Posit the question “How do they clean the sewers in San Francisco” and you'll be surprised. Unless, of course, your answer was “They roll out a device resembling a Victorian-era laboratory contraption painted tomato red, emitting more noise than a diesel locomotive, and employing technology more often seen in fountains and vacuum cleaners.” If that was your answer — you're on the money.
As to what, exactly, the Department of Public Works is cleaning out of the sewers with the aforementioned contraption — there, too, you'll be surprised. The answer we were given Monday at the corner of Fourth and Berry was “bricks from 1860.”
Here's how “The Sewer Hog” and “The Grit Gator” work: