As Enforcement Lags, Toxic Coal Ash Keeps Polluting U.S. Water

The James M. Barry Electric Generating Plant and coal ash pond in Mobile County, Alabama. Courtesy of Mobile Baykeeper

Despite rules requiring remediation, only a few of the nearly 300 U.S. power plants storing toxic ash — the residue of burning coal — have started cleanups or have plans to do so. Many of these sites are polluting groundwater, threatening the drinking water for millions.

By Austyn Gaffney • March 23, 2023

A few months ago, the New Castle Generating Station, an hour northwest of Pittsburgh, was named one of the most contaminated coal-fired power plant sites in the country. Polluted with arsenic and other toxic chemicals, the facility sits between the village of West Pittsburgh, population 821, and the Beaver River, a tributary of the Ohio River, which serves as a drinking water source for more than 5 million people.

Although the plant, owned by GenOn, largely replaced coal with natural gas in 2016, the site still retains 3 million tons of ash, a mixture of feather-light dust and rock-laden material left over from burning coal. Over the last century, U.S. coal-powered electricity generation has produced at least 5 billion tons of coal ash, enough waste to fill a line of rail cars reaching the moon.

Nearly 60 percent of U.S. annual coal ash production was recycled in 2021, mostly for cement and concrete, according to the American Coal Ash Association. But massive amounts still fill at least 746 coal ash impoundments in 43 states nationwide, with waste sites mostly occurring in rural, low-income areas and often in communities of color. A recent report reveals that, despite federal rules enacted to remediate these sites, very few of the nation's almost 300 coal plants have done so. Nor do they have any plans to.

Coal ash contains at least 17 toxic heavy metals and pollutants including lead, mercury, cadmium, chromium, and selenium, all of which can endanger human health, and at least six neurotoxins and five known or suspected carcinogens. Research shows that prolonged exposure to coal ash via air or water can affect every major organ system in the human body, causing birth defects, heart and lung disease, and a variety of cancers. Coal ash pollution has also caused fish kills and deformities in aquatic life.

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According to Avner Vengosh, a professor of environmental quality at Duke University, toxic metals "are relatively easily leached out [of coal ash], unlike normal soil." Rain that falls on unlined coal-ash impoundments — either ponds for storing wet ash or landfills for storing dry ash — can transport those contaminants to underlying groundwater, he notes, where it can affect drinking water supplies. According to a 2022 Earthjustice report, at least 24 coal ash sites nationwide are known to have contaminated more than 100 private wells.

Groundwater sampling performed at the New Castle plant between 2015 and 2017 showed arsenic levels 372 times higher, on average, than EPA health standards and lithium levels 54 times higher than the proposed federal standard. Earthjustice and the Environmental Integrity Project (EIP) have ranked New Castle the sixth-most contaminated coal ash site in the country.

An aerial view of the New Castle Generating Station in western Pennsylvania. Yale Environment 360

"Even though [GenOn] is leaking toxic pollutants into the Beaver River and local groundwater all the time," said Abel Russ, an attorney with EIP and a coauthor of the 2022 report, "New Castle might not be a priority [for state and federal regulators] because it's remote and, frankly, not a lot of people are complaining about it."

"They keep us in the dark," said Cindy Mozzocio, 66, who has, with her husband, owned a restaurant in West Pittsburgh for 18 years. She remembers that when GenOn cleaned up one of its three waste pits five years earlier, she assumed the site was no longer contaminated. "If they said it's okay, you believe them," Mozzocio said. "You trust your officials."

One of the nation's largest waste streams, coal ash was not regulated by the federal government until disaster struck. Three days before Christmas in 2008, a coal ash pond in Roane County, Tennessee burst open, releasing 1.1 billion gallons of slurry. The waste buried 300 acres, resulting in millions of dollars in damage and allegations — currently under litigation — that failure to prioritize safety during the six-year cleanup contributed to a range of cancers and respiratory illnesses among cleanup workers.

