What fertilizes urban roof gardens in the Netherlands?

Answer: the public's urine

by / March 13, 2014

In Amsterdam, the nation’s utility company, Waternet, stationed urinals in public places with the hope that the liquid might later be turned into fertilizer for the city’s urban roof gardens. The program serves the dual purpose of providing a source of phosphorous for fertilizer, and also reduces stress on the city’s pipes, which can become clogged from crystallized phosphorous.