A few years ago, many of us became acquainted with a singularly revolting word: fatberg. The word described an increasingly common scenario in the world’s sewer systems, wherein cooking oils and other greases congeal in the pipes, creating sludgy masses that entrap any number of disposed solids. Materials commonly found in fatbergs include wet wipes, sanitary pads, condoms and food scraps. The fatbergs look, in underground photos, like an explosion at the Crisco factory: globby whitish material clinging to the sides of sewer tunnels, waxy chunks breaking off and moving slowly forward on sluggish rivers of grease.