Public nuisances can lead to innovation in San Francisco:

The city’s Public Works agency is testing a pee-repellant paint on walls in areas that have been saturated with urine. Anyone urinating on the specially treated walls will get the spray splashed back onto them.

San Francisco’s director of public works, Mohammed Nuru – whose Twitter handle is @MrCleanSF – got the idea when he read on social media about the use of the paint in Hamburg, Germany’s nightclub district to stop beer drinkers from relieving themselves in the street.

The paint, called Ultra-Ever Dry, is sold by Ultratech International Inc and is billed as a superhydrophobic coating that will repel most liquids…

In a pilot program, San Francisco last week painted nine walls in areas around bars and other areas with big homeless populations.

This may be welcome in many places. Yet, the lack of bathrooms in many major cities is a big issue. For example, Mitchell Duneier has a section in his ethnography Sidewalk on the issues homeless black street vendors have in finding facilities. The paint may help deter people – particularly those around bars who could use the restrooms there – but doesn’t address the bigger concerns about clean public restrooms.