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United States Department of TransportationUnited States Department of Transportation

Emissions and Dispersion Modeling System (EDMS)

The Emissions and Dispersion Modeling System (EDMS) has been replaced by the Aviation Environmental Design Tool (AEDT) as of May 2015.

The Emissions and Dispersion Modeling System (EDMS) was developed in the mid-1980s as a complex source microcomputer model designed to assess the air quality impacts of proposed airport development projects.

What was EDMS designed to do?

EDMS was designed to assess the air quality impacts of airport emission sources, particularly aviation sources, which consist of:

  • Aircraft
  • Auxiliary power units
  • Ground support equipment
  • Ground access vehicles
  • Stationary sources

EDMS was one of the few air quality assessment tools specifically engineered for the aviation community. It included:

  • Emissions and dispersion calculations
  • The latest aircraft engine emission factors from the International Civil Aviation Organization (ICAO) Engine Exhaust Emissions Data Bank
  • Vehicle emission factors from the latest version of the Environmental Protection Agency's (EPA) MOBILE6 model
  • EPA-validated dispersion algorithms
  • Emissions data for criteria pollutants and speciated organic gas emissions OGs (45 HAPs and 349 non-toxic compounds).

FAA required model

As of May 29, 2015, FAA revised its policy on air quality modeling procedures to identify AEDT as the required model to perform air quality analyses for aviation sources instead of the preferred model. This revised policy ensures the consistency and quality of aviation analyses performed for FAA. The FAA continues to enhance the model under the guidance of its government/industry advisory board to more effectively determine emission levels and concentrations generated by typical airport emission sources.

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