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Air Emissions Inventories

2008 National Emissions Inventory (NEI) Data


The 2008 NEI Technical Support Document is a draft and using an improved format from past documents.  Although in draft form, this version provides all of the documentation available in past 2008 NEI releases as well as additional analysis about the sources of data used the NEI.  Placeholder sections are included so that major section numbers will not change in future versions.  This draft document will be replaced with updated versions as they become available.  Requests for updated sections can be made to the to the Info CHIEF Help Desk at

  • 2008 NEI Technical Support Document, Draft (updated 9/2013)
  • Supporting Data and Summaries (updated 9/2013) - See Section 8 of the Technical Support Document for a list of supporting files and their contents. The contents are accurate and not draft, though more supporting data may be added later. 
  • References (ZIP) (36.6MB) (updated 9/2013) - Throughout the documentation, references are made to EPA documents developed as part of the 2008 NEI effort. These are available in this zipped file. See also Section 8 of the Technical Support Document. 

Related Documents

The data posted at this site will include only the latest version of the 2008NEI.  This webpage should not be used as a reference for past versions of the NEI and users wanting a record of data used in their analysis should archive and document those inventories to meet their own archival needs.  Users should not assume that the data posted on this site will stay the same as the data they use at a given point time.

The full detail data files for the Point, Onroad, Nonroad and Nonpoint data categories can be downloaded from the list below. Please note these files are larger than previous inventories and can be linked in Access if importing fails. These SCC data files do not include “events” data -wildfires and prescribed burning emissions. The events data can be found at the “Prescribed/Wildfires by Pollutant” link below under “Other Emissions Summaries”. To obtain a complete inventory total, please include these data in addition to the 4 SCC data files provided here.

Additional Summary Data

  • Tribal Lands Emissions Summaries

    • Sector (XLS) (647KB) (include both criteria and hazardous air pollutants)
    • Tier 1  (XLS) (87KB) (Includes criteria pollutants only)
  • Other Emissions Summaries

    • Facility-level by Pollutant: (ZIP) (110.0 MB)  Facility-level summary 
    • All Sector: (ZIP)  (33.7 MB) National - county aggregated - sector file
    • Biogenics: (ZIP) (14.3 MB) Various levels of aggregation down to monthly county emissions
    • Tier Summaries: National/State/County summaries for Tier 1, Tier 2 and Tier 3
    • 2008 Version 3 Pb facility-process: (ZIP) (CSV, 3.11MB) Point source facility-process summary for lead (Pb) 
    • 2008 Version 3 Hg: (ZIP) (34.7 MB) Point source facility-process, nonpoint, onroad, nonroad and national summary for mercury (Hg)

Files that can be used for air quality modeling can be found at the Air Emissions Modeling.

Sector Summaries - Criteria and Hazardous Air Pollutants by 60 EIS emission sectors

*A complete sector file is provided below under "Additional Summary Data". To use the multiple selection boxes hold CTRL and click on options you would like to include in your query. To select multiples in order, click your first option then hold SHIFT + click the last selection to highlight everything in between. To unselect options use the same method as with selecting. Please allow time for large queries to process (i.e. county aggregated for all pollutants, all regions, selected sector).

National / State / County or Tribe Geographic Aggregation
Pollutant Sector
  *Query results will be displayed below.  CAP emissions are in short tons.

Tier 1 Summaries - Criteria Air Pollutants only by 14 major tiers

National / State / County or Tribe Geographic Aggregation
Pollutant Tier 1 Category
  *Query results will be displayed below.  CAP emissions are in short tons.

The facility query will provide a map of facilities for a selected state along with tabular data for the selected pollutant(s).  Please note that the map will only display if there are less than 25 pollutants selected.  If more than 25 pollutants are selected then only the tabular data will be displayed.

State Pollutant
  *CAP emissions are in short tons.