Test results show thallium at Cliffside
Recent water tests at the Cliffside Steam Station show traces of thallium coming from discharge areas at the plant.
According to the North Carolina Department of Environment and Natural Resources (DENR), samples from an inactive coal ash basin showed above-average traces of the toxic metal. DENR did report there were no issues stemming from the traces downstream in the Broad River.
The Centers for Disease Control and Prevention (CDC) define thallium as a “bluish-white metal that turns gray on exposure to air.” Additionally, the CDC’s website said thallium has not been produced in the United States since 1984 and had been “used historically as a rodenticide, but has since been banned in the United States due to its toxicity from accidental exposure.”
Susan Massengale, spokesperson for DENR, said the state does not have a water quality standard for thallium and they use the national criteria for water supply tests. She said the national criteria suggests 0.24 parts per million are acceptable levels of the metal.
She said, at the base of inactive coal ash basin No. 5, tests revealed 0.35 parts per billion at the toe drain. However, closer to the Broad River, the tests indicated 0.13 parts per billion of thallium.
DENR said no downstream municipalities have reported any issues meeting the Environmental Protection Agency (EPA) drinking water standards.
“We are talking about an area where the sample had not met the river,” Massengale said. “At that point, we saw those lower levels of thallium.”
The tests come on the heels of a Feb. 2 spill of coal ash into the Dan River near Eden. That spill, from Duke Energy’s station, released nearly 38,000 tons of coal ash into the Dan River, according to DENR.
DENR has conducted inspections of all 33 coal ash impoundments across the state. The tests also indicated levels of thallium at the Asheville Steam Electric Station. DENR said the levels of thallium were below “national recommended water quality criteria for recreational waters in three water samples collected.”
While the tests at the No. 5 coal ash basin revealed thallium, Massengale said two other samples taken from the other four basins showed no indications of thallium present.
Duke Energy spokeswoman Paige Sheehan said Duke will respond to the state’s tests.
“We routinely monitor groundwater around out plants and share results with the state,” Sheehan said in an email.
She said it was important to note the state reported no issues from downstream municipalities from thallium.
The Cliffside Steam Plant has been the subject of monitoring by state officials after a tension pond which contained storm and wastewater overflowed to a secondary pond and into a corrugated pipe that failed, leaking the water into the ground. The Cliffside plant was also cited for issues at two of its “high-hazard” dams. Those issues ranged from improper vegetation on berms to seepage and corrosion in pipes lying at the base of one of the dams.
Duke has also been cited for a lack of mandatory storm water permits. Earlier in March, it was discovered that the Cliffside Steam Station had never applied for a storm water permit. The plant does have a wastewater permit but no storm water regulations are written into the wastewater permits.
Massengale said it was too early to tell if there were any long-standing effects of the thallium detection.
“We are still in the process of gathering information and we still have other information we need to collect,” Massengale said. “We need to get all of our information together before we make a determination but the level doesn’t look like it is affecting the river but I don’t want to draw any conclusions.
“I’m sure our lab is working very diligently to get these results processed as quickly as possible. We went to all 14 facilities and it may take a little bit of time.”