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Dispersion Models

A dispersion model is a mathematical formulation which:

With the dispersion model, temporal and spatial estimates of pollutants from transportation and other sources, along with estimates of background pollution and weather conditions, are combined. When this analysis is completed, comparisons of estimated pollution concentrations with the National Ambient Air Quality Standards (NAAQS) are made to determine whether control action is needed to reduce emissions.

Preferred dispersion models are published in Appendix W (PDF) of 40 CFR Part 51.


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Updated: 1/30/2014
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