The Hanford Advisory Board is questioning the anticipated choice of what it believes is an unproven technology to clean up uranium in Hanford ground water just north of Richland.
The Department of Energy is facing a legal deadline at the end of the year to propose a cleanup technology for uranium in the soil and water at the Hanford 300 Area.
DOE and the Environmental Protection Agency will make a decision based on that proposal, with EPA having the final word.
DOE has tested a chemical method that would change uranium in a carbonate form that dissolves in water to a uranium phosphate mineral that adheres to rock in the ground water. In theory, that prevents the uranium from moving toward the Columbia River with the underground water.
However, there is concern that because the phosphate that is injected through wells easily binds to the soil, it will need to be injected in a way that allows it to quickly spread out to reach as much of the uranium as possible.
Demonstrations of the technology have not been entirely successful near the Columbia River, the board stated in a letter of advice sent Friday to DOE and the Environmental Protection Agency.
"Its a very interesting idea, but it has not been tested sufficiently," said board member Dale Engstrom.
Much of the soil contamination at Hanford has been removed by digging it up. But the 300 Area uranium stretches to 50 to 60 feet deep over a large area, which would require large amounts of soil to be dug up.
Of particular concern is the uranium deep in the ground near the river where the soil is continually rewetted, allowing more uranium to dissolve into the ground water each time the river rises. As the river rises, the ground water does, too.
Digging up the uranium-contaminated soil in the 300 Area would cost an estimated $1.3 billion and it could cause more uranium to be released in the periodically rewetted zone, said Mike Thompson, a DOE ground water geologist.
The amount of uranium being released to the river now in the 300 Area is 150 kilograms per year. Three irrigation outlets on the Franklin County side of the river release about 1,600 kilograms per year combined, about 10 times that released from the 300 Area, and the Yakima River adds about 4,000 kilograms a year, according to DOE.
If a decision is made to pick the phosphate technology to protect the river, verification and analysis would be done, said Larry Gadbois, EPA scientist.
Should the technology not work, EPA would want other methods evaluated, said Dennis Faulk, EPA Hanford program manager. With federal funding tight, DOE is more likely to get money now for a treatment method picked in a record of decision than for more testing, he said.
"Looking around the country, there is a resistance to innovative technology," said John Price with the Washington State Department of Ecology, a Hanford regulator along with EPA. "I would vote for 'get on with it'."
However, board member Shelley Cimon said it "seems very odd to me to put our eggs in an unproven basket."
The current decision-making process, which includes a remedial investigation and feasibility study and then a proposed plan by DOE for EPA to consider, will serve as a template for similar decisions to follow for cleanup near the Columbia River, the board said.
"It is important to the Hanford Advisory Board that these first river corridor decision documents are dependable, protective, defensible and well supported," the board said. "After a review of the 300 Area RI/FS and Proposed Plan, the board finds that these goals are not met."
Tests performed so far have not provided sufficient information to guarantee a successful implementation of the phosphate technology on a large-scale basis, it said.