New annual PM2.5 NAAQS coming

Posted by on Tuesday, February 21st, 2023 in Newsletters

What’s Happening Now

2022 Holiday Quiz Answers

1. Our AERMOD Wizard software has a new feature that allows the user to view/work with NEI data. What does the abbreviation NEI stand for?

a. National Emissions Inventory

2. A new version of AERMOD was released by US EPA in 2022. What is the version number of this new release?

d. 22112

3. Which modeling algorithms can be used in AERMOD for estimating NO2 concentrations from total NOX emissions?


4. What EPA organization is charged with being a focal point for interpretation of modeling guidance in specific regulatory applications?

d. Model Clearinghouse

5. Finally, returning to AERMOD Wizard, which of the following air quality-related parameters cannot be viewed in AERMOD Wizard?

b. Display of Air Quality Control Regions

Thanks to everyone who played!

EPA News

As they say, this is a big one. On January 6, 2023, EPA announced that they propose to revise the annual PM2.5 National Ambient Air Quality Standard (NAAQS) downward from the current level of 12 μg/m3. Although nothing is fully decided yet, EPA indicated that they are looking at a range of from 9 to 10 μg/m3. They are not proposing to alter the 24-hour PM2.5 standard nor the 24-hour PM10 standard. Like all changes to EPA rules or NAAQS, this process will require rulemaking. EPA will propose their new annual PM2.5 NAAQS, open a comment period, hold a public hearing for also receiving comments, respond to comments and then issue a final rule. This effort will take time, so stay tuned. Check here for updates.

In the meantime, we’ve built a couple of maps showing areas of the US that would exceed the annual PM2.5 standard if it were dropped to 9 or 10 μg/m3. Click here to view the NAAQS at 10 μg/m3 or here to view the NAAQS at 9 μg/m3.

As a reminder, EPA’s triennial Conference on Air Quality Models will be coming up later this year. Keep watching here and on SCRAM for details.

Conferences and Workshops

CAPCA Spring 2023 Conference – The 2023 Spring Meeting/Conference of the Carolinas Air Pollution Control Association (CAPCA) will be held April 12‑14, 2023 at the Omni Grove Park in Asheville, NC. For more information on registration, being an exhibitor, etc. go to

TCEQ 2023 Environmental Trade Fair – The Texas Commission on Environmental Quality (TCEQ) has announced that the 2023 edition of its Environmental Trade Fair will be held May 16‑17, 2023 at the Austin (TX) Convention Center. Click here for updates and more information.

AWMA 2023 Annual Conference and Exhibition – Last but not least, Air & Waste Management Association’s (AWMA) Annual Conference and Exhibition (ACE) is coming up June 5‑8, 2023 in Orlando, FL. This year’s theme is “Smart Growth: Balancing Development, Restoration, and Resiliency”. For more information, check out We hope to see you there!

If your company, organization, agency, state, etc. has an upcoming modeling or air quality-related event (virtual or otherwise) and you’d like it publicized in Providence/Oris Notes, please send that information to us at, and we’ll be happy to include it.


BEEST 12.09 is now out and includes the following:

  • Incorporates AERMOD 22112 executable
  • AerMet GUI has been updated to run AERMET 22112

We presented a webinar on the new features in this version of BEEST on August 19, 2022. If you missed it, you can watch the recording here.

BEEST 12.10 will include support for new AERMOD 22112 keywords SWPOINT, RLINEXT, and PLATFORM. The AerMinute GUI will include download access to the new 1-minute ASOS data (as was discussed in October 2022 Providence/Oris Notes). The AerMet GUI will include support for new keywords and options, such as PROG (from MMIF).

As always, users in maintenance can download the most recent version of BEEST from Support → Software Updates.

Go BEEST Mode face masks are here! These stylish and functional masks will be the perfect complement to your Go BEEST Mode t‑shirt. These are washable/reusable and are a one size fits all. So get yours today by sending your request to

And of course, we still have plenty of Go BEEST Mode t‑shirts, too! You can also request one of those by emailing us at

If you would be interested in BEEST or AERMOD Wizard coffee mugs, let us know by emailing us at and we’ll make that happen.

AerScreen for Windows

AerScreen for Windows 4.03 is now out. This update has the following enhancements:

  • Runs AERMOD 22112
  • Includes the latest version of Terrain Files Converter

Users in maintenance can download the most recent version of AerScreen for Windows from Support → Software Updates.


AERMOD Wizard 1.08 is now out. This update has the following enhancements:

  • Download EPA monitoring data published in June 2022
  • Download raw meteorological data for Alaska and Hawaii
  • Export NEI sources, meteorological stations and monitors to Google Earth
  • New label display option for NEI sources
  • AerMet GUI has been updated to run AERMET 22112

We presented a webinar on the new features in this version of AERMOD Wizard on October 17, 2022. If you missed it, you can watch the recording here.

Users in maintenance can download the most recent version of AERMOD Wizard from Support → Software Updates.

Don’t forget – our new FREE KMZ file for monitoring stations and 2019-2021 pollutant design values is still available at

If you have suggestions for enhancements to any of our modeling software products, please let us know and we’ll do our best to incorporate them into the software.

We want to note that many folks use our classes as credit toward professional engineer continuing education requirements. Check with your state’s licensing board or the National Society of Professional Engineers (see here or here) for more information on what is required.

Essential Air Permitting

It’s back! Our latest offering focuses on everything you need to know about air permitting. Everything from ambient air quality standards to applicable rules (such as NSPS and NESHAP) to major source applicability are covered. This class will be May 8, 2023 and will be online.

To register for Essential Air Permitting, click here.

AERMOD Modeling for Permits

Our next AERMOD Modeling for Permits class will be May 9-10, 2023 and will be online. If you are wanting to get started in modeling, then this class is for you!

To register for AERMOD Modeling for Permits, click here.

Advanced AERMOD

Our next Advanced AERMOD class will be May 11-12, 2023 and will also be online.

Advanced AERMOD covers topics that are near and dear to modelers, such as:

  • NAAQS modeling for 1-hour NO2, 1-hour SO2 and 24-hour PM2.5 (including MaxDCont Viewer)
  • Culpability determination
  • Background concentrations
  • Emission scalars and hourly emission rate files
  • Changes in terrain data processing
  • Changes related to the new Appendix W (Guideline on Air Quality Models)
  • MAXIFILE and ARRAY2 processing
  • AERMOD Wizard and its uses

To register for Advanced AERMOD, click here.

Just as a reminder, if you register more than 30 days before your AERMOD class(es), you will receive a $100 discount on the course fee (per class, per registrant).

On-demand Meteorological Data Processing webinar

We are about to launch a new training option – on-demand webinars. The first of these to be released will be “Meteorological Data Processing for AERMOD”. Look for it at starting this winter.

On-demand AERSCREEN webinar

We will be releasing an on-demand training webinar for AERSCREEN. Watch this space for details!

Don’t forget, if our schedule of classes doesn’t mesh with your schedule, or if you have several people that need to be trained at once, contact us about setting up your own onsite or online class.

2023 Class Dates

The remainder of our 2023 class dates are:

AERMOD Modeling for Permits
August 22-23, 2023
December 12-13, 2023

Advanced AERMOD
August 24-25, 2023
December 14-15, 2023

At this point, all classes will be online.

Quick survey question for you: would you prefer us to teach in-person classes again? If so, what locations would you like us to go to? Previous locations have included Baton Rouge, Denver, Chicago, Raleigh, Houston, San Diego, Atlanta, Burlington, and Austin. Send your responses to


In addition to our newer, faster processors, BeestXpress now runs AERMOD 22112.

If you’ve never used our super-fast BeestXpress before, now is the time. We have released an on-demand webinar that steps you through the process of setting up an account and sending off your first BeestXpress run. You can view the webinar here. New BeestXpress users can complete their first run absolutely FREE. Instructions about receiving the free run are given at the end of the webinar.

BeestXpress users have some great system enhancements to work with:

  • The “Job Details” webpage now displays the pollutant being modeled;
  • The “Job Details” webpage now displays run progress for MAXDCONT calculations;
  • Modeling runs with multiple partitions now include a combined AERMOD input file (*.DTA) in the output .ZIP file;
  • Added an option to the “Submit Job” webpage that affects modeling runs with multiple partitions: the intermediate output files created by each partition can be omitted from the output .ZIP file
  • The “Job Search” webpage now includes the option to search by project number
  • Users have access to up to 99 partitions per AERMOD run

To date, BeestXpress has processed over 500,000 AERMOD runs.

BeestXpress users can log on at to take advantage of our AERMOD “force multiplier”. That AERMOD run that might have taken a day or two to process on your desktop computer can finish in an hour or less on BeestXpress. When time is money, BeestXpress is the best modeling return on investment there is!

Meteorological Data Processing Services

Do you need AERMOD-ready meteorological data? If so, we can help! Whether it’s running national weather service data or onsite monitor met data through the AERMET/AERMINUTE system, Providence has the background, know-how, and experience to have your data processed and ready for you ASAP. If you’d like more information, contact us at or

Consulting Solutions

One thing that we’re very proud of is the depth and range of our modeling experience and expertise. The kinds of air quality models we’ve used include all types, ranging from simple screening tools like SCREEN and AERSCREEN to plume models like ISC and AERMOD to CalPuff. The types of analyses include basic Significant Impact Level, NAAQS, PSD increment consumption, Class I analyses, air toxics and SIP attainment demonstrations. So, we’ve seen it all. To that end, should you or your clients need additional modeling assistance or just a second set of eyes to QA or peer review your modeling (ranging from initial protocol up to final submission), we stand ready to help. Feel free to contact us at (512) 258-8855, (828) 628-0634 or


Calendar separator

April 12-14, 2023
CAPCA Spring Conference
Asheville, NC

May 8, 2023
Essential Air Permitting

May 9-10, 2023
AERMOD Modeling for Permits

May 11-12, 2023
Advanced AERMOD

May 16-17, 2023
TCEQ Environmental Trade Fair
Austin, TX

June 5-8, 2023
AWMA Annual Conference and Exhibition
Orlando, FL