Low levels of heavy metals found in the Neuse River, but the water is safe, state says

Coal ash flooded by Hurricane Florence is not contaminating the Neuse River near a Duke Energy power plant in Goldsboro, according to a state laboratory analysis issued Monday evening.

The N.C. Department of Environmental Quality said that the presence of heavy metals in the Neuse River at the H.F. Lee power plant is well below state safety limits for drinking water, although the state data show that metals common in coal ash increase slightly downstream of Duke Energy’s coal ash storage area. The agency tested for a number of heavy metals — such as mercury, selenium and arsenic — that can cause deformities in wildlife and cancer in people after prolonged exposure at elevated levels.

“I would say that there’s not a significant difference between upstream and downstream,” said Jim Gregson, deputy interim director of the Division of Water Resources at the N.C. Department of Environmental Quality. “If there was any coal ash, it was so diluted you weren’t able to discern in it in the samples. That’s typical in flood waters.”

The agency’s test results corroborate lab tests conducted for the past two weeks by Charlotte-based Duke Energy. But they contradict water samples tested by a lab commissioned by environmental activists, who last week warned that arsenic levels in the Neuse River were nearly 18 times higher than safety standards allow for drinking water.

The state agency’s result don’t resolve all concerns. Environmental groups and some independent scientists said it’s still unclear how much coal ash was pushed down the river by the force of the flood.

Duke Energy spokeswoman Paige Sheehan said that very likely very little coal ash escaped its holding pen when the area flooded.

“At the Lee facility, we think about a pick up truck load full of coal ash was displaced from the inactive basins with much of its settling around the foot of the basin,” Sheehan said.

Avner Vengosh, a Duke University professor of geochemistry and water quality who studied lab results after the nation’s biggest coal ash spill, which took place in 2008 in Tennessee, said the state’s report is of limited value because it only provides lab results of the water, which was heavily diluted by flooding, but offers no analysis of the solids found in the water to determine if they came from storm runoff or from coal ash.

Shea Tuberty, a professor of invertebrate physiology and aquatic ecotoxicology at Appalachian State University, said the readings for aluminum, iron and manganese in the state’s lab analysis strongly indicate the presence of coal ash in the river.

“There’s ash in there but it’s very low level,” Tuberty said. He added that the levels are not a concern for drinking water safety because the toxic elements can be filtered out by water treatment plants.

The greater concern is for aquatic wildlife, Tuberty said, because heavy metals can “bio-accumulate” in ecosystems over time, and fish are sensitive to the contaminants at lower levels than humans.

Another scientist, Dean Hesterberg, a professor of soil chemistry in Crop and Soil Sciences at N.C. State University, also said he was not concerned about the low concentrations of elements. But Hesterberg, who analyzed results from the 2014 spill of 39,000 tons of Duke Energy coal ash into the Dan River, suggested more tests would be necessary to determine the long-term impacts of the heavy metals on the ecosystem.

“A challenge of testing for coal ash particles in a river directly is that the coal ash will be intermixed with suspended sediment from other sources like eroded soils.” Hesterberg said.

In North Carolina, Duke Energy started issuing its results last week, based on two downstream water samples in the Neuse River. Duke’s daily lab results, beginning Sept. 18, show that the presence of heavy metals doubled, tripled and even quadrupled over several days, but have stayed well below safe drinking water standards.

The Department of Environmental Quality’s test results came from water samples taken from the Neuse River on Sept. 23, one mile downstream from the coal ash and six miles from the coal ash, after a Duke Energy coal ash impoundment there was flooded by the cresting river in the wake of Hurricane Florence. The basins contain coal ash accumulated from decades of burning coal to generate electricity.

“Test results from the Sept. 23 sampling at H.F. Lee, show all metals at levels below the limits set by state water quality standards,” the Department of Environmental Quality said.

The locations where the samples were taken in the river is the main reason for the difference between the findings of the Upper Neuse Riverkeeper and Waterkeeper Alliance, and the lab results from Charlotte-based Duke and the Department of Environmental Quality. The environmental groups took water samples directly on top of the flooded ash pit, where the concentrations of heavy metals would be the highest.

Duke and DEQ scientists took their samples farther downstream, where the contaminants were diluted.

“It is important to note that DEQ water sampling occurred at multiple locations, which provides a more complete snapshot of conditions as opposed to one sampling location,” the state agency said in its press release. “DEQ is continuing to monitor weekly at the site during the month of October to obtain comprehensive data.”

The agency is also testing the Cape Fear River at Duke’s Sutton power plant in Wilmington, where a coal ash impoundment was flooded. Duke has already issued results indicating that downstream water quality in the Cape Fear River was not harmed by the flooding. DEQ could issue those lab results as soon as Wednesday.

Duke has stored millions of tons of ash in 32 ash ponds at 14 locations across the state. The company is excavating the ash and moving it to lined landfills, in accordance with a 2014 state law and in response to lawsuits filed by environmental activists.

This story was originally published October 1, 2018 at 10:48 PM.