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Ozone Data Exceptional Event Flag Demonstrations

Demonstration documents supporting the proposed exceptional event flags for ozone data.

Exceptional events are unusual or naturally occurring events that affect air quality and are not reasonably controllable or preventable. 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 . The demonstration documents below were developed in support of the TCEQ's proposed exceptional event flags.

Exceptional event regulations and guidance are provided on EPA's Treatment of Air Quality Data Influenced by Exceptional Events website.

Current Exceptional Event Proposals

Houston Ozone Exceptional Events: June 20, September 13, September 21, and October 8, 2022

Public Comment Period: Closed

TCEQ accepted additional written public comments from June 29, 2023 through July 24, 2023. The demonstration was first available for written public comment on May 24, 2023 through June 24, 2023.

All comments received or postmarked by 5:00 p.m. CDT on July 24, 2023 will be submitted to the EPA along with the final demonstration. No public hearing will be held for this action.