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Exceptional Event Demonstrations for Particulate Matter

Demonstrations supporting the proposed exceptional events for particulate matter 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.

Draft Exceptional Event Proposals

2022 El Paso and Laredo PM10 Demonstration for Two days

Public Comment Period: open

This demonstration was posted for written public comment on Apr. 10, 2025. We will submit all comments received or postmarked by 5:00 p.m. CDT on May 9, 2025, to the EPA along with the final demonstration. No public hearing will be held for this action.

Finalized Exceptional Event Demonstrations (Submitted to EPA)

El Paso, Nueces, and Harris County PM10 Demonstration for Three Days in 2021

El Paso Demonstrations

December 23, 2020 PM10 Exceptional Event

2017-2018 PM10 Exceptional Events

2010-2012 PM2.5 and PM10 Exceptional Events

Houston Clinton Monitor Demonstrations (English Only)

2012 Exceptional Events

2011 Exceptional Events

2010 Exceptional Events

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