https://en.wikipedia.org/wiki/Flint_water_crisis
"The Flint water crisis is a drinking water contamination issue in Flint, Michigan, United States that started in April 2014. After Flint changed its water source from treated Detroit Water and Sewerage Department water (which was sourced from Lake Huron as well as the Detroit River) to the Flint River (to which officials had failed to apply corrosion inhibitors), its drinking water had a series of problems that culminated with lead contamination, creating a serious public health danger. The Flint River water that was treated improperly caused lead from aging pipes to leach into the water supply, causing extremely elevated levels of the heavy metal neurotoxin."