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Air Emissions Factors and Quantification

Procedures for the Development of Emissions Factors from Stationary Sources

Recommended Procedures for Development of Emissions Factors and Use of the WebFIRE Emissions Factor Database - Draft Final (PDF) (102 pp, 2.8 M, About PDF) August 2013

This document supersedes the draft final document posted in July 2013; however, the August version of this document is the same as the July version with the following exceptions:

  • the official EPA title, cover, and back cover pages were added, and
  • revisions were made to Appendix B (Procedures for Handling Test Data That are Below the Method Detection Limits) to clarify the procedures that are followed in cases where the minimum detection limit (MDL) for data that are below the MDL (BDL) is not contained in the Electronic Reporting Tool (ERT).

This guidance document describes the procedures, data evaluation criteria, and associated tools and data management systems that the U.S. Environmental Protection Agency (EPA) recommends for developing air pollutant emissions factors for stationary emissions units or processes. This will supersede the previous EPA guidance document for emissions factor development (Procedures for Preparing Emission Factor Documents (EPA-454/R-95-015, November 1997))

The report presents an introduction to emissions factors and provides the historical background for how and why the EPA has developed recommended emissions factors for stationary emissions units or processes. It also describes the approach and new procedures that EPA will follow when developing new or revising existing recommended emissions factors.

Included is an overview of EPA’s interactive emissions factors database, WebFIRE, and a discussion of the role the Electronic Reporting Tool (ERT) plays in submitting emissions test data to EPA. Finally, this document provides an overview of the data review and public participation process that the EPA should follow when developing new or revised recommended emissions factors.