June 4, 2020
Air Dispersion Modeling for Chemical Compounds in Support of Air Permit Applications in Texas
Albert Kennedy, Sr. Project Manager, BGE, Inc.
When seeking a New Source Review air permit for a chemical project in Texas, timely permit issuance often greatly depends on being able to demonstrate acceptable modeling impacts for each non-criteria pollutant constituent in a timely manner. The TCEQ has established Effects Screening Levels (ESLs) for chemical compounds that define acceptable impact thresholds and the Modeling and Effects Review Applicability (MERA) guidance that defines the process for demonstrating acceptable impacts. While some model-predicted exceedances of ESL thresholds are allowed by TCEQâ€™s Toxicology Division, the magnitude and extent of predicted exceedances must be limited. An overview of the TCEQâ€™s review process and the model-predicted impacts typically deemed acceptable will be presented. In addition, common techniques for demonstrating acceptable impacts as quickly and efficiently as possible and common refinement techniques for problematic modeling results will also be discussed.