Sounds like pretty hard water. Possibly from a limestone aquifier.
FWIW the actual input water is not nearly as important as how the tank system is conditioning that water.
For instance the tank's pH is much more dependant on how the tank is removing co2 then whatever the pH of the input water actually is. On my tanks I have a pH of 8.4-8.8 (api high range test kit) because they are blanaced out by live plants which are removing the co2. Even with peat moss in the substrate which lowers the pH and the pH of the input water being much below 7.5 to start with.
my .02