A new Duke University study has found high levels of selenium in fish at two lakes near Duke Energy coal-ash sites in North Carolina. But Duke Energy says its own studies have found no problems with fish from the lakes.
The study published in the journal Environmental Science & Technology found elevated selenium levels in fish from lakes near the Sutton plant in Wilmington and the Mayo plant in Roxboro.
Selenium at a third lake - Mountain Island near Charlotte - was within the federal EPA standard.
Selenium occurs naturally and can be concentrated in coal ash, the residue left from burning coal. It can cause deformities, growth problems and even death in fish and other animals. This study didn't evaluate health risks to humans.
The Duke scientists measured selenium in surface water, bottom-sediment waters and fish in the three lakes, which all have received discharges from coal-ash storage basins near Duke power plants. Three similar lakes that have not had coal-ash runoff also were tested during the three-month study in 2015 - Adger, Tillery and Waccamaw.
“Catastrophic releases of coal ash like the Dan River spill of 2014 get all of the attention, but there is ongoing, continuous contamination of aquatic ecosystems from hundreds of coal ash ponds across the country,” said the study's leader, Jessica Brandt, a doctoral student in environmental health at Duke. “People fish in these lakes for recreation and subsistence purposes. We want to protect these public resources.”
Duke Energy spokeswoman Erin Culbert said the company hasn't seen the study, but said fish populations are thriving in the three lakes.
"These three reservoirs were created to receive wastewater from power plants, and we diligently meet permit limits that were designed to protect the environment through the decades these industrial facilities operated to serve customers," Culbert said.
Both the Sutton plant in Wilmington and Riverbend in Mount Holly, near Mountain Island Lake, have been retired and Duke Energy is cleaning up coal ash basins near the old plants. The Roxboro plant is still operating, but Duke has announced plans to close the coal ash basin there as well.
Sutton Lake had the highest selenium levels, with 85 percent of all fish muscle samples tested showing selenium levels above the EPA’s threshold.
Culbert said Duke Energy's own biologists have never found health effects in fish near the Sutton plant, and game fish in Sutton Lake remain safe to eat.
Feb. 7, 2017, Duke.edu, "High selenium levels found in fish in N.C. lakes receiving coal ash waste."