I'm no longer on city water, but a town close to me that serves the surroundings areas lists its water quality reports yearly. This is info from their webpage. Perhaps it is an alkalinity or pH issue in the water? Our water is pumped from Lake Michigan and then treated to prepare for drinking.

pH 7.5, hardness is pretty consistent year by year at around 150, chlorine 'residuals' at around 1 ppm.

Full reports are on their web page here:
yearly water quality reports full list

2015 city of wyoming water report