U.S. EPA’s Guideline on Air Quality Models Final Rule Revised

On November 20, 2024, the U.S. EPA Administrator signed a final rule revising the Guideline on Air Quality Models (Appendix W to 40 CFR Part 51). The Guideline defines EPA-recommended models and techniques for predicting ambient concentrations of air pollutants. Guidance for use of these models is also provided in the document. This final action includes several technical enhancements to the AERMOD dispersion modeling system:

• Inclusion of the RLINE mobile source type as a regulatory default option,
• Elevation of the Generic Reaction Set Method (GRSM) for NOx to NO2 conversion as a Tier 3 selection, and
• Parameterization of marine boundary layer environments for offshore sources via the COARE algorithms.

These updates also includes a new guidance document for developing background concentrations for modeling demonstrations.

Full details of the final rule including technical support material and responses to all comments received during the rule proposal stage can be found on the EPA’s website.

U.S. EPA Updates AERMOD Modeling System to 24142

Concurrent to U.S. EPA’s approval of updates to the Guideline on Air Quality Models, the U.S. EPA published updates to the AERMOD Modeling System as version 24142. The updates include new versions of AERMOD, AERMET, AERMAP, AERSURFACE, AERPLOT, and the MMIF prognostic meteorological data utility.

Details of the release and lists of important changes can be found in the release memorandum on the EPA website. Major changes to AERMOD include the elevation to regulatory default status of the RLINE source type, GRSM NO2 conversion method, & COARE overwater processing algorithm.

A full list of changes for each model or tool can be found on their respective web pages: AERMOD, AERMET, AERMAP, AERSURFACE, and MMIF web pages. These updates immediately replace prior releases as the official regulatory versions of the applications. Using the latest models is important for many reasons:

• Ensures calculations are performed according to current state-of-science algorithms.
• Keeps facilities in compliance by using approved model versions.
• Allows modelers to test and provide vital feedback on new model options that will shape the future of air modeling.

See our Modeling Tip below for additional information about how these changes impact the popular AERMOD View & AERMET View applications.

A&WMA “Guideline on Air Quality Models: A New Chapter” Conference Wrap-Up

Earlier this month, Lakes Environmental was proud to sponsor the Air & Waste Management Specialty Conference: “Guideline on Air Quality Models: A New Chapter”. The conference was also sponsored by the A&WMA Technical Coordinating Committee for Atmospheric Modeling and Meteorology (APM) and was held November 13-15 at the Sheraton Raleigh Hotel in downtown Raleigh, NC. Over 100 people attended, and we enjoyed meeting the attendees!

Lakes’ Senior Meteorologist, Michael Hammer, served as the General Conference Chair. The conference featured an opening keynote plenary session with staff from the U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards who offered updates on regulatory modeling development priorities. This was followed by over 35 technical presentations covering a wide range of topics such as ozone and fine particulate analyses, modeling for environmental justice impacts, recent updates to the AERMOD modeling system, NO2 techniques, mobile source modeling, unique case studies, and more.

If you missed us at this conference, check our Upcoming Conferences listing below for other opportunities to meet Lakes Environmental including the A&WMA 118th Annual Conference and Exhibition taking place June 9-12, 2025 in Raleigh, NC!

Online AERMOD Training Course – Jan 7-8, 2025 - 4 Spots Left!

Don’t miss out on our next available 2-day online AERMOD training course taking place on January 7 and 8, 2025, from 8:30am to 5:00pm (Central Time – Chicago, USA).

Register today before space is gone!

Note: Due to the immense popularity of our online courses and small class sizes, we recommend registering and making payment as soon as possible to reserve your spot.

Online CALPUFF Training Course – Jan 21-22, 2025 - 4 Spots Left!

Our next available 2-day online CALPUFF training course is almost full! Join us on January 21 and 22, 2025, for a comprehensive, hands-on learning experience, from 8:30am to 5:00pm (Central Time – Chicago, USA).

Don't be left out! Register today!

Course:

CALPUFF (Feb 25-28, 2025)

Contact:

casanz@casanz.org.au

Updates to AERMOD View & AERMET View

As described above, the U.S. EPA has been busy this month! Major updates to the Guideline on Air Quality Models and associated changes to the AERMOD Modeling System mean that Lakes Environmental will be very busy in the coming weeks as we update AERMOD View & AERMET View to incorporate the new models. These changes take on many forms:

• Inclusion of new model executables into each application (AERMOD & AERMAP into AERMOD View, AERMET & AERSURFACE into AERMET View)
• Development of new parallelized AERMOD MPI model
• Incorporating new features corresponding to each model release
• Updating existing model functionality (e.g., elevation of RLINE, GRSM, & COARE to work with AERMOD’s regulatory default mode)
• Ensuring all aspects of the models are handled with 100% accuracy
• Updating documentation
• And more!

We anticipate that our updates will be completed in December 2024. Be on the lookout for email communication from Lakes Environmental announcing the availability of the new AERMOD View and AERMET View releases.

If your copy of AERMOD View is no longer in maintenance, please contact our sales team at sales@webLakes.com for pricing to update your software.

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