The Ronald Reagan Building, home to the EPA.
The Ronald Reagan Building, home to the EPA, was built with coal ash. Credit: wallyg / Creative Commons

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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.


The amount of coal ash in the United States is hard to fathom. There are over 700 impoundments holding more than 2 billion cubic yards of ash — enough to cover the entire state of Pennsylvania one-half inch deep. 

Coal ash includes heavy metals like chromium, arsenic and selenium — linked to higher rates of cancer and other diseases — that can leach into groundwater. 

Environmental Protection Agency rules adopted in response to a catastrophic ash spill in Kingston, Tennessee, require companies to follow strict disposal procedures or divert ash to beneficial use. This process recycles ash as building material or structural fill. Coal ash can replace cement as a key ingredient in concrete, and it can be used to build roads and foundations.

Reusing ash in this way, known as “beneficial reuse,” is regarded by many environmentalists, regulators and industry sources as preferable to storage in landfills. Currently, about three-fifths of coal ash produced each year is reused, and there are efforts underway to dry out and reuse some of the ash currently sitting in landfills, though significant cost and technical barriers remain and companies are often resistant to this option.

“The best solution to disposal problems is to quit throwing it away,” said John Ward, chair of Citizens for Recycling First and executive director of the National Coal Transportation Association.

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

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

Lead

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

Lithium

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

Arsenic

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

Molybdenum

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

Cobalt

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? 
Companies

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. 

Ratepayers

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. 

Government

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.

Industry experts and regulators alike say it is better to use the byproduct than store it. Environmentalists generally support use as a way to keep coal ash out of leaking ponds, but say more oversight and regulation are needed to make sure that reuse isn’t exposing people to toxic metals. Proponents note that there are no examples of coal ash reuse causing harm since the federal coal ash rules were adopted in 2015.

The EPA and many state agencies encourage — or require — coal ash reuse. The 2015 federal rules detail four criteria for beneficial use. However, the fourth — a maximum volume requirement before further scrutiny is enforced — was based on internal reporting errors.

Advocates say this loophole makes it impossible to know where ash is used in many cases, much less whether it is safe. Industry groups, meanwhile, say the cap triggering scrutiny is arbitrary and should be much higher.

The EPA offered to revise the coal ash reuse regulations to avoid reprimand from a federal judge. It has now been seven years since the regulations first took effect, and four since the EPA announced it would revise the beneficial reuse component.

The EPA’s only concrete proposal to change the rule was uniformly rejected by industry experts, environmentalists, states and academics alike. In January, the EPA announced a renewed effort to regulate coal ash, and while it did not specifically mention beneficial use, challenges to the rule are on the horizon.

Ultimately, stakeholders worry that if regulations around beneficial use are too strict, more coal ash may end up in landfills or ponds where it can pollute groundwater. If regulations are too weak, beneficial use could cause unknown contamination.

How does ‘beneficial use’ work?

Structures containing coal ash are all around us, including the building housing the EPA’s headquarters in Washington, D.C., and the world’s highest concrete arch bridge, soaring over the Colorado River. Coal ash is also widely used for building up land; the Milwaukee Art Museum juts out onto Lake Michigan on ground built with coal ash. 

In 2020, America reused 40 million tons of coal combustion residuals — the term for different types of coal ash as well as other byproducts of burning coal. These residuals — of which ash makes up two-thirds — are found in a plethora of products including concrete, drywall, agricultural fertilizer, structural foundation materials, and roadways. 

Coal ash is most commonly used as an ingredient in concrete, reducing the need for cement. Fly Ash C, loose fluffy ash that flies up stacks, can dramatically increase the concrete’s strength.

“You can’t design bridges and roadways to last 100 years without it,” Ward said.

Cement is also very carbon-intensive to produce, which means using fly ash in concrete not only prevents the toxic material from potentially harming communities, it also helps reduce emissions.

Another byproduct of burning coal is synthetic gypsum, a material created by the chemical reactions while filtering air released from coal plant smokestacks. Gypsum can be used as a key component of drywall.

In both drywall and concrete production — which make up the vast majority of reuse — the coal combustion residuals are chemically bound such that the toxic chemicals are unlikely to escape. The EPA calls this encapsulated use.

But the EPA rules also allow so-called unencapsulated use, including fertilizers, roadways, mine fills and foundation supports. Advocates say these uses could pose a risk to groundwater. 

In the construction of roads, for example, coal ash is piled up to level areas for asphalt to be laid on top. According to Richard Kinch, former chief of the EPA’s Industrial Materials Reuse Branch and key regulator during the creation of the 2015 rule, this process is environmentally safe because the ash is dispersed over a massive surface area, and covered such that water does not run through and carry toxins into groundwater. He said even roadways near large surface water bodies are safe because the quantity of ash that could reach the water is low. 

For non-roadway projects, there is only federal oversight of unencapsulated projects greater than 12,400 tons — enough to fill about 900 dump trucks. Therefore, for any project under that weight, the company is only required to state that projects are environmentally safe in internal documents not easily available to the public and not necessarily subject to public records laws, depending on the state. 

For environmentalists, this process poses two frustrations. First, if the documents are not available, watchdog groups cannot know where exactly unencapsulated projects have occurred. The lack of data means they cannot proactively test water quality at use sites. Since most private wells, where almost a sixth of people living in the United States get their water, are not subject to routine testing, drinking water contamination could go undetected. 

Second, it’s up to companies themselves to determine whether their coal ash use meets the federal criteria. 

Jenny Cassel, a senior attorney at Earthjustice, said that while large quantities are likely more problematic, she also looks to location-based risk factors. “Is it above the groundwater table? Is it in an unstable area? Are there sinkholes? Is it in a wetland? Is it in a floodplain? Is it in a seismic area? All of those kinds of considerations also have a big effect on whether it’s a concern and how much of it is going to pose a problem.”

How do the regulations work?

The 2008 Kingston spill unleashed more than a billion gallons of coal ash slurry containing arsenic, lead and other toxins when a dike on an impoundment failed. The toxins are blamed for the subsequent deaths of more than 30 cleanup workers, who were not provided adequate protective gear.

During years of contentious debate leading up to the 2015 federal rules on coal ash, advocates sought to have coal ash declared a hazardous waste, so that stricter regulations would be placed around its disposal. But industry players who relied on beneficial use argued the designation would make it nearly impossible for them to keep incorporating it into building products and roads, paralyzing whole sectors.

Eventually the rules were adopted without a hazardous waste classification. This decision meant industries that reuse coal ash were protected, and it left much of the regulation of beneficial reuse to the states, whose policies vary significantly.

Wisconsin requires notification of use over 5,000 cubic yards. California requires 25% of cement to be replaced with fly ash. Hawaii has no additional regulations. 

Pennsylvania allows coal ash to be used in filling old coal mines, so that it soaks up acid drainage and prevents it from causing pollution. 

The federal government, however, specified four criteria that must be followed in beneficial use. The ash must provide a functional benefit, substitute for a virgin material, meet design standards and, in unencapsulated, non-roadway uses, be less than 12,400 tons. Any project over that weight would require EPA approval.

Of the four federal requirements for use, the first two have sparked little controversy. The third — a requirement that projects follow industry design standards — could be interpreted in varying ways.

Current industry practice is to follow design and engineering standards developed by ASTM International, a standards organization that develops best practice guidelines for a range of projects. These guidelines reduce the project’s potential to pollute groundwater. Although no use project is guaranteed not to leach chemicals, Tom Adams, executive director of the American Coal Ash Association, said ASTM has designed unencapsulated project standards to ensure environmental safety. 

However, there is no requirement to follow the ASTM guidelines. The regulations state that companies must follow best design practices and Adams considers ASTM the best. Companies could argue other practices, either from in-house or external resources, are better. This means uniformity across projects is not guaranteed.

In 2012, AES Puerto Rico, a utility that provides power to the island, was investigated for its distribution of Agremax, the brand name it gave its coal ash slated for beneficial use. According to an EPA report developed by researchers at Vanderbilt University, the product leached arsenic, boron and chromium — among other chemicals — beyond federal allowances.

Agremax was created before the 2015 coal ash regulations and the current product would not be considered eligible for beneficial use. Even though Agremax is no longer designated for beneficial use, Cassel worries a similar situation could unfold even with the federal mandates in place. 

The fourth criteria — that non-roadway unencapsulated projects greater than 12,400 tons require a demonstration of environmental benefit to the EPA — is where industry and environmentalists disagree most.

Currently, there is no federal requirement for reporting coal ash beneficial use projects under 12,400 tons; companies must internally declare they have followed the four criteria to use the ash. Energy News Network obtained copies of documents for the projects over the threshold submitted to the federal government in the last five years.

Kinch said the 12,400-ton threshold was written as an afterthought, tacked onto the first rule just before publication. 

According to Kinch, In 2015, the EPA thought the smallest monitored landfill in the United States was 12,400 tons. The logic was that any project exceeding the size of an established landfill should get further attention.

However, the EPA made an error. The smallest monitored landfill is actually 74,800 tons. 

“We quickly found out that that data was grossly an error,” Kinch said. “Instead of being honorable about it, which was to make the correction, they didn’t like having to go up higher. I just think that from a good government standpoint, that was wrong.”

In 2018, following a lawsuit from industry and environmentalists, a federal appeals court allowed the EPA to voluntarily revisit its beneficial use regulations. The lawsuit, brought by industry, focused primarily on the fourth criteria, asserting that the 12,400-ton number is “arbitrary.”

This decision led the EPA to release a proposal in 2019 to eliminate the volume restriction and instead require only cases where ash was placed in established risk zones — unstable areas, floodplains or seismic zones — to demonstrate a lack of environmental harm. The proposal was met with vitriol from all sides. Industry, environmentalists, and state governments unanimously rejected the EPA’s suggestions.

“It was one of the more interesting proposals I’ve ever seen from the EPA because everybody hated it,” Ward said. “The beneficial use people hated it, the environmental groups hated it, the state regulators hated it, everybody hated it.” 

Industry claimed notification for all uses would be too burdensome. Some soils — which have proven safe — are available at major home improvement stores and contain coal ash. Under the proposed rule, individual homeowners living in risk zones may theoretically have to file paperwork with the EPA to use these products in their yards. Environmentalists meanwhile claimed the law would allow for major loopholes in coal ash storage: that companies use unlimited quantities of coal ash without EPA approval in non-risk areas.

Tennessee and Virginia both have state coal ash laws on the books that include relatively strong safeguards on coal ash reuse. Regulators in these states argued that their laws would be undermined by putting more requirements on users of coal ash.

Wisconsin, meanwhile, has one of the highest levels of coal ash reuse in the country. That’s thanks to laws that encourage reuse, said Phil Fauble, the director of beneficial use of industrial byproducts at the Wisconsin Department of Natural Resources. When companies have standardized rules, they are more likely to reuse coal ash. Without clear standards, companies might fear lawsuits and be more reluctant to reuse the industrial waste. 

“We tried to make it so that they have some regulatory certainty that if they use these materials they would be fine,” Fauble said. “I think what actually causes utilities and others not to reuse this material is that they don’t have that regulatory certainty.”

In January, the EPA denied eight companies’ requests for extensions for closing their ponds in compliance with the 2015 coal ash rule. Although this action was not related to beneficial reuse, it signals a renewed effort by federal regulators to examine coal ash safety and compliance, according to Earthjustice and other environmental watchdogs.

Should new regulations about beneficial use be announced, the government, environmentalists and industry have differing perspectives on what they would like to see included.

Paul Mathewson, staff scientist for Clean Wisconsin, played a key role in the creation of Wisconsin’s state-level beneficial use regulations. A strength of the state law is its reporting requirements, as he sees it. 

Mathewson said he wants companies to report unencapsulated beneficial use so a database can be compiled and sites can be studied. 

“All we have is the absence of evidence that it is unsafe,” Mathewson said. “But that is very different than evidence that it is safe.”

Growing coal ash demand?

The aptly named “Haulin Ash Avenue” hosts a massive mound of fly ash in Montour County, Pennsylvania.

It is just a fraction of the 150,000 tons removed from a landfill holding coal ash from the Talen Energy Plant, a former coal plant now powered by natural gas. 

This effort, by Eco Material Technologies, is one of many across the country to excavate previously disposed coal ash to be slated for beneficial use. Companies like Eco Material see this as an increasingly attractive option to keep up with ash demand.

From 2010 to 2020, the United States reduced coal-generated power by 58%. This means that the demand for coal ash will soon outpace the new ash supply created from burning coal.

Use has become so common in the concrete industry that Ward has to assure nervous manufacturers the supply of ash will not waver. 

“The first decade of my life in the coal ash industry was talking about the durability and environmental benefits of this practice,” Ward said. “Now I go around the country talking to highway engineers, explaining to them all the things that are in the works to keep them from running out of this material, because they need it.”

Industry pushed the EPA and state agencies to develop plans for excavating coal ash from landfills so it could be reused. “Regulators’ heads exploded because no one had asked to open a landfill before,” Ward said.

A problem with excavating coal ash, however, is it is frequently disposed of in an indiscriminate manner. This means Fly Ash C is mixed with gypsum, bottom ash and even cafeteria waste in landfills. The combination has made finding quality ash, Fly Ash C, like finding needles in a haystack.

According to Rafic Minkara, Eco Material’s vice president of development, Eco Material has developed the sorting technology to excavate and use the ash from certain types of landfills. But the sorting technology is only possible at sites with the right combination of waste. 

Georgia Power and Electric Power Research Institute have also begun the process to excavate coal ash from Georgia Power’s landfill at Plant Bowen, northwest of Atlanta, according to documents submitted to the EPA and obtained by Energy News Network. 

Coal ash is already imported from foreign countries to meet the demands of the construction industry, and imports will likely increase in the future, Ward said. Kinch noted that if utilities were required to separate types of ash in landfills, it could be more easily reused later, and reduce the need for imports.

Researchers are also investigating whether coal ash can be mined for the rare earth minerals that are increasingly needed for batteries and other clean energy technology. There’s even research on whether coal ash can be used to soak up and sequester carbon dioxide to combat global warming, though neither of these options are currently scalable to industrial quantities. 

Adams said he frequently receives requests for funding new coal ash use research. For the relatively young world of ash use, he sees this as a promising sign.  

From 2000 to 2017, 118.4 million tons of coal ash were beneficially used, according to Earthjustice: Enough to cover a six-lane highway from Washington, D.C. to Sydney, Australia. It would have ended up in landfills, but instead went to beneficial use projects across the country.

Questions or comments about this article? Contact us at editor@energynews.us.

Tom Quinn

Tom Quinn graduated from Northwestern with a bachelor's degree in journalism. He spent much of his college sailing career on Lake Michigan as a skipper for the Northwestern Sailing Team. He is now in New York City exploring a passion for law and listening to podcasts while walking along the Hudson River.