Urination and defecation are human needs that the modern city handles very well, in private at least. Mass centralized sewage systems and waste treatment facilities take away our bodily waste and deal with it so we don’t have to.
But in public, cities have a much spottier record of addressing these needs.

In San Francisco, a movement to add more public restroom facilities to the city is gathering steam. Organizers would like to specifically target neighborhoods like the Tenderloin, which has a high concentration of homelessness. According to a recent article in the New York Times:

There were nearly 10,000 documented "incidents of human waste" cleaned up last year in the Tenderloin alone, according to Dina Hilliard, executive director of the North of Market-Tenderloin Community Benefit District, a neighborhood improvement effort financed by local property owners that pays for sidewalk cleaning. "This is out of control," Ms. Hilliard said of the waste.

One approach to combating the problem is to build the restroom equivalent of the city’s innovative "parklets," which are small public spaces built to fit within a few street parking spaces. "Pooplets" could provide publicly accessible toilet facilities. And through advances in composting toilet technology, these public toilets wouldn’t need to have expensive plumbing or sewage system hookups, keeping the cost at an estimated $40,000 to $50,000.

The North of Market/Tenderloin Community Benefit District has been working with Hyphae Design Laboratory to develop a prototype, which could be installed in the Tenderloin by summer.