Water Conservation: Toilet-to-Tap Taboo

On a recent Saturday Night Live skit (23 Sep 2011), Steve Martin interrupted an Alec Baldwin monologue to tell him he needed a steroid test before he could host the program.  Alec goes behind a screen and comes back with a urine sample (?).  Despite all the laboratory equipment that had been wheeled onto the stage, Steve tests the “alleged” sample by drinking it.  This act elicits groans from the audience.  Steve then purports to give an analysis of the sample; clearing Alec to host the show.  While this skit is silly, it does illustrate the need to reconsider our attitude toward our human waste products.

In a recent Time magazine issue (3 Oct 2011), there is an article by Anita Hamilton titled “Droughtbusters, The world is getting thirstier.  Five ways we can keep from going dry.”  The first way listed is “Tackling the toilet-to-tap taboo.”

The idea of drinking water that was once in your toilet bowl may seem like a bad joke, but it’s not.  Stripped of its impurities and rigorously tested to ensure its safety, reclaimed water is one of the most inexpensive and reliable supplies of water on earth.  “This is where we have to use our rational brains to overcome our natural aversion,” says Alex Prud’homme, author of The Ripple Effect.”  In Namibia, the driest country south of the Sahara, such recycled water accounts for 35% of the drinking supply in the country’s capital city of Windhoek.

Interior of Windhoek (Namibia) Water Treatment Facility

Forced through a series of sand and carbon filters as well as ultrafind membranes–some with pores less than on-hundredth the width of a human hair–before being chlorinated and tested for impurities, the treated water is then blended with freshwater. . . .  in a 35% to 65% ratio.

The economics of treating water from the toilet is convincing many to put aside their prejudices.

On a recent trip to a NASA test site in the Arizona desert, I talked to engineers involved in developing technologies for deep space travel.  Of major concern to them is the reuse or recycling of water.  Their space stations will need to be equipped with closed-loop water systems, which will include the recycling of human waste.  One of the technologies they were testing in the desert was forward osmosis (or FO), a water treatment technology which requires less input energy than the better known reverse osmosis (or RO).

NASA Contractor Displaying Bags Used for Forward Osmosis Tests (with Hygene Unit of the Deep Space Habitat Unit in the Background)

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This entry was posted in "Green" Homes, Drinking Water, Engineers Without Borders, Environment, Technology. Bookmark the permalink.

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