Planning and Modeling Program - Emissions Inventory
The Planning and Modeling Program collects and prepares emissions data annually for the National Emissions Inventory (NEI) of US EPA and for NDEP planning and billing purposes.
EPA's Emission Inventory and Analysis Group (EPA/OAR/OAQPS/AQAD/EIAG) prepares a national database of air emissions information with input from numerous State and local air agencies, from tribes, and from industry. This database contains information on stationary and mobile sources that emit criteria air pollutants and their precursors, as well as hazardous air pollutants (HAPs). The database includes estimates of annual emissions, by source, of air pollutants in each area of the country, on an annual basis.
Data from the NEI are used for air dispersion modeling, regional strategy development, regulation setting, air toxics risk assessment, and tracking trends in emissions over time. For emission inventories prior to 1999, criteria pollutant emission estimates were maintained in the National Emission Trends (NET) database and HAP emission estimates were maintained in the National Toxics Inventory (NTI) database. Beginning with 1999, criteria and HAP emissions data were prepared in a more integrated fashion in the National Emission Inventory (NEI), which takes the place of the NET and the NTI.