Duke University testing shows Kingston coal ash uranium at triple report levels

The coal ash produced at a Tennessee Valley Authority coal-fired power plant near Knoxville is more than three times richer in uranium – and the dangerous radioactive elements it produces as it breaks down – than documented in public reports after a massive coal ash spill in 2008.

Knox News commissioned Duke University to analyze samples of coal ash the news organization obtained from TVA's Kingston Fossil Plant, the site of the largest coal ash spill in American history.

The Duke University analysis shows TVA’s Kingston coal ash contains more than three times the amount of uranium reported in 2009 by the Tennessee Department of Environment and Conservation and in 2011 in a joint report from TVA and its disaster cleanup contractor Jacobs Engineering.

Duke University employed the industry-standard EPA methods in the tests it conducted in a certified lab in February. Knox News provided Duke University with samples for testing from the 2008 spill, as well as samples taken from the Kingston plant in 2017, 2018 and 2019.

Duke University Professor Avner Vengosh said the test results confirm the radiological threat TVA’s coal ash poses when it becomes airborne.

“If it is dust and you inhale it, it’s a different ballgame,” he explained. “Then, you have radiation in your lungs.”

TVA spokesman Scott Brooks said in a statement the agency has been at the forefront of protecting workers' safety.

"As documented in the 2010 public health assessment and other publicly available information, TVA, TDEC, EPA, and the Tennessee Department of Health worked together transparently to protect public health in the aftermath of the Kingston coal ash release," Brooks wrote.

"TVA’s recovery plan was informed by the best available science on how to perform the work safely. In 2015, EPA awarded TVA its Excellence in Site Reuse award for going above and beyond to support cleanup, ecological restoration, and community revitalization. 

Since the spill, TVA has been converting from storing coal ash in a liquid slurry to a dry form of the toxic byproduct of burning coal to produce electricity. TVA says dry storage is safer for people and the environment. TDEC has similarly touted dry storage as the best means of protecting the public from the threat of coal ash exposure and contamination.

Hundreds of disaster relief workers who cleaned up TVA’s Kingston spill allege they were poisoned by exposure to coal ash dust without adequate protection. A Knox News ongoing tally from public records shows 48 cleanup workers have died from ailments they claim are linked to their exposure.

Knox News tests TVA's coal ash claims

Knox News has been investigating for more than two years TVA’s handling of the spill, Jacobs’ cleanup work and its treatment of disaster relief workers, and the toxicity of the Kingston coal ash.

That ongoing probe has shown TDEC slashed uranium readings by 98% and deleted a reading for one of its most dangerous decay products — radium — in its final public report on the state lab’s analysis of Kingston coal ash published in 2009.

TDEC did not inform the public of those changes. The Tennessee Department of Health later relied in part on those altered results to conclude TVA’s Kingston coal ash did not pose a radiological threat to the public.

TDEC contends the lowered uranium readings — not the ones the agency scrubbed from the public record — are accurate. TDEC's final public report on testing of pure coal ash taken from TVA’s Kingston dump after the spill says it contained 4.61 milligrams per kilogram of uranium, although the agency did not provide a lab report as proof.

In a 2011 report co-authored by TVA and Jacobs, the utility reported the uranium content of the Kingston toxic coal ash waste averaged 5.4 milligrams per kilogram.

"As an initial matter, there was comprehensive testing of water, soil, and air at the Kingston Site in the immediate aftermath of the spill by a number of government agencies and companies, including the TVA, the Tennessee Department of Environment and Conservation, and the EPA," Jacobs attorney Theodore Boutrous Jr. wrote in a statement to Knox News.

"That testing – which was required by the EPA and TDEC – included testing for radiation. TVA, Jacobs, and others relied upon that testing in developing the Sitewide Safety and Health Plan that governed safety protocols during the cleanup and set permissible exposure limits for air exposure to fly ash."

The Duke analysis of Kingston ash provided by Knox News shows an average uranium content of 15 milligrams per kilogram. The uranium content in the Knox News samples ranged from 11.9 milligrams per kilogram to 17.3 milligrams per kilogram.

Vengosh said the uranium content found in the Knox News sample is consistent with the scientific standard now established for coal ash.

“That means your samples are consistent with what we see in hundreds of other tests on coal ash, the scientific standard for coal ash,” he said.

As it decays, uranium produces more dangerous forms of radioactive heavy metals, including radium 226. TDEC insists the state lab couldn’t detect any radium in its analysis of Kingston coal ash aside from the reading it deleted from the final public report. That reading exceeded federal pollution control standards.

TVA and Jacobs are being sued in both federal and state court for allegedly covering up the health threat its coal ash poses.

The ongoing Knox News investigation has revealed TVA has known since at least 1981 that its coal ash contained radium 226 at levels that could cause cancer but never revealed the threat to the public, purchasers of coal ash and coal ash workers. TVA instead has insisted its coal ash is no more dangerous than dirt.

Boutrous accused Knox News of parroting arguments made by attorneys who are representing Kingston coal ash disaster workers who are suing the firm.

"No entity on the site (and certainly not Jacobs) would have or did rely on testing results that were almost three decades old," he said. "Jacobs, EPA, TVA and others relied on the testing conducted immediately after the spill (and throughout the cleanup) to determine what was in the ash and whether the ash presented any type of health risk – at the time of the spill and cleanup."

Vengosh's research on coal ash has now spanned more than a decade. He and his fellow Duke University researchers were the first to raise a radiological alarm about the threat TVA's Kingston coal ash posed if it became airborne.

He is a leading figure in North Carolina's fight to force Duke Energy to dig up its coal ash waste dumps and clean up the contamination left behind. Earlier this year, Duke Energy struck a deal with North Carolina regulators to do just that.

Email Jamie Satterfield at jamie.satterfield@knoxnews.com and follow her on Twitter @jamiescoop. If you enjoy Jamie's coverage, support strong local journalism by subscribing for full access to all our content on every platform.