Steam rises from Colstrip’s Unit 4. Unit 3 beside it was temporarily shut down for maintenance, while Units 1 and 2, left, were permanently shut down in 2020.
Steam rises from Colstrip’s Unit 4. Unit 3 beside it was temporarily shut down for maintenance, while Units 1 and 2, left, were permanently shut down in 2020. Credit: Kelsey Turner

This story is part of a 12-part investigation by the Chicago Investigative Project in the graduate program at the Medill School at Northwestern University.

This article was first published by Native News Online.

After a 10-hour Wednesday shift at the coal-fired power plant in the small southeastern Montana town of Colstrip, Northern Cheyenne tribal member Jason Small drives three minutes down the road to the local taco truck. Dressed in a zip-up hoodie and jeans, he grabs a burrito and heads next door for a late-afternoon beer at the Whiskey Gulch Saloon, a nearly empty bar where the staff all know him. 

Small has worked at the Colstrip Steam Electric Station for about 20 years. He’s a boilermaker, doing maintenance and repairs for the plant’s two remaining units. The other two units shut down in 2020 — two years ahead of schedule — because the units’ two owners, Talen Montana and Puget Sound Energy, could not cover their costs.

Colstrip has provided power to cities across the Northwest since the 1970s. Now, the plant’s future is uncertain. 

The plant’s closure would mean job losses for locals, including Small. But unemployment is not the only legacy the plant would leave behind: Questions remain about how five decades’ worth of coal ash — the toxic byproduct that contains dangerous elements like arsenic, lead and mercury — will be cleaned up.

Coal ash 101: Everything you need to know about this toxic waste

As coal plants close nationwide, they leave behind nearly a billion tons of toxic coal ash. The Medill School of Journalism spent months investigating the coal ash threat and how regulators, companies, and environmental groups are handling it. 

Here are the basics that will help you understand this looming threat.

What is coal ash?

Coal ash is the toxic byproduct of burning coal to generate electricity. It contains heavy metals that can contaminate groundwater, lakes, and rivers. 

Where is coal ash located?

Coal ash is stored in more than 700 ponds and landfills nationwide, most of them unlined. Ash can also be recycled — known as “beneficial reuse” — in which it is used to make concrete or build roads. 

What is the Coal Combustion Residuals (CCR) Rule?

In 2015, the EPA established rules for coal ash units, requiring companies to test groundwater, remediate contamination, and make plans to close the units. Companies have to post groundwater monitoring data and closure plans online.

The rule excludes hundreds of “legacy ash ponds” that closed before the federal rule took effect in 2015, yet these ponds are still causing serious groundwater contamination. The rule also does not cover coal ash that was over decades dumped and scattered around coal plant sites and even surrounding areas, often used to build up berms or fill in land.

Is coal ash contaminating our water?

Data posted by companies shows that contaminants around coal ash ponds frequently exceed limits set by the EPA, sometimes exponentially. Private wells used for drinking water can be and have been contaminated by coal ash. Rivers and lakes used for recreation and municipal water supplies can also be contaminated by coal ash.

What’s in coal ash?

Boron is linked to reproductive problems like low birth weight and is also toxic to aquatic life.


Lead is a potent neurotoxin linked to swelling of the brain and nervous system damage.


Lithium is linked to liver and kidney damage as well as neurological diseases and birth defects.


Arsenic is linked to nervous system damage and higher rates of cancer. 


Molybdenum is linked to gout, high blood pressure, and liver diseases. 


Cobalt is linked to thyroid damage and blood diseases.

How is a coal ash pond closed?

Coal ash sites need to close after getting their final shipment of coal ash, if they are polluting groundwater above certain standards, or if they fail to meet other safety criteria. The rules say all unlined ponds needed to stop accepting waste by April 2021, though some requested exceptions and have continued filling with coal ash. 

Cap-in-place closure

A protective cover is placed over the coal ash so rainwater doesn’t get in and cause flooding or increased leaching into groundwater.  If the coal ash is left in contact with groundwater or permeable rock, it can continue leaching contaminants even when capped.

Removal closure

Coal ash is excavated from a pond, dried, and moved to a lined landfill above the water table. Companies may be able to build a landfill on the power plant site. Shipping coal ash to landfills off-site means heavy truck traffic or shipping by barge or rail.

Who pays for coal ash cleanup? 

The owners of coal ash sites — utilities or power companies and their shareholders — can pay the cost of coal ash cleanup, often hundreds of millions or even billions of dollars across multiple sites. 


Utilities can seek approval from state public service commissions to bill the cost of coal ash cleanup to ratepayers. They can even seek a profit as a portion of the costs. 


If coal ash is designated a Superfund site, the EPA can make the responsible parties — utility or power companies — pay for the cleanup. The government can also pay for the cleanup from a pool of Superfund money, especially if the companies no longer exist or can’t pay. 

Compiled by Sruthi Gopalakrishnan.

Coal ash presents a serious environmental challenge, as well as threats to the spiritual and cultural history of Native Americans on the Northern Cheyenne Indian Reservation where Small lives. The 444,000-acre tract of land is home to about 5,000 enrolled Northern Cheyenne tribal members. Though Small has worked at various power plants around the country, including in Wyoming, Colorado, Washington, and Illinois, he prefers living close to home, on the land his ancestors fought their way back to after the U.S. government forcibly relocated them to present-day Oklahoma in the 1800s.

Northern Cheyenne tribal member Jason Small stands outside the Whiskey Gulch Saloon in Colstrip after his 10-hour shift at the plant.
Northern Cheyenne tribal member Jason Small stands outside the Whiskey Gulch Saloon in Colstrip after his 10-hour shift at the plant. Credit: Kelsey Turner

Under the federal Coal Ash Rule adopted in 2015, the Environmental Protection Agency requires plant owners to submit written closure plans detailing how coal ash will be safely stored. Over 700 coal ash units in 43 states and Puerto Rico are regulated under this law. Almost all of these units are polluting groundwater with unsafe levels of toxins, according to analysis by nonprofit groups Earthjustice and Environmental Integrity Project of documents filed by companies as required by the rule. 

The safest closure option is generally to remove coal ash from unlined ponds and place it in lined landfills. But many companies are proposing to close their unlined pits in place, capping the ash to prevent rainwater infiltration but leaving it in contact with the earth and often with groundwater. 

Colstrip, the second-largest coal-fired plant west of the Mississippi, has an enormous coal ash pond complex covering more than 800 acres. Colstrip’s coal ash is disposed of by mixing it with water and storing it in ponds at three areas near the plant. One of these areas — the Units 1 and 2 ponds — hold enough ash to fill over 2,000 Olympic-size swimming pools. They have been leaking sulfates, boron, selenium, and other toxic heavy metals into the local aquifer for decades, releasing 43,000 gallons of contaminated water per day, according to the state’s Department of Environmental Quality estimates.

The consequences of leaving coal ash in the groundwater here could be deadly, said Anne Hedges, director of policy and legislative affairs at the Montana Environmental Information Center. “There are dozens of contaminants. They cause cancer, they cause neurological disorders, they cause cardiovascular disease. These are not things you want to mess around with.”

Though the plant’s coal ash must be cleaned up and the ponds closed in accordance with the federal Coal Ash Rule, how exactly the cleanup happens remains to be seen.  

If done thoroughly, coal ash cleanup could provide Northern Cheyenne tribal members with much-needed jobs while repairing environmental damages. But if not properly disposed of, ash could contaminate an ancestral waterway and potentially the drinking water of reservation residents, adding to a legacy of broken promises between the Northern Cheyenne and the coal industry.

The dangers of coal ash

In the town of Colstrip, residents don’t drink groundwater; instead, their water is piped in from the Yellowstone River. But on the Northern Cheyenne reservation, which lies about 14 miles from Colstrip’s ash ponds, nearly all residents drink groundwater from tribal-owned wells.

If ash continues leaking into the aquifer, some residents fear it could flow toward the reservation. The Montana Department of Environmental Quality, the state regulatory agency responsible for ensuring Colstrip’s groundwater contamination is addressed, believes this to be a “very unlikely” outcome. Most contamination so far has been contained close to the pond sites with a system that captures polluted water, said DEQ’s Colstrip Environmental Project Officer Sarah Seitz. 

But if the technology breaks down or is not properly maintained, contamination could spread further. This issue is not new for Talen. In 2019, Talen Energy agreed to pay a $1 million fine to compensate for coal ash contamination from leaking ponds at its Brunner Island plant in York Haven, Pennsylvania. 

Small said community members are concerned about coal ash, “and rightfully so.” It’s especially worrying for ranchers, who fear polluted groundwater could make their animals sick. “I have cattle and stuff, too,” Small said. “I would say nobody wants the contaminated groundwater.”

Northern Cheyenne Tribal Administrator William Walksalong fears coal ash’s many unknown consequences. He worries coal ash could flow into the nearby Armells Creek, an ancestral waterway that supports more than 15 agricultural businesses downstream from the Units 1 and 2 ash ponds, according to the local conservation group Northern Plains Resource Council. Colstrip currently has a pump-back system in place to prevent ash from reaching the creek.

“The long-term environmental impacts are what concerns me,” Walksalong said. “That’s our land. That’s our ancestral homeland.”   

A herd of mule deer walk through Colstrip’s residential neighborhood.
A herd of mule deer walk through Colstrip’s residential neighborhood. Credit: Kelsey Turner

Toxic legacies and broken promises

The herds of deer that wander Colstrip’s streets seem to have grown used to the plant’s steady presence in the community. Steam billowing from its two remaining units is simply a part of life, blending into puffy clouds drifting through Big Sky Country. 

But local tribal members and environmentalists see the plant and the coal ash as a serious threat to wildlife and natural resources, and they are fighting to make sure the coal ash is removed and the area fully remediated. 

Talen Montana, as the plant’s operator, is responsible for developing “remedy alternatives” for coal ash. The Montana DEQ selects a remedy and directs Talen to design a plan to carry it out. DEQ has already selected remedies for all three pond areas, allowing Talen to leave the ash in place for some ponds and requiring full removal for others. Local environmental groups, however, are concerned about Talen’s plans for the ponds at Units 1 and 2. Some ash in these ponds sits directly in the groundwater, making it easy for contamination to spread. 

Northern Cheyenne tribal member Alaina Buffalo Spirit drinks groundwater from a private well near her home on the reservation. “My fear is that in the future, that the [contaminated] water could essentially go underneath and eventually come towards our lands,” Buffalo Spirit said. 

A member of the Northern Plains Resource Council, Buffalo Spirit advocates for a “high and dry” cleanup plan for the Units 1 and 2 ponds. This means coal ash would be fully dug up and moved to a new, lined landfill on Talen property.

In 2020, DEQ selected a remedy directing Talen to do just that. Talen, however, disputed the agency’s decision, claiming DEQ had chosen the most expensive remedy despite other proposals meeting environmental requirements at lower costs. The company prefers to remove only the ash closest to the water table and relocate it to different parts of the ponds, while also installing technology that dries the ash and treats contaminated water, among other remediation actions.

Ultimately, DEQ reached a settlement with Talen last October. Though the settlement requires Talen to continue planning for full removal, it also gives the company two years to propose another, potentially less rigorous, plan for handling coal ash. 

This settlement leaves the “high and dry” plan in “serious jeopardy,” Hedges said. “The state left the door open for Talen to come back with a weaker cleanup plan.” 

Adding to the uncertainty, Talen Energy filed for bankruptcy in May, citing $4.5 billion of debt, the Billings Gazette reported. This is alarming for environmentalists like Hedges who think the financial assurance Talen is required to pay DEQ for ash cleanup is not enough to cover the cleanup costs should Talen disappear. DEQ currently holds over $306 million in bonds for financial assurance, and does not foresee Talen’s financial situation affecting its cleanup responsibilities, according to DEQ officials. Talen Energy did not respond to requests for comment.

The Northern Cheyenne tribe supports the full removal of coal ash not only for environmental and health reasons, but also for the jobs it might provide — jobs that will be even more needed if the plant closes. The reservation has an unemployment rate of 13.3%, and less than half of the reservation’s population over 15 is employed, according to the U.S. Census Bureau. As of 2019, the tribe calculated that if the Colstrip facility closes, about one in five Northern Cheyenne tribal members’ jobs would be lost.

Republican state Sen. Duane Ankney worked for many years as superintendent at a mine near Colstrip that provides coal for the plant. He knew that each Native worker he oversaw was often supporting multiple families back on the Northern Cheyenne reservation or the adjacent Crow reservation. “When a young Crow or Northern Cheyenne man works overtime, he’s probably buying Pampers for three families,” Ankney said. “It’s not driven by his wanting a brand new fancy pickup. It’s driven by his family’s needs.”   

Houses across the street from the Northern Cheyenne capitol building in Lame Deer.
Houses across the street from the Northern Cheyenne capitol building in Lame Deer. Credit: Kelsey Turner

Tribal Administrator Walksalong has encouraged Talen to employ tribal members in its remediation plans, which could take decades to complete if the ash is fully removed. “When you do the mitigation of shutting down and cleaning those coal ash ponds, include the Northern Cheyenne people,” he said. “Those people that are unemployed because they’re shutting that place down, retrain them.”

An analysis by the Northern Plains Resource Council found that if Talen were required to carry out full coal ash removal at the Units 1 and 2 ponds, along with groundwater treatment and aggressive remediation at some of the plant’s other pond areas, an average of 400 jobs per year would be created in the first 10 years. These jobs could partially offset those lost if the plant closes while also protecting the environment, a scenario Northern Plains calls a “true win-win.”

Small, however, thinks coal ash cleanup’s employment impacts will be “negligible” for the tribe. The local coal industry employs about 100 tribal members, including at the Colstrip plant, the nearby Rosebud Mine, and the much smaller Colstrip Energy LP plant about 6 miles north of town, according to the Southeastern Montana Development Corporation. 

Northern Cheyenne Tribal Administrator William Walksalong stands beside a painted buffalo skull, a piece of artwork belonging to his nephew that Walksalong keeps in his office. The painting depicts a man smoking a ceremonial pipe.
Northern Cheyenne Tribal Administrator William Walksalong stands beside a painted buffalo skull, a piece of artwork belonging to his nephew that Walksalong keeps in his office. The painting depicts a man smoking a ceremonial pipe. Credit: Kelsey Turner

“The older generation of Cheyennes, there were quite a few that worked the mines and the plants,” Small said. “They’ve died off and there haven’t been that many who necessarily go into that line of work again. And I don’t think ash cleanup is going to drag them back.” 

Similarly, while Walksalong supports job creation, he is also skeptical that these jobs will provide substantial economic opportunity for tribal members. After all, this was the same promise made to them back when the Colstrip plant first opened in 1975. “They promised us jobs, spin-off businesses, things like that,” Walksalong said. “That really hasn’t happened.”

Nearly 30% of people on the Northern Cheyenne reservation live below the poverty level, according to U.S. Census data. Some reservation residents live in battered trailers and houses cramped with several generations of family members. Others live in spacious single-family homes. “Those are the people that have worked at Colstrip,” said Rae Peppers, general manager for the Northern Cheyenne Utilities Commission.

Crow tribal member Rae Peppers sits at her desk in the Northern Cheyenne Utilities Commission, where she was working on a grant application for funding from the Montana Coal Board. Peppers has lived on the Northern Cheyenne reservation for 40 years.
Crow tribal member Rae Peppers sits at her desk in the Northern Cheyenne Utilities Commission, where she was working on a grant application for funding from the Montana Coal Board. Peppers has lived on the Northern Cheyenne reservation for 40 years. Credit: Kelsey Turner

As a result of a 1980 agreement between the Northern Cheyenne tribe and the plant’s then-owner Montana Power Company, tribal members have hiring preference at Colstrip. Yet despite this agreement, unemployment rates on the reservation tripled between 1970 and 1990, while the poverty rate increased to almost five times the rate of other Rosebud County residents, according to the Sierra Club’s analysis of federal data.

While coal ash removal would create jobs that could theoretically decrease unemployment among tribal members, there are systemic reasons why Colstrip has historically failed to bring prosperity to the reservation, Walksalong pointed out. For him, job creation through coal ash could be just another empty promise made by the coal industry. “Right now, I think there’s a movement amongst our people to not get taken by these false promises of jobs and economic stimulation in this area,” he said. 

Tribal members cite a variety of reasons why some Native people choose not to work at Colstrip. One reason is drug testing. Substance abuse is widespread on the reservation, and some people do not apply for work because they know they could not pass a drug test, Peppers said. 

Another reason is that tribal members do not want to face the workplace discrimination they say they’ve experienced at the plant and mine. “I think they pushed a lot of our people out because of that institutionalized racism in their company down there,” Walksalong said.

Peppers, an enrolled member of the nearby Crow tribe who has lived on the Northern Cheyenne reservation for 40 years, worked as a secretary at Colstrip when she was younger. While there, she felt her boss treated her poorly. “I just walked away from the job and quit,” she said. “And that’s what a lot of people here tend to do.” 

Colstrip Mayor John Williams, a non-Native man, noted that Colstrip provides other benefits in addition to jobs. As part of the 1980 agreement with the tribe, Colstrip Power Plant offers full-ride college scholarships to two tribal members per year, given the student plans to study a subject related to energy development. And schools in Lame Deer — about 20 miles south of the plant where the Northern Cheyenne tribe is headquartered — have gotten funding from Montana’s Coal Board, which provides grants to communities, school districts, and tribal governments for needs related to coal development. 

While Peppers agrees coal ash cleanup would create employment for those on the reservation, she also thinks Native people in the area should not rely on Colstrip for economic opportunity. If the plant shuts down, she’s confident that tribal members would find new ways to support themselves. “Just look at our history of everything that has happened to Native [people],” she said. “We pick ourselves back up and continue.”  

‘Blood flow of the living earth’ 

Tom Mexicancheyenne was in his early 60s when he began receiving messages from what he calls “the sacred ones.” After going through a rough few decades of relationship troubles and healing from drug and alcohol use, Mexicancheyenne suddenly felt a profound urge to be in nature. 

Every day, he would go out to his backyard and stand among the trees alongside a creek. There, he would talk to the spirits. “The trees speak to one another, the plants, the insects,” he said. 

He believes that generations ago, Cheyenne people were more in touch with their connection to the earth. “But because of what we went through — assimilation, alcohol back then, and eventually now it’s drugs, too — we’ve lost those teachings, many of us. But I know we can get them back.”

To do so, Mexicancheyenne says he continues speaking for the water that cannot speak for itself — and that is being put at risk by human activities. 

“We’re disturbing the natural blood flow of water,” he said. “The blood flow of the living earth. If we disturb that, of course it’s going to do something. It’s going to cause contamination.”

The northern boundary of the Northern Cheyenne reservation after a late-April snowstorm.
The northern boundary of the Northern Cheyenne reservation after a late-April snowstorm. Credit: Kelsey Turner

Mexicancheyenne normally drinks groundwater supplied by the town of Lame Deer. As a young man, he got a job with the tribe doing test drilling for coal. “I would go out every day and work with these rigs, and they would drill in the ground,” he said. “I didn’t know what they were doing. I just knew that I needed to work.” 

They put chemicals into the ground and hit underground springs while drilling, he said. “As a Cheyenne man — and there are other tribes, many tribes that believe this, too — you never do anything to the earth. You never destroy it. You’re not even supposed to dig it up. That was the teachings that we learned.”

He worries Talen’s preferred plan for dealing with coal ash would similarly harm the earth. Now an at-large board member of the Northern Plains Resource Council, Mexicancheyenne advocates for full removal of Colstrip’s coal ash before the area’s groundwater situation gets even worse. “If we don’t stop what we’re doing, things are going to change,” he said. 

Walksalong feels Colstrip has “completely ignored” the Northern Cheyenne’s opinions on coal ash remediation. “I even asked to go down there and tour those coal ash ponds. They never did invite me, never did follow up,” he said. 

After working to protect Cheyenne homelands from environmental harms for the last 30 years, Walksalong is ready to move past coal. “I want to be part of that movement of people that put an end to this coal giant that took no consideration of the Northern Cheyenne people, our environment and the effect on our health.” 

He remembers American developers arguing with him when the tribe opposed coalbed methane development in the early 2000s. “Don’t you Northern Cheyennes understand? You could get rich!” he recalls them saying. 

Walksalong emphasizes that money isn’t everything. As coal booms and busts, developers and energy companies come and go from the area. Meanwhile, the tribe is left to protect their ancestral land from coal’s long-term consequences, like coal ash pollution.

“Those of us that live here have deep roots,” Walksalong said. “We buried our people on these lands here, held ceremony here, built our homes here, farmed here, ranched here. Our souls are here on this land.”

Kelsey Turner is a recent Medill School of Journalism graduate whose writing focuses on social justice issues facing minority communities. Kelsey has written for publications including Native News Online, South Side Weekly and Restoration Magazine. She now reports on affordable housing and homelessness for The Columbian, a local newspaper in Vancouver, Washington.