Fun fact: 250,000 gallons of water are used every day to heat buildings in San Francisco’s downtown sector, with some of it coming from groundwater reserves.
San Francisco’s infrastructure is old, especially its sanitation system. An analysis done in 2017 found that SF’s sewers are aging at an alarming rate; at least 30% of its sewers were more than 100 years old, with another 60% of them being 80-plus years old. Mind you: That study is years old, so these sewers have only gotten older.
Large amounts of steam which is used to heat buildings in the downtown area is pouring out of a manhole at New Montgomery St. and Market St. There is no danger to the public but drive/walk safely around the area. Crews from the utility company responsible for maintaining the… pic.twitter.com/tq1t85slnB
— SAN FRANCISCO FIRE DEPARTMENT MEDIA (@SFFDPIO) March 29, 2024
SF’s first sewers were made of then-traditional brick construction, installed between the 1860s and 1880s. They simply emptied into a collection of nearby creeks, marshes, and the SF Bay Area. Because these sewers were combined with both stormwater and sewage, the smell of human waste was pungent.
Though (thankfully) the wafting odor of rotting human feces is no longer, San Francisco remains the only major city in California to still utilize that aforementioned sewer system type; most major CA cities, like Los Angeles, have since evolved to designs that collect, treat, and manage stormwater and sewage separately.
It’s the reason why spelunking inside SF’s sewer system is so dangerous… because you could be exposed to a bacterium capable of causing a lethal infection. It’s also why steam — heated vapor is still used to heat residential, government, and commercial buildings in downtown SF; that steam, once having left connected feeder pipes and radiators from underground boilers, is emptied into the sewer system — sometimes erupts out of them through manholes in spectacular fashions
That’s exactly what happened at the intersection of New Montgomery and Market streets on Thursday, March 28th when passersby took note of the unusual amount of vapor spewing from a manhole.
“Large amounts of steam which [are] used to heat buildings in the downtown area is pouring out of a manhole at New Montgomery St. and Market St.,” reads a post on X from the San Francisco Fire Department (SFFD), assuring people that there was no immediate danger… despite the volcanic-like display.
“There is no danger to the public but drive/walk safely around the area,” the post continues. “Crews from the utility company responsible for maintaining the underground pipes are responding. SFFD and SFPD are on scene.”
According to Cordia, the utility that operates and maintains SF’’s downtown steam system, over 37 million square feet of commercial, residential, and government buildings are heated by steam; the collective area served in downtown SF by Cordia is about two square miles.
While heating with steam sounds eco-conscious, it’s quite the contrary. Cordia was shaded in 2015 for using nearly 250,000 gallons of drinking water per day to feed steam through the system. In the wake of that criticism, the company later partnered with a local water reclamation project to pump 30 million gallons of groundwater annually from beneath Powell Street Station, mitigating the need to use SF drinking water. (Using some elementary math, the use of this groundwater, in theory, supplies enough water for 120 days of operation for Corida’s downtown steam system in San Francisco.)
Just when you think you know everything about this ostensibly small city, another quirk pops up — quite literally, in this case.
Feature Image: Screenshot courtesy of X via [at]SFFDPIO
