Adobe Acrobat Reader is required to view and print PDF files. Adobe Acrobat is required to edit online forms and save them to your computer.

Last Updated: Thursday, January 5, 2012 12:14 PM

EMFAC Software

Emission factors that represent the vehicle fleet, speeds, and environmental conditions associated with a project are needed to perform project-level air quality modeling.The EMFAC model issued by the California Air Resources Board is used for this process in California. For more details regarding project-level "hot spot"modeling, please refer to the CO Protocol, Appendix B and the U.S. EPA's latest guidance for particulate matter hot spot analysis.

EMFAC 2011 was released by ARB on September 30, 2011. It has not yet been officially made available for conformity analysis purposes by U.S. EPA. Until EPA announces availability in the Federal Register, CONFORMITY ANALYSIS will continue to use EMFAC 2007. New air quality analysis for other purposes (not related to conformity analysis) may and should start using the new version immediately.

EMFAC 2007 was required for new project-level conformity studies starting after July 31, 2007 (6 months after ARB final release; see FHWA letter, second page). The grace period for completing project studies using EMFAC 2002 has expired. Project-level air quality studies for conformity purposes use EMFAC 2007: U.S.EPAmade EMFAC 2007 available for conformity use through a notice of availability in the Federal Register on January 18, 2008 (PDF or HTML file at EPA) .

All versions of the EMFAC software since 2000 are available from the ARB web http://www.arb.ca.gov/msei/msei.htm.

The EMFAC model and all supporting data are provided and supported by the California Air Resources Board .

CT-EMFAC

Caltrans and UC Davis have interpreted the EMFAC 2007 model to provide a simplified user interface for project-level emission analysis, including emission factors and emission burden of criteria pollutants typically analyzed and Mobile Source Air Toxics (based on ARB's speciation factors for Total Organic Gases - TOG). For more information and to download the software package, see the CT-EMFAC page.

CT-EMFAC is based on EMFAC 2007, and in its present form should not be used for new environmental studies started after October 1, 2011. However, it may still be used to assist with conformity-related studies until U.S. EPA makes EMFAC 2011 available for conformity analysis purposes and any grace periods set by EPA and FHWA expire. The web-interface version of EMFAC 2011 provides many of the features available in CT-EMFAC.

 

Return to Air Quality Home Page