DENVER — A federal appeals court is deciding whether to bring back a lawsuit by environmental groups against Suncor over ongoing pollution violations. 

Colorado GreenLatinos, Sierra Club and others sued the energy company in 2024, claiming state and federal regulators weren’t doing enough to protect people living near Suncor’s refinery in Commerce City. A federal district court dismissed the case, agreeing with Suncor that Colorado has been enforcing its pollution laws and citizen groups don’t need to get involved. 

Attorneys with Earthjustice, representing the environmental groups, argued Wednesday in front of the Tenth Circuit Court of Appeals in Denver that they should be allowed to sue the company because regulators aren’t doing their due diligence. Under the Clean Air Act, any citizen can sue a polluter in federal court unless the government is already suing the polluter for the same reasons. 

Suncor argued that there has already been diligent prosecution against the company’s violations through consent decrees.

“The same standards are applicable throughout both the consent decrees and the consent decree enforcement actions,” Hugh Gottschalk, an attorney for Suncor, said in court. “Five actions that have been taken in the last five years, all of which recite that we are enforcing the consent decree from years back.”

Ian Coghill, an attorney with Earthjustice, said in an interview with 9NEWS on Thursday that the cases against Suncor are no longer active and involve different violations. 

“These settlements are over 20 years old,” Coghill said. “They haven’t gone back to court at any point. So it’s not like these settlements are actually being actively enforced by a court in any way.”

State regulators have continually fined Suncor for repeated air permit violations. In 2024, the Colorado Department of Public Health and Environment fined Suncor more than $10.5 million, marking the largest such settlement ever in the state.

Lawyers for the environmental groups argue the fines aren’t doing anything to stop the pollution because Suncor just treats the fines as a business expense. 

“They make billions and billions in profit every single year. A few million dollars isn’t really going to change that,” Coghill said. “And so if Suncor has to pay $2 million in fines every three or four years, or something along those lines, you know, it seems that that may just be a cost of doing business to them.”

The plant exceeded pollution standards and limits over 1,000 times between 2019 and 2023, the groups said. The violations include exceeding limits or standards on hydrogen sulfide, carbon monoxide and sulfur dioxide.

Lawyers for the environmental groups said people living in the lower-income communities surrounding the refinery in Commerce City experience chronic health issues related to the pollution, including respiratory issues, headaches and cardiovascular problems.

“Suncor is contributing to a lot of that air pollution that’s in the area, and the folks there suffer,” Coghill said.

If the appeals court revives the case, the environmental groups want the district court to force Suncor to find out why its refinery is violating pollution limits and make changes to fix it. 

“Whether it’s installing additional controls or upgrading facilities or things along those lines, to kind of get to the root cause of the problem,” Coghill said.

It will likely take months to get a decision from the appeals court.