Researchers have found that two major aquifers in the U.S.--High Plains and Central Valley--contain levels of uranium that far exceed the EPA's maximum acceptable standards.

Safe drinking water is crucial to basic health, and a study has found that many Americans could be at risk. 

Researchers have determined that two large aquifer sites in the U.S. contain levels of uranium that exceed maximum standards set out by the Environmental Protection Agency, or EPA. 

The nation’s largest High Plains aquifer, which serves eight states including Nebraska, South Dakota, and northern Texas, contained as much as 89 times the acceptable levels. 

Meanwhile, the Central Valley aquifer, which is the s