One hundred days after one of the nation’s worst industrial spills, the Tennessee Valley Authority is bringing more medical experts to the spill site in Kingston, Tenn., to evaluate and respond to lingering health concerns.

TVA President Tom Kilgore said Tuesday that Oak Ridge Associated Universities will be employed to help assess the health effects from the Dec. 22 spill. The ash spill at the Kingston Fossil Plant covers nearly 300 acres in Roane County, including a cove of the Emory River.

“We understand this is a difficult time for residents of the Kingston community, and we are working to make things right,” Mr. Kilgore told a congressional panel Tuesday in Washington, D.C.

With more than 100 academic universities in its consortium, the Oak Ridge Associated Universities can help design medical monitoring programs and independently monitor TVA’s cleanup of contaminated sites, Mr. Kilgore said.

Most air and water samples around the Kingston plant in the past three months have shown no significant health risks, EPA and Tennessee Department of Environment and Conservation reports indicate.

But some soil and water samples closest to the ruptured sludge pond taken soon after the spill showed elevated levels of toxic materials, including arsenic, mercury and selenium. That has many residents scared and confused, according to Sarah McCoin, a seventh-generation Harriman, Tenn., resident who belongs to the Tennessee Coal Ash Survivors Network.

“Many people fear that they are poisoning their family by staying where they are,” Ms. McCoin testified Tuesday during a hearing before the House Subcommittee on Water Resources and Environment. “TVA is not listening to us. It’s as if they don’t care.”

Avner Vengosh, a professor of earth and ocean sciences at Duke University who has studied the Kingston ash spill, said part of the Emory River showed arsenic levels more than 100 times greater than what is acceptable in drinking water. Dr. Vengosh said other samples of the river downstream showed elevated levels of mercury.

With such findings, Dr. Vengosh said, he believes the coal ash spilled in Kingston is a hazardous material.

Renee Victoria Hoyos, executive director of the Tennessee Clean Water Network, urged that the spill site be treated as a federal Superfund site. She also said EPA should ban any more wet storage of coal ash.

TVA employs wet-ash disposal at six of its 11 coal plants, including Kingston. The ash is the byproduct of burning coal to produce electricity.

In a separate report released Tuesday, the Environmental Integrity Project said TVA records over the past decade indicate heavy metals have been detected around all six of the TVA coal plants that use wet ash disposal.

“TVA plants are routinely discharging toxic metals at levels that are predicted to damage aquatic ecosystems or make fish unsafe to eat,” said Eric Schaeffer, a former EPA official who now heads the Environmental Integrity Project of Washington, D.C.

Mr. Kilgore said TVA will end its wet ash disposal at the Kingston plant and is conducting a comprehensive study of its other coal ash ponds.

During Tuesday’s hearing, Tennessee Valley congressional representatives urged TVA to clean up the Kingston spill and protect neighbors of the coal plant. But they also cautioned against using the Kingston spill to try to end coal-fired power production, which supplies 60 percent of TVA’s electricity.

“If we do away with coal in this country, you are going to see a doubling, tripling or even quadrupling of electricity prices, and that is going to hurt the poor the most,” said U.S. Rep. John Duncan, R-Tenn. “We just can’t go along with the kooks and the extremists.”