Kingston — the largest industrial spill in U.S. history — finally forced the Environmental Protection Agency, which had been waffling over how to regulate coal ash waste for 30 years, to act. In 2010, the EPA proposed two regulatory pathways. Coal ash could be listed as a hazardous waste, forcing utilities to close their existing coal-ash impoundments and truck the ash to the handful of landfills permitted to handle this waste. Or ash could be listed as a solid waste, which would require all unlined pits to be retrofitted with liners or closed within five years.

The agency settled on the latter route, which was less expensive for utilities, but the Coal Ash Rule, enacted in 2015, seems to have had little impact. Today, 94 percent of regulated U.S. coal ash ponds are still unlined, and two thirds are either sitting in, or within 5 feet of, groundwater, according to industry data compiled and analyzed by Earthjustice.

Coal ash sites at more than 90 percent of the 292 power plants in the U.S. that fall under the rule and have reported groundwater data are leaking contaminants into groundwater, often at levels threatening ecosystems and drinking water. Of these contaminated plants, nearly half have either not committed to a cleanup plan or have denied culpability in the contamination. Only 4 percent of the utilities controlling these sites have selected cleanup plans to treat some of the contaminated water.

The aftermath of the 2008 coal ash spill at the Kingston Fossil Plant in Roane County, Tennessee. Wade Payne / AP Photo

Part of the problem is interpretation of the 2015 rule. Between 1939 and 1978, the New Castle power plant shunted its watered-down waste into a 120-acre unlined pond. By 1984, plant owners claimed this "legacy" pond was de-watered and began layering its waste in a landfill atop that site. The plant also maintained a smaller coal ash pond, to which NRG, the plant's former owner, and GenOn in 2016 applied the new federal coal ash rule: They dried out the pond and dumped its remaining ash in the landfill, which was then covered with dirt. But the companies did nothing to remediate the larger legacy site underneath the landfill, which continued to leak extremely high levels of contaminants into groundwater.

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NRG and GenOn argue that since this legacy pond was dewatered and closed prior to the 2015 rule, the rule doesn't apply to it. EIP's Abel Russ argues it does. Under the definition of "inactive surface impoundments," he says, a site qualifies for regulation if it still contains both coal ash and liquid. According to a report prepared by an outside consultant for both NRG and GenOn, evidence shows the historic impoundment is sitting in groundwater, including a wet coal ash layer at least 9 feet thick submerged beneath the water table. In 2021, the EPA specified in a letter to Duke Energy, which was contesting regulation of a dewatered impoundment in Indiana, that unlined units sitting in groundwater do, in fact, meet the EPA's definition of an "inactive surface impoundment" and are subject to the rule.

GenOn did not respond to requests for comment. NRG spokesperson Pat Hammond did not answer specific questions about New Castle or other plants it formerly owned or operated jointly with GenOn. She stated that NRG has not been affiliated with these plants since December of 2018, adding "many of the individuals who were associated with these plants are no longer with the company."

If GenOn had stopped producing electricity before the 2015 rule was enacted, the company might have avoided cleanup entirely, due to loopholes that keep almost half of U.S. coal ash sites unregulated. These unregulated sites include at least 170 ponds, in the case of utilities that stopped generating electricity before October 2015, and almost 300 inactive landfills, exempt because they stopped receiving ash after October 17, 2015. Challenges to these loopholes are currently working their way through federal court. Under a looming settlement, Earthjustice is urging the EPA to address both loopholes — ponds and landfills — simultaneously.

Like many federal environmental laws, responsibility for enforcing the Coal Ash Rule, which falls under the Resource Conservation and Recovery Act (RCRA), falls primarily to state agencies. Yet in every state where coal is burned, according to the report by Earthjustice and EIP, utilities are violating federal regulations for proper cleanup and disposal.

Frank Holleman, a senior attorney at the Southern Environmental Law Center (SELC), contends the relationship between state agencies and utilities creates a practical problem: State agencies don't want to enforce the law. "No state agency has filed an enforcement action anywhere, against any utility, under the 2015 rule, even though we’ve seen widespread failure to comply," he says.

Part of the problem is capacity. According to Russ, Pennsylvania's Department of Environmental Protection — which has oversight of 21 individual coal ash impoundments at nine active and retired coal plants — is so understaffed and underfunded that enforcement of the highly technical and complicated rule is difficult.

But states may fail to act, also, due to powerful lobbying. "You have industry capture in states that rely heavily on coal to make electricity," says Michael Gerrard, professor of environmental law at Columbia Law School, noting West Virginia, Ohio, and Texas as examples. "Those industries have captured environmental and utility regulators."

At the federal level, Gerrard notes, the Trump administration took office less than a year after adoption of the coal ash rule and "enforcement of all kinds of environmental laws dropped off."

Last year, the EPA finally announced decisions that showed it would start, however slowly, enforcing the law. In January of 2022, the agency denied three coal plant requests to continue disposing of coal ash waste, with six more denials so far this year.

Until rule enforcement picks up, however, communities are left with the Sisyphean task of holding industry accountable by filing lawsuits under the federal Clean Water Act or state environmental laws. According to Lisa Hallowell, a senior attorney for EIP, such actions are "a very time-consuming and resource-intensive process that usually only works with a potential result at a single plant."

Still, the 2015 rule adds a new option for citizen enforcement, and two such lawsuits are currently underway. Last fall, the Mobile Baykeeper filed a citizen enforcement action against Alabama Power, alleging that the utility plans to illegally leave more than 21 million tons of coal ash from the James M. Barry Generating Plant in its unlined impoundment, which lies within the Mobile River floodplain and within five feet of groundwater that is already contaminated with coal-ash pollutants like arsenic, boron, and cobalt. The lawsuit alleges that floods and storms, increasing in the Southeast with climate change, could raise groundwater levels and further saturate the ash.

The other citizen enforcement action comes from Neighbors Opposing Pit Expansion, a group of roughly 100 residents in the Cincinnati, Ohio area. The group alleges that the new owners of a defunct Duke Energy plant that operated for six decades, accumulating more than 6 million cubic yards of waste, are continuing to dump ash in unlined pits, violating the 2015 rule and endangering public utility wells for 130,000 people, in addition to groundwater in the Ohio River floodplain.

"We really need the EPA to enforce the law and make it clear they’re going to stand by what the law's plain language requires, and bring these utilities along with them," said Holleman. "It's unrealistic to expect small nonprofit community groups around the country, and communities around the site, many of whom are lower-income communities of color, will be able to fight huge, multi-billion-dollar monopolies."

Coal ash waste from the shuttered Vermilion Power Station seeps into the Middle Fork of the Vermilion River near Collison, Illinois in 2018. Zbigniew Bzdak / Chicago Tribune / Tribune News Service via Getty Images

Instead of remediating coal ash sites on a case-by-case basis with expensive litigation, coal ash should be recategorized as a hazardous material under RCRA, said the EIP's Hallowell. Defining coal ash as hazardous would avoid the current loopholes and subject it to tighter landfill regulations and a stricter set of worker safety requirements.

John Ward, communications coordinator of the American Coal Ash Association, a trade group focused on recycling coal ash, said regulating this material as hazardous would be "untenable" for the industry and would kill the coal ash recycling industry. "It's a lot better to put this stuff in concrete and building products where it's locked up, than piling millions of tons in a landfill somewhere," he said.

Today, more than 99 percent of existing U.S. coal plants are more expensive to run than replacements that rely on wind, solar, and battery storage. Utilities are either shutting down coal plants or retrofitting them to burn natural gas. GenOn, for example, has converted all 22 of its plants to natural gas or oil.

But as the power grid transitions, hundreds of millions of tons of coal ash have been left behind. According to EPA data, the 299 coal-burning plants that remain in the U.S. continue to generate almost 70 million tons of new ash a year. The contaminants from this waste continue to migrate into drinking water sources and lakes and rivers used for recreation.

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"Everybody has been focused on the danger of storing [coal ash] in impoundments," says Vengosh, who discovered that pollution was migrating broadly from 30 North Carolina coal ash impoundments into five lakes less than a mile and a half away. "We showed that the train has already left the station. The coal ash is already in the environment."

Austyn Gaffney is a Kentucky-based writer who covers energy, climate change, and culture, largely in the South. Her work has appeared in The Guardian, National Geographic, The New York Times, Rolling Stone, and The Washington Post, among others. More about Austyn Gaffney →

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