J. wrote back in February, when it was a bit chillier, but I still wanted to follow up on this one: “It’s baffling that we can complete a mission to Mars but after years and years, the manholes at West Broadway & Warren will keep billowing steam. What exactly is the chronic problem at this intersection?”

So ordinarily the orange and white “chimneys” are meant to divert steam leaks from the city’s steam system, which runs underground and heats, cools and humidifies buildings around the city. The system goes back to the 1880s and is now managed by ConEd’s Steam Operations, providing steam service to over 1,700 commercial and residential customers in Manhattan from Battery Park to 96th Street. It’s the largest commercial steam system in the world.

There are leaks throughout the system, which condense especially in the winter. The chimneys make it so drivers aren’t blinded by a huge cloud of steam coming up from the manholes — they simply divert it above windshield height.

HOWEVER, when I got in touch with ConEd earlier this month, reps said that the recent chimneys at this particular intersection are not for a leak in their system, but rather to support DEP sewer work. “We placed our steam stack at the site on Feb. 20 and will continue to accommodate the scheduling of the DEP work.” The permits they looked up for me go through May 20.

I could of course now follow up with DEP, but I think that’s all I can handle for now.