Dispersion Modeling

Atmospheric dispersion models are computer programs that use mathematical algorithms to simulate how pollutants in the ambient atmosphere disperse and, in some cases, how they react in the atmosphere. Dispersion models take the facility’s emissions (e.g., in terms of lbs/hr) along with local topography and meteorological data and establish a concentration footprint in the vicinity of the facility. 


The concentrations calculated with dispersion models can be compared with air quality standards.  The results of the dispersion models are also used in risk assessments models to determine health risks. 

EPS maintains a full suite of dispersion models such as: 


  • CalPUFF 

  • SACTI 




These models have been approved by the federal and state regulatory agencies thereby providing technically and legally defensible model results. Contact EPS staff to learn how dispersion models can be effectively used for your application.