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Dispersion Modeling


PSD Baseline Dates

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.


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)