A highly unpleasant odor is causing a stink in the Lower Haight, as a sewer repair effort permeates a chemical odor throughout the neighborhood, but the SFPUC insists there’s no public health hazard.

San Francisco has never been known as a particularly pleasant-smelling city, especially during the muggy months we’re heading into. But as the Chronicle reports, an unusually foul odor is percolating through the Lower Haight, as well as parts of the Castro, Duboce Park,  and the Panhandle, with the smell drawing comparisons to acetone, burning plastic, or paint thinner.

“You know it's a chemical when you smell it,” Lower Haight resident Augie Phillips told the Chronicle. “You’re like, ‘That's something nasty.”

But there’s apparently no foul play to this odor, it’s a smell being caused by a city-sanctioned project to fortify century-old underground sewer pipes. The SFPUC more specifically describes the effort as the Panhandle and Inner Sunset Large Sewer Rehabilitation Project, and as seen in the map above, this is also happening on a small stretch of Seventh Avenue between Lawton and Judah streets. The smell comes from a “polystyrene resin adhesive” that will reline the sewer pipes to make them more stable, a method the SFPUC feels is less obstructive than digging up the street.

SFPUC spokesperson Joseph Sweiss insisted to the Chronicle that “there are no concerns for public health,” adding that workers have been regularly gathering real-time air quality data to ensure that the air is safe. He said that the odor will “typically dissipate quickly,” though just how quickly can depend on the weather that day.

The SFPUC also recommends that residents in affected neighborhoods can cover their sink and shower drains with a towel to keep the stench from getting indoors, which does not sound reassuring. Of course, an inconvenient odor is probably a better alternative to having sewer pipes burst into disrepair. But Lower Haight residents who think this arrangement stinks to high heaven will not be thrilled to learn that the SFPUC says this project is slated to last until  “Spring 2024.”

Related: Mysterious Stench Returns With A Vengeance, Chevron Facility In Richmond Suspected Culprit [SFist]

Image via Google Street View