What smells do you associate with San Francisco?

The rousing, refreshing scent of eucalyptus?

The mouth-watering trinity of Ghirdadelli chocolate, fresh-baked sourdough bread and garlic fries?

Chinatown's heady perfume of Peking duck and sandalwood incense?

The invigorating aroma of saltwater cut with an ever-present whiff of marijuana?

Pee?

You’re certainly not alone if the nose hair-singeing stink of human waste, specifically urine, reminds you of the City by the Bay. In a city so associated with pleasantly potent aromas that even specific neighborhoods have even their own signature scented candles, a distinctive toilet stench also dominates the urban olfactory profile. As far as I know, San Francisco toilet smell does not have its own candle. (But it does have its own Yelp page).

And while a civic fondness of water conservation is the main culprit behind a foul rotten-egg-treated-with bleach bouquet that assaults nostrils during the summer months, San Francisco's pee smell is, well, the direct result of al fresco urination.

Like reading the morning paper in a local park sans pants, urinating en plein air is something of a now-verboten San Francisco tradition — a tradition that was banned in 2012 but has seen little improvement over the past decade. It’s also an activity that Mohammed Nuru, director of San Francisco Public Works, wants to see come to an end. And quickly.

And so, inspired by a community “pee back” initiative in the rowdy St. Pauli quarter of Hamburg, Germany, in which a handful of frequently peed-upon walls were coated with "superhydrophobic" paint, San Francisco now too has a handful of walls that chronic public urinators — wildpinklers as they're called in Hamburg — best steer clear of.

You see, Ultra-Ever Dry, the high-tech paint used in Hamburg and now in San Francisco, causes torrents of pee to bounce off of its target and forcefully spray back — ideally, back onto the pants and shoes of an unsuspecting offender;

In total, nine city walls in the Mission, Tenderloin and SOMA neighborhoods have been treated with Ultra-Ever Dry. More could potentially come.

“We are piloting it to see if we can discourage people from peeing at many of our hot spots,” Nuru recently explained during a demo of the anti-urine paint technology at the particularly malodorous 16th Street BART Plaza. “Nobody wants to smell urine. We are trying different things to try to make San Francisco smell nice and look beautiful.”

Placards that read “Hold it! This wall is not a public restroom. Please respect San Francisco and seek relief in an appropriate place” have been hung on the Ultra-Ever Dry-painted walls to dissuade potential pee-ers but without revealing the surprise that they're in for if they don't heed the warning. The signs are in English, Chinese and Spanish.

The San Francisco Chronicle reports that San Francisco Public Works has received 375 requests to steam clean urine-stained walls since the beginning of the year — roughly five percent of total requests received. The paint, produced by a Florida-based chemical cleanup company isn’t cheap to procure and apply — but not as expensive as steam cleaning.

A sign for a urine-repelling wall in San FranciscoAt least San Francisco's pee-repelling walls give offending tinkelers a bit of a fair warning. (Photo: San Francisco Public Works/flickr)

“We will send people to see, visually, if there are any wet signs to indicate urination has happened,” Nuru explains as to how his agency will knows if the paint is actually working. "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.” He adds: “Based on Hamburg, we know this pilot program is going to work. It will reduce the number of people using the walls. I really think it will deter them.”

Like in St. Pauli, San Francisco’s anti-urination crusade is largely targeted toward inebriated revelers. The spray-back walls will be located in close vicinity to bars, nightclubs and other establishments where full-bladdered patrons are apt to skip bathroom lines and stumble outside of in order to see a man about a horse.

The urine-repelling walls are also in areas that are home to large homeless populations.

While San Francisco, a city long-plagued by a dearth of non-horrifying public restrooms, has made a concerted effort in recent months to provide dedicated facilities to its sizable homeless population, applying urine-repelling paint to walls in areas with a large number of homeless residents does seem a step backwards. Sure, a surprise golden shower might send a clear message to an impatient bar-hopper. But does a homeless individual who wants to relieve himself in privacy indoors deserve to have pee-stained pants and shoes? As far as smells go, isn’t this just making the problem worse?

I’d be curious to see how the pilot pans out — thus far, it seems to be popular amongst residents and building owners anxious to do away with San Francisco's most unsavory scent. I do, wonder, however if concentrating on homeless-heavy areas is the right idea and that funds might be better used to further support organizations that are helping to bring dignified facilities to the city’s transient population. In an ideal world, San Francisco's pee-ricocheting walls would also be equipped with smarts — that is, they'd be able to tell who exactly is doing the peeing: someone who is just being drunk and gross and irresponsible or someone who truly has limited indoor bathroom options.

Via [Reuters], [SFGate]

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Matt Hickman ( @mattyhick ) writes about design, architecture and the intersection between the natural world and the built environment.