Public water supplies in 42 U.S. states--the tap water millions of Americans drink every day--are contaminated with 141 unregulated chemicals for which the U.S. Environmental Protection Agency has never established safety standards, according to an investigation by the Environmental Working Group. Learn more about what may be lurking in your drinking water, what that means for your health, and what public utilities nationwide are doing to make drinking water safer.

_{Photo courtesy of Prasit Imtanavanich}