Leave it to the faux news genius to make the unthinkable both plausible, politically correct and hilarious. In an interview with Robert Glennon, author of the new book "Unquenchable: America's Water Crisis and What to Do About It", Stewart pops the obvious question in response to Glennon's description of innovative ways to reclaim potable water for human consumption from the sewage treatment process. In fact, Glennon believes, this is one of the low hanging fruit in what is rapidly becoming an urgent problem facing America.

A growing chorus of conservation voices is calling for better capture of so-called urban runoff to be used to help reduce how much water the U.S. takes out of its rivers, streams and lakes and puts through its sink, faucets and toilets. Stewart asks Glennon when the crisis will hit and the author, a law professor at the University of Arizona, basically says the crisis is already hitting and it's only going to get worse in the near term.

This is hardly news to folks in the western U.S., who have faced water shortages and usage restrictions for years. California, in particular, has been hard hit by droughts. But lately water supply problems have hit crisis levels in some unexpected, wetter climes such as Atlanta, Georgia. In China, the Central Government recently raised water prices to encourage conservation by industrial and commercial users. China, like the U.S., faces a growing water crisis as its burgeoning cities consumer more and more of the country's limited supply.

In fact, drinking toilet water is already something that residents of Orange County, California do. And other communities around the U.S. are examining this as a way to save water. But Glennon points out that while conservation of residential and city use is essential, many initiatives designed to save the environment or to provide clean, green alternatives to fossil fuels are actually hugely water intensive. For example, producing a single gallon of ethanol requires far more than a gallon of fresh water (estimates vary from four gallons to 20 gallons). So avoiding a fuel crisis creates a water crisis.