Tenth Circuit Decision Revives Groups’ Suncor Clean Air Act Lawsuit

Tenth Circuit Decision Revives Groups' Suncor Clean Air Act Lawsuit

Suit sent back to trial court to consider harm from Suncor refinery's pollution violations

Contacts

Perry Wheeler, Earthjustice, [email protected]

The Tenth Circuit Court of Appeals today ruled in favor of environmental justice and conservation groups in a lawsuit seeking to hold Suncor Energy accountable for repeated Clean Air Act violations at its Commerce City refinery. The citizen suit, filed in August 2024, alleges that Suncor has failed to control pollution emissions at its refinery, resulting in long-lasting harm to surrounding communities in North Denver.

"This decision is deeply personal," said Ean Thomas Tafoya, vice president of state programs with GreenLatinos. "My family lives in North Denver, and like so many of our neighbors and GreenLatinos members, we've lived with the impacts of industrial pollution for decades. Today's ruling is an important step toward ensuring our communities have the opportunity to hold polluters accountable when the government fails to hold them accountable themselves."

A District Court judge dismissed the groups' case in May 2025, finding that twenty-year-old settlements between the EPA and Suncor qualified as government enforcement of the violations and, as a result, barred the groups from suing. The Tenth Circuit disagreed with this ruling and decided that the District Court applied the wrong legal standard in its order.

"For decades Suncor has delivered extraordinary levels of toxic pollution to North Denver and been fined pennies," said Margaret Kran-Annexstein, director of Colorado Sierra Club. "The Court of Appeals recognized the right of community members to challenge violations to federal air regulations. When decision makers fail to enforce the law, we must be able to fight back."

The Clean Air Act guarantees that communities harmed by air pollution violations can participate in enforcing and stopping that pollution. If the government has failed to enforce the violations in court, members of the public can step in to file their own lawsuit. In the District Court ruling, the judge found the suit barred, despite the fact that the last time the government took the refinery to court for air pollution violations was an EPA suit over 20 years ago-before many of the limits that Suncor is violating even existed.

In the years since, the government has settled a handful of administrative actions to enforce Suncor's emissions violations. These settlements have proven ineffective. Settlements the Attorney General's office negotiated with Suncor in 2020 and 2024 have required Suncor to pay fines that are just a fraction of what the law allows and have failed to deter future violations.

"All Coloradans deserve clean air and honest enforcement," said Bobbie Mooney, staff attorney with 350 Colorado. "This decision brings us closer to the justice our communities have been denied for decades. This ruling is a victory for community power and a long-overdue check on Suncor's pollution."

The Tenth Circuit found that the District Court erred in concluding that all of the suit's claims were barred. Specifically, while it agreed with the District Court that the twenty-year-old settlements could, under certain circumstances, bar citizen-suit claims for violations of the "same" pollution limits, the District Court failed to evaluate whether the citizen suit involves the same limits covered by the government's suit.

Today's ruling will send the case back to the trial court to answer that question. If the District Court finds that the claims are the same, the Tenth Circuit further directed the District Court to scrutinize whether the government is enforcing those same limits diligently.

"We are grateful that the Court recognized that our clients are legally entitled to step in to stop Suncor's Clean Air Act violations," said Ian Coghill, senior attorney with Earthjustice's Rocky Mountain Office. "Many of the limits Suncor is violating did not even exist the last time the government went to court. Meanwhile, the administrative settlements negotiated behind closed doors have clearly done nothing to deter Suncor from continuing to violate its pollution limits. These violations have significant impacts on the communities surrounding the refinery and must at long last be addressed."

Suncor's pollutants pose an ongoing health threat to the refinery's neighbors, predominantly communities of color who are more likely to be economically disadvantaged. Residents of neighboring zip codes suffer disproportionately from high rates of asthma, cardiovascular disease, and diabetes.

Earthjustice represents GreenLatinos, the Sierra Club, and 350 Colorado in the lawsuit.

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