The sand coming to Idaho from Camp Doha, a U.S. Army Base in Kuwait, was contaminated with uranium after military vehicles and munitions caught fire during the first Persian Gulf War in 1991.
However, also from the fine article:
In a letter to Army officials on Sept. 13, the Nuclear Regulatory Commission deemed the radiation levels "unimportant quantities" and approved the plan to dispose the sand in Idaho.
"We've received tens of thousands of tons from the U.S. military that has higher radioactive levels than this shipment," Hyslop said.
:-)