From this article
"The city of Flint, Mich., is in the midst of a water crisis several years in the making. The city opted out of Detroit's water supply and began drawing water from the Flint River in April 2014, part of a cost-saving move. Eighteen months later, in the fall of 2015, researchers discovered that the proportion of children with above-average lead levels in their blood had doubled."
This is not an accident or a mistake. This is not an unexpected result or unpredictable. This is deliberate negligence and deceit.
We can test the properties of a water source and identify what needs to be removed to make it safe to drink. We can design treatment systems to remove metals, organic chemical and adjust the pH so it is not corrosive. We can even use specific chemicals to prevent lead pipes corroding (sodium orthophosphate dosing for plumbosolvency is used in the UK because it is cheaper than *guaranteeing* that all lead pipes have been removed).
There are procedures for signing off design changes to ensure they do not compromise water safety. There are systems for automatically diverting flow if treatment fails or the incoming water is too contaminated to treat.
In the UK, if a water company is found to have failed to take any of these steps, they are subject to fines and prosecution because clean water is vital for EVERYONE'S health.
As a professional engineer working in the water industry, I am utterly disgusted by the utter failure in technical skill, legislative will and professional ethics that have lead this man-made health catastrophe.