Former emergency financial managers of the city of Flint, Michigan face multiple felony charges each carrying a possible 20 year prison sentence relating to that time they switched the municipal water system from mineral rich lake water to mineral poor river water. Companies purporting to traffic in water systems expertise including Veolia and Lockwood, Andrews and Newman which contributed to the situation without considering the critical matter of "What happens inside pipes used to mineral rich lake water when mineral poor river water runs through?"1 face civil action.
The decision to switch water sources was made because of "costs" though the cost of replacing every component of the municipal water system was not included in the initial decision. The region still continues to suffer an apparently unrelated struggle with Legionaries disease.
The answer is that the new water takes up the mineral left by the old and eventually you have water running through bare lead taking up that metal. ↩