Winter Ozone

In 2005, the AQD recorded elevated ozone levels in the Upper Green River Basin. We know that the ozone exceedances are related to at least four factors: adequate amounts of precursor chemicals, snow cover, temperature inversions and low winds, and sunlight.

In the time since then, DEQ has been working to lower the ozone levels, conducting a series of studies on the area. This page is intended to provide the public and industry with information about past and current work, background information related to the ozone issue, current ozone data, technical documents and forms. 


Primary Point of Contact to Improve Communication

In response to input received from the public, the DEQ is implementing a plan to improve communication relating to ozone and the Upper Green River Basin.  Brian Hall, DEQ Outreach Program Manager, will be the primary point of contact.  Brian will serve as the point of contact with respect to calls, emails and fulfillment of data requests relating to ozone and the Upper Green River Basin.  Brian can be reached at or (307) 777-7753.  Click Here to file a Records Request.


Thank You Ozone Contingency Plan Program Participants

The DEQ would like to thank all of the 2017 Winter Ozone Season Ozone Contingency Plan program participants.  The Ozone Contingency Plan program continues to be a success due to participant support and effort to implement emission-reducing efforts on Ozone Action Days.  The DEQ will outreach to all stakeholders to continue to expand the Ozone Contingency Plan program for the 2018 Winter Ozone Season.

Anadarko Petroleum Corporation   Merrion Oil and Gas Corporation
Anticline Disposal   Mustang Resources LLC
BLM - Pinedale   Oil Well Perforators, Inc.
Breitburn Operating LP   Omimex Petroleum Inc.
Bridger-Teton National Forest   Phillip T. Sharples Trust
Caerus Northern Rockies LLC   Plains All American Pipeline
Denbury Onshore, LLC   Plains Marketing
Dominion-Questar   QEP Energy
Enterprise Jonah Gas Gathering   Synergy Operating, LLC
EOG Resources, Inc.   Tesoro Logistics
ExxonMobil USP   True Oil LLC
Foundation Energy Management, LLC   Ultra Petroleum
GMT Exploration   Urban Oil and Gas
Hilcorp Energy   Vector Minerals Corporation
Huntington Energy LLC   Warco Pump Service, Inc.
Jonah Energy LLC   Williams Field Services
Linn Operating Inc.   WY Department Of Transportation
Lower Valley Energy    


Ozone Action Day Notifications

AQD will provide the community with Ozone Action Day notifications when they are issued.  AQD will issue an Ozone Action Day one day in advance when forecast weather conditions appear favorable for the formation of elevated ozone the following day.  Ozone Contingency Plans should be implemented upon one-day notice and everyone is encouraged to voluntarily reduce emissions. Please remember that current information on ozone levels at the AQD’s monitoring stations can be found at

Note: AQD winter ozone forecasting only takes place from January through March of each calendar year. 

For more information about Winter Ozone Updates, please call 1-888-WYO-WDEQ.


2017 Winter Ozone Season Update