Modeling

Dispersion Modeling

The Air Quality Bureau modeling staff conduct local scale dispersion modeling, which is generally associated with the construction permit application process. It is used to predict the air quality impact of new or modified emission sources. The modeling staff conducts or reviews modeling for minor and major sources. Other uses of dispersion modeling include: analysis of monitored violations of the National Ambient Air Quality Standards (NAAQS), assistance in planning, and the development of rules.

• General Guidance
• PSD Modeling Guidance
• Source Characterization Guidance/Tools

• Dispersion Modeling Guidelines
• Air Dispersion Modeling Checklist |
• Non-PSD Dispersion Modeling Determination - Form MD |
• Availability of Air Resources
• DNR Suggested Methodology for Modeling Restricted Hours of Operation
• EPA memo: Ambient Air
• EPA memo: Guidance for 1-hour NO2 NAAQS
• GEP Technical Support Document
• Rounding of Modeled Concentrations for Comparison with the NAAQS
• Understanding Air Quality Evaluation Tools

• PSD Modeling Guidelines
• Modeling Protocol Template |
• Soils and Vegetation Analysis Tool
• VISCREEN Tool
• Air Quality Criteria for Oxides of Nitrogen - Vegetation Impacts
• "A Screening Procedure for the Impacts of Air Pollution Sources on Plants, Soils, and Animals" (EPA 450/2-81-078, December 1980)

 

PSD Baseline Dates

Pollutant	Major Source Baseline Date	Minor Source Baseline Date
NO2	February 8, 1988	March 14, 1988
SO2	January 6, 1975	September 6, 1978
PM10	January 6, 1975	Varies by location Baseline Area Map (Google Earth file)
PM2.5	October 20, 2010

 The source characterization guidance was initially developed to assure consistency in the methodologies used by DNR staff to characterize emission sources in an air dispersion modeling analysis. In general the guidance addresses those emission sources modeled as pseudo- or non-point sources; however the guidance also addresses stacks with capped or horizontal type discharge. This guidance is not intended to preclude other methodologies for characterizing emission sources.

• Bin Vents
• Concrete Batch Plants
• Dump Pits
• Flare Guidance
• Flare Tool
• Grain Dryers
• Haul Roads
• Stacks and Vents
• Storage Piles
• Storage Tanks
• Truck or Rail Loadouts
• Volume Source Tool
• Volume Source Characterization

Data

• Meteorological Data (Pre-processed)
• Elevation Data (Pre-processed)
• Background Data

Useful Offsite Links

• SCRAM (EPA's Support Center for Regulatory Air Models)
• CHIEF (EPA's Clearinghouse for Inventories & Emission Factors)
• USGS (United States Geological Survey)
• NCDC (National Climatic Data Center)