News that a storage tank at a shuttered federal nuclear facility in Washington state is leaking radioactive sludge has raised fears that the toxic stew could reach the Columbia River as a U.S. cleanup effort drags on.

“The great concern is these tanks have the most dangerous waste of all,” said Brett VandenHeuvel, executive director of Columbia Riverkeeper, an environmental group based in Hood River, Oregon. “They were constantly reassuring us that there is no leaking. This announcement is alarming.”

VandenHeuvel’s group was formed to protect the Columbia, a major transportation artery, salmon habitat and drinking water source that runs alongside the U.S. Energy Department’s Hanford nuclear reservation for about 50 miles and forms much of the border between Washington and Oregon.

The Energy Department announced last week that as much as 300 gallons of radioactive sludge a year was leaking from a storage tank that is more than six decades old.

The leaky tank is one of 177 stored underground that collectively hold about 56 million gallons of waste, enough to fill a football field to a depth of 150 feet, according to the Government Accountability Office. The GAO, Congress’s investigative arm, issued a December report warning of more delays and cost increases in the project to develop a waste reprocessing facility on site.

Seven Miles

The tanks lie as close as seven miles from the river, according to the Oregon Department of Energy. It would take years and even decades for groundwater to reach the river from the area where the tanks are located, the department said.

The U.S. Energy Department has said radiation levels in the soil at Hanford haven’t gone up since a decline in liquid levels within the tank was discovered.

Washington Governor Jay Inslee said in a statement last week that the leak posed no immediate health risks. Still, he said the leaking of the hazardous sludge left him “deeply concerned.”

Senator Ron Wyden, an Oregon Democrat and chairman of the Senate Energy and Natural Resources Committee, toured the site yesterday. “This should represent an unacceptable threat to the Pacific Northwest for everybody,” Wyden said after touring the facility, according to the Associated Press.

The leak raises concerns that other single-shell storage tanks built in the 1940s will leak, VandenHeuvel said in an interview.

Temporary Storage

Columbia Riverkeeper wants the U.S. Energy Department to build temporary storage facilities so the waste can be transferred from single-shell tanks. Inslee, a Democrat, also called for the U.S. to pay for interim storage as a waste- processing facility is built.

Doing so could cost millions of dollars when money is scarce. Energy Secretary Steven Chu said in a Feb. 1 letter to Congress that mandatory budget cuts set to take effect on March 1 could delay remediation work at Hanford and other nuclear- waste sites in the U.S.

The leak is the latest setback in a decades-long effort to clean up radioactive and chemical waste from more than 40 years of production of plutonium for the U.S. nuclear weapons program now stored at the 586-square mile facility located in Southeast Washington state, about 170 miles southeast of Seattle.

Nine nuclear reactors operated at Hanford, including the first developed as part of the Manhattan Project, until it closed in the late 1980s.

Bechtel Contract

The leaking tank is one of 149 constructed with a single shell. Built in the early 1940s, it was thought to have been stabilized in 1997 when all pumpable liquids were removed as part of a cleanup effort, the Energy Department said in a Feb. 15 statement announcing the discovery of the new leak.

Washington River Protection Services in Richland, Washington, is transferring waste to more secure storage. So far waste from 10 of the 149 single-shelled tanks has been removed, Rob Roxburgh, a spokesman for the group, said.

Technical challenges in handling the highly radioactive waste means the process won’t be completed for decades, he said.

Jaime Smith, a spokesman for Inslee, said the construction of new storage tanks would accelerate the transfer from the single-shell tanks at Hanford.

Bechtel National Inc., meanwhile, won a contract in 2000 from the U.S. Energy Department to build a processing facility to clean up the remaining waste.

The project has been beset by delays and cost increases, according to the GAO. The estimated price tag of $13.4 billion is about three times the original projected cost. Initially set to open in 2011, the start date is now 2019.

Bechtel began building the processing terminal after several earlier missteps.

“It’s truly a one-of-a-kind scientific challenge when you look at processing the waste at Hanford,” Jason Bohne, a spokesman for Bechtel National, said in an interview. “This not something that has been done before.”