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Air Quality Lawsuit Filed in Colorado Targets Ozone and Oil and Gas Production

February 17, 2023

On January 23, the Center for Biological Diversity made good on its threat to sue EPA for its approval of Colorado’s State Implementation Plan (SIP) amending the state’s programs for New Source Review and Air Pollution Emission Notices. See Petition for Review filed in the Tenth Circuit Court of Appeals here.

The Center had submitted a 60-day-notice of intent to sue on July 5, 2022, and has been engaged with EPA and other stakeholders since then attempting to address the issue. The SIP amendment in question addressed Clean Air Act Section 182(c) requirements for the Denver Metro/North Front Range Serious nonattainment area under the 2008 Ozone NAAQS. See an earlier blog on the topic from this author here.

EPA approved the SIP revisions in its final action published in the Federal Register on November 22, 2022, that accepted the repealing and addition of new and revised rules to Colorado’s air quality Regulation 3 that were submitted by the State of Colorado on May 13, 2020.

Stressing that the lawsuit is aimed at “forcing the EPA to crack down on this dangerous pollution,” the Center’s senior attorney, Robert Ukeiley, focused on the oil and gas industry stating: “Colorado can’t keep letting more and more oil and gas wells spew their pollution if we’re going to have any hope of fixing our severe smog problem.” The Center’s challenge alleges that the SIP amendments submitted to the EPA by Colorado’s Air Pollution Control Division to address ozone exceedances in the region include loopholes that allow unlimited air pollution from drilling and fracking.

This post was drafted by John Watson, an attorney in the Denver, Colorado office of Spencer Fane LLP. For more information, visit