The Future Of Drinking Is Drinking Water That’s Been In A Toilet

Here’s a secret: You probably already are. But as we need to find ways to conserve water, treated wastewater may become a more obvious part of what we drink. The trick to making that work isn’t technological, it’s psychological.

Linda MacPherson studies water in a place where the resource does not, for a good portion of the year, appear to be in short supply: Portland, Oregon. But the same does not hold true everywhere. The world is facing a water crisis and, in the developed world, the water crisis is being fought along two fronts. On the one hand, pilot plants in San Diego and a national “NEWater” program in Singapore show that it’s both possible and practical to reclaim and reuse wastewater into clean drinking water. Yet, this process poses another problem–a cognitive one.
MacPherson, the owner of New Water ReSources, recently produced a video, called Downstream, as part of her advocacy work, to emphasize the obvious: We’re all drinking water downstream from somewhere. “Treated waste water discharges going into rivers and streams becomes the source of drinking water supply for people downstream and that’s been going on forever,” she says. “You just don’t talk about it.”


To make matters worse, she says, opponents of water recycling projects have a catchy name that sounds outright disgusting: toilet-to-tap. “People feel like, ‘Oh my gosh, this is really unusual.’ We know from psychological research that the things that appear to be novel and unusual are oftentimes more alarming and create more of a perception of risk.”

Consider what’s known as the law of contagion. In one classic experiment, psychologists Paul Rozin and Carol Nemeroff dipped dead, sterilized cockroaches in glasses of juice. They found that young adults, not all that surprisingly demonstrated a strong aversion to “roached” drinks–even when the bugs were long gone. In other words, in the absence of perceptible differences like taste or smell, they were grossed out by the history of contact.
Likewise, water doesn’t just come down from the clouds, brand new, fresh as the day that hydrogen first joined with oxygen in the two-to-one ratio. Every molecule of water has been around the block. The stuff the Pharoahs drank is still floating around the world today and at some point it may have come in contact with something you didn’t like: Mitt Romney and Barack Obama take showers; kittens have been drowned in rivers; billions of people all over the world spit and bleed and defecate. If you think drinking water downstream from a treatment plant is normal, but the thought of going direct from the sewage tank to the water fountain seems just plain gross, then MacPherson would like to reiterate her point: “The history of where water has been has nothing to do with the quality of the water.”

Despite the fact water engineers have the technology to make ultra-pure water, she says, and the more advanced techniques–reverse osmosis, advanced oxidation, or filtration–can remove harmful chemicals down to parts per trillion and parts per quadrillion, the powerful notion of disgust persists. This psychological front represents the biggest challenge to the future of clean water. How do you break the cognitive link and remove the psychological sewage after the actual sewage is long gone? One way might be adding successive rounds of purification or even sticking cleaned water back in a river or a stream (although Nemeroff points out: “The irony is that when you put this ultra-pure water in the natural world, it’s actually making it dirtier to become acceptable.”)
In the end, disgust might take a back seat to necessity. Before we get there, though, MacPherson would also like like to come up with an ingenious campaign to rebrand recycled water on the merits of what it is, not what it was. Care for a glass of source-to-tap-and-back? In other words: a glass of the water you’ve been drinking all along.

For more videos and stories on innovative solutions in food technology, check out the rest of our Feeding the Future series.