CICERO, ILLINOISA noxious odor hits me as soon as I step in the Westside fine screening building at the Stickney Water Reclamation Plant—one of the world’s largest wastewater treatment facilities, located outside of Chicago. In this industrial-looking brick building with exposed pipes, conveyer belts, and clunky machinery are chambers carrying raw sewage—mostly from people’s homes—that will be screened to remove plastic, rags, metals, and other debris.

Standing next to me, operations manager Joe Cummings, listens for a whirring sound. “You’re going to hear the pump running,” he tells me, as every five minutes, a thin suction pipe extracts five tablespoons of turbid, dark-gray untreated wastewater. Over 24 hours each day, this auto sampler will empty raw sewage into a five-gallon plastic jar