It all depends on who you ask.
tainted water

Is The Colorado River Becoming Radioactive from Upstream Uranium Mines?
(via planetsave.com)
Submitted by MaxMaxL on Wed, 2008-06-25 23:50. | Tags: science | Colorado | colorado river | Moab Utah | nevada | radioactive | radioactivity | river | Southern Nevada Water Authority | tainted water | uranium | uranium mining | water