When the EPA rolled back mercury regulations, it left this community in the path of pollution

By Ella Nilsen, CNN

(CNN) — Rainbow trout is a prized catch for fisherman on the Northern Cheyenne reservation, in the high plains of southeastern Montana.

“The men in my family like to go fishing; they cook them right there because it’s fresh,” said Charlene Alden, the tribe’s environmental protection director.

But there is an invisible threat in the local waterways. The pollution coming out of the smokestacks at the nearby Colstrip power plant contains mercury and other toxic elements, which can settle in water and be ingested by the fish.

That kind of pollution used to be much more prolific around the country, before Obama-era rules cut it dramatically, by 90%. But Colstrip is among over 30 power plants nationwide that still burn lignite, a peat-rich coal that contains higher-than-average levels of mercury and other pollutants — and lignite plants were able to slip through a loophole in the Obama regulations.

Under former President Joe Biden, the Environmental Protection Agency attempted to crack down on the remainder, finalizing a regulation in 2024 that closed the prior loophole. But the Trump administration recently axed that measure, with EPA Press Secretary Brigit Hirsch calling the original Obama rule “highly effective” and one that has “protected public health and the environment for years.” In other words, to the current EPA, a 90% reduction is good enough.

While it’s true the Trump rollback impacts a relatively small number of power plants, it could have big implications for communities that live near them, like the Northern Cheyenne tribe.

Alden said she is concerned about what they mean for the health of her community.

“I think it’s taking a step backwards from making sure our environment is safe and making sure our food sources are safe,” Alden said. “We try hard to keep our little piece of land that we have left free of pollution. We consider ourselves stewards of the environment.”

An ‘insidious toxin’

Colstrip emitted nearly 60 pounds of mercury last year, according to EPA data mapped by the nonprofit Environmental Defense Fund. That heavy metal gets emitted into the air before bioaccumulating in land and water.

Mercury “is an insidious toxin,” said Joe Goffman, who led EPA’s Office of Air and Radiation under Biden. “It gets deposited in water, ingested by fish, and then people who eat the fish absorb it into their bloodstream.”

The metal is of particular concern to pregnant women, babies and small children, because it is a neurotoxin that can impact brain development and cause lung disease.

When the Trump EPA announced its rollback, the agency’s Deputy Administrator David Fotouhi said in a statement that the Trump changes were “fully protective of human health risks.”

But Harvard University research disputes that —– finding elevated levels of mercury in states such as North Dakota and Texas, where power plants still burn a lot of lignite coal. The paper shows smaller hotspots around the country near other coal-fired power plants that burn lignite, including Colstrip.

The Trump administration is “saying it’s small and costly, so it’s no big deal. But for those communities, it does matter,” said Elsie Sunderland, a professor of environmental chemistry at Harvard University who oversaw the research.

In addition, Sunderland and Goffman said, Native American tribes like the Northern Cheyenne are at particular risk because of their traditional diet.

“People who are recreational fishers or subsistence anglers do eat a lot of fish, compared to the national average,” Sunderland said.

Alden, the environmental protection director for the Northern Cheyenne, said mercury pollution has improved in the nearly 20 years she’s held her job. And her community has a complicated relationship with Colstrip. The power plant is a source of local jobs, and the tribe gets funding from the power plant to monitor the air quality in the area. But with cancer cases on the rise, she worries about the myriad health impacts from the smog coming out of Colstrip’s smokestacks.

“We’re losing our people younger and younger due to diseases, different types of illnesses,” Alden said, adding this is compounded by long wait times to see doctors.

A polluting plant

Colstrip has the unique distinction of being the nation’s dirtiest power plant; it emits the highest levels of soot in the United States and has not followed other plants in installing basic pollution control technologies on its two operating units, which have been running for the last four decades.

The Montana plant does emit less mercury pollution than others. The Oak Grove power plant in Texas and Coal Creek plant in North Dakota each emitted around 250 pounds of mercury — the most in the nation, while several other plants in the two states emitted over 100 pounds. Reducing mercury pollution at these kinds of plants would require using conventional pollution controls like scrubbers and baghouses, as well as injected carbon.

But last year, Colstrip sought and was granted a waiver from EPA to bypass the Biden-era pollution rules that remained in effect. And now, Trump officials have done away with the previous administration’s mercury air toxics rule, altogether. Spokespeople for the electric utility and power generator that own Colstrip didn’t respond to CNN’s requests for comment.

In its final rule rolling back the Biden-era regulation, the Trump EPA said upgrading these pollution controls would pose tremendous costs, saying Colstrip accounted for “almost half” of the overall, nationwide costs of compliance. Given how effective the Obama-era regulations already were, the agency has said it didn’t think this expense was worth the limited risk reduction.

The agency “is committed to ensuring clean air for all Americans regardless of race, gender, creed, or background,” said Hirsch, the EPA press secretary.

But Goffman, the Biden EPA official, said closing a loophole for lignite plants in 2024 did not seem like much of a stretch, because the technology to cut down on pollution was widely available.

“More than 90% of the rest of the coal fleet was reducing its mercury emissions by 80 or 90%,” Goffman said, adding the Biden administration determined the carveout for lignite-burning plants was no longer difficult to achieve.

And Goffman argues there are still major health impacts to the local communities.

“When they say, ‘a small rollback,’ there’s a population of actual communities and actual people who are being erased by that rhetoric,” Goffman said.

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