DURHAM, N.C. – Avner Vengosh, professor of geochemistry and water quality at 91’s Nicholas School of the Environment, will present expert testimony on the impacts of coal ash on water quality at a public hearing hosted by the U.S. Environmental Protection Agency (EPA), Tuesday, Sept. 14, at the Holiday Inn Airport in Charlotte.

Vengosh will present his testimony at 2:30 p.m.

He will discuss findings of a preliminary investigation of the impacts of coal combustion residuals (CCR) on water quality in Hyco Lake, N.C., as well as findings from his peer-reviewed study of the downstream impacts on water quality following the massive December 2008 spill at a Tennessee Valley Authority coal ash holding pond in Kingston, Tenn.

“Our preliminary study of water quality in Hyco Lake, which receives about 1000 million gallons of CCR a day, reveals boron levels higher than 1000 parts per billion in the lake water,” Vengosh says. “This indicates a significant impact on the lake water quality.”

The lake, located in Person and Caswell counties, was constructed in the early 1960s by Carolina Power and Light Company, now Progress Energy, as a cooling reservoir for its steam electric generating plant.

Vengosh’s ongoing study of environmental impacts from the Dec. 2008 TVA coal ash spill has revealed elevated levels of contaminants associated with CCR, including arsenic, selenium, boron, strontium and barium, in downstream water and river sediment samples.

The levels of the contaminants in surface water samples are below the EPA maximum contaminant level guidelines for safe drinking water, he notes, however, higher levels were found in samples from pore water, which is water trapped within river sediment. “Our research has shown particularly high concentrations of arsenic – up to 2000 parts per billion – and other contaminants in pore water extracted from downstream river sediments,” Vengosh says. “These arsenic levels exceed both the maximum contaminant level of 10 parts per billion for drinking water, and the criterion continuous concentration level of 150 parts per billion for aquatic life.”

The Sept. 14 hearing is scheduled to run from 10 a.m. until midnight.  It is one of seven hosted by the EPA to gain public input on the agency’s proposal to regulate the disposal and management of coal ash from coal-fired power plants.

Nicholas School PhD student Laura Ruhl and Helen Hsu-Kim, assistant professor of environmental engineering, are working with Vengosh on the Hyco Lake and TVA studies.

Note: Avner Vengosh can be contacted for additional comment at (919) 681-8050 orvengosh@duke.edu.