AERMOD UPDATESBeth EchelsKeith Zimmermann, P.E.

The goal today is to discuss the progress and status of TCEQs implementation of AERMOD and how to streamline the review of your modeling.

RECENT NEWSRECENT CHANGES TO: AERMET AERMAP AERMOD

OTHER NEWS

AERMOD FAQsWhat are the most frequently asked questions that we hear from you?

AERMET QUESTIONChoice of Preprocessed Meteorological DataShould I use:Low Roughness?Medium Roughness?High Roughness?

Example of Low Roughness

Relatively flat area with homogeneous characteristics within the modeling domain.

Low grassFew treesVery low vegetationBarren land, mostly desert

Example of Medium Roughness

Typical rural or suburban area with a mixture of vegetation (low and high) and scattering of trees, and buildings within the modeling domain.Tall crops and grassesScattering of treesSuburban areaMixture of low buildings and open areas

Example of High Roughness

Typical urban and/or industrial area. Many buildings and structures or forested area.Buildings and structures closely packedForested areasHighly congested industrial area

AERMAP QUESTIONUse of Terrain DataShould I:use DEMS?zero out the receptors, etc.?use the Non-regulatory default option?

AERMOD QUESTIONMay I use the Urban Option?Requires:Roughness parameter valuePopulation valueIs it appropriate?

We must all rely on experience and judgment in the proper use of dispersion models to demonstrate a reasonable worst case.

How can I streamline my modeling review?

RecommendationsUse the model input TemplatesAllows electronic submittal of data in a form conducive to automated checking.

RecommendationsDocument your workExplain what you did and why you did it.Use current guidance for your report format.Submit all spreadsheets with calculations (Flare calculations, scaling calculations, etc.).

RecommendationsProvide electronic copy of modeling input, output, and plot files.Input, output, downwash, and plot filesElectronic plot plan

Questions?