The Netherlands’ government-owned Waternet utilities company has recently placed sets of pee-collecting urinals around Amsterdam (but oddly not in Waterlooplein), with the intention of turning it into fertilizer for the city’s urban roof gardens.
The idea derives from the fact that urine contains phosphorous, a key ingredient in for fertilizer that is a non-renewable resource facing depletion, with some environmental experts predicting that the world will run out by the end of the century. Urine also causes problems for companies like Waternet, because the phosphorous crystallizes and clogs up pipes. As a solution to both problems, the company placed public urinals around Amsterdam. Rather than sending the wastewater through sewage pipes like traditional lavatories, the urine is instead collected and sent to a recovery plant, where the phosphorous is filtered and turned into fertilizer. The campaign coincides with new Dutch laws that enable the agriculture industry to use human waste on farms. Waternet’s fertilizer will be used to give back to the city, with urban rooftop farms benefitting. The 400 year-old utility also plans to open a waste treatment plant that will produce 1,000 tons of fertilizer annually by the end of this year.