Out for Public Comment: April 28, 2019 Stratospheric Intrusion Exceptional Event Demonstration

The Wyoming Department of Environmental Quality – Air Quality Division (AQD) has notified EPA Region 8 that exceedances of the 8-hour ozone National Ambient Air Quality Standard collected at the Moxa, South Pass, Juel Springs, and Big Piney air quality monitoring stations on April 28, 2019 are proposed to be flagged as due to an exceptional event under 40 CFR 50.14, “Treatment of air quality monitoring data influenced by exceptional events.”  The AQD has produced a comprehensive demonstration in support of its notification to flag the exceedances cited above.  The AQD is soliciting comments from the interested public on this demonstration packet.  The demonstration packet is available for public comment and the public will be allowed a period of thirty (30) days to submit written comments.

Notice is hereby given that the State of Wyoming, Department of Environmental Quality, Division of Air Quality, proposes to flag this data as influenced by an exceptional event.

Comments can be submitted to the AQD's Monitoring Supervisor, Ms. Cara Keslar, Ambient and Emission Monitoring Supervisor, Air Quality Division, Department of Environmental Quality, 200 West 17th Street, 3rd Floor, Cheyenne, Wyoming 82002 or by fax to (307) 635-1784.  Comments may also be submitted electronically through the following website:  (http://deq.wyoming.gov/aqd/resources/public-comments-online/).  Comments submitted by email will not be accepted.  Interested parties may examine the documentation packet and relevant supporting materials on AQD’s website (http://deq.wyoming.gov/aqd/monitoring/resources/exceptional-events/).  This material may also be viewed online, at the above URL, by appointment to use a computer kiosk at the Department’s office locations in Cheyenne, Casper, Sheridan, or Lander.  In accordance with the Americans with Disabilities Act, special assistance or alternate formats will be made available upon request for individuals with disabilities.  Para espanol visite http://deq.wyoming.gov/.

Public comments must be received no later than September 24, 2020.  All comments received by the close of business on September 24, 2020 will be submitted to EPA’s Region 8 along with the demonstration packet to be considered in arriving at a final determination of treatment of data influenced by exceptional events and will be retained on file in the Cheyenne office.