By Laura Snider
Boulder Daily Camera
March 26, 2008
Foes fear contamination
There are two major types of uranium mining:
- Historically, the most common method was to remove the uranium ore using either open-pit mining -- which scrapes off all the land above the uranium deposit -- or underground mining. The uranium-containing rocks were then transported to a mill where the ore was crushed and processed, leaving behind mounds of uranium tailings.
- More recently, in-situ mining has taken off in Texas, Wyoming and Nebraska. This method mines the uranium in place by flushing the uranium ore with oxygenated water. The water dissolves the now-oxidized uranium and can be sucked to the surface via a well. The surface disturbance for in-situ mining is far less, but there are concerns that the process contaminates nearby groundwater supplies.
A proposed uranium mine in Weld County would tap into an aquifer that lies deep beneath the Denver Basin and sweeps through the southeast corner of Boulder County.
Opponents of the mine -- who fear massive groundwater contamination -- are holding a public meeting tonight in Longmont.
"The aquifer has been used for drinking water for a long time," said Jackie Adolph, spokeswoman for Coloradoans Against Resource Destruction, the group sponsoring the meeting. "There is a real risk of cross-contamination."Canadian-based Powertech Uranium Corp. is part of a new "uranium rush" stimulated by a nearly 2,000 percent increase in the market prices for uranium between 2000 and 2007 and a glut of recently proposed nuclear power plants across the United States.
Powertech is studying the feasibility of mining about 4,750 tons of uranium from its claims in Weld County, though the company has yet to apply for a permit.
A complex basin
The mine would principally use in-situ leaching to remove the ore, a technique that flushes the uranium with oxygenated water, dissolving the uranium before sucking it to the surface. Because the water is drawn from the aquifer surrounding the uranium ore, critics of the process argue that it's impossible to guarantee that the newly mobile uranium won't escape into parts of the aquifer that are tapped by residential wells.
The Denver Basin holds four aquifers stacked on top of one another, and the Laramie-Fox Hills Aquifer, which is home to the uranium ore in Weld County, is the deepest. Mine opponents fear that any contamination of the Laramie-Fox Hills aquifer could spread throughout the entire system, which underlies land bounded by Greeley, Golden, Colorado Springs and Limon.
"It's a very complex setting subsurface," said Travis Stills, an attorney for the Energy Minerals Law Center in Durango. "You have fissures and all kinds of things going on, including old well bores causing connectivity between the aquifers."
Colorado's history of uranium mining digs back to 1971, when the radioactive mineral was discovered at a gold mine in Central City. Now, Colorado is home to thousands of abandoned mine sites, including the Fairday mine outside of Jamestown. As uranium prices crashed in the 1980s, mines across the state closed, leaving only the Sunday mine outside Uravan operating today.
Cleaning the groundwater
In-situ leaching is a relatively new technique of extracting uranium, which is being used now in Wyoming, Nebraska and Texas. But there are still lingering questions about whether the groundwater surrounding the uranium cores can ever be fully restored to its pre-mining state. Powertech argues that it can and will.
"We're required to return the water to the original use category," said Richard Clement, president of Powertech. "That's the goal of restoration. In Texas, especially, approximately 20 mines have been fully restored."
In-situ leaching requires a dense network of wells, with outer wells injecting oxygenated water into the aquifer and a central well pulling the water -- now laden with oxidized uranium -- back to the surface. The water is then treated, oxygenated and re-injected. Mining companies claim that the cycling of water will, eventually, flush all the mobile uranium out of the aquifer, leaving the water as safe as it ever was.
Critics say the method has never actually worked.
The Corpus Christi Caller-Times examined 32 permits from closed south Texas in-situ mining sites and found that the companies only met restoration standards because the standards were changed.
"In each case, companies were permitted to leave behind minerals such as uranium, molybdenum and selenium at higher levels than were listed in the original permit," wrote reporter Dan Kelley in November 2006.
Two bills circulating in the Colorado General Assembly would tighten restrictions on in-situ mining. House Bill 1161 would require mining companies to provide evidence of at least five similar mining operations that did not result in groundwater contamination before a permit could be issued. The Energy Minerals Law Center said Powertech is vigorously fighting the legislation.
"1161 puts a provision in that requires them, as the Missourians say, to show me," Stills said. "When they're telling folks how well they're doing, they're saying, 'No problem.' When they visit the legislature, they say, 'You can't make me do this.'"
Contact Camera Staff Writer Laura Snider at 303-473-1327 or