Dirty drinking water sounds like a third-world problem, to imagine it in a developed nation like the United States seems unfathomable. But not all our water is bottled at a Polish spring in Maine. Some places in the U.S. have nasty water.

In states like West Virginia, Virginia, and Kentucky, rivers and streams are being contaminated with toxic selenium from mining operations. And now it's being reported that microbes which cause Legionnaires' disease, cryptosporidiosis and giardiasis are turning up in U.S. drinking water.

Presented at the International Conference on Emerging Infectious Diseases in Atlanta, representatives from the U.S. Centers for Disease Control and Prevention say sickness due to waterborne illness costs the U.S. healthcare system as much as $539 million a year in hospital-related expenses, with much of that coming from direct government payments via Medicare and Medicaid.

The main culprits are bacteria causing Legionnaires' disease, cryptosporidiosis and giardiasis; many of these microbes are the result of human and animal feces getting in the water - sounds like a Frappuccino from the bowels of hades.

And being unaware about the diseases often leads to more serious medical problems. Infected individuals may think they have a mere case of diarrhea, but it could be much worse, or even deadly.

But events like World Water Day, organized by the United Nations, help educate people about water problems and conversation in the U.S., in places like the Colorado River and the Great Lakes Basin.