You Already Drink Crap

Science, technology, and life.
April 2 2009 9:53 AM

You Already Drink Crap

It's been a year or so since we checked in on " toilet to tap ," the increasingly useful art of turning sewage into drinking water . Actually, you aren't supposed to call it "toilet to tap." That's a slur coined by political opponents of the technology. And it's highly effective, as evidenced by the fact that I've probably grossed you out already.

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William Saletan William Saletan

Will Saletan writes about politics, science, technology, and other stuff for Slate. He’s the author of Bearing Right. Follow him on Twitter.

The technology's proponents constantly labor to explain how sanitary it is. Their latest attempt, via Reuters , focuses on Orange County's " Groundwater Replenishment System ":

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Anyone who has visited Disneyland recently and taken a sip from a drinking fountain there may have unknowingly sampled a taste of the future—a small quantity of water that once flowed through a sewer. ... The plant takes pre-treated sewer water that otherwise would be discharged to the ocean and runs it through a three-step cleansing process—essentially the same technology used to purify baby food and bottled water. Thousands of microfilters, hollow fibers covered in holes one-three-hundredth the width of a human hair, strain out suspended solids, bacteria and other materials. The water then passes to a reverse osmosis system, where it is forced through semi-permeable membranes that filter out smaller contaminants, including salts, viruses and pesticides. Reverse osmosis also is the main process used in desalination.  Finally, the water is disinfected with a mix of ultraviolet light and hydrogen peroxide. The resulting product exceeds all U.S. drinking standards but gets additional filtration when it is allowed to percolate back into the ground to replenish the aquifer.

Well, that sounds pretty clean. But I bet you're still not convinced. You'd rather stick to the familiar crap-free water that already comes from your tap.

Surprise! That familiar water isn't so crap-free after all. And proponents of the new technology are happy to tell you so:

They want the public to understand that much of what comes from the tap today is recycled sewer water. The Colorado River, for example, contains large amounts of heavily treated waste discharged from cities upstream, including Las Vegas. As the L.A. County Economic Development Corp study puts it, "What happens in Vegas doesn't stay in Vegas."

Great line. And it's smart politics: If you can't sell the public on the purity of your own candidate, attack the other side's candidate. We're used to this tactic when the candidates are people like John McCain and Barack Obama. But it works just as well when the candidates are groundwater replenishment and old-fashioned tap water.

And just because this is a political attack doesn't mean it's false. For my money, it's true. We already drink toilet-to-tap water. That's the nature of water: It cycles from one form to another. Urine evaporates, rain falls, rivers flow. If you think you've never consumed water that came from excrement, you must literally be living on another planet.

So stop freaking out about where your water came from, and start focusing on the quality of its filtration. Everything is recycled, including you.