AERMOD Update

September 6, 2006

The EPA promulgated AERMOD (AMS/EPA Regulatory Model) as a preferred guideline model in Appendix W of 40 Code of Federal Regulations (CFR) Part 51 on November 9, 2005. This promulgation became effective on December 9, 2005. Revision to the Iowa Administrative Code to adopt the revised Appendix W by reference became effective on August 23, 2006. As of August 28, 2006 the department is conducting internal modeling analyses with AERMOD.

Industries and their consultants can continue to submit modeling analyses conducted with either ISC3 or AERMOD during the one year transition period ending December 9, 2006. After December 9, 2006 regulatory use of ISC3 will require prior approval.

Questions related to AERMOD should be directed to the Air Quality Bureau's Modeling Group by contacting (515) 242 5100.