The Poisoned City

the series of problems with Flint’s water were connected. Since the switch from Detroit, rapidly corroding iron negated the chlorine treatment. Without the disinfectant, the water was vulnerable to bacteria growth. The first of the E. coli bacteria violations had come a few months after the switch. To combat it, more chlorine was added to the water. But this likely contributed to the spike in TTHMs, the disinfectant by-product that forms in reaction to organic matter. (Organic matter is also more plentiful in the river water, especially when it’s not properly filtered.) As the corrosion worsened, lead leached into the water right along with the iron. 46 The excess iron also turned out to be a perfect nutrient for the growth of other types of bacteria—deadly and, for the time being, undetected.