A@W Newsletter

Austrian design studio EOOs has developed the world’s first urine-diverting toilet. Photo: EOOS

In the world of bathroom design, many products are geared toward reducing water consumption. But toilets are by far the biggest wasters. That could change with save!, a toilet that diverts waste and turns it into crop fertilizer.

Now available in pre-order, the Rainstick saves up to 80% of water and energy typically wasted during a shower. Photo: Rainstick Shower.

Science has proven time and again the biggest challenge facing the planet and our existence is climate change—a notion that COVID has only reinforced. The pandemic brought the world to a halt. It has also forced many industries to consider the impending risk of overpopulation and increased urbanization—conditions that are bound to lead to scarcity in space and resources. Or, even worse, the potential to collapse economies and entire ecological systems. However, in times of duress, nobility and beauty have ways of finding their way through the cracks, prompting us to think and work in new ways.

Hansgrohe’s eco-smart technology can save up to 60 percent of water used by adding air. Photo: Hansgrohe

One reality all countries share is an overuse of water. For years, the sanitary industry has invested in solving this life-threatening crisis and it has come up with impressive, and above all, feasible concepts. As just one example, a newly launched clean technology start-up based in Kelowna, B.C. has developed a shower system that recirculates water. Called Rainstick, it saves up to 80% of the energy and 80% water without reducing flow rates.

The most widespread water-saving initiative is the low-flush toilet. Yet, while it represents an important step in reduced consumption, it only tells half of the story. The more significant problem is that most of us aren’t using it properly. After all, how often is the big button on top of the tank pressed after the “small business” is conducted? Functionality that is reliant on good human behaviour isn’t a realistic solution.

With Roca’s W+W, sink water is collected for the next toilet flush. Photo: Roca

Of all the faucets we use, toilets are the most water voracious and, thus, that is where opportunity lies. Among the most promising concepts is save!, a toilet that can separate urine from wastewater with every flush. Developed with support from the Bill and Melinda Gates Foundation and through years of research conducted by the Swiss Federal Institute of Aquatic Science and Technology (EAWAG) and the water research institute at ETH, it has now reached a critical stage of realization. Swiss bathroom manufacturer Laufen has brought the toilet to market with a version designed by EOOS, which is also responsible for inventing the Urine Trap, the mechanism that allows urine to be inconspicuously separated into its own wastewater stream without user’s ever knowing.

The urine separation toilet save! from Laufen contributes to protecting rivers and seas. Photo: EOOS

The separated waste is then rapidly and easily processed using backend systems. Nutrients are recovered by methods that involve biological stabilization, activated carbon filtration and evaporation. Eventually, the waste is converted into a fertilizer concentrate rich in nitrogen, phosphorous and potassium, which are all essential for plant growth.

Save! now meets the latest industry standards, and the Swiss Federal Office for Agriculture has approved it for use on crops. Tove Larsen, a specialist in urban water management at EAWAG, has said of the toilet: 

“It represents a 21st-century breakthrough that will save our rivers and oceans.” In other words, save! is not just a product; it is a wake-up call that has real environmental impact, and just when we need it the most.

Originally written by Barbara-Jahn Rösel