Let's see if I can sort this out.
A long series of progressive mayors and city councils increased taxes on businesses. Businesses don't vote. The voters were delighted to receive more stuff and services than they paid for. City payrolls ballooned.
Businesses encountered a rough patch and shut down their operations in high cost places to do business...places like Flint, Michigan.
There is an old saying on Wall Street: "Pigs get fat and hogs get slaughtered."
Flint got slaughtered.
The City of Flint ran into financial trouble when it was not able to trim costs as quickly as revenue dropped, nor or to raise replacement revenue by taxing residents.
The city was placed into State oversight.
The current governor is a Republican. He appointed an executive with wide reaching powers.
One of executives decided to not pay the City of Detroit exorbitant fees for water that Detroit pretty much pumps right out of Lake Huron. This angered the progressives as it cast Detroit in a bad light and reduced City of Detroit revenues.
Water was pumped out of the Flint river and treated.
Residents complained. It tasted different.
Some residents were found to have elevated levels of lead. This is not uncommon in older cities. Interior paints were legally allowed to have lead oxide pigment until about 1977.
The water was tested and some of the samples were found to have excessive levels of lead. The working hypothesis is that lead leached out of the pipes.
Municipal water is supposed to have excess ++Ca ions to "eggshell" the inside of the pipes. This is one reason why soap seems so much foamier at hotels than when showering with "city water". Many hotels have softer water.
The eggshell effect is progressive. Very old pipes have low flow due to the deposition of decades of "eggshell".
The vast amounts of legacy pipes used lead-tin solder. Some of the legacy pipe is actually made of lead.
What was the base rate of lead toxicity in Flint prior to the blow-up about the water? About 2.1%! An amazing thing happened...researchers started looking harder and they found more children with elevated levels of lead.
What was the Detroit Municipal water systems targets for ++Ca, how often was it measured, how was it measured, who recorded it, was it measured in Flint...70 miles from the water plant?
Were pipes disturbed, breaking any existing eggshell? Were new runs of pipe being soldered with lead-tin solder?
It seems fishy that less than one week of the new water ate through fifty years of eggshell accumulation. Is it possible that the Detroit water was deficient in ++Ca to start with? Where were the progressive mayors...why weren't they on top of fifty years of non-performance?
Due diligence would demand that a heightened level of monitoring be started for Detroit tap water, if only because the chemistry leaves the pipes in a fragile condition for other stresses.
To be continued, I am sure.