Pee on these S.F. walls? Be prepared for them to pee back

Using the wall at 16th Street and Mission as an example, Public Works director Mohammed Nuru demonstrates how the walls deflect liquid onto the clothes of those that urinate on the walls. Using the wall at 16th Street and Mission as an example, Public Works director Mohammed Nuru demonstrates how the walls deflect liquid onto the clothes of those that urinate on the walls. Photo: Cameron Robert, The Chronicle Photo: Cameron Robert, The Chronicle Image 1 of / 8 Caption Close Pee on these S.F. walls? Be prepared for them to pee back 1 / 8 Back to Gallery

Beware, public urinators, some of San Francisco’s walls now pee back.

Public Works crews have finished painting nine city walls with pee-repellant paint and more are in the works. The painted surfaces make urine spray right back onto the shoes and pants of unsuspecting relief-seekers. It’s the city’s latest attempt to clean up urine-soaked alleyways and walls.

“We are piloting it to see if we can discourage people from peeing at many of our hot spots,” Public Works Director Mohammed Nuru said. “Nobody wants to smell urine. We are trying different things to try to make San Francisco smell nice and look beautiful.”

The latest pee-prevention tactic should help curb late-night revelers and indigents who answer nature’s call on city walls, Nuru said.

He demonstrated a painted wall’s effectiveness at the 16th Street Bart Plaza Thursday. A sign reading, “Hold it! This wall is not a public restroom. Please respect San Francisco and seek relief in an appropriate place,” hung above it. It doesn’t explicitly state that the wall will fire back, so some surprises are in store.

“Watch your shoes over there, brother,” Nuru said, spraying water from a plastic bottle against the pee-proof wall. The liquid splashed right back, soaking the bottom of his pants. “The team that did the testing, they were excited because the liquid bounces back more than we thought it would. Anything we can do to deter people is a good thing.”

Public urination has long been a problem in San Francisco. Legislation banning it in 2002 but has seen little success, despite a $50-to-$500 fine.

Since January, there have been 375 requests to steam clean urine. They made up 5 percent of the 7,504 requests Public Works received, which cover everything from feces to pigeon droppings. Overall, steam cleaning requests have dropped 17 percent since last summer, largely thanks to the Pit Stop program that provides public rest rooms.

The paint has proved to be effective in Europe. It was applied to walls in Hamburg’s St. Pauli quarter, where beer drinkers often can’t be bothered to find a bathroom. The experiment captured the attention of San Francisco officials.

“Based on Hamburg, we know this pilot program is going to work,” Nuru said. “It will reduce the number of people using the walls. I really think it will deter them.”

Paint and installation costs a couple hundred dollars for each wall. There are currently nine urine-repellent walls in the Tenderloin, the Mission and South of Market. More are scheduled to be painted next month.

The coating, Ultra-Ever Dry, comes from Ultra-tech, a Florida company in the chemical cleanup and waste management business that also provided the paint for Hamburg. The paint coats an object and creates a surface chemistry and texture with patterns of geometric shapes that have peaks, or high points, that repel most water-based and some oil-based liquids.

So how will the city know it’s actually working? Use your eyes and ears, Nuru said.

“We will send people to see, visually, if there are any wet signs to indicate urination has happened,” he said. “We will also use our natural nose to smell and see if urine is there. If it seems to work, we will continue it after the pilot phase ends.”

Residents are already getting a kick out of the unconventional walls.

“That’s really something else,” Lacey Williams of the Mission said. “People are always doing their business over here in places where it’s not supposed to be done. This is a very different approach.”

Shearie Ely of Oakland added that it will make the city more livable.

“I think it’s a great thing,” she said. “It’s just so nasty right now. I work over here, and I see people using the bathroom all over the place every day. It’s so inhumane, and it smells disgusting. They’re about to get what’s coming to them.”

Lizzie Johnson is a San Francisco Chronicle staff writer. E-mail: ljohnson@sfchronicle.com Twitter: @lizziejohnsonnn

Pee-proof walls

Fair warning, these walls fire back:

Southwest corner of the 16th and Mission Street Bart Plaza

Stockton Street tunnel stairwells

Wall on the Adele Street side of 890 Jackson St.

Wall on the Varney Place side of 98 Jack London Alley

Garage and side door of 3487 17th Street

Osage Alley between 24th and 25th Streets

Garage door alcove at 121 Ninth St.

Minna Street side wall at 145 Ninth St.

496-498 Natoma St.