In situ Leach Uranium Mining
The naturally occurring uranium resource recoverable through in situ recovery (ISR; also known as in situ leaching) uranium mining is present
in Carter County near Alzada, and exploration drilling occurred across the state line in Wyoming. ISR mining involves the injection of an
oxidized solution into groundwater that dissolves uranium minerals. Factors that can contribute to the unintentional migration of recovery
solution into groundwater include equipment failures, aquifer heterogeneity, fractures, or improper well completions. In Carter County, the
uranium mineralization occurs in proximity to the aquifer utilized by residents, the Lakota sandstone. In this far southeast corner of Montana,
residents often have to drill 1,000 to 3,000 feet below the surface to tap into this aquifer. ISR solution excursions have the potential, therefore,
to impact domestic water supplies. The MBMG and the Custer Conservation District performed a baseline groundwater quality survey of the Lakota
aquifer in the Alzada area in 2009 and 2010.
Related Publications and Data
Stock wells near Alzada, Montana can exceed 3,000 feet in depth.
Photo by Elizabeth Meredith
In situ uranium production in Wyoming occurred near Hulett, Wyoming, home to Devil's Tower.
Photo by LeAnna Johnson
Elizabeth Meredith fills a dissolved radon sample bottle near Alzada, Montana.
Photo by Shawn Kuzara
Uranium can be extracted from aquifers through the injection of a leaching solution that mobilizes uranium into the groundwater that is then brought to the surface.