Download PDF

The Texas Commission on Environmental Quality (“TCEQ”) has updated:

Modeling and Effects Review Applicability (“MERA”) Guidance Document (“Guidance”)

TCEQ states that a previous draft of the Guidance was published September 15, 2017, and they received comments on the draft.

The updated document includes changes made in response to the comments received. Further, it is stated to contain limited technical changes along with opportunities for streamlining the health impacts review process (while continuing to ensure the protection of human health and welfare).

Air quality dispersion modeling is often used in conjunction with monitoring and is used to estimate the probably concentration of a given pollutant at a certain geographical point. The models use emission data along with meteorological information to produce such predictions.  Additional information components utilized are the chemistry of air emissions and topographical features in the relevant area. Changes to model components (i.e., meteorological data, etc.) will affect the resulting estimated air pollutant concentrations. The models are sometimes adjusted (i.e., “calibrated”) as better information becomes available to improve their accuracy. Complexity of the models can vary.

A copy of the Guidance can be downloaded here.