When the EPA rolled back toxic air rules regulations, it left this community in the path of pollution | 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 like lead and arsenic. These heavy metals can settle in water and be ingested by the fish. Mercury pollution, in particular, used to be much more prolific around the country, before Obama-era rules cut it dramatically, by 90%. Under a dozen other power plants around the country 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. Colstrip burns sub-bituminous coal, which contains smaller amounts of mercury as well as other toxic metals. Under former President Joe Biden, the Environmental Protection Agency attempted to crack down on the remainder, finalizing a regulation in 2024