From The Denver Post (Bruce Finley):
Cotter Corp. is preparing to brew a multimillion-gallon uranium cocktail in a mine shaft west of Denver — an innovation aimed at ending a threat to city water supplies.
If all goes well, mixing molasses and alcohol into a stream of filtered water pumped from the mine and discharged down Ralston Creek, and then re-injecting that mix into Cotter’s 2,000-foot-deep Schwartzwalder mine, will immobilize uranium tainting the creek. Bacteria inside the mine will devour the molasses and dissolved uranium, creating solid uranium particles that will settle at the base of the mine, Cotter vice president John Hamrick said. “We believe we can get the water to such a state that it would be OK to let it come out,” Hamrick said in an interview. “We’re using our best efforts to do this as quickly as we can.” Bacteria “will eat the uranium to live, and part of what they excrete, or the byproduct of that, is a solid particle that will fall down to the bottom of the mine.”
The U.S. Environmental Protection Agency has approved Cotter’s project and state regulators were reviewing it.
Such “bioremediation” would save Cotter tens of millions of dollars as an alternative to perpetually pumping out and treating mine water laced with uranium — which reached concentrations as high as 24,000 parts per billion inside the mine shaft, well above the 30 ppb federal drinking water standard…
“The potential is there for this process to work,” EPA environmental scientist Craig Boomgaard said. “Another form of it is being done at Asarco’s smelter in Denver. Is it solution? I can’t say. But in certain cases it is demonstrated to be effective.”[...]
State regulators’ order to pump out and treat uranium-laced water from the mine “has been in place for quite a while and the mine pool drawdown has not yet commenced,” the statement said. “We are eager to see the company move forward.”
More Schwartzwalder mine coverage here.