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EPA Releases Additional Resource on Prescribed Fires to Support Air Agencies

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EPA Press Office (

WASHINGTON (August 14, 2019) — The U.S. Environmental Protection Agency (EPA) has issued new guidance that will help State, Local and Tribal air agencies and key federal partners show that certain air quality impacts from prescribed fire on wildlands should be excluded from some regulatory uses. The guidance, Exceptional Events Guidance: Prescribed Fire on Wildland that May Influence Ozone and Particulate Matter Concentrations (“the Prescribed Fire Guidance”) will help streamline the demonstration development and review process.

“EPA recognizes and supports the use of prescribed fires as an important tool to promote proper forest management and reduce the risk of catastrophic wildfires,” said EPA Administrator Andrew Wheeler. “This guidance is consistent with President Trump’s executive order and promotes active forest management by helping air agencies and our federal partners show that air quality impacts from prescribed fire on wildlands should be excluded from some regulatory uses.”

Consistent with President Donald Trump’s December 2018 Executive Order on Promoting Active Management of America’s Forests, Rangelands, and other Federal Lands to Improve Conditions and Reduce Wildfire Risk, EPA supports actively managing these lands through partnerships with states, tribes, communities, non-profit organizations, and the private sector. This active forest management includes the use of prescribed fires, and the Prescribed Fire Guidance supports active forest management within the framework of the 2016 Exceptional Events Rule.

In response to stakeholder feedback, the Prescribed Fire Guidance organizes and clarifies how to meet key provisions of the 2016 Exceptional Events Rule, including how to demonstrate that a prescribed fire caused the event-related exceedance(s) or violation(s), was not reasonably controllable or preventable, and is unlikely to recur at a particular location. The guidance also promotes collaboration between state, local, and tribal air agencies and land managers and describes what kinds of information may be helpful to include in a Smoke Management Program or Basic Smoke Management Practices.

Exceptional events are unusual or naturally occurring events (e.g., wildfires, high-wind dust events) that can affect air quality and whose emissions are not reasonably controllable by air agencies. EPA finalized the 2016 Exceptional Events Rule to improve criteria and procedures for determining if air quality monitoring data has been influenced by exceptional events. The Prescribed Fire Guidance is part of EPA’s broader effort to facilitate the 2016 Exceptional Events Rule implementation process. In support of these efforts, EPA has also released the following guidance documents and implementation resources:

  • Final Guidance on the Preparation of Exceptional Events Demonstrations for Wildfire Events that May Influence Ozone Concentrations
  • Guidance on the Preparation of Demonstrations in Support of Requests to Exclude Ambient Air Quality Data Influenced by High Wind Dust Events Under the 2016 Exceptional Events Rule
  • Guidance on the Preparation of Exceptional Events Demonstrations for Stratospheric Ozone Intrusions
  • 2016 Revisions to the Exceptional Events Rule: Update to Frequently Asked Questions
  • Additional Methods, Determinations, and Analyses to Modify Air Quality Data Beyond Exceptional Events
  • 2007-to-2016 Exceptional Events Rule Crosswalk
  • Best Practices for Preparation of Multi-Agency Exceptional Events Demonstrations
  • Mitigation Plan Checklist

These and other resources can be found on EPA’s exceptional events website at


Exceptional events are unusual or naturally occurring events that can affect air quality but are not reasonably controllable, and for which tribal, state or local air agencies may submit a demonstration to request exclusion of event-related air quality data from certain regulatory determinations to attain and maintain the National Ambient Air Quality Standards (NAAQS). Examples of the kinds of events that may qualify as exceptional events include high wind dust events, wildfires, prescribed fires, stratospheric ozone intrusions, and volcanic and seismic activities.

Section 319(b) of the Clean Air Act (CAA) provides the statutory basis for excluding air quality data that have been influenced by exceptional events from certain types of regulatory determinations. Pursuant to Section 319(b), EPA promulgated the first Exceptional Events Rule on March 22, 2007. The rule set forth definitions and requirements for exceptional events, and requirements for air agencies to take appropriate and reasonable actions to protect public health from exceedances or violations of the NAAQS. As a result of our experiences related to implementing the 2007 Exceptional Events Rule, EPA developed and released Interim Exceptional Events Implementation Guidance documents in May 2013. The Interim Guidance also announced EPA’s intent to pursue revisions to the 2007 Exceptional Events Rule, and EPA initiated stakeholder consultations to inform the process.

EPA revised the Exceptional Events Rule in 2016 with the aim of streamlining the demonstration process for air agencies while upholding the associated CAA principles for protecting public health. As part of this process EPA has eliminated the “backlog” of exceptional events demonstrations awaiting review.  EPA continues to engage with stakeholders to seek feedback and ensure that the issues they raise about the Exceptional Events Rule are being addressed, and their experience developing exceptional event demonstrations is streamlined. EPA is also continuing to develop resources regarding the Exceptional Events Rule revisions and implementation process.