Wildfire-Influenced Ozone Exceptional Event Demonstration – Comments Due by May 9, 2018

Wildfire-influenced ozone exceptional events occurred in the Denver Metro area on 9/2/2017 and 9/4/2017. Ozone on these two days exceeded National Ambient Air Quality Standards.

The Clean Air Act allows for States to request to have data that are directly due to an exceptional event to be excluded from use in air quality determinations. Accordingly, the Colorado Department of Public Health and Environment (CDPHE) – Air Pollution Control Division (APCD) has developed an Exceptional Event demonstration for submittal to the U.S. Environmental Protection Agency (EPA)  for ozone on select sites in the Denver metro area on these two days.

The “Technical Support Document for the September 2 and 4, 2017, Ozone Exceptional Event” demonstration is available for review at:

The APCD is accepting public comment through 5:00 p.m. on May 9, 2018.  Comments should be sent to: cdphe.commentsapcd@state.co.us