Mooresville is home to more coal ash structural fill sites than anywhere in the state – and also some of the state’s highest recorded cases of thyroid cancer.
The numbers have many people wondering if there’s a correlation – or if it’s just coincidence.
Public health officials say it’s difficult – if possible – for studies to pinpoint a specific environmental cause for cancer.
Coal ash is a relative newcomer to the environmental debate stage in North Carolina. The byproduct of burning coal, it contains radioactive elements and toxins like arsenic, lead and mercury.
Duke Energy chemists maintain coal ash is largely safe. But a Duke University chemist vehemently disagrees.
If even chemists clash over the safety of coal ash on human health, do we know enough about it to permanently cap 16.8 million tons of it in an unlined basin upstream from thousands of Mooresville residents’ drinking-water resources?
Cap-in-place vs. excavate
The N.C. Department of Environmental Quality will soon decide how Duke Energy should clean and close its 394-acre coal ash basin at Marshall Steam Station, which burns coal for energy.
State law requires the energy company to close all its coal ash basins by Dec. 31, 2029. The law was passed after the company, in 2014, accidentally spilled 39,000 tons of coal ash into the Dan River in Eden.
Duke Energy is excavating coal ash from some basins, but it prefers a more controversial clean-up method – “cap in place” – for Marshall. Water would be drained from the basin, and it would be covered by a protective cap. The ash would be left indefinitely.
Spokeswoman Erin Culbert said Duke Energy’s recommendation for cap-in-place is based on “site-specific engineering, scientific studies and groundwater modeling.”
The company submitted its studies to NC DEQ ahead of a final meeting the state will hold for public comment on how Duke Energy should close the basin. That meeting is scheduled for Thursday, Jan. 17, at Sherrills Ford Elementary School.
Environmentalists like the Catawba Riverkeeper Foundation are encouraging a strong community turnout at the meeting. The groups oppose cap-in-place, saying it isn’t a cleanup method at all. With no liner in the Marshall basin – and therefore no barrier between the coal ash and the ground – they fear a future breach or leak into the groundwater.
Catawba Riverkeeper Brandon Jones said capping-in-place meets federal coal ash storage rules, which require ash to be stored at least 5 feet above the water table. However, he said, “Simply putting a cap on millions of tons of coal ash and hoping for the best isn’t getting rid of the problem.”
Added Emilee Syrewicze, executive director of CRF: “We believe the risk of impoundment failure, combined with the water contamination Duke Energy has reported consistently to authorities, make coal ash one of the largest environmental problems in our region.”
Culbert notes that the dam will remain safe through the process by gradually removing the freestanding water in any closure method and because the dam will be lowered or removed to no longer hold water.
Duke Energy recently reported above-acceptable levels of arsenic, beryllium, cobalt, lithium, thallium and Radium 226 and 228 in groundwater – not drinking water – near Marshall’s coal ash basin.
Earlier last year, the company reported levels of radioactivity at Marshall that were 2.5 times the federal drinking-water standard. Thallium levels exceeded federal standards and were 12 times higher than the state groundwater standard, according to the non-profit Waterkeeper Alliance.
Coal-ash sites – and cancer cases – climb
In addition to its basin, Marshall has 7.3 million tons of coal ash in structural fills and 8.3 million tons in three landfills, one of which is unlined. It was built before regulations required liners, Culbert said.
About 1.24 million tons of coal ash also lies along N.C. 150 in Mooresville. From 1995 to 2001, it was hauled from Marshall to be used as structural fill for commercial development.
During that same time – 1995 to 1999 – the town’s two zip codes, 28117 and 28115, reported 21 cases of thyroid cancer to the N.C. Central Cancer Registry. But from 2012 to 2016, that number jumped to 181 – sometimes up to three times the state average.
The state hasn’t released totals from 2017 or 2018.
A Wind storm brewing
It’s anyone’s guess right now if coal ash could be contributing to Mooresville’s cancer cases.
Culbert stressed that there’s no scientific evidence linking Duke’s operation to the cancer cases.
After her teen daughter was diagnosed with thyroid cancer in 2016, Mooresville resident Susan Wind commissioned a team of Duke University chemists to study the environment around Lake Norman. The team has offered to analyze the past 10 years’ cancer rates – not just thyroid – in both Mooresville zip codes.
“This information will be invaluable since neither the state nor county analyze cancer rates down to zip codes,” said Wind.
She said she has received far too many calls from cancer victims to believe that Mooresville is plagued by only a thyroid cancer problem. “There are other cancers, all on the same streets, in the same small geographic areas and in the same communities,” she said.
“Something isn’t adding up. Something is making these people sick, and everything should be ruled out, including coal ash.”
‘Duking’ it out
Citing the U.S. Geological Survey, Environmental Protection Agency and Electric Power Research Institute, Culbert said trace elements and radioactivity in coal ash are not cause for alarm.
“While coal ash contains trace elements – much like soil, rocks and household garbage do – the levels of these elements in coal ash are not high enough to be considered ‘toxic’ by scientific standards,” she said. “Toxicity depends on dose and exposure, meaning whether an individual is actually getting that substance into his or her body in high enough quantities to cause a negative response.”
She explained it by using a bottle of aspirin: “In a bottle on my desk is fine, taking two for a headache is fine and taking an entire bottle can cause injury.”
Coal ash history
Marshall Steam Station was built in 1965, and its coal ash basin and one landfill are unlined. Culbert said Marshall has always had the technology needed to remove fly ash from the air. Coal ash has also been used as fill in Mooresville since the 1990s.
But Culbert said Mooresville residents shouldn’t worry about the coal ash around town and the lake. “Having a substance near you is not the same as being exposed to it in the toxicological sense,” she said. “True exposure means that there is a pathway for the substance to get into your body. And then an individual would have to absorb enough of a substance to cause a negative response.”
Avner Vengosh, professor of geochemistry and water quality at Duke University and a leading expert on coal ash, explained that people can be exposed to coal ash contamination through water, air and soil. The toxins can seep through soil into groundwater and wells, and the small particles in dry ash can easily become airborne, creating a pathway of exposure to people downwind.
Culbert said the ash-fill projects in Mooresville “were conducted through state permits and regulations that set out how ash could be used in ways that were safe for the community and environment.”
She said the projects covered the ash with soil, preventing ash from becoming airborne as dust. “In many cases, these projects now have commercial development on them that would further minimize opportunities for erosion and would help protect groundwater below,” she said.
Duke Energy made property owners responsible for repairing erosion or other future maintenance needs, she said.
Even if an individual is exposed to coal ash at an incidental level, Culbert said, “the scientific studies tell us that individual would be ingesting an amount similar to or less than what you’d get through your normal diet and water supply.”
But Vengosh said without further study and test results, it’s premature to draw conclusions for Mooresville. “I don’t have a real answer right now, and I don’t like to speculate,” he said. “That’s the way science should be.”
He said scientists are carefully testing Mooresville’s possible pathways of coal ash exposure. “We are finding coal ash in different areas than we expected when we started the study,” he said. “We do see the cancer cluster in your area, and now we see that coal ash is much more frequent than we thought it was.”
But Culbert said Duke Energy has taken appropriate steps to prevent dust and manage ash in approved facilities to “help protect the community from coming into contact with the elements in coal ash.”
Back to the basics
Perhaps the most basic of all questions, though, is: why the need to protect a community from elements in coal ash – and why all the state and federal regulations – if coal ash, in general, is safe?
“Because it’s not safe,” said Vengosh.
He pointed to the largest coal ash spill in United States history: the December 2008 spill of 7.3 million tons of ash from the Tennessee Valley Authority (TVA) Kingston Fossil Plant into the Emory River in Kingston, Tennessee.
As of last month, according to the Knoxville News Sentinel, more than 30 of the 900 workers employed during the seven-year spill clean-up are now dead. More than 250 are chronically ill or dying.
“Those workers were told that coal ash has no human health risk; it’s benign,” Vengosh said. “The (clean-up contractor) used similar language as Duke Energy. They said you could eat coal ash for breakfast.”
The workers are suing Jacobs Engineering, hired by TVA to lead the cleanup efforts, accusing the company of lying to the workers about the dangers of coal ash and failing to provide them with protective gear.
“The judge and jury admitted that it was the responsibility of the company to protect the worker,” Vengosh said. In doing so, the jury also concluded that the workers’ exposure to coal ash could be what caused their illnesses.
“The reason is a no-brainer,” said Vengosh. “Coal ash contains a lot of metals that we know are toxic to human health – at much higher levels than in normal soil. That is a fact.”
When asked why chemists disagree on the safety of coal ash, Duke Energy’s Culbert said: “Our perspective is that coal ash is a well understood material that can be safely managed.”
Vengosh said the difference between him and chemists who work for the energy utility: he works with independent research while Duke Energy’s chemists work for a company.
“We have to overcome strong and serious review from peers and overcome scrutiny to make sure our data is strong,” he said. Conversely, what Duke Energy chemists say about coal ash is “their opinion – not peer-reviewed. It should not be taken seriously.”
Correction: An earlier version of this story stated that the Marshall Steam Station added a scrubber to remove coal ash in 2007, allowing fly ash to escape into their prior to that. According to a Duke spokesperson, that plant actually had a system to capture coal ash for the basin when it was built. The added scrubber additionally removes sulfur dioxide from the air.