An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Air Emissions Inventories

2020 National Emissions Inventory (NEI) Documentation

The NEI database includes air emissions sources of both criteria of both criteria and hazardous air pollutants. Data are available for many facilities and as county totals. The 2020 NEI is the next inventory on the three-year cycle and the EPA will create it using data provided by State, Local and Tribal air agencies. The Emissions Inventory System (EIS) helps the EPA to build the NEI.

2020 NEI Development Documentation

2020 NEI Plan