An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Environmental Modeling Community of Practice

ACE Release Notes

Version: 2.0

Corrections & Improvements to Prior Versions

  • Released by the EPA National Health and Environmental Effects Research Laboratory (NHEERL) in December 2003.
  • Distributed by the EPA Center for Exposure Assessment Modeling (CEAM) in April 2006.