Examine the steps a municipal water treatment plant in Cincinnati takes to remove particulates, pathogens, and chemicals from river water and make it safe for drinking, in this video from NOVA: Poisoned Water. Treating water from a river, especially an industrialized one like the Flint River in Flint, Michigan, and the Ohio River in Cincinnati, Ohio, is a big challenge. What starts as cloudy water, full of decaying plant matter, bacteria, and surface runoff, is subjected to a series of physical and chemical processes designed to remove obvious as well as invisible impurities. This resource is part of the NOVA Collection.