Anarchist response would be “people who want functioning sewers, which should be everybody.”
Yeah it’s a dirty job. So is wiping your ass. Does someone need to threaten you to wipe your ass? Take a shower? When your toilet breaks at home do you shrug and just shit on the bathroom floor?
No, you fix the toilet. Same with the sewers.
Whoever steps up first. For a sewer, probably several people. What’s your point?