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An Annual Emissions Report (AER) details a source’s (or facility’s) actual air emissions from the previous calendar year for criteria pollutants and Hazardous Air Pollutants (HAPs). In line with Ben Franklin’s famous quote “In this world nothing can be said to be certain, except death and taxes,” AER reporting joins the list in its required certainty. Similar to filing taxes, AERs are due every year and require a report for the actual emissions emitted, and there are penalties for late or un-submitted reports. Here we use our headquarters’ beloved State of Illinois to illustrate the various elements of AERs.

Illinois Reporting Requirements

The State of Illinois requires any source that maintains, or is required to maintain, an air pollution control permit to file an AER, with the exception of sources registered under the Registration of Smaller Sources (ROSS) program. In the State of Illinois, the Illinois Environmental Protection Agency (IEPA) will send each source the forms necessary to complete their AER on February 1st. In order to properly complete the report, each source should have the following items on hand:

  • The source’s air permit;
  • Records maintained from the previous year in accordance with the source’s air permit;
  • Emission calculation references such as emission factors; and
  • The air permit application if necessary.

The source’s air permit will enable the identification of each emission unit that is permitted. Most air permits will also provide guidance, if not specifics, on the “how-to” for completing their emissions calculations. If the IEPA does not send the necessary forms, it is still the source owner’s responsibility to procure the forms and file a timely report. Contact information is provided under the IEPA Annual Emission Reports Questions or Problems.

For AER Reporting in the State of Illinois, two types of reports are possible for a qualifying AER source, a short and a long option. In order to qualify for a long report a source must qualify as one of the following:

  • Clean Air Act Permit Program (CAAPP) (Title V) sources
  • Sources with total allowable emissions greater than 25 tons per year
  • Sources located in an ozone non-attainment area with potential nitrogen oxides (NOx) or volatile organic material (VOM) emissions greater than 25 tons per year

If none of the above requirements are met, the source will qualify for the short report category, which most commonly are sources that maintain a lifetime operating permit.

Something to keep in mind while calculating your source’s actual annual emissions and completing the AER is that it is also a good time to check if your source is eligible for the ROSS program. The IEPA created the ROSS Program in accordance with Public Act 097-0095. The ROSS Program is structured to simplify regulatory requirements including AERs, for sources with small emissions. To determine if a source is eligible under the ROSS Program, their emissions must be less than 5.0 tons per year of combined pollutants (particulate matter, carbon monoxide, nitrogen oxides, sulfur dioxide, and volatile organic material) and less than 0.50 tons per year of combined HAPs. To determine verification of a source in the ROSS Program, the IEPA provides guidelines and helpful tools to determine a source’s eligibility.

All AERs in the State of Illinois are due by May 1st and must reflect the previous year’s emissions.

AERs Vary State by State

Requirements vary from state to state. To illustrate how each state can vary, we’ve created a simple example using a few of the states where we have offices.

State Who is required to submit? When are Emission Reports due from the previous year? Where to submit?
Illinois Any facility that has or is required to have a State of Illinois air pollution control permit, is required to file an AER. May 1st

Submit to the Illinois EPA Bureau of Air, Air Quality Planning Section (#39)

1021 North Grand Avenue East

P.O. Box 19276

Springfield, IL 62794-9276

Minnesota Any facilities required to obtain an air pollution control permit must submit an annual emission inventory April 1st Electronic submission available through the e-Services electronic reporting website
Pennsylvania All Title V, synthetic minor, permit cap compliance certification, oil and gas facilities are required to submit an annual emissions inventory. However, the state of Pennsylvania may reach out to other facilities with a non-Title V air permit and request an emissions inventory per 25 Pa. Code Chapter 135. March 1st Electronic submission required through the AER Online or AES XML Applications
Tennessee Any facility whose potential emissions equal or exceed thresholds for any of the criteria pollutants is required to submit emissions data. June 1st Electronic submission required through the State/Local Emissions Inventory System (SLEIS)


As you can see, each state can have slight differences in who is required to report and when. It’s important to make sure you know when AERs are due in your state, if you need to submit one as part of your air permitting status, and what needs to be included. While AER reporting and qualification can seem daunting, many States provide a variety of helpful tools and guidance to assist any source with successfully filing their required reporting documents if you choose to go it alone – or, a consultant with expertise in your area can help make sure the process runs smoothly.



Illinois EPA AER FAQs

EPA List of Hazardous Air Pollutants

Minnesota Air Emissions Reporting

Minnesota Air Emissions FAQs

Pennsylvania Instructions for Submitting Air Quality Emission Inventory Reports

Registration of ROSS Programs

ROSS Program Fact Sheet

Tennessee Emissions Inventory Reporting Requirements

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