Coal ash found in soil near Trump National, 19 other Lake Norman sites, study reveals
Duke University scientists found potentially toxic fly ash in the soil at 20 sites they tested along the Lake Norman shoreline downwind of Duke Energy’s coal-fired Marshall Steam Station, according to a study by the school’s Nicholas School of the Environment.
The scientists said they detected ash in only low concentrations, well within human health guidelines. But their findings suggested that ash from the power plant was widely distributed by the wind.
The sites where ash was detected included near Trump National Golf Club, Charlotte, the Queens Landing entertainment complex, public boat launches and Mecklenburg County’s Ramsey Creek Beach, according to a map of the locations analyzed by The Charlotte Observer.
The scientists also detected fly ash in soil near Lake Norman High School; at the nearby N.C. 150 bridge near the popular Toucan’s Lakefront restaurant; and, on the western side of the lake, near the Westport community and Beatty’s Ford Park in Lincoln County, according to the Observer analysis.
Scientists found no fly ash at sites north of the plant, according to the study. Marshall Steam Station is on N.C. 150 at the Iredell-Catawba county line.
“The tests consistently showed that most of the samples collected downwind of (Marshall and a Tennessee power plant) contained fly ash contamination,” according to a July 22 Duke University online post announcing that its scientists have developed new tools for detecting tiny amounts of fly ash.
“But because the proportion of the fly ash was low, the concentrations of toxic elements did not exceed human health guidelines for metals occurrence in soil.”
Toxic metals in fly ash
Fly ash, a powdery byproduct of burning coal, contains mercury, cadmium, arsenic and other contaminants, according to the federal Environmental Protection Agency.
“Inhaling dust that contains fly ash particles with high levels of toxic metals has been linked to lung and heart disease, cancer, nervous system disorders and other ill effects,” according to the Duke University post.
The concentrations of fly ash found downwind of the plant were well below state and federal thresholds, according to the university post, which didn’t say what concentration levels of fly ash were found.
The findings, however, show that areas downwind of coal-fired plants should be regularly monitored to protect human health, according to Avner Vengosh, Duke University distinguished professor of environmental quality who co-authored the Lake Norman study.
“Fly ash accumulates over time, and risks can grow with repeat exposures to playground dust or home dust,” Vengosh said in the university post.
The risks of coal ash
“Low concentrations of toxic metals in soil does not equal to no risk,” Vengosh said in the post. “We need to understand how the presence of fly ash in soils near coal plants could affect the health of people who live there.
“Even if coal plants in the United States are shutting down or replaced by natural gas, the environmental legacy of coal ash in these areas will remain for decades to come,” Vengosh said..
Vengosh provided The Charlotte Observer a map with dots where the scientists tested for fly ash, but he declined to provide addresses and names of the locations, citing privacy concerns. The Observer identified locations by matching the dots with an official state map of the lake.
“It’s important to emphasize that our research was not aiming to systematically cover neighborhoods but rather test our method with different independent methods for detecting small levels of fly ash in soil,” Vengosh said in an email.
On Tuesday, Vengosh said he would provide the Observer with the concentration levels of fly ash found by the scientists, but hadn’t replied with the data by Wednesday afternoon.
In a phone interview, Vengosh told the Observer a more comprehensive health study of Lake Norman residents, including health officials going door-to-door, would be needed to link Marshall emissions with any clusters of health ailments in the area.
In 2019, for instance, the Observer reported on a baffling number of thyroid cancers in southern Iredell County, an area where the Duke University scientists detected fly ash.
Some of the state’s top health and environment officials, legislators and scientists from Duke University and UNC Chapel Hill briefed local doctors on a March night that year about ongoing research into the cases, the Observer reported at the time.
The officials named an advisory panel of state and national experts.It was not immediately known Wednesday if the panel still meets or has issued findings.
Iredell, Duke Energy respond
“We just became aware of the release of this report and have not had an opportunity to review it in its entirety,” Megan Redford, health promotion manager and spokeswoman at the Iredell County Health Department, told the Observer in an email.
“We are dedicated to addressing public health concerns that impact the health of Iredell County residents and appreciate the work that was done in Iredell County by Duke University,” she said.
Duke Energy spokesperson Bill Norton said “a large body of evidence” shows “the Lake Norman area remains safe from coal ash impacts, and a preliminary review of this new study reinforces that same conclusion.
“Critically,” Norton said in an email, the study found “low concentrations of hazardous trace metals in the studied soil samples, which in most cases were below the guideline values recommended by the US EPA and other environmental agencies.
“This is in line with what other experts have said before — that concentrations of nearly all trace elements in coal ash are below levels established by the EPA as safe for residential soils.”
Norton said devices called electrostatic precipitators, installed at Marshall in the early 1970s, “remove more than 99% of the ash generated from coal combustion.”
Flue gas scrubbers added in 2006 and 2007 upped that figure to 99.7% or more, he said.
Other coal ash findings
Duke University scientist Heather Stapleton previously sampled in multiple Lake Norman-area homes and found “elevated levels of flame retardant compounds, rather than coal ash,” Norton said. NC Policy Watch reported on Stapleton’s findings.
Experts researching the cases of thyroid cancer, including North Carolina’s health department, found no connection with anything in coal ash, Norton said.
The Observer confirmed that finding in a 2019 state report about thyroid cancer in Iredell County.
“There are no published studies to support an association between coal ash exposure and thyroid cancer,” officials with the N.C. Department of Health and Human Services said in the report.
And soil tests at five Lake Norman-area schools last year likewise found no coal ash, Norton added. The Iredell County Local Thyroid Cancer Workgroup did the tests in partnership with UNC Chapel Hill, Duke University and the N.C. Policy Collaboratory. Their report is on the Iredell County government website.
“Our testing extends well beyond air emissions, and decades of scientific monitoring of Lake Norman and the air around Marshall Steam Station demonstrates that residents are well-protected,” Norton said.
This story was originally published July 29, 2021 at 6:00 AM.