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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 Atascosa, Hidalgo, Nueces, Tarrant, and Webb Counties

Public Comment Period: August 5, 2025 – September 5, 2025

TCEQ is posting this demonstration for written public comment on August 5, 2025. For your comment to be submitted to the EPA along with the final demonstration, it must be e-mailed by 5:00 p.m. CDT on September 5, 2025, or it must be postmarked by September 5, 2025.

Submit comments on the demonstration to amda@tceq.texas.gov, with the subject line “2022 PM2.5 Exceptional Events Demonstration - Atascosa, Hidalgo, Nueces, Tarrant, and Webb Counties” or mail the comments to:

TCEQ Air Modeling and Data Analysis Section
MC 164
P.O. Box 13087
Austin, TX 78711-3087.

2023 Atascosa, Hidalgo, Tarrant, and Webb Counties

Public Comment Period: August 5, 2025 – September 5, 2025

TCEQ is posting this demonstration for written public comment on August 5, 2025. For your comment to be submitted to the EPA along with the final demonstration, it must be e-mailed by 5:00 p.m. CDT on September 5, 2025, or it must be postmarked by September 5, 2025.

Submit comments on the demonstration to amda@tceq.texas.gov, with the subject line “2023 PM2.5 Exceptional Events Demonstration - Atascosa, Hidalgo, Tarrant, and Webb Counties” or mail the comments to:

TCEQ Air Modeling and Data Analysis Section
MC 164
P.O. Box 13087
Austin, TX 78711-3087.

2024 Atascosa, Hidalgo, Nueces, Tarrant, and Webb Counties

Public Comment Period: August 5, 2025 – September 5, 2025

TCEQ is posting this demonstration for written public comment on August 5, 2025. For your comment to be submitted to the EPA along with the final demonstration, it must be e-mailed by 5:00 p.m. CDT on September 5, 2025, or it must be postmarked by September 5, 2025.

Submit comments on the demonstration to amda@tceq.texas.gov, with the subject line “2024 PM2.5 Exceptional Events Demonstration - Atascosa, Hidalgo, Nueces, Tarrant, and Webb Counties” or mail the comments to:

TCEQ Air Modeling and Data Analysis Section
MC 164
P.O. Box 13087
Austin, TX 78711-3087.

2022, 2023, and 2024 Harrison, Kleberg and Travis Counties

Public Comment Period: August 5, 2025 – September 5, 2025

TCEQ is posting this demonstration for written public comment on August 5, 2025. For your comment to be submitted to the EPA along with the final demonstration, it must be e-mailed by 5:00 p.m. CDT on September 5, 2025, or it must be postmarked by September 5, 2025.

Submit comments on the demonstration to amda@tceq.texas.gov, with the subject line “2022, 2023, and 2024 PM2.5 Exceptional Events Demonstration - Harrison, Kleberg and Travis Counties” or mail the comments to:

TCEQ Air Modeling and Data Analysis Section
MC 164
P.O. Box 13087
Austin, TX 78711-3087.

2022, 2023, and 2024 Jefferson County

Public Comment Period: August 5, 2025 – September 5, 2025

TCEQ is posting this demonstration for written public comment on August 5, 2025. For your comment to be submitted to the EPA along with the final demonstration, it must be e-mailed by 5:00 p.m. CDT on September 5, 2025, or it must be postmarked by September 5, 2025.

Submit comments on the demonstration to amda@tceq.texas.gov, with the subject line “2022, 2023, and 2024 PM2.5 Exceptional Events Demonstration - Jefferson County” or mail the comments to:

TCEQ Air Modeling and Data Analysis Section
MC 164
P.O. Box 13087
Austin, TX 78711-3087.

2023 and 2024 El Paso County

Public Comment Period: August 5, 2025 – September 5, 2025

TCEQ is posting this demonstration for written public comment on August 5, 2025. For your comment to be submitted to the EPA along with the final demonstration, it must be e-mailed by 5:00 p.m. CDT on September 5, 2025, or it must be postmarked by September 5, 2025.

Submit comments on the demonstration to amda@tceq.texas.gov, with the subject line “2023 and 2024 PM2.5 Exceptional Events Demonstration - El Paso County” or mail the comments to:

TCEQ Air Modeling and Data Analysis Section
MC 164
P.O. Box 13087
Austin, TX 78711-3087.

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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