Ozone information

Colorado is continuing efforts to reduce ozone air pollution. High levels of ozone present health concerns for healthy adults and for sensitive people, particularly the elderly, young children and those with asthma or other respiratory ailments. Symptoms include:
  • Stinging eyes and throat.
  • Chest pains.
  • Coughing.
  • Breathing difficulty. 
The Denver-Metropolitan and North Front Range areas have a history of violating the national ozone standards. The region has violated older, less stringent standards since the 1970’s and throughout the 2000’s. With EPA’s promulgation of the more stringent 2008 standard of 75 parts per billion, the area was designated as a marginal “nonattainment area” for ozone in 2012, and later reclassified as a moderate nonattainment area in 2016.  The EPA has since adopted a more stringent standard of 70 parts per billion, in 2015. As a result, Colorado is required to develop plans to reduce ozone levels to meet both standards.

A revised State Implementation Plan (SIP) for the 2008 standard to reduce ozone levels was developed by the Air Pollution Control Division and the Regional Air Quality Council and approved by the Air Quality Control Commission on November 17, 2016. The plan included a detailed technical analysis of the formation of ozone, future trends in ozone levels, and strategies to reduce ozone. Documents related to this rulemaking can be found on the Air Quality Control Commission’s website. Colorado must comply with the 2008 ozone standard by 2018, and the SIP included the measures necessary to meet the deadline. A SIP revision will also be developed in the future to meet the 2015 standard, and will rely on much of the groundwork already done. EPA will likely designate the Denver and North Front Range areas in 2017 as "nonattainment" for the 2015 standard. Colorado will then have three years from the date of designation to submit a revised SIP to EPA showing how it will meet the 2015 standard.
Nonattainment area planning
The Regional Air Quality Council is currently evaluating control strategy options for the Denver Metro/North Front Range 8-Hour Ozone Nonattainment Area. In support of this effort, the Air Pollution Control Division is initiating an early stakeholder process to consider potential Air Quality Control Commission rule revisions. 

The Division is currently accepting comments on potential rule revisions to align Regulation Number 7 with EPA’s Oil and Gas Control Techniques Guideline (CTG) and establish additional oil and gas control measures.

2017 Stakeholder Meetings:
Information pertinent to industry
EPA's proposed National Ambient Air Quality Standards (NAAQS) for ozone
Collaborating agencies