Exceptional Event Demonstrations for Ozone
Demonstration documents supporting the proposed exceptional events for ozone data.
About Exceptional Events
Definition
Exceptional events are unusual or naturally occurring events that affect air quality and are not reasonably controllable or preventable. Wildfires, prescribed fires, high winds blowing dust, dust from the Sahara Desert, fireworks to celebrate days such as July 4th, etc., can be considered exceptional events.
How They Affect Monitoring Data
States can request that the United States Environmental Protection Agency (EPA) exclude air quality monitoring data affected by an exceptional event from determining if an area met an air quality health standard . This page provides access to exceptional event demonstration documents developed by TCEQ.
EPA Regulations and Guidance
Exceptional event regulations and guidance are provided on EPA's Treatment of Air Quality Data Influenced by Exceptional Events website.
Finalized Exceptional Event Demonstrations (Submitted to EPA)
Houston Ozone Exceptional Events: June 20, September 13, September 21, and October 8, 2022
- Demonstration Summary (English)
- Demonstration Summary (Spanish)
- Exceptional Event Demonstration Document for the Houston Bayland Park (CAMS 53) and Houston Harvard Street (CAMS 417) Monitoring Sites (25 MB)
Dallas-Fort Worth Exceptional Events: August 16, 17, and 21, 2020
- Exceptional Event Demonstration Document for the Grapevine Fairway (CAMS 70) Monitoring Site (13 MB)
- EPA response to 2020 DFW exceptional event demonstration
El Paso Ozone Exceptional Event: June 21, 2015
- Exceptional Event Demonstration Document for the University of Texas El Paso (CAMS 12) Monitoring Site
- Addendum 1 – Memorandum: CAMx Modeling of June 21, 2015
- Addendum 2 – Wildfire Impacts on Ozone at the El Paso UTEP CAMS 12 Monitor on June 21, 2015: PowerPoint with Animations
- Addendum 3 – Additional Information
- Addendum 4 – Update - Trajectories and CAMx Modeling
- EPA Concurrence Letter to TCEQ
Houston Exceptional Event: August 26, 2011
- Exceptional Event Demonstration Document for the Houston East (CAMS 1) Monitoring Site
- EPA response to 2011 HGB exceptional event demonstration
- TCEQ response letter to EPA