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Air Emissions Inventories

2011 National Emissions Inventory (NEI) Data


Documentation for the 2011 NEI is ongoing at this time. Updates will be posted as available.  Requests for additional information can be made to the Info CHIEF Help Desk at

  • Nonpoint Emissions Tool and Methods

    • Nonpoint Categories (xlsx)(1 pg, 18 K) that EPA is developing emission estimates for or planning to pull forward the 2008 estimates for use in 2011, if not provided by Agencies. (Updated September 2012)
    • Data and documentation:  MS Excel spreadsheets with emission factors, activities and county level allocation factors, and MS Word documents that describe the methodology used to estimate emissions
    • Oil & Gas Emission Estimation Tool: (ZIP 6.5 MB) Includes the Access database tool, Supporting Materials, Documentation and Instructions for version 2. (Updated November 2014)
  • Onroad Mobile Resources

    • Example run specification file:  Sample county run specification file for 2011 NEI.
    • Generic CDB Creator (ZIP)(13 pp, 2 MB) XML template for creating CDBs for submission to the NEI
    • QA Tools:  Tools to QA CDBs and to create the required QA Reports for EIS CDB submission
    • CDB Sampler Header (xml)(1 pg, 2 K) file that can be edited for EIS submittal as an alternative to creating it via Bridge Tool Staging Tables
    • National County Checklist (xlsx)(1 pg, 101 K) : checklist that indicates which tables the agency has revised from EPA's defaults for each county's CDB

The data posted at this site will include only the latest version of the 2011 NEI.  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) (189 KB) (Includes both criteria and hazardous pollutants)
    • Tier 1 (xls) (64 KB) (Includes criteria pollutants only)
  • Other Emissions Summaries

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 provides a map of facilities for a selected state along with tabular data for the selected pollutant(s).  Please note that the map only displays 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.