Air Dispersion Modeling | Valley Air District

Air dispersion modeling uses source input parameters, meteorological data, terrain, and other default modeling parameters to estimate the downwind dispersion of a pollutant emitted by a source. Dispersion modeling is an important tool used by air districts and other agencies to determine compliance with California and National Ambient Air Quality Standards (CAAQS/NAAQS) and to determine the potential localized health impacts from a project under the District’s permitting process, the AB 2588 Hots Spots program (AB 2588), and California Environmental Quality Act (CEQA). To assist local businesses and project proponents, please reference the helpful modeling and risk assessment resources linked below.

Resources

District Guidance
District Air Dispersion Modeling Guidance

EPA
AERMOD Modeling System

CARB/OEHHA
Hot Spots Analysis and Reporting Program (HARP)
OEHHA’s Health Risk Assessment Guidance
California and National Ambient Air Quality Standards

California Air Pollution Control Officers Association (CAPCOA)
CAPCOA Facility Prioritization Guidelines

District Tools
Flares
Volume source modeling parameters
Prioritization Screening AB2588 Calculator
Prioritization Screening RMR Calculator

For assistance or if you have any questions, please feel free to contact the District at HRAmodeler@valleyair.org.