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Chemical Mass Balance (CMB) Model

The Chemical Mass Balance (CMB) Model EPA-CMBv8.2 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. Guidance in their use may be found in Section 5.2.2 of the " Guideline on Air Quality Models".

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
Source Code

Model Documentation
Users Manual
CMB Protocol
Peer Review
Response to Peer Review
Model Change Bulletin
Presentation with Demo (A&WMA's 98th Annual Conference, 23 June 2005; Minneapolis, MN)

Evaluation Data Sets
Test Data Set  
Other Data Sets Formated for CMB Input
   Portland Aerosol Characterization Study (PACS):
     Data Set
   San Joaquin Valley Fine (SJVF):
     Data Set
   Coastal Oxidant Assessment for Southeast Texas (COAST):
     Data Set
   North American Research Strategy for Tropospheric Ozone (NARSTO):
     NARSTO Documentation
     Data Set
   Northern Front Range Air Quality Study (NFRAQS):
     NFRAQS Executive Summary
     Data Set

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