Elaine Steele’s house sits on a hill just above where 5.4 million cubic yards of coal ash spilled after a dike containing the pond ruptured at Tennessee Valley Authority’s Kingston power plant in Roane County, Tennessee, in December 2008. For months later, she watched as men and women workers cleaned up hundreds of acres of thick, toxic gray sludge.

She told The Daily Beast they dug out “iceberg-sized” mounds of coal ash, a toxic byproduct of burning coal, to clear roads and trees and find buried homes. The workers she saw were always covered in the sludge from head to toe. “We’d see them out working day and night, and I never once saw anyone wearing protective gear,” Steele said.

The Kingston spill is one of the worst environmental disasters in U.S. history. Coal ash, which contains toxic metals like mercury, arsenic, and cadmium, smothered the water and soil in rural Roane County, and a decade later, residents like Steele are still unaware of whether the toxins have been removed—or if they ever will be.

The long-term effects of the spill on those exposed to the ash cleanup are clear, however. In 2013, more than 30 current and former workers and some spouses filed a lawsuit in U.S. district court against Jacobs Engineering, a company hired to oversee cleanup efforts, claiming the company knowingly exposed the workers to the toxic coal ash. Other workers and their families keep coming forward. In March, 180 new cases of dead and dying workers who had cancer, heart disease, lung disease, and other conditions from working for months or years cleaning up the spill were recently filed in Roane County Circuit Court. The death toll is now more than 30, and those who fell ill have reached at least 200, according to an ongoing investigation by the Knoxville News-Sentinel.

“ It’s shocking how many different bodily organ systems these can affect. ” — Barb Gottlieb, director of environment and health for the Physicians for Social Responsibility

In the years since the spill, there’s been a widespread effort by communities around the U.S. to get utilities to clean up coal ash. To date, utility companies have excavated or committed to excavate about 90 million tons, Holleman said, but that’s just a drop in the bucket: in 2014 alone, the U.S. produced 140 million tons of it, according to the EPA. Many utilities mix the ash with water and run it into lagoons or ponds nearby, held in by a dike usually made from earthen material, and others dump the fly ash in landfills. A recent analysis by utility companies showed evidence of groundwater contamination at more than 70 of these sites around the U.S.

“The EPA estimates that these sites are responsible for at least 30 percent of all toxic pollution coming from industrial pollution,” Frank Holleman, senior attorney for the Southern Environmental Law Center, said. “[The Southeast] is much higher because we have more than our share—almost every major river system in Southeast has one or two facilities near it.”

Despite overwhelming evidence that coal ash is a major health risk, President Trump’s administration is prepared to roll back federal regulations on the disposal and maintenance of coal ash, giving more power to states to decide how and where to store coal ash and how to clean up spills and leaks. Last month, Environmental Protection Agency chief Scott Pruitt announced the agency will move forward with more than a dozen changes to the the 2015 Coal Combustion Residuals rule—the first time the federal government finalized regulations for coal ash disposal. The EPA claims the changes will save the utility sector “up to $100 million per year in compliance costs.”

Pruitt claims the revisions will allow for public comment and flexibility for state regulators, but his agency just dismissed a lawsuit about the health impacts of coal ash, citing “insufficient evidence” Alabama regulators violated the Civil Rights Act by allowing a landfill company to operate in a black community. During the Kingston cleanup, 4 million tons of coal ash was shipped to a landfill in Uniontown, Alabama, a predominantly black town. Since then, Uniontown residents had been fighting the legal battle with state and federal environmental regulators.

“What we’ve seen over and over again is that when we have fuzzy flexibilities, utilities take advantage to delay any decision on what they have to do,” Holleman said. “It puts maximum political pressure on the state agencies.”

The communities who live and breathe adjacent to coal ash ponds or landfills know the risks all too well, but these facilities have ripple effects throughout the regions they’re located in. Since coal ash is not counted as a hazardous waste and is minimally regulated, there are many possibilities for exposure, Barb Gottlieb, director of environment and health for the Physicians for Social Responsibility, told The Daily Beast.

“ What we’ve seen over and over again is that when we have fuzzy flexibilities, utilities take advantage to delay any decision on what they have to do. ” — Frank Holleman, senior attorney for the Southern Environmental Law Center

The toxins—such as lead, mercury, and radium—can leak into drinking water and contaminate the air miles from where facilities are located. Arsenic, also found in coal ash, is particularly dangerous when it penetrates skin or is ingested, as it can lead to heart disease and diabetes, as well as bladder, lung, kidney, and skin cancer. Chronic exposure to cadmium in drinking water can result in kidney disease and obstructive lung diseases like emphysema, bone mineral loss and osteoporosis. Drinking water laced with chromium can cause stomach ulcers, and breathing in the toxin can lead to lung cancer.

“It’s shocking how many different bodily organ systems these can affect,” Gottlieb said.

The chemicals can also be spread in other ways. Through “beneficial use” policies, the coal industry is allowed to reuse coal ash in some concrete and other construction projects instead of storing it, which has caused its own host of problems. In Town of Pines, Indiana, for example, the product was used so extensively in building roads and building material, the town was declared a Superfund site. A golf course in Chesapeake, Virginia partially built with coal ash led to a years-long legal battle with Dominion Energy over environmental contamination.

“It’s hard for people to put the pieces together,” Gottlieb said. “How often are people informed about toxic substances? And some of the harm that will result happens years later, making it harder to determine what was the cause.”

Steele said the thought of the damage coal ash caused her community and neighbors weighs on her. She moved to Roane County before the spill to retire and enjoy life on the water; she loves to kayak on the nearby Emory River—where the coal ash eventually spilled into—and often takes her 4-year-old grandson to the beach. “We don’t know what’s in that water to this day,” she said. “There’s still leaking, it’s still in groundwater, we still have ponds right up against the river.”