The Air and Waste Management Association – Upper Midwest Section recently hosted the 40th annual Conference on the Environment (COE). Trinity Consultants participated in the planning and presentations associated with this conference. Here are some key takeaways from this year’s conference!

Conference Takeaways

MPCA’s Year in Review

Each year at COE, the Minnesota Pollution Control Agency (MPCA) presents an update on the agency’s progress from the past year and goals for the coming year. Topics included the lowering of the annual National Ambient Air Quality Standard (NAAQS) for PM2.5 from 12 µg/m3 to 9 µg/m3, updates on Air Toxics reporting and regulation, updates on the Cumulative Impacts regulation, and a brief discussion of the state Odor regulation.

Current monitoring data shows the state of Minnesota is in attainment with the lowered PM2.5 NAAQS standard. However, the margin between current background data and the new standard is narrow, making passing air dispersion modeling challenging in certain areas of the state.

Facilities with an air permit are required to submit an annual air emission inventory. Starting in reporting year 2026, facilities in the 7-county metro area will also need to report air toxics emissions annually. MPCA is also working to finalize the proposed Air Toxics regulations, which will be drafted by May 18, 2026.

The pending Cumulative Impacts regulation will require a cumulative impacts analysis when permitting in locations within a certain distance of environmental justice areas. If the analysis does not yield passing results, the permitting project will either not move forward, or it will require a community benefit agreement to be reached with the local community prior to proceeding with the project. MPCA is working to present a draft of the regulation on May 18, 2026.

Lastly, the agency mentioned that an Odor regulation is in the beginning stages of development but does not have a set timeline yet.

MPCA Modeling Update

The MPCA’s modeling update built on their presentation last year where they introduced their new modeling policy. The agency introduced two new forms, the CH-19 and CH-20 form, which allow permittees to determine whether their project requires permitting depending on the project emission increases. There were no substantial changes to the policy, but a few updates were announced:

• Update to the CH-19 form

• PM10 and PM2.5 thresholds are now based on a lb/day rate, as opposed to a lb/hr rate. The rates were scaled up from the previous lb/hr threshold.

• There is an additional question now asking whether any new limits were proposed such that emission increases were below the threshold.

• There is additional clarification for how to request a determination from the agency to exclude an emergency generator from modeling.

• Update to the CH-20 form

• There is now an additional question requesting if a pollutant is currently monitored by an MPCA-approved monitor at a permittee’s facility.

• Future changes

• The MPCA is currently exploring a quantitative process to exclude an emergency generator from modeling, as opposed to the current process, which involves requesting a determination from the agency.

• The MPCA also clarified that this process will not apply other intermittent sources.

The MPCA also discussed certain scenarios where a permittee could submit a permit applicability determination to avoid modeling even if project emission increases are greater than the threshold. This could include whether a facility is near an MPCA monitor or results from a previous modeling demonstration.

Upcoming Federal (De)Regulations – What Might and Might Not Be Finalized!

Tony Colombari presented on numerous upcoming regulations that are expected to reduce the compliance burden for industrial facilities. This included a discussion of the following EPA plans:

• The repeal of the greenhouse gas (GHG) mandatory reporting rule (MRR) – EPA has proposed to repeal the GHG MRR for all sources other than certain sources in Subpart W. The remaining Subpart sources would be granted a 10-year delay in reporting. This is expected to be finalized; but may be reinstated by future administration.

• The planned rescinding of the greenhouse gas (GHG) endangerment finding – EPA is proposing to rescind the GHG endangerment finding that was the basis of regulating GHG under the Clean Air Act. This is expected to be difficult for EPA to implement as it will face swift legal challenges likely to lead to the Supreme Court.

• The raising of the PM2.5 Annual National Ambient Air Quality Standard (NAAQS) – EPA is proposing to either rescind the 2024 standard (reverting back to 12 µg/m3) or to reconsider the standard, likely setting it somewhere between 9 and 12 µg/m3. The EPA is hoping to make this change in advance of the attainment/nonattainment designations required by February of 2026.

EPA is considering numerous other changes, such as repealing or reconsidering federal standards under 40 FR Part 60 and Part 63 and revising guidance for permitting under the PSD program.

SPCC & SWPPP: Tips and Tricks

Russell Novotny discussed agency guidance and common issue that trip up facilities with their Stormwater Pollution Prevention Plan (SWPPP) and Spill Pollution Control and Countermeasure (SPCC) Plan.

Key to Compliance: Oil/Chemical Inventory = Site Plan = Inspection Schedule

• Ensure SPCC Plan and SWPPP are accurate

• Oil Inventory (indoors and outdoors)

• Include outdoor materials in SWPPP

• Secondary containment correctly identified

• Site Maps

• Create an effective SPCC Plan and SWPPP

• Comprehensive inspection and training programs

• Easy-to-follow spill response and reporting procedures

• Design for a sustainable SPCC Plan and SWPPP

• Consolidate requirements into comprehensive tables

• Identify ongoing compliance requirements (inspections, integrity testing, monitoring, training, etc.)

• Request editable documents from contractors/consultants

• Review Annually

How Temporary Air Monitors Can Help Your Facility

John Ke presented on temporary air monitors and their benefits. With lower standards, higher background concentrations, outdated and overly conservative emission factors, and more industrial sources popping up every day, it is becoming increasingly challenging to find ways to demonstrate compliance with ambient air quality thresholds using just air dispersion modeling to move forward with your projects. More facilities are now choosing to demonstrate compliance with ambient air quality standards through air quality monitors rather than modeling. These are permanent units at a facility that can provide ground-truth monitoring data. However, monitoring units are expensive and require monthly and quarterly maintenance checks.

As opposed to permanent monitors, temporary monitors can serve as a useful tool for facilities considering using air quality monitors to demonstrate compliance with ambient air quality standards. They also have other uses that can assist with modeling demonstrations. For more information on temporary monitors, check out our recent article.

Keep Your Cool with the New HFC Management Rule

Jena DeRung discussed 40 CFR 84 Subpart C, Management of Regulated Substances, which was published on October 11, 2024, and describes requirements for appliances containing refrigerants. A regulated substance is a hydrofluorocarbon (HFC) listed in the American Innovation and Manufacturing (AIM) Act. 40 CFR 84 Subpart C specifies requirements for repairing appliances containing more than 15 pounds of regulated substances and substitutes1, in addition to the installation of automatic leak detection systems (ALDS) on commercial and industrial system with more than 1,500 pounds of refrigerants containing regulated substances and substitutes. Compliance with the 40 CFR 84 Subpart C leak repair procedures, reporting and recordkeeping requirements is required by January 1, 2026. Compliance with ALDS requirements begins January 1, 2026, for new appliances and January 1, 2027, for existing appliances. Trinity has created a tool, CoolTracker365™, which maintains documentation of the requirements under this subpart in one spreadsheet.

If you have any questions about the Conference on the Environment or the topics presented, please contact Tony Colombari, Russell Novotny, John Ke, or Jena DeRung.