[andor436]

The water sources themselves are ok. (They could be much cleaner of course.) It's the aging and decaying infrastructure that brings the water from the source to a Flint homeowner's sink that is causing the issue. Lead is not in the source water; it's in the pipes, solder joints, fixtures, etc. When the State switched Flint over from Detroit's Lake Huron source to the Flint River, the water chemistry change was not correctly accounted for, and thus caused excessive amounts of lead to leach into the water on its way through the system.