Bay Area Rapid Transit authorities plan to use enzyme mists and open underground restrooms in an attempt to reduce odor-causing bacteria in subway

So far, the elevator shaft at the Civic Center subway station in San Francisco still smells.

That won’t surprise many a subway passenger around the world who knows the signs of an elevator to be avoided: stale air, the tang of ammonia, rancid hints that someone felt they had no choice but to relieve themselves.

But the authorities of the city’s subway, Bay Area Rapid Transit (Bart) have decided to take up the good fight, testing biological means to attack the bacteria that thrive in subways, not just on urine, but more so, experts say, on trash and sewage.

In the Civic Center elevator shaft, a “Urine-B-Gone System” uses a “triple enzyme cleaner”, to self-pump water and spray a mist of enzyme cleaner down the shaft “to kill the bacteria responsible for causing the smell in urine”, said Alicia Trost, a Bart spokeswoman. The enzymes break down bacteria as the microbes would garbage, “leaving a very slight lavender aroma”.

The lavender didn’t present itself on a recent visit to the elevator shaft. It didn’t smell like urine – it was even a little sterile. But it wasn’t a nice smell.

“It isn’t just urine that causes the smell,” said Alicia Trost, a Bart spokeswoman. “Some smells originate from the elevator shafts deep below.”



People who can’t contain themselves bear only some of the blame for the malodor, experts say: trash, sewage and other sources are generally greater contributors to the stench. Trost said that most of Bart’s elevators are 45 years old and built of porous concrete, which allows material to seep into shafts – colloquially called “the pits”.



“There are other things that cause odors such as natural underground springs, storm water drains, and tidewater,” she said, adding that a shaft only 12ft below the surface can easily flood and become a catch basin.



Whether bodily waste, scraps of a Big Mac or the castoffs of $6 avocado toast, all of it is a feast for bacteria, which breaks down into a liquid – sometimes explosive – mess. That pile ferments into noxious gases, which drifts up to haunt the people who left it behind – and the people who came after them.

Public bathrooms are a rarity in major subway systems, and the Bay area has kept its bathrooms locked since 2001, when national security officials told Bart officials that single bathrooms with ceiling-to-floor doors were a security risk. The Bart board of directors has since worked on plans to reopen and new designs, including shorter doors, public sinks and blue lights to deter drug use.

“The ultimate way to get rid of the smell is to stop people from pissing in the elevators,” said Nick Josefowitz, a solar power businessman and member of the board. “I think at the time everybody was concerned at having sort of private places where people could go and get up to mischief in underground subway stations.”

Josefowitz said that Bart will open two underground restrooms over the next 18 months as a pilot program, and that he felt public restrooms were a basic privilege. “People are commuting almost an hour in our system, and if you’ve got to go, you’ve got to go – old, young, poor, rich, whatever.

“My wife and I just had kids, they’re in strollers, and we can’t take them down the elevators. It stinks. It’s just gross.”

San Francisco has one of the highest populations of homeless people in the United States, many of whom turn to the subway for shelter. Josefowitz said the city and its environs have an obligation to reconsider its public services. “We have these problems that seem endemic, but with the resources that we have available, we constantly need to be revisiting them and pushing them forward.”

Trost said that the pilot program would spray into elevators and pits every hour, but that Bart authorities were prepared to act as needed. “You can set the mist to occur as frequently as needed.”