Major utilities have found evidence of groundwater contamination at coal-burning power plants across the U.S. where landfills and man-made ponds have been used for decades as dumping grounds for coal ash, according to data released by plant owners under a Friday deadline.
Heightened levels of pollutants — including arsenic and radium in some cases — were documented at plants in numerous states, from Virginia to Alaska.
The Environmental Protection Agency required the plant owners to install test wells to monitor groundwater pollution as a first step toward cleaning up the sites.
The future of that effort was cast into uncertainty Thursday when the Trump administration announced it intends to roll back aspects of the program to reduce the industry's compliance costs by up to $100 million annually.
"There's no dispute that the underlying groundwater is being contaminated. We see that clearly," said Duke University professor Avner Vengosh, who researches the effects of coal ash and has reviewed some of the new data. "The real question is whether it's migrating toward people or wells next to (coal plants)."
Vengosh added that the discovery at some sites of radium at levels far exceeding drinking water standards — which can increase the risk of cancer — were of particular concern. It appears to mark the first time coal ash has been associated with radioactivity in groundwater, he said.
Duke Energy spokeswoman Erin Culbert noted that government-sponsored research has shown most coal ash does not have radioactive elements. She said the elevated radium levels reported at some Duke plants reflected raw data that had not been analyzed to determine if the contamination was naturally occurring or came from another source.
The Associated Press conducted an initial review of the reports, which were still being filed Friday, and spoke with power company executives across the country, who warned against misinterpreting the pollution data.
Generally, they said further studies were needed to confirm the ash storage sites as the source of the contamination and whether public drinking water supplies were threatened.
U.S. coal plants produce about 100 million tons annually of ash and other waste, much of which ends up in unlined disposal ponds prone to leak. Some have been in use for decades.
Among large U.S. utilities, Duke Energy reported preliminary findings of contamination of groundwater at 48 ash basins and landfills. American Electric Power, or AEP, reported potential groundwater impacts at 24 ash disposal sites. Dominion Energy, the Tennessee Valley Authority, Xcel Energy, and others also reported evidence of contamination.
Mark McCullough, executive vice president at AEP, said the company needed more data to decide which sites will need to close.
"These (monitoring) wells that are close to the sites are telling us something, and we are committed to doing the hard work and to understand where the real source is and what it is," McCullough said.
Pam Faggert, the chief environmental officer for Richmond, Virginia-based Dominion, said the company also conducts surface water tests near its facilities and was confident that the groundwater impacts were not having an effect on public drinking water or public safety offsite.
Coal ash storage and disposal went largely unregulated until a 2008 spill at a Tennessee Valley Authority power plant in Kingston, Tennessee. A containment dike burst and flooding covered more than 300 acres (121 million hectares), dumped waste into two nearby rivers, destroyed homes and brought national attention to the issue.
In 2014, an estimated 39,000 tons of coal ash spewed into the Dan River after a drainage pipe running below a waste dump collapsed at a Duke Energy plant in Eden, North Carolina. The toxic sludge turned the river gray for more than 70 miles (112 kilometers).
Apart from spills, other ash problems have been documented across the country.
On Friday, Alabama regulators proposed $1.5 million in fines for coal ash pollution from six power plants in violation of clean water laws. Five of the plants are owned by Alabama Power, a subsidiary of Southern Company.
In Montana, an estimated 200 million gallons (757 million liters) of contaminated water a year have been leaking into the groundwater from ash ponds in the city of Colstrip, leaving the water undrinkable. And in Virginia, Dominion has offered to hook some neighbors of the Possum Point Power Station up to municipal water after groundwater testing found elevated levels of some contaminants.
Attorney Lisa Evans with the environmental law firm Earthjustice said the pollution reports underscore the need for strong rules on cleaning ash disposal sites, even as the Trump administration appears to be heading in the opposite direction.
"This data shows what communities have been concerned about: Coal ash landfills and impoundments are leaking," Evans said, adding that Thursday's proposal could lead to the "evisceration" of current regulations.
Another environmental attorney, Frank Holleman with the Southern Environmental Law Center, pushed back against the utilities' argument that the data so far has been largely indicative of on-site contamination, not a broader public health threat. He said groundwater doesn't stay in one place — it moves and flows.
Remediation work at some coal ash disposal areas already is underway.
AEP has closed six ash storage sites to date, the company said. Duke Energy has started excavation work at 11 sites and had spent $1.4 billion on such efforts through last December, the company disclosed last week. It plans to spend another $2.5 billion on ash site closures over the next five years.