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Clarification Memos

Provides access to memoranda issued by EPA as general clarifications for issues related to Appendix W and technical aspects of dispersion models, when necessary.


Clarification on Regulatory Status of Proprietary Versions of AERMOD (PDF) (12-11-2007)

Clarification on Regulatory Status of Calpuff for Nearfield Applications (PDF) (8-14-2008)

Clarification on EPA-FLM Recommended Settings for CALMET (PDF) (8-31-2009)

Use of Non-default Radius for Determining Surface Roughness Length for AERMET (PDF) (9-17-2009)



Questions concerning the memos should be directed to Tyler Fox, Group Leader, Air Quality Modeling Group, at fox.tyler@epa.gov.

Office of Air and Radiation | Office of Air Quality Planning and Standards

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