposed cumulative impact/environmental justice area rules affecting many of these same permitted facilities. See Minnesota Pollution Control Agency Releases Long-Awaited Draft “Cumulative Impact” Rules for Minnesota’s “Environmental Justice” Areas. The proposed rules incorporate air toxic emission considerations throughout existing rules governing air permits in Minn. R. Ch. 7007. More importantly, they create a new regulatory chapter — 7012 — devoted exclusively to the regulation of air toxic emissions. Many of the requirements included in the new proposed chapter track requirements previewed by the MPCA in the years leading up to the proposed chapter’s publication. Those requirements include, among other things:

• Exemption by Permit Type (7012.0060): Facilities with registration option A or B permits or with nonmetallic mineral processing general permits that are in compliance with their respective chapter 7007 requirements are exempt from the requirements of chapter 7012. Those with registration option C permits are also exempt, provided they can certify they emit air toxics only from indirect heating units and those emissions do not stem from the use of VOC-containing materials.
• Air Toxics Screening Threshold Analysis (7012.0150): Owners or operators of applicable facilities must keep hourly and annual emissions at or below screening threshold values, perform the required analysis, and certify the results unless they are already completing a risk analysis or compliance determination protocol (CDP). If an existing facility exceeds those thresholds, the owner or operator must either prepare a CDP or complete an air emissions risk analysis (AERA). A new permit application for a facility expected to exceed the thresholds, however, will be required to complete an AERA.
  • Exemption; Air Emissions Risk Analysis In lieu of Screening Threshold Analysis (7012.0070): An owner or operator of a facility may request an exemption from completing a screening threshold analysis (STA) if the owner or operator completes an AERA that satisfies the requirements of item B. Requests must be made at least 60 days before the deadline for submitting an STA, and the commissioner must deny the request if it is incomplete or does not satisfy the item B criteria.

• Additional Screening Threshold Analysis (7012.0170): The MPCA commissioner must order an additional STA when new information, facility changes, updated standards, risk-based data, relocation or missing prior records suggest possible screening threshold value exceedances. If the commissioner issues written notice, the owner or operator must submit the analysis’s certification within 60 days, but the owner or operator also may respond within 10 days with additional information the commissioner may not have considered prior to the notice. Finally, the facility may lose its exemption eligibility under proposed rule 7012.0070 if the new analysis shows the facility exceeds screening threshold values.
• Air Toxics Screening Threshold Analysis; Method of Calculating Emissions (7012.0400): Owners and operators of facilities must calculate emissions for the STA using recent actual annual emissions, current stack or fugitive-source parameters, and specified methods for hourly emission rates, as set forth in the proposed rule. It also lists exempted emission units, including certain emergency or insignificant sources, certain comfort-heating equipment and hazardous air pollutant emissions already regulated under Clean Air Act section 112(d), but still requires non-hazardous air toxic emissions still be counted.
• Compliance Determination Protocol (7012.0450): An owner or operator whose facility exceeds screening threshold values and is not submitting an AERA protocol must submit a CDP showing how emissions will be reduced to or below those thresholds. The proposed rule also establishes a CDP’s contents, filing deadline, compliance timeline, monitoring and recordkeeping requirements, and semiannual deviation reporting obligations.
  • Owners or operators that cannot provide evidence of remaining at or below screening threshold values by submitting a CDP must instead submit an AERA protocol. (7012.0530).

• Air Emissions Risk Analysis Protocol (7012.0550): The owner or operator of a facility emitting air toxics above screening threshold values must submit an AERA protocol for the commissioner’s approval unless it is instead submitting a CBP. The proposed rule details the operational, emissions, modeling and supporting information the protocol must include, explains how the commissioner must approve compliant protocols or give notice of and the reasons for any disapproval, and dictates resubmission of a revised protocol within 60 days of a disapproval.
• Air Emissions Risk Analysis Report (7012.0560): Owners and operators must submit an AERA report that includes, e.g., detailed risk summaries, modeling data, facility and emissions information, supporting documents, a certification and any additional materials required for special situations, such as those involving emergency engines or mercury emissions. The proposed rule sets the acceptable risk thresholds with which the analysis must show compliance, including limits for cancer risk, inhalation and multipathway hazard quotients, and noncancer hazard indices. It also allows limited use of a recent prior analysis, requires the commissioner either to approve compliant reports or explain a disapproval, mandates resubmission of a report within 60 days of disapproval, and, for certain permitted facilities, requires a major permit amendment to be submitted within 180 days after report approval.
• Notification to Potentially Impacted Residents (7012.0568): Owners and operators of facilities with risk analysis results above acceptable levels must mail commissioner-approved notices to potentially impacted residents and nearby sensitive facilities. The notices must describe the required emissions reductions, available report information, planned compliance actions and contact details, and must be sent by deadlines specified in the proposed rule.
• Air Toxics Reduction Plan; Requirements (7012.0570): Owners or operators must submit an air toxics reduction plan when a facility’s modeled impacts exceed acceptable risk levels and the facility will not submit a CDP to reduce emissions below screening thresholds. The proposed rule establishes the plan’s contents, approval and resubmittal processes, implementation, reporting requirements and permit-amendment deadlines. It also allows a CDP to be submitted instead if the facility can reduce and maintain emissions at or below screening threshold values through operational changes or restrictions.
• Ambient Air Monitoring Requirements (7012.0650): Owners and operators may only use ambient air monitoring to show compliance with chapter 7012 for facilities that meet strict eligibility conditions, such as showing an air toxics reduction plan cannot be implemented or did not achieve acceptable risk levels, and only if the facility has demonstrated the predicted maximum ambient impact exceeds acceptable risk levels, ambient air monitoring methods contribute to the exceedance, proposed air toxics have acceptable reporting limits, and the owner or operator has an approved monitoring plan. The proposed rule also delineates the requirements for the monitoring plan, the approval process and the proof needed to justify using monitoring, including monitor placement, sampling and laboratory standards, data completeness, commissioner access and explanations of why prior compliance efforts failed.

Next Steps

Members of the public may now submit comments on the draft rules until 4:30 p.m. on July 17, 2026. The MPCA also provided notice of a two-day administrative hearing on the proposed rules alongside with the publication of the proposed rules in the State Register. Administrative Law Judge James Mortenseon will conduct the virtual public hearings on October 5, 2026, at 6:30 p.m. and on October 6 beginning at 9:30 a.m. The public will have additional opportunities for comment — and the MPCA opportunities for rebuttal — following the administrative hearing.

Fredrikson attorneys Bill Hefner and Shantal Pai, along with colleagues from Trinity Consultants, will host a webinar on June 10, 2026, summarizing and analyzing the proposed rules, for those interested in learning more. Fredrikson’s Environmental team will continue to monitor and report on the development and adoption of these rules and stands ready to assist regulated parties as they navigate these and other new and existing environmental requirements across the country.

For more information or questions, contact Bill Hefner.