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Support Center for Regulatory Atmospheric Modeling (SCRAM)

Chemical Mass Balance (CMB) Model

The Chemical Mass Balance (CMB) Model EPA-CMB v8.2 is one of several receptor models that has been applied to air quality problems over the last two decades. Based on an effective-variance least squares method (EVLS), EPA has supported CMB as a regulatory planning tool through its approval of numerous State Implementation Plans (SIPs) which have a source apportionment component. CMB requires speciated profiles of potentially contributing sources and the corresponding ambient data from analyzed samples collected at a single receptor site. CMB is ideal for localized nonattainment problems and has proven to be a useful tool in applications where steady-state Gaussian plume models are inappropriate, as well as for confirming or adjusting emissions inventories.

Chemical Mass Balance Model EPA-CMB8.2
Windows-based EPA-CMB8.2 represents the latest advancement in the CMB series and replaces CMB7. EPA-CMB8.2 has been subjected to peer review and is available for regulatory applications.

Model Code
README (PDF)(1 pg, 22 K, 06-29-2005)
README - Supplemental (PDF)(1 pg, 78 K, 07-28-2016)
Executable (ZIP)(1 MB, 06-29-2005)
Source Code (ZIP)(5 MB, 06-29-2005)

Model Documentation
Users Manual (PDF)(123 pp, 895 K, 12-01-2004, 452-R-04-011)
CMB Protocol (PDF)(173 pp, 784 K, 12-01-2004, 451-R-04-001)
Peer Review (PDF)(52 pp, 293 K, 01-28-2005)
Response to Peer Review (PDF)(6 pp, 65 K, 06-01-2005)
Model Change Bulletin (TXT)(2 K, 06-29-2005)
Presentation with Demo (PPT)(45 pp, 2 MB, 06-23-2005) (A&WMA's 98th Annual Conference, 23 June 2005; Minneapolis, MN)

Evaluation Data Sets
Other Data Sets Formatted for CMB Input: