Why Flush Toilets Are Wasteful

March 23, 2022

It's possible to get rid of human waste more efficiently

milk jug filling a toilet tank

Every time a toilet flushes, a gallon and a half of clean, treated water is wasted.

“We use drinking water to flush our toilets,” said Lena Trotochaud, a research scientist with the Duke University Center for Water, Sanitation, Hygiene and Infectious Disease (WaSH-AID). “And as climate continues to change and water becomes more scarce, and we have more droughts and more fires, we’re going to be using more and more drinking water and having less and less of it. We really need to conserve that precious resource.”

WaSH-AID is engineering a new kind of toilet—one that treats human excreta onsite, with ultrafiltration processes that leave the liquid fraction of the waste clean enough to use for flushing. The “Reclaimer” toilet is currently being tested at a textile mill in India, but Trotochaud said it could also be used in drought-stricken areas of the U.S. that are experiencing rapid population growth, in the future.

The toilet was the subject of a recent short video produced by Sci NC, a PBS North Carolina program, which can be viewed below.

Learn more about the Reclaimer on Duke Engineering’s podcast, Rate of Change.

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