Center for Biological Diversity

For Immediate Release, November 17, 2023


Ryan Maher, (781) 325-6303,
Jeremy Nichols, (303) 437-7663,

Lawsuit Challenges EPA Approval of Denver Oil Refinery Air Permit

Unchecked Pollution From Suncor Energy’s Refinery Threatens Communities

DENVER— The Center for Biological Diversity filed a lawsuit today challenging the Environmental Protection Agency’s approval of an air pollution permit that allows a Suncor Energy oil refinery to release harmful amounts of nitrogen oxides and sulfur dioxide.

Under the Clean Air Act, the EPA must reject state-issued permits that fail to ensure compliance with federal air pollution standards. Today’s lawsuit asks the U.S. Court of Appeals for the 10th Circuit in Denver to compel the agency to object to the permit for Suncor’s refinery north of Denver.

“Suncor is getting a free pass to spew dangerous levels of air pollution,” said Ryan Maher, a staff attorney at the Center. “Even after the EPA flagged problems with the facility’s air pollution permit, the agency has continued to allow this refinery to poison the air people breathe.”

The lawsuit follows a petition filed in 2022 by a coalition of community and environmental groups urging the EPA to fix or reject Suncor’s state-issued permit. The groups included Colorado Latino Forum, GreenLatinos, Elyria and Swansea Neighborhood Association, Cultivando, Sierra Club and the Center for Biological Diversity.

In response to the petition, the EPA acknowledged the facility’s past violations and the state’s problematic approach to enforcing compliance but failed to take steps to ensure the permit would not continue to allow violations of federal air quality standards.

Suncor’s refinery is a large source of toxic air pollution that disproportionately harms communities of color in north Denver and neighboring Commerce City. Monitoring by the community group Cultivando has found that emissions from the refinery endanger local residents.

In the petition to the EPA, the coalition of community and environmental groups included independent expert air pollution computer modeling, as well as modeling from the state Air Pollution Control Division, which issued the Suncor air permit. In both cases the modeling showed that the Suncor permit allows violations of air quality standards meant to protect people from harmful nitrogen oxides and sulfur dioxide air pollution.

Suncor has a history of violating clean air requirements. In September the company settled with the EPA over ongoing air quality violations after fuel produced by Suncor resulted in illegal releases of hazardous air pollution, including carcinogenic benzene and ozone-causing volatile organic compounds. In the past decade, Colorado has taken nine enforcement actions over air violations at the refinery.

Despite the violations, Colorado Gov. Jared Polis and his administration continue to permit Suncor to pollute.

“Suncor’s refinery is just the worst, yet the Polis administration continues to look the other way and let the company put people and communities at risk,” said Jeremy Nichols, a senior advocate at the Center. “This lawsuit is about making sure the EPA no longer lets Colorado off the hook when it comes to holding polluters accountable.”

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

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