This story appears in the November 2017 issue of National Geographic magazine.

Along with haute cuisine and chic fashion, there’s another long-standing tradition in Paris that’s decidedly less pleasing. Since before the days of Napoleon, the city of love has battled the odorous scourge of les pipis sauvages, or wild peeing. The widespread practice of public urination is technically illegal. But that hasn’t seemed to stanch the streams that pour into the streets, into planter boxes, and onto lampposts.

What’s a city to do? Try to turn a public misdeed into something resembling a public service. Earlier this year, officials partnered with Faltazi, a French design agency with a fresh idea: installing public urinals in areas known for abundant urination. The receptacle, known as a Uritrottoir, or “sidewalk urinal,” is filled with odor-fighting straw or sawdust. When it’s full, after about 200 “deposits,” a sensor alerts an attendant to empty the contents. The mixture is taken to a site where it becomes compost, and eventually, the compost becomes plant food—“but only for flowers,” says cocreator Laurent Lebot. “Not for any fruits or vegetables.”

Faltazi is testing two models at the Gare de Lyon train station in Paris and in two other French cities in hopes of answering several questions. Will people actually use the Uritrottoir? And if this works for men, could a model also be designed specifically for women to relieve themselves publicly but discreetly?