From the Fort Collins Coloradoan (Bobby Magill):
If approved, Powertech will be allowed to test the feasibility of in situ leach mining for uranium at the Centennial Project site. The test could help regulators find answers to questions about how the underlying aquifer works and how any contamination from the mine could move through it and affect groundwater elsewhere…
The mining could have the greatest impact on the Laramie-Fox Hills aquifer, which many surrounding landowners have tapped for their well water.
The councils of most of the surrounding cities and towns, including Fort Collins and Greeley, have said they oppose the mine, partly for fear it could pollute the groundwater.
How far any pollution from the mine could spread within the aquifer and how that could affect water wells in the area isn’t well understood, but the pump test could shed some light on the matter, according to the EPA…
Information about the hydrogeology of the aquifer is sparse, and few people have studied how fast water moves in the aquifer to determine how pollutants could spread…
Vincent Matthews, state geologist and director of the Colorado Geological Survey, pointed only to a 1980 CGS study of hydrogeology and uranium resources northeast of the Centennial Project site, written at a time when Unocal and other companies were planning uranium exploration projects near Keota in Weld County. The state sampled 104 water wells — many of which tapped the Fox Hills formation — near uranium deposits in northern Weld County. The study showed that the well water quality was extremely poor and much of the water contained high levels of uranium and vanadium. The closer a well was to a uranium deposit, the more contaminated it was. But, Matthews said, the study doesn’t say much about what’s happening in the same aquifer and rock formations near Nunn…
The USGS has no specific data on the Fox Hills aquifer near the Centennial Project, and any other studies conducted in the area wouldn’t apply to that spot because each site has its own unique characteristics, said James K. Otton, a USGS geologist specializing in uranium. Otton last year wrote a brief on in situ leach uranium mining, saying the mines have always left increasing contamination behind and no one has ever succeeded at fully cleaning up the groundwater after an in situ mine has shut down.
