San Francisco’s anti-pee walls are making a splash

The city of San Francisco has come up with a novel way to deal with the problem of public urination.

It has trialled urine repellent walls that are decorated with paint that sprays the noxious liquid right back at those who use them as a free toilet.

Ultra-Ever Dry is a clear liquid repellent that goes on like paint but causes any urine that comes into contact with it to be sprayed back on to a person's shoes and trousers.

The superhydrophobic coating costs about $200 (£129.28) to apply to each wall, and it essentially gives the concrete a waterproof layer.

Mohammed Nuru, director of the city's public works department, said he got the idea from similar projects in Germany.

In Hamburg, the same paint is used to deter those who urinate in public.

The initiative was launched after the city's public works department received 375 requests to steam-clean urine from walls.

This made up five per cent of its total calls.

Speaking about the initiative, Mr Nuru said: "We are piloting it to see if we can discourage people from peeing at many of our hot spots.

“Nobody wants to smell urine. We are trying different things to try to make San Francisco smell nice and look beautiful. The team that did the testing were excited because the liquid bounces back more than we thought it would. Anything we can do to deter people [urinating in public] is a good thing.”