Exceptional Events Rule Information Page

The Exceptional Events Rule (EER) provides a way for states to flag air quality data for possible exclusion when NAAQS compliance is determined, provided the EPA concurs with the supporting documentation, and the event contributing to the data meets certain criteria. Exceptional Events are those events that impact air quality but are not reasonably controllable, and not likely to reoccur. Wildland fires are among the exceptional events states flag under this rule.

In September 2016 the EPA finalized the revisions to the Exceptional Events Rule. EPA's webpages and documents outlining the new rule, guidance, and other resources are listed below:

Treatment of Data Influenced by Exceptional Events - EPA information page for the Exceptional Events Rule and its status, links to:

  • EER Guidance
  • Webinars
  • EER examples
  • Publicly available support information and tools

Exceptional Events Rule and Guidance - EPA's Exceptional Events Rule guidance page which includes:

  • The Final Rule
  • EER guidance document
  • Responses to public comments
  • Fact sheets
  • Federal register notice
  • Prior drafts of the rule and guidance