Almost 12 million tons of radioactive waste (search) will be moved from the banks of the Colorado River, the source of drinking water for more than 25 million people across the West, the government said Wednesday.

Energy Department officials on Wednesday cleared the way for a plan that was announced earlier this year.

The 94-foot high pile of uranium mining waste is near Moab, Utah (search), and 750 feet from the river. The department now will work on the specifics of moving the waste to a site at Crescent Junction, more than 30 miles northwest.

Concern that contaminants would leach into the Colorado River was heightened in January by flooding in southern Utah.

Moab's rich uranium deposits were mined for nuclear bombs starting in the 1950s. The Uranium Reduction Co. sold its mill in 1962 to Atlas Corp., which ran it sporadically until declaring bankruptcy in 1998. The Energy Department took over the site in 2001.

Left behind was a 130-acre uranium mill tailings pile, which is mostly in the open air on bare ground, surrounded by a chain-link fence.

"This decision demonstrates our commitment to fulfilling our Cold War cleanup obligations as well as preserving the long-term environmental health of the river and the many communities it serves," Energy Secretary Samuel Bodman (search) said in a statement.

Utah Gov. Jon Huntsman, a Republican who lobbied the Bush administration to move the waste, said the development "was great news for Utah and the millions of people who rely on the Colorado River for their water supply."

The cleanup cost is expected to be more than $400 million. The department estimates it will begin moving the tailings in 2008 and finish by 2014, department spokesman Mike Waldron said.

The tailings will be moved, predominantly by rail, to the proposed site in Crescent Junction. They will be covered and buried in a hole lined with a protective layer to prevent leakage into the groundwater.