DEEP: Air Quality Modeling

Air Quality Modeling

Background on Air Quality Modeling:

The Clean Air Act as amended in 1977 mandated that air quality modeling be used as a tool to assess compliance with certain provisions of the Act. These provisions include attainment and maintenance of national Ambient Air Quality Standards and prevention of significant deterioration of air quality.

What is Air Quality Modeling?

Air quality models use mathematical techniques to simulate the physical and chemical processes that affect air pollutants as they scatter throughout the atmosphere. Based on inputs of meteorological data and source information, these models are designed to characterize both primary and secondary pollutants that are either emitted into the atmosphere or are formed as a result of complex chemical reactions within the atmosphere. Monitoring of air quality, on the other hand, is normally only performed at a fixed location for a limited duration. Modeling, therefore, complements monitoring by filling in information gaps in space and time.

What is the purpose of Air Quality Modeling?

Air Quality Modeling is used to assess the impact of air pollution from stationary sources.  The Connecticut Regulations for the Abatement of Air Pollution require stationary sources of air pollution to be registered through the DEP, so Modeling is also the way to obtain a Permit to construct new sources or to modify existing sources.  Air Quality Models can help in determining the needed controls to bring a source to attainment standards as well.

Guidance Documents and Data Hyperlinks:

DEP Modeling Guidance (Revised 12/09)

Interim PM2.5 NSR Modeling Policy and Procedures (02/11/09)

Background Air Quality for Modeling

Meteorological Data

EPA Air Quality Modeling Information 

Content Last Updated on December 29, 2009