I do wish the author didn't continually repeat that "rusty pipes" were the causative factor in the Flint crisis, as it was the exposure of lead pipes to highly

I do wish the author didn't continually repeat that "rusty pipes" were the causative factor in the Flint crisis, as it was the exposure of lead pipes to highly corrosive river water that was the primary concern. Having said that, corrosion of iron pipes consumes chlorine used to protect against pathogens, so while the presence of rust was itself an unpleasant but not itself harmful signal, it was symptomatic of the corrosion that unleashed toxic levels of lead and risked the growth of harmful pathogens